Expression of bcl-2 and p53 in induction of esophageal cancer cell apoptosis by ECRG2 in combination with cisplatin.

AIM To investigate the mechanisms of induction of apoptosis of esophageal cancer cells by esophageal cancer-related gene 2 (ECRG2) in combination with cisplatin (DDP). METHODS Hoechest staining was performed to analyze the effects of single ECRG2 and ECRG2 in combination with DDP on apoptosis of EC9706 cells. The expression levels of p53 and bcl-2 mRNA and protein were determined by RT-PCR and Western blotting, respectively. RESULTS The number of apoptotic cells after the treatment with ECRG2 in combination with DDP for 24 hours was more than that after the treatment with single ECRG2. RT-PCR and Western blotting showed that the expression levels of bcl-2 mRNA and protein were both down-regulated, while p53 mRNA and protein were both up-regulated in the cells treated with ECRG2 in combination with DDP compared with those given ECRG2 alone. CONCLUSION ECRG2 in combination with DDP can enhance the apoptosis of EC9706 cells, possibly by down-regulating bcl-2 expression and up-regulating p53.