174 results on '"Chung YM"'
Search Results
2. Synthesis of γ-benzopyranones using sonogashira coupling and 18-crown-6 ether mediated cyclization
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Chuang, DW, primary, El-Shazly, M, additional, Barve Balaji, D, additional, Chung, YM, additional, Chang, FR, additional, and Wu, YC, additional
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- 2012
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3. A corpus-based approach to comparative evaluation of statistical term association measures.
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Chung YM and Lee JY
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- 2001
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4. A genetic study of Behçet's disease in Taiwan Chinese
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Liu Jh, Fang Liao, Tsai St, and Chung Ym
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Male ,medicine.medical_specialty ,Eye disease ,Immunology ,Taiwan ,Immunogenetics ,Behcet's disease ,Disease ,Biochemistry ,Gastroenterology ,Antigen ,Gene Frequency ,HLA Antigens ,Internal medicine ,Immunopathology ,HLA-DQ Antigens ,Genetics ,medicine ,Immunology and Allergy ,Humans ,HLA-D Antigens ,business.industry ,Incidence (epidemiology) ,Behcet Syndrome ,Significant difference ,General Medicine ,HLA-DR Antigens ,medicine.disease ,stomatognathic diseases ,Female ,Disease Susceptibility ,business - Abstract
The frequency of HLA-A, B and C antigen in 53 patients and HLA-DR, DQ and Dn antigen in 31 patients of Behcet's disease was studied. All patients were Chinese, and diagnosis was made according to the Japanese Research Committee on Behcet's disease. A significantly increased incidence of HLA-B51 (P less than 0.001) and a significantly decreased incidence of HLA-B16 (P less than 0.01) was found. No significant difference was found in HLA-DR, DQ and DN antigens.
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- 1987
5. Morphological multiparameter filtration and persistent homology in mitochondrial image analysis.
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Chung YM, Hu CS, Sun E, and Tseng HC
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- Humans, Cell Cycle Proteins genetics, Cell Cycle Proteins metabolism, Transcription Factor TFIIIA genetics, Transcription Factor TFIIIA metabolism, Mutation, Software, Mitochondria metabolism, Mitochondria genetics, Membrane Transport Proteins genetics, Membrane Transport Proteins metabolism, Image Processing, Computer-Assisted methods
- Abstract
The complexity of branching and curvilinear morphology of a complete mitochondrial network within each cell is challenging to analyze and quantify. To address this challenge, we developed an image analysis technique using persistent homology with a multiparameter filtration framework, combining image processing techniques in mathematical morphology. We show that such filtrations contain both topological and geometric information about complex cellular organelle structures, which allows a software program to extract meaningful features. Using this information, we also develop a connectivity index that describes the morphology of the branching patterns. As proof of concept, we utilize this approach to study how mitochondrial networks are altered by genetic changes in the Optineurin gene. Mutations in the autophagy gene Optineurin (OPTN) are associated with primary open-angle glaucoma (POAG), amyotrophic lateral sclerosis (ALS), and Paget's disease of the bone, but the pathophysiological mechanism is unclear. We utilized the proposed mathematical morphology-based multiparameter filtration and persistent homology approach to analyze and quantitatively compare how changes in the OPTN gene alter mitochondrial structures from their normal interconnected, tubular morphology into scattered, fragmented pieces., Competing Interests: NO authors have competing interests., (Copyright: © 2024 Chung et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2024
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6. Nutritional Intensive Support in a Pediatric Patient With Severe Traumatic Brain Injury: A Case Report.
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Lee IS, Kang K, Chung YM, and Lee J
- Abstract
Estimating the nutritional requirements for pediatric patients requires a comprehensive approach with various factors including age, gender, body mass index, and physical activity level, due to the significant growth and developmental changes observed in this population. This complexity renders the use of a simplistic generalization or a standard formula impractical. A number of methodologies have been established to calculate nutritional needs for the pediatric population. However, the application of these methodologies is challenging due to the variability in the aforementioned factors. Determining nutritional requirements for pediatric patients with underlying medical conditions is complicate, influenced by variables such as the nature of the illness, treatment modalities, and the patient's overall condition. Nutritional support in severely traumatically brain-injured pediatric patients is directly correlated with prognosis and growth outcomes. Therefore, this case study aims to validate existing methodologies for estimating nutritional requirements in pediatric patients with severe traumatic brain injury and to provide primary data for the development of effective nutritional support strategies. A case of a 5-year-old male patient admitted to the intensive care unit due to severe traumatic brain injury is examined. Future case studies and ongoing research are imperative to ensure the safe and effective nutritional support of pediatric patients with severe traumatic brain injury., Competing Interests: Conflict of Interest: The authors declare that they have no competing interests., (Copyright © 2024. The Korean Society of Clinical Nutrition.)
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- 2024
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7. Androgen loss weakens anti-tumor immunity and accelerates brain tumor growth.
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Lee J, Chung YM, Curtin L, Silver DJ, Hao Y, Li C, Volovetz J, Hong ES, Jarmula J, Wang SZ, Kay KE, Berens M, Nicosia M, Swanson KR, Sharifi N, and Lathia JD
- Abstract
Many cancers, including glioblastoma (GBM), have a male-biased sex difference in incidence and outcome. The underlying reasons for this sex bias are unclear but likely involve differences in tumor cell state and immune response. This effect is further amplified by sex hormones, including androgens, which have been shown to inhibit anti-tumor T cell immunity. Here, we show that androgens drive anti-tumor immunity in brain tumors, in contrast to its effect in other tumor types. Upon castration, tumor growth was accelerated with attenuated T cell function in GBM and brain tumor models, but the opposite was observed when tumors were located outside the brain. Activity of the hypothalamus-pituitary-adrenal gland (HPA) axis was increased in castrated mice, particularly in those with brain tumors. Blockade of glucocorticoid receptors reversed the accelerated tumor growth in castrated mice, indicating that the effect of castration was mediated by elevated glucocorticoid signaling. Furthermore, this mechanism was not GBM specific, but brain specific, as hyperactivation of the HPA axis was observed with intracranial implantation of non-GBM tumors in the brain. Together, our findings establish that brain tumors drive distinct endocrine-mediated mechanisms in the androgen-deprived setting and highlight the importance of organ-specific effects on anti-tumor immunity., Competing Interests: Competing interests N.S. is a co-inventor on a Cleveland Clinic patent on HSD3B1. The other authors declare no competing interest.
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- 2024
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8. Chronic hypoxia stabilizes 3βHSD1 via autophagy suppression.
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Qin L, Berk M, Chung YM, Cui D, Zhu Z, Chakraborty AA, and Sharifi N
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- Male, Humans, Androgens metabolism, Androgen Antagonists therapeutic use, Receptors, Androgen metabolism, Cell Line, Tumor, Prostatic Neoplasms pathology, Prostatic Neoplasms, Castration-Resistant genetics
- Abstract
Progression of prostate cancer depends on androgen receptor, which is usually activated by androgens. Therefore, a mainstay treatment is androgen deprivation therapy. Unfortunately, despite initial treatment response, resistance nearly always develops, and disease progresses to castration-resistant prostate cancer (CRPC), which remains driven by non-gonadal androgens synthesized in prostate cancer tissues. 3β-Hydroxysteroid dehydrogenase/Δ
5 -->4 isomerase 1 (3βHSD1) catalyzes the rate-limiting step in androgen synthesis. However, how 3βHSD1, especially the "adrenal-permissive" 3βHSD1(367T) that permits tumor synthesis of androgen from dehydroepiandrosterone (DHEA), is regulated at the protein level is not well understood. Here, we investigate how hypoxia regulates 3βHSD1(367T) protein levels. Our results show that, in vitro, hypoxia stabilizes 3βHSD1 protein by suppressing autophagy. Autophagy inhibition promotes 3βHSD1-dependent tumor progression. Hypoxia represses transcription of autophagy-related (ATG) genes by decreasing histone acetylation. Inhibiting deacetylase (HDAC) restores ATG gene transcription under hypoxia. Therefore, HDAC inhibition may be a therapeutic target for hypoxic tumor cells., Competing Interests: Declaration of interests N.S. reports grants from BMS and grants from Astellas outside the submitted work; in addition, N.S. has a patent for HSD3B1 in prostate cancer issued., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)- Published
- 2024
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9. Cr-catalysed ethylene dimerization in an ionic liquid-organic solvent biphasic system with perfect 1-butene selectivity.
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Thi Kim Chau N, Kim S, Lee HJ, Lee M, and Chung YM
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Cr-catalyzed ionic liquid-organic biphasic ethylene dimerization was realized with 100% 1-butene selectivity. The perfect α-olefin selectivity can be rationalized in terms of the poor solubility of the oligomerized long-chain olefins in ionic liquids, and enables the establishment of a dimerization process without any complicated and energy-intensive catalyst and byproduct separation processes.
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- 2023
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10. 3βHSD activity saturates at physiological substrate concentrations in intact cells.
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McManus JM, Chung YM, and Sharifi N
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- Humans, Male, Androstenediols, Androstenedione metabolism, Cell Line, Tumor, Dehydroepiandrosterone metabolism, Androgens, Prostatic Neoplasms pathology
- Abstract
Background: Conversion of adrenally produced dehydroepiandrosterone (DHEA) to the potent androgen dihydrotestosterone (DHT) is an important mechanism by which prostate cancer reaches castration resistance. At the start of this pathway is a branch point at which DHEA can be converted to Δ
4 -androstenedione by the enzyme 3β-hydroxysteroid dehydrogenase (3βHSD) or to Δ5 -androstenediol by 17βHSD. To better understand this process, we studied the kinetics of these reactions in cells., Methods: Prostate cancer cells (LNCaP cell line) were incubated with steroids (DHEA and Δ5 -androstenediol) over a range of concentrations and the steroid metabolism reaction products were measured by mass spectrometry or by high-performance liquid chromatography to determine reaction kinetics. To confirm the generalizability of results, experiments were also performed in JEG-3 placental choriocarcinoma cells., Results: The two reactions displayed very different saturation profiles, with only the 3βHSD-catalyzed reaction beginning to saturate within a physiological substrate concentration range. Strikingly, incubating LNCaP cells with low (in the ~10 nM range) concentrations of DHEA resulted in a large majority of the DHEA undergoing 3βHSD-catalyzed conversion to Δ4 -androstenedione, whereas high concentrations of DHEA (in the 100s of nM range) resulted in most of the DHEA undergoing 17βHSD-catalyzed conversion to Δ5 -androstenediol., Conclusion: Contrary to expectations from previous studies that used purified enzyme, cellular metabolism of DHEA by 3βHSD begins to saturate in the physiological concentration range, suggesting that fluctuations in DHEA concentrations could be buffered at the downstream active androgen level., (© 2023 The Authors. The Prostate published by Wiley Periodicals LLC.)- Published
- 2023
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11. Assessing nocturnal scratch with actigraphy in atopic dermatitis patients.
