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2.
J Clin Oncol ; 41(33): 5151-5162, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37607324

RESUMEN

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.


Asunto(s)
Carcinoma de Células Acinares , Neoplasias Pancreáticas , Masculino , Humanos , Carcinoma de Células Acinares/genética , Neoplasias Pancreáticas/genética , Proteína BRCA2/genética , Proteína BRCA1/genética , Mutación de Línea Germinal , Predisposición Genética a la Enfermedad , Recombinación Homóloga , Genómica , Neoplasias Pancreáticas
3.
Mol Diagn Ther ; 26(6): 645-653, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36178671

RESUMEN

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.


Asunto(s)
Proteína BRCA1 , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Proteína BRCA1/genética , Carcinoma Ductal Pancreático/genética , Neoplasias Pancreáticas/genética , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Mutación de Línea Germinal , Metilación de ADN , Regiones Promotoras Genéticas , Neoplasias Pancreáticas
4.
J Mol Diagn ; 22(3): 368-375, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31881335

RESUMEN

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.


Asunto(s)
Metilación de ADN , Epigenómica , Estudio de Asociación del Genoma Completo , Secuenciación de Nucleótidos de Alto Rendimiento , Homólogo 1 de la Proteína MutL/genética , Regiones Promotoras Genéticas , Islas de CpG , Epigenómica/métodos , Femenino , Estudio de Asociación del Genoma Completo/métodos , Estudio de Asociación del Genoma Completo/normas , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Masculino , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
5.
Cancer Res ; 79(6): 1047-1053, 2019 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-30643016

RESUMEN

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.


Asunto(s)
Biomarcadores de Tumor/análisis , Neoplasias Colorrectales/genética , Metilación de ADN , Homólogo 1 de la Proteína MutL/genética , Proteínas de Fusión Oncogénica/análisis , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Neoplasias Colorrectales/patología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Inestabilidad de Microsatélites , Persona de Mediana Edad , Mutación , Metástasis de la Neoplasia , Proteínas de Fusión Oncogénica/genética , Pronóstico , Regiones Promotoras Genéticas
6.
BMC Med Genomics ; 10(1): 33, 2017 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-28526081

RESUMEN

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.


Asunto(s)
Análisis Mutacional de ADN/métodos , Predisposición Genética a la Enfermedad , Mutación de Línea Germinal , Proteínas de Neoplasias/genética , Neoplasias/metabolismo , Proteína de la Poliposis Adenomatosa del Colon/genética , Proteínas de la Ataxia Telangiectasia Mutada/genética , Proteína BRCA1/genética , Proteína BRCA2/genética , Biomarcadores de Tumor/genética , Quinasa de Punto de Control 2/genética , Variaciones en el Número de Copia de ADN , Humanos , Neoplasias/genética , Polimorfismo de Nucleótido Simple , Reproducibilidad de los Resultados , Proteína 2 del Complejo de la Esclerosis Tuberosa , Proteína p53 Supresora de Tumor/genética , Proteínas Supresoras de Tumor/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética
7.
JCO Precis Oncol ; 20172017.
Artículo en Inglés | MEDLINE | ID: mdl-30211344

RESUMEN

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.
Fertil Steril ; 98(6): 1563-73, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22959450

RESUMEN

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.


Asunto(s)
Células de la Granulosa/citología , Células de la Granulosa/fisiología , Estilbenos/administración & dosificación , Inhibidores de la Angiogénesis/administración & dosificación , Animales , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Células de la Granulosa/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Resveratrol
9.
Endocrinology ; 153(8): 4019-29, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22719052

RESUMEN

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.


Asunto(s)
Ovario/citología , Estilbenos/farmacología , Células Tecales/efectos de los fármacos , Células Tecales/metabolismo , Animales , Western Blotting , Células Cultivadas , Femenino , Espectrometría de Masas , Ratas , Ratas Sprague-Dawley , Reacción en Cadena en Tiempo Real de la Polimerasa , Resveratrol , Esteroides/metabolismo
10.
J Clin Endocrinol Metab ; 95(7): 3453-9, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20427495

RESUMEN

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.


