161 results on '"Ng HK"'
Search Results
2. The 2021 WHO Classification of Tumors of the Central Nervous System: a summary
- Author
-
Louis, David N, Perry, Arie, Wesseling, Pieter, Brat, Daniel J, Cree, Ian A, Figarella-Branger, Dominique, Hawkins, Cynthia, Ng, HK, Pfister, Stefan M, Reifenberger, Guido, Soffietti, Riccardo, von Deimling, Andreas, and Ellison, David W
- Subjects
Brain Disorders ,Cancer ,Brain Cancer ,Rare Diseases ,Neurosciences ,Brain ,Central Nervous System ,Central Nervous System Neoplasms ,Humans ,Pathology ,Molecular ,World Health Organization ,brian tumor ,central nervous system ,classification ,diagnosis ,brain tumor ,Oncology and Carcinogenesis ,Oncology & Carcinogenesis - Abstract
The fifth edition of the WHO Classification of Tumors of the Central Nervous System (CNS), published in 2021, is the sixth version of the international standard for the classification of brain and spinal cord tumors. Building on the 2016 updated fourth edition and the work of the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy, the 2021 fifth edition introduces major changes that advance the role of molecular diagnostics in CNS tumor classification. At the same time, it remains wedded to other established approaches to tumor diagnosis such as histology and immunohistochemistry. In doing so, the fifth edition establishes some different approaches to both CNS tumor nomenclature and grading and it emphasizes the importance of integrated diagnoses and layered reports. New tumor types and subtypes are introduced, some based on novel diagnostic technologies such as DNA methylome profiling. The present review summarizes the major general changes in the 2021 fifth edition classification and the specific changes in each taxonomic category. It is hoped that this summary provides an overview to facilitate more in-depth exploration of the entire fifth edition of the WHO Classification of Tumors of the Central Nervous System.
- Published
- 2021
3. cIMPACT‐NOW update 6: new entity and diagnostic principle recommendations of the cIMPACT‐Utrecht meeting on future CNS tumor classification and grading
- Author
-
Louis, David N, Wesseling, Pieter, Aldape, Kenneth, Brat, Daniel J, Capper, David, Cree, Ian A, Eberhart, Charles, Figarella‐Branger, Dominique, Fouladi, Maryam, Fuller, Gregory N, Giannini, Caterina, Haberler, Christine, Hawkins, Cynthia, Komori, Takashi, Kros, Johan M, Ng, HK, Orr, Brent A, Park, Sung‐Hye, Paulus, Werner, Perry, Arie, Pietsch, Torsten, Reifenberger, Guido, Rosenblum, Marc, Rous, Brian, Sahm, Felix, Sarkar, Chitra, Solomon, David A, Tabori, Uri, Bent, Martin J, Deimling, Andreas, Weller, Michael, White, Valerie A, and Ellison, David W
- Subjects
Biomedical and Clinical Sciences ,Oncology and Carcinogenesis ,Cancer ,Rare Diseases ,Central Nervous System Neoplasms ,Humans ,Neoplasm Grading ,brain tumors ,central nervous system ,classification ,neoplasms ,Clinical Sciences ,Neurosciences ,Neurology & Neurosurgery ,Clinical sciences - Abstract
cIMPACT-NOW (the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy) was established to evaluate and make practical recommendations on recent advances in the field of CNS tumor classification, particularly in light of the rapid progress in molecular insights into these neoplasms. For Round 2 of its deliberations, cIMPACT-NOW Working Committee 3 was reconstituted and convened in Utrecht, The Netherlands, for a meeting designed to review putative new CNS tumor types in advance of any future World Health Organization meeting on CNS tumor classification. In preparatory activities for the meeting and at the actual meeting, a list of possible entities was assembled and each type and subtype debated. Working Committee 3 recommended that a substantial number of newly recognized types and subtypes should be considered for inclusion in future CNS tumor classifications. In addition, the group endorsed a number of principles-relating to classification categories, approaches to classification, nomenclature, and grading-that the group hopes will also inform the future classification of CNS neoplasms.
- Published
- 2020
4. Identification of genetic effects underlying type 2 diabetes in South Asian and European populations.
- Author
-
Loh, M, Zhang, W, Ng, HK, Schmid, K, Lamri, A, Tong, L, Ahmad, M, Lee, J-J, Ng, MCY, Petty, LE, Spracklen, CN, Takeuchi, F, Islam, MT, Jasmine, F, Kasturiratne, A, Kibriya, M, Mohlke, KL, Paré, G, Prasad, G, Shahriar, M, Chee, ML, de Silva, HJ, Engert, JC, Gerstein, HC, Mani, KR, Sabanayagam, C, Vujkovic, M, Wickremasinghe, AR, Wong, TY, Yajnik, CS, Yusuf, S, Ahsan, H, Bharadwaj, D, Anand, SS, Below, JE, Boehnke, M, Bowden, DW, Chandak, GR, Cheng, C-Y, Kato, N, Mahajan, A, Sim, X, McCarthy, MI, Morris, AP, Kooner, JS, Saleheen, D, Chambers, JC, Loh, M, Zhang, W, Ng, HK, Schmid, K, Lamri, A, Tong, L, Ahmad, M, Lee, J-J, Ng, MCY, Petty, LE, Spracklen, CN, Takeuchi, F, Islam, MT, Jasmine, F, Kasturiratne, A, Kibriya, M, Mohlke, KL, Paré, G, Prasad, G, Shahriar, M, Chee, ML, de Silva, HJ, Engert, JC, Gerstein, HC, Mani, KR, Sabanayagam, C, Vujkovic, M, Wickremasinghe, AR, Wong, TY, Yajnik, CS, Yusuf, S, Ahsan, H, Bharadwaj, D, Anand, SS, Below, JE, Boehnke, M, Bowden, DW, Chandak, GR, Cheng, C-Y, Kato, N, Mahajan, A, Sim, X, McCarthy, MI, Morris, AP, Kooner, JS, Saleheen, D, and Chambers, JC
- Abstract
South Asians are at high risk of developing type 2 diabetes (T2D). We carried out a genome-wide association meta-analysis with South Asian T2D cases (n = 16,677) and controls (n = 33,856), followed by combined analyses with Europeans (neff = 231,420). We identify 21 novel genetic loci for significant association with T2D (P = 4.7 × 10-8 to 5.2 × 10-12), to the best of our knowledge at the point of analysis. The loci are enriched for regulatory features, including DNA methylation and gene expression in relevant tissues, and highlight CHMP4B, PDHB, LRIG1 and other genes linked to adiposity and glucose metabolism. A polygenic risk score based on South Asian-derived summary statistics shows ~4-fold higher risk for T2D between the top and bottom quartile. Our results provide further insights into the genetic mechanisms underlying T2D, and highlight the opportunities for discovery from joint analysis of data from across ancestral populations.
- Published
- 2022
5. Author Correction: Identification of genetic effects underlying type 2 diabetes in South Asian and European populations.
- Author
-
Loh, M, Zhang, W, Ng, HK, Schmid, K, Lamri, A, Tong, L, Ahmad, M, Lee, J-J, Ng, MCY, Petty, LE, Spracklen, CN, Takeuchi, F, Islam, MT, Jasmine, F, Kasturiratne, A, Kibriya, M, Mohlke, KL, Paré, G, Prasad, G, Shahriar, M, Chee, ML, de Silva, HJ, Engert, JC, Gerstein, HC, Mani, KR, Sabanayagam, C, Vujkovic, M, Wickremasinghe, AR, Wong, TY, Yajnik, CS, Yusuf, S, Ahsan, H, Bharadwaj, D, Anand, SS, Below, JE, Boehnke, M, Bowden, DW, Chandak, GR, Cheng, C-Y, Kato, N, Mahajan, A, Sim, X, McCarthy, MI, Morris, AP, Kooner, JS, Saleheen, D, Chambers, JC, Loh, M, Zhang, W, Ng, HK, Schmid, K, Lamri, A, Tong, L, Ahmad, M, Lee, J-J, Ng, MCY, Petty, LE, Spracklen, CN, Takeuchi, F, Islam, MT, Jasmine, F, Kasturiratne, A, Kibriya, M, Mohlke, KL, Paré, G, Prasad, G, Shahriar, M, Chee, ML, de Silva, HJ, Engert, JC, Gerstein, HC, Mani, KR, Sabanayagam, C, Vujkovic, M, Wickremasinghe, AR, Wong, TY, Yajnik, CS, Yusuf, S, Ahsan, H, Bharadwaj, D, Anand, SS, Below, JE, Boehnke, M, Bowden, DW, Chandak, GR, Cheng, C-Y, Kato, N, Mahajan, A, Sim, X, McCarthy, MI, Morris, AP, Kooner, JS, Saleheen, D, and Chambers, JC
- Published
- 2022
6. Longitudinal molecular trajectories of diffuse glioma in adults
- Author
-
Barthel, FP, Johnson, KC, Varn, FS, Moskalik, AD, Tanner, G, Kocakavuk, E, Anderson, KJ, Abiola, O, Aldape, K, Alfaro, KD, Alpar, D, Amin, SB, Ashley, DM, Bandopadhayay, P, Barnholtz-Sloan, JS, Beroukhim, R, Bock, C, Brastianos, PK, Brat, DJ, Brodbelt, AR, Bruns, AF, Bulsara, KR, Chakrabarty, A, Chakravarti, A, Chuang, JH, Claus, EB, Cochran, EJ, Connelly, J, Costello, JF, Finocchiaro, G, Fletcher, MN, French, PJ, Gan, HK, Gilbert, MR, Gould, PV, Grimmer, MR, Iavarone, A, Ismail, A, Jenkinson, MD, Khasraw, M, Kim, H, Kouwenhoven, MCM, LaViolette, PS, Li, M, Lichter, P, Ligon, KL, Lowman, AK, Malta, TM, Mazor, T, McDonald, KL, Molinaro, AM, Do-Hyun, N, Nayyar, N, Ng, HK, Ngan, CY, Niclou, SP, Niers, JM, Noushmehr, H, Noorbakhsh, J, Ormond, DR, Park, C-K, Poisson, LM, Rabadan, R, Radlwimmer, B, Rao, G, Reifenberger, G, Sa, JK, Schuster, M, Shaw, BL, Short, SC, Smitt, PAS, Sloan, AE, Smits, M, Suzuki, H, Tabatabai, G, Van Meir, EG, Watts, C, Weller, M, Wesseling, P, Westerman, BA, Widhalm, G, Woehrer, A, Yung, WKA, Zadeh, G, Huse, JT, De Groot, JF, Stead, LF, Verhaak, RGW, Barthel, FP, Johnson, KC, Varn, FS, Moskalik, AD, Tanner, G, Kocakavuk, E, Anderson, KJ, Abiola, O, Aldape, K, Alfaro, KD, Alpar, D, Amin, SB, Ashley, DM, Bandopadhayay, P, Barnholtz-Sloan, JS, Beroukhim, R, Bock, C, Brastianos, PK, Brat, DJ, Brodbelt, AR, Bruns, AF, Bulsara, KR, Chakrabarty, A, Chakravarti, A, Chuang, JH, Claus, EB, Cochran, EJ, Connelly, J, Costello, JF, Finocchiaro, G, Fletcher, MN, French, PJ, Gan, HK, Gilbert, MR, Gould, PV, Grimmer, MR, Iavarone, A, Ismail, A, Jenkinson, MD, Khasraw, M, Kim, H, Kouwenhoven, MCM, LaViolette, PS, Li, M, Lichter, P, Ligon, KL, Lowman, AK, Malta, TM, Mazor, T, McDonald, KL, Molinaro, AM, Do-Hyun, N, Nayyar, N, Ng, HK, Ngan, CY, Niclou, SP, Niers, JM, Noushmehr, H, Noorbakhsh, J, Ormond, DR, Park, C-K, Poisson, LM, Rabadan, R, Radlwimmer, B, Rao, G, Reifenberger, G, Sa, JK, Schuster, M, Shaw, BL, Short, SC, Smitt, PAS, Sloan, AE, Smits, M, Suzuki, H, Tabatabai, G, Van Meir, EG, Watts, C, Weller, M, Wesseling, P, Westerman, BA, Widhalm, G, Woehrer, A, Yung, WKA, Zadeh, G, Huse, JT, De Groot, JF, Stead, LF, and Verhaak, RGW
- Abstract
The evolutionary processes that drive universal therapeutic resistance in adult patients with diffuse glioma remain unclear1,2. Here we analysed temporally separated DNA-sequencing data and matched clinical annotation from 222 adult patients with glioma. By analysing mutations and copy numbers across the three major subtypes of diffuse glioma, we found that driver genes detected at the initial stage of disease were retained at recurrence, whereas there was little evidence of recurrence-specific gene alterations. Treatment with alkylating agents resulted in a hypermutator phenotype at different rates across the glioma subtypes, and hypermutation was not associated with differences in overall survival. Acquired aneuploidy was frequently detected in recurrent gliomas and was characterized by IDH mutation but without co-deletion of chromosome arms 1p/19q, and further converged with acquired alterations in the cell cycle and poor outcomes. The clonal architecture of each tumour remained similar over time, but the presence of subclonal selection was associated with decreased survival. Finally, there were no differences in the levels of immunoediting between initial and recurrent gliomas. Collectively, our results suggest that the strongest selective pressures occur during early glioma development and that current therapies shape this evolution in a largely stochastic manner.