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Ji J, Venderley J, Zhang H, Lei M, Ruan G, Patel N, Chung YM, Giesting R, and Miller L
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Nocturnal scratch is one major factor leading to impaired quality of life in atopic dermatitis (AD) patients. Therefore, objectively quantifying nocturnal scratch events aids in assessing the disease state, treatment effect, and AD patients' quality of life. In this paper, we describe the use of actigraphy, highly predictive topological features, and a model-ensembling approach to develop an assessment of nocturnal scratch events by measuring scratch duration and intensity. Our assessment is tested in a clinical setting against the ground truth obtained from video recordings. The new approach addresses unmet challenges in existing studies, such as the lack of generalizability to real-world applications, the failure to capture finger scratches, and the limitations in the evaluation due to imbalanced data in the current literature. Furthermore, the performance evaluation shows agreement between derived digital endpoints and the video annotation ground truth, as well as patient-reported outcomes, which demonstrated the validity of the new assessment of nocturnal scratch., (© 2023. The Author(s).)
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- 2023
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12. Cancer-associated fibroblast-secreted glucosamine alters the androgen biosynthesis program in prostate cancer via HSD3B1 upregulation.
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Cui D, Li J, Zhu Z, Berk M, Hardaway A, McManus J, Chung YM, Alyamani M, Valle S, Tiwari R, Han B, Goudarzi M, Willard B, and Sharifi N
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- Male, Humans, Androgens metabolism, Receptors, Androgen genetics, Receptors, Androgen metabolism, Androgen Antagonists, Up-Regulation, Glucosamine, Multienzyme Complexes genetics, Cell Line, Tumor, Prostatic Neoplasms pathology, Prostatic Neoplasms, Castration-Resistant genetics, Cancer-Associated Fibroblasts metabolism
- Abstract
After androgen deprivation, prostate cancer frequently becomes castration resistant (CRPC), with intratumoral androgen production from extragonadal precursors that activate the androgen receptor pathway. 3β-Hydroxysteroid dehydrogenase-1 (3βHSD1) is the rate-limiting enzyme for extragonadal androgen synthesis, which together lead to CRPC. Here, we show that cancer-associated fibroblasts (CAFs) increased epithelial 3βHSD1 expression, induced androgen synthesis, activated the androgen receptor, and induced CRPC. Unbiased metabolomics revealed that CAF-secreted glucosamine specifically induced 3βHSD1. CAFs induced higher GlcNAcylation in cancer cells and elevated expression of the transcription factor Elk1, which induced higher 3βHSD1 expression and activity. Elk1 genetic ablation in cancer epithelial cells suppressed CAF-induced androgen biosynthesis in vivo. In patient samples, multiplex fluorescent imaging showed that tumor cells expressed more 3βHSD1 and Elk1 in CAF-enriched areas compared with CAF-deficient areas. Our findings suggest that CAF-secreted glucosamine increases GlcNAcylation in prostate cancer cells, promoting Elk1-induced HSD3B1 transcription, which upregulates de novo intratumoral androgen synthesis to overcome castration.
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- 2023
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13. Response to "Letter to the Editor From Penning and Deltefsen "5-hydroxyeicosatetraenoic Acid Controls Androgen Reduction in Diverse Types of Human Epithelial Cells".
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Hardaway AL, Goodarzi M, Berk M, Li J, Chung YM, and Sharifi N
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- Humans, Epithelial Cells, Androgens pharmacology, Hydroxyeicosatetraenoic Acids
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- 2023
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14. BMX controls 3βHSD1 and sex steroid biosynthesis in cancer.
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Li X, Berk M, Goins C, Alyamani M, Chung YM, Wang C, Patel M, Rathi N, Zhu Z, Willard B, Stauffer S, Klein E, and Sharifi N
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- Male, Humans, Androgens metabolism, Aromatase therapeutic use, Receptors, Androgen genetics, Receptors, Androgen metabolism, Testosterone therapeutic use, Protein-Tyrosine Kinases, Prostatic Neoplasms, Castration-Resistant metabolism, Prostatic Neoplasms metabolism
- Abstract
Prostate cancer is highly dependent on androgens and the androgen receptor (AR). Hormonal therapies inhibit gonadal testosterone production, block extragonadal androgen biosynthesis, or directly antagonize AR. Resistance to medical castration occurs as castration-resistant prostate cancer (CRPC) and is driven by reactivation of the androgen-AR axis. 3β-hydroxysteroid dehydrogenase-1 (3βHSD1) serves as the rate-limiting step for potent androgen synthesis from extragonadal precursors, thereby stimulating CRPC. Genetic evidence in men demonstrates the role of 3βHSD1 in driving CRPC. In postmenopausal women, 3βHSD1 is required for synthesis of aromatase substrates and plays an essential role in breast cancer. Therefore, 3βHSD1 lies at a critical junction for the synthesis of androgens and estrogens, and this metabolic flux is regulated through germline-inherited mechanisms. We show that phosphorylation of tyrosine 344 (Y344) occurs and is required for 3βHSD1 cellular activity and generation of Δ4, 3-keto-substrates of 5α-reductase and aromatase, including in patient tissues. BMX directly interacts with 3βHSD1 and is necessary for enzyme phosphorylation and androgen biosynthesis. In vivo blockade of 3βHSD1 Y344 phosphorylation inhibits CRPC. These findings identify what we believe to be new hormonal therapy pharmacologic vulnerabilities for sex-steroid dependent cancers.
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- 2023
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15. 5-Hydroxyeicosatetraenoic Acid Controls Androgen Reduction in Diverse Types of Human Epithelial Cells.
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Hardaway AL, Goudarzi M, Berk M, Chung YM, Zhang R, Li J, Klein E, and Sharifi N
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- Male, Humans, Aldo-Keto Reductase Family 1 Member C3 metabolism, Hydroxyeicosatetraenoic Acids, Epithelial Cells metabolism, Androgens metabolism, Prostatic Neoplasms metabolism
- Abstract
Androgens regulate broad physiologic and pathologic processes, including external genitalia development, prostate cancer progression, and anti-inflammatory effects in both cancer and asthma. In prostate cancer, several lines of evidence have implicated dietary and endogenous fatty acids in cell invasion, angiogenesis, and treatment resistance. However, the role of fatty acids in steroidogenesis and the mechanisms by which alterations in this pathway occur are not well understood. Here, we show that, of a panel of fatty acids tested, arachidonic acid and its specific metabolite 5-hydroxyeicosatetraenoic acid (5-HETE) regulate androgen metabolism. Arachidonic acid is metabolized to 5-HETE and reduces androgens by inducing aldo-keto reductase (AKR) family members AKR1C2 and AKR1C3 expression in human prostate, breast, and lung epithelial cells. Finally, we provide evidence that these effects require the expression of the antioxidant response sensor, nuclear factor erythroid 2-related factor 2 (Nrf2). Our findings identify an interconnection between conventional fatty acid metabolism and steroid metabolism that has broad relevance to androgen physiology and inflammatory regulation., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2022
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16. Promoter hypomethylation and overexpression of TSTD1 mediate poor treatment response in breast cancer.
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Ansar M, Thu LTA, Hung CS, Su CM, Huang MH, Liao LM, Chung YM, and Lin RK
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Epigenetic alterations play a pivotal role in cancer treatment outcomes. Using the methylation array data and The Cancer Genome Atlas (TCGA) dataset, we observed the hypomethylation and upregulation of thiosulfate sulfurtransferase-like domain containing 1 ( TSTD1 ) in patients with breast cancer. We examined paired tissues from Taiwanese patients and observed that 65.09% and 68.25% of patients exhibited TSTD1 hypomethylation and overexpression, respectively. A significant correlation was found between TSTD1 hypomethylation and overexpression in Taiwanese (74.2%, p = 0.040 ) and Western (88.0%, p < 0.001 ) cohorts. High expression of TSTD1 protein was observed in 68.8% of Taiwanese and Korean breast cancer patients. Overexpression of TSTD1 in tumors of breast cancer patients was significantly associated with poor 5-year overall survival ( p = 0.021) and poor chemotherapy response ( p = 0.008). T47D cells treated with TSTD1 siRNA exhibited lower proliferation than the control group, and transfection of TSTD1 in MDA-MB-231 induced the growth of MDA-MB-231 cells compared to the vector control. Additionally, overexpression of TSTD1 in MCF7 cells mediated a poor response to chemotherapy by epirubicin ( p < 0.001) and docetaxel ( p < 0.001) and hormone therapy by tamoxifen ( p =0.025). Circulating cell-free hypomethylated TSTD1 was detected in plasma of Taiwanese breast cancer patients with disease progression and poor chemotherapy efficacy. Our results indicate that promoter hypomethylation and overexpression of TSTD1 in patients with breast cancer are potential biomarkers for poor 5-year overall survival and poor treatment response., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Ansar, Thu, Hung, Su, Huang, Liao, Chung and Lin.)
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- 2022
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17. Numerical model for cough-generated droplet dispersion on moving escalator with multiple passengers.
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Takii A, Yamakawa M, Kitagawa A, Watamura T, Chung YM, and Kim M
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- Humans, Cough, Computer Simulation, Movement, Elevators and Escalators, Air Pollution, Indoor
- Abstract
To investigate the motion of virus-laden droplets between moving passengers in line, we performed numerical simulations of the distribution of airborne droplets within a geometrically detailed model similar to an actual escalator. The left and right sides and the ceiling of the escalator model were surrounded by walls, assuming a subway used by many people every day with concern to virus-laden droplets. Steps and handrails were incorporated in the model to faithfully compute the escalator-specific flow field. The ascending and descending movements of the escalator were performed with 10 or 5 passengers standing at different boarding intervals. To resolve the unsteady airflow that is excited by a moving boundary consisting of passengers, steps, and handrails, the moving computational domain method based on the moving-grid finite-volume method was applied. On the basis of the consideration that the droplets were small enough, droplet dispersion was computed by solving the equation of virus-laden droplet motion using a pre-computed velocity field, in which the flow rate of a cough, diameter distribution, and evaporation of droplets are incorporated. The simulation resolved the detailed motion of droplets in flow, and therefore, we were able to evaluate the risk of viral adhesion to following passengers. As a result, we found that the ascending escalator had a higher risk of being exposed to virus-laden droplets than the descending escalator. We also reported that the chance of viral droplet adhesion decreases as the distance from the infected person increases, emphasizing the importance of social distancing., (© 2022 The Authors. Indoor Air published by John Wiley & Sons Ltd.)
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- 2022
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18. Hypoxia-Reoxygenation Couples 3βHSD1 Enzyme and Cofactor Upregulation to Facilitate Androgen Biosynthesis and Hormone Therapy Resistance in Prostate Cancer.