Asunto(s)
Apoptosis/efectos de los fármacos , Citoesqueleto/efectos de los fármacos , Endometrio/citología , Endometrio/efectos de los fármacos , Simvastatina/farmacología , Adolescente , Adulto , Análisis de Varianza , Caspasa 3/metabolismo , Caspasa 7/metabolismo , Forma de la Célula , Citoesqueleto/metabolismo , Fragmentación del ADN/efectos de los fármacos , Endometrio/metabolismo , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Persona de Mediana Edad , Células del Estroma/efectos de los fármacos , Células del Estroma/metabolismo
11.
Mol Hum Reprod ; 16(4): 251-9, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20067985

RESUMEN

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.


Asunto(s)
Anticarcinógenos/farmacología , Apoptosis/efectos de los fármacos , Estilbenos/farmacología , Células Tecales/citología , Células Tecales/efectos de los fármacos , Animales , Caspasas/metabolismo , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Fragmentación del ADN/efectos de los fármacos , Femenino , Etiquetado Corte-Fin in Situ , Ratas , Resveratrol
12.
Hepatology ; 51(3): 932-41, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19957376

RESUMEN

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.


Asunto(s)
Retículo Endoplásmico/genética , Epigénesis Genética , Hígado Graso Alcohólico/etiología , Homocistinuria/genética , Homocistinuria/metabolismo , Hígado/ultraestructura , Estrés Fisiológico/genética , Animales , Chaperón BiP del Retículo Endoplásmico , Etanol/administración & dosificación , Hígado Graso Alcohólico/genética , Hígado Graso Alcohólico/metabolismo , Ratones
13.
Alcohol Clin Exp Res ; 31(7): 1231-9, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17577393

RESUMEN

BACKGROUND: To demonstrate a causative role of abnormal methionine metabolism in the pathogenesis of alcoholic steatosis, we measured the effects on hepatic lipid synthesis of supplementing ethanol and folate-deficient diets with S-adenosylmethionine (SAM), a metabolite that regulates methionine metabolism. METHODS: Yucatan micropigs were fed folate-deficient diets as control, with ethanol at 40% of kcal, and with ethanol supplemented with SAM at 0.4 g/1,000 kcal for 14 weeks. Histopathology, triglyceride levels and transcripts, and protein levels of the regulatory signals of hepatic lipid synthesis were measured in terminal omental adipose and liver samples. RESULTS: Feeding ethanol at 40% of kcal with folate-deficient diets for 14 weeks increased and supplemental SAM maintained control levels of liver and plasma triglyceride. Serum adiponectin, liver transcripts of adiponectin receptor-1 (AdipoR1), and phosphorylated adenosine monophosphate kinase-beta (p-AMPKbeta) were each reduced by ethanol feeding and were sustained at normal levels by SAM supplementation of the ethanol diets. Ethanol feeding activated and SAM supplementation maintained control levels of ER stress-induced transcription factor sterol regulatory element-binding protein-1c (SREBP-1c) and its targeted transcripts of lipid synthesizing enzymes acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and glycerol-3-phosphate acyltransferase (GPAT). CONCLUSIONS: Ethanol feeding with a folate-deficient diet stimulates hepatic lipid synthesis by down-regulating adiponectin-mediated pathways of p-AMPK to increase the expression of nSREBP-1c and its targeted lipogenic enzymes. Preventing abnormal hepatic methionine metabolism by supplementing ethanol diets with SAM reduces liver triglyceride levels by up-regulation of adiponectin-mediated pathways to decrease fatty acid and triglyceride synthesis. This study demonstrates that ethanol-induced hepatic lipid synthesis is mediated in part by abnormal methionine metabolism, and strengthens the concept that altered methionine metabolism plays an integral role in the pathogenesis of steatosis.


