Promoter DNA Methylation of Oncostatin M receptor-β as a Novel Diagnostic and Therapeutic Marker in Colon Cancer

In addition to genetic changes, the occurrence of epigenetic alterations is associated with accumulation of both genetic and epigenetic events that promote the development and progression of human cancer. Previously, we reported a set of candidate genes that comprise part of the emerging “cancer methylome”. In the present study, we first tested 23 candidate genes for promoter methylation in a small number of primary colon tumor tissues and controls. Based on these results, we then examined the methylation frequency of Oncostatin M receptor-β (OSMR) in a larger number of tissue and stool DNA samples collected from colon cancer patients and controls. We found that OSMR was frequently methylated in primary colon cancer tissues (80%, 80/100), but not in normal tissues (4%, 4/100). Methylation of OSMR was also detected in stool DNA from colorectal cancer patients (38%, 26/69) (cut-off in TaqMan-MSP, 4). Detection of other methylated markers in stool DNA improved sensitivity with little effect on specificity. Promoter methylation mediated silencing of OSMR in cell lines, and CRC cells with low OSMR expression were resistant to growth inhibition by Oncostatin M. Our data provide a biologic rationale for silencing of OSMR in colon cancer progression and highlight a new therapeutic target in this disease. Moreover, detection and quantification of OSMR promoter methylation in fecal DNA is a highly specific diagnostic biomarker for CRC

Induktie van HLA klasse II-antigenen door cytokines Een fysico-chemische studie van humaan interferon-gamma

KULeuven Campusbibliotheek Exacte Wetenschappen / UCL - Université Catholique de LouvainSIGLEBEBelgiu

Afzonderen van een mediator die de expressie van HLA klasse-2-antigenen induceert

KULeuven Campusbibliotheek Exacte Wetenschappen / UCL - Université Catholique de LouvainSIGLEBEBelgiu

Promoter Methylation Primarily Occurs in Tumor Cells of Patients with Non-small Cell Lung Cancer

Background: The distribution of promoter methylation throughout the lungs of patients with non-small cell lung cancer (NSCLC) is unknown. In this explorative study, we assessed the methylation status of the promoter region of 11 genes in brush samples of 3 well-defined endobronchial locations in patients with NSCLC and in brushes of former and current smokers without NSCLC. Materials and Methods: The methylation status of RASSF1A, GATA4, GATA5, SFRP1, RAR beta 2, DAPK, MGMT, p16, p14, CHFR and APC2 was determined in all samples using real-time methylation-specific PCR. Results: Ten patients with NSCLC and 18 non-NSCLC controls were included. Eight patients had one or more methylated genes in their tumor brush. Promoter methylation of genes in proximal or contralateral locations was much less frequent than in tumor brushes, and almost exclusively occurred in normal tissue if the same gene was also methylated in the tumor brush. Conclusion: Promoter methylation almost exclusively occurred in tumor cells of patients with NSCLC

FOXE1 and SYNE1 genes hypermethylation panel as promising biomarker in colitis associated colorectal neoplasia

Background: Colitis-associated colorectal cancer affects individuals with inflammatory bowel disease (IBD) more often and earlier than cancer in the general population. Colonoscopy provides the surveillance gold standard. Changes to the surveillance intervals depending on endoscopic activity have been made, given data demonstrating that this is an important predictor of future dysplasia or cancer, but adjuvant, noninvasive clinical tools are still warranted to improve surveillance outcomes and to assist in management and interpretation of dysplasia. Methylation markers may be able to do this. Methods: SYNE1, FOXE1, NDRG4, and PHACTR3 genes were screened using methylation-specific PCR that permit the methylation status of the genes to be determined directly on biopsies. Ninety-three patients with long-standing IBD undergoing a cancer surveillance program, and 30 healthy controls were studied. These included colorectal adenocarcinomas on a background of IBD of various stages (n = 25), IBD-associated dysplastic lesions (n = 29), adenomas arising on a background of ulcerative colitis (n = 8), samples from patients with no evidence of dysplasia or cancer but long-standing IBD (n = 31), and symptomatic patients found to have normal colonoscopy (controls) (n = 30). Results: Gene promotor hypermethylation of SYNE1 and FOXE1 genes varied significantly between the groups and was increasingly likely with increased disease severity. Neither occurred in controls, whereas promotor hypermethylation was detected in biopsies of 60% of patients with colitis-associated colorectal cancer for FOXE1 and 80% for SYNE1. Promotor hypermethylation of either gene was highly significantly different between the groups overall. Conclusions: FOXE1 and SYNE1 hypermethylation markers demonstrated significantly increased expression in neoplastic tissue. Promoter methylation analysis of these genes might be a useful marker of neoplasia in long-standing IBD