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Qin L, Chung YM, Berk M, Naelitz B, Zhu Z, Klein E, Chakraborty AA, and Sharifi N
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- Androgen Antagonists pharmacology, Androgen Antagonists therapeutic use, Androgens metabolism, Cell Line, Tumor, Humans, Hypoxia, Male, Receptors, Androgen metabolism, Testosterone, Up-Regulation, Prostatic Neoplasms metabolism, Prostatic Neoplasms, Castration-Resistant pathology
- Abstract
Androgen deprivation therapy suppresses tumor androgen receptor (AR) signaling by depleting circulating testosterone and is a mainstay treatment for advanced prostate cancer. Despite initial treatment response, castration-resistant prostate cancer nearly always develops and remains driven primarily by the androgen axis. Here we investigated how changes in oxygenation affect androgen synthesis. In prostate cancer cells, chronic hypoxia coupled to reoxygenation resulted in efficient metabolism of androgen precursors to produce androgens and activate AR. Hypoxia induced 3βHSD1, the rate-limiting androgen synthesis regulator, and reoxygenation replenished necessary cofactors, suggesting that hypoxia and reoxygenation both facilitate potent androgen synthesis. The EGLN1/VHL/HIF2α pathway induced 3βHSD1 expression through direct binding of HIF2α to the 5' regulatory region of HSD3B1 to promote transcription. Overexpression of HIF2α facilitated prostate cancer progression, which largely depended on 3βHSD1. Inhibition of HIF2α with the small-molecule PT2399 prevented prostate cancer cell proliferation. These results thus identify HIF2α as a regulator of androgen synthesis and potential therapeutic target in prostate cancer., Significance: Hypoxia followed by reoxygenation in prostate cancer drives androgen deprivation therapy resistance via increasing the rate-limiting enzyme and cofactors for androgen synthesis, revealing HIF2α as a therapeutic target to subvert resistance., (©2022 American Association for Cancer Research.)
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- 2022
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19. A multi-parameter persistence framework for mathematical morphology.
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Chung YM, Day S, and Hu CS
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- Image Processing, Computer-Assisted methods
- Abstract
The field of mathematical morphology offers well-studied techniques for image processing and is applicable for studies ranging from materials science to ecological pattern formation. In this work, we view morphological operations through the lens of persistent homology, a tool at the heart of the field of topological data analysis. We demonstrate that morphological operations naturally form a multiparameter filtration and that persistent homology can then be used to extract information about both topology and geometry in the images as well as to automate methods for optimizing the study and rendering of structure in images. For illustration, we develop an automated approach that utilizes this framework to denoise binary, grayscale, and color images with salt and pepper and larger spatial scale noise. We measure our example unsupervised denoising approach to state-of-the-art supervised, deep learning methods to show that our results are comparable., (© 2022. The Author(s).)
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- 2022
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20. FOXO3-dependent suppression of PD-L1 promotes anticancer immune responses via activation of natural killer cells.
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Chung YM, Tsai WB, Khan PP, Ma J, Berek JS, Larrick JW, and Hu MC
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Boosting anticancer immunity by blocking immune checkpoints such as the programmed death-1 (PD-1) or its ligand (PD-L1) is a breakthrough anticancer therapy. However, many cancer patients do not respond well to immune checkpoint blockades (ICBs) alone. Here we show that low-dose pharmacological immunoactivators (e.g., SN38, topotecan, sorafenib, etc.) notably downregulate PD-L1 and upregulate FOXO3 expression in various human and murine cancer cell lines. In a mouse tumor model, low-dose SN38 treatment markedly suppresses tumor growth, reduces PD-L1 expression, and enhances FOXO3 expression in primary tumor specimens. SN38 therapy engages the tumor-infiltrating mouse NK1.1/CD49b/NKG2D-positive natural killer (NK) cells to attack tumor cells by inducing mouse IFN-γ and granzyme-B secretion in the tumor microenvironment (TME) in vivo . SN38 treatment also promotes tumor cell apoptosis in the TME. SN38 treatment significantly decreases STAT3-pY705 and IL-6 protein levels; FOXO3 is essential for SN38-mediated PD-L1 downregulation. Collectively, these findings may contribute to future translational or clinical investigations tackling difficult-to-treat cancers with immune-activating medicines or combined with ICB immunotherapy., Competing Interests: None., (AJCR Copyright © 2022.)
- Published
- 2022
21. Sensitizing tumors to anti-PD-1 therapy by promoting NK and CD8+ T cells via pharmacological activation of FOXO3.
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Chung YM, Khan PP, Wang H, Tsai WB, Qiao Y, Yu B, Larrick JW, and Hu MC
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- Animals, Apoptosis, B7-H1 Antigen antagonists & inhibitors, B7-H1 Antigen metabolism, Breast Neoplasms immunology, Breast Neoplasms metabolism, Breast Neoplasms pathology, Carcinoma, Hepatocellular immunology, Carcinoma, Hepatocellular metabolism, Carcinoma, Hepatocellular pathology, Cell Proliferation, Female, Forkhead Box Protein O3 genetics, Gene Expression Regulation, Neoplastic drug effects, Humans, Immunotherapy, Irinotecan pharmacology, Liver Neoplasms drug therapy, Liver Neoplasms immunology, Liver Neoplasms metabolism, Liver Neoplasms pathology, Mice, Mice, Inbred C57BL, Ovarian Neoplasms immunology, Ovarian Neoplasms metabolism, Ovarian Neoplasms pathology, Prognosis, Programmed Cell Death 1 Receptor antagonists & inhibitors, Topoisomerase I Inhibitors pharmacology, Tumor Cells, Cultured, Tumor Microenvironment, Breast Neoplasms drug therapy, CD8-Positive T-Lymphocytes immunology, Carcinoma, Hepatocellular drug therapy, Forkhead Box Protein O3 metabolism, Immune Checkpoint Inhibitors pharmacology, Killer Cells, Natural immunology, Ovarian Neoplasms drug therapy
- Abstract
Background: Stimulating antitumor immunity by blocking programmed death-1 (PD-1) or its ligand (programmed death-ligand 1 (PD-L1) is a promising antitumor therapy. However, numerous patients respond poorly to PD-1/PD-L1 blockade. Unresponsiveness to immune-checkpoint blockade (ICB) can cast significant challenges to the therapeutic options for patients with hard-to-treat tumors. There is an unmet clinical need to establish new therapeutic approaches for mitigating ICB unresponsiveness in patients. In this study, we investigated the efficacy and role of low-dose antineoplastic agent SN-38 or metformin in sensitizing unresponsive tumors to respond to ICB therapy., Methods: We assessed the significant pathological relationships between PD-L1 and FOXO3 expression and between PD-L1 and c-Myc or STAT3 expression in patients with various tumors. We determined the efficacy of low-dose SN-38 or metformin in sensitizing unresponsive tumors to respond to anti-PD-1 therapy in a syngeneic tumor system. We deciphered novel therapeutic mechanisms underlying the SN-38 and anti-PD-1 therapy-mediated engagement of natural killer (NK) or CD8+ T cells to infiltrate tumors and boost antitumor immunity., Results: We showed that PD-L1 protein level was inversely associated with FOXO3 protein level in patients with ovarian, breast, and hepatocellular tumors. Low-dose SN-38 or metformin abrogated PD-L1 protein expression, promoted FOXO3 protein level, and significantly increased the animal survival rate in syngeneic mouse tumor models. SN-38 or metformin sensitized unresponsive tumors responding to anti-PD-1 therapy by engaging NK or CD8+ T cells to infiltrate the tumor microenvironment (TME) and secret interferon-γ and granzyme B to kill tumors. SN-38 suppressed the levels of c-Myc and STAT3 proteins, which controlled PD-L1 expression. FOXO3 was essential for SN38-mediated PD-L1 suppression. The expression of PD-L1 was compellingly linked to that of c-Myc or STAT3 in patients with the indicated tumors., Conclusion: We show that SN-38 or metformin can boost antitumor immunity in the TME by inhibiting c-Myc and STAT3 through FOXO3 activation. These results may provide novel insight into ameliorating patient response to overarching immunotherapy for tumors., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2021
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22. Adrenal-permissive HSD3B1 genetic inheritance and risk of estrogen-driven postmenopausal breast cancer.
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Kruse ML, Patel M, McManus J, Chung YM, Li X, Wei W, Bazeley PS, Nakamura F, Hardaway A, Downs E, Chandarlapaty S, Thomas M, Moore HC, Budd GT, Tang WHW, Hazen SL, Bernstein A, Nik-Zainal S, Abraham J, and Sharifi N
- Subjects
- Estrogens pharmacology, Female, Humans, Postmenopause, Prospective Studies, Risk Factors, Breast Neoplasms genetics, Breast Neoplasms physiopathology, Estrogens therapeutic use, Multienzyme Complexes metabolism, Progesterone Reductase metabolism, Steroid Isomerases metabolism
- Abstract
BACKGROUNDGenetics of estrogen synthesis and breast cancer risk has been elusive. The 1245A→C missense-encoding polymorphism in HSD3B1, which is common in White populations, is functionally adrenal permissive and increases synthesis of the aromatase substrate androstenedione. We hypothesized that homozygous inheritance of the adrenal-permissive HSD3B1(1245C) is associated with postmenopausal estrogen receptor-positive (ER-positive) breast cancer.METHODSA prospective study of postmenopausal ER-driven breast cancer was done for determination of HSD3B1 and circulating steroids. Validation was performed in 2 other cohorts. Adrenal-permissive genotype frequency was compared between postmenopausal ER-positive breast cancer, the general population, and postmenopausal ER-negative breast cancer.RESULTSProspective and validation studies had 157 and 538 patients, respectively, for the primary analysis of genotype frequency by ER status in White female breast cancer patients who were postmenopausal at diagnosis. The adrenal-permissive genotype frequency in postmenopausal White women with estrogen-driven breast cancer in the prospective cohort was 17.5% (21/120) compared with 5.4% (2/37) for ER-negative breast cancer (P = 0.108) and 9.6% (429/4451) in the general population (P = 0.0077). Adrenal-permissive genotype frequency for estrogen-driven postmenopausal breast cancer was validated using Cambridge and The Cancer Genome Atlas data sets: 14.4% (56/389) compared with 6.0% (9/149) for ER-negative breast cancer (P = 0.007) and the general population (P = 0.005). Circulating androstenedione concentration was higher with the adrenal-permissive genotype (P = 0.03).CONCLUSIONAdrenal-permissive genotype is associated with estrogen-driven postmenopausal breast cancer. These findings link genetic inheritance of endogenous estrogen exposure to estrogen-driven breast cancer.FUNDINGNational Cancer Institute, NIH (R01CA236780, R01CA172382, and P30-CA008748); and Prostate Cancer Foundation Challenge Award.
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- 2021
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23. Determination of Residual Triflumezopyrim Insecticide in Agricultural Products through a Modified QuEChERS Method.