- Published
- 2019
7. Spectrum and prevalence of genetic predisposition in medulloblastoma: a retrospective genetic study and prospective validation in a clinical trial cohort
- Author
-
Waszak, SM, Northcott, PA, Buchhalter, I, Robinson, GW, Sutter, C, Groebner, S, Grund, KB, Brugières, L, Jones, DTW, Pajtler, KW, Morrissy, AS, Kool, M, Sturm, D, Chavez, L, Ernst, A, Brabetz, S, Hain, M, Zichner, T, Segura-Wang, M, Weischenfeldt, J, Rausch, T, Mardin, BR, Zhou, X, Baciu, C, Lawerenz, C, Chan, JA, Varlet, P, Guerrini-Rousseau, L, Fults, DW, Grajkowska, W, Hauser, P, Jabado, N, Ra, YS, Zitterbart, K, Shringarpure, SS, De La Vega, FM, Bustamante, CD, Ng, HK, Perry, A, MacDonald, TJ, Hernáiz Driever, P, Bendel, AE, Bowers, DC, McCowage, G, Chintagumpala, MM, Cohn, R, Hassall, T, Fleischhack, G, Eggen, T, Wesenberg, F, Feychting, M, Lannering, B, Schüz, J, Johansen, C, Andersen, TV, Röösli, M, Kuehni, CE, Grotzer, M, Kjaerheim, K, Monoranu, CM, Archer, TC, Duke, E, Pomeroy, SL, Shelagh, R, Frank, S, Sumerauer, D, Scheurlen, W, Ryzhova, MV, Milde, T, Kratz, CP, Samuel, D, Zhang, J, Solomon, DA, Marra, M, Eils, R, Bartram, CR, von Hoff, K, Rutkowski, S, Ramaswamy, V, Gilbertson, RJ, Korshunov, A, Taylor, MD, Lichter, P, Malkin, D, Gajjar, A, Korbel, JO, Pfister, SM, Waszak, SM, Northcott, PA, Buchhalter, I, Robinson, GW, Sutter, C, Groebner, S, Grund, KB, Brugières, L, Jones, DTW, Pajtler, KW, Morrissy, AS, Kool, M, Sturm, D, Chavez, L, Ernst, A, Brabetz, S, Hain, M, Zichner, T, Segura-Wang, M, Weischenfeldt, J, Rausch, T, Mardin, BR, Zhou, X, Baciu, C, Lawerenz, C, Chan, JA, Varlet, P, Guerrini-Rousseau, L, Fults, DW, Grajkowska, W, Hauser, P, Jabado, N, Ra, YS, Zitterbart, K, Shringarpure, SS, De La Vega, FM, Bustamante, CD, Ng, HK, Perry, A, MacDonald, TJ, Hernáiz Driever, P, Bendel, AE, Bowers, DC, McCowage, G, Chintagumpala, MM, Cohn, R, Hassall, T, Fleischhack, G, Eggen, T, Wesenberg, F, Feychting, M, Lannering, B, Schüz, J, Johansen, C, Andersen, TV, Röösli, M, Kuehni, CE, Grotzer, M, Kjaerheim, K, Monoranu, CM, Archer, TC, Duke, E, Pomeroy, SL, Shelagh, R, Frank, S, Sumerauer, D, Scheurlen, W, Ryzhova, MV, Milde, T, Kratz, CP, Samuel, D, Zhang, J, Solomon, DA, Marra, M, Eils, R, Bartram, CR, von Hoff, K, Rutkowski, S, Ramaswamy, V, Gilbertson, RJ, Korshunov, A, Taylor, MD, Lichter, P, Malkin, D, Gajjar, A, Korbel, JO, and Pfister, SM
- Abstract
Background: Medulloblastoma is associated with rare hereditary cancer predisposition syndromes; however, consensus medulloblastoma predisposition genes have not been defined and screening guidelines for genetic counselling and testing for paediatric patients are not available. We aimed to assess and define these genes to provide evidence for future screening guidelines. Methods: In this international, multicentre study, we analysed patients with medulloblastoma from retrospective cohorts (International Cancer Genome Consortium [ICGC] PedBrain, Medulloblastoma Advanced Genomics International Consortium [MAGIC], and the CEFALO series) and from prospective cohorts from four clinical studies (SJMB03, SJMB12, SJYC07, and I-HIT-MED). Whole-genome sequences and exome sequences from blood and tumour samples were analysed for rare damaging germline mutations in cancer predisposition genes. DNA methylation profiling was done to determine consensus molecular subgroups: WNT (MB WNT ), SHH (MB SHH ), group 3 (MB Group3 ), and group 4 (MB Group4 ). Medulloblastoma predisposition genes were predicted on the basis of rare variant burden tests against controls without a cancer diagnosis from the Exome Aggregation Consortium (ExAC). Previously defined somatic mutational signatures were used to further classify medulloblastoma genomes into two groups, a clock-like group (signatures 1 and 5) and a homologous recombination repair deficiency-like group (signatures 3 and 8), and chromothripsis was investigated using previously established criteria. Progression-free survival and overall survival were modelled for patients with a genetic predisposition to medulloblastoma. Findings: We included a total of 1022 patients with medulloblastoma from the retrospective cohorts (n=673) and the four prospective studies (n=349), from whom blood samples (n=1022) and tumour samples (n=800) were analysed for germline mutations in 110 cancer predisposition genes. In our rare variant burden analysis, we co
- Published
- 2018
8. Glioma through the looking GLASS: molecular evolution of diffuse gliomas and the Glioma Longitudinal Analysis Consortium
- Author
-
Aldape, K, Amin, SB, Ashley, DM, Barnholtz-Sloan, JS, Bates, AJ, Beroukhim, R, Bock, C, Brat, DJ, Claus, EB, Costello, JF, de Groot, JF, Finocchiaro, G, French, PJ, Gan, HK, Griffith, B, Herold-Mende, CC, Horbinski, C, Iavarone, A, Kalkanis, SN, Karabatsou, K, Kim, H, Kouwenhoven, MCM, McDonald, KL, Miletic, H, Nam, D-H, Ng, HK, Niclou, SP, Noushmehr, H, Ormond, DR, Poisson, LM, Reifenberger, G, Roncaroli, F, Sa, JK, Smitt, PAES, Smits, M, Souza, CF, Tabatabai, G, Van Meir, EG, Verhaak, RGW, Watts, C, Wesseling, P, Woehrer, A, Yung, WKA, Jungk, C, Hau, A-C, van Dyck, E, Westerman, BA, Yin, J, Abiola, O, Zeps, N, Grimmond, S, Buckland, M, Khasraw, M, Sulman, EP, Muscat, AM, Stead, L, Aldape, K, Amin, SB, Ashley, DM, Barnholtz-Sloan, JS, Bates, AJ, Beroukhim, R, Bock, C, Brat, DJ, Claus, EB, Costello, JF, de Groot, JF, Finocchiaro, G, French, PJ, Gan, HK, Griffith, B, Herold-Mende, CC, Horbinski, C, Iavarone, A, Kalkanis, SN, Karabatsou, K, Kim, H, Kouwenhoven, MCM, McDonald, KL, Miletic, H, Nam, D-H, Ng, HK, Niclou, SP, Noushmehr, H, Ormond, DR, Poisson, LM, Reifenberger, G, Roncaroli, F, Sa, JK, Smitt, PAES, Smits, M, Souza, CF, Tabatabai, G, Van Meir, EG, Verhaak, RGW, Watts, C, Wesseling, P, Woehrer, A, Yung, WKA, Jungk, C, Hau, A-C, van Dyck, E, Westerman, BA, Yin, J, Abiola, O, Zeps, N, Grimmond, S, Buckland, M, Khasraw, M, Sulman, EP, Muscat, AM, and Stead, L
- Abstract
Adult diffuse gliomas are a diverse group of brain neoplasms that inflict a high emotional toll on patients and their families. The Cancer Genome Atlas and similar projects have provided a comprehensive understanding of the somatic alterations and molecular subtypes of glioma at diagnosis. However, gliomas undergo significant cellular and molecular evolution during disease progression. We review the current knowledge on the genomic and epigenetic abnormalities in primary tumors and after disease recurrence, highlight the gaps in the literature, and elaborate on the need for a new multi-institutional effort to bridge these knowledge gaps and how the Glioma Longitudinal Analysis Consortium (GLASS) aims to systemically catalog the longitudinal changes in gliomas. The GLASS initiative will provide essential insights into the evolution of glioma toward a lethal phenotype, with the potential to reveal targetable vulnerabilities and, ultimately, improved outcomes for a patient population in need.
- Published
- 2018
9. miREM: an expectation-maximization approach for prioritizing miRNAs associated with gene-set
- Author
-
Hadi, LHA, Lin, QXX, Tri, TM, Loh, M, Ng, HK, Salim, A, Soong, R, Benoukraf, T, Hadi, LHA, Lin, QXX, Tri, TM, Loh, M, Ng, HK, Salim, A, Soong, R, and Benoukraf, T
- Abstract
BACKGROUND: The knowledge of miRNAs regulating the expression of sets of mRNAs has led to novel insights into numerous and diverse cellular mechanisms. While a single miRNA may regulate many genes, one gene can be regulated by multiple miRNAs, presenting a complex relationship to model for accurate predictions. RESULTS: Here, we introduce miREM, a program that couples an expectation-maximization (EM) algorithm to the common approach of hypergeometric probability (HP), which improves the prediction and prioritization of miRNAs from gene-sets of interest. miREM has been made available through a web-server ( https://bioinfo-csi.nus.edu.sg/mirem2/ ) that can be accessed through an intuitive graphical user interface. The program incorporates a large compendium of human/mouse miRNA-target prediction databases to enhance prediction. Users may upload their genes of interest in various formats as an input and select whether to consider non-conserved miRNAs, amongst filtering options. Results are reported in a rich graphical interface that allows users to: (i) prioritize predicted miRNAs through a scatterplot of HP p-values and EM scores; (ii) visualize the predicted miRNAs and corresponding genes through a heatmap; and (iii) identify and filter homologous or duplicated predictions by clustering them according to their seed sequences. CONCLUSION: We tested miREM using RNAseq datasets from two single "spiked" knock-in miRNA experiments and two double knock-out miRNA experiments. miREM predicted these manipulated miRNAs as having high EM scores from the gene set signatures (i.e. top predictions for single knock-in and double knock-out miRNA experiments). Finally, we have demonstrated that miREM predictions are either similar or better than results provided by existing programs.
- Published
- 2018
10. Structural characterisation of the interaction between Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) and their human ligands in severe malaria
- Author
-
Ng, HK and Higgins, M
- Subjects
Molecular biophysics (biochemistry) - Abstract
Sequestration of infected erythrocytes during P. falciparum infection can lead to severe malaria. PfEMP1 proteins are central to this process. Multimodular PfEMP1 proteins can bind to a variety of human ligands due to the presence of CIDR and DBL domains. CIDR and DBL domains are classified to three and six families respectively, with each thought to bind to unique human ligands. The interaction between PfEMP1 proteins and human ligands protects the infected erythrocytes against spleen-mediated destruction. Additionally, these PfEMP1 proteins undergo antigenic variation to evade immune surveillance. They also elicit immune suppression by binding to immunoglobulins within the circulatory system. The work described here focuses on two interactions between PfEMP1 on the infected erythrocytes and their human ligands, the first involving CD36 and CIDR1α domains and the second involving human IgM and DBL domains. I have expressed and purified recombinant proteins involved in both interactions. In this thesis, I have confirmed using a variety of biophysical methods that CIDR1α domains are able to bind CD36 in a 1:1 binding stoichiometry, and this accounts for the binding affinity of the full length protein. This interaction was not disrupted after performing deglycosylation procedures on CD36, allowing me to obtain stable complexes of these interacting partners for structural characterisation by crystallography. I have also confirmed the interaction between DBL domains and human IgM Fc region using similar biophysical methods. These experiments are important for paving the way towards further structural characterisation of these interactions that leads to sequestration. .
- Published
- 2017
11. Numerical Simulations of Constant-Volume Spray Combustion of n-Heptane with Chemical Kinetics
- Author
-
Tan, JY, Ng, HK, Gan, S, Bonatesta, F, Tan, JY, Ng, HK, Gan, S, and Bonatesta, F
- Abstract
Objectives: A reduced toluene reference fuel (TRF) mechanism of multi-component nature from the literature is utilized to simulate constant-volume spray combustion of n-heptane. The approach allows a preliminary assessment of fuel kinetic model and computational fluid dynamics (CFD) formulations in a simplified computational domain before integrating them in complex engine simulations. Methods: The operating conditions vary in ambient densities between 14.8 kg/m3 and 30 kg/m3 with initial oxygen concentrations ranging from 10% to 21%. The CFD models are first calibrated to replicate spray penetration lengths of the non-reacting condition. The tuned numerical models are then applied to simulate the combustion and soot formation events of reacting sprays. The soot model employed is the multi-step Moss-Brookes model with updated oxidation models. Findings: The relative errors for ignition delay and lift-off length predictions are within 35% and 22% respectively. Furthermore, simulated soot volume fraction contours agree qualitatively with the experimental soot clouds. Computed peak soot locations, however, are found to be further downstream axially as compared to the experimental results across all test cases. Application: Good agreement with experimental spatial soot distributions allows the incorporation of both fuel and soot models in engine configurations.
- Published
- 2017
12. Prognostic value of medulloblastoma extent of resection after accounting for molecular subgroup: a retrospective integrated clinical and molecular analysis
- Author
-
Thompson, EM, Hielscher, T, Bouffet, E, Remke, M, Luu, B, Gururangan, S, McLendon, RE, Bigner, DD, Lipp, ES, Perreault, S, Cho, YJ, Grant, G, Kim, SK, Lee, JY, Rao, AAN, Giannini, C, Li, KKW, Ng, HK, Yao, Y, Kumabe, T, Tominaga, T, Grajkowska, WA, Perek-Polnik, M, Low, DCY, Seow, WT, Chang, KTE, Mora, J, Pollack, IF, Hamilton, RL, Leary, S, Moore, AS, Ingram, WJ, Hallahan, AR, Jouvet, A, Fèvre-Montange, M, Vasiljevic, A, Faure-Conter, C, Shofuda, T, Kagawa, N, Hashimoto, N, Jabado, N, Weil, AG, Gayden, T, Wataya, T, Shalaby, T, Grotzer, M, Zitterbart, K, Sterba, J, Kren, L, Hortobágyi, T, Klekner, A, László, B, Pócza, T, Hauser, P, Schüller, U, Jung, S, Jang, WY, French, PJ, Kros, JM, van Veelen, MLC, Massimi, L, Leonard, JR, Rubin, JB, Vibhakar, R, Chambless, LB, Cooper, MK, Thompson, RC, Faria, CC, Carvalho, A, Nunes, S, Pimentel, J, Fan, X, Muraszko, KM, López-Aguilar, E, Lyden, D, Garzia, L, Shih, DJH, Kijima, N, Schneider, C, Adamski, J, Northcott, PA, Kool, M, Jones, DTW, Chan, JA, Nikolic, A, Garre, ML, Van Meir, EG, Osuka, S, Olson, JJ, Jahangiri, A, and Castro, BA
- Subjects
Adult ,Male ,Canada ,Brain Neoplasms ,Infant ,Prognosis ,Magnetic Resonance Imaging ,Combined Modality Therapy ,Disease-Free Survival ,Child, Preschool ,Disease Progression ,Humans ,Female ,Child ,Medulloblastoma ,Retrospective Studies - Abstract
© 2016 Elsevier Ltd Background Patients with incomplete surgical resection of medulloblastoma are controversially regarded as having a marker of high-risk disease, which leads to patients undergoing aggressive surgical resections, so-called second-look surgeries, and intensified chemoradiotherapy. All previous studies assessing the clinical importance of extent of resection have not accounted for molecular subgroup. We analysed the prognostic value of extent of resection in a subgroup-specific manner. Methods We retrospectively identified patients who had a histological diagnosis of medulloblastoma and complete data about extent of resection and survival from centres participating in the Medulloblastoma Advanced Genomics International Consortium. We collected from resections done between April, 1997, and February, 2013, at 35 international institutions. We established medulloblastoma subgroup affiliation by gene expression profiling on frozen or formalin-fixed paraffin-embedded tissues. We classified extent of resection on the basis of postoperative imaging as gross total resection (no residual tumour), near-total resection (30 Gy vs no craniospinal irradiation). The primary analysis outcome was the effect of extent of resection by molecular subgroup and the effects of other clinical variables on overall and progression-free survival. Findings We included 787 patients with medulloblastoma (86 with WNT tumours, 242 with SHH tumours, 163 with group 3 tumours, and 296 with group 4 tumours) in our multivariable Cox models of progression-free and overall survival. We found that the prognostic benefit of increased extent of resection for patients with medulloblastoma is attenuated after molecular subgroup affiliation is taken into account. We identified a progression-free survival benefit for gross total resection over sub-total resection (hazard ratio [HR] 1·45, 95% CI 1·07–1·96, p=0·16) but no overall survival benefit (HR 1·23, 0·87–1·72, p=0·24). We saw no progression-free survival or overall survival benefit for gross total resection compared with near-total resection (HR 1·05, 0·71–1·53, p=0·8158 for progression-free survival and HR 1·14, 0·75–1·72, p=0·55 for overall survival). No significant survival benefit existed for greater extent of resection for patients with WNT, SHH, or group 3 tumours (HR 1·03, 0·67–1·58, p=0·89 for sub-total resection vs gross total resection). For patients with group 4 tumours, gross total resection conferred a benefit to progression-free survival compared with sub-total resection (HR 1·97, 1·22–3·17, p=0·0056), especially for those with metastatic disease (HR 2·22, 1·00–4·93, p=0·050). However, gross total resection had no effect on overall survival compared with sub-total resection in patients with group 4 tumours (HR 1·67, 0·93–2·99, p=0·084). Interpretation The prognostic benefit of increased extent of resection for patients with medulloblastoma is attenuated after molecular subgroup affiliation is taken into account. Although maximum safe surgical resection should remain the standard of care, surgical removal of small residual portions of medulloblastoma is not recommended when the likelihood of neurological morbidity is high because there is no definitive benefit to gross total resection compared with near-total resection. Funding Canadian Cancer Society Research Institute, Terry Fox Research Institute, Canadian Institutes of Health Research, National Institutes of Health, Pediatric Brain Tumor Foundation, and the Garron Family Chair in Childhood Cancer Research.
