Fig. 3

Role of the NF-κB pathway in mediating K-Ras-induced CD137 expression. a, b Panc-1 and SW1990 pancreatic cancer cells were transfected with 100 nmol/L control siRNA or siRNA against p65 (RELA) for 48 h. CD137 mRNA was measured by real-time PCR. c T-Rex/K-Ras cells were first transfected with 100 nmol/L control siRNA or siRNA against p65 for 24 h, then incubated with doxycycline for 48 h. CD137 mRNA was measured by real-time PCR. d HCT116 cells were transfected with 100 nmol/L siRNA against p65 or control RNA (siCTL) for 48 h, and CD137 mRNA was measured by real-time PCR. Data are presented as mean ± SEM of three repeated experiments. Statistical analysis: two-tailed unpaired t-test for a–d. **P < 0.01; ***P < 0.001. CD137 tumor necrosis factor receptor superfamily member 9, Doxy doxycycline, siCTL control siRNA, sip65 siRNA against p65, PCR polymerase chain reaction