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Cho SM, Lee HS, Park JS, Lee SJ, Shin HS, Chung YM, Choi HN, Jung YH, Oh JH, and Yun SS
- Abstract
A rapid and simple analytical method for triflumezopyrim, a new class of mesoionic insecticides and commercialized molecules from DuPont, was developed with a modified QuEChERS method. The pH adjustment was used to improve the extraction efficiency of acetonitrile solvent, and dispersive solid-phase extraction was employed for the clean-up process. The five selected food commodities were used to verify the present optimized method, which displayed good linearity with an excellent correlation coefficient ( R
2 = 0.9992-0.9998) in the 0.003-0.30 mg/kg calibration range. The method limits of detection (LOD) and quantification (LOQ) were determined to be a value of 0.003 and 0.01 mg/kg, respectively. The mean recovery for the triflumezopyrim was in the 89.7-104.3% range. The relative standard deviations were ≤9.8% for intra- ( n = 5) and inter-day ( n = 15) precisions at concentrations of 0.01, 0.1, and 0.5 mg/kg in the five representative samples. The matrix effect has been calculated to confirm the effect during ionization of the analyte in the UPLC-MS/MS. The matrix effects of the instrumental analysis showed that triflumezopyrim was less susceptible to matrices. The proposed analytical method in this study has effectively improved the accuracy, selectivity, and sensitivity for the determination of triflumezopyrim in agricultural commodities; therefore, it can serve as a reference method for the establishment of maximum residue limits (MRLs).- Published
- 2021
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24. Computational investigation of prolonged airborne dispersion of novel coronavirus-laden droplets.
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Yamakawa M, Kitagawa A, Ogura K, Chung YM, and Kim M
- Abstract
We have performed highly accurate numerical simulations to investigate prolonged dispersion of novel coronavirus-laden droplets in classroom air. Approximately 10,900 virus-laden droplets were released into the air by a teacher coughing and tracked for 90 min by numerical simulations. The teacher was standing in front of multiple students in a classroom. To estimate viral transmission to the students, we considered the features of the novel coronavirus, such as the virus half-life. The simulation results revealed that there was a high risk of prolonged airborne transmission of virus-laden droplets when the outlet flow of the classroom ventilation was low (i.e., 4.3 and 8.6 cm/s). The rates of remaining airborne virus-laden droplets produced by the teacher coughing were 40% and 15% after 45 and 90 min, respectively. The results revealed that students can avoid exposure to the virus-laden droplets by keeping a large distance from the teacher (5.5 m), which is more than two times farther than the currently suggested social distancing rules. The results of this study provide guidelines to set a new protection plan in the classroom to prevent airborne transmission of virus-laden droplets to students., Competing Interests: There is no conflict of interest in this paper., (© 2021 The Authors.)
- Published
- 2021
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25. The potential of immature poken ( Citrus reticulata ) extract in the weight management, lipid and glucose metabolism.
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Lin YK, Chung YM, Yang HT, Lin YH, Lin YH, Hu WC, and Chiang CF
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- Blood Glucose metabolism, Body Mass Index, Body Weight, Glucose therapeutic use, Humans, Lipid Metabolism, Obesity, Plant Extracts pharmacology, Plant Extracts therapeutic use, Triglycerides, Citrus chemistry
- Abstract
Objectives: The prevalence of obesity was increasing globally, with nearly half a billion of the world's population now considered to be overweight or obese. The immature poken ( Citrus reticulata ) was a good source of flavonoids and phenolic acids, which may exert an anti-obesity effect. However, the current efficacy in clinical trials was still unclear. Thus, the object of this study was to explore whether immature poken had an anti-obesity effect in the clinical trial., Methods: In this study, we identified nine major compounds from immature poken extract (IPE), and most compounds significantly decreased the lipid accumulation in adipocytes. In addition, 20 subjects with body mass index (BMI) ≥ 24 or body fat > 30 were recruited and randomly allocated to placebo and experimental (IPE) groups for 6 week intervention and 2 week follow-up., Results: In comparison with the baseline results (week 0), the body weight, body fat, and waist circumference at week 6 in the IPE group were significantly decreased by 1.49 kg, 0.33%, 2.1 cm. Moreover, in blood biochemical analysis, total cholesterol (TC), triglyceride (TG), fasting blood sugar (FBS), and insulin levels at week 6 in IPE group were also decreased by 3.6, 4.6, 2.1 (mg/dL), and 2.9 (μU/mL), respectively., Conclusions: The finding showed that immature poken had important roles in fat metabolism by suppressing adipogenesis, and immature poken may provide new weight loss strategies for obese people., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)
- Published
- 2021
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26. Automatic Detection of the Circulating Cell-Free Methylated DNA Pattern of GCM2 , ITPRIPL1 and CCDC181 for Detection of Early Breast Cancer and Surgical Treatment Response.
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Wang SC, Liao LM, Ansar M, Lin SY, Hsu WW, Su CM, Chung YM, Liu CC, Hung CS, and Lin RK
- Abstract
The early detection of cancer can reduce cancer-related mortality. There is no clinically useful noninvasive biomarker for early detection of breast cancer. The aim of this study was to develop accurate and precise early detection biomarkers and a dynamic monitoring system following treatment. We analyzed a genome-wide methylation array in Taiwanese and The Cancer Genome Atlas (TCGA) breast cancer (BC) patients. Most breast cancer-specific circulating methylated CCDC181 , GCM2 and ITPRIPL1 biomarkers were found in the plasma. An automatic analysis process of methylated ccfDNA was established. A combined analysis of CCDC181 , GCM2 and ITPRIPL1 (CGIm) was performed in R using Recursive Partitioning and Regression Trees to establish a new prediction model. Combined analysis of CCDC181 , GCM2 and ITPRIPL1 (CGIm) was found to have a sensitivity level of 97% and an area under the curve (AUC) of 0.955 in the training set, and a sensitivity level of 100% and an AUC of 0.961 in the test set. The circulating methylated CCDC181 , GCM2 and ITPRIPL1 was also significantly decreased after surgery (all p < 0.001). The aberrant methylation patterns of the CCDC181 , GCM2 and ITPRIPL1 genes means that they are potential biomarkers for the detection of early BC and can be combined with breast imaging data to achieve higher accuracy, sensitivity and specificity, facilitating breast cancer detection. They may also be applied to monitor the surgical treatment response.
- Published
- 2021
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27. A Persistent Homology Approach to Heart Rate Variability Analysis With an Application to Sleep-Wake Classification.
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Chung YM, Hu CS, Lo YL, and Wu HT
- Abstract
Persistent homology is a recently developed theory in the field of algebraic topology to study shapes of datasets. It is an effective data analysis tool that is robust to noise and has been widely applied. We demonstrate a general pipeline to apply persistent homology to study time series, particularly the instantaneous heart rate time series for the heart rate variability (HRV) analysis. The first step is capturing the shapes of time series from two different aspects-the persistent homologies and hence persistence diagrams of its sub-level set and Taken's lag map. Second, we propose a systematic and computationally efficient approach to summarize persistence diagrams, which we coined persistence statistics . To demonstrate our proposed method, we apply these tools to the HRV analysis and the sleep-wake, REM-NREM (rapid eyeball movement and non rapid eyeball movement) and sleep-REM-NREM classification problems. The proposed algorithm is evaluated on three different datasets via the cross-database validation scheme. The performance of our approach is better than the state-of-the-art algorithms, and the result is consistent throughout different datasets., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Chung, Hu, Lo and Wu.)
- Published
- 2021
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28. Uptake of high-density lipoprotein by scavenger receptor class B type 1 is associated with prostate cancer proliferation and tumor progression in mice.
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Traughber CA, Opoku E, Brubaker G, Major J, Lu H, Lorkowski SW, Neumann C, Hardaway A, Chung YM, Gulshan K, Sharifi N, Brown JM, and Smith JD
- Subjects
- Animals, Cell Line, Tumor, Cell Proliferation, Cholesterol metabolism, Gene Expression Regulation, Neoplastic, Humans, Male, Mice, Inbred C57BL, Prostatic Neoplasms genetics, Up-Regulation genetics, Disease Progression, Lipoproteins, HDL metabolism, Prostatic Neoplasms metabolism, Prostatic Neoplasms pathology, Scavenger Receptors, Class B metabolism
- Abstract
High-density lipoprotein (HDL) metabolism is facilitated in part by scavenger receptor class B, type 1 (SR-B1) that mediates HDL uptake into cells. Higher levels of HDL have been associated with protection in other diseases, however, its role in prostate cancer is not definitive. SR-B1 is up-regulated in prostate cancer tissue, suggesting a possible role of this receptor in tumor progression. Here, we report that knockout (KO) of SR-B1 in both human and mouse prostate cancer cell lines through CRISPR/Cas9-mediated genome editing reduces HDL uptake into the prostate cancer cells and reduces their proliferation in response to HDL. In vivo studies using syngeneic SR-B1 WT (SR-B1
+/+ ) and SR-B1 KO (SR-B1-/- ) prostate cancer cells in WT and apolipoprotein-AI KO (apoA1-KO) C57BL/6J mice revealed that WT hosts, containing higher levels of total and HDL-cholesterol, grew larger tumors than apoA1-KO hosts with lower levels of total and HDL-cholesterol. Furthermore, SR-B1-/- prostate cancer cells formed smaller tumors in WT hosts than SR-B1+/+ cells in the same host model. Increased tumor volume was overall associated with reduced survival. We conclude that knocking out SR-B1 in prostate cancer tumors reduces HDL-associated increases in prostate cancer cell proliferation and disease progression., Competing Interests: Conflict of interest—N. S. has been a paid advisor to Celgene., (© 2020 Traughber et al.)- Published
- 2020
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29. Rapid and structure-specific cellular uptake of selected steroids.
