36 results on '"Ioannis Assiotis"'
Search Results
2. A genetic screen using the PiggyBac transposon in haploid cells identifies Parp1 as a mediator of olaparib toxicity.
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Stephen J Pettitt, Farah L Rehman, Ilirjana Bajrami, Rachel Brough, Fredrik Wallberg, Iwanka Kozarewa, Kerry Fenwick, Ioannis Assiotis, Lina Chen, James Campbell, Christopher J Lord, and Alan Ashworth
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Medicine ,Science - Abstract
Genetic perturbation screens have the potential to dissect a wide range of cellular phenotypes. Such screens have historically been difficult in diploid mammalian cells. The recent derivation of haploid embryonic stem cells provides an opportunity to cause loss of function mutants with a random mutagen in a mammalian cell with a normal genetic background. We describe an approach to genetic screens that exploits the highly active piggyBac transposon in haploid mammalian cells. As an example of haploid transposon (HTP) screening, we apply this approach to identifying determinants of cancer drug toxicity and resistance. In a screen for 6-thioguanine resistance we recovered components of the DNA mismatch repair pathway, a known requirement for toxicity. In a further screen for resistance to the clinical poly(ADP-ribose) polymerase (PARP) inhibitor olaparib we recovered multiple Parp1 mutants. Our results show that olaparib toxicity to normal cells is mediated predominantly via Parp1, and suggest that the clinical side effects of olaparib may be on target. The transposon mutant libraries are stable and can be readily reused to screen other drugs. The screening protocol described has several advantages over other methods such as RNA interference: it is rapid and low cost, and mutations can be easily reverted to establish causality.
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- 2013
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3. A modified method for whole exome resequencing from minimal amounts of starting DNA.
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Iwanka Kozarewa, Juan Manuel Rosa-Rosa, Christopher P Wardell, Brian A Walker, Kerry Fenwick, Ioannis Assiotis, Costas Mitsopoulos, Marketa Zvelebil, Gareth J Morgan, Alan Ashworth, and Christopher J Lord
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Medicine ,Science - Abstract
Next generation DNA sequencing (NGS) technologies have revolutionized the pace at which whole genome and exome sequences can be generated. However, despite these advances, many of the methods for targeted resequencing, such as the generation of high-depth exome sequences, are somewhat limited by the relatively large amounts of starting DNA that are normally required. In the case of tumour analysis this is particularly pertinent as many tumour biopsies often return submicrogram quantities of DNA, especially when tumours are microdissected prior to analysis. Here, we present a method for exome capture and resequencing using as little as 50 ng of starting DNA. The sequencing libraries generated by this minimal starting amount (MSA-Cap) method generate datasets that are comparable to standard amount (SA) whole exome libraries that use three micrograms of starting DNA. This method, which can be performed in most laboratories using commonly available reagents, has the potential to enhance large scale profiling efforts such as the resequencing of tumour exomes.
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- 2012
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4. Correction: A Modified Method for Whole Exome Resequencing from Minimal Amounts of Starting DNA.
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Iwanka Kozarewa, Juan Manuel Rosa-Rosa, Christopher P. Wardell, Brian A. Walker, Kerry Fenwick, Ioannis Assiotis, Costas Mitsopoulos, Marketa Zvelebil, Gareth J. Morgan, Alan Ashworth, and Christopher J. Lord
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Medicine ,Science - Published
- 2012
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5. Comprehensive genomic analysis of a BRCA2 deficient human pancreatic cancer.
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Louise J Barber, Juan M Rosa Rosa, Iwanka Kozarewa, Kerry Fenwick, Ioannis Assiotis, Costas Mitsopoulos, David Sims, Jarle Hakas, Marketa Zvelebil, Christopher J Lord, and Alan Ashworth
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Medicine ,Science - Abstract
Capan-1 is a well-characterised BRCA2-deficient human cell line isolated from a liver metastasis of a pancreatic adenocarcinoma. Here we report a genome-wide assessment of structural variations and high-depth exome characterization of single nucleotide variants and small insertion/deletions in Capan-1. To identify potential somatic and tumour-associated variations in the absence of a matched-normal cell line, we devised a novel method based on the analysis of HapMap samples. We demonstrate that Capan-1 has one of the most rearranged genomes sequenced to date. Furthermore, small insertions and deletions are detected more frequently in the context of short sequence repeats than in other genomes. We also identify a number of novel mutations that may represent genetic changes that have contributed to tumour progression. These data provide insight into the genomic effects of loss of BRCA2 function.
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- 2011
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6. Supplementary Table 1 from Efficacy of Chemotherapy in BRCA1/2 Mutation Carrier Ovarian Cancer in the Setting of PARP Inhibitor Resistance: A Multi-Institutional Study
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Stan B. Kaye, Alan Ashworth, Christopher J. Lord, Martin E. Gore, Johann S. de Bono, Lina Chen, James Campbell, Ioannis Assiotis, Kerry Fenwick, Iwanka Kozarewa, Louise J. Barber, Ursula Matulonis, Amit M. Oza, Bella Kaufman, Michael L. Friedlander, Lee-May Chen, Susana Banerjee, Shahneen Sandhu, Timothy A. Yap, Tina Atkinson, Jacques De Greve, Vincent Castonguay, Ronnie Shapira-Frommer, Hilda High, C. Bethan Powell, Charlie Gourley, and Joo Ern Ang
- Abstract
Supplementary Table 1 - PDF file 57K, Supplementary Table 1. Details of platinum sensitivity and best response to olaparib and post-PARPi chemotherapy of the six patients whose tumor samples were analyzed by massively parallel sequencing. (NE: not evaluable)
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- 2023
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7. Data from Efficacy of Chemotherapy in BRCA1/2 Mutation Carrier Ovarian Cancer in the Setting of PARP Inhibitor Resistance: A Multi-Institutional Study
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Stan B. Kaye, Alan Ashworth, Christopher J. Lord, Martin E. Gore, Johann S. de Bono, Lina Chen, James Campbell, Ioannis Assiotis, Kerry Fenwick, Iwanka Kozarewa, Louise J. Barber, Ursula Matulonis, Amit M. Oza, Bella Kaufman, Michael L. Friedlander, Lee-May Chen, Susana Banerjee, Shahneen Sandhu, Timothy A. Yap, Tina Atkinson, Jacques De Greve, Vincent Castonguay, Ronnie Shapira-Frommer, Hilda High, C. Bethan Powell, Charlie Gourley, and Joo Ern Ang
- Abstract
Purpose: Preclinical data suggest that exposure to PARP inhibitors (PARPi) may compromise benefit to subsequent chemotherapy, particularly platinum-based regimens, in patients with BRCA1/2 mutation carrier ovarian cancer (PBMCOC), possibly through the acquisition of secondary BRCA1/2 mutations. The efficacy of chemotherapy in the PARPi-resistant setting was therefore investigated.Experimental Design: We conducted a retrospective review of PBMCOC who received chemotherapy following disease progression on olaparib, administered at ≥200 mg twice daily for one month or more. Tumor samples were obtained in the post-olaparib setting where feasible and analyzed by massively parallel sequencing.Results: Data were collected from 89 patients who received a median of 3 (range 1–11) lines of pre-olaparib chemotherapy. The overall objective response rate (ORR) to post-olaparib chemotherapy was 36% (24 of 67 patients) by Response Evaluation Criteria in Solid Tumors (RECIST) and 45% (35 of 78) by RECIST and/or Gynecologic Cancer InterGroup (GCIG) CA125 criteria with median progression-free survival (PFS) and overall survival (OS) of 17 weeks [95% confidence interval (CI), 13–21] and 34 weeks (95% CI, 26–42), respectively. For patients receiving platinum-based chemotherapy, ORRs were 40% (19 of 48) and 49% (26/53), respectively, with a median PFS of 22 weeks (95% CI, 15–29) and OS of 45 weeks (95% CI, 15–75). An increased platinum-to-platinum interval was associated with an increased OS and likelihood of response following post-olaparib platinum. No evidence of secondary BRCA1/2 mutation was detected in tumor samples of six PARPi-resistant patients [estimated frequency of such mutations adjusted for sample size: 0.125 (95%-CI: 0–0.375)].Conclusions: Heavily pretreated PBMCOC who are PARPi-resistant retain the potential to respond to subsequent chemotherapy, including platinum-based agents. These data support the further development of PARPi in PBMCOC. Clin Cancer Res; 19(19); 5485–93. ©2013 AACR.
