[Overexpression of bcl-2 protects HCC-9204 hepatoma cells from ethanol-induced apoptosis]

To explore the effect of apoptosis-associated gene bcl-2 overexpression on ethanol-induced apoptosis in hepatocellular carcinoma (HCC) cells.

The plasmid of retrovirus expression vector pDOR-SB, which contains human bcl-2 cDNA, was transfected into a HCC cell line HCC-9204 cells whose bcl-2 protein expression is below detectable level. The expression of bcl-2 protein was detected by immunohistochemical ABC method. The cells were cloned continually until a monoclonal cell strain which expressed bcl-2 protein at a 100% positive rate was obtained, and the cells were detected with flow cytometry. After the above cells were treated with 6% ethanol for 6 h, the happening of apoptosis were detected by MTT assay, TUNEL assay and flow cytometry.

bcl-2 protein expression was detected in most of the cells which had been transfected with pDOR-SB, while it was bcl-2 protein negative in cells transfected with pDOR empty vector or non-transfected HCC-9204 cells. The obtained monoclonal cell strain expressed bcl-2 protein at a 100% positive rate under flow cytometer after being cloned 3 times in succession, and was named HCC-bcl-2. After being treated with 6% ethanol, the optical absorbance data of HCC-bcl-2 cells and non-transfected HCC-9204 cells detected by MTT assay were 0.519 +/- 0.053 and 0.366 +/- 0.046, respectively, the former was significantly higher than the latter (P < 0.01). Their TUNEL index was 0.387 and 0.613 respectively, and their sub-G1 apoptotic peak scale was 3.8% and 10.7% respectively, the former were all lower than the latter (P < 0.05).

Overexpression of bcl-2 protein can suppress ethanol-induced apoptosis in HCC-9204 hepatoma cells.