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2.
J Clin Oncol ; 41(33): 5151-5162, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37607324

RESUMO

PURPOSE: To determine the genetic predisposition underlying pancreatic acinar cell carcinoma (PACC) and characterize its genomic features. METHODS: Both somatic and germline analyses were performed using an Food and Drug Administration-authorized matched tumor/normal sequencing assay on a clinical cohort of 28,780 patients with cancer, 49 of whom were diagnosed with PACC. For a subset of PACCs, whole-genome sequencing (WGS; n = 12) and RNA sequencing (n = 6) were performed. RESULTS: Eighteen of 49 (36.7%) PACCs harbored germline pathogenic variants in homologous recombination (HR) and DNA damage response (DDR) genes, including BRCA1 (n = 1), BRCA2 (n = 12), PALB2 (n = 2), ATM (n = 2), and CHEK2 (n = 1). Thirty-one PACCs displayed pure, and 18 PACCs harbored mixed acinar cell histology. Fifteen of 31 (48%) pure PACCs harbored a germline pathogenic variant affecting HR-/DDR-related genes. BRCA2 germline pathogenic variants (11 of 31, 35%) were significantly more frequent in pure PACCs than in pancreatic adenocarcinoma (86 of 2,739, 3.1%; P < .001), high-grade serous ovarian carcinoma (67 of 1,318, 5.1%; P < .001), prostate cancer (116 of 3,401, 3.4%; P < .001), and breast cancer (79 of 3,196, 2.5%; P < .001). Genomic features of HR deficiency (HRD) were detected in 7 of 12 PACCs undergoing WGS, including 100% (n = 6) of PACCs with germline HR-related pathogenic mutations and 1 of 6 PACCs lacking known pathogenic alterations in HR-related genes. Exploratory analyses revealed that in PACCs, the repertoire of somatic driver genetic alterations and the load of neoantigens with high binding affinity varied according to the presence of germline pathogenic alterations affecting HR-/DDR-related genes and/or HRD. CONCLUSION: In a large pan-cancer cohort, PACC was identified as the cancer type with the highest prevalence of both BRCA2 germline pathogenic variants and genomic features of HRD, suggesting that PACC should be considered as part of the spectrum of BRCA-related malignancies.


Assuntos
Carcinoma de Células Acinares , Neoplasias Pancreáticas , Masculino , Humanos , Carcinoma de Células Acinares/genética , Neoplasias Pancreáticas/genética , Proteína BRCA2/genética , Proteína BRCA1/genética , Mutação em Linhagem Germinativa , Predisposição Genética para Doença , Recombinação Homóloga , Genômica , Neoplasias Pancreáticas
3.
Mol Diagn Ther ; 26(6): 645-653, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36178671

RESUMO

BACKGROUND AND OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) is characterized by the occurrence of pathogenic variants in BRCA1/2 in 5-6% of patients. Biallelic loss of BRCA1/2 enriches for response to platinum agents and poly (ADP-ribose) polymerase 1 inhibitors. There is a dearth of evidence on the mechanism of inactivation of the wild-type BRCA1 allele in PDAC tumors with a germline BRCA1 (gBRCA1) pathogenic or likely pathogenic variant (P/LPV). Herein, we examine promotor hypermethylation as a "second hit" mechanism in patients with gBRCA1-PDAC. METHODS: We evaluated patients with PDAC who underwent Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT) somatic and germline testing from an institutional database. DNA isolated from tumor tissue and matched normal peripheral blood were sequenced by MSK-IMPACT. In patients with gBRCA1-PDAC, we examined the somatic BRCA1 mutation status and promotor methylation status of the tumor BRCA1 allele via a methylation array analysis. In patients with sufficient remaining DNA, a second methylation analysis by pyrosequencing was performed. RESULTS: Of 1012 patients with PDAC, 19 (1.9%) were identified to harbor a gBRCA1 P/LPV. Fifteen patients underwent a methylation array and the mean percentage of BRCA1 promotor methylation was 3.62%. In seven patients in whom sufficient DNA was available, subsequent pyrosequencing confirmed an unmethylated BRCA1 promotor. Loss of heterozygosity was detected in 12 of 19 (63%, 95% confidence interval 38-84) patients, demonstrating loss of heterozygosity is the major molecular mechanism of BRCA1 inactivation in PDAC. Two (10.5%) cases had a somatic BRCA1 mutation. CONCLUSIONS: In patients with gBRCA1-P/LPV-PDAC, loss of heterozygosity is the main inactivating mechanism of the wild-type BRCA1 allele in the tumor, and methylation of the BRCA1 promoter is a distinctly uncommon occurrence.