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- 2023
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8. Supplementary Table 2 from Genome-wide Profiling of Genetic Synthetic Lethality Identifies CDK12 as a Novel Determinant of PARP1/2 Inhibitor Sensitivity
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Alan Ashworth, Christopher J. Lord, Rachael Natrajan, Kerry Fenwick, Ioannis Assiotis, Iwanka Kozarewa, Lina Chen, Sean Hooper, Rumana Rafiq, David Sims, James Campbell, Rachel Brough, Farah L. Rehman, Rowan E. Miller, Asha Konde, Jessica R. Frankum, and Ilirjana Bajrami
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PDF file 543K, Supplementary Table S2 shRNA constructs with Olaparib Drug Effect Z scores
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- 2023
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9. Supplementary Table 1 from Genome-wide Profiling of Genetic Synthetic Lethality Identifies CDK12 as a Novel Determinant of PARP1/2 Inhibitor Sensitivity
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Alan Ashworth, Christopher J. Lord, Rachael Natrajan, Kerry Fenwick, Ioannis Assiotis, Iwanka Kozarewa, Lina Chen, Sean Hooper, Rumana Rafiq, David Sims, James Campbell, Rachel Brough, Farah L. Rehman, Rowan E. Miller, Asha Konde, Jessica R. Frankum, and Ilirjana Bajrami
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PDF file 32K, Supplementary Table S1 Antibody reagent list used in study
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- 2023
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10. Supplementary Table 4 from Genome-wide Profiling of Genetic Synthetic Lethality Identifies CDK12 as a Novel Determinant of PARP1/2 Inhibitor Sensitivity
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Alan Ashworth, Christopher J. Lord, Rachael Natrajan, Kerry Fenwick, Ioannis Assiotis, Iwanka Kozarewa, Lina Chen, Sean Hooper, Rumana Rafiq, David Sims, James Campbell, Rachel Brough, Farah L. Rehman, Rowan E. Miller, Asha Konde, Jessica R. Frankum, and Ilirjana Bajrami
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PDF file 58K, Supplementary Table S4. DNA repair involvement of PARP inhibitor sensitisation genes found in the screen. PMID numbers refer to pubmed entries
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- 2023
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11. Data from Genome-wide Profiling of Genetic Synthetic Lethality Identifies CDK12 as a Novel Determinant of PARP1/2 Inhibitor Sensitivity
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Alan Ashworth, Christopher J. Lord, Rachael Natrajan, Kerry Fenwick, Ioannis Assiotis, Iwanka Kozarewa, Lina Chen, Sean Hooper, Rumana Rafiq, David Sims, James Campbell, Rachel Brough, Farah L. Rehman, Rowan E. Miller, Asha Konde, Jessica R. Frankum, and Ilirjana Bajrami
- Abstract
Small-molecule inhibitors of PARP1/2, such as olaparib, have been proposed to serve as a synthetic lethal therapy for cancers that harbor BRCA1 or BRCA2 mutations. Indeed, in clinical trials, PARP1/2 inhibitors elicit sustained antitumor responses in patients with germline BRCA gene mutations. In hypothesizing that additional genetic determinants might direct use of these drugs, we conducted a genome-wide synthetic lethal screen for candidate olaparib sensitivity genes. In support of this hypothesis, the set of identified genes included known determinants of olaparib sensitivity, such as BRCA1, RAD51, and Fanconi's anemia susceptibility genes. In addition, the set included genes implicated in established networks of DNA repair, DNA cohesion, and chromatin remodeling, none of which were known previously to confer sensitivity to PARP1/2 inhibition. Notably, integration of the list of candidate sensitivity genes with data from tumor DNA sequencing studies identified CDK12 deficiency as a clinically relevant biomarker of PARP1/2 inhibitor sensitivity. In models of high-grade serous ovarian cancer (HGS-OVCa), CDK12 attenuation was sufficient to confer sensitivity to PARP1/2 inhibition, suppression of DNA repair via homologous recombination, and reduced expression of BRCA1. As one of only nine genes known to be significantly mutated in HGS-OVCa, CDK12 has properties that should confirm interest in its use as a biomarker, particularly in ongoing clinical trials of PARP1/2 inhibitors and other agents that trigger replication fork arrest. Cancer Res; 74(1); 287–97. ©2013 AACR.
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- 2023
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12. Supplementary Table 3 from Genome-wide Profiling of Genetic Synthetic Lethality Identifies CDK12 as a Novel Determinant of PARP1/2 Inhibitor Sensitivity
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Alan Ashworth, Christopher J. Lord, Rachael Natrajan, Kerry Fenwick, Ioannis Assiotis, Iwanka Kozarewa, Lina Chen, Sean Hooper, Rumana Rafiq, David Sims, James Campbell, Rachel Brough, Farah L. Rehman, Rowan E. Miller, Asha Konde, Jessica R. Frankum, and Ilirjana Bajrami
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PDF file 470K, Supplementary Table S3 shRNA constructs with Olaparib Drug Effect Z scores >1.96
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- 2023
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13. Supplementary Figures from Genome-wide Profiling of Genetic Synthetic Lethality Identifies CDK12 as a Novel Determinant of PARP1/2 Inhibitor Sensitivity
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Alan Ashworth, Christopher J. Lord, Rachael Natrajan, Kerry Fenwick, Ioannis Assiotis, Iwanka Kozarewa, Lina Chen, Sean Hooper, Rumana Rafiq, David Sims, James Campbell, Rachel Brough, Farah L. Rehman, Rowan E. Miller, Asha Konde, Jessica R. Frankum, and Ilirjana Bajrami
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PDF file 3292K, Supplementary Figure S1. Genome wide shRNA screen information. Supplementary Figure S2. Validation of ATAD5 as a genetic determinant of olaparib response. Supplementary Figure S3. A working model of PARP1/2 inhibitor-induced DNA repair. Supplementary Figure S4. Inhibition of CDK12 sensitises serous ovarian cancer cells to olaparib and cisplatin. Supplementary Figure S5. CDK12 silencing and the impact on expression of DNA repair proteins. Supplementary Figure S6. Targeting of CCNK sensitises serous ovarian cancer cells to olaparib and cisplatin. Supplementary Figure S7. Animal body weights from in vivo study
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- 2023
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14. Supplementary Table 5 from Genome-wide Profiling of Genetic Synthetic Lethality Identifies CDK12 as a Novel Determinant of PARP1/2 Inhibitor Sensitivity
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Alan Ashworth, Christopher J. Lord, Rachael Natrajan, Kerry Fenwick, Ioannis Assiotis, Iwanka Kozarewa, Lina Chen, Sean Hooper, Rumana Rafiq, David Sims, James Campbell, Rachel Brough, Farah L. Rehman, Rowan E. Miller, Asha Konde, Jessica R. Frankum, and Ilirjana Bajrami
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PDF file 54K, Supplementary Table S5. Tumor-specific CDK12 mutations described in publically available sequencing data
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- 2023
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15. Supplementary Information from Genome-wide Profiling of Genetic Synthetic Lethality Identifies CDK12 as a Novel Determinant of PARP1/2 Inhibitor Sensitivity
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Alan Ashworth, Christopher J. Lord, Rachael Natrajan, Kerry Fenwick, Ioannis Assiotis, Iwanka Kozarewa, Lina Chen, Sean Hooper, Rumana Rafiq, David Sims, James Campbell, Rachel Brough, Farah L. Rehman, Rowan E. Miller, Asha Konde, Jessica R. Frankum, and Ilirjana Bajrami
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PDF file 120K, Supplementary figure legends and supplementary materials and methods
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- 2023
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16. Genetic and immune landscape evolution defines subtypes of MMR deficient colorectal cancer
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Benjamin R. Challoner, Andrew Woolston, David Lau, Marta Buzzetti, Caroline Fong, Louise J. Barber, Gayathri Anandappa, Richard Crux, Ioannis Assiotis, Kerry Fenwick, Ruwaida Begum, Dipa Begum, Tom Lund, Nanna Sivamanoharan, Harold B. Sansano, Melissa Domingo-Arada, Amina Tran, Bryony Eccles, Richard Ellis, Stephen Falk, Mark Hill, Daniel Krell, Nirupa Murugaesu, Luke Nolan, Vanessa Potter, Mark Saunders, Kai-Keen Shiu, Sebastian Guettler, James L. Alexander, Héctor Lázare-Iglesias, James Kinross, Jamie Murphy, Katharina von Loga, David Cunningham, Ian Chau, Naureen Starling, Juan Ruiz-Bañobre, Tony Dhillon, and Marco Gerlinger
- Abstract
Mismatch repair deficient colorectal cancers have high mutation loads and many respond to immune checkpoint-inhibitors. We investigated how genetic and immune landscapes co-evolve in these tumors. All cases had high truncal mutation loads. Driver aberrations showed a clear hierarchy despite pervasive intratumor heterogeneity: Those in WNT/βCatenin, mitogen-activated protein kinase and TGFβ receptor family genes were almost always truncal. Immune evasion drivers were predominantly subclonal and showed parallel evolution. Pan-tumor evolution, subclonal evolution, and evolutionary stasis of genetic immune evasion drivers defined three MMRd CRC subtypes with distinct T-cell infiltrates. These immune evasion drivers have been implicated in checkpoint-inhibitor resistance. Clonality and subtype assessments are hence critical for predictive immunotherapy biomarker development. Cancer cell PD-L1 expression was conditional on loss of the intestinal homeobox transcription factor CDX2. This explains infrequent PD-L1 expression by cancer cells and likely contributes to the high recurrence risk of MMRd CRCs with impaired CDX2 expression.
