Enhanced sensitivity of human hepatoma cells to 5-fluorouracil by small interfering RNA targeting Bcl-2.

This study was designed to reveal whether the apoptosis induced in human hepatocellular carcinoma (HCC) cell lines by 5-fluorouracil (5-FU) could be enhanced by transfecting Bcl-2 small interfering RNA (siRNA). Bcl-2 siRNA and control siRNA were transfected into cells following treatment with or without 5-FU. Suppression of Bcl-2 expression was confirmed by Western blotting; cell viability was evaluated by MTS assay, and the occurrence of apoptosis in cells was evaluated by apoptosis assay. Expression of Bcl-2 protein after transfection of 20 nM Bcl-2 siRNA was significantly lower than that of control. Incubation of all cell lines with Bcl-2 siRNA reduced cell viability 96 h after 5-FU treatment compared with all other controls: Huh-7 (P < 0.01), Huh-7 with hepatitis C replicon (P < 0.01), HepG2 (P < 0.01), HLE (P < 0.05). Moreover, the proportion of apoptosis in control siRNA, Bcl-2 siRNA, control siRNA prior to 5-FU treatment, and Bcl-2 siRNA prior to 5-FU treatment groups were (4.6 +/- 2.3)%, (7.5 +/- 0.5)%, (6.0 +/- 2.1)%, and (19.5 +/- 0.86)%, respectively. The Bcl-2 siRNA prior to 5-FU treatment group showed the strongest effect of inducing apoptosis. In conclusion, the combination Bcl-2 siRNA and 5-FU might represent a new therapeutic option for HCC.