Assuntos
Proteína BRCA1 , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Proteína BRCA1/genética , Carcinoma Ductal Pancreático/genética , Neoplasias Pancreáticas/genética , Inibidores de Poli(ADP-Ribose) Polimerases , Mutação em Linhagem Germinativa , Metilação de DNA , Regiões Promotoras Genéticas , Neoplasias Pancreáticas
4.
J Mol Diagn ; 22(3): 368-375, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31881335

RESUMO

Clinical testing for MLH1 promoter hypermethylation status is important in the workup of patients with MLH1-deficient colorectal and uterine carcinomas when evaluating patients for Lynch syndrome. Current assays use single gene-based methods to assess promoter hypermethylation. Herein, we describe the development and report the performance of a clinical assay for MLH1 promoter hypermethylation using the Infinium methylationEPIC (850k) bead-array platform. Using four cytosine-guanine dinucleotide (CpG) sites within the MLH1 gene promoter, a qualitative MLH1 promoter hypermethylation assay was developed and validated using 63 gastrointestinal and uterine carcinoma samples of known hypermethylation status based on a pyrosequencing reference test. The array-based method achieves clinically robust and reproducible results at an analytical sensitivity level of 8%. Of importance, the 850k array contains probes targeting >850,000 additional CpG sites across the genome, covering sites in most known genes as well as important enhancer regions provided by the Encyclopedia of DNA Elements and Functional Annotation of The Mammalian Genome projects. Thus, the testing modality presented may also be applied to determine the methylation status of other clinically relevant genes or regulatory regions, potentially providing a single laboratory testing workflow for all clinical methylation assays. Furthermore, the concomitant acquisition of genome-wide methylation information provides a workflow that seamlessly enables wider translational epigenetic research.


Assuntos
Metilação de DNA , Epigenômica , Estudo de Associação Genômica Ampla , Sequenciamento de Nucleotídeos em Larga Escala , Proteína 1 Homóloga a MutL/genética , Regiões Promotoras Genéticas , Ilhas de CpG , Epigenômica/métodos , Feminino , Estudo de Associação Genômica Ampla/métodos , Estudo de Associação Genômica Ampla/normas , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
5.
Cancer Res ; 79(6): 1047-1053, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30643016

RESUMO

Kinase fusions are rare and poorly characterized in colorectal carcinoma, yet they present unique opportunities for targeted therapy. In this study, we characterized kinase fusions from patients with advanced colorectal carcinoma who had MSK-IMPACT testing of their tumors between January 2014 and June 2018. Patients were analyzed for the presence of fusions, microsatellite instability (MSI), and RAS/BRAF mutations. Mismatch repair (MMR), IHC, and promoter hypermethylation status of MLH1 (MLH1ph) in microsatellite instability-high (MSI-H) colorectal carcinoma with fusions were investigated. Fusion transcripts were confirmed using a targeted RNA-seq panel assay. Of 2,314 colorectal carcinomas with MSK-IMPACT testing, 21 harbored kinase fusions. Overall 57% (12/21) of colorectal carcinoma fusions were MSI-H/MMR-D. Loss of MLH1 and MLH1ph was confirmed in all 12 and all 10 cases with available material, respectively. Fusions were present in 5% of MSI-H/MMR-D colorectal carcinoma compared with 0.4% of MSS/MMR-P colorectal carcinoma (P < 0.001) and 15% of MSI-H/MMR-D colorectal carcinoma with wild-type RAS/BRAF. Of 24 total MLH1-deficient colorectal carcinomas with MLH1ph and wild-type RAS/BRAF, 10 (42%) harbored kinase fusions. Kinase fusions in MSI-H colorectal carcinoma were associated with sporadic MLH1ph rather than with Lynch syndrome, and these patients may be eligible for kinase inhibitors, particularly following resistance or toxicity in response to immunotherapy. These findings identify a molecular subset of colorectal carcinoma with kinase fusions that may be responsive to kinase inhibitors.Significance: A high frequency of targetable kinase fusions in BRAF/RAS wild-type, MSI-H colorectal carcinoma offers a rationale for routine screening to identify patients with colorectal carcinoma with kinase fusions that may be responsive to kinase inhibitors.See related commentary by Valeri, p. 1041.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias Colorretais/genética , Metilação de DNA , Proteína 1 Homóloga a MutL/genética , Proteínas de Fusão Oncogênica/análise , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Neoplasias Colorretais/patologia , Feminino , Seguimentos , Humanos , Masculino , Instabilidade de Microssatélites , Pessoa de Meia-Idade , Mutação , Metástase Neoplásica , Proteínas de Fusão Oncogênica/genética , Prognóstico , Regiões Promotoras Genéticas
6.
BMC Med Genomics ; 10(1): 33, 2017 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-28526081

