Figure 2
Rap1 is involved in TRF2-mediated etoposide resistance in gastric cancer cells. (a) Rap1 siRNA vectors were transfected into SGC7901/VCR, respectively. Rap1 expression after treated with 20 μg/ml of etoposide for 6 h was detected by western blot and real-time PCR analysis. *P<0.0001 vs SGC7901/VCR and SGC7901/VCR-Cont. (b) Rap1 siRNA vector and TRF2 eukaryotic expression vector were cotransfected into SGC7901. TRF2 and Rap1 expression after treated with 20 μg/ml of etoposide for 6 h were detected by western blot and real-time PCR analysis. *P<0.0001 and **P<0.0001 vs SGC7901 and SGC7901-Cont. (c) IC50 values (μg/ml) of gastric cancer cells for etoposide. The sensitivity of gastric cancer cells to etoposide was evaluated using MTT assay as described in Materials and Methods section. The concentration of etoposide that caused a 50% reduction in number of colonies (IC50) was calculated. *P<0.01 vs SGC7901/VCR and SGC7901/VCR-Cont; **P<0.01 vs SGC7901–TRF2 and SGC7901-Cont.