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- 2022
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17. Detecting and Tracking Circulating Tumour DNA Copy Number Profiles during First Line Chemotherapy in Oesophagogastric Adenocarcinoma
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Michael Davidson, Louise J. Barber, Andrew Woolston, Catherine Cafferkey, Sonia Mansukhani, Beatrice Griffiths, Sing-Yu Moorcraft, Isma Rana, Ruwaida Begum, Ioannis Assiotis, Nik Matthews, Sheela Rao, David Watkins, Ian Chau, David Cunningham, Naureen Starling, Marco Gerlinger
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- 2019
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18. The Mutational Concordance of Fixed Formalin Paraffin Embedded and Fresh Frozen Gastro-Oesophageal Tumours Using Whole Exome Sequencing
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Christopher J. Lord, Syed Haider, Ioannis Assiotis, Irene Chong, Ruwaida Begum, Naureen Starling, Nik Matthews, Asif Chaudry, Marta Llorca-Cardenosa, David Watkins, Monica Terlizzo, Andrew Wotherspoon, Ian Chau, Lauren I. Aronson, Alistair G. Rust, Ritika Chauhan, Sheela Rao, John Alexander, David Cunningham, Kerry Fenwick, and Sacheen Kumar
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Tumour heterogeneity ,Concordance ,lcsh:Medicine ,Context (language use) ,03 medical and health sciences ,0302 clinical medicine ,medicine ,mutational concordance ,formalin fixed paraffin embedded ,Gene ,Exome sequencing ,030304 developmental biology ,0303 health sciences ,Massive parallel sequencing ,business.industry ,Communication ,lcsh:R ,biomarkers ,Cancer ,General Medicine ,medicine.disease ,030220 oncology & carcinogenesis ,Cancer research ,Biomarker (medicine) ,business ,exome sequencing ,gastro-oesophageal cancer - Abstract
1. Background: The application of massively parallel sequencing has led to the identification of aberrant druggable pathways and somatic mutations within therapeutically relevant genes in gastro-oesophageal cancer. Given the widespread use of formalin-fixed paraffin-embedded (FFPE) samples in the study of this disease, it would be beneficial, especially for the purposes of biomarker evaluation, to assess the concordance between comprehensive exome-wide sequencing data from archival FFPE samples originating from a prospective clinical study and those derived from fresh-frozen material. 2. Methods: We analysed whole-exome sequencing data to define the mutational concordance of 16 matched fresh-frozen and FFPE gastro-oesophageal tumours (N = 32) from a prospective clinical study. We assessed DNA integrity prior to sequencing and then identified coding mutations in genes that have previously been implicated in other cancers. In addition, we calculated the mutant-allele heterogeneity (MATH) for these samples. 3. Results: Although there was increased degradation of DNA in FFPE samples compared with frozen samples, sequencing data from only two FFPE samples failed to reach an adequate mapping quality threshold. Using a filtering threshold of mutant read counts of at least ten and a minimum of 5% variant allele frequency (VAF) we found that there was a high median mutational concordance of 97% (range 80.1–98.68%) between fresh-frozen and FFPE gastro-oesophageal tumour-derived exomes. However, the majority of FFPE tumours had higher mutant-allele heterogeneity (MATH) scores when compared with corresponding frozen tumours (p < 0.001), suggesting that FFPE-based exome sequencing is likely to over-represent tumour heterogeneity in FFPE samples compared to fresh-frozen samples. Furthermore, we identified coding mutations in 120 cancer-related genes, including those associated with chromatin remodelling and Wnt/β-catenin and Receptor Tyrosine Kinase signalling. 4. Conclusions: These data suggest that comprehensive genomic data can be generated from exome sequencing of selected DNA samples extracted from archival FFPE gastro-oesophageal tumour tissues within the context of prospective clinical trials.
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- 2021
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19. Visualization of intra tumor heterogeneity by simultaneous analysis of tumor and liquid biopsy samples in stage M neuroblastomas
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Louise J. Barber, Ruth Ladenstein, Matthew N. Davies, Louis Chesler, I.M. Ambros, Marco Gerlinger, Reza Abbasi, Teresa Gerber, SC Huetter, Maria Berneder, Dominik Bogen, Ioannis Assiotis, and Peter F. Ambros
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Pathology ,medicine.medical_specialty ,business.industry ,Medicine ,Stage (cooking) ,Liquid biopsy ,business ,Tumor heterogeneity ,Visualization - Published
- 2017
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20. Identification of 19 new risk loci and potential regulatory mechanisms influencing susceptibility to testicular germ cell tumor
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Chey Loveday, Kerry Fenwick, Peter Broderick, Philip J. Law, Trine B. Haugen, Tom Grotmol, Giulia Orlando, Kevin Litchfield, D. Timothy Bishop, Zsofia Kote-Jarai, Gabriele Migliorini, Fredrik Wiklund, Amy Holroyd, Robert Huddart, Nora Pashayan, Wenche Kristiansen, Alison M. Dunning, Kenneth Muir, Robert Karlsson, Max Levy, Ioannis Assiotis, Jérémie Nsengimana, Nick Orr, Richard S. Houlston, Julian Peto, Clare Turnbull, Douglas F. Easton, Alison Reid, Rosalind A. Eeles, Darshna Dudakia, and Janet Shipley
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Adult ,Male ,Risk ,0301 basic medicine ,Genotype ,Urology ,MEDLINE ,Testicular Germ Cell Tumor ,Single-nucleotide polymorphism ,Genome-wide association study ,Biology ,Polymorphism, Single Nucleotide ,Genome-wide association studies ,Re identification ,Article ,Young Adult ,03 medical and health sciences ,Text mining ,0302 clinical medicine ,Testicular Neoplasms ,Testicular cancer ,Genetics ,medicine ,Journal Article ,Humans ,Genetic Predisposition to Disease ,Gene ,Genetic association ,business.industry ,Gene Expression Profiling ,Molecular Sequence Annotation ,Germ cell tumours ,Middle Aged ,Neoplasms, Germ Cell and Embryonal ,medicine.disease ,Chromatin ,Gene expression profiling ,030104 developmental biology ,030220 oncology & carcinogenesis ,Cancer research ,business ,Genome-Wide Association Study - Abstract
Genome-wide association studies (GWAS) have transformed understanding of susceptibility to testicular germ cell tumors (TGCTs), but much of the heritability remains unexplained. Here we report a new GWAS, a meta- A nalysis with previous GWAS and a replication series, totaling 7,319 TGCT cases and 23,082 controls. We identify 19 new TGCT risk loci, roughly doubling the number of known TGCT risk loci to 44. By performing in situ Hi-C in TGCT cells, we provide evidence for a network of physical interactions among all 44 TGCT risk SNPs and candidate causal genes. Our findings implicate widespread disruption of developmental transcriptional regulators as a basis of TGCT susceptibility, consistent with failed primordial germ cell differentiation as an initiating step in oncogenesis. Defective microtubule assembly and dysregulation of KIT-MAPK signaling also feature as recurrently disrupted pathways. Our findings support a polygenic model of risk and provide insight into the biological basis of TGCT.