RESUMO

BACKGROUND: The growing number of Next Generation Sequencing (NGS) tests is transforming the routine clinical diagnosis of hereditary cancers. Identifying whether a cancer is the result of an underlying disease-causing mutation in a cancer predisposition gene is not only diagnostic for a cancer predisposition syndrome, but also has significant clinical implications in the clinical management of patients and their families. METHODS: Here, we evaluated the performance of MSK-IMPACT (Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets) in detecting genetic alterations in 76 genes implicated in cancer predisposition syndromes. Output from hybridization-based capture was sequenced on an Illumina HiSeq 2500. A custom analysis pipeline was used to detect single nucleotide variants (SNVs), small insertions/deletions (indels) and copy number variants (CNVs). RESULTS: MSK-IMPACT detected all germline variants in a set of 233 unique patient DNA samples, previously confirmed by previous single gene testing. Reproducibility of variant calls was demonstrated using inter- and intra- run replicates. Moreover, in 16 samples, we identified additional pathogenic mutations other than those previously identified through a traditional gene-by-gene approach, including founder mutations in BRCA1, BRCA2, CHEK2 and APC, and truncating mutations in TP53, TSC2, ATM and VHL. CONCLUSIONS: This study highlights the importance of the NGS-based gene panel testing approach in comprehensively identifying germline variants contributing to cancer predisposition and simultaneous detection of somatic and germline alterations.


Assuntos
Análise Mutacional de DNA/métodos , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Proteínas de Neoplasias/genética , Neoplasias/metabolismo , Proteína da Polipose Adenomatosa do Colo/genética , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteína BRCA1/genética , Proteína BRCA2/genética , Biomarcadores Tumorais/genética , Quinase do Ponto de Checagem 2/genética , Variações do Número de Cópias de DNA , Humanos , Neoplasias/genética , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Proteína 2 do Complexo Esclerose Tuberosa , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor/genética , Proteína Supressora de Tumor Von Hippel-Lindau/genética
7.
JCO Precis Oncol ; 20172017.
Artigo em Inglês | MEDLINE | ID: mdl-30211344

RESUMO

PURPOSE: Microsatellite instability (MSI)/mismatch repair (MMR) status is increasingly important in the management of patients with cancer to predict response to immune checkpoint inhibitors. We determined MSI status from large-panel clinical targeted next-generation sequencing (NGS) data across various solid cancer types. METHODS: The MSI statuses of 12,288 advanced solid cancers consecutively sequenced with Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets clinical NGS assay were inferred by using MSIsensor, a program that reports the percentage of unstable microsatellites as a score. Cutoff score determination and sensitivity/specificity were based on MSI polymerase chain reaction (PCR) and MMR immunohistochemistry. RESULTS: By using an MSIsensor score ≥ 10 to define MSI high (MSI-H), 83 (8%) of 996 colorectal cancers (CRCs) and 42 (16%) of 260 uterine endometrioid cancers (UECs) were MSI-H. Validation against MSI PCR and/or MMR immunohistochemistry performed for 138 (24 MSI-H, 114 microsatellite stable [MSS]) CRCs, and 40 (15 MSI-H, 25 MSS) UECs showed a concordance of 99.4%. MSIsensor also identified 68 MSI-H/MMR-deficient (MMR-D) non-CRC/UECs. Of 9,591 non-CRC/UEC tumors with MSS MSIsensor status, 456 (4.8%) had slightly elevated scores(≥3 and <10) of which 96.6% with available material were confirmed to be MSS by MSI PCR. MSI-H was also detected and confirmed in three non-CRC/UECs with low exonic mutation burden (< 20). MSIsensor correctly scored all 15 polymerase ε ultra-mutated cancers as negative for MSI. CONCLUSION: MSI status can be reliably inferred by MSIsensor from large-panel targeted NGS data. Concurrent MSI testing by NGS is resource efficient, is potentially more sensitive for MMR-D than MSI PCR, and allows identification of MSI-H across various cancers not typically screened, as highlighted by the finding that 35% (68 of 193) of all MSI-H tumors were non-CRC/ UEC.

8.
J Ovarian Res ; 7: 21, 2014 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-24524197

RESUMO

BACKGROUND: Polycystic ovary syndrome (PCOS) is characterized by ovarian enlargement, hyperplastic theca compartment and increased androgen production due to, at least in part, excessive expression of several key genes involved in steroidogenesis. Previously, our group has demonstrated that simvastatin, competitive inhibitor of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA reductase), a rate-limiting step of the mevalonate pathway, reduces rat-theca interstitial cell steroidogenesis by inhibiting Cyp17a1 gene expression, the key enzyme of the androgen biosynthesis pathway. Recently, we demonstrated that resveratrol, a bioflavonoid abundant in red grapes, decreases rat theca-interstitial cell steroidogenesis and this suppressive effect is mediated through mechanisms independent of the mevalonate pathway. The present study evaluated the effect of combining simvastatin and resveratrol treatments on rat theca-interstitial cell steroidogenesis. METHODS: Rat theca-interstitial cells isolated from 30 day-old female rats were cultured for up to 48 h with or without simvastatin (1 µM) and/or resveratrol (3-10 µM). Steroidogenic enzymes gene expression was evaluated by quantitative real time PCR and steroid levels were measured by liquid chromatography-mass spectrometry. Comparisons between groups were performed using ANOVA and Tukey test. RESULTS: Resveratrol potentiated inhibitory effects of simvastatin on androstenedione and androsterone production in theca-interstitial cells. This suppressive effect correlated with profound inhibition in Cyp17a1 mRNA expression in the presence of a combination of resveratrol and simvastatin. CONCLUSIONS: The present findings indicate that resveratrol potentiates the simvastatin-induced inhibitory effect on theca-interstitial cell androgen production, raising the possibility of development of novel treatments of PCOS.