- Published
- 2016
- Full Text
- View/download PDF
13. LG-46INFERIOR OUTCOME AND POOR RESPONSE TO CONVENTIONAL THERAPIES IN PEDIATRIC LOW-GRADE GLIOMAS HARBORING THE BRAF V600E MUTATION
- Author
-
Lassaletta, Alvaro, primary, Mistry, Matthew, additional, Arnaldo, Anthony, additional, Ryall, Scott, additional, Guerreiro-Stucklin, Ana, additional, Krishnatry, Rahul, additional, Ling, Cino, additional, Honnorat, Marion, additional, Zhukova, Nataliya, additional, Zapotocky, Michal, additional, McKeown, Tara, additional, Ramaswamy, Vijay, additional, Bartels, Ute, additional, Huang, Annie, additional, Jabado, Nada, additional, Cruz, Ofelia, additional, de Torres, Carmen, additional, Cherry, Ho, additional, Packer, Roger, additional, Tatevossian, Ruth, additional, Ellison, David, additional, Harreld, Julie, additional, Dalton, Jim, additional, Mulcahy-Levy, Jean, additional, Foreman, Nicholas, additional, Karajannis, Matthias, additional, Mueller, Sabine, additional, Nicolaides, Theodore, additional, Eisenstat, David, additional, Carret, Anne-Sophie, additional, Kieran, Mark, additional, Ligon, Keith, additional, Jouvet, Anne, additional, Perbert, Romain, additional, Vasiljevic, Alex, additional, Frappaz, Didier, additional, Joly, Marie Odile, additional, Chambeless, Lola, additional, Thompson, Reid, additional, Rao, Amulya Nageswara, additional, Chan, Aden, additional, NG, Hk, additional, Garre, Maria Luisa, additional, Nozza, Paolo, additional, Massimino, Maura, additional, Leary, Sarah, additional, Crane, Courtney, additional, Bouffet, Eric, additional, Hawkins, Cynthia, additional, and Tabori, Uri, additional
- Published
- 2016
- Full Text
- View/download PDF
14. Intertumoral Heterogeneity within Medulloblastoma Subgroups
- Author
-
Luca Massimi, Caterina Giannini, Betty Luu, Cynthia Hawkins, Byung Kyu Cho, James T. Rutka, G. Yancey Gillespie, Timothy E. Van Meter, Almos Klekner, Young Shin Ra, Carolina Nor, Anna Goldenberg, Rajeev Vibhakar, Hideo Nakamura, Gaetano Finocchiaro, Massimo Zollo, John Peacock, Marta Perek-Polnik, Keren Isaev, Alvaro Lassaletta, Amulya A. Nageswara Rao, Florence M.G. Cavalli, Maura Massimino, Livia Garzia, Jüri Reimand, Charles G. Eberhart, Maryam Fouladi, Enrique López-Aguilar, Annie Huang, Cécile Faure-Conter, Gary D. Bader, Jaume Mora, Ho Keung Ng, James M. Olson, Jennifer A. Chan, Erwin G. Van Meir, Daniela Pretti da Cunha Tirapelli, Hamza Farooq, Fernando Chico Ponce de León, Linda M. Liau, Kay Ka Wai Li, Shenandoah Robinson, Anne Jouvet, Tomoko Shofuda, José Pimentel, Reid C. Thompson, Yuan Yao Thompson, Ian F. Pollack, Nada Jabado, Boleslaw Lach, Pim J. French, Joshua B. Rubin, Eric Bouffet, Alexandre Vasiljevic, Ali G. Saad, Michael K. Cooper, Satoru Osuka, Peter B. Dirks, Jaroslav Sterba, Johan M. Kros, Claudia C. Faria, Kyu-Chang Wang, Seung-Ki Kim, Shin Jung, Craig Daniels, A. Sorana Morrissy, Ladislav Rampášek, Andrew R. Hallahan, Sarah Leary, Wiesława Grajkowska, Uri Tabori, Marc Remke, Samer K. Elbabaa, Michael D. Taylor, Andrew S. Moore, Toshihiro Kumabe, Mario Perezpeña-Diazconti, Vijay Ramaswamy, Ronald L. Hamilton, Claudia M. Kuzan-Fischer, Marie Lise C. van Veelen, Helen Wheeler, Michal Zapotocky, Ji Yeoun Lee, David Shih, Jeffrey R. Leonard, Karel Zitterbart, Carlos Gilberto Carlotti, Steffen Albrecht, Jonathon Torchia, Peter Hauser, Ute Bartels, William A. Weiss, Sameer Agnihotri, Lola B. Chambless, Neurosurgery, Pathology, Neurology, Cavalli, Fmg, Remke, M, Rampasek, L, Peacock, J, Shih, Djh, Luu, B, Garzia, L, Torchia, J, Nor, C, Morrissy, A, Agnihotri, S, Thompson, Yy, Kuzan-Fischer, Cm, Farooq, H, Isaev, K, Daniels, C, Cho, Bk, Kim, Sk, Wang, Kc, Lee, Jy, Grajkowska, Wa, Perek-Polnik, M, Vasiljevic, A, Faure-Conter, C, Jouvet, A, Giannini, C, Nageswara Rao, Aa, Li, Kkw, Ng, Hk, Eberhart, Cg, Pollack, If, Hamilton, Rl, Gillespie, Gy, Olson, Jm, Leary, S, Weiss, Wa, Lach, B, Chambless, Lb, Thompson, Rc, Cooper, Mk, Vibhakar, R, Hauser, P, van Veelen, Mc, Kros, Jm, French, Pj, Ra, Y, Kumabe, T, López-Aguilar, E, Zitterbart, K, Sterba, J, Finocchiaro, G, Massimino, M, Van Meir, Eg, Osuka, S, Shofuda, T, Klekner, A, Zollo, M, Leonard, Jr, Rubin, Jb, Jabado, N, Albrecht, S, Mora, J, Van Meter, Te, Jung, S, Moore, A, Hallahan, Ar, Chan, Ja, Tirapelli, Dpc, Carlotti, Cg, Fouladi, M, Pimentel, J, Faria, Cc, Saad, Ag, Massimi, L, Liau, Lm, Wheeler, H, Nakamura, H, Elbabaa, Sk, Perezpeña-Diazconti, M, Chico Ponce de León, F, Robinson, S, Zapotocky, M, Lassaletta, A, Huang, Weiping, Hawkins, Ce, Tabori, U, Bouffet, E, Bartels, U, Dirks, Pb, Rutka, Jt, Bader, Gd, Reimand, J, Goldenberg, A, Ramaswamy, V, Taylor, Md, Cavalli F.M.G., Remke M., Rampasek L., Peacock J., Shih D.J.H., Luu B., Garzia L., Torchia J., Nor C., Morrissy A.S., Agnihotri S., Thompson Y.Y., Kuzan-Fischer C.M., Farooq H., Isaev K., Daniels C., Cho B.-K., Kim S.-K., Wang K.-C., Lee J.Y., Grajkowska W.A., Perek-Polnik M., Vasiljevic A., Faure-Conter C., Jouvet A., Giannini C., Nageswara Rao A.A., Li K.K.W., Ng H.-K., Eberhart C.G., Pollack I.F., Hamilton R.L., Gillespie G.Y., Olson J.M., Leary S., Weiss W.A., Lach B., Chambless L.B., Thompson R.C., Cooper M.K., Vibhakar R., Hauser P., van Veelen M.-L.C., Kros J.M., French P.J., Ra Y.S., Kumabe T., Lopez-Aguilar E., Zitterbart K., Sterba J., Finocchiaro G., Massimino M., Van Meir E.G., Osuka S., Shofuda T., Klekner A., Zollo M., Leonard J.R., Rubin J.B., Jabado N., Albrecht S., Mora J., Van Meter T.E., Jung S., Moore A.S., Hallahan A.R., Chan J.A., Tirapelli D.P.C., Carlotti C.G., Fouladi M., Pimentel J., Faria C.C., Saad A.G., Massimi L., Liau L.M., Wheeler H., Nakamura H., Elbabaa S.K., Perezpena-Diazconti M., Chico Ponce de Leon F., Robinson S., Zapotocky M., Lassaletta A., Huang A., Hawkins C.E., Tabori U., Bouffet E., Bartels U., Dirks P.B., Rutka J.T., Bader G.D., Reimand J., Goldenberg A., Ramaswamy V., and Taylor M.D.
- Subjects
0301 basic medicine ,Cancer Research ,medulloblastoma ,CURRENT CONSENSUS ,copy number ,Bioinformatics ,subgroups ,Cohort Studies ,Individual data ,Cluster Analysis ,R PACKAGE ,Precision Medicine ,GENECHIP DATA ,Sonic hedgehog ,ADULT MEDULLOBLASTOMA ,DNA Copy Number Variation ,Cancer ,Pediatric ,Genomics ,methylation ,CANCER ,3. Good health ,Oncology ,DNA methylation ,Human ,Pediatric Research Initiative ,DNA Copy Number Variations ,Pediatric Cancer ,Oncology and Carcinogenesis ,Computational biology ,Biology ,Article ,CLASSIFICATION ,Homogeneous clusters ,03 medical and health sciences ,Rare Diseases ,Genetics ,medicine ,Humans ,Oncology & Carcinogenesis ,Cerebellar Neoplasms ,RECURRENCE ,neoplasms ,Medulloblastoma ,Cluster Analysi ,gene expression ,MUTATIONS ,subgroup ,Gene Expression Profiling ,Human Genome ,Neurosciences ,integrative clustering ,DNA Methylation ,medicine.disease ,Precision medicine ,MEDULOBLASTOMA ,Brain Disorders ,nervous system diseases ,Brain Cancer ,Gene expression profiling ,stomatognathic diseases ,030104 developmental biology ,Genomic ,biology.protein ,MOLECULAR SUBGROUPS ,GENOMIC DATA ,Cohort Studie - Abstract
While molecular subgrouping has revolutionized medulloblastoma classification, the extent of heterogeneity within subgroups is unknown. Similarity network fusion (SNF) applied to genome-wide DNA methylation and gene expression data across 763 primary samples identifies very homogeneous clusters of patients, supporting the presence of medulloblastoma subtypes. After integration of somatic copy-number alterations, and clinical features specific to each cluster, we identify 12 different subtypes of medulloblastoma. Integrative analysis using SNF further delineates group 3 from group 4 medulloblastoma, which is not as readily apparent through analyses of individual data types. Two clear subtypes of infants with Sonic Hedgehog medulloblastoma with disparate outcomes and biology are identified. Medulloblastoma subtypes identified through integrative clustering have important implications for stratification of future clinical trials.
- Published
- 2017
15. High detection rate of circulating-tumor DNA from cerebrospinal fluid of children with central nervous system germ cell tumors.
- Author
-
Nakano Y, Burns I, Nobre L, Siddaway R, Rana M, Nesvick C, Bondoc A, Ku M, Yuditskiy R, Ku DTL, Shing MMK, Cheng KKF, Ng HK, Das A, Bennett J, Ramaswamy V, Huang A, Malkin D, Ertl-Wagner B, Dirks P, Bouffet E, Bartels U, Tabori U, Hawkins C, and Liu APY
- Subjects
- Humans, Child, Male, Adolescent, Female, Child, Preschool, Circulating Tumor DNA cerebrospinal fluid, Circulating Tumor DNA genetics, Neoplasms, Germ Cell and Embryonal cerebrospinal fluid, Neoplasms, Germ Cell and Embryonal genetics, Neoplasms, Germ Cell and Embryonal diagnosis, Central Nervous System Neoplasms cerebrospinal fluid, Central Nervous System Neoplasms genetics, Central Nervous System Neoplasms diagnosis, Biomarkers, Tumor cerebrospinal fluid, Biomarkers, Tumor genetics
- Abstract
Central nervous system germ cell tumors (CNS-GCT) are malignant neoplasms that arise predominantly during adolescence and young adulthood. These tumors are typically sensitive to treatment, but resulting long-term health deficits are common. Additional clinical challenges include surgical risks associated with tumor biopsy, and need to determine treatment response for adapting radiotherapy protocols. The aim of this study was to establish the detectability of circulating-tumor DNA (ctDNA) from cerebrospinal fluid (CSF) of children with CNS-GCT as a potential biomarker. We obtained CSF from patients with CNS-GCT by lumbar puncture or intra-operatively. Cell-free DNA (cfDNA) was extracted and subjected to low-pass whole genome sequencing (LP-WGS). Copy-number alterations (CNAs) were inferred and served as a marker of measurable residual disease (MRD). Comparisons with imaging findings and tumor marker levels were made. A total of 29 CSF samples from 21 patients (16 with germinoma, 5 with non-germinomatous GCT) were sequenced. Twenty samples from 19 patients were collected at diagnosis, and 9 samples from 7 patients were collected during or after therapy. Among the diagnostic samples, CNAs were detected in samples from 17/19 patients (89%), which included 8 with marker-negative tumors. Specific clinical scenarios suggested that serial cfDNA analysis may carry utility in tracking treatment responses as well as clarifying indeterminate imaging findings. Our results provide evidence for the high-sensitivity in detecting ctDNA from CSF of CNS-GCT patients using LP-WGS, with potential utility for non-invasive diagnosis and disease monitoring in upcoming CNS-GCT studies., Competing Interests: Declarations. Ethics approval and consent to participate: This study was approved by the Hospital for Sick Children Research Ethical Board (REB # 1000071241) and the Hong Kong Children’s Hospital Research Ethics Committee (HKCH-REC-2020-068). Written informed consent was obtained from all patients, their parents or guardians. Consent for publication: Written informed consent for the publication was obtained from all patients participants, their parents or guardians. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
16. The molecular history of IDH-mutant astrocytomas without adjuvant treatment.
- Author
-
Shi ZF, Li KK, Kwan JS, Chung NY, Wong SC, Chu AW, Chen H, Chan DT, Mao Y, and Ng HK
- Abstract
Hypermutation and malignant transformation are potential complications arising from temozolomide treatment of IDH-mutant gliomas. However, the natural history of IDH-mutant low-grade gliomas without temozolomide treatment is actually under-studied. We retrieved retrospectively from our hospitals paired tumors from 19 patients with IDH-mutant, 1p19q non-codeleted Grade 2 astrocytomas where no interim adjuvant treatment with either temozolomide or radiotherapy was given between primary resections and first recurrences. Tissues from multiple recurrences were available from two patients and radiotherapy but not temozolomide was given before the last specimens were resected. We studied the natural molecular history of these low-grade IDH-mutant astrocytomas without pressure of temozolomide with DNA methylation profiling and copy number variation (CNV) analyses, targeted DNA sequencing, TERTp sequencing, FISH for ALT and selected biomarkers. Recurrences were mostly higher grades (15/19 patients) and characterized by new CNVs not present in the primary tumors (17/19 cases). Few novel mutations were identified in recurrences. Tumors from 17/19 (89.5%) patients showed either CDKN2A homozygous deletion, MYC or PDGFRA focal and non-focal gains at recurrences. There was no case of hypermutation. Phylogenetic trees constructed for tumors for the two patients with multiple recurrences suggested a lack of subclone development in their evolution when under no pressure from temozolomide. In summary, our studies demonstrated, in contrast to the phenomenon of temozolomide-induced hypermutation, IDH-mutant, 1p19q non-codeleted Grade 2 astrocytomas which had not been treated by temozolomide, acquired new CNVs at tumor recurrences. These findings improve our understanding of the molecular life history of IDH-mutant astrocytomas., (© 2024 The Author(s). Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology.)
