Methylation status of p16INK4A tumor suppressor gene in Iranian patients with sporadic breast cancer

Introduction   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. Materials and methods  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. Results  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. Conclusion  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.