FGFR inhibition enhances PTX-induced cell cycle arrest in mesenchymal-type UC cell lines. (A) T24, J82, RT4, and UMUC-14 cells were treated with 0, 0.1, 1, and 10 μM BJG398 for 3 days. IC50 values were calculated using CalcuSyn (BioSoft, Ferguson, MO, USA). Data represent mean ± standard deviation of five replicates. (B) Cells were exposed to increasing concentrations of PTX and BGJ398 combinations at a fixed ratio. Viable cells were assayed and CI was calculated using CalcuSyn software. Lines above each bar represent CI for that dose combination (n = 3). (C) Cell cycle distribution and apoptosis were analyzed by propidium iodide staining and flow cytometry. A total of 1 × 106 cells were seeded in a 60-mm plate and treated with indicated concentrations of PTX and BGJ398 for 48 h (n = 3). (D) Quantification of cell cycle distribution of T24, J82, RT4, and UMUC-14 cells.