Primary research on arsenic trioxide inhibiting human breast cancer cells growth and its mechanisms

Abstract

The study was to research the biological effect and mechanisms of arsenic trioxide (As2O3) on human breast cancer cell line MDA-MB-231. The cytotoxicity was observed by MTT assay. Apoptosis was detected with Annexin V-FITC + PI dual parameter. Cell cycle and positive rate of proliferation cell nuclear antigen (PCNA), apoptosis associated protein Fas and bcl-2 and intracellular calcium ions (IECa(2+)) levels were measured by flow cytometry. As2O3 could inhibit the growth of MDA-MB-231 cells dramatically. There was obvious dosage-effect correlation (r = 0.99, P < 0.01), its half inhibitory concentration (IC(50)) was 6.65 micromol/L. Apoptosis was observed in MDA-MB-231 cells treated with As2O3. As2O3 could increase Fas expression and IECa(2+) levels and decrease PCNA expression in MDA-MB-231 cells (P < 0.01). Cell cycle was arrested in S + G(2)/M phase, but bcl-2 protein expression were not affected (P > 0.05). As2O3 could inhibit the growth of MDA-MB-231 cells dramatically and induce apoptosis. We proposed that its mechanisms were probably associated with the improved Fas expression and IECa(2+) levels and decreased PCNA expression and cell cycle arrest.