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- 2017
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21. Genome-wide Profiling of Genetic Synthetic Lethality Identifies CDK12 as a Novel Determinant of PARP1/2 Inhibitor Sensitivity
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Kerry Fenwick, Iwanka Kozarewa, James Campbell, Alan Ashworth, I. Bajrami, Asha Konde, J. Frankum, Farah L. Rehman, David Sims, Rachel Brough, Christopher J. Lord, Rowan E. Miller, R. Rafiq, Rachael Natrajan, Sean D. Hooper, Lina Chen, and Ioannis Assiotis
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Cancer Research ,endocrine system diseases ,Nude ,Poly (ADP-Ribose) Polymerase-1 ,Synthetic lethality ,Piperazines ,chemistry.chemical_compound ,Mice ,Random Allocation ,0302 clinical medicine ,PARP1 ,RNA, Small Interfering ,Enzyme Inhibitors ,Cancer ,Genetics ,Ovarian Neoplasms ,0303 health sciences ,Genome ,Immunohistochemistry ,Cyclin-Dependent Kinases ,3. Good health ,Ovarian Cancer ,Replication fork arrest ,Oncology ,5.1 Pharmaceuticals ,030220 oncology & carcinogenesis ,Female ,Poly(ADP-ribose) Polymerases ,Development of treatments and therapeutic interventions ,Human ,DNA repair ,Oncology and Carcinogenesis ,Cystadenocarcinoma ,Mice, Nude ,Biology ,Poly(ADP-ribose) Polymerase Inhibitors ,Small Interfering ,Article ,Olaparib ,03 medical and health sciences ,Rare Diseases ,Breast Cancer ,Animals ,Humans ,Oncology & Carcinogenesis ,Gene ,Germ-Line Mutation ,030304 developmental biology ,Genome, Human ,Gene Expression Profiling ,Human Genome ,Serous ,Survival Analysis ,Xenograft Model Antitumor Assays ,Cystadenocarcinoma, Serous ,Gene expression profiling ,Orphan Drug ,Good Health and Well Being ,chemistry ,Phthalazines ,RNA ,Homologous recombination ,Genome-Wide Association Study - Abstract
Small-molecule inhibitors of PARP1/2, such as olaparib, have been proposed to serve as a synthetic lethal therapy for cancers that harbor BRCA1 or BRCA2 mutations. Indeed, in clinical trials, PARP1/2 inhibitors elicit sustained antitumor responses in patients with germline BRCA gene mutations. In hypothesizing that additional genetic determinants might direct use of these drugs, we conducted a genome-wide synthetic lethal screen for candidate olaparib sensitivity genes. In support of this hypothesis, the set of identified genes included known determinants of olaparib sensitivity, such as BRCA1, RAD51, and Fanconi's anemia susceptibility genes. In addition, the set included genes implicated in established networks of DNA repair, DNA cohesion, and chromatin remodeling, none of which were known previously to confer sensitivity to PARP1/2 inhibition. Notably, integration of the list of candidate sensitivity genes with data from tumor DNA sequencing studies identified CDK12 deficiency as a clinically relevant biomarker of PARP1/2 inhibitor sensitivity. In models of high-grade serous ovarian cancer (HGS-OVCa), CDK12 attenuation was sufficient to confer sensitivity to PARP1/2 inhibition, suppression of DNA repair via homologous recombination, and reduced expression of BRCA1. As one of only nine genes known to be significantly mutated in HGS-OVCa, CDK12 has properties that should confirm interest in its use as a biomarker, particularly in ongoing clinical trials of PARP1/2 inhibitors and other agents that trigger replication fork arrest. Cancer Res; 74(1); 287–97. ©2013 AACR.
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- 2014
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22. Correction: Suppression of interferon gene expression overcomes resistance to MEK inhibition in KRAS-mutant colorectal cancer
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Steve Wagner, Georgios Vlachogiannis, Alexis De Haven Brandon, Melanie Valenti, Gary Box, Liam Jenkins, Caterina Mancusi, Annette Self, Floriana Manodoro, Ioannis Assiotis, Penny Robinson, Ritika Chauhan, Alistair G. Rust, Nik Matthews, Kate Eason, Khurum Khan, Naureen Starling, David Cunningham, Anguraj Sadanandam, Clare M. Isacke, Vladimir Kirkin, Nicola Valeri, and Steven R. Whittaker
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Cancer Research ,Genetics ,Molecular Biology - Abstract
A correction to this paper has been published and can be accessed via a link at the top of the paper.
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- 2019
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23. The genomic landscape of oesophagogastric junctional adenocarcinoma
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Mahrokh Nohadani, Lina Chen, Ioannis Assiotis, Iwanka Kozarewa, Zakaria Eltahir, Alina Lemnrau, M. Benson, Louise J. Barber, Christopher J. Lord, Ian Chau, David Gonzalez-de-Castro, Naureen Starling, Irene Chong, David Cunningham, Gordon Stamp, Sebastian Guettler, Isaac Garcia-Murillas, Andrew Wotherspoon, James Campbell, Alan Ashworth, Kerry Fenwick, Nick Orr, Sheela Rao, Sanna Hulkki, Maryou B. Lambros, and Saima Awan
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Genetics ,Mutation ,Microsatellite instability ,Biology ,medicine.disease ,medicine.disease_cause ,Pathology and Forensic Medicine ,Loss of heterozygosity ,Oesophagogastric junctional adenocarcinoma ,DNA Mutational Analysis ,medicine ,Adenocarcinoma ,Exome ,Exome sequencing - Abstract
The incidence of oesophagogastric junctional (OGJ) adenocarcinoma is rising rapidly in western countries, in contrast to the declining frequency of distal gastric carcinoma. Treatment options for adenocarcinomas involving the oesophagogastric junction are limited and the overall prognosis is extremely poor. To determine the genomic landscape of OGJ adenocarcinoma, exomes of eight tumours and matched germline DNA were subjected to massively parallel DNA sequencing. Microsatellite instability was observed in three tumours which coincided with an elevated number of somatic mutations. In total, 117 genes were identified that had predicted coding alterations in more than one tumour. Potentially actionable coding mutations were identified in 67 of these genes, including those in CR2, HGF , FGFR4, and ESRRB. Twenty-nine genes harbouring somatic coding mutations and copy number changes in the MSS OGJ dataset are also known to be altered with similar predicted functional consequence in other tumour types. Compared with the published mutational profile of gastric cancers, 49% (57/117) of recurrently mutated genes were unique to OGJ tumours. TP53, SYNE1, and ARID1A were amongst the most frequently mutated genes in a larger OGJ cohort. Our study provides an insight into the mutational landscape of OGJ adenocarcinomas and confirms that this is a highly mutated and heterogeneous disease. Furthermore, we have uncovered somatic mutations in therapeutically relevant genes which may represent candidate drug targets.
