OBJECTIVETo study the effects and its mechanisms of arsenic trioxide (As2O3) on cell growth and human telomerase reverse transcriptase (hTERT) of human tongue cancer cells (Tca8113 cell line).

METHODSThe growth inhibition rates of Tca8113 by various concentrations of As2O3 were detected by MTF method. Cell apoptosis was detected by FCM labeled with Annexin V-FITC. hTERT gene expression was detected by RT-PCR method. hTERT protein of Tca8113 cells was determined by Western blot assay.

RESULTSThe results showed that As2O3 could inhibit the growth of Tca8113 effectively and apoptotic rate of Tca8113 cells was obviously increased in a dose and time-dependent manner. (83.40 +/- 7.31)% cells treated with 5 micromol/L As2O3 were inhibited on 72 hour point, the early apoptosis rate reached on 26.40% +/- 3.42% at that time. Moreover hTERT mRNA and protein were decreased depended on the dose and time of As2OC3, mRNA expