Methylation status of p16 INK4A tumor suppressor gene in Iranian patients with sporadic breast cancer

p16 (INK4A) is a tumor suppressor encoding the Cdk inhibitor protein, which acts to repress Cdk4/6 and pRb phosphorylation. p16 (INK4A) gene can be inactivated by a variety of events, including promoter hypermethylation. To investigate the methylation status of the p16 (INK4A) gene in Iranian patients with breast carcinoma, promoter methylation was studied by methylation-specific PCR (MSP) and restriction enzyme-related PCR (REP). In addition, p16 (INK4A) promoter was analyzed by PCR-SSCP in order to detection of mutation and single nucleotide polymorphisms. Analysis of 70 patients by MPS and REP showed hypermethylation of p16 (INK4A) promoter in 35.7% (25/70) and 40% (28/70) of samples, respectively. Comparison of the molecular data and pathological information of the samples suggested that p16 (INK4A) gene might be inactivated at the early stages in breast cancer. Therefore, it could be suggested that hypermethylation of p16 (INK4A) promoter is one of the epigenetic factors affecting the progress of sporadic breast carcinogenesis in Iranian patients.