Methylation Status of p16 gene in Iraqi Colorectal Cancer Patients

Abstract

The CDKN2A gene (encode cyclin dependent kinase inhibitor 2A) is considered as a tumour suppressor gene involved in cell-cycle control, and methylation in promoter regions of this gene is a frequent event in CRC patients as it associated with the loss of p16 protein expression in cancer cells leading to gene silence. The methylation status of the p16 gene was examined in 35 samples of Iraqi colorectal cancers (primary carcinomas) and the five samples of Iraqi bowel inflammation patients using Methyl Sensitive High Resolution Melting and the correlation between the methylation status and the clinicopathological findings was evaluated. The results show aberrant methylation of the p16 gene was detected in 17 colorectal tumor samples out of the 35 (48.75% ) primary colorectal carcinomas but there no change in methylation status  was found, suggesting that the aberrant methylation of p16 was frequently observed in Iraqi colorectal carcinomas. The clinicopathological data were then correlated with these results. Significant differences were observed with age (p<0.01), tumour location (p<0.01), moderately differentiated (p<0.01)  and (T3) lymphatic invasion  (p<0.01). This study provides evidence for hypermethylation status p16 gene in CRC patients, which may serve as useful information on CRC cancer progression.