Role of Glutathione-S-Transferase P1 Hypermethylation in Molecular Detection of Prostate Cancer

Abstract

The aim of this study was to evaluate the diagnostic potential of the quantification of glutathione-S-transferase P1 (GSTP1) gene hypermethylation in molecular detection of prostate cancer in tissue biopsies. One hundred fourteen male patients were enrolled in the study; 44 patients with histopathologically confirmed prostate adenocarcinoma, 20 patients with variable degrees of prostate intraepithelial neoplasia, and 50 with benign prostatic hyperplasia, who served as a control group. Real-time quantitative methylation-specific polymerase chain reaction was used for assessment of methylation of the promoter region of the GSTP1 gene. Methylation of the GSTP1 promotor was detected in 24% of patients with benign prostatic hyperplasia, 60% of patients with prostate intraepithelial neoplasia, and in 86.3% of prostate adenocarcinoma patients. A statistically significant difference in the GSTP1/MYOD1 (myogenic differentiation 1gene) methylation ratios among the three groups was observed (p=0.0001). At the cutoff value of 9, GSTP1/MYOD1 methylation ratios showed sensitivity in the detection of prostate adenocarcinoma of 71.8% and specificity of 96%. Methylation of the GSTP1 promotor is a common molecular alteration in prostate cancer that may be a useful adjunct to serum screening tests and digital rectal examination findings and the use of quantitative real-time methylation-specific polymerase chain reaction is a promising technique that often distinguishes malignant from nonmalignant prostate disease.