Abstract: ObjectiveTo investigate the cytotoxic effects and the induction of apoptois of curcumin on purinary bladder UMUC2 cancer cell lines in vitro;and develop an effective nontoxic intravesical agent that may be used immediately after bladder tumor resection to prevent the implantation of tumor cells and recurrence. significant clinical advancement. Methods UMUC2 cells were incubated with 0 to 160 μmol/L curcumin for 1 to 48 h. The cell viability was determined by MTT and clonal assay.The morphology of apoptotic cells was assessed by fluorescence microscopy after acridine orange/ethidium bromide (AO/EB) staining.Quantification of apoptosis and detection of cell cycle redistribution were evaluated by flow cytometry.The expression of apoptosis-associated protein p53 and Survivin was detected by immunocytochemical staining. Results Curcumin with different concentration could significantly result in the cell growth suppression.At the 160 μmol/L dose of curcumin was completely lethal to the UMUC2 cell lines after 1h treatment on clonal growth assay.Fluorescence microscopy and FCM revealed that the condensation and fragmentation of their nuclei and sub-G1 region after curcumin treatment respectively.The later also revealed cell phase arrest induced by curcumin was G2/M phase arrest mainly with significant decrease of S phase.Immunocytochemical staining revealed that the anti-apoptotic p53 and Survivin protein was down-regulated by the curcumin treatment. Conclusion Curcumin can suppress the growth,induce apoptosis of bladder cancer UMUC2 cell in vitro.These results suggested that the inhibition of p53 and survivin expression in UMUC2 cells might account for the mechanism of curcumin-induced apoptosis.At the 160 μmol/L concentration of curcumin is a potent cytotoxic agent against the UMUC2 bladder tumor cell lines.Taken together,our present findings showed the promising anti-cancer efficacy of curcumin against human bladder cancer cells,especially,as an intravesical agent.