Fig. 4

Overexpression of circAKT3 increases the resistance of CDDP-sensitive GC cells to cisplatin in vitro. a The expression levels of circAKT3 and AKT3 mRNA in SGC7901 and BGC823 cells after stable transfection of circAKT3 or empty vector plasmids were detected by RT-qPCR. b Relative cell viability of circAKT3 or vector-transfected SGC7901 cells exposed to CDDP at the indicated concentrations for 48 h. c Colony-forming ability of SGC7901 cells transfected with circAKT3 or vector in the absence (Vehicle) or presence of CDDP (1.5 μM) for 48 h. d The apoptosis rates of SGC7901 cells transfected with circAKT3 or vector after CDDP (1.5 μM) treatment for 48 h were detected by flow cytometry. e Western blot analysis of apoptotic proteins in SGC7901 cells transfected with circAKT3 or vector upon CDDP (1.5 μM) treatment for 48 h (GAPDH was used as the loading control). f Immunofluorescence staining of γH2AX foci in SGC7901 cells transfected with circAKT3 or vector at 2 h after CDDP treatment (1.5 μM). Scale bars, 10 μm. g Percentage of cells containing > 10 γH2AX foci in SGC7901 cells transfected with circAKT3 or vector at 0 to 8 h after CDDP (1.5 μM) treatment. h Western blot analysis of γH2AX and BRCA1 expression in SGC7901 cells transfected with circAKT3 or vector after CDDP treatment (1.5 μM) removal. The results are presented as the mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001