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McManus JM, Bohn K, Alyamani M, Chung YM, Klein EA, and Sharifi N
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- Androgens analysis, Androgens blood, Androgens metabolism, Cell Line, Tumor, Cell Survival drug effects, Chromatography, High Pressure Liquid, Dehydroepiandrosterone analysis, Dehydroepiandrosterone metabolism, Humans, Kinetics, Pregnenolone analysis, Pregnenolone metabolism, Progesterone analysis, Progesterone metabolism, Progesterone pharmacology, Steroids analysis, Steroids pharmacology, Tandem Mass Spectrometry, Steroids metabolism
- Abstract
Steroid hormones and their respective nuclear receptors are essential mediators in numerous physiologic and pathophysiologic processes, ranging from regulation of metabolism, immune function, and reproductive processes to the development of hormone-dependent cancers such as those of the breast and prostate. Because steroids must enter cells before activating nuclear receptors, understanding the mechanisms by which cellular uptake occurs is critical, yet a clear understanding of these mechanisms has been elusive. It is generally assumed that diffusion-driven uptake is similar across various steroids whereas an elevated cellular concentration is thought to reflect active uptake, but these assumptions have not been directly tested. Here we show that intact cells rapidly accumulate free steroids to markedly elevated concentrations. This effect varies widely depending on steroid structure; more lipophilic steroids reach more elevated concentrations. Strong preferences exist for 3β-OH, Δ5-steroids vs. 3-keto, Δ4-structural features and for progestogens vs. androgens. Surprisingly, steroid-structure-specific preferences do not require cell viability, implying a passive mechanism, and occur across cells derived from multiple tissue types. Physiologic relevance is suggested by structure-specific preferences in human prostate tissue compared with serum. On the other hand, the presence of serum proteins in vitro blocks much, but not all, of the passive accumulation, while still permitting a substantial amount of active accumulation for certain steroids. Our findings suggest that both passive and active uptake mechanisms make important contributions to the cellular steroid uptake process. The role of passive, lipophilicity-driven accumulation has previously been largely unappreciated, and its existence provides important context to studies on steroid transport and action both in vitro and in vivo., Competing Interests: The authors have declared that no competing interests exist
- Published
- 2019
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30. Trimethyllysine, a trimethylamine N-oxide precursor, provides near- and long-term prognostic value in patients presenting with acute coronary syndromes.
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Li XS, Obeid S, Wang Z, Hazen BJ, Li L, Wu Y, Hurd AG, Gu X, Pratt A, Levison BS, Chung YM, Nissen SE, Tang WHW, Mach F, Räber L, Nanchen D, Matter CM, Lüscher TF, and Hazen SL
- Subjects
- Aged, Female, Humans, Lysine blood, Male, Methylamines blood, Middle Aged, Prognosis, Prospective Studies, Acute Coronary Syndrome blood, Acute Coronary Syndrome diagnosis, Acute Coronary Syndrome epidemiology, Acute Coronary Syndrome mortality, Lysine analogs & derivatives
- Abstract
Aims: Trimethyllysine (TML) serves as a nutrient precursor of the gut microbiota-derived metabolite trimethylamine N-oxide (TMAO) and is associated with incident cardiovascular (CV) events in stable subjects. We examined the relationship between plasma TML levels and incident CV events in patients presenting with acute coronary syndromes (ACS)., Methods and Results: Plasma levels of TML were quantified in two independent cohorts using mass spectrometry, and its relationship with CV events was investigated. In a Cleveland Cohort (N = 530), comprised of patients presenting to the emergency department with chest pain and suspected ACS, TML was associated with major adverse cardiac events (MACE, myocardial infarction, stroke, need for revascularization, or all-cause mortality) over both 30 days [3rd tertile (T3), adjusted odds ratio (OR) 1.77, 95% confidence interval (CI) 1.04-3.01; P < 0.05] and 6 months (T3, adjusted OR 1.95, 95% CI 1.15-3.32; P < 0.05) of follow-up independent of traditional CV risk factors and indices of renal function. Elevated TML levels were also associated with incident long-term (7-year) all-cause mortality [T3, adjusted hazard ratio (HR) 2.52, 95% CI 1.50-4.24; P < 0.001], and MACE even amongst patients persistently negative for cardiac Troponin T at presentation (e.g. 30-day MACE, T3, adjusted OR 4.49, 95% CI 2.06-9.79; P < 0.001). Trimethyllysine in combination with TMAO showed additive significance for near- and long-term CV events, including patients with 'negative' high-sensitivity Troponin T levels. In a multicentre Swiss Cohort (N = 1683) comprised of ACS patients, similar associations between TML and incident 1-year adverse cardiac risks were observed (e.g. mortality, adjusted T3 HR 2.74, 95% CI 1.28-5.85; P < 0.05; and MACE, adjusted T3 HR 1.55, 95% CI 1.04-2.31; P < 0.05)., Conclusion: Plasma TML levels, alone and together with TMAO, are associated with both near- and long-term CV events in patients with chest pain and ACS., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2019
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31. Dose-dependent and strain-dependent anti-obesity effects of Lactobacillus sakei in a diet induced obese murine model.
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Ji Y, Chung YM, Park S, Jeong D, Kim B, and Holzapfel WH
- Abstract
Background: Overweight and abdominal obesity, in addition to medical conditions such as high blood pressure, high blood sugar and triglyceride levels, are typical risk factors associated with metabolic syndrome. Yet, considering the complexity of factors and underlying mechanisms leading to these inflammatory conditions, a deeper understanding of this area is still lacking. Some probiotics have a reputation of a relatively-long history of safe use, and an increasing number of studies are confirming benefits including anti-obesity effects when administered in adequate amounts. Recent reports demonstrate that probiotic functions may widely differ with reference to either intra-species or inter-species related data. Such differences do not necessarily reflect or explain strain-specific functions of a probiotic, and thus require further assessment at the intra-species level. Various anti-obesity clinical trials with probiotics have shown discrepant results and require additional consolidated studies in order to clarify the correct dose of application for reliable and constant efficacy over a long period., Methods: Three different strains of Lactobacillus sakei were administered in a high-fat diet induced obese murine model using three different doses, 1 × 10
10 , 1 × 109 and 1 × 108 CFUs, respectively, per day. Changes in body and organ weight were monitored, and serum chemistry analysis was performed for monitoring obesity associated biomarkers., Results: Only one strain of L. sakei (CJLS03) induced a dose-dependent anti-obesity effect, while no correlation with either dose or body or adipose tissue weight loss could be detected for the other two L. sakei strains (L338 and L446). The body weight reduction primarily correlated with adipose tissue and obesity-associated serum biomarkers such as triglycerides and aspartate transaminase., Discussion: This study shows intraspecies diversity of L. sakei and suggests that anti-obesity effects of probiotics may vary in a strain- and dose-specific manner., Competing Interests: Yosep Ji, Soyoung Park and Wilhelm H Holzapfel have received research grants, via Handong Global University, from CJ CheilJedang Corporation, South Korea. Co-authors Young Mee Chung, Dahye Jeong and Bongjoon Kim are employed by CJ CheilJedang Corp., Blossom Park, Republic of Korea.- Published
- 2019
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32. Loss of dihydrotestosterone-inactivation activity promotes prostate cancer castration resistance detectable by functional imaging.
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Zhu Z, Chung YM, Sergeeva O, Kepe V, Berk M, Li J, Ko HK, Li Z, Petro M, DiFilippo FP, Lee Z, and Sharifi N
- Subjects
- Animals, Cell Line, Tumor, Dihydrotestosterone chemistry, Fluorine Radioisotopes, Glucuronosyltransferase genetics, Glucuronosyltransferase metabolism, Glycosylation, Humans, Male, Mice, Minor Histocompatibility Antigens genetics, Minor Histocompatibility Antigens metabolism, Positron-Emission Tomography, Radiopharmaceuticals chemistry, Receptors, Androgen physiology, Signal Transduction, Testosterone chemistry, Dihydrotestosterone metabolism, Prostatic Neoplasms, Castration-Resistant diagnostic imaging, Prostatic Neoplasms, Castration-Resistant metabolism, Testosterone metabolism
- Abstract
Androgens such as testosterone and dihydrotestosterone are a critical driver of prostate cancer progression. Cancer resistance to androgen deprivation therapies ensues when tumors engage metabolic processes that produce sustained androgen levels in the tissue. However, the molecular mechanisms involved in this resistance process are unclear, and functional imaging modalities that predict impending resistance are lacking. Here, using the human LNCaP and C4-2 cell line models of prostate cancer, we show that castration treatment-sensitive prostate cancer cells that normally have an intact glucuronidation pathway that rapidly conjugates and inactivates dihydrotestosterone and thereby limits androgen signaling, become glucuronidation deficient and resistant to androgen deprivation. Mechanistically, using CRISPR/Cas9-mediated gene ablation, we found that loss of UDP glucuronosyltransferase family 2 member B15 (UGT2B15) and UGT2B17 is sufficient to restore free dihydrotestosterone, sustained androgen signaling, and development of castration resistance. Furthermore, loss of glucuronidation enzymatic activity was also detectable with a nonsteroid glucuronidation substrate. Of note, glucuronidation-incompetent cells and the resultant loss of intracellular conjugated dihydrotestosterone were detectable in vivo by
18 F-dihydrotestosterone PET. Together, these findings couple a mechanism with a functional imaging modality to identify impending castration resistance in prostate cancers., (© 2018 Zhu et al.)- Published
- 2018
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33. Effect of upper airway on tracheobronchial fluid dynamics.
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Kim M, Collier GJ, Wild JM, and Chung YM
- Subjects
- Computer Simulation, Female, Humans, Larynx diagnostic imaging, Magnetic Resonance Imaging, Middle Aged, Respiratory Tract Infections diagnostic imaging, Respiratory Tract Infections physiopathology, Tomography, X-Ray Computed, Trachea diagnostic imaging, Hydrodynamics, Larynx physiology, Trachea physiology
- Abstract
The upper airways play a significant role in the tracheal flow dynamics. Despite many previous studies, however, the effect of the upper airways on the ventilation distribution in distal airways has remained a challenge. The aim of this study is to experimentally and computationally investigate the dynamic behaviour in the intratracheal flow induced by the upper respiratory tract and to assess its influence on the subsequent tributaries. Patient-specific images from 2 different modalities (magnetic resonance imaging of the upper airways and computed tomography of the lower airways) were segmented and combined. An experimental phantom of patient-specific airways (including the oral cavity, larynx, trachea, down to generations 6-8) was generated using 3D printing. The flow velocities in this phantom model were measured by the flow-sensitised phase contrast magnetic resonance imaging technique and compared with the computational fluid dynamics simulations. Both experimental and computational results show a good agreement in the time-averaged velocity fields as well as fluctuating velocity. The flows in the proximal trachea were complex and unsteady under both lower- and higher-flow rate conditions. Computational fluid dynamics simulations were also performed with an airways model without the upper airways. Although the flow near the carina remained unstable only when the inflow rate was high, the influence of the upper airways caused notable changes in distal flow distributions when the 2 airways models were compared with and without the upper airways. The results suggest that the influence of the upper airways should be included in the respiratory flow assessment as the upper airways extensively affect the flows in distal airways and consequent ventilation distribution in the lungs., (© 2018 John Wiley & Sons, Ltd.)
- Published
- 2018
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34. Epidemiology of Behcet's Disease in Taiwan: A Population-Based Study.
