Abstract: BACKGROUND AND AIM: To investigate the apoptosis in MDA-MB-231 cells induced by different concentrations of As2O3 and to study its influence on the activities of Survivin and Caspase-3 proteins. MATERIALS AND METHODS: The rate of apoptosis in human breast carcinoma MDA-MB-231 cells was detected by flow cytometry; the activities of Survivin and Caspase-3 proteins were examined by immunocytochemistry and Western blot in untreated and As2O3-treated MDA-MB-231 cells. RESULTS: The percentages of the apoptosis in MDA-MB-231 cells were (28.89±2.47)％,(46.73±3.82)％ and (56.44±4.16)％, in cells treated for 24 hours with 10.0，20.0，40.0 μmol/L As2O3 respectively. As2O3 inhibited the expression of Survivin protein and promoted the expression of Caspase-3 protein. There were obvious dose-effect correlations between As2O3 and its functions. CONCLUSION: The results suggested that As2O3 could induce apoptosis of MDA-MB-231 cells via Survivin protein inhibition and Caspase-3 protein promotion.

Key words: As2O3, MDA-MB-231 cells, apoptosis, Survivin, Caspase-3