Apoptosis inducing effects of arsenic trioxide on human bladder cancer cell line BIU-87

OBJECTIVE: To explore the apoptosis inducing effects of arsenic trioxide (As2O3) on human bladder cancer cells and elucidate possible mechanisms. METHODS: After treatment with As2O3, the growth inhibition rates of human bladder cancer cell line BIU-87 were studied by MTT and cell counts methods. DNA synthesis rates were detected by 3H-TdR assay. The morphological changes of cancer cells were observed by light and electronic microscopy and cell apoptosis rates were detected by TdT-mediated dUTP nick end labeling (TUNEL). bcl-2 gene expression of BIU-87 cells was observed by strept avidin-biotin complex (SABC) immunohistochemical method. RESULTS: As2O3 could effectively inhibit the growth of BIU-87 (P < 0.05), which were time and concentration dependent. The inhibition rate of 4.0 mumol/L As2O3 for DNA synthesis of cancer cells was 55.64% (P < 0.01). Partial cancer cells presented the characteristic morphological changes of apoptosis which depended on the time of exposure to drug (P < 0.05). bcl-2 expression of BIU-87 cells was decreased significantly (P < 0.05). CONCLUSION: As2O3 can significantly induce apoptosis in bladder cancer cells by down-regulating the expression of the bcl-2 gene and inhibiting DNA synthesis. This provides a potentially effective method for prevention and cure of human bladder cancer.