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Lin YH, Tai TY, Pu CY, Hwang DK, Chung YM, and Chou YJ
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- Adolescent, Adult, Age Distribution, Aged, Aged, 80 and over, Child, Child, Preschool, Female, Humans, Incidence, Infant, Infant, Newborn, Male, Middle Aged, Retrospective Studies, Risk Factors, Sex Distribution, Taiwan epidemiology, Young Adult, Behcet Syndrome epidemiology, Risk Assessment methods
- Abstract
Purpose: To study the incidence and epidemiology of Behcet's disease in Taiwan., Methods: This retrospective cohort study was conducted using the nationwide reimbursement database in Taiwan. One million registered beneficiaries of the Taiwan National Health Insurance system in 2000 were randomly selected. All medical claims of these persons were collected. The definition of having Behcet's disease was based on diagnostic codes. Persons who had incomplete registry data or diagnoses prior to 2001 were excluded. Annual incidence between 2001 and 2011 was calculated and risk factors for incidence were explored using the Cox proportional regression model. Characteristics of patients with Behcet's disease with and without uveitis were compared., Results: A total of 236 newly diagnosed patients with Behcet's disease were found between 2001 and 2011. The average incidence was 2.40 cases per 100,000 person-years (ranging from 1.29 to 3.53). Female patients and those aged between 40 and 65 years were at the highest risk of Behcet's disease. Only 18.2% of the patients had also suffered from uveitis. The subspecialties of doctors making initial diagnoses and the number of prescribed immunomodulatory agents differed significantly between the patients with and without uveitis (p < 0.001 and <0.05, respectively)., Conclusion: Incidence of Behcet's disease was not high in Taiwan and relatively few of the patients developed uveitis. Patients of working age or who were female were more likely to have Behcet's disease. However, age of onset and clinical severity differed between patients with and without uveitis.
- Published
- 2018
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35. Oral administration of Lactobacillus plantarum CJLP133 and CJLP243 alleviates birch pollen-induced allergic rhinitis in mice.
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Choi SP, Oh HN, Choi CY, Ahn H, Yun HS, Chung YM, Kim B, Lee SJ, and Chun T
- Subjects
- Administration, Oral, Animals, Bronchoalveolar Lavage Fluid immunology, Cytokines genetics, Cytokines immunology, Disease Models, Animal, Female, Humans, Lung drug effects, Lung immunology, Mice, Mice, Inbred BALB C, Rhinitis, Allergic immunology, Betula immunology, Lactobacillus plantarum physiology, Pollen immunology, Probiotics administration & dosage, Rhinitis, Allergic drug therapy
- Abstract
Aims: In this study, we evaluated the therapeutic efficacy of selected probiotics in a mouse model of birch pollen (BP)-induced allergic rhinitis., Methods and Results: Oral administration of Lactobacillus plantarum CJLP133 and CJLP243 ameliorated the symptoms of BP-induced allergic rhinitis by reducing airway hyperresponsiveness, and both the histological scores and the number of infiltrated cells in the nasal cavities and lungs. Compared with those from vehicle-treated mice, bronchoalveolar lavage fluid and draining lymph node samples from CJLP133 and CJLP243-administrated mice showed diminished numbers of immune cells, increased secretion of a Th1-type cytokine (IFN-γ) and decreased production of Th2-type cytokines (IL-4, IL-5 and IL-13). Consistent with these results, levels of IL-4, IL-5, IL-13, serum IgE and BP-specific serum IgG1 were decreased, whereas secretion of IFN-γ and BP-specific serum IgG2a was augmented upon administration of CJLP133 and CJLP243 in mice., Conclusion: Oral administration of L. plantarum CJLP133 and CJLP243 alleviates symptoms of BP-induced allergic rhinitis in mice by recovering Th1/Th2 balance via enhancement of the Th1-type immune response., Significance and Impact of the Study: Lactobacillus plantarum CJLP133 and CJLP243 have therapeutic effects on BP-induced allergic rhinitis in an animal model., (© 2017 The Society for Applied Microbiology.)
- Published
- 2018
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36. Vagus nerve magnetic modulation facilitates dysphagia recovery in patients with stroke involving the brainstem - A proof of concept study.
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Lin WS, Chou CL, Chang MH, Chung YM, Lin FG, and Tsai PY
- Subjects
- Aged, Aged, 80 and over, Australia epidemiology, Deglutition physiology, Deglutition Disorders epidemiology, Deglutition Disorders physiopathology, Double-Blind Method, Female, Humans, Male, Middle Aged, Pilot Projects, Stroke epidemiology, Stroke physiopathology, Brain Stem physiology, Deglutition Disorders therapy, Proof of Concept Study, Recovery of Function physiology, Stroke therapy, Transcranial Magnetic Stimulation methods, Vagus Nerve Stimulation methods
- Abstract
Background & Aims: Stroke involving the brainstem (SBS) causes severe oropharyngeal dysphagia (OD). Research on the therapeutic efficacy of vagus nerve modulation (VNM) by using repetitive transcranial magnetic stimulation (rTMS) in SBS patients with OD has been limited thus far. We aimed to assess the effect of VNM by using rTMS in improving swallowing function after SBS., Method: We conducted a sham-controlled, double-blinded, parallel pilot study in 28 SBS patients with OD randomly allocated to a real rTMS group (n = 13; TMS
real ) or a sham group (n = 15; TMSsham ). For VNM, 5-Hz rTMS was applied to the left mastoid in 10 sessions. We evaluated all patients for swallowing function before and after rTMS conditioning, assessed on the 8-point Penetration-Aspiration Scale (PAS) through videofluoroscopy and the Australian Therapy Outcome Measures-Swallowing scale (AusTOMs). We measured the amplitude and latency of cricopharyngeal motor evoked potentials (CP-MEPs) as the neurophysiological parameters., Results: TMSreal exhibited significant improvement in all swallowing outcomes-neurophysiological, radiological, and functional-compared with TMSsham : We noted higher CP-MEP amplitude (p = 0.004), shorter CP-MEP latency (p = 0.004), a lower PAS score (p = 0.001), and a higher AusTOMs score (p < 0.001) following rTMS in TMSreal . Moreover, the neurophysiological improvements were significantly correlated with the functional outcomes (p < 0.05)., Conclusions: Our results encourage the application of VNM by using rTMS for improving swallowing function after SBS. The immediate therapeutic effects suggest that this novel intervention can be an effective complementary therapy to traditional oropharyngeal rehabilitation., Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02893033., (Copyright © 2017. Published by Elsevier Inc.)- Published
- 2018
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37. Loss of an Androgen-Inactivating and Isoform-Specific HSD17B4 Splice Form Enables Emergence of Castration-Resistant Prostate Cancer.
- Author
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Ko HK, Berk M, Chung YM, Willard B, Bareja R, Rubin M, Sboner A, and Sharifi N
- Subjects
- Humans, Male, Prostatic Neoplasms pathology, Prostatic Neoplasms genetics, Protein Isoforms metabolism, Receptors, Androgen metabolism
- Abstract
Castration-resistant prostate cancer (CRPC) requires tumors to engage metabolic mechanisms that allow sustained testosterone and/or dihydrotestosterone to stimulate progression. 17β-Hydroxysteroid dehydrogenase type 4 (17βHSD4), encoded by HSD17B4, is thought to inactivate testosterone and dihydrotestosterone by converting them to their respective inert 17-keto steroids. Counterintuitively, HSD17B4 expression increases in CRPC and predicts poor prognosis. Here, we show that, of five alternative splice forms, only isoform 2 encodes an enzyme capable of testosterone and dihydrotestosterone inactivation. In contrast with other transcripts, functional expression of isoform 2 is specifically suppressed in development of CRPC in patients. Genetically silencing isoform 2 shifts the metabolic balance toward 17β-OH androgens (testosterone and dihydrotestosterone), stimulating androgen receptor (AR) and CRPC development. Our studies specifically implicate HSD17B4 isoform 2 loss in lethal prostate cancer., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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38. Ursolic acid supplementation decreases markers of skeletal muscle damage during resistance training in resistance-trained men: a pilot study.
- Author
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Bang HS, Seo DY, Chung YM, Kim DH, Lee SJ, Lee SR, Kwak HB, Kim TN, Kim M, Oh KM, Son YJ, Kim S, and Han J
- Abstract
Ursolic acid (UA) supplementation was previously shown to improve skeletal muscle function in resistance-trained men. This study aimed to determine, using the same experimental paradigm, whether UA also has beneficial effects on exercise-induced skeletal muscle damage markers including the levels of cortisol, B-type natriuretic peptide (BNP), myoglobin, creatine kinase (CK), creatine kinase-myocardial band (CK-MB), and lactate dehydrogenase (LDH) in resistance-trained men. Sixteen healthy participants were randomly assigned to resistance training (RT) or RT+UA groups (n=8 per group). Participants were trained according to the RT program (60~80% of 1 repetition, 6 times/week), and the UA group was additionally given UA supplementation (450 mg/day) for 8 weeks. Blood samples were obtained before and after intervention, and cortisol, BNP, myoglobin, CK, CK-MB, and LDH levels were analyzed. Subjects who underwent RT alone showed no significant change in body composition and markers of skeletal muscle damage, whereas RT+UA group showed slightly decreased body weight and body fat percentage and slightly increased lean body mass, but without statistical significance. In addition, UA supplementation significantly decreased the BNP, CK, CK-MB, and LDH levels (p<0.05). In conclusion, UA supplementation alleviates increased skeletal muscle damage markers after RT. This finding provides evidence for a potential new therapy for resistance-trained men., Competing Interests: CONFLICTS OF INTEREST: The authors declare no conflicts of interest.
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- 2017
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39. Direct Metabolic Interrogation of Dihydrotestosterone Biosynthesis from Adrenal Precursors in Primary Prostatectomy Tissues.
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Dai C, Chung YM, Kovac E, Zhu Z, Li J, Magi-Galluzzi C, Stephenson AJ, Klein EA, and Sharifi N
- Subjects
- 3-Oxo-5-alpha-Steroid 4-Dehydrogenase metabolism, Adult, Aged, Animals, Cell Line, Tumor, Chromatography, Liquid, Disease Models, Animal, Heterografts, Humans, Male, Mice, Middle Aged, Neoplasm Grading, Neoplasm Staging, Prostate pathology, Prostatectomy, Prostatic Neoplasms pathology, Prostatic Neoplasms surgery, Steroids metabolism, Substrate Specificity, Tandem Mass Spectrometry, Testosterone metabolism, Dihydrotestosterone metabolism, Metabolic Networks and Pathways, Prostate metabolism, Prostatic Neoplasms metabolism
- Abstract
Purpose: A major mechanism of castration-resistant prostate cancer (CRPC) involves intratumoral biosynthesis of dihydrotestosterone (DHT) from adrenal precursors. We have previously shown that adrenal-derived androstenedione (AD) is the preferred substrate over testosterone (T) for 5α-reductase expressed in metastatic CRPC, bypassing T as an obligate precursor to DHT. However, the metabolic pathway of adrenal-derived DHT biosynthesis has not been rigorously investigated in the setting of primary disease in the prostate. Experimental Design: Seventeen patients with clinically localized prostate cancer were consented for fresh tissues after radical prostatectomy. Prostate tissues were cultured ex vivo in media spiked with an equimolar mixture of AD and T, and stable isotopic tracing was employed to simultaneously follow the enzymatic conversion of both precursor steroids into nascent metabolites, detected by liquid chromatography-tandem mass spectrometry. CRPC cell line models and xenograft tissues were similarly assayed for comparative analysis. A tritium-labeled steroid radiotracing approach was used to validate our findings. Results: Prostatectomy tissues readily 5α-reduced both T and AD. Furthermore, 5α-reduction of AD was the major directionality of metabolic flux to DHT. However, AD and T were comparably metabolized by 5α-reductase in primary prostate tissues, contrasting the preference exhibited by CRPC in which AD was favored over T. 5α-reductase inhibitors effectively blocked the conversion of AD to DHT. Conclusions: Both AD and T are substrates of 5α-reductase in prostatectomy tissues, resulting in two distinctly nonredundant metabolic pathways to DHT. Furthermore, the transition to CRPC may coincide with a metabolic switch toward AD as the favored substrate. Clin Cancer Res; 23(20); 6351-62. ©2017 AACR ., (©2017 American Association for Cancer Research.)
