The methylation status of GSTP1, APC, and RASSF1 genes in human prostate cancer samples: Comparative analysis of diagnostic informativeness of MS-HRM and hybridization on the Illumina Infinium HumanMethylation450 BeadChip

Abstract

There is a clear need in molecular markers of prostate cancer (PC) that would specify stratification of patients into risk categories and serve as additional parameters to clinical prognostic factors. Altered DNA methylation status is one of molecular processes that occur during PC development. The gene methylation status may be evaluated in laboratory diagnostics by a PCR approach known as means of methylation-sensitive high resolution melting (MS-HRM) curve analysis. This method is particularly promising due to minimal amounts of DNA required for analysis (10 ng). To date, numerous data based on the use of Infinium HumanMethylation450 BeadChip (HM450) technology have been accumulated on DNA methylation in PC samples. However, it remains unclear whether the MS-HRM results are consistent with chip hybridization data. The aim of this study was to perform the comparative analysis of the diagnostic informativeness of MS-HRM and HM450 chip hybridization methods in determination of the methylation status of three genes GSTP1, APC, and RASSF1 in samples obtained from PC patients. The study has shown that using the MS-HRM method it is possible to discriminate PC tumor samples from samples of histologically unaltered prostate tissue by analyzing the methylation status of each gene. Analysis of chip hybridization data confirmed the results obtained by MS-HRM. Differences between tumor tissue and histologically intact tissue obtained from each PC patient in the methylation levels of GSTP1, APC, and RASSF1, determined by MS-HRM or chip hybridization were consistent with each other. Thus, the assessment of the methylation level of gene GSTP1, APC, and RASSF1 using MS-HRM can become the basis for the development of a laboratory test, the specifying diagnosis of prostate cancer.