Assuntos
Androstenodiona/biossíntese , Androsterona/biossíntese , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Sinvastatina/farmacologia , Estilbenos/farmacologia , Células Tecais/efeitos dos fármacos , Animais , Células Cultivadas , Relação Dose-Resposta a Droga , Regulação para Baixo , Sinergismo Farmacológico , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Resveratrol , Esteroide 17-alfa-Hidroxilase/genética , Esteroide 17-alfa-Hidroxilase/metabolismo , Células Tecais/enzimologia , Fatores de Tempo
9.
Fertil Steril ; 99(3): 889-96, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23200686

RESUMO

OBJECTIVE: To evaluate the effects of letrozole on ovarian size and steroidogenesis in vivo, as well as on proliferation and steroidogenesis of theca-interstitial cells alone and in coculture with granulosa cells using an in vitro model. DESIGN: In vivo and in vitro studies. SETTING: Research laboratory. ANIMAL(S): Immature Sprague-Dawley female rats. INTERVENTION(S): In vivo effects of letrozole were studied in intact rats receiving either letrozole (90-day continuous-release SC pellets, 400 µg/d) or placebo pellets (control group). In in vitro experiments, theca cells were cultured alone or in coculture with granulosa cells in the absence or presence of letrozole. MAIN OUTCOME MEASURE(S): Deoxyribonucleic acid synthesis was determined by thymidine incorporation assay; steroidogenesis by mass spectrometry; and steroidogenic enzyme messenger RNA (mRNA) expression by polymerase chain reaction. RESULT(S): In vivo, letrozole induced an increase in ovarian size compared with the control group and also induced a profound increase of androgen, LH levels, and Cyp17a1 mRNA expression. Conversely, a decrease in Star, Cyp11a1, and Hsd3b1 transcripts was observed in letrozole-exposed rats. In vitro, letrozole did not alter either theca cell proliferation or Cyp17a1 mRNA expression. Similarly, letrozole did not affect Cyp17a1 transcripts in granulosa-theca cocultures. CONCLUSION(S): These findings suggest that letrozole exerts potent, but indirect, effect on growth of rat ovary and dramatically increases androgen levels and Cyp17a1 mRNA expression, the key enzyme regulating the androgen biosynthesis pathway. The present findings reveal novel mechanisms of action of letrozole in the rat ovary.


Assuntos
Nitrilas/farmacologia , Ovário/efeitos dos fármacos , Ovário/crescimento & desenvolvimento , Esteroide 17-alfa-Hidroxilase/genética , Triazóis/farmacologia , Animais , Inibidores da Aromatase/farmacologia , Proteínas de Bactérias , Peso Corporal/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Ciclo Estral/efeitos dos fármacos , Feminino , Expressão Gênica/efeitos dos fármacos , Células da Granulosa/citologia , Células da Granulosa/efeitos dos fármacos , Células da Granulosa/fisiologia , Hormônios/metabolismo , Letrozol , Tamanho do Órgão/efeitos dos fármacos , Ovário/fisiologia , RNA Mensageiro/metabolismo , Ratos , Proteínas Repressoras , Células Tecais/citologia , Células Tecais/efeitos dos fármacos , Células Tecais/fisiologia
10.
Fertil Steril ; 98(6): 1563-73, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22959450

RESUMO

OBJECTIVE: To evaluate the effects of resveratrol on growth and function of granulosa cells. Previously, we demonstrated that resveratrol exerts profound proapoptotic effects on theca-interstitial cells. DESIGN: In vitro study. SETTING: Research laboratory. ANIMAL(S): Immature Sprague-Dawley female rats. INTERVENTION(S): Granulosa cells were cultured in the absence or presence of resveratrol. MAIN OUTCOME MEASURE(S): DNA synthesis was determined by thymidine incorporation assay, apoptosis by activity of caspases 3/7, cell morphology by immunocytochemistry, steroidogenesis by mass spectrometry, antimüllerian hormone (AMH), and vascular endothelial growth factor (VEGF) expression by polymerase chain reaction and Western blot. RESULT(S): Resveratrol induced a biphasic effect on DNA synthesis, whereby a lower concentration stimulated thymidine incorporation and higher concentrations inhibited it. Additionally, resveratrol slightly increased the cell number and modestly decreased the activity of caspases 3/7 with no effect on cell morphology or progesterone production. However, resveratrol decreased aromatization and VEGF expression, whereas AMH expression remained unaltered. CONCLUSION(S): Resveratrol, by exerting cytostatic but not cytotoxic effects, together with antiangiogenic actions mediated by decreased VEGF in granulosa cells, may alter the ratio of theca-to-granulosa cells and decrease vascular permeability, and therefore may be of potential therapeutic use in conditions associated with highly vascularized theca-interstitial hyperplasia and abnormal angiogenesis, such as those seen in women with polycystic ovary syndrome.


