Objectives: To examine the effects of arsenic trioxide (As2O3) on human endometrial carcinoma cell lines with respect to cytotoxicity and the induction of apoptosis and telomerase expression in vitro.
Methods: Four endometrial carcinoma cell lines (Ishikawa, ECC-1, RL-95-2 and Hec-1B) were treated with increasing concentrations of As2O3.
Results: As2O3 inhibited proliferation of all cell lines in a concentration and time-dependent manner (IC50 range of 3-7 microM). Coincident with the inhibition of growth, As2O3 also induced apoptosis in all cell lines as measured by the time-dependent increase in M30 antibody fluorescence (binds a caspase-cleaved epitope of cytokeratin 18) detected by flow cytometry, and reduced telomerase activity by decreasing the hTERT mRNA expression.
Conclusion: As2O3 may exert anti-tumor effects through the induction of the apoptosis pathway and telomerase and hTERT may play an important role in the anti-apoptotic effects which are observed when endometrial cancer cells are treated in vitro with As2O3.