Asunto(s)
Etanol/farmacología , Hígado Graso Alcohólico/etiología , Conducta Alimentaria/fisiología , Deficiencia de Ácido Fólico/metabolismo , Alimentos Formulados , Lípidos/biosíntesis , Hígado/efectos de los fármacos , S-Adenosilmetionina/farmacología , Quinasas de la Proteína-Quinasa Activada por el AMP , Adiponectina/metabolismo , Animales , Regulación hacia Abajo/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Etanol/administración & dosificación , Etanol/efectos adversos , Grasa Intraabdominal/metabolismo , Lipogénesis/efectos de los fármacos , Hígado/metabolismo , Metionina/administración & dosificación , Metionina/metabolismo , Apoyo Nutricional , Epiplón/metabolismo , Proteínas Quinasas/metabolismo , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Porcinos , Porcinos Enanos
14.
Am J Med Genet B Neuropsychiatr Genet ; 141B(8): 947-56, 2006 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-16917939

RESUMEN

Autism is a behaviorally defined neurodevelopmental disorder usually diagnosed in early childhood that is characterized by impairment in reciprocal communication and speech, repetitive behaviors, and social withdrawal. Although both genetic and environmental factors are thought to be involved, none have been reproducibly identified. The metabolic phenotype of an individual reflects the influence of endogenous and exogenous factors on genotype. As such, it provides a window through which the interactive impact of genes and environment may be viewed and relevant susceptibility factors identified. Although abnormal methionine metabolism has been associated with other neurologic disorders, these pathways and related polymorphisms have not been evaluated in autistic children. Plasma levels of metabolites in methionine transmethylation and transsulfuration pathways were measured in 80 autistic and 73 control children. In addition, common polymorphic variants known to modulate these metabolic pathways were evaluated in 360 autistic children and 205 controls. The metabolic results indicated that plasma methionine and the ratio of S-adenosylmethionine (SAM) to S-adenosylhomocysteine (SAH), an indicator of methylation capacity, were significantly decreased in the autistic children relative to age-matched controls. In addition, plasma levels of cysteine, glutathione, and the ratio of reduced to oxidized glutathione, an indication of antioxidant capacity and redox homeostasis, were significantly decreased. Differences in allele frequency and/or significant gene-gene interactions were found for relevant genes encoding the reduced folate carrier (RFC 80G > A), transcobalamin II (TCN2 776G > C), catechol-O-methyltransferase (COMT 472G > A), methylenetetrahydrofolate reductase (MTHFR 677C > T and 1298A > C), and glutathione-S-transferase (GST M1). We propose that an increased vulnerability to oxidative stress (endogenous or environmental) may contribute to the development and clinical manifestations of autism.


Asunto(s)
Trastorno Autístico/genética , Trastorno Autístico/metabolismo , Metionina/sangre , Estrés Oxidativo/genética , Adolescente , Trastorno Autístico/sangre , Catecol O-Metiltransferasa/genética , Niño , Preescolar , Cartilla de ADN , Femenino , Frecuencia de los Genes , Glutatión Transferasa/genética , Humanos , Masculino , Proteínas de Transporte de Membrana/genética , Metionina/metabolismo , Metilación , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Proteína Portadora de Folato Reducido , S-Adenosilhomocisteína/sangre , S-Adenosilmetionina/sangre , Transcobalaminas/genética
15.
Alcohol Clin Exp Res ; 30(7): 1262-70, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16792574

