Investigation of PTEN Promoter Methylation and Its Effect on Non-Small Cell Lung Carcinoma

Abstract

PTEN is a tumor suppressor gene with important roles in apoptosis. This gene is located on chromosome 10q23 and is one of the most frequently inactivated genes in cancers. Severe underexpression of PTEN has been reported in several types of cancer, including endometrial, prostate, breast, and brain cancer. Also, this gene is epigenetically silenced through aberrant hypermethylation of CpG islands on its promoter. The present study investigated the promoter methylation and expression levels of PTEN in patients with Non-Small Cell Lung Carcinoma (NSCLC). The study included 20 patients with NSCLC, whose bisulfite-treated DNA samples were investigated using the Methyl-Specific PCR (MSP) with primers specific for either methylated or non-methylated forms of PTEN. PTEN expression was also assessed using real-time PCR. 20 samples from NSCLC patients, 70% (n=14) showed PTEN underexpression, while 85% (n=17) had PTEN promoter methylation. Also, 12 of 17 (70%) samples with PTEN promoter methylation had concomitant PTEN underexpression. According to our results, there was a significant correlation between the PTEN promoter methylation and NSCLC. PTEN underexpression and promoter methylation were also significantly correlated.