- Published
- 2017
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40. Novel 11-norbetaenone isolated from an entomopathogenic fungus Lecanicillium antillanum.
- Author
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Li CY, Lo IW, Wang SW, Hwang TL, Chung YM, Cheng YB, Tseng SP, Liu YH, Hsu YM, Chen SR, Hu HC, Chang FR, and Wu YC
- Subjects
- Angiogenesis Inhibitors isolation & purification, Crystallography, X-Ray, Diterpenes isolation & purification, Endothelial Progenitor Cells cytology, Endothelial Progenitor Cells drug effects, Humans, Magnetic Resonance Spectroscopy, Models, Molecular, Angiogenesis Inhibitors chemistry, Angiogenesis Inhibitors pharmacology, Diterpenes chemistry, Diterpenes pharmacology, Hypocreales chemistry
- Abstract
A novel nor-betaenone compound, 11-norbetaenone (1), was isolated from the culture broth of an entomopathogenic fungus Lecanicillium antillanum. The structure was determined on the basis of 1D and 2D NMR spectroscopic data. The absolute stereochemistry of 1 was further confirmed by X-ray single crystallography analysis. It is the first secondary metabolite reported from the species Lecanicillium antillanum. And it is also the first time that a betaenone-type compound was isolated from the genus Lecanicillium. Furthermore, 11-norbetaenone (1) displayed significant anti-angiogenic effect by suppressing tube formation., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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41. Gut microbiota-dependent trimethylamine N-oxide in acute coronary syndromes: a prognostic marker for incident cardiovascular events beyond traditional risk factors.
- Author
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Li XS, Obeid S, Klingenberg R, Gencer B, Mach F, Räber L, Windecker S, Rodondi N, Nanchen D, Muller O, Miranda MX, Matter CM, Wu Y, Li L, Wang Z, Alamri HS, Gogonea V, Chung YM, Tang WH, Hazen SL, and Lüscher TF
- Subjects
- Acute Coronary Syndrome drug therapy, Acute Coronary Syndrome metabolism, Biomarkers metabolism, Cardiotonic Agents therapeutic use, Case-Control Studies, Female, Humans, Kaplan-Meier Estimate, Male, Methylamines metabolism, Middle Aged, Myocardial Infarction etiology, Myocardial Infarction mortality, Prognosis, Risk Assessment, Stroke etiology, Stroke mortality, Acute Coronary Syndrome mortality, Gastrointestinal Microbiome physiology
- Abstract
Aims: Systemic levels of trimethylamine N-oxide (TMAO), a pro-atherogenic and pro-thrombotic metabolite produced from gut microbiota metabolism of dietary trimethylamine (TMA)-containing nutrients such as choline or carnitine, predict incident cardiovascular event risks in stable primary and secondary prevention subjects. However, the prognostic value of TMAO in the setting of acute coronary syndromes (ACS) remains unknown., Methods and Results: We investigated the relationship of TMAO levels with incident cardiovascular risks among sequential patients presenting with ACS in two independent cohorts. In the Cleveland Cohort, comprised of sequential subjects (n = 530) presenting to the Emergency Department (ED) with chest pain of suspected cardiac origin, an elevated plasma TMAO level at presentation was independently associated with risk of major adverse cardiac events (MACE, including myocardial infarction, stroke, need for revascularization, or death) over the ensuing 30-day (4th quartile (Q4) adjusted odds ratio (OR) 6.30, 95% confidence interval (CI), 1.89-21.0, P < 0.01) and 6-month (Q4 adjusted OR 5.65, 95%CI, 1.91-16.7; P < 0.01) intervals. TMAO levels were also a significant predictor of the long term (7-year) mortality (Q4 adjusted HR 1.81, 95%CI, 1.04-3.15; P < 0.05). Interestingly, TMAO level at initial presentation predicted risk of incident MACE over the near-term (30 days and 6 months) even among subjects who were initially negative for troponin T (< 0.1 ng/mL) (30 days, Q4 adjusted OR 5.83, 95%CI, 1.79-19.03; P < 0.01). The prognostic value of TMAO was also assessed in an independent multicentre Swiss Cohort of ACS patients (n = 1683) who underwent coronary angiography. Trimethylamine N-oxide again predicted enhanced MACE risk (1-year) (adjusted Q4 hazard ratios: 1.57, 95% CI, 1.03-2.41; P <0.05)., Conclusion: Plasma TMAO levels among patients presenting with chest pain predict both near- and long-term risks of incident cardiovascular events, and may thus provide clinical utility in risk stratification among subjects presenting with suspected ACS., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2017
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42. Long-Term Effects of Middle Ear Tendon Resection on Middle Ear Myoclonic Tinnitus, Hearing, and Hyperacusis.
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Kim DK, Park JM, Han JJ, Chung YM, Kim JM, Park SY, and Park SN
- Abstract
Objective: To evaluate the therapeutic effects of middle ear tendon resection (METR) on middle ear myoclonic tinnitus (MEMT) and to investigate its long-term effects on hearing and hyperacusis., Materials and Methods: Thirty-seven patients with MEMT with a mean age of 33.2 ± 11.8 years were included in this study. METR was performed on all 37 MEMT patients (41 ears) between November 2004 and August 2016. The mean follow-up period was 16.1 months. We examined changes in tinnitus and accompanying stress and depression in patients after surgery, and examined the hearing changes and the occurrence of complications including hyperacusis., Results: After surgery, 34 (91.9%) patients exhibited complete resolution of MEMT during their follow-up period, and 3 patients showed a partial response. The mean Visual Analog Scale (VAS) scores for tinnitus severity, the Tinnitus Handicap Inventory (THI), and stress index decreased significantly after surgery (p < 0.05, paired t test). No patient developed hearing loss or hyperacusis following surgery. Preexisting hyperacusis even improved in most of the patients with intractable MEMT after surgery. Recurrence of the symptom occurred in only 1 patient, who underwent revision surgery with improvement. We observed 1 case of postoperative delayed facial palsy with complete recovery in 2 weeks., Conclusions: METR seems to be an effective and safe treatment option for intractable MEMT, considering its high control rate of tinnitus and no long-term harmful effects on hearing and hyperacusis., (© 2018 S. Karger AG, Basel.)
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- 2017
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43. One size does not fit all: Individual differences in cardiac autonomic and subjective responses to brief relaxation activities.
- Author
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Cvejic E, Lynar EC, Chung YM, and Vollmer-Conna U
- Subjects
- Acoustic Stimulation methods, Adolescent, Adult, Electrocardiography methods, Female, Humans, Male, Random Allocation, Young Adult, Autonomic Nervous System physiology, Heart Rate physiology, Individuality, Relaxation physiology, Respiratory Rate physiology
- Published
- 2016
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44. Pharmacological activation of FOXO3 suppresses triple-negative breast cancer in vitro and in vivo.
- Author
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Park SH, Chung YM, Ma J, Yang Q, Berek JS, and Hu MC
- Subjects
- Animals, Apoptosis, Bepridil pharmacology, Breast Neoplasms metabolism, Cell Nucleus metabolism, Dopamine metabolism, Female, Gene Expression Regulation, Neoplastic, Humans, Kruppel-Like Transcription Factors metabolism, MCF-7 Cells, Mice, Mice, Nude, Neoplastic Stem Cells, Phosphorylation, Proto-Oncogene Proteins c-myc metabolism, RNA, Small Interfering metabolism, Receptors, Dopamine D2 metabolism, Trifluoperazine pharmacology, Triple Negative Breast Neoplasms metabolism, Breast Neoplasms drug therapy, Forkhead Box Protein O3 metabolism, Gene Silencing, Triple Negative Breast Neoplasms drug therapy
- Abstract
Triple-negative breast cancer (TNBC) is the most lethal form of breast cancer. Lacking effective therapeutic options hinders treatment of TNBC. Here, we show that bepridil (BPD) and trifluoperazine (TFP), which are FDA-approved drugs for treatment of schizophrenia and angina respectively, inhibit Akt-pS473 phosphorylation and promote FOXO3 nuclear localization and activation in TNBC cells. BPD and TFP inhibit survival and proliferation in TNBC cells and suppress the growth of TNBC tumors, whereas silencing FOXO3 reduces the BPD- and TFP-mediated suppression of survival in TNBC cells. While BPD and TFP decrease the expression of oncogenic c-Myc, KLF5, and dopamine receptor DRD2 in TNBC cells, silencing FOXO3 diminishes BPD- and TFP-mediated repression of the expression of these proteins in TNBC cells. Since c-Myc, KLF5, and DRD2 have been suggested to increase cancer stem cell-like populations in various tumors, reducing these proteins in response to BPD and TFP suggests a novel FOXO3-dependent mechanism underlying BPD- and TFP-induced apoptosis in TNBC cells., Competing Interests: All authors have no conflicts of interest in this study.
- Published
- 2016
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45. Microfluidic preparation of a highly active and stable catalyst by high performance of encapsulation of polyvinylpyrrolidone (PVP)-Pt nanoparticles in microcapsules.
- Author
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Nam JO, Kim J, Jin SH, Chung YM, and Lee CS
- Abstract
The encapsulation of active metals in microcapsules would be highly advantageous in maintaining or improving the reaction performance of an array of widely used chemical reactions. However, conventional methods suffer from low uniformity, complicated fabrication steps, sintering, leaching, decline of catalytic activity, and/or poor reusability. Here, we report an efficient microfluidic approach to encapsulate Pt nanoparticle stabilized by polyvinylpyrrolidone (PVP) in photocurable double-emulsion droplets with semipermeable thin shells. The encapsulated catalysts are prepared by the in situ photopolymerization of a double emulsion. The rapid and exquisite microfluidics-based fabrication process successfully generates monodisperse microcapsules without loss of the PVP-Pt nanoparticles, which is the first demonstration of the microfluidic encapsulation of active metal with promising catalytic activity. Specifically, compared to quasi-homogeneous catalysis of PVP-Pt nanoparticles for 4-nitrophenol hydrogenation, the encapsulated PVP-Pt nanoparticles demonstrate excellent catalytic activity, a leaching-proof nature, and high reusability under the same reaction conditions. We envision that the approach described here may be an example of elegant catalyst design to efficiently overcome difficult problems in active-metal encapsulation and to dramatically enhance catalytic activity by taking advantage of the unique aspects of microfluidic methods., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2016
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46. Effects of Low-Dose Bisphenol A on DNA Damage and Proliferation of Breast Cells: The Role of c-Myc.
