Expression of E-cadherin gene and methylation of promoter in hepatocellular carcinoma

Objective To investigate the relationships between the expression of E-cadherin (E-cad) gene and the methylation of promoter CpG islands in hepatocellular carcinoma (HCC). Methods Specimens of tumor tissue and corresponding adjacent liver tissue were collected from 36 cases of hepatocellular carcinoma (HCC). The expression of E-cad mRNA was detected with RT-PCR technique,and the methylation of CpG islands for E-cad gene was determined with methylation-special PCR both in tumor tissues and adjacent normal liver tissues. Results The levels of E-cad mRNA expression were significantly lower in the HCC tumor tissues than those in corresponding adjacent tissues (P0.001). E-cad mRNA expression was lower in stage Ⅲ~Ⅳ cases than that in stage Ⅰ~Ⅱ cases (P=0.025); lower in tumors 5 cm in diameter with that in smaller tumors (P=0.035); lower in well-encapsulated tumors than that in the poor-encapsulated tumors (P=0.001). The frequency of methylation of CpG islands for E-cad gene was higher in the HCC tumor tissues than that in the corresponding non-tumor tissues (P=0.035); and lower in well-encapsulated tumors than that in the poor-encapsulated tumors tissues (P=0.015). The level of E-cad mRNA expression was significantly lower in the tumors with E-cad methylation than that in the tumors with E-cad non-methylation (P0.001). Conclusion Decreased E-cad mRNA expression may be involved in the pathogenesis of HCC,which is associated with aberrant methylation of E-cad gene.