ABSTRACT
OBJECTIVE: To evaluate the usefullness of examination of methylation status of selected tumor-supressor genes in early diagnosis of ovarian cancer. DESIGN: Prospective clinical study. SETTING: Department of Gynecology and Obstetrics, Department of Molecular Biology, Jessenius Medical Faculty, Commenius University, Martin, Slovak Republic. METHODS: In this study we analyzed hypermethylation of 5 genes RASSF1A, GSTP, E-cadherin, p16 and APC in ovarian tumor samples from 34 patients - 13 patients with epithelial ovarian cancer, 2 patients with border-line ovarian tumors, 12 patients with benign lesions of ovaries and 7 patients with healthy ovarian tissue. The methylation status of promoter region of tumor-supressor genes was determined by Methylation Specific Polymerase Chain Reaction (MSP) using a nested two-step approach with bisulfite modified DNA template and specific primers. RESULTS: Gene methylation analysis revealed hypermethylation of gene RASSF1A (46%) and GSTP (8%) only in malignant ovarian tissue samples. Ecad, p16 and APC genes were methylated both in maignant and benign tissue samples. Methylation positivity in observed genes was present independently to all clinical stages of ovarian cancer and to tumor grades. However, there was observed a trend of increased number and selective involvement of methylated genes with increasing disease stages. Furthermore, there was no association between positive methylation status and histological subtypes of ovarian carcinomas. CONCLUSION: RASSF1A and GSTP promoter methylation positivity is associated with ovarian cancer. The revealed gene-selective methylation positivity and the increased number of methylated genes with advancing disease stages could be considered as a useful molecular marker for early detection of ovarian cancer. However, there is need to find diagnostic approach of specifically and frequently methylated genes to determining a methylation phenotype for early detection of ovarian malignancies.
Subject(s)
DNA Methylation , Genes, Tumor Suppressor , Ovarian Neoplasms/genetics , Adult , Aged , Carcinoma, Ovarian Epithelial , Female , Humans , Middle Aged , Neoplasms, Glandular and Epithelial/genetics , Polymerase Chain Reaction , Promoter Regions, GeneticABSTRACT
UNLABELLED: Breast cancer is one of the most common cancer affecting women and the recent research is focused on identifying new genetic and epigenetic prognostic and predictive factors. Glutathione S-transferase P1 (GSTP1) is abiotransformation enzyme expressed in normal breast epithelial cells which can be epigenetically inactivated in breast cancer. We have shown, that application of nested two-stage methylation-specific PCR (MSP) is asuitable method for analysis of epigenetically silenced GSTP1 in formalin-fixed paraffin-embedded (FFPE) tissues from breast cancer patients. Of 45 breast tumors, 11 (24, 4%) were found to have methylated GSTP 1promoter region. We were able to demonstrate the correlation between the hypermethylation of the GSTP1 promoter region and histological grade of the tumor (p KEYWORDS: breast cancer, prognostic factors, hypermethylation, GSTP1, methylation-specific PCR.
Subject(s)
Breast Neoplasms/genetics , DNA Methylation , Glutathione S-Transferase pi/genetics , Promoter Regions, Genetic , Adult , Aged , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Female , Humans , Middle Aged , Prognosis , Receptors, Estrogen/analysisABSTRACT
Prostate cancer is one of the most common malignant diseases in men above the age of 50. A genetic predisposition and/or acquired genetic and epigenetic changes together with lifestyle contribute to the development of the disease. The most studied epigenetic modification in prostate cancer is the methylation of the cytosine located within the dinucleotide CpG of promoter regions of different genes by methylation specific PCR. The evidence of gene silencing by DNA methylation in genes like GSTP1, APC or RASF1 is a common and relatively specific event in prostate cancer. DNA methylation testing can be performed on tissue samples or urine, ejaculate or serum. Translational research is searching for new biomarkers for early detection and prognosis of prostate cancer, but because of large methodological differences in applied techniques and patient cohorts, the investigations have yielded promising, but also some controversial results. More prospective randomized trials and standardized methods are needed to assess the true value of methylation for the diagnosis and prognosis of prostate cancer.