Assuntos
Células da Granulosa/citologia , Células da Granulosa/fisiologia , Estilbenos/administração & dosagem , Inibidores da Angiogênese/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Células da Granulosa/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Resveratrol
11.
Endocrinology ; 153(8): 4019-29, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22719052

RESUMO

Polycystic ovary syndrome is characterized by theca-interstitial hyperplasia and increased expression of steroidogenic genes, leading to excessive androgen production. Resveratrol, a natural polyphenol, promotes apoptosis and reduces rat theca-interstitial cell growth, in part by inhibiting the mevalonate pathway and decreasing the availability of substrates of isoprenylation [farnesyl-pyrophosphate (FPP) and geranylgeranyl-pyrophosphate (GGPP)]. This study evaluated the effect of resveratrol on rat theca-interstitial cell steroidogenesis. Because resveratrol may activate sirtuins, this study also investigated whether steroidogenesis was affected by sirtuin inhibitors (nicotinamide, sirtinol). Theca-interstitial cells were cultured with or without resveratrol (1-10 µm), GGPP (30 µm), FPP (30 µm), nicotinamide (1 mm), and/or sirtinol (10 µm). Resveratrol did not affect progesterone levels but reduced androgen production in a concentration-dependent fashion (androstenedione by up to 78% and androsterone by up to 76%). This inhibitory effect correlated with a decrease in mRNA expression of genes regulating androgen production, especially Cyp17a1 (by up to 73%). GGPP and FPP had no effect on androgen levels and Cyp17a1 mRNA levels and did not alter the effects induced by resveratrol. Similarly, sirtuin inhibitors did not reverse resveratrol-induced inhibition of steroidogenesis. However, resveratrol decreased activity of serine-threonine kinase/protein kinase B pathway, a cell-signaling pathway involved in ovarian steroidogenesis. The present findings indicate that resveratrol reduces androgen production primarily by inhibiting Cyp17a1 mRNA expression, and this inhibition may be mediated, in part, by blocking the activity of the serine-threonine kinase/protein kinase B pathway. These findings may be of clinical relevance to conditions associated with excessive production of androgens by theca cells, such as polycystic ovary syndrome.


Assuntos
Ovário/citologia , Estilbenos/farmacologia , Células Tecais/efeitos dos fármacos , Células Tecais/metabolismo , Animais , Western Blotting , Células Cultivadas , Feminino , Espectrometria de Massas , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Resveratrol , Esteroides/metabolismo
12.
Biol Reprod ; 86(1): 1-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21918126

RESUMO

Polycystic ovary syndrome (PCOS) is characterized by ovarian enlargement, theca-interstitial hyperplasia, and increased androgen production by theca cells. Previously, our group has demonstrated that statins (competitive inhibitors of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, a rate-limiting step of the mevalonate pathway) reduce proliferation of theca-interstitial cells in vitro and decrease serum androgen levels in women with PCOS. The present study evaluated the effect of simvastatin on rat ovarian theca-interstitial cell steroidogenesis. Because actions of statins may be due to reduced cholesterol availability and/or isoprenylation of proteins, the present study also investigated whether steroidogenesis was affected by cell- and mitochondrion-permeable 22-hydroxycholesterol, isoprenylation substrates (farnesyl-pyrophosphate [FPP] and geranylgeranyl-pyrophosphate [GGPP]), as well as selective inhibitors of farnesyltransferase (FTI) and geranylgeranyltransferase (GGTI). Theca-interstitial cells were cultured for 12, 24, and 48 h with or without simvastatin, GGPP, FPP, FTI, GGTI, and/or 22-hydroxycholesterol. Simvastatin decreased androgen levels in a time- and concentration-dependent fashion. This inhibitory effect correlated with a decrease in mRNA levels of Cyp17a1, the gene encoding the key enzyme regulating androgen biosynthesis. After 48 h, GGPP alone and FPP alone had no effect on Cyp17a1 mRNA expression; however, the inhibitory action of simvastatin was partly abrogated by both GGPP and FPP. The present findings indicate that statin-induced reduction of androgen levels is likely due, at least in part, to the inhibition of isoprenylation, resulting in decreased expression of CYP17A1.