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- 2013
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24. Efficacy of Chemotherapy in BRCA1/2 Mutation Carrier Ovarian Cancer in the Setting of PARP Inhibitor Resistance: A Multi-Institutional Study
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Shahneen Sandhu, Martin Gore, Christopher J. Lord, Jacques De Greve, Johann S. de Bono, Ursula A. Matulonis, Vincent Castonguay, C. Bethan Powell, T. Atkinson, Timothy A. Yap, Stan B. Kaye, Susana Banerjee, Joo Ern Ang, Michael Friedlander, Ronnie Shapira-Frommer, Kerry Fenwick, James Campbell, Alan Ashworth, Bella Kaufman, Hilda High, Lee-may Chen, Lina Chen, Ioannis Assiotis, Amit M. Oza, Charlie Gourley, Iwanka Kozarewa, Louise J. Barber, and Laboratory for Medical and Molecular Oncology
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Adult ,Oncology ,Heterozygote ,Cancer Research ,medicine.medical_specialty ,medicine.medical_treatment ,inhibitor resistance ,Poly(ADP-ribose) Polymerase Inhibitors ,Olaparib ,chemistry.chemical_compound ,Risk Factors ,Ovarian cancer ,Internal medicine ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Humans ,Enzyme Inhibitors ,Germ-Line Mutation ,Aged ,Neoplasm Staging ,Retrospective Studies ,BRCA2 Protein ,Ovarian Neoplasms ,Chemotherapy ,BRCA1 Protein ,business.industry ,BRCA mutation ,Cancer ,Middle Aged ,Prognosis ,medicine.disease ,Surgery ,Treatment Outcome ,chemistry ,Drug Resistance, Neoplasm ,Response Evaluation Criteria in Solid Tumors ,PARP inhibitor ,Female ,Cancer biomarkers ,Neoplasm Grading ,business - Abstract
Purpose: Preclinical data suggest that exposure to PARP inhibitors (PARPi) may compromise benefit to subsequent chemotherapy, particularly platinum-based regimens, in patients with BRCA1/2 mutation carrier ovarian cancer (PBMCOC), possibly through the acquisition of secondary BRCA1/2 mutations. The efficacy of chemotherapy in the PARPi-resistant setting was therefore investigated. Experimental Design: We conducted a retrospective review of PBMCOC who received chemotherapy following disease progression on olaparib, administered at ≥200 mg twice daily for one month or more. Tumor samples were obtained in the post-olaparib setting where feasible and analyzed by massively parallel sequencing. Results: Data were collected from 89 patients who received a median of 3 (range 1–11) lines of pre-olaparib chemotherapy. The overall objective response rate (ORR) to post-olaparib chemotherapy was 36% (24 of 67 patients) by Response Evaluation Criteria in Solid Tumors (RECIST) and 45% (35 of 78) by RECIST and/or Gynecologic Cancer InterGroup (GCIG) CA125 criteria with median progression-free survival (PFS) and overall survival (OS) of 17 weeks [95% confidence interval (CI), 13–21] and 34 weeks (95% CI, 26–42), respectively. For patients receiving platinum-based chemotherapy, ORRs were 40% (19 of 48) and 49% (26/53), respectively, with a median PFS of 22 weeks (95% CI, 15–29) and OS of 45 weeks (95% CI, 15–75). An increased platinum-to-platinum interval was associated with an increased OS and likelihood of response following post-olaparib platinum. No evidence of secondary BRCA1/2 mutation was detected in tumor samples of six PARPi-resistant patients [estimated frequency of such mutations adjusted for sample size: 0.125 (95%-CI: 0–0.375)]. Conclusions: Heavily pretreated PBMCOC who are PARPi-resistant retain the potential to respond to subsequent chemotherapy, including platinum-based agents. These data support the further development of PARPi in PBMCOC. Clin Cancer Res; 19(19); 5485–93. ©2013 AACR.
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- 2013
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25. Secondary mutations in BRCA2 associated with clinical resistance to a PARP inhibitor
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Stan B. Kaye, Victor Moreno, Jorge S. Reis-Filho, L Rhoda Molife, Kerry Fenwick, Johann S. de Bono, Daniel Nava Rodrigues, Iwanka Kozarewa, Louise J. Barber, James Campbell, Alan Ashworth, Shahneen Sandhu, Christopher J. Lord, Lina Chen, Ioannis Assiotis, and Joaquin Mateo
- Subjects
Mutation ,Massive parallel sequencing ,endocrine system diseases ,Synthetic lethality ,Drug resistance ,Biology ,Bioinformatics ,medicine.disease_cause ,Poly (ADP-Ribose) Polymerase Inhibitor ,Pathology and Forensic Medicine ,Olaparib ,chemistry.chemical_compound ,chemistry ,PARP inhibitor ,medicine ,Cancer research ,Cancer biomarkers ,skin and connective tissue diseases - Abstract
PARP inhibitors (PARPi) for the treatment of BRCA1 or BRCA2 deficient tumours are currently the focus of seminal clinical trials exploiting the concept of synthetic lethality. Although clinical resistance to PARPi has been described, the mechanism underlying this has not been elucidated. Here, we investigate tumour material from patients who had developed resistance to the PARPi olaparib, subsequent to showing an initial clinical response. Massively parallel DNA sequencing of treatment-naive and post-olaparib treatment biopsies identified tumour-specific BRCA2 secondary mutations in olaparib-resistant metastases. These secondary mutations restored full-length BRCA2 protein, and most likely cause olaparib resistance by re-establishing BRCA2 function in the tumour cells.
- Published
- 2013
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26. Genome-wide analysis of p63 binding sites identifies AP-2 factors as co-regulators of epidermal differentiation
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Nick Orr, Alan Ashworth, Marketa Zvelebil, Géraldine Pivato, Ioannis Assiotis, Alexandra E. Henry, Constantinos Mitsopoulos, Simon S. McDade, Iwanka Kozarewa, Dennis J. McCance, Christopher J. Lord, Daksha Patel, Jarle Hakas, and Kerry Fenwick
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Keratinocytes ,Cellular differentiation ,Biology ,Gene Regulation, Chromatin and Epigenetics ,TFAP2A ,03 medical and health sciences ,0302 clinical medicine ,Genetics ,Transcriptional regulation ,Humans ,Regulatory Elements, Transcriptional ,Gene ,Transcription factor ,Cells, Cultured ,030304 developmental biology ,Regulation of gene expression ,0303 health sciences ,Binding Sites ,Genome, Human ,Tumor Suppressor Proteins ,Cell Differentiation ,Molecular Sequence Annotation ,Phenotype ,Cleft Palate ,Epidermal Cells ,Gene Expression Regulation ,Transcription Factor AP-2 ,030220 oncology & carcinogenesis ,Tumor Suppressor Protein p53 ,Chromatin immunoprecipitation ,Transcription Factors - Abstract
The p63 transcription factor (TP63) is critical in development, growth and differentiation of stratifying epithelia. This is highlighted by the severity of congenital abnormalities caused by TP63 mutations in humans, the dramatic phenotypes in knockout mice and de-regulation of TP63 expression in neoplasia altering the tumour suppressive roles of the TP53 family. In order to define the normal role played by TP63 and provide the basis for better understanding how this network is perturbed in disease, we used chromatin immunoprecipitation combined with massively parallel sequencing (ChIP-seq) to identify >7500 high-confidence TP63-binding regions across the entire genome, in primary human neonatal foreskin keratinocytes (HFKs). Using integrative strategies, we demonstrate that only a subset of these sites are bound by TP53 in response to DNA damage. We identify a role for TP63 in transcriptional regulation of multiple genes genetically linked to cleft palate and identify AP-2alpha (TFAP2A) as a co-regulator of a subset of these genes. We further demonstrate that AP-2gamma (TFAP2C) can bind a subset of these regions and that acute depletion of either TFAP2A or TFAP2C alone is sufficient to reduce terminal differentiation of organotypic epidermal skin equivalents, indicating overlapping physiological functions with TP63.
