Growth arrest-specific gene 2 suppresses hepatocarcinogenesis by intervention of cell cycle and p53-dependent apoptosis

Figure 4 GAS2 inhibits HCC cell growth by increasing p53-mediated apoptosis. A: Effect of GAS2 overexpression on apoptosis was determined by FACS using the Annexin V-APC apoptosis assay. A: The effect of 100 μM etoposide (Eto) in SK-Hep1 cells transfected with pDEST40-CTRL or pDEST40-GAS2 (^aP < 0.05 vs control); (B) Effect of knocking down GAS2 in MIHA on apoptosis was determined by FACS using the Annexin V-APC apoptosis assay. The effect of 100 μM etoposide (Eto) in MIHA cells transfected with siCTRL or siGAS2 (^aP < 0.05 vs control); C: Expression of p53 in hepatocytes and HCC cell lines was identified by western blotting, β-actin was used as loading control; D: siRNA-mediated knockdown of p53 (sip53) and overexpression of GAS2 in SK-Hep1 cells as well as the apoptosis markers such as cleaved caspase-3 and cleaved PARP were confirmed by western blotting; E: Effect of knocking down p53 (siP53) and overexpression of GAS2 in SK-Hep1 cells on apoptosis was determined by FACS using the Annexin V-APC apoptosis assay (^bP < 0.01 vs control; mean values and SD from three replicate experiments); F: Cell apoptosis markers in the absence or presence of etoposide (Eto) in GAS2-overexpressing SK-Hep1 cells (left panel) or GAS2-ablated MIHA cells (right panel). FACS: Fluorescence-activated cell sorting; GAS2: growth arrest-specific gene 2.