Assuntos
Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Ovário/citologia , Sinvastatina/farmacologia , Esteroide 17-alfa-Hidroxilase/antagonistas & inibidores , Esteroide 17-alfa-Hidroxilase/metabolismo , Alquil e Aril Transferases/antagonistas & inibidores , Animais , Células Cultivadas , Farnesiltranstransferase/antagonistas & inibidores , Feminino , Hidroxicolesteróis , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Fosfatos de Poli-Isoprenil/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Sesquiterpenos/metabolismo , Esteroide 17-alfa-Hidroxilase/genética , Especificidade por Substrato
13.
Fertil Steril ; 96(5): 1252-8, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21907337

RESUMO

OBJECTIVE: To examine the mechanisms of action of resveratrol and its interaction with simvastatin on growth and the mevalonate pathway in rat theca-interstitial cells. DESIGN: In vitro study. SETTING: Research laboratory. ANIMAL(S): Immature Sprague-Dawley female rats. INTERVENTION(S): Theca-interstitial cells were cultured in the absence or presence of resveratrol, simvastatin, mevalonic acid, farnesyl pyrophosphate, and/or geranylgeranyl pyrophosphate. MAIN OUTCOME MEASURE(S): DNA synthesis was assessed by thymidine incorporation assay; 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) expression and activity were evaluated with the use of quantitative real-time polymerase chain reaction, Western blot analysis, and HMGCR activity assay. Cholesterol synthesis was determined by the conversion of [(14)C]-acetate to [(14)C]-cholesterol. RESULT(S): Resveratrol potentiated the simvastatin-induced inhibition on cell proliferation in a concentration-dependent manner. Inhibitory effects of resveratrol were partly abrogated by the addition of mevalonic acid, farnesyl pyrophosphate, and geranylgeranyl pyrophosphate. Resveratrol reduced HMGCR expression and activity, and decreased cholesterol synthesis. In contrast, simvastatin inhibited HMGCR activity with a compensatory increase in HMGCR expression. Resveratrol counteracted this effect of simvastatin on HMGCR expression but augmented the simvastatin-induced inhibition on HMGCR activity and cholesterol synthesis. CONCLUSION(S): Resveratrol inhibits the mevalonate pathway via distinctly different mechanisms than statins. These observations demonstrate a novel mechanism of action of resveratrol and underscore the potential translational/clinical relevance of resveratrol interactions with simvastatin.


Assuntos
Proliferação de Células/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Ácido Mevalônico/metabolismo , Sinvastatina/farmacologia , Estilbenos/farmacologia , Células Tecais/efeitos dos fármacos , Animais , Western Blotting , Células Cultivadas , Colesterol/biossíntese , Replicação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Feminino , Hidroximetilglutaril-CoA Redutases/metabolismo , Fosfatos de Poli-Isoprenil/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Resveratrol , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sesquiterpenos/metabolismo , Células Tecais/metabolismo
14.
J Clin Endocrinol Metab ; 95(7): 3453-9, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20427495

RESUMO

CONTEXT: Statins are competitive inhibitors of 3-hydroxy-3methylglutaryl-coenzyme A reductase, with antimitotic, antioxidant, antiinflammatory, and immunomodulatory properties. Recent studies have shown that statins reduce the growth of human endometrial stromal (HES) cells and protect from the development of endometriosis in animal models. OBJECTIVES: The present study was conducted to evaluate the effects of simvastatin on apoptosis and cytoskeleton of HES cells. DESIGN AND SETTING: In vitro experiments were performed in the university research laboratory. PATIENTS: HES cells were obtained from endometrial biopsies collected from nine subjects in the proliferative phase of their menstrual cycle. MAIN OUTCOME MEASURES: The effect of simvastatin (10 and 30 mum) and/or geranylgeranyl pyrophosphate (GGPP, 30 mum) on caspase 3 and 7 activity, DNA fragmentation, and HES cell morphology was evaluated. RESULTS: Simvastatin induced significant time- and concentration-dependent apoptotic effects on HES cells as determined by increased activity of executioner caspases and DNA fragmentation. Simvastatin also caused profound alterations in HES cell morphology and F-actin cytoskeleton. This effect was abrogated by geranylgeranyl pyrophosphate, an important product of the mevalonate pathway. CONCLUSIONS: Simvastatin induces apoptosis and disruption of the cytoskeleton of HES cells by reducing isoprenylation in cultures of human endometrial stroma. The present findings may lead to the development of novel treatments for endometriosis involving statins.


Assuntos
Apoptose/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Endométrio/citologia , Endométrio/efeitos dos fármacos , Sinvastatina/farmacologia , Adolescente , Adulto , Análise de Variância , Caspase 3/metabolismo , Caspase 7/metabolismo , Forma Celular , Citoesqueleto/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Endométrio/metabolismo , Feminino , Imunofluorescência , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Pessoa de Meia-Idade , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo
15.
Mol Hum Reprod ; 16(4): 251-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20067985

RESUMO

Polycystic ovary syndrome (PCOS) is characterized by ovarian dysfunction and associated with ovarian theca-interstitial (T-I) cell hyperplasia, hyperinsulinemia, systemic inflammation and oxidative stress. This in vitro study tested whether rat T-I cell growth with or without insulin can be altered by resveratrol, a natural polyphenol with anti-carcinogenic, anti-inflammatory, anti-proliferative and antioxidant properties. Rat T-I cells were cultured with and without resveratrol and/or insulin, and the effects on DNA synthesis, number of viable cells and markers of apoptosis were evaluated. Resveratrol alone induced a potent concentration-dependent inhibition of cell growth by inhibiting DNA synthesis, decreasing the number of viable cells and increasing the activity of executioner caspases 3 and 7; these effects of resveratrol counteracted the pro-proliferative and anti-apoptotic effects of insulin. Immunofluorescence analysis of cells incubated with resveratrol showed concentration- and time-dependent morphological changes consistent with apoptosis. The present findings indicate that resveratrol promotes apoptosis to reduce rat T-I cell growth in vitro as well as inhibiting insulin-induced rat T-I cell growth. This suggests a possibility that resveratrol and/or mechanisms mediating its effect may be relevant to the development of novel treatments for PCOS, which is characterized by both excessive ovarian mesenchyma growth and hyperinsulinemia.