- Published
- 2012
27. Whole exome DNA sequence analysis of Brca2 and Trp53 deficient mouse mammary gland tumours
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Lorenzo Melchor, Iwanka Kozarewa, Wenbin Wei, Kerry Fenwick, Javier Armisen-Garrido, Christopher J. Lord, Amanda Swain, Howard Kendrick, Lina Chen, Ioannis Assiotis, Jeffrey C. Francis, Matthew J. Smalley, James Campbell, and Alan Ashworth
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DNA Copy Number Variations ,Chromosomal Proteins, Non-Histone ,Genes, BRCA2 ,Mammary gland ,Mutation, Missense ,Breast Neoplasms ,Mice, Transgenic ,Protein Serine-Threonine Kinases ,Biology ,Genome ,DNA sequencing ,Pathology and Forensic Medicine ,RC0254 ,Gene Knockout Techniques ,Germline mutation ,Antigens, CD ,Signaling Lymphocytic Activation Molecule Family ,medicine ,Animals ,Humans ,Receptors, Immunologic ,skin and connective tissue diseases ,Exome ,Gene ,Germ-Line Mutation ,Exome sequencing ,Ovarian Neoplasms ,Genetics ,Mammary Neoplasms, Experimental ,Cancer ,DNA, Neoplasm ,Sequence Analysis, DNA ,medicine.disease ,Disease Models, Animal ,medicine.anatomical_structure ,Cancer research ,Female ,Tumor Suppressor Protein p53 - Abstract
Germline mutations in the tumour suppressor BRCA2 predispose to breast, ovarian and a number of other human cancers. Brca2-deficient mouse models are used for preclinical studies but the pattern of genomic alterations in these tumours has not yet been described in detail. We have performed whole-exome DNA sequencing analysis of mouse mammary tumours from Blg-Cre Brca2(f/f) Trp53(f/f) animals, a model of BRCA2-deficient human cancer. We also used the sequencing data to estimate DNA copy number alterations in these tumours and identified a recurrent copy number gain in Met, which has been found amplified in other mouse mammary cancer models. Through a comparative genomic analysis, we identified several mouse Blg-Cre Brca2(f/f) Trp53(f/f) mammary tumour somatic mutations in genes that are also mutated in human cancer, but few of these genes have been found frequently mutated in human breast cancer. A more detailed analysis of these somatic mutations revealed a set of genes that are mutated in human BRCA2 mutant breast and ovarian tumours and that are also mutated in mouse Brca2-null, Trp53-null mammary tumours. Finally, a DNA deletion surrounded by microhomology signature found in human BRCA1/2-deficient cancers was not common in the genome of these mouse tumours. Although a useful model, there are some differences in the genomic landscape of tumours arising in Blg-Cre Brca2(f/f) Trp53(f/f) mice compared to human BRCA-mutated breast cancers. Therefore, this needs to be taken into account in the use of this model.
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- 2015
28. Poly (ADP-ribose) polymerase (PARP) inhibitors for the treatment of advanced germline BRCA2 mutant prostate cancer
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Ruth Riisnaes, Peter C.C. Fong, Christopher J. Lord, Stan B. Kaye, Nina Tunariu, Kerry Fenwick, David Olmos, Susana Miranda, J.S. de Bono, Heidrun Gevensleben, L. R. Molife, Dow-Mu Koh, Lucy Hylands, James Campbell, Alan Ashworth, Lina Chen, Ioannis Assiotis, Iwanka Kozarewa, Gerhardt Attard, Shahneen Sandhu, Aurelius Omlin, Alison Reid, T. A. Yap, and Louise J. Barber
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Mutation ,business.industry ,Poly ADP ribose polymerase ,Mutant ,Hematology ,medicine.disease_cause ,medicine.disease ,Molecular biology ,Poly (ADP-Ribose) Polymerase Inhibitor ,Germline ,Prostate cancer ,Oncology ,Medicine ,Cancer biomarkers ,business - Published
- 2013
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29. Unbiased analysis of potential targets of breast cancer susceptibility loci by Capture Hi-C
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Steven W. Wingett, Nicola H. Dryden, Takashi Nagano, Stefan Schoenfelder, Nichola Johnson, Maryou B K Lambros, Peter Fraser, Nick Orr, Eleni Perrakis, Frank Dudbridge, Rachael Natrajan, Ioannis Assiotis, Simon Andrews, Sarah Maguire, Kerry Fenwick, Iwanka Kozarewa, Laura Broome, James Campbell, Alan Ashworth, and Olivia Fletcher
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Method ,Genome-wide association study ,Regulatory Sequences, Nucleic Acid ,Genome ,Medical and Health Sciences ,Protein Interaction Mapping ,2.1 Biological and endogenous factors ,Aetiology ,Genetics (clinical) ,Oligonucleotide Array Sequence Analysis ,Cancer ,Genetics ,Tumor ,Research Support, Non-U.S. Gov't ,Chromosome Mapping ,Single Nucleotide ,Biological Sciences ,PVT1 ,Regulatory sequence ,Chromosomes, Human, Pair 2 ,Pair 2 ,MCF-7 Cells ,Pair 8 ,RNA, Long Noncoding ,Long Noncoding ,Chromosomes, Human, Pair 9 ,Sequence Analysis ,Chromosomes, Human, Pair 8 ,Human ,Pair 9 ,Protein Binding ,Biotechnology ,Hepatocyte Nuclear Factor 3-alpha ,Chromatin Immunoprecipitation ,Sequence analysis ,Bioinformatics ,Single-nucleotide polymorphism ,Breast Neoplasms ,Biology ,Real-Time Polymerase Chain Reaction ,Polymorphism, Single Nucleotide ,Chromosomes ,Cell Line ,Kruppel-Like Factor 4 ,Cell Line, Tumor ,Breast Cancer ,Journal Article ,Humans ,Genetic Predisposition to Disease ,Polymorphism ,Gene ,Homeodomain Proteins ,Nucleic Acid ,Genome, Human ,Human Genome ,Reproducibility of Results ,Sequence Analysis, DNA ,DNA ,RNA ,Human genome ,Regulatory Sequences ,Genome-Wide Association Study - Abstract
Genome-wide association studies have identified more than 70 common variants that are associated with breast cancer risk. Most of these variants map to non-protein-coding regions and several map to gene deserts, regions of several hundred kilobases lacking protein-coding genes. We hypothesized that gene deserts harbor long-range regulatory elements that can physically interact with target genes to influence their expression. To test this, we developed Capture Hi-C (CHi-C), which, by incorporating a sequence capture step into a Hi-C protocol, allows high-resolution analysis of targeted regions of the genome. We used CHi-C to investigate long-range interactions at three breast cancer gene deserts mapping to 2q35, 8q24.21, and 9q31.2. We identified interaction peaks between putative regulatory elements (“bait fragments”) within the captured regions and “targets” that included both protein-coding genes and long noncoding (lnc) RNAs over distances of 6.6 kb to 2.6 Mb. Target protein-coding genes were IGFBP5, KLF4, NSMCE2, and MYC; and target lncRNAs included DIRC3, PVT1, and CCDC26. For one gene desert, we were able to define two SNPs (rs12613955 and rs4442975) that were highly correlated with the published risk variant and that mapped within the bait end of an interaction peak. In vivo ChIP-qPCR data show that one of these, rs4442975, affects the binding of FOXA1 and implicate this SNP as a putative functional variant.
