[Investigation of the e-cadherin promoter methylation in patients with colorectal cancer in Iran]

ABSTRACT

E-cadherin is widely down-regulated and tightly associated with tumor invasion and metastasis in multiple human cancer types. Recent studies have shown that aberrant methylation of the E-cadherin gene promoter contributes to its silencing. However, information regarding epigenetic inactivation of E-cadherin in colorectal cancer is insufficient. Herein, we correlate association of the methylation of the ECadherin promoter with pathological features of colorectal cancer as well as history and demographic data. We used methylation specific polymerase chain reaction [MSPCR] to examine methylation status of the 5' CpG island of E-cadherin along with its expression by using RT-PCR following surgical resection of 66 unrelated patients with colorectal cancer. Results showed that 35 out of 66 tumor DNA samples [53%] showed aberrant methylations. In contrast, all normal tissues were unmethylated. The obtained results show a similarity with the Japanese [54.5%] and Greek [55.7%] populations. The results have confirmed methylation of this gene in sporadic colorectal cancer cases [40.8%] in the Iranian population by researchers in Shiraz. These data suggest that epigenetic silencing via aberrant methylation of the E-cadherin promoter plays a critical role in the inactivation of this tumor suppressor gene in colorectal cancer.