- Author
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Pfeifer D, Chung YM, and Hu MC
- Subjects
- Cell Line, Cell Line, Tumor, Estrogen Receptor alpha metabolism, Female, Gene Silencing, Humans, Mammary Glands, Human cytology, Mammary Glands, Human metabolism, Proto-Oncogene Proteins c-myc genetics, Proto-Oncogene Proteins c-myc metabolism, RNA, Small Interfering genetics, Up-Regulation, Benzhydryl Compounds toxicity, Cell Proliferation drug effects, DNA Damage drug effects, Environmental Pollutants toxicity, Genes, myc, Mammary Glands, Human drug effects, Phenols toxicity
- Abstract
Background: Humans are exposed to low-dose bisphenol A (BPA) through plastic consumer products and dental sealants containing BPA. Although a number of studies have investigated the mammary gland effects after high-dose BPA exposure, the study findings differ. Furthermore, there has been a lack of mechanistic studies., Objective: The objective of this study was to investigate the effect and the mechanism of low-dose BPA in mammary gland cells., Methods: We evaluated DNA damage following BPA exposure using the comet assay and immunofluorescence staining, and used cell counting and three-dimensional cultures to evaluate effects on proliferation. We examined the expressions of markers of DNA damage and cell-cycle regulators by immunoblotting and performed siRNA-mediated gene silencing to determine the role of c-Myc in regulating BPA's effects., Results: Low-dose BPA significantly promoted DNA damage, up-regulated c-Myc and other cell-cycle regulatory proteins, and induced proliferation in parallel in estrogen receptor-α (ERα)-negative mammary cells. Silencing c-Myc diminished these BPA-induced cellular events, suggesting that c-Myc is essential for regulating effects of BPA on DNA damage and proliferation in mammary cells., Conclusions: Low-dose BPA exerted c-Myc-dependent genotoxic and mitogenic effects on ERα-negative mammary cells. These findings provide significant evidence of adverse effects of low-dose BPA on mammary cells.
- Published
- 2015
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47. High MicroRNA-370 Expression Correlates with Tumor Progression and Poor Prognosis in Breast Cancer.
- Author
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Sim J, Ahn H, Abdul R, Kim H, Yi KJ, Chung YM, Chung MS, Paik SS, Song YS, and Jang K
- Abstract
Purpose: Deregulation of microRNA-370 (miR-370) has been reported in various cancers, in which it can act as either an oncogene or a tumor suppressor gene. However, the clinicopathologic significance of miR-370 expression in breast cancer has not been studied., Methods: The expression of miR-370 was determined with quantitative real-time polymerase chain reaction in 60 formalin-fixed, paraffin-embedded primary breast cancer tissues. Additionally, the protein expression levels of previously known targets of miR-370, such as FOXM1, FOXO1, and FOXO3a, were detected using immunohistochemistry. Finally, we analyzed its correlation with target protein expression, clinicopathologic features, and clinical outcome., Results: High levels of miR-370 expression correlated with lymph node metastasis (p=0.009), advanced stage (p=0.002), and frequent perineural invasion (p=0.042). Moreover, patients with high miR-370 expression had poor disease-free survival compared with the low-expression group. However, no correlation was observed between miR-370 and its target protein expression., Conclusion: Our results indicate that upregulation of miR-370 in breast cancer is correlated with breast cancer progression and that it might be a potential biomarker for predicting clinical outcomes.
- Published
- 2015
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48. Alkaloids from Pandanus amaryllifolius: Isolation and Their Plausible Biosynthetic Formation.
- Author
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Tsai YC, Yu ML, El-Shazly M, Beerhues L, Cheng YB, Chen LC, Hwang TL, Chen HF, Chung YM, Hou MF, Wu YC, and Chang FR
- Subjects
- Alkaloids chemistry, Antioxidants chemistry, Antioxidants isolation & purification, Antioxidants metabolism, Furans chemistry, Furans isolation & purification, Furans metabolism, Lactones chemistry, Lactones isolation & purification, Lactones metabolism, Molecular Structure, Nuclear Magnetic Resonance, Biomolecular, Plant Components, Aerial chemistry, Plant Leaves chemistry, Pyrrolidines chemistry, Pyrrolidines isolation & purification, Pyrrolidines metabolism, Stereoisomerism, Taiwan, Alkaloids isolation & purification, Alkaloids metabolism, Pandanaceae chemistry
- Abstract
Pandanus amaryllifolius Roxb. (Pandanaceae) is used as a flavor and in folk medicine in Southeast Asia. The ethanolic crude extract of the aerial parts of P. amaryllifolius exhibited antioxidant, antibiofilm, and anti-inflammatory activities in previous studies. In the current investigation, the purification of the ethanolic extract yielded nine new compounds, including N-acetylnorpandamarilactonines A (1) and B (2); pandalizines A (3) and B (4); pandanmenyamine (5); pandamarilactones 2 (6) and 3 (7), and 5(E)-pandamarilactonine-32 (8); and pandalactonine (9). The isolated alkaloids, with either a γ-alkylidene-α,β-unsaturated-γ-lactone or γ-alkylidene-α,β-unsaturated-γ-lactam system, can be classified into five skeletons including norpandamarilactonine, indolizinone, pandanamine, pandamarilactone, and pandamarilactonine. A plausible biosynthetic route toward 1-5, 7, and 9 is proposed.
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- 2015
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49. The Novel Ribonucleotide Reductase Inhibitor COH29 Inhibits DNA Repair In Vitro.
- Author
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Chen MC, Zhou B, Zhang K, Yuan YC, Un F, Hu S, Chou CM, Chen CH, Wu J, Wang Y, Liu X, Smith DL, Li H, Liu Z, Warden CD, Su L, Malkas LH, Chung YM, Hu MC, and Yen Y
- Subjects
- Animals, Antimetabolites, Antineoplastic therapeutic use, BRCA1 Protein genetics, Benzamides therapeutic use, Breast Neoplasms drug therapy, Breast Neoplasms pathology, Cell Line, Tumor, DNA Breaks, Double-Stranded drug effects, DNA End-Joining Repair drug effects, Female, Heterografts, Humans, Mice, Inbred NOD, Mutagenicity Tests, Neoplasm Transplantation, Thiazoles therapeutic use, Zebrafish, Antimetabolites, Antineoplastic pharmacology, Benzamides pharmacology, DNA Repair drug effects, Ribonucleotide Reductases antagonists & inhibitors, Thiazoles pharmacology
- Abstract
COH29 [N-(4-(3,4-dihydroxyphenyl)-5-phenylthiazol-2-yl)-3,4-dihydroxybenzamide], a novel antimetabolite drug developed at City of Hope Cancer Center, has anticancer activity that stems primarily from the inhibition of human ribonucleotide reductase (RNR). This key enzyme in deoxyribonucleotide biosynthesis is the target of established clinical agents such as hydroxyurea and gemcitabine because of its critical role in DNA replication and repair. Herein we report that BRCA-1-defective human breast cancer cells are more sensitive than wild-type BRCA-1 counterparts to COH29 in vitro and in vivo. Microarray gene expression profiling showed that COH29 reduces the expression of DNA repair pathway genes, suggesting that COH29 interferes with these pathways. It is well established that BRCA1 plays a role in DNA damage repair, especially homologous recombination (HR) repair, to maintain genome integrity. In BRCA1-defective HCC1937 breast cancer cells, COH29 induced more double-strand breaks (DSBs) and DNA-damage response than in HCC1937 + BRCA1 cells. By EJ5- and DR-green fluorescent protein (GFP) reporter assay, we found that COH29 could inhibit nonhomologous end joining (NHEJ) efficiency and that no HR activity was detected in HCC1937 cells, suggesting that repression of the NHEJ repair pathway may be involved in COH29-induced DSBs in BRCA1-deficient HCC1937 cells. Furthermore, we observed an accumulation of nuclear Rad51 foci in COH29-treated HCC1937 + BRCA1 cells, suggesting that BRCA1 plays a crucial role in repairing and recovering drug-induced DNA damage by recruiting Rad51 to damage sites. In summary, we describe here additional biologic effects of the RNR inhibitor COH29 that potentially strengthen its use as an anticancer agent., (Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.)
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- 2015
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50. Metformin enhances the anti-adipogenic effects of atorvastatin via modulation of STAT3 and TGF-β/Smad3 signaling.
- Author
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Kim BH, Han S, Lee H, Park CH, Chung YM, Shin K, Lee HG, and Ye SK
- Subjects
- 3T3-L1 Cells, Adipocytes cytology, Adipocytes drug effects, Adipogenesis, Animals, Atorvastatin, Cell Differentiation, Cell Survival, Cyclin D1 metabolism, Homeostasis, Kruppel-Like Transcription Factors metabolism, Mice, Signal Transduction drug effects, Smad7 Protein metabolism, Tumor Suppressor Protein p53 metabolism, Heptanoic Acids pharmacology, Hypoglycemic Agents pharmacology, Metformin pharmacology, Pyrroles pharmacology, STAT3 Transcription Factor metabolism, Smad3 Protein metabolism, Transforming Growth Factor beta metabolism
- Abstract
Adipocyte accumulation is associated with the development of obesity and obesity-related diseases. Interactions of master transcription factors and signaling cascades are required for adipogenesis. Regulation of excessive adipogenic processes may be an attractive therapeutic for treatment of obesity and obesity-related diseases. In this study, we found that atorvastatin exerts an anti-adipogenic activity in 3T3-L1 pre-adipocytes, and that this activity is elevated in combination with metformin. Expression of the adipogenic master regulators PPARγ and C/EBPα, and their target gene aP2, was suppressed by atorvastatin. Furthermore, atorvastatin treatment resulted in increased activation of the key master regulator of cellular energy homeostasis, AMPK. These biological activities of atorvastatin were elevated in combination with metformin. These anti-adipogenic activities were associated with regulation of the STAT3 and TGF-β signaling cascades, resulting in the regulation of the expression of STAT3 target genes, such as KLF5, p53, and cyclin D1, and TGF-β signaling inhibitory genes, such as SMAD7. Our results suggest that combination therapy with atorvastatin and metformin may have therapeutic potential for the treatment of obesity and obesity-related diseases caused by excessive adipogenesis., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
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