Objective: To explore the methylation status of T-cadherin promoter region in human esophageal carcinoma cell lines EC1 and EC109 and elucidate the effects of 5-azacytidine-2'-deoxycytidine (5-Aza-CdR) on their abilities of proliferation and invasion, the methylation status and the expression of T-cadherin.
Methods: The expression level of T-cadherin was measured by Western blot. And the methylation status of T-cadherin promoter region was analyzed by methylation-specific PCR (polymerase chain reaction), separately before and after a treatment of demethylating agent 5-Aza-CdR.
Results: The T-cadherin gene was hypermethylated in EC109 cells but semi-methylated in EC1 cells. After a treatment of 5-Aza-CdR, T-cadherin gene methylation was reversed. And the gene expression was strongly up-regulated in both cells. 5-Aza-CdR could decrease the proliferation and effectively inhibit the ability of cell invasion (P < 0.01).
Conclusion: The aberrant methylation in promoter region is an important mechanism of T-cadherin gene inactivation in human esophageal carcinoma cells. 5-Aza-CdR can increase the expression of T-cadherin by a reversal of hypermethylation and effectively inhibit the proliferation and invasion of tumor cells.