- Published
- 2024
- Full Text
- View/download PDF
17. Development of Cashew and Pistachio Ladders through a Food-Processing Approach.
- Author
-
Shwe Yee N, Ng HK, Zeng J, Bao J, Campbell DE, Turner PJ, and Lee NA
- Abstract
Following successful oral immunotherapy (OIT) for peanut allergy using boiled peanuts (BOPI trial), this study investigated the potential of wet-thermal-processing-induced allergen modification, specifically soaking and boiling (1-4 h) to reduce the allergenicity of cashew and pistachio allergens. In addition, this study provides a foundation of understanding for developing safer forms of cashew/pistachio administration for application in OIT by gradual exposure to increasing doses of modified allergens with reduced potency as an "allergen ladder". An SDS-PAGE analysis and an intrinsic-fluorescence spectroscopy revealed altered tertiary structures of the allergens, leading to their denaturation and even degradation. Notably, the reduction in both allergen-specific polyclonal IgG and human-specific IgE (sIgE) binding correlated with the treatment time, with the most significant decrease observed after 4 h of boiling. In contrast, shorter soaking treatments showed negligible effects on the IgE-binding capacity of these nuts, therefore indicating a further need for optimization. These findings indicate that extended boiling effectively reduced the amounts of the highly potent allergenic component Ana o 3 in cashew and Pis v 1 in pistachio, as confirmed by ELISA using polyclonal anti-Ana o 3 antibodies, and an immunoblot showed decreased IgE epitope binding in cashew and pistachio allergens, which further modified their allergenic profiles. This approach shows promise as a viable method for offering a safer therapeutic option for cashew/pistachio allergy.
- Published
- 2024
- Full Text
- View/download PDF
18. Adiposity and metabolic health in Asian populations: an epidemiological study using dual-energy x-ray absorptiometry in Singapore.
- Author
-
Mina T, Xie W, Low DY, Wang X, Lam BCC, Sadhu N, Ng HK, Aziz NA, Tong TYY, Kerk SK, Choo WL, Low GL, Ibrahim H, Lim L, Tai ES, Wansaicheong G, Dalan R, Yew YW, Elliott P, Riboli E, Loh M, Ngeow J, Lee ES, Lee J, Best J, and Chambers J
- Subjects
- Humans, Male, Female, Middle Aged, Singapore epidemiology, Aged, Adult, Cross-Sectional Studies, Aged, 80 and over, Asian People statistics & numerical data, Metabolic Syndrome epidemiology, Metabolic Syndrome ethnology, Obesity epidemiology, Obesity ethnology, Obesity complications, Cardiovascular Diseases epidemiology, Cardiovascular Diseases ethnology, Hypertension epidemiology, Hypertension ethnology, Epidemiologic Studies, Adiposity physiology, Diabetes Mellitus, Type 2 epidemiology, Diabetes Mellitus, Type 2 ethnology, Absorptiometry, Photon
- Abstract
Background: Type 2 diabetes, cardiovascular disease, and related cardiometabolic disturbances are increasing rapidly in the Asia-Pacific region. We investigated the contribution of excess adiposity, a key determinant of type 2 diabetes and cardiovascular risk, to unfavourable cardiometabolic profiles among Asian ethnic subgroups., Methods: The Health for Life in Singapore (HELIOS) Study is a population-based cohort comprising multiethnic Asian men and women living in Singapore, aged 30-84 years. We performed a cross-sectional analysis of data from individuals who had assessment of body composition by dual-energy x-ray absorptiometry and metabolic characterisation. In a subset of participants on no medication for type 2 diabetes, hypertension, and hypercholesterolaemia, we tested the relationship of BMI and visceral fat mass index (vFMI) with cardiometabolic phenotypes (glycaemic indices, lipid levels, and blood pressure), disease outcomes (type 2 diabetes, hypercholesterolaemia, and hypertension), and metabolic syndrome score with multivariable regression analyses., Findings: Between April 2, 2018, and Jan 28, 2022, 10 004 individuals consented to be part of the HELIOS cohort, of whom 9067 were included in the study (5404 [59·6%] female, 3663 [40·4%] male; 6224 [68·6%] Chinese, 1169 [12·9%] Malay, 1674 [18·5%] Indian; mean age 52·8 years [SD 11·8]). The prevalence of type 2 diabetes, hypercholesterolaemia, and hypertension was 8·2% (n=744), 27·2% (n=2469), and 18·0% (n=1630), respectively. Malay and Indian participants had 3-4-times higher odds of obesity and type 2 diabetes, and showed adverse metabolic and adiposity profiles, compared with Chinese participants. Excess adiposity was associated with adverse cardiometabolic health indices including type 2 diabetes (p<0·0001). However, while vFMI explained the differences in triglycerides and blood pressure between the Asian ethnic groups, increased vFMI did not explain higher glucose levels, reduced insulin sensitivity, and increased risk of type 2 diabetes among Indian participants., Interpretation: Visceral adiposity is an independent risk factor for metabolic disease in Asian populations, and accounts for a large fraction of type 2 diabetes cases in each of the ethnic groups studied. However, the variation in insulin resistance and type 2 diabetes risk between Asian subgroups is not consistently explained by adiposity, indicating an important role for additional mechanisms underlying the susceptibility to cardiometabolic disease in Asian populations., Funding: Nanyang Technological University-the Lee Kong Chian School of Medicine, National Healthcare Group, and National Medical Research Council, Singapore., Competing Interests: Declaration of interests JC receives support for attending meetings and travel from Lee Kong Chian School of Medicine Strategic Academic Initiative and National Medical Research Council Singapore Translational Research Investigator Award and President's Chair in Cardiovascular Epidemiology. JC is Programme Director for Population and Global Health Programme at Lee Kong Chian School of Medicine, and Chief Scientific Officer at Precision Health Research, Singapore. JN receives research funding from Astra Zeneca. JL participates in the advisory board of Boehringer Ingelheim and is a council member of National Council Against Drug Abuse, Singapore. BLCC receives honorarium for obesity-related presentations and participates in the advisory boards of Novo Nordisk, Abbott Nutrition, and DKSH, and all honoraria were paid to Khoo Teck Puat Hospital, Singapore. All other authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved, including those for text and data mining, AI training, and similar technologies.)
- Published
- 2024
- Full Text
- View/download PDF
19. SNO-EANO-EURACAN consensus on management of pineal parenchymal tumors.
- Author
-
Liu APY, Li BK, Vasiljevic A, Dewan MC, Tamrazi B, Ertl-Wagner B, Hansford JR, Pfaff E, Mynarek M, Ng HK, Tsang DS, Gottardo NG, Gajjar A, Bouffet E, Dufour C, Pizer B, Schiff D, Jenkinson MD, Lombardi G, Wen PY, van den Bent MJ, and Huang A
- Abstract
Pineal parenchymal tumors are rare neoplasms for which evidence-based treatment recommendations are lacking. These tumors vary in biology, clinical characteristics, and prognosis, requiring treatment that ranges from surgical resection alone to intensive multimodal antineoplastic therapy. Recently, international collaborative studies have shed light on the genomic landscape of these tumors, leading to refinement in molecular-based disease classification in the 5th edition of the World Health Organization (WHO) classification of tumors of the central nervous system. In this review, we summarize the literature on diagnostic and therapeutic approaches, and suggest pragmatic recommendations for the clinical management of patients presenting with intrinsic pineal region masses including parenchymal tumors (pineocytoma, pineal parenchymal tumor of intermediate differentiation, and pineoblastoma), pineal cyst, and papillary tumors of the pineal region., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
- Published
- 2024
- Full Text
- View/download PDF
20. First 100 Reported Cases of Supine Percutaneous Nephrolithotomy in Malaysia: An Alternative Effective and Safe Approach to Treat Renal Stones.
- Author
-
Ng HK, Loo CH, and Lim MS
- Abstract
Background: Supine percutaneous nephrolithotomy (s-PCNL) offers great benefits from urological and anaesthetic points of view. We present the first evaluation of the outcomes of s-PCNL in Malaysia. Our aim was to explore the safety and efficacy of s-PCNL., Methods: Institutional review board approval was obtained from the National Medical Research Register (NMRR ID-21002225-WLP). We retrospectively reviewed 115 patients with renal pelvis stones who underwent single renal access during s-PCNL between November 2020 and May 2023. Patients who underwent simultaneous ipsilateral or contralateral endourological procedures were included. The data were analysed to determine stone-free rates (SFR), major complication rates, blood transfusion rates, operative times and lengths of hospital stay (LOS)., Results: The SFR was higher for the single middle calyceal renal access (MCA) group than for the lower calyceal renal access (LCA) or upper calyceal renal access (UCA) groups (OR: 1.76; 95% confidence interval [CI]: 0.63, 4.92). In total, 0, 1 and 2 patients had major complications in the UCA, MCA and LCA groups, respectively ( P = 0.453). One of the 115 patients (0.9%) needed blood transfusion. Subgroup analysis revealed mean operative times of 76.3 min and 78.6 min for patients who underwent sole s-PCNL (PCNL-only group) and those who had simultaneous ipsilateral and contralateral endourological procedures (PCNL-plus group), respectively ( P = 0.786). The overall mean LOS was 2.9 days., Conclusion: s-PCNL is a safe and effective alternative treatment for renal stones. We would recommend s-PCNL for patients who require an ipsilateral/contralateral endourological procedure (URS/RIRS) because it is time-efficient. All renal accesses are safe. Single MCA is recommended for complete stone clearance., Competing Interests: Conflict of Interest: None., (© Penerbit Universiti Sains Malaysia, 2024.)
- Published
- 2024
- Full Text
- View/download PDF
21. Methylome-wide studies of six metabolic traits.
- Author
-
Smith HM, Ng HK, Moodie JE, Gadd DA, McCartney DL, Bernabeu E, Campbell A, Redmond P, Taylor A, Page D, Corley J, Harris SE, Tay D, Deary IJ, Evans KL, Robinson MR, Chambers JC, Loh M, Cox SR, Marioni RE, and Hillary RF
- Abstract
Exploring the molecular correlates of metabolic health measures may identify the shared and unique biological processes and pathways that they track. Here, we performed epigenome-wide association studies (EWASs) of six metabolic traits: body mass index (BMI), body fat percentage, waist-hip ratio (WHR), and blood-based measures of glucose, high-density lipoprotein (HDL) cholesterol, and total cholesterol. We considered blood-based DNA methylation (DNAm) from >750,000 CpG sites in over 17,000 volunteers from the Generation Scotland (GS) cohort. Linear regression analyses identified between 304 and 11,815 significant CpGs per trait at P<3.6×10
-8 , with 37 significant CpG sites across all six traits. Further, we performed a Bayesian EWAS that jointly models all CpGs simultaneously and conditionally on each other, as opposed to the marginal linear regression analyses. This identified between 3 and 27 CpGs with a posterior inclusion probability ≥ 0.95 across the six traits. Next, we used elastic net penalised regression to train epigenetic scores (EpiScores) of each trait in GS, which were then tested in the Lothian Birth Cohort 1936 (LBC1936; European ancestry) and Health for Life in Singapore (HELIOS; Indian-, Malay- and Chinese-ancestries). A maximum of 27.1% of the variance in BMI was explained by the BMI EpiScore in the subset of Malay-ancestry Singaporeans. Four metabolic EpiScores were associated with general cognitive function in LBC1936 in models adjusted for vascular risk factors (Standardised βrange : 0.08 - 0.12, PFDR < 0.05). EpiScores of metabolic health are applicable across ancestries and can reflect differences in brain health., Competing Interests: R.E.M has received a speaker fee from Illumina, is an advisor to the Epigenetic Clock Development Foundation and Optima Partners Ltd. D.A.G and D.L.M. are employed by Optima Partners Ltd in a part-time capacity. R.F.H has acted as a scientific consultant to Optima Partner Ltd and has received consultant fees from Illumina. The remaining authors declare no competing interests.- Published
- 2024
- Full Text
- View/download PDF
22. Blood-based epigenome-wide analyses of chronic low-grade inflammation across diverse population cohorts.
- Author
-
Hillary RF, Ng HK, McCartney DL, Elliott HR, Walker RM, Campbell A, Huang F, Direk K, Welsh P, Sattar N, Corley J, Hayward C, McIntosh AM, Sudlow C, Evans KL, Cox SR, Chambers JC, Loh M, Relton CL, Marioni RE, Yousefi PD, and Suderman M
- Subjects
- Humans, Male, Female, Middle Aged, Adult, Cohort Studies, Aged, Chronic Disease, Inflammation genetics, Inflammation blood, Epigenome, DNA Methylation, C-Reactive Protein analysis, C-Reactive Protein genetics, C-Reactive Protein metabolism
- Abstract
Chronic inflammation is a hallmark of age-related disease states. The effectiveness of inflammatory proteins including C-reactive protein (CRP) in assessing long-term inflammation is hindered by their phasic nature. DNA methylation (DNAm) signatures of CRP may act as more reliable markers of chronic inflammation. We show that inter-individual differences in DNAm capture 50% of the variance in circulating CRP (N = 17,936, Generation Scotland). We develop a series of DNAm predictors of CRP using state-of-the-art algorithms. An elastic-net-regression-based predictor outperformed competing methods and explained 18% of phenotypic variance in the Lothian Birth Cohort of 1936 (LBC1936) cohort, doubling that of existing DNAm predictors. DNAm predictors performed comparably in four additional test cohorts (Avon Longitudinal Study of Parents and Children, Health for Life in Singapore, Southall and Brent Revisited, and LBC1921), including for individuals of diverse genetic ancestry and different age groups. The best-performing predictor surpassed assay-measured CRP and a genetic score in its associations with 26 health outcomes. Our findings forge new avenues for assessing chronic low-grade inflammation in diverse populations., Competing Interests: Declaration of interests R.F.H. and R.E.M. act as scientific consultants for Optima Partners. R.E.M. is an advisor to the Epigenetic Clock Development Foundation. R.F.H. has received consultant fees from Illumina. P.W. reports grant income from Roche Diagnostics in relation to and outside of the submitted work, as well as grant income from AstraZeneca, Boehringer Ingelheim, and Novartis outside the submitted work and speaker fees from Novo Nordisk and Raisio outside the submitted work. N.S. has consulted for Afimmune, Amgen, AstraZeneca, Boehringer Ingelheim, Eli Lilly, Hanmi Pharmaceuticals, Merck Sharp & Dohme, Novartis, Novo Nordisk, Pfizer, and Sanofi and has received grant support paid to his university from AstraZeneca, Boehringer Ingelheim, Novartis, and Roche Diagnostics outside the submitted work., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
23. Genetic variations of penicillin-binding protein 1A: insights into the current status of amoxicillin-based regimens for Helicobacter pylori eradication in Malaysia.