Assuntos
Anticarcinógenos/farmacologia , Apoptose/efeitos dos fármacos , Estilbenos/farmacologia , Células Tecais/citologia , Células Tecais/efeitos dos fármacos , Animais , Caspases/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Fragmentação do DNA/efeitos dos fármacos , Feminino , Marcação In Situ das Extremidades Cortadas , Ratos , Resveratrol
16.
Hepatology ; 51(3): 932-41, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19957376

RESUMO

UNLABELLED: We tested the hypothesis that the pathogenesis of alcoholic liver injury is mediated by epigenetic changes in regulatory genes that result from the induction of aberrant methionine metabolism by ethanol feeding. Five-month-old cystathionine beta synthase heterozygous and wild-type C57BL/6J littermate mice were fed liquid control or ethanol diets by intragastric infusion for 4 weeks. Both ethanol-fed groups showed typical histopathology of alcoholic steatohepatitis, with reduction in liver S-adenosylmethionine (SAM), elevation in liver S-adenosylhomocysteine (SAH), and reduction in the SAM/SAH ratio with interactions of ethanol and genotype effects. Hepatic endoplasmic reticulum stress signals including glucose-regulated protein-78 (GRP78), activating transcription factor 4, growth arrest and DNA damage-inducible gene 153 (GADD153), caspase 12, and transcription factor sterol response element binding protein-1c (SREBP-1c) were up-regulated in ethanol-fed mice with genotype interactions and negative correlations with the SAM/SAH ratio. Immunohistochemical staining showed reduction in trimethylated histone H3 lysine-9 (3meH3K9) protein levels in centrilobular regions in both ethanol groups, with no changes in trimethylated histone H3 lysine-4 levels. The chromatin immunoprecipitation assay revealed a decrease in levels of suppressor chromatin marker 3meH3K9 in the promoter regions of GRP78, SREBP-1c, and GADD153 in ethanol-treated heterozygous cystathionine beta synthase mice. The messenger RNA expression of the histone H3K9 methyltransferase EHMT2 (G9a) was selectively decreased in ethanol-fed mice. CONCLUSION: The pathogenesis of alcoholic steatohepatitis is mediated in part through the effects of altered methionine metabolism on epigenetic regulation of pathways of endoplasmic reticulum stress relating to apoptosis and lipogenesis.


Assuntos
Retículo Endoplasmático/genética , Epigênese Genética , Fígado Gorduroso Alcoólico/etiologia , Homocistinúria/genética , Homocistinúria/metabolismo , Fígado/ultraestrutura , Estresse Fisiológico/genética , Animais , Chaperona BiP do Retículo Endoplasmático , Etanol/administração & dosagem , Fígado Gorduroso Alcoólico/genética , Fígado Gorduroso Alcoólico/metabolismo , Camundongos
17.
Biol Reprod ; 81(5): 850-5, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19571257

RESUMO

Statins are competitive inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, a rate-limiting step of the mevalonate pathway. The pleiotropic effects of statins may be due to inhibition of cholesterol synthesis, as well as decreased availability of several biologically important intermediate components of the mevalonate pathway, including two substrates for isoprenylation (farnesyl pyrophosphate [FPP] and geranylgeranyl pyrophosphate [GGPP]). Recently, we demonstrated statin-induced inhibition of ovarian theca-interstitial cell proliferation in vitro, as well as reduction of testosterone levels in women with polycystic ovary syndrome (PCOS). This study evaluates the relative contribution of inhibition of isoprenylation and/or cholesterol availability to the modulation of theca-interstitial proliferation. Rat theca-interstitial cells were cultured in chemically defined media with or without simvastatin, FPP, GGPP, squalene, and/or two membrane-permeable forms of cholesterol (25-hydroxycholesterol and 22-hydroxycholesterol). Simvastatin inhibited DNA synthesis and the count of viable cells. The effects of simvastatin were partly abrogated by FPP and GGPP but not by squalene or cholesterol. Inhibition of farnesyl transferase and geranylgeranyl transferase reduced cell proliferation. The present findings indicate that simvastatin inhibits proliferation of theca-interstitial cells, at least in part, by reduction of isoprenylation. These observations provide likely mechanisms explaining clinically observed improvement of ovarian hyperandrogenism in women with PCOS.