RESUMEN

BACKGROUND: Alcoholic liver disease is associated with abnormalities of methionine metabolic enzymes that may contribute to glutathione depletion. Previously, we found that feeding micropigs a combination of ethanol with a folate-deficient diet resulted in the greatest decreases in S-adenosylmethionine and glutathione and increases in liver S-adenosylhomocysteine and oxidized disulfide glutathione. METHODS: To study the mechanisms of glutathione depletion, we analyzed the transcripts and activities of enzymes involved in its synthesis and metabolism in liver and plasma specimens that were available from the same micropigs that receive folate-sufficient or folate-depleted diets with or without 40% of energy as ethanol for 14 weeks. RESULTS: Ethanol feeding, folate deficiency, or their combination decreased liver and plasma glutathione and the activities of hepatic copper-zinc superoxide dismutase and glutathione peroxidase and increased the activity of manganese superoxide dismutase and glutathione reductase. Hepatic levels of cysteine and taurine were unchanged while plasma cysteine was increased in the combined diet group. Cystathionine beta-synthase transcripts and activity were unaffected by ethanol feeding, while the activities of other transsulfuration enzymes involved in glutathione synthesis were increased. Glutathione transferase transcripts were increased 4-fold and its mean activity was increased by 34% in the combined ethanol and folate-deficient diet group, similar in magnitude to the observed 36% reduction in hepatic glutathione. CONCLUSIONS: Chronic ethanol feeding and folate deficiency acted individually or synergistically to affect methionine metabolism in the micropig by depleting glutathione pools and altering transcript expressions and activities of enzymes involved in its synthesis, utilization, and regeneration. The data suggest that the observed decrease in hepatic glutathione during ethanol feeding reflects its increased utilization to meet increased antioxidant demands, rather than reduction in its synthesis.


Asunto(s)
Glutatión/metabolismo , Hepatopatías Alcohólicas/metabolismo , Porcinos Enanos/metabolismo , Animales , Antioxidantes/metabolismo , Hígado/enzimología , Plasma/enzimología , Porcinos
16.
Patient Educ Couns ; 60(2): 201-5, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16442461

RESUMEN

The self-help movement in Hong Kong has been gradually gaining its momentum in recent years. The primary purpose of the research was to give voice to the experiences and views of patients towards cancer care and to influence healthcare providers and policy makers to act on patients' agendas. Self-help groups and their members are mobilized through the research activities of focus groups, interviews and a patient forum to specify and act on their needs. This article describes the project and the participatory action research (PAR) strategies in the mobilization of, and collaboration with, patient groups in research design, data analysis, and dissemination of findings. The implications on healthcare practice, particularly within an era of reform and restructuring of the healthcare system, are discussed.


Asunto(s)
Servicios de Salud Comunitaria , Continuidad de la Atención al Paciente , Neoplasias/rehabilitación , Satisfacción del Paciente , Grupos de Autoayuda , Servicios de Salud Comunitaria/organización & administración , Investigación sobre Servicios de Salud/métodos , Hong Kong , Humanos , Sobrevivientes
17.
Am J Physiol Gastrointest Liver Physiol ; 289(1): G54-63, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15705656

RESUMEN

Previously, we showed that feeding micropigs ethanol with a folate-deficient diet promoted the development of hepatic injury while increasing hepatic levels of homocysteine and S-adenosylhomocysteine (SAH) and reducing the level of S-adenosylmethionine (SAM) and the SAM-to-SAH ratio. Our present goals were to evaluate mechanisms for hepatic injury using liver specimens from the same micropigs. The effects of ethanol feeding or folate-deficient diets, singly or in combination, on cytochrome P-450 2E1 (CYP2E1) and signal pathways for apoptosis and steatosis were analyzed using microarray, real-time PCR, and immunoblotting techniques. Apoptosis was increased maximally by the combination of ethanol feeding and folate deficiency and was correlated positively to liver homocysteine and SAH. Liver CYP2E1 and the endoplasmic reticulum stress signals glucose-regulated protein 78 (GRP78), caspase 12, and sterol regulatory element binding protein-1c (SREBP-1c) were each activated in pigs fed folate-deficient or ethanol diets singly or in combination. Liver mRNA levels of CYP2E1, GRP78, and SREBP-1c, and protein levels of CYP2E1, GRP78, nuclear SREBP, and activated caspase 12 each correlated positively to liver levels of SAH and/or homocysteine and negatively to the SAM-to-SAH ratio. The transcripts of the lipogenic enzymes fatty acid synthase, acetyl-CoA carboxylase, and stearoyl-CoA desaturase were elevated in the ethanol-fed groups, and each was positively correlated to liver homocysteine levels. The induction of abnormal hepatic methionine metabolism through the combination of ethanol feeding with folate deficiency is associated with the activation of CYP2E1 and enhances endoplasmic reticulum stress signals that promote steatosis and apoptosis.


