Aberrant promoter methylation in p53 and ATM genes was not associated with sporadic breast carcinogenesis in Bulgarian patients

Abstract

Epigenetic silencing of gene expression has become an intensively studied topic regarding breast cancer during the last years. Previous investigations have shown that hypermethylation in gene promoters is an alternative to mutations cancer-related mechanism for inactivation of tumor suppressor gene function. The present study was designed for evaluation of promoter methylation in p53 and ATM tumor suppressor genes in Bulgarian patients with sporadic breast cancer. Sodium bisulfite conversion and methylation-specific PCR were performed on tumor DNA isolated from 55 patients with sporadic breast cancer. The data showed normal profile of methylation in the promoter region of p53 and ATM genes in all studied patients. Cases with hypermethylation were not observed. Our results did not support the involvement of p53 and ATM promoter hypermethylation in the neoplastic pathways of sporadic breast cancer. The lack of promoter hypermethylation in p53 and ATM is suggestive of a greater share of genetic aberrations in loss of tumor suppressor function of these genes and presumes the involvement of other epigenetic cancer mechanisms. To our knowledge this study provides the first data on promoter hypermethylation status of p53 and ATM genes in Bulgarian patients.

Keywords

• p53
• ATM
• breast cancer
• DNA hypermethylation