Assuntos
Proliferação de Células/efeitos dos fármacos , Prenilação/fisiologia , Sinvastatina/farmacologia , Células Tecais/efeitos dos fármacos , Análise de Variância , Animais , Contagem de Células , Células Cultivadas , Relação Dose-Resposta a Droga , Feminino , Hidroxicolesteróis/farmacologia , Hipolipemiantes/farmacologia , Fosfatos de Poli-Isoprenil/farmacologia , Prenilação/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Sesquiterpenos/farmacologia , Células Tecais/fisiologia
18.
Am J Med Genet B Neuropsychiatr Genet ; 147B(6): 990-5, 2008 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-18186041

RESUMO

Schizophrenia is characterized by heritable deficits in executive function. Two common, functional polymorphisms, catechol-O-methyltransferase (COMT) Val108/158Met and methylenetetrahydrofolate reductase (MTHFR) C677T, have separately been associated with executive function performance in schizophrenia. Given the closely related biochemistry of MTHFR and COMT, it is plausible that the T and Val alleles act synergistically to impair executive function. This investigation of 185 outpatients with schizophrenia examined the interactive effects of these two polymorphisms on Wisconsin Card Sorting Task (WCST) performance. Two WCST measures consistently associated with schizophrenia, perseverative errors and inability to generate categories, were contrasted among compound COMT-MTHFR genotype groups. Individuals homozygous for the COMT Val allele who also carried at least one copy of the MTHFR T allele exhibited a significantly higher percentage of perseverative errors than patients in the other genotype groups. While the T allele also exerted a negative effect on category generation, COMT genotype did not contribute to category performance. It is plausible that cumulative effects of the MTHFR T and COMT Val alleles on intracellular methylation profiles and prefrontal dopamine transmission underlie their interactive effect on perseverative errors.


Assuntos
Catecol O-Metiltransferase/genética , Cognição/fisiologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo de Nucleotídeo Único/fisiologia , Esquizofrenia/fisiopatologia , Adulto , Substituição de Aminoácidos/fisiologia , Metilação de DNA , Dopamina/metabolismo , Epigênese Genética/fisiologia , Feminino , Genótipo , Humanos , Masculino , Metionina/genética , Pessoa de Meia-Idade , Modelos Biológicos , Esquizofrenia/genética , Psicologia do Esquizofrênico , Transmissão Sináptica/genética , Valina/genética
19.
Res Dev Disabil ; 29(1): 70-82, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17161583

RESUMO

This article examines the effects of mainstreaming on the attitudes of non-disabled students, in a secondary school, toward people with disabilities. Responses from 389 Form 1 and Form 2 students were analyzed. A 47-item Students' Attitudes toward People with a Disability Scale was used to measure student attitudes at the beginning and end of the school year. The effect of educational intervention and daily classroom contacts on student attitudes was examined. The competitive and achievement orientation of Hong Kong's educational environment poses formidable barriers to the adoption of effective inclusive practices in the classroom. The results of this study indicate that educational intervention outside the classroom has a small effect in changing students' attitudes.


Assuntos
Atitude Frente a Saúde , Deficiências do Desenvolvimento/psicologia , Pessoas com Deficiência/psicologia , Inclusão Escolar , Estudantes/psicologia , Transtorno Autístico/psicologia , Criança , Comportamento Infantil , Feminino , Humanos , Masculino , Grupo Associado , Pessoas com Deficiência Auditiva/psicologia , Comportamento Social , Inquéritos e Questionários
20.
Biol Psychiatry ; 63(1): 42-8, 2008 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17543893

RESUMO

BACKGROUND: Folate deficiency may contribute to negative symptoms in schizophrenia, but the underlying mechanism remains uncertain. We examined whether the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C functional polymorphisms contribute to negative symptoms. METHODS: Outpatients with schizophrenia (n = 200) were evaluated with the Positive and Negative Syndrome Scale (PANSS). Subjects also provided a blood sample for MTHFR genotype and serum chemistries. Comparisons of PANSS symptoms, folate, and homocysteine status were conducted based on genotype. RESULTS: The 677T allele load was associated with negative symptom severity. Contrary to our expectations, the T allele was also found to be protective against positive symptoms. The A1298C polymorphism did not contribute to negative symptoms, and only weakly to positive symptoms. The specific effects of the C677T polymorphism were confirmed with haplotype analysis. Among patients homozygous for the 667T allele, serum folate levels correlated with negative symptom severity. CONCLUSIONS: Increased MTHFR 677T allele load confers risk for negative symptoms in schizophrenia, while reducing severity of positive symptoms. Further, the biochemical interaction of low serum folate with 677T-variant MTHFR may induce downstream effects salient to the expression of negative symptoms.


Assuntos
Sintomas Comportamentais/genética , Predisposição Genética para Doença , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo Genético/genética , Esquizofrenia/genética , Psicologia do Esquizofrênico , Adulto , Análise de Variância , Sintomas Comportamentais/etiologia , Análise Mutacional de DNA/métodos , Feminino , Frequência do Gene , Genótipo , Homocisteína/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Ácidos Pteroilpoliglutâmicos/sangue , Risco , Esquizofrenia/complicações
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