Figure 1. Melatonin prohibited cell proliferation and promoted apoptosis in UBUC cells. (A) An MTT assay was performed to detect the cell viability of the T24 and UMUC3 cells treated with melatonin at 0, 0.5, 1, and 2 mM for 24 hours. (B) The T24 and UMUC3 cells were exposed to 0, 0.5, 1, and 2 mM melatonin for 10 days and were quantitatively analyzed by a colony formation assay. The cell cycle distribution of (C, D) 24-hour and (E, F) 48-hour melatonin-treated UBUC cell lines was assessed by flow cytometry. (G) Hoechst 33342 staining was used to detect apoptotic cells in the melatonin-treated UBUC cells, and (H) the apoptotic rate of each group is shown. Bars represent as mean ± SD. *p < 0.05, **p < 0.01, ***p < 0.001.