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- 2014
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30. The genomic landscape of oesophagogastric junctional adenocarcinoma
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Irene Y, Chong, David, Cunningham, Louise J, Barber, James, Campbell, Lina, Chen, Iwanka, Kozarewa, Kerry, Fenwick, Ioannis, Assiotis, Sebastian, Guettler, Isaac, Garcia-Murillas, Saima, Awan, Maryou, Lambros, Naureen, Starling, Andrew, Wotherspoon, Gordon, Stamp, David, Gonzalez-de-Castro, Martin, Benson, Ian, Chau, Sanna, Hulkki, Mahrokh, Nohadani, Zakaria, Eltahir, Alina, Lemnrau, Nicholas, Orr, Sheela, Rao, Christopher J, Lord, and Alan, Ashworth
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Adult ,Male ,DNA Copy Number Variations ,Esophageal Neoplasms ,DNA Mutational Analysis ,Loss of Heterozygosity ,Adenocarcinoma ,Polymerase Chain Reaction ,Stomach Neoplasms ,Humans ,Exome ,Prospective Studies ,Adaptor Proteins, Signal Transducing ,Aged ,Mismatch Repair Endonuclease PMS2 ,Neoplasm Staging ,Adenosine Triphosphatases ,Genome, Human ,Nuclear Proteins ,DNA, Neoplasm ,Middle Aged ,Immunohistochemistry ,Neoplasm Proteins ,DNA-Binding Proteins ,DNA Repair Enzymes ,MutL Proteins ,Mutation ,Female ,Microsatellite Instability ,Esophagogastric Junction ,MutL Protein Homolog 1 - Abstract
The incidence of oesophagogastric junctional (OGJ) adenocarcinoma is rising rapidly in western countries, in contrast to the declining frequency of distal gastric carcinoma. Treatment options for adenocarcinomas involving the oesophagogastric junction are limited and the overall prognosis is extremely poor. To determine the genomic landscape of OGJ adenocarcinoma, exomes of eight tumours and matched germline DNA were subjected to massively parallel DNA sequencing. Microsatellite instability was observed in three tumours which coincided with an elevated number of somatic mutations. In total, 117 genes were identified that had predicted coding alterations in more than one tumour. Potentially actionable coding mutations were identified in 67 of these genes, including those in CR2, HGF , FGFR4, and ESRRB. Twenty-nine genes harbouring somatic coding mutations and copy number changes in the MSS OGJ dataset are also known to be altered with similar predicted functional consequence in other tumour types. Compared with the published mutational profile of gastric cancers, 49% (57/117) of recurrently mutated genes were unique to OGJ tumours. TP53, SYNE1, and ARID1A were amongst the most frequently mutated genes in a larger OGJ cohort. Our study provides an insight into the mutational landscape of OGJ adenocarcinomas and confirms that this is a highly mutated and heterogeneous disease. Furthermore, we have uncovered somatic mutations in therapeutically relevant genes which may represent candidate drug targets.
- Published
- 2013
31. Frequent germline deleterious mutations in DNA repair genes in familial prostate cancer cases are associated with advanced disease
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Antonis C. Antoniou, S Jugurnauth-Little, Ed Saunders, Zsofia Kote-Jarai, Malgorzata Tymrakiewicz, Iwanka Kozarewa, Rosemary A. Wilkinson, Michelle Guy, Tokhir Dadaev, Chee L. Goh, Koveela Govindasami, Kerry Fenwick, Daniel Leongamornlert, Daniel Barrowdale, Rosalind A. Eeles, Emma J. Sawyer, and Ioannis Assiotis
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Proband ,Adult ,Male ,Risk ,Cancer Research ,DNA Repair ,DNA repair ,Biology ,medicine.disease_cause ,urologic and male genital diseases ,Germline ,Familial prostate cancer ,Germline mutation ,Genetic variation ,medicine ,Humans ,Genetic Predisposition to Disease ,familial prostate cancer ,DNA repair gene mutations ,Gene ,Germ-Line Mutation ,Aged ,Genetics ,Aged, 80 and over ,Mutation ,Prostatic Neoplasms ,Genetics and Genomics ,Middle Aged ,relative risk ,Oncology ,next-generation sequencing - Abstract
Background: Prostate cancer (PrCa) is one of the most common diseases to affect men worldwide and among the leading causes of cancer-related death. The purpose of this study was to use second-generation sequencing technology to assess the frequency of deleterious mutations in 22 tumour suppressor genes in familial PrCa and estimate the relative risk of PrCa if these genes are mutated. Methods: Germline DNA samples from 191 men with 3 or more cases of PrCa in their family were sequenced for 22 tumour suppressor genes using Agilent target enrichment and Illumina technology. Analysis for genetic variation was carried out by using a pipeline consisting of BWA, Genome Analysis Toolkit (GATK) and ANNOVAR. Clinical features were correlated with mutation status using standard statistical tests. Modified segregation analysis was used to determine the relative risk of PrCa conferred by the putative loss-of-function (LoF) mutations identified. Results: We discovered 14 putative LoF mutations in 191 samples (7.3%) and these mutations were more frequently associated with nodal involvement, metastasis or T4 tumour stage (P=0.00164). Segregation analysis of probands with European ancestry estimated that LoF mutations in any of the studied genes confer a relative risk of PrCa of 1.94 (95% CI: 1.56–2.42). Conclusions: These findings show that LoF mutations in DNA repair pathway genes predispose to familial PrCa and advanced disease and therefore warrants further investigation. The clinical utility of these findings will become increasingly important as targeted screening and therapies become more widespread.
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- 2013
32. A genetic screen using the PiggyBac transposon in haploid cells identifies Parp1 as a mediator of olaparib toxicity
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Iwanka Kozarewa, Rachel Brough, Kerry Fenwick, Farah L. Rehman, Fredrik Wallberg, Christopher J. Lord, Lina Chen, Ioannis Assiotis, Ilirjana Bajrami, Stephen J. Pettitt, James Campbell, and Alan Ashworth
- Subjects
Genetic Screens ,Mutant ,Poly (ADP-Ribose) Polymerase-1 ,Haploidy ,Biochemistry ,Poly (ADP-Ribose) Polymerase Inhibitor ,Piperazines ,Mice ,DNA transposons ,chemistry.chemical_compound ,Molecular cell biology ,0302 clinical medicine ,PARP1 ,RNA interference ,Drug Discovery ,Drug Interactions ,Genetics ,0303 health sciences ,Multidisciplinary ,3. Good health ,Nucleic acids ,030220 oncology & carcinogenesis ,Medicine ,Poly(ADP-ribose) Polymerases ,Transposons ,Research Article ,Transposable element ,Drugs and Devices ,Drug Research and Development ,Science ,DNA repair ,Poly(ADP-ribose) Polymerase Inhibitors ,Biology ,Olaparib ,03 medical and health sciences ,Genetic Mutation ,Animals ,Humans ,Genetic Testing ,Embryonic Stem Cells ,030304 developmental biology ,fungi ,DNA ,chemistry ,Mutagenesis ,Pharmacogenetics ,Mutation ,DNA Transposable Elements ,Phthalazines ,Transposon mutagenesis ,Gene Function ,Genetic screen - Abstract
Genetic perturbation screens have the potential to dissect a wide range of cellular phenotypes. Such screens have historically been difficult in diploid mammalian cells. The recent derivation of haploid embryonic stem cells provides an opportunity to cause loss of function mutants with a random mutagen in a mammalian cell with a normal genetic background. We describe an approach to genetic screens that exploits the highly active piggyBac transposon in haploid mammalian cells. As an example of haploid transposon (HTP) screening, we apply this approach to identifying determinants of cancer drug toxicity and resistance. In a screen for 6-thioguanine resistance we recovered components of the DNA mismatch repair pathway, a known requirement for toxicity. In a further screen for resistance to the clinical poly(ADP-ribose) polymerase (PARP) inhibitor olaparib we recovered multiple Parp1 mutants. Our results show that olaparib toxicity to normal cells is mediated predominantly via Parp1, and suggest that the clinical side effects of olaparib may be on target. The transposon mutant libraries are stable and can be readily reused to screen other drugs. The screening protocol described has several advantages over other methods such as RNA interference: it is rapid and low cost, and mutations can be easily reverted to establish causality.