- Author
-
Ng HK, Chua KH, Kee BP, Chuah KH, Por LY, and Puah SM
- Subjects
- Adult, Female, Humans, Male, Middle Aged, Bacterial Proteins genetics, Drug Resistance, Bacterial genetics, Drug Therapy, Combination, Malaysia, Microbial Sensitivity Tests, Mutation, Phylogeny, Proton Pump Inhibitors therapeutic use, Amoxicillin pharmacology, Amoxicillin therapeutic use, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Genetic Variation, Helicobacter Infections drug therapy, Helicobacter Infections microbiology, Helicobacter pylori genetics, Helicobacter pylori drug effects, Penicillin-Binding Proteins genetics
- Abstract
Introduction. Resistance towards amoxicillin in Helicobacter pylori causes significant therapeutic impasse in healthcare settings worldwide. In Malaysia, the standard H. pylori treatment regimen includes a 14-day course of high-dose proton-pump inhibitor (rabeprazole, 20 mg) with amoxicillin (1000 mg) dual therapy. Hypothesis/Gap Statement. The high eradication rate with amoxicillin-based treatment could be attributed to the primary resistance rates of amoxicillin being relatively low at 0%, however, a low rate of secondary resistance has been documented in Malaysia recently. Aim. This study aims to investigate the amino acid mutations and related genetic variants in PBP1A of H. pylori , correlating with amoxicillin resistance in the Malaysian population. Methodology. The full-length pbp1A gene was amplified via PCR from 50 genomic DNA extracted from gastric biopsy samples of H. pylori -positive treatment-naïve Malaysian patients. The sequences were then compared with reference H. pylori strain ATCC 26695 for mutation and variant detection. A phylogenetic analysis of 50 sequences along with 43 additional sequences from the NCBI database was performed. These additional sequences included both amoxicillin-resistant strains ( n =20) and amoxicillin-sensitive strains ( n =23). Results. There was a total of 21 variants of amino acids, with three of them located in or near the PBP-motif (SKN402-404). The percentages of these three variants are as follows: K403X, 2%; S405I, 2% and E406K, 16%. Based on the genetic markers identified, the resistance rate for amoxicillin in our sample remained at 0%. The phylogenetic examination suggested that H. pylori might exhibit unique conserved pbp1A sequences within the Malaysian context. Conclusions. Overall, the molecular analysis of PBP1A supported the therapeutic superiority of amoxicillin-based regimens. Therefore, it is crucial to continue monitoring the amoxicillin resistance background of H. pylori with a larger sample size to ensure the sustained effectiveness of amoxicillin-based treatments in Malaysia.
- Published
- 2024
- Full Text
- View/download PDF
24. The Molecular Landscape of Primary CNS Lymphomas (PCNSLs) in Children and Young Adults.
- Author
-
Shi ZF, Li KK, Liu AP, Chung NY, Wong SC, Chen H, Woo PY, Chan DT, Mao Y, and Ng HK
- Abstract
Pediatric brain tumors are often noted to be different from their adult counterparts in terms of molecular features. Primary CNS lymphomas (PCNSLs) are mostly found in elderly adults and are uncommon in children and teenagers. There has only been scanty information about the molecular features of PCNSLs at a young age. We examined PCNSLs in 34 young patients aged between 7 and 39 years for gene rearrangements of BCl2, BCL6, CCND1, IRF4, IGH, IGL, IGK, and MYC, homozygous deletions (HD) of CDKN2A, and HLA by FISH. Sequencing was performed using WES, panel target sequencing, or Sanger sequencing due to the small amount of available tissues. The median OS was 97.5 months and longer than that for older patients with PCNSLs. Overall, only 14 instances of gene rearrangement were found (5%), and patients with any gene rearrangement were significantly older ( p = 0.029). CDKN2A HD was associated with a shorter OS ( p < 0.001). Only 10/31 (32%) showed MYD88 mutations, which were not prognostically significant, and only three of them were L265P mutations. CARD11 mutations were found in 8/24 (33%) cases only. Immunophenotypically, the cases were predominantly GCB, in contrast to older adults (61%). In summary, we showed that molecular findings identified in the PCNSLs of the older patients were only sparingly present in pediatric and young adult patients.
- Published
- 2024
- Full Text
- View/download PDF
25. Announcing the Asian Oceanian Society of Neuropathology guidelines for Adapting Diagnostic Approaches for Practical Taxonomy in Resource-Restrained Regions (AOSNP-ADAPTR).
- Author
-
Buckland ME, Sarkar C, Santosh V, Al-Hussaini M, Park SH, Tihan T, Ng HK, and Komori T
- Subjects
- Humans, Neuropathology, Nervous System Diseases
- Published
- 2024
- Full Text
- View/download PDF
26. Non-mitotic proliferation of malignant cancer cells revealed through live-cell imaging of primary and cell-line cultures.
- Author
-
Tyagi IS, Tsui HYC, Chen S, Li X, Mat WK, Khan MA, Choy LB, Chan KA, Chan TD, Ng CS, Ng HK, Poon WS, and Xue H
- Abstract
Introduction: Anti-mitosis has been a key strategy of anti-cancer therapies, targeting at a fundamental property of cancer cells, their non-controllable proliferation due to overactive mitotic divisions. For improved anti-cancer therapies, it is important to find out whether cancer cells can proliferate independent of mitosis and become resistant to anti-mitotic agents., Results: In this study, live-cell imaging was applied to both primary-cultures of tumor cells, and immortalized cancer cell lines, to detect aberrant proliferations. Cells isolated from various malignant tumors, such as Grade-III hemangiopericytoma, atypical meningioma, and metastatic brain tumor exhibit distinct cellular behaviors, including amoeboid sequestration, tailing, tunneling, nucleic DNA leakage, as well as prokaryote-like division such as binary fission and budding-shedding, which are collectively referred to and reported as 'non-mitotic proliferation' in this study. In contrast, benign tumors including Grade-I hemangiopericytoma and meningioma were not obvious in such behaviors. Moreover, when cultured in medium free of any anti-cancer drugs, cells from a recurrent Grade-III hemangiopericytoma that had been subjected to pre-operation adjuvant chemotherapy gradually shifted from non-mitotic proliferation to abnormal mitosis in the form of daughter number variation (DNV) and endomitosis, and eventually regular mitosis. Similarly, when treated with the anti-cancer drugs Epirubicin or Cisplatin, the cancer cell lines HeLa and A549 showed a shift from regular mitosis to abnormal mitosis, and further to non-mitosis as the dominant mode of proliferation with increasing drug concentrations. Upon removal of the drugs, the cells reversed back to regular mitosis with only minor occurrences of abnormal mitosis, accompanied by increased expression of the stem cell markers ALDH1, Sox, Oct4 and Nanog., Conclusions: The present study revealed that various types of malignant, but not benign, cancer cells exhibited cellular behaviors indicative of non-mitotic proliferation such as binary fission, which was typical of prokaryotic cell division, suggesting cell level atavism. Moreover, reversible transitions through the three modes of proliferation, i.e., mitosis, abnormal mitosis and non-mitosis, were observed when anticancer drug concentrations were grossly increased inducing non-mitosis or decreased favoring mitosis. Potential clinical significance of non-mitotic proliferation in cancer drug resistance and recurrence, and its relationship with cancer stem cells are worthy of further studies., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
27. Alternative lengthening of telomeres is seen in a proportion of oligodendrogliomas and is associated with a worse prognosis.
- Author
-
Shi ZF, Li KK, Chan DT, Mao Y, and Ng HK
- Abstract
Competing Interests: The authors declare that they have no conflict of interest.
- Published
- 2024
- Full Text
- View/download PDF
28. Genome-wide DNA methylation profiling for central nervous system embryonal tumours in children: abridged secondary publication.
- Author
-
Liu APY, Chan GCF, Chung BHY, Yang W, and Ng HK
- Published
- 2024
29. Rare Pediatric Cerebellar High-Grade Gliomas Mimic Medulloblastomas Histologically and Transcriptomically and Show p53 Mutations.
- Author
-
Shi ZF, Li KK, Liu AP, Chung NY, Chow C, Chen H, Kan NA, Zhu XL, Chan DT, Mao Y, and Ng HK
- Abstract
Pediatric high-grade gliomas (HGG) of the cerebellum are rare, and only a few cases have been documented in detail in the literature. A major differential diagnosis for poorly differentiated tumors in the cerebellum in children is medulloblastoma. In this study, we described the histological and molecular features of a series of five pediatric high-grade gliomas of the cerebellum. They actually showed histological and immunohistochemical features that overlapped with those of medulloblastomas and achieved high scores in NanoString-based medulloblastoma diagnostic assay. Methylation profiling demonstrated these tumors were heterogeneous epigenetically, clustering to GBM_MID, DMG_K27, and GBM_RTKIII methylation classes. MYCN amplification was present in one case, and PDGFRA amplification in another two cases. Interestingly, target sequencing showed that all tumors carried TP53 mutations. Our results highlight that pediatric high-grade gliomas of the cerebellum can mimic medulloblastomas at histological and transcriptomic levels. Our report adds to the rare number of cases in the literature of cerebellar HGGs in children. We recommend the use of both methylation array and TP53 screening in the differential diagnoses of poorly differentiated embryonal-like tumors of the cerebellum.
- Published
- 2024
- Full Text
- View/download PDF
30. Diagnostic Accuracy and Field for Improvement of Frameless Stereotactic Brain Biopsy: A Focus on Nondiagnostic Cases.
- Author
-
He Z, Zhu CXL, Chan DTM, Cheung TCY, Ng HK, Mok VCT, and Poon WS
- Subjects
- Humans, Stereotaxic Techniques, Retrospective Studies, Biopsy methods, Neuronavigation methods, Brain diagnostic imaging, Brain pathology, Brain Neoplasms diagnosis, Brain Neoplasms surgery, Brain Neoplasms pathology
- Abstract
Background: The diagnostic accuracy of frameless stereotactic brain biopsy has been reported, but there is limited literature focusing on the reasons for nondiagnostic cases. In this study, we evaluate the diagnostic accuracy of frameless stereotactic brain biopsy, compare it with the current international standard, and review the field for improvement., Methods: This is a retrospective analysis of consecutive, prospectively collected frameless stereotactic brain biopsies from 2007 to 2020. We evaluated the diagnostic accuracy of the frameless stereotactic brain biopsies using defined criteria. The biopsy result was classified as conclusive, inconclusive, or negative, based on the pathologic, radiologic, and clinical diagnosis concordance. For inconclusive or negative results, we further evaluated the preoperative planning and postoperative imaging to review the errors. A literature review for the diagnostic accuracy of frameless stereotactic biopsy was performed for the validity of our results., Results: There were 106 patients with 109 biopsies performed from 2007 to 2020. The conclusive diagnosis was reached in 103 (94.5%) procedures. An inconclusive diagnosis was noted in four (3.7%) procedures and the biopsy was negative in two (1.9%) procedures. Symptomatic hemorrhage occurred in one patient (0.9%). There was no mortality in our series. Registration error (RE) and inaccurate targeting occurred in three trigonal lesions (2.8%), sampling of the nonrepresentative part of the lesion occurred in two cases (1.8%), and one biopsy (0.9%) for lymphoma was negative due to steroid treatment. The literature review suggested that our diagnostic accuracy was comparable with the published literature., Conclusion: The frameless stereotactic biopsy is a safe procedure with high diagnostic accuracy only if meticulous preoperative planning and careful intraoperative registration is performed. The common pitfalls precluding a conclusive diagnosis are RE and biopsies at nonrepresentative sites., Competing Interests: None declared., (Thieme. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
31. Genome-Wide DNA Methylation Profiling as Frontline Diagnostics for Central Nervous System Embryonal Tumors in Hong Kong.
- Author
-
Tam OCH, Ho RSL, Chan S, Li KKW, Lam TL, Cheung ETY, Cheung OY, Ho WWS, Cheng KKF, Shing MMK, Ku DTL, Chung BHY, Yang W, Chan GCF, Ng HK, and Liu APY
- Abstract
This paper examines the link between CNS tumor biology and heterogeneity and the use of genome-wide DNA methylation profiling as a clinical diagnostic platform. CNS tumors are the most common solid tumors in children, and their prognosis remains poor. This study retrospectively analyzed pediatric patients with CNS embryonal tumors in Hong Kong between 1999 and 2017, using data from the territory-wide registry and available formalin-fixed paraffin-embedded tumor tissue. After processing archival tumor tissue via DNA extraction, quantification, and methylation profiling, the data were analyzed by using the web-based DKFZ classifier (Molecular Neuropathology (MNP) 2.0 v11b4) and t-SNE analysis. Methylation profiles were deemed informative in 85 samples. Epigenetic data allowed molecular subgrouping and confirmed diagnosis in 65 samples, verified histologic diagnosis in 8, and suggested an alternative diagnosis in 12. This study demonstrates the potential of DNA methylation profiling in characterizing pediatric CNS embryonal tumors in a large cohort from Hong Kong, which should enable regional and international collaboration in future pediatric neuro-oncology research.
