Fig. 2. YL064 inhibits constitutively active STAT3.

a, b U266 cells were treated with the indicated concentrations of YL064 for 24 h (a) or treated with YL064 (20 μM) for different times (b). Cells were collected and subjected to western blot analyses with specific antibodies against P-STAT3 (Tyr705), P-STAT3 (Ser727), and STAT3. c HeLa cells were transfected with p-STAT3-Luc and SV40-Renilla-Luc. Then, cells were treated with YL064 (20 μM) for 24 h, followed by stimulating with IL-6 for 20 min, and the luciferase activity were measured *p < 0.05, **p < 0.01. d U266 cells were treated with the indicated concentrations of YL064 for 6 h and STAT3 activity was examined by EMSA. e, f U266 cells were treated with YL064 (20 μM) for the indicated time points, and the mRNA level of cyclin D1, Mcl-1 were examined by RT-PCR and the indicated proteins were examined by western blot *p < 0.05, **p < 0.01