Е.М. Kuznetcova, О.V. Shkabko, А.А. Raevskaya, S.L. Gorbunova, L.B. Gorshkova, S.Е. Severin, Е.S. Severin, А.Z. Vinarov

One of the most important tasks in maintaining of health in aging populations of modern society is early diagnosis and treatment of cancer, among which a special place belongs to prostate cancer (PCa). Over the past 10 years, the incidence of prostate cancer in Russia increased by more than 70 %. Currently, there is strong evidence of lack of diagnostic value of prostate-specific antigen (PSA). Thus, search for new markers of prostate cancer becomes urgent to improve diagnosis and treatment of this disease. One of the most widely described epigenetic abnormalities in tumor cells (including prostate) is changing of the methylation profile in promoter region of the GSTπ1 (Glutathione-S-Transferase π1) gene. Also, prostate tissue malignancy is accompanied by significant epigenetic changes observed among tumor suppressor genes such as RARβ2 (Retinoic Acid Receptor β2) and RASSF1A (RAS association domain family protein 1A). The purpose of this study was to develop a method for determining the methylation status of promoter regions of three genes involved in the development of prostate diseases, as well as identification of diagnostic indicators of the complex of markers for the early noninvasive diagnosis and monitoring of prostate disease. The simultaneous use of several DNA markers most relevant characterizes genetic changes in prostate tissue, which is important given the extreme heterogeneity and multifactorial nature of prostate cancer. Investigation of methylation status of promoter regions of genes GSTπ1, RARβ2 and RASSF1A conducted by methyl-specific PCR (MS-PCR) for different types of biological material taken from 135 patients with prostate pathologies of varying severity and 22 healthy volunteers. After the MS-PCR of three genes for all the available samples was done by semiquantitative evaluation of the promoter region methylation degree of genes under study and development of pathological process on the signal intensity of amplification product GC-rich regions of the promoter regions of studied genes. Then we calculated the sensitivity and specificity of the developed test system, as well as the predictive value of positive and negative tests. It was found that the level of abnormal methylation of promoter regions of genes GSTπ1, RARβ2 and RASSF1A increased during the development of prostate diseases compared with normal tissue and is correlated with the degree of pathology of the pancreas. Methylation status of promoter regions of genes GSTπ1, RARβ2, RASSF1A (total) is prognostically significant and has a high diagnostic accuracy and reliability in comparison with those used to date diagnostic markers of the disease. Based on these data, we can assume that the overall predictive value of selected molecular markers is comparable with that of PSA, which is determined in the serum. Thus, the combined use of these markers in clinical practice may lead to more accurate diagnosis of diseases of the pancreas.