- Published
- 2023
- Full Text
- View/download PDF
32. Identifying predictors of glioma evolution from longitudinal sequencing.
- Author
-
Mu Q, Chai R, Pang B, Yang Y, Liu H, Zhao Z, Bao Z, Song D, Zhu Z, Yan M, Jiang B, Mo Z, Tang J, Sa JK, Cho HJ, Chang Y, Chan KHY, Loi DSC, Tam SST, Chan AKY, Wu AR, Liu Z, Poon WS, Ng HK, Chan DTM, Iavarone A, Nam DH, Jiang T, and Wang J
- Subjects
- Adult, Humans, Temozolomide pharmacology, Temozolomide therapeutic use, Mutation genetics, Precision Medicine, Neoplasm Recurrence, Local drug therapy, Brain Neoplasms therapy, Glioma drug therapy
- Abstract
Clonal evolution drives cancer progression and therapeutic resistance. Recent studies have revealed divergent longitudinal trajectories in gliomas, but early molecular features steering posttreatment cancer evolution remain unclear. Here, we collected sequencing and clinical data of initial-recurrent tumor pairs from 544 adult diffuse gliomas and performed multivariate analysis to identify early molecular predictors of tumor evolution in three diffuse glioma subtypes. We found that CDKN2A deletion at initial diagnosis preceded tumor necrosis and microvascular proliferation that occur at later stages of IDH-mutant glioma. Ki67 expression at diagnosis was positively correlated with acquiring hypermutation at recurrence in the IDH-wild-type glioma. In all glioma subtypes, MYC gain or MYC- target activation at diagnosis was associated with treatment-induced hypermutation at recurrence. To predict glioma evolution, we constructed CELLO2 (Cancer EvoLution for LOngitudinal data version 2), a machine learning model integrating features at diagnosis to forecast hypermutation and progression after treatment. CELLO2 successfully stratified patients into subgroups with distinct prognoses and identified a high-risk patient group featured by MYC gain with worse post-progression survival, from the low-grade IDH-mutant-noncodel subtype. We then performed chronic temozolomide-induction experiments in glioma cell lines and isogenic patient-derived gliomaspheres and demonstrated that MYC drives temozolomide resistance by promoting hypermutation. Mechanistically, we demonstrated that, by binding to open chromatin and transcriptionally active genomic regions, c-MYC increases the vulnerability of key mismatch repair genes to treatment-induced mutagenesis, thus triggering hypermutation. This study reveals early predictors of cancer evolution under therapy and provides a resource for precision oncology targeting cancer dynamics in diffuse gliomas.
- Published
- 2023
- Full Text
- View/download PDF
33. Investigating causal relationships between obesity and skin barrier function in a multi-ethnic Asian general population cohort.
- Author
-
Yew YW, Mina T, Ng HK, Lam BCC, Riboli E, Lee ES, Lee J, Ngeow J, Elliott P, Thng STG, Chambers JC, and Loh M
- Subjects
- Humans, Causality, Risk Factors, Asian People, Obesity complications, Obesity epidemiology, Water Loss, Insensible, Skin Physiological Phenomena
- Abstract
Background: Skin diseases impact significantly on the quality of life and psychology of patients. Obesity has been observed as a risk factor for skin diseases. Skin epidermal barrier dysfunctions are typical manifestations across several dermatological disturbances., Objectives: We aim to establish the association between obesity and skin physiology measurements and investigate whether obesity may play a possible causal role on skin barrier dysfunction., Methods: We investigated the relationship of obesity with skin physiology measurements, namely transepidermal water loss (TEWL), skin surface moisture and skin pH in an Asian population cohort (n = 9990). To assess for a possible causal association between body mass index (BMI) and skin physiology measurements, we performed Mendelian Randomization (MR), along with subsequent additional analyses to assess the potential causal impact of known socioeconomic and comorbidities of obesity on TEWL., Results: Every 1 kg/m2 increase in BMI was associated with a 0.221% (95%CI: 0.144-0.298) increase in TEWL (P = 2.82E-08), a 0.336% (95%CI: 0.148-0.524) decrease in skin moisture (P = 4.66E-04) and a 0.184% (95%CI: 0.144-0.224) decrease in pH (P = 1.36E-19), adjusting for age, gender, and ethnicity. Relationships for both TEWL and pH with BMI remained strong (Beta 0.354; 95%CI: 0.189-0.520 and Beta -0.170; 95%CI: -0.253 to -0.087, respectively) even after adjusting for known confounders, with MR experiments further supporting BMI's possible causal relationship with TEWL. Based on additional MR performed, none of the socioeconomic and comorbidities of obesity investigated are likely to have possible causal relationships with TEWL., Conclusion: We establish strong association of BMI with TEWL and skin pH, with MR results suggestive of a possible causal relationship of obesity with TEWL. It emphasizes the potential impact of obesity on skin barrier function and therefore opportunity for primary prevention., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
34. Comparative Transcriptomic Profiling of Pellicle and Planktonic Cells from Carbapenem-Resistant Acinetobacter baumannii .
- Author
-
Ng HK, Puah SM, Teh CSJ, Idris N, and Chua KH
- Abstract
Acinetobacter baumannii forms air-liquid interface pellicles that boost its ability to withstand desiccation and increase survival under antibiotic pressure. This study aims to delve into the transcriptomic profiles of pellicle cells from clinical strains of carbapenem-resistant A. baumannii (CRAB). The total RNA was extracted from pellicle cells from three pellicle-forming CRAB strains and planktonic cells from three non-pellicle-forming CRAB strains, subject to RNA sequencing using Illumina HiSeq 2500 system. A transcriptomic analysis between pellicle and planktonic cells, along with differential expression genes (DEGs) analysis and enrichment analysis of annotated COGs, GOs, and KEGGs, was performed. Our analysis identified 366 DEGs in pellicle cells: 162 upregulated genes and 204 downregulated genes. The upregulated ABUW_1624 ( yiaY ) gene and downregulated ABUW_1550 gene indicated potential involvement in fatty acid degradation during pellicle formation. Another upregulated ABUW_2820 ( metQ ) gene, encoding the D-methionine transporter system, hinted at its contribution to pellicle formation. The upregulation of two-component systems, CusSR and KdpDE, which implies the regulation of copper and potassium ions in a CRAB pellicle formation was also observed. These findings provide valuable insights into the regulation of gene expression during the formation of pellicles in CRAB, and these are potential targets that may aid in the eradication of CRAB infections.
- Published
- 2023
- Full Text
- View/download PDF
35. Characterisation of pellicle-forming ability in clinical carbapenem-resistant Acinetobacter baumannii .
- Author
-
Ng HK, Puah SM, Teh CSJ, Idris N, and Chua KH
- Subjects
- Humans, beta-Lactamases genetics, Microbial Sensitivity Tests, Carbapenems pharmacology, Bacterial Proteins genetics, Acinetobacter baumannii genetics
- Abstract
Background: Acinetobacter baumannii was reported to have resistance towards carbapenems and the ability to form an air-liquid biofilm (pellicle) which contributes to their virulence. The GacSA two-component system has been previously shown to play a role in pellicle formation. Therefore, this study aims to detect the presence of gacA and gacS genes in carbapenem-resistant Acinetobacter baumannii (CRAB) isolates recovered from patients in intensive care units and to investigate their pellicle forming ability., Methods: The gacS and gacA genes were screened in 96 clinical CRAB isolates using PCR assay. Pellicle formation assay was performed in Mueller Hinton medium and Luria Bertani medium using borosilicate glass tubes and polypropylene plastic tubes. The biomass of the pellicle was quantitated using the crystal violet staining assay. The selected isolates were further assessed for their motility using semi-solid agar and monitored in real-time using real-time cell analyser (RTCA)., Results: All 96 clinical CRAB isolates carried the gacS and gacA genes, however, only four isolates (AB21, AB34, AB69 and AB97) displayed the ability of pellicle-formation phenotypically. These four pellicle-forming isolates produced robust pellicles in Mueller Hinton medium with better performance in borosilicate glass tubes in which biomass with OD
570 ranging from 1.984 ± 0.383 to 2.272 ± 0.376 was recorded. The decrease in cell index starting from 13 hours obtained from the impedance-based RTCA showed that pellicle-forming isolates had entered the growth stage of pellicle development., Conclusion: These four pellicle-forming clinical CRAB isolates could be potentially more virulent, therefore further investigation is warranted to provide insights into their pathogenic mechanisms., Competing Interests: Cindy Shuan Ju Teh is an Academic Editor for PeerJ., (©2023 Ng et al.)- Published
- 2023
- Full Text
- View/download PDF
36. Molecular landscapes of longitudinal NF2/22q and non-NF2/22q meningiomas show different life histories.
- Author
-
Ng HK, Li KK, Chung NY, Chan JY, Poon MF, Wong QH, Kwan JS, Poon WS, Chen H, Chan DT, Shi ZF, and Mao Y
- Subjects
- Humans, Homozygote, Phylogeny, Chromosome Deletion, Chromosome Aberrations, Meningioma genetics, Meningioma pathology, Meningeal Neoplasms genetics, Meningeal Neoplasms pathology
- Abstract
Recurrence is a major complication of some meningiomas. Although there were many studies on biomarkers associated with higher grades or increased aggressiveness, few studies specifically examined longitudinal samples of primary meningiomas and recurrences from the same patients for molecular life history. We studied 99 primary and recurrent meningiomas from 42 patients by FISH for 22q, 1q, 1p, 3p, 5q, 6q, 10p, 10q, 14q, 18q, CDKN2A/B homozygous deletion, ALT (Alternative Lengthening of Telomere), TERT re-arrangement, targeted sequencing and TERTp sequencing. Although NF2 mutation and 22q were well known to be aetiological events in meningiomas, we found that in these paired meningiomas, combining the two events resulted in an NF2/22q group (57 tumors from 25 patients) which were almost mutually exclusive with those cases without these two changes (42 tumors from 17 patients) for NF2/22q. No other molecular changes were totally unique to NF2/22q or non-NF2/22q tumors. For molecular evolution, NF2/22q meningiomas had higher cytogenetic abnormalities than non-NF2/22q meningiomas (p = 0.003). Most of the cytogenetic changes in NF2/22q meningiomas were present from the outset whereas for non-NF2/22q meningiomas, cytogenetic events were uncommon in the primary tumors and most were acquired in recurrences. For non-NF2/22q tumors, CDKN2A/B homozygous deletion, 1q gain, 18p loss, 3p loss, and ALT were preferentially found in recurrences. Mutations were largely conserved between primary and recurrent tumors. Phylogenetic trees showed 11/11 patients with multiple recurrent tumors had a conserved evolutionary pattern. We conclude that for molecular life history, NF2 and 22q should be regarded as a group. NF2/22q recurring meningiomas showed more cytogenetic abnormalities in the primary tumors, whereas non-NF2/22q meningiomas showed CDKN2A/B deletion and other cytogenetic abnormalities and ALT at recurrences. Although chromosome 1p loss is a known poor prognostic marker in meningiomas, it was also associated with a shorter TBR (time between resection) in this cohort (p = 0.002)., (© 2022 The Authors. Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology.)
- Published
- 2023
- Full Text
- View/download PDF
37. Glioneuronal tumor with ATRX alteration, kinase fusion and anaplastic features (GTAKA): a molecularly distinct brain tumor type with recurrent NTRK gene fusions.
- Author
-
Bogumil H, Sill M, Schrimpf D, Ismer B, Blume C, Rahmanzade R, Hinz F, Cherkezov A, Banan R, Friedel D, Reuss DE, Selt F, Ecker J, Milde T, Pajtler KW, Schittenhelm J, Hench J, Frank S, Boldt HB, Kristensen BW, Scheie D, Melchior LC, Olesen V, Sehested A, Boué DR, Abdullaev Z, Satgunaseelan L, Kurth I, Seidlitz A, White CL, Ng HK, Shi ZF, Haberler C, Deckert M, Timmer M, Goldbrunner R, Tauziède-Espariat A, Varlet P, Brandner S, Alexandrescu S, Snuderl M, Aldape K, Korshunov A, Witt O, Herold-Mende C, Unterberg A, Wick W, Pfister SM, von Deimling A, Jones DTW, Sahm F, and Sievers P
- Subjects
- Humans, Young Adult, Biomarkers, Tumor genetics, Brain pathology, Gene Fusion, Receptor Protein-Tyrosine Kinases genetics, X-linked Nuclear Protein genetics, Brain Neoplasms genetics, Brain Neoplasms pathology, Central Nervous System Neoplasms, Neoplasms, Neuroepithelial genetics, Neoplasms, Neuroepithelial pathology
- Abstract
Glioneuronal tumors are a heterogenous group of CNS neoplasms that can be challenging to accurately diagnose. Molecular methods are highly useful in classifying these tumors-distinguishing precise classes from their histological mimics and identifying previously unrecognized types of tumors. Using an unsupervised visualization approach of DNA methylation data, we identified a novel group of tumors (n = 20) that formed a cluster separate from all established CNS tumor types. Molecular analyses revealed ATRX alterations (in 16/16 cases by DNA sequencing and/or immunohistochemistry) as well as potentially targetable gene fusions involving receptor tyrosine-kinases (RTK; mostly NTRK1-3) in all of these tumors (16/16; 100%). In addition, copy number profiling showed homozygous deletions of CDKN2A/B in 55% of cases. Histological and immunohistochemical investigations revealed glioneuronal tumors with isomorphic, round and often condensed nuclei, perinuclear clearing, high mitotic activity and microvascular proliferation. Tumors were mainly located supratentorially (84%) and occurred in patients with a median age of 19 years. Survival data were limited (n = 18) but point towards a more aggressive biology as compared to other glioneuronal tumors (median progression-free survival 12.5 months). Given their molecular characteristics in addition to anaplastic features, we suggest the term glioneuronal tumor with ATRX alteration, kinase fusion and anaplastic features (GTAKA) to describe these tumors. In summary, our findings highlight a novel type of glioneuronal tumor driven by different RTK fusions accompanied by recurrent alterations in ATRX and homozygous deletions of CDKN2A/B. Targeted approaches such as NTRK inhibition might represent a therapeutic option for patients suffering from these tumors., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
38. Homogeneous in-plane WSe 2 P-N junctions for advanced optoelectronic devices.
- Author
-
Yue D, Ju X, Hu T, Rong X, Liu X, Liu X, Ng HK, Chi D, Wang X, and Wu J
- Abstract
Conventional doping schemes of silicon (Si) microelectronics are incompatible with atomically thick two-dimensional (2D) transition metal dichalcogenides (TMDCs), which makes it challenging to construct high-quality 2D homogeneous p-n junctions. Herein, we adopt a simple yet effective plasma-treated doping method to seamlessly construct a lateral 2D WSe
2 p-n homojunction. WSe2 with ambipolar transport properties was exposed to O2 plasma to form WOx on the surface in a self-limiting process that induces hole doping in the underlying WSe2 via electron transfer. Different electrical behaviors were observed between the as-exfoliated (ambipolar) region and the O2 plasma-treated (p-doped) region under electrostatic modulation of the back-gate bias ( VBG ), which produces a p-n in-plane homojunction. More importantly, a small contact resistance of 710 Ω μm with a p-doped region transistor mobility of ∼157 cm2 V-1 s-1 was achieved due to the transformation of Schottky contact into Ohmic contact after plasma treatment. This effectively avoids Fermi-level pinning and significantly improves the performance of photodetectors. The resultant WSe2 p-n junction device thus exhibits a high photoresponsivity of ∼7.1 × 104 mA W-1 and a superior external quantum efficiency of ∼228%. Also, the physical mechanism of charge transfer in the WSe2 p-n homojunction was analyzed. Our proposed strategy offers a powerful route to realize low contact resistance and high photoresponsivity in 2D TMDC-based optoelectronic devices, paving the way for next-generation atomic-thickness optoelectronics.- Published