Asunto(s)
Deficiencia de Ácido Fólico/genética , Deficiencia de Ácido Fólico/fisiopatología , Perfilación de la Expresión Génica , Hepatopatías Alcohólicas/genética , Hepatopatías Alcohólicas/fisiopatología , Animales , Apoptosis , Depresores del Sistema Nervioso Central/farmacología , Citocromo P-450 CYP2E1/genética , Retículo Endoplásmico/metabolismo , Etanol/farmacología , Deficiencia de Ácido Fólico/patología , Hígado/metabolismo , Hígado/patología , Hígado/fisiopatología , Hepatopatías Alcohólicas/patología , Metionina/metabolismo , Porcinos , Porcinos Enanos
18.
Patient Educ Couns ; 47(1): 13-21, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-12023096

RESUMEN

This paper reports the results of a qualitative study that examined the experiences of cancer patients with the intention of incorporating consumer perspectives into the development of quality cancer care in Hong Kong. Altogether, eight focus group interviews were conducted with a total of 41 cancer patients. The results indicate that patients lack clear guidance and support regarding the management of sequelae and surveillance against recurrence. Patients also raised concerns about the lack of access to information, and the lack of health care provider accountability. Any understanding of the scope and goals of follow-up cancer care is obscured when the healthcare environment is not conducive to good doctor-patient communication. Patients are calling for more explicit goals and clinical practice guidelines to serve as frames of reference for both patients and doctors.


Asunto(s)
Cuidados Posteriores/normas , Neoplasias/terapia , Satisfacción del Paciente , Cuidados Posteriores/psicología , Comunicación , Femenino , Grupos Focales , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/psicología , Educación del Paciente como Asunto , Relaciones Médico-Paciente , Recurrencia , Encuestas y Cuestionarios , Resultado del Tratamiento
19.
Eur J Pharmacol ; 434(1-2): 81-6, 2002 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-11755169

RESUMEN

Previous studies showed that cigarette smoking was closely associated with gastric ulceration. People usually smoke under stress conditions, and together, these could induce more gastric damage. In the present study, we aimed to study the effects of nicotine administration and its withdrawal on stress-induced gastric ulceration in rats. Male Sprague-Dawley rats were given nicotine (25 or 50 microg/ml) for 10 days and then withdrawn for 2, 4 or 6 days. They were subjected to cold-restraint stress for 2 h after nicotine treatment or after nicotine withdrawal, and then killed. The results indicated that both nicotine treatment and its withdrawal potentiated stress-induced gastric damage. The mucosal glutathione (GSH) and mucus levels were reduced by stress and decreased further by nicotine. The prostaglandin E(2) concentration remained unchanged. To conclude, the adverse effect of nicotine on stress ulceration was prostaglandin E(2)-independent but mediated by the depression of glutathione and mucus levels in the gastric mucosa.


Asunto(s)
Nicotina/toxicidad , Úlcera Gástrica/etiología , Estrés Fisiológico/complicaciones , Animales , Dinoprostona/análisis , Dinoprostona/fisiología , Femenino , Mucosa Gástrica/química , Mucosa Gástrica/efectos de los fármacos , Mucosa Gástrica/patología , Glutatión/análisis , Ratas , Ratas Sprague-Dawley
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