Fig. 3

Reversing effect of VPA in 786-M-R cells. a The metformin resistant 786-O cells (786-M-R) were incubated with increasing concentrations of metformin for 48 h. Cell viability (%) was compared with the corresponding untreated cells. The IC50 values of metformin were calculated by SPSS software. b 786-M-R cells were incubated with increasing concentrations of phenformin for 48 h. Cell viability (%) was compared with the corresponding untreated cells. The IC50 values of phenformin were calculated by SPSS software. c 786-M-R cells were cultured with VPA 1 mM (VPA), metformin 10 mM (Met) or a combination (VPA + Met), and the cell viability was examined at 24, 48 and 72 h. ^#P < 0.05 vs metformin group. d Confluent 786-M-R cells were starved for 18 h, scratched and grown in the presence of VPA, metformin or VPA + Met. Photos were taken at 200× magnification at the 0 h and 18 h. Bar, 50 μm. The cell numbers of groups were counted. *P < 0.05 vs control group, ^#P < 0.05 vs metformin group. e 786-M-R cells were treated by VPA, Met or VPA + Met for 24 h and 48 h then fixed by cold alcohol. The PI stained cells were detected by BD LSRFortessa to analyse the cell cycle distribution. Results were shown in bar graphs. *P < 0.05 vs control group, ^#P < 0.05 vs metformin group. f 786-M-R cells were treated with VPA, Met or VPA + Met for 48 h. The rates of apoptosis were determined and analysed. *P < 0.05 vs control group, ^#P < 0.05 vs metformin group