- 2023
- Full Text
- View/download PDF
39. Adiposity impacts cognitive function in Asian populations: an epidemiological and Mendelian Randomization study.
- Author
-
Mina T, Yew YW, Ng HK, Sadhu N, Wansaicheong G, Dalan R, Low DYW, Lam BCC, Riboli E, Lee ES, Ngeow J, Elliott P, Griva K, Loh M, Lee J, and Chambers J
- Abstract
Background: Obesity and related metabolic disturbances including diabetes, hypertension and hyperlipidemia predict future cognitive decline. Asia has a high prevalence of both obesity and metabolic disease, potentially amplifying the future burden of dementia in the region. We aimed to investigate the impact of adiposity and metabolic risk on cognitive function in Asian populations, using an epidemiological analysis and a two-sample Mendelian Randomization (MR) study., Methods: The Health for Life in Singapore (HELIOS) Study is a population-based cohort of South-East-Asian men and women in Singapore, aged 30-84 years. We analyzed 8769 participants with metabolic and cognitive data collected between 2018 and 2021. Whole-body fat mass was quantified with Dual X-Ray Absorptiometry (DEXA). Cognition was assessed using a computerized cognitive battery. An index of general cognition ' g ' was derived through factor analysis. We tested the relationship of fat mass indices and metabolic measures with ' g ' using regression approaches. We then performed inverse-variance-weighted MR of adiposity and metabolic risk factors on ' g ', using summary statistics for genome-wide association studies of BMI, visceral adipose tissue (VAT), waist-hip-ratio (WHR), blood pressure, HDL cholesterol, triglycerides, fasting glucose, HbA1c, and general cognition., Findings: Participants were 58.9% female, and aged 51.4 (11.3) years. In univariate analysis, all 29 adiposity and metabolic measures assessed were associated with ' g ' at P < 0.05. In multivariable analyses, reduced ' g ' was consistently associated with increased visceral fat mass index and lower HDL cholesterol (P < 0.001), but not with blood pressure, triglycerides, or glycemic indices. The reduction in ' g ' associated with 1SD higher visceral fat, or 1SD lower HDL cholesterol, was equivalent to a 0.7 and 0.9-year increase in chronological age respectively (P < 0.001). Inverse variance MR analyses showed that reduced ' g ' is associated with genetically determined elevation of VAT, BMI and WHR (all P < 0.001). In contrast, MR did not support a causal role for blood pressure, lipid, or glycemic indices on cognition., Interpretation: We show an independent relationship between adiposity and cognition in a multi-ethnic Asian population. MR analyses suggest that both visceral adiposity and raised BMI are likely to be causally linked to cognition. Our findings have important implications for preservation of cognitive health, including further motivation for action to reverse the rising burden of obesity in the Asia-Pacific region., Funding: The Nanyang Technological University-the Lee Kong Chian School of Medicine, National Healthcare Group, National Medical Research Council, Ministry of Education, Singapore., Competing Interests: J.C receives support for attending meetings and travel from Lee Kong Chian School of Medicine Strategic Academic Initiative and/or National Medical Research Council Singapore Translational Research Investigator Award and/or President's Chair in Cardiovascular Epidemiology. J.C. is Programme Director for Population and Global Health Programme at Lee Kong Chian School of Medicine, and Chief Scientific Officer at Precision Health Research, Singapore. J.N. receives research and educational grant from Astra Zeneca for cancer research unrelated to this work. All other authors declare no conflict of interest., (© 2023 The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
40. scONE-seq: A single-cell multi-omics method enables simultaneous dissection of phenotype and genotype heterogeneity from frozen tumors.
- Author
-
Yu L, Wang X, Mu Q, Tam SST, Loi DSC, Chan AKY, Poon WS, Ng HK, Chan DTM, Wang J, and Wu AR
- Subjects
- Humans, RNA-Seq methods, Genotype, Phenotype, Multiomics, Neoplasms genetics
- Abstract
Single-cell multi-omics can provide a unique perspective on tumor cellular heterogeneity. Most previous single-cell whole-genome RNA sequencing (scWGS-RNA-seq) methods demonstrate utility with intact cells from fresh samples. Among them, many are not applicable to frozen samples that cannot produce intact single-cell suspensions. We have developed scONE-seq, a versatile scWGS-RNA-seq method that amplifies single-cell DNA and RNA without separating them from each other and hence is compatible with frozen biobanked samples. We benchmarked scONE-seq against existing methods using fresh and frozen samples to demonstrate its performance in various aspects. We identified a unique transcriptionally normal-like tumor clone by analyzing a 2-year frozen astrocytoma sample, demonstrating that performing single-cell multi-omics interrogation on biobanked tissue by scONE-seq could enable previously unidentified discoveries in tumor biology.
- Published
- 2023
- Full Text
- View/download PDF
41. Freehand transperineal prostate biopsy with a coaxial needle under local anesthesia: Experience from a single institution in Malaysia.
- Author
-
Ngu IS, Ngooi MS, Ng HK, Tee KTL, Loo CH, and Lim MS
- Abstract
Background: Freehand transperineal prostate biopsy (TPPBx) using a coaxial needle technique offers an alternative to probe-mounted freehand or template-guided techniques in the diagnosis of prostate cancer (PCa). It only requires the same equipment used for transrectal ultrasound-guided (TRUS) biopsy. Our study is the first in Malaysia to report this experience and its outcomes. We aim to determine PCa detection rate and pain tolerability of freehand TPPBx utilizing a coaxial needle under local anesthesia (LA)., Methods: Institutional review board approval was obtained from National Medical Research Register (NMRR ID-21-02052-VIL). We retrospectively reviewed the medical records of patients who underwent TPPBx between August 2020 and April 2022. Records were reviewed for patients' characteristics, prostate volume, prostate-specific antigen (PSA) results, biopsy results and pain tolerability. Data was analyzed to determine PCa and clinically significant prostate cancer (csPCa) detection rate. LA was achieved using perineal skin infiltration and a periprostatic nerve block. The commonly used standard side-firing transrectal ultrasound with its Prostate Biplane Transducer was used as an imaging guide. The principles of the Ginsburg protocol were followed. Pain tolerability was assessed using a visual analog scale., Results: A total of 55 patients with elevated PSA levels underwent freehand TPPBx under LA. The mean age was 67.3 years, the median PSA was 14.2 ng/mL, and the median PSA density (PSAD) was 0.33 ng/mL/cc. The optimal PSAD cutoff for predicting csPCa was 0.35 ng/mL/cc (area under the curve [AUC], 0.792; sensitivity, 87.5%; specificity, 69.2%). PCa was detected in 24 patients (43.6%), of whom 16 (29.1%) had csPCa. The median pain scores during LA infiltration and biopsy were four and two, respectively, which were significant different ( P < 0.05). TPPBx exhibited an infection rate of zero., Conclusion: The PCa detection rate and patient tolerability of freehand TPPBx using a coaxial needle are similar to those of a contemporary published series. The use of existing equipment that is used for TRUS biopsy allows for widespread use and transition from TRUS biopsy., Competing Interests: None., (© 2022 The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
42. Author Correction: Failure of human rhombic lip differentiation underlies medulloblastoma formation.
- Author
-
Hendrikse LD, Haldipur P, Saulnier O, Millman J, Sjoboen AH, Erickson AW, Ong W, Gordon V, Coudière-Morrison L, Mercier AL, Shokouhian M, Suárez RA, Ly M, Borlase S, Scott DS, Vladoiu MC, Farooq H, Sirbu O, Nakashima T, Nambu S, Funakoshi Y, Bahcheli A, Diaz-Mejia JJ, Golser J, Bach K, Phuong-Bao T, Skowron P, Wang EY, Kumar SA, Balin P, Visvanathan A, Lee JJY, Ayoub R, Chen X, Chen X, Mungall KL, Luu B, Bérubé P, Wang YC, Pfister SM, Kim SK, Delattre O, Bourdeaut F, Doz F, Masliah-Planchon J, Grajkowska WA, Loukides J, Dirks P, Fèvre-Montange M, Jouvet A, French PJ, Kros JM, Zitterbart K, Bailey SD, Eberhart CG, Rao AAN, Giannini C, Olson JM, Garami M, Hauser P, Phillips JJ, Ra YS, de Torres C, Mora J, Li KKW, Ng HK, Poon WS, Pollack IF, López-Aguilar E, Gillespie GY, Van Meter TE, Shofuda T, Vibhakar R, Thompson RC, Cooper MK, Rubin JB, Kumabe T, Jung S, Lach B, Iolascon A, Ferrucci V, de Antonellis P, Zollo M, Cinalli G, Robinson S, Stearns DS, Van Meir EG, Porrati P, Finocchiaro G, Massimino M, Carlotti CG, Faria CC, Roussel MF, Boop F, Chan JA, Aldinger KA, Razavi F, Silvestri E, McLendon RE, Thompson EM, Ansari M, Garre ML, Chico F, Eguía P, Pérezpeña M, Morrissy AS, Cavalli FMG, Wu X, Daniels C, Rich JN, Jones SJM, Moore RA, Marra MA, Huang X, Reimand J, Sorensen PH, Wechsler-Reya RJ, Weiss WA, Pugh TJ, Garzia L, Kleinman CL, Stein LD, Jabado N, Malkin D, Ayrault O, Golden JA, Ellison DW, Doble B, Ramaswamy V, Werbowetski-Ogilvie TE, Suzuki H, Millen KJ, and Taylor MD
- Published
- 2022
- Full Text
- View/download PDF
43. Molecular landscape of IDH-wild type, pTERT-wild type adult glioblastomas.
- Author
-
Liu EM, Shi ZF, Li KK, Malta TM, Chung NY, Chen H, Chan JY, Poon MF, Kwan JS, Chan DT, Noushmehr H, Mao Y, and Ng HK
- Subjects
- Humans, Isocitrate Dehydrogenase genetics, Homozygote, In Situ Hybridization, Fluorescence, Sequence Deletion, Mutation genetics, ErbB Receptors genetics, Biomarkers, Prognosis, Glioblastoma genetics, Glioblastoma pathology, Brain Neoplasms pathology, Telomerase genetics
- Abstract
Telomerase reverse transcriptase (TERT) promoter (pTERT) mutation has often been described as a late event in gliomagenesis and it has been suggested as a prognostic biomarker in gliomas other than 1p19q codeleted tumors. However, the characteristics of isocitrate dehydrogenase (IDH) wild type (wt) (IDHwt), pTERTwt glioblastomas are not well known. We recruited 72 adult IDHwt, pTERTwt glioblastomas and performed methylation profiling, targeted sequencing, and fluorescence in situ hybridization (FISH) for TERT structural rearrangement and ALT (alternative lengthening of telomeres). There was no significant difference in overall survival (OS) between our cohort and a the Cancer Genome Atlas (TCGA) cohort of IDHwt, pTERT mutant (mut) glioblastomas, suggesting that pTERT mutation on its own is not a prognostic factor among IDHwt glioblastomas. Epigenetically, the tumors clustered into classic-like (11%), mesenchymal-like (32%), and LGm6-glioblastoma (GBM) (57%), the latter far exceeding the corresponding proportion seen in the TCGA cohort of IDHwt, pTERTmut glioblastomas. LGm6-GBM-clustered tumors were enriched for platelet derived growth factor receptor alpha (PDGFRA) amplification or mutation (p = 0.008), and contained far fewer epidermal growth factor receptor (EGFR) amplification (p < 0.01), 10p loss (p = 0.001) and 10q loss (p < 0.001) compared with cases not clustered to this group. LGm6-GBM cases predominantly showed ALT (p = 0.038). In the whole cohort, only 35% cases showed EGFR amplification and no case showed combined chromosome +7/-10. Since the cases were already pTERTwt, so the three molecular properties of EGFR amplification, +7/-10, and pTERT mutation may not cover all IDHwt glioblastomas. Instead, EGFR and PDGFRA amplifications covered 67% and together with their mutations covered 71% of cases of this cohort. Homozygous deletion of cyclin dependent kinase inhibitor 2A (CDKN2A)/B was associated with a worse OS (p = 0.031) and was an independent prognosticator in multivariate analysis (p = 0.032). In conclusion, adult IDHwt, pTERTwt glioblastomas show epigenetic clustering different from IDHwt, pTERTmut glioblastomas, and IDHwt glioblastomas which are pTERTwt may however not show EGFR amplification or +7/-10 in a significant proportion of cases. CDKN2A/B deletion is a poor prognostic biomarker in this group., (© 2022 The Authors. Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology.)
- Published
- 2022
- Full Text
- View/download PDF
44. PRAME immunostain expression in sebaceous lesions, cutaneous carcinomas and adnexal structures.
- Author
-
Ng JKM, Choi PCL, Chow C, Li JJX, Chan AWS, Cheung CMT, Ip ECC, Ng HK, and To KF
- Subjects
- Antigens, Neoplasm, Humans, Sebaceous Glands pathology, Skin pathology, Carcinoma, Basal Cell diagnosis, Carcinoma, Basal Cell metabolism, Carcinoma, Squamous Cell pathology, Neoplasms, Adnexal and Skin Appendage diagnosis, Neoplasms, Adnexal and Skin Appendage pathology, Sebaceous Gland Neoplasms diagnosis, Skin Neoplasms diagnosis, Skin Neoplasms metabolism
- Abstract
The use of immunostain for PRAME antigen is well established for cutaneous melanolocytic lesions. However, its staining in other cutaneous structures and lesions is under reported. This study assessed PRAME staining in a large cohort of normal skin tissue, sebaceous lesions, and cutaneous carcinomas to better delineate patterns of PRAME immunoreactivity. PRAME immunostaining was performed on sections of sebaceous lesions and tissue microarrays of basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs). Normal cutaneous adnexal structures were assessed on the sections of sebaceous lesions. For sebaceous lesions and non-lesional sebaceous glands, PRAME immunostaining was assessed for mature, germinative and sebocytes independently. A total of 193 sebaceous lesions, 64 BCCs and 35 SCCs were stained for PRAME immunostain. Staining pattern was predominantly cytoplasmic in normal apocrine glands, germinative sebocytes of sebaceous glands, and hair germs (p<0.001). Lesional sebocytes did not show different staining compared to normal sebaceous glands (p>0.05). Rare nuclear staining was observed in the normal epidermis (0.6%) and junctional melanocytes (4.1%). BCC, SCC and sebaceous carcinoma all showed low levels of PRAME immunoreactivity with variable proportions of cases demonstrating nuclear staining (BCC 59.4%, SCC 37.1%, sebaceous carcinoma 5.3%). PRAME immunostaining is positive in germinative sebocytes, various cutaneous structures and carcinomas. Nuclear staining, identical to melanoma, was observed in normal epidermis, junctional melanocytes, BCCs, SCCs, and sebaceous carcinomas. The pattern of PRAME staining in the skin must be recognised to avoid pitfalls in interpretating PRAME immunostain., (Copyright © 2022 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
45. Patterns of care and survival of Chinese glioblastoma patients in the temozolomide era: a Hong Kong population-level analysis over a 14-year period.
