Methylation of E-cadherin and hMLH1 genes in Indian sporadic breast carcinomas

Abstract

Hypermethylation of promoter regions leading to inactivation of tumor suppressor genes is a common event in the progression of several tumor types. We have employed a novel restriction digestion based multiplex PCR assay to analyse the methylation status of promoter regions of tumor suppressor genes (p16, hMLH1, MGMT and E-cadherin) in sporadic breast carcinomas of Indian women. The present results indicated the absence of hypermethylation in promoter region of p16 and MGMT genes. However, 6 of the 19 (31.6%) sporadic breast carcinomas showed hypermethylation in the promoters of two of the genes analysed; three in hMLH1 and another three in E-cad. Since our earlier studies have shown lack of genetic alterations such as missense mutations and deletions in the tumor associated genes-p16, ras and p14^ARF in sporadic breast tumors, the epigenetic alterations of the two genes reported in the present study could be of interest and might be among the events in the genesis/progression of sporadic breast carcinomas.