The investigation of GSTP1, APC and RASSF1 gene promoter hypermethylation in urine DNA of prostate-diseased patients.

Prostate cancer (PCa) represents one of the most complicated human tumors and, like many others malignancies, arises from progressive genetic and epigenetic alterations. Among all recognized epigenetic alterations, aberrant DNA methylation (hypo- and hypermethylation) is the most important and the best characterized change in PCa. We analyzed GSTP1, APC and RASSF1 gene promoter hypermethylation in urine DNA of ten previously non-treated prostate-diseased patients. For the purpose, the quantitative real-time methylation specific PCR (MSP) with primers designed for amplification of methylated bisulfite-converted human DNA, followed by melting procedure, was currently optimized. GSTP1 gene promoter hypermethylation was detected in 2 and 1 out of 5 patients with biopsy-confirmed PCa using the primers covering the 3´ and 5´ CpG regions of the promoter, respectively. The APC gene promoter hypermethylation was found in neither of PCa or non-PCa patients and the RASSFI gene promoter hypermethylation was found in some non-PCa and not in all PCa patients. Our results suggest that GSTP1 gene promoter hypermethylation can be detected in urine DNA of PCa patients with real-time MSP followed by melting. This enables evaluation of its potential as a useful biomarker in the diagnosis and prognosis of PCa (Tab. 1, Fig. 1, Ref. 9).