- Author
-
Woo PYM, Yau S, Lam TC, Pu JKS, Li LF, Lui LCY, Chan DTM, Loong HHF, Lee MWY, Yeung R, Kwok CCH, Au SK, Tan TC, Kan ANC, Chan TKT, Mak CHK, Mak HKF, Ho JMK, Cheung KM, Tse TPK, Lau SSN, Chow JSW, El-Helali A, Ng HK, and Poon WS
- Abstract
Background: The aim of this study is to address the paucity of epidemiological data regarding the characteristics, treatment patterns and survival outcomes of Chinese glioblastoma patients., Methods: This was a population-level study of Hong Kong adult ( > 18 years) Chinese patients with newly diagnosed histologically confirmed glioblastoma between 2006 and 2019. The age standardized incidence rate (ASIR), patient-, tumor- treatment-related characteristics, overall survival (OS) as well as its predictors were determined., Results: One thousand and ten patients with a median follow-up of 10.0 months were reviewed. The ASIR of glioblastoma was 1.0 per 100 000 population with no significant change during the study period. The mean age was 57 + 14 years. The median OS was 10.6 months (IQR: 5.2-18.4). Independent predictors for survival were: Karnofsky performance score > 80 (adjusted OR: 0.8; 95% CI: 0.6-0.9), IDH-1 mutant (aOR: 0.7; 95% CI: 0.5-0.9) or MGMT methylated (aOR: 0.7; 95% CI: 0.5-0.8) glioblastomas, gross total resection (aOR: 0.8; 95% CI: 0.5-0.8) and temozolomide chemoradiotherapy (aOR 0.4; 95% CI: 0.3-0.6). Despite the significant increased administration of temozolomide chemoradiotherapy from 39% (127/326) of patients in 2006-2010 to 63% (227/356) in 2015-2019 ( P -value < .001), median OS did not improve (2006-2010: 10.3 months vs 2015-2019: 11.8 months) (OR: 1.1; 95% CI: 0.9-1.3)., Conclusions: The incidence of glioblastoma in the Chinese general population is low. We charted the development of neuro-oncological care of glioblastoma patients in Hong Kong during the temozolomide era. Although there was an increased adoption of temozolomide chemoradiotherapy, a corresponding improvement in survival was not observed., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Neuro-Oncology and the European Association of Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2022
- Full Text
- View/download PDF
46. Antibody stabilization for thermally accelerated deep immunostaining.
- Author
-
Lai HM, Tang Y, Lau ZYH, Campbell RAA, Yau JCN, Chan CCY, Chan DCW, Wong TY, Wong HKT, Yan LYC, Wu WKK, Wong SH, Kwok KW, Wing YK, Lam HHN, Ng HK, Mrsic-Flogel TD, Mok VCT, Chan JYK, and Ko H
- Subjects
- Animals, Humans, Mice, Antibodies metabolism, Brain metabolism
- Abstract
Antibodies have diverse applications due to their high reaction specificities but are sensitive to denaturation when a higher working temperature is required. We have developed a simple, highly scalable and generalizable chemical approach for stabilizing off-the-shelf antibodies against thermal and chemical denaturation. We demonstrate that the stabilized antibodies (termed SPEARs) can withstand up to 4 weeks of continuous heating at 55 °C and harsh denaturants, and apply our method to 33 tested antibodies. SPEARs enable flexible applications of thermocycling and denaturants to dynamically modulate their binding kinetics, reaction equilibrium, macromolecular diffusivity and aggregation propensity. In particular, we show that SPEARs permit the use of a thermally facilitated three-dimensional immunolabeling strategy (termed ThICK staining), achieving whole mouse brain immunolabeling within 72 h, as well as nearly fourfold deeper penetration with threefold less antibodies in human brain tissue. With faster deep-tissue immunolabeling and broad compatibility with tissue processing and clearing methods without the need for any specialized equipment, we anticipate the wide applicability of ThICK staining with SPEARs for deep immunostaining., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
47. Failure of human rhombic lip differentiation underlies medulloblastoma formation.
- Author
-
Hendrikse LD, Haldipur P, Saulnier O, Millman J, Sjoboen AH, Erickson AW, Ong W, Gordon V, Coudière-Morrison L, Mercier AL, Shokouhian M, Suárez RA, Ly M, Borlase S, Scott DS, Vladoiu MC, Farooq H, Sirbu O, Nakashima T, Nambu S, Funakoshi Y, Bahcheli A, Diaz-Mejia JJ, Golser J, Bach K, Phuong-Bao T, Skowron P, Wang EY, Kumar SA, Balin P, Visvanathan A, Lee JJY, Ayoub R, Chen X, Chen X, Mungall KL, Luu B, Bérubé P, Wang YC, Pfister SM, Kim SK, Delattre O, Bourdeaut F, Doz F, Masliah-Planchon J, Grajkowska WA, Loukides J, Dirks P, Fèvre-Montange M, Jouvet A, French PJ, Kros JM, Zitterbart K, Bailey SD, Eberhart CG, Rao AAN, Giannini C, Olson JM, Garami M, Hauser P, Phillips JJ, Ra YS, de Torres C, Mora J, Li KKW, Ng HK, Poon WS, Pollack IF, López-Aguilar E, Gillespie GY, Van Meter TE, Shofuda T, Vibhakar R, Thompson RC, Cooper MK, Rubin JB, Kumabe T, Jung S, Lach B, Iolascon A, Ferrucci V, de Antonellis P, Zollo M, Cinalli G, Robinson S, Stearns DS, Van Meir EG, Porrati P, Finocchiaro G, Massimino M, Carlotti CG, Faria CC, Roussel MF, Boop F, Chan JA, Aldinger KA, Razavi F, Silvestri E, McLendon RE, Thompson EM, Ansari M, Garre ML, Chico F, Eguía P, Pérezpeña M, Morrissy AS, Cavalli FMG, Wu X, Daniels C, Rich JN, Jones SJM, Moore RA, Marra MA, Huang X, Reimand J, Sorensen PH, Wechsler-Reya RJ, Weiss WA, Pugh TJ, Garzia L, Kleinman CL, Stein LD, Jabado N, Malkin D, Ayrault O, Golden JA, Ellison DW, Doble B, Ramaswamy V, Werbowetski-Ogilvie TE, Suzuki H, Millen KJ, and Taylor MD
- Subjects
- Cell Lineage, Cerebellum embryology, Cerebellum pathology, Core Binding Factor alpha Subunits genetics, Hedgehog Proteins metabolism, Histone Demethylases, Humans, Ki-67 Antigen metabolism, Muscle Proteins, Mutation, Otx Transcription Factors deficiency, Otx Transcription Factors genetics, Repressor Proteins, T-Box Domain Proteins metabolism, Transcription Factors, Cell Differentiation genetics, Cerebellar Neoplasms classification, Cerebellar Neoplasms genetics, Cerebellar Neoplasms pathology, Medulloblastoma classification, Medulloblastoma genetics, Medulloblastoma pathology, Metencephalon embryology, Metencephalon pathology
- Abstract
Medulloblastoma (MB) comprises a group of heterogeneous paediatric embryonal neoplasms of the hindbrain with strong links to early development of the hindbrain
1-4 . Mutations that activate Sonic hedgehog signalling lead to Sonic hedgehog MB in the upper rhombic lip (RL) granule cell lineage5-8 . By contrast, mutations that activate WNT signalling lead to WNT MB in the lower RL9,10 . However, little is known about the more commonly occurring group 4 (G4) MB, which is thought to arise in the unipolar brush cell lineage3,4 . Here we demonstrate that somatic mutations that cause G4 MB converge on the core binding factor alpha (CBFA) complex and mutually exclusive alterations that affect CBFA2T2, CBFA2T3, PRDM6, UTX and OTX2. CBFA2T2 is expressed early in the progenitor cells of the cerebellar RL subventricular zone in Homo sapiens, and G4 MB transcriptionally resembles these progenitors but are stalled in developmental time. Knockdown of OTX2 in model systems relieves this differentiation blockade, which allows MB cells to spontaneously proceed along normal developmental differentiation trajectories. The specific nature of the split human RL, which is destined to generate most of the neurons in the human brain, and its high level of susceptible EOMES+ KI67+ unipolar brush cell progenitor cells probably predisposes our species to the development of G4 MB., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)- Published
- 2022
- Full Text
- View/download PDF
48. Modulation of Spin Dynamics in 2D Transition-Metal Dichalcogenide via Strain-Driven Symmetry Breaking.
- Author
-
Liu T, Xiang D, Ng HK, Han Z, Hippalgaonkar K, Suwardi A, Martin J, Garaj S, and Wu J
- Abstract
Transition metal dichalcogenides (TMDs) possess intrinsic spin-orbit interaction (SOI) with high potential to be exploited for various quantum phenomena. SOI allows the manipulation of spin degree of freedom by controlling the carrier's orbital motion via mechanical strain. Here, strain modulated spin dynamics in bilayer MoS
2 field-effect transistors (FETs) fabricated on crested substrates are demonstrated. Weak antilocalization (WAL) is observed at moderate carrier concentrations, indicating additional spin relaxation path caused by strain fields arising from substrate crests. The spin lifetime is found to be inversely proportional to the momentum relaxation time, which follows the Dyakonov-Perel spin relaxation mechanism. Moreover, the spin-orbit splitting is obtained as 37.5 ± 1.4 meV, an order of magnitude larger than the theoretical prediction for monolayer MoS2 , suggesting the strain enhanced spin-lattice coupling. The work demonstrates strain engineering as a promising approach to manipulate spin degree of freedom toward new functional quantum devices., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)- Published
- 2022
- Full Text
- View/download PDF
49. Molecular landscape of pediatric type IDH wildtype, H3 wildtype hemispheric glioblastomas.
- Author
-
Hong L, Shi ZF, Li KK, Wang WW, Yang RR, Kwan JS, Chen H, Li FC, Liu XZ, Chan DT, Li WC, Zhang ZY, Mao Y, and Ng HK
- Subjects
- Child, ErbB Receptors genetics, Humans, Mutation, N-Myc Proto-Oncogene Protein genetics, Protein-Tyrosine Kinases genetics, Proto-Oncogene Proteins genetics, Brain Neoplasms pathology, Glioblastoma
- Abstract
The WHO (2021) Classification classified a group of pediatric-type high-grade gliomas as IDH wildtype, H3 wildtype but as of currently, they are characterized only by negative molecular features of IDH and H3. We recruited 35 cases of pediatric IDH wildtype and H3 wildtype hemispheric glioblastomas. We evaluated them with genome-wide methylation profiling, targeted sequencing, RNAseq, TERT promoter sequencing, and FISH. The median survival of the cohort was 27.6 months. With Capper et al.'s
36 methylation groups as a map, the cases were found to be epigenetically heterogeneous and were clustered in proximity or overlay of methylation groups PXA-like (n = 8), LGG-like (n = 10), GBM_MYCN (n = 9), GBM_midline (n = 5), and GBM_RTKIII (n = 3). Histology of the tumors in these groups was not different from regular glioblastomas. Methylation groups were not associated with OS. We were unable to identify groups specifically characterized by EGFR or PDGFRA amplification as proposed by other authors. EGFR, PDGFRA, and MYCN amplifications were not correlated with OS. 4/9 cases of the GBM_MYCN cluster did not show MYCN amplification; the group was also enriched for EGFR amplification (4/9 cases) and the two biomarkers overlapped in two cases. Overall, PDGFRA amplification was found in only four cases and they were not restricted to any groups. Cases in proximity to GBM_midline were all hemispheric and showed loss of H3K27me3 staining. Fusion genes ALK/NTRK/ROS1/MET characteristic of infantile glioblastomas were not identified in 17 cases successfully sequenced. BRAF V600E was only found in the PXA group but CDKN2A deletion could be found in other methylation groups. PXA-like cases did not show PXA histological features similar to findings by other authors. No case showed TERT promoter mutation. Mutations of mismatch repair (MMR) genes were poor prognosticators in single (p ≤ 0.001) but not in multivariate analyses (p = 0.229). MGMT had no survival significance in this cohort. Of the other common biomarkers, only TP53 and ATRX mutations were significant poor prognosticators and only TP53 mutation was significant after multivariate analyses (p = 0.024). We conclude that IDH wildtype, H3 wildtype pediatric hemispheric glioblastomas are molecularly heterogeneous and in routine practice, TP53, ATRX, and MMR status could profitably be screened for risk stratification in laboratories without ready access to methylation profiling., (© 2022. The Author(s), under exclusive licence to United States and Canadian Academy of Pathology.)- Published
- 2022
- Full Text
- View/download PDF
50. Molecular landscape of IDH-wild-type, H3-wild-type glioblastomas of adolescents and young adults.
- Author
-
Shi ZF, Li KK, Huang QJ, Wang WW, Kwan JS, Chen H, Liu XZ, Li WC, Chan DT, Zhang ZY, Mao Y, and Ng HK
- Subjects
- Adolescent, DNA Methylation, DNA Modification Methylases genetics, DNA Repair Enzymes genetics, Humans, Isocitrate Dehydrogenase genetics, Mutation, Proto-Oncogene Proteins B-raf genetics, Young Adult, Astrocytoma pathology, Brain Neoplasms pathology, Glioblastoma pathology
- Abstract
Objective: We aimed to characterise glioblastomas of adolescents and young adults (AYAs) that were isocitrate dehydrogenase (IDH) wild type (wt) and H3wt., Materials and Methods: Fifty such patients (aged 16-32) were studied by methylation profiling, targeted sequencing and targeted RNA-seq., Results: Tumours predominantly clustered into three methylation classes according to the terminology of Capper et al. (2018): (anaplastic) pleomorphic xanthoastrocytoma (PXA) (21 cases), GBM_midline (15 cases) and glioblastoma RTK/mesenchymal (seven cases). Two cases clustered with ANA_PA, four cases with LGG classes and one with GBM_MYCN. Only fifteen cases reached a calibrated score >0.84 when the cases were uploaded to DKFZ Classifier. GBM_midline-clustered tumours had a poorer overall survival (OS) compared with the PXA-clustered tumours (p = 0.030). LGG-clustered cases had a significantly better survival than GBM_midline-clustered tumours and glioblastoma RTK/mesenchymal-clustered tumours. Only 13/21 (62%) of PXA-clustered cases were BRAF V600E mutated. Most GBM_midline-clustered cases were not located in the midline. GBM_midline-clustered cases were characterised by PDGFRA amplification/mutation (73.3%), mutations of mismatch repair genes (40.0%), and all showed H3K27me3 and EZH1P loss, and an unmethylated MGMT promoter. Across the whole cohort, MGMT promoter methylation and wt TERT promoter were favourable prognosticators. Mismatch repair gene mutations were poor prognosticators and together with methylation class and MGMT methylation, maintained their significance in multivariate analyses. BRAF mutation was a good prognosticator in the PXA-clustered tumours., Conclusion: Methylation profiling is a useful tool in the diagnosis and prognostication of AYA glioblastomas, and the methylation classes have distinct molecular characteristics. The usual molecular diagnostic criteria for adult IDHwt glioblastoma should be applied with caution within the AYA age group., (© 2022 British Neuropathological Society.)
- Published
- 2022
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.