Inhibiting effect and its mechanism of BDH2 gene on the proliferation of liver cancer cells

Objective To investigate the inhibiting effect and its mechanism of β-hydroxybutyrate dehydrogenase 2 (BDH2) gene on the proliferation of liver cancer cells. Methods The lentiviral vectors expressing BDH2 were constructed. The liver cancer cell line HepG2-BDH2 stably expressing BDH2 (experimental group) and the control cell line HepG2-Vector (control group) were established. The expression levels of BDH2 mRNA in two groups were detected by RT-PCR. The proliferation of liver cancer cells in two groups was detected by CCK-8 assay. The colony formation ability of cells was observed in two groups by colony formation assay. The expression of BDH2 protein and apoptosis-associated protein Bcl-2 was detected by Western blot. The experimental data were compared using t test. Results In experimental group, the expression level of BDH2 mRNA was (2.20±0.10)×10-3, which was significantly higher than (0.20±0.01)×10-3 in control group (t=34.95, P<0.05). In experimental group, the A450 values at 3, 4, 5, 6 and 7 d after cell culture were 0.55±0.20, 0.73±0.02, 1.26±0.12, 1.62±0.14 and 2.19±0.12, which were significantly lower than 0.70±0.06, 1.13±0.08, 1.77±0.15, 2.45±0.12 and 3.02±0.15 in control group (t=-5.19, -11.34, -5.96, -10.35, -9.54; P<0.05), respectively. The cell proliferation curve showed that the proliferation of cells in experimental group was significantly weaker than that in control group. Colony formation assay indicated that the number of cell clones in experimental group was 184±7, which was significantly less than 429±15 in control group (t=-25.84, P<0.05). Compared with control group, the expression levels of BDH2 and cleaved caspase-3 protein in experimental group were up-regulated significantly, whereas the expression level of Bcl-2 protein was down-regulated significantly. Conclusions BDH2 gene can inhibit the proliferation of liver cancer cells probably through promoting the apoptosis of liver cancer cells via Bcl-2 signaling pathway. Key words: Carcinoma, hepatocellular; Cell proliferation; Apoptosis; BDH2 gene; Bcl-2