- Published
- 2013
33. Secondary mutations in BRCA2 associated with clinical resistance to a PARP inhibitor
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Louise J, Barber, Shahneen, Sandhu, Lina, Chen, James, Campbell, Iwanka, Kozarewa, Kerry, Fenwick, Ioannis, Assiotis, Daniel Nava, Rodrigues, Jorge S, Reis Filho, Victor, Moreno, Joaquin, Mateo, L Rhoda, Molife, Johann, De Bono, Stan, Kaye, Christopher J, Lord, and Alan, Ashworth
- Subjects
BRCA2 Protein ,Male ,Ovarian Neoplasms ,DNA Mutational Analysis ,Antineoplastic Agents ,Sequence Analysis, DNA ,Adenocarcinoma ,Middle Aged ,Poly(ADP-ribose) Polymerase Inhibitors ,Combined Modality Therapy ,Piperazines ,Breast Neoplasms, Male ,Gene Expression Regulation, Neoplastic ,Drug Resistance, Neoplasm ,Mutation ,Humans ,Phthalazines ,Female - Abstract
PARP inhibitors (PARPi) for the treatment of BRCA1 or BRCA2 deficient tumours are currently the focus of seminal clinical trials exploiting the concept of synthetic lethality. Although clinical resistance to PARPi has been described, the mechanism underlying this has not been elucidated. Here, we investigate tumour material from patients who had developed resistance to the PARPi olaparib, subsequent to showing an initial clinical response. Massively parallel DNA sequencing of treatment-naive and post-olaparib treatment biopsies identified tumour-specific BRCA2 secondary mutations in olaparib-resistant metastases. These secondary mutations restored full-length BRCA2 protein, and most likely cause olaparib resistance by re-establishing BRCA2 function in the tumour cells.
- Published
- 2012
34. Genome-wide functional screen identifies a compendium of genes affecting sensitivity to tamoxifen
- Author
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Ioannis Assiotis, Tim Dexter, Costas Mitsopoulos, Marketa Zvelebil, Ana M. Mendes-Pereira, Alan Ashworth, Christopher J. Lord, Kerry Fenwick, Iwanka Kozarewa, Jarle Hakas, and David Sims
- Subjects
Breast Neoplasms ,Biology ,Genome ,Small hairpin RNA ,RNA interference ,Cell Line, Tumor ,medicine ,Gene silencing ,Humans ,Genetic Testing ,Breast Cancer Special Feature ,BAP1 ,Multidisciplinary ,Massive parallel sequencing ,Genome, Human ,Reproducibility of Results ,Human genetics ,Tamoxifen ,Drug Resistance, Neoplasm ,Cancer research ,Female ,RNA Interference ,Drug Screening Assays, Antitumor ,medicine.drug ,Genes, Neoplasm ,Signal Transduction - Abstract
Therapies that target estrogen signaling have made a very considerable contribution to reducing mortality from breast cancer. However, resistance to tamoxifen remains a major clinical problem. Here we have used a genome-wide functional profiling approach to identify multiple genes that confer resistance or sensitivity to tamoxifen. Combining whole-genome shRNA screening with massively parallel sequencing, we have profiled the impact of more than 56,670 RNA interference reagents targeting 16,487 genes on the cellular response to tamoxifen. This screen, along with subsequent validation experiments, identifies a compendium of genes whose silencing causes tamoxifen resistance (including BAP1 , CLPP , GPRC5D , NAE1 , NF1 , NIPBL , NSD1 , RAD21 , RARG , SMC3 , and UBA3 ) and also a set of genes whose silencing causes sensitivity to this endocrine agent ( C10orf72 , C15orf55/NUT , EDF1 , ING5 , KRAS , NOC3L , PPP1R15B , RRAS2 , TMPRSS2 , and TPM4 ). Multiple individual genes, including NF1 , a regulator of RAS signaling, also correlate with clinical outcome after tamoxifen treatment.
- Published
- 2011
35. Comprehensive Genomic Analysis of a BRCA2 Deficient Human Pancreatic Cancer
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Christopher J. Lord, Juan M. Rosa Rosa, Costas Mitsopoulos, Jarle Hakas, Alan Ashworth, David Sims, Marketa Zvelebil, Louise J. Barber, Ioannis Assiotis, Kerry Fenwick, and Iwanka Kozarewa
- Subjects
endocrine system diseases ,Science ,Genomics ,Adenocarcinoma ,Biology ,Genome ,Metastasis ,Pancreatic Cancer ,Cell Line, Tumor ,Molecular Cell Biology ,Basic Cancer Research ,Gastrointestinal Tumors ,Genetics ,Humans ,Genomic library ,Genome Sequencing ,International HapMap Project ,Exome ,BRCA2 Protein ,Comparative Genomic Hybridization ,Multidisciplinary ,Genome, Human ,Chromosome Mapping ,Computational Biology ,Cancers and Neoplasms ,Sequence Analysis, DNA ,Human genetics ,Pancreatic Neoplasms ,Somatic Cells ,Oncology ,Medicine ,Human genome ,Cellular Types ,Research Article ,Comparative genomic hybridization - Abstract
Capan-1 is a well-characterised BRCA2-deficient human cell line isolated from a liver metastasis of a pancreatic adenocarcinoma. Here we report a genome-wide assessment of structural variations and high-depth exome characterization of single nucleotide variants and small insertion/deletions in Capan-1. To identify potential somatic and tumour-associated variations in the absence of a matched-normal cell line, we devised a novel method based on the analysis of HapMap samples. We demonstrate that Capan-1 has one of the most rearranged genomes sequenced to date. Furthermore, small insertions and deletions are detected more frequently in the context of short sequence repeats than in other genomes. We also identify a number of novel mutations that may represent genetic changes that have contributed to tumour progression. These data provide insight into the genomic effects of loss of BRCA2 function.
- Published
- 2011
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36. High-throughput RNA interference screening using pooled shRNA libraries and next generation sequencing
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Iwanka Kozarewa, Ana M. Mendes-Pereira, Cristina Lombardelli, Costas Mitsopoulos, Kerry Fenwick, Marketa Zvelebil, Nirupa Murugaesu, Clare M. Isacke, Ioannis Assiotis, Jessica Frankum, Christopher J. Lord, Maria Antonietta Cerone, Alan Ashworth, David Sims, Darren J. Burgess, and Jarle Hakas
- Subjects
Pipeline (computing) ,Genetic Vectors ,Method ,Computational biology ,Biology ,Transfection ,Sensitivity and Specificity ,DNA sequencing ,Small hairpin RNA ,User-Computer Interface ,RNA interference ,Humans ,Genomic library ,RNA, Small Interfering ,Throughput (business) ,Gene Library ,Genetics ,Base Sequence ,Sequence Analysis, RNA ,Lentivirus ,RNA ,Computational Biology ,Reproducibility of Results ,HEK293 Cells ,Scalability ,RNA Interference ,Sequence Alignment ,Algorithms ,Plasmids - Abstract
RNA interference (RNAi) screening is a state-of-the-art technology that enables the dissection of biological processes and disease-related phenotypes. The commercial availability of genome-wide, short hairpin RNA (shRNA) libraries has fueled interest in this area but the generation and analysis of these complex data remain a challenge. Here, we describe complete experimental protocols and novel open source computational methodologies, shALIGN and shRNAseq, that allow RNAi screens to be rapidly deconvoluted using next generation sequencing. Our computational pipeline offers efficient screen analysis and the flexibility and scalability to quickly incorporate future developments in shRNA library technology.
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