Figure 2. Compound 13i HCl exhibits anti-proliferative activity in bladder cancer cells. (A, B) RT112, T24 and SV-HUC-1 cells were exposed to the indicated concentrations of 13i HCl for 48 h and subjected to MTT assay (A) or SRB assay (B) to analyze cell viability and proliferation, respectively. Data are represented as mean ± S.D. (n=3) *P<0.05, **P<0.01, ***P<0.001 compared to control cells. (C, D) RT112 cells were treated with the indicated concentrations of 13i HCl and PF670462 in the presence of okadaic acid (2 μM) for 1 h and subjected to Western blotting by using CK1δ (C) and CK1ε (D) antibodies.