Fig. 3. XIST suppresses cell growth while inducing apoptosis in HepG2 cells by antagonizing the cancer promoting effect of miR-155-5p. Cells were treated with cisplatin at indicated concentrations for 24 h before analysis. (A) Cell proliferation assay showing that increase in cell proliferation rate induced by miR-155-5p mimic transfection can be repressed by XIST knock-in. (B–D) XIST knock-in significantly reduced cell viability while increasing apoptosis and cisplatin susceptibility of HepG2 cells with or without miR-155-5p mimic transfection. (C) is a representative result of flow cytometry counting for the percentage of Annexin V positive cells in each group. (E–G) miR-155-5p mimic transfection decreased, while XIST knock-in increased, apoptosis-related protein parameters in HepG2 cells with or without cisplatin treatment. (G) is a representative result of Bim, Bax, and Bcl-2 protein expression levels in different groups. Semi-quantitative analysis of Western blot results was performed as described in Fig. 2. Western blot data were presented as fold-changes compared to that of a control group. ^*p<0.05, ^†p< 0.01, ^‡p<0.001, ^§p<0.0001. XIST, X-inactive specific transcript; JPX, just proximal to XIST; KI NC, knock-in control; XIST KI, XIST knock-in.