OBJECTIVETo investigate the apoptosis in MA-891 cells induced by different concentrations of As2O3 and to study its influence on the activity of telomerase and telomerase mTERT-mRNA, which provide theoretical and experimental basis for breast carcinoma.

METHODThe MA-891 breast carcinoma cell lines were used as the object. Different concentration of As2O3 was cultivated with MA-891 cells, and the growth inhibition of MA-891 cells was analyzed by MTT. The rate of apoptosis in MA-891 cells was detected by flow cytometry. The telomerase activity was determined by TRAP-PAGE-SILVER staining and was analyzed by specific soft ware. The expression mTERT-mRNA was examined by RT-PCR assay in untreated and As2O3-treated cells.

RESULTAs2O3 could inhibit the growth of MA-891 cells remarkably; the IC50 value of As2O3 for MA-891 was 9.68 micromol x L(-1) and 5.50 micromol x L(-1) respectively during 24,48 h. The percentage of the apoptosis in MA-891 cells was 30.21%, 48.26%, 57.43%, as the cells were treated with 5, 10, 20 micromol x L(-1) As2O3 for 24 hours. Treated with As2O3 for 24 hand 48 h, the telomerase activity of MA-891 cells was inhibited remarkably, which showed obvious time and concentration dependence. The mTERT-mRNA expression of MA-891 cells were significantly inhibited when treated with As2O3 for 24 h and 48h.

CONCLUSIONAs2O3 could remarkably inhibit the growth of MA-891 cells and could promote the apoptosis of the cells. Treated with As2O3, the activities of telomerase and telomerase mTERT-mRNA were inhibited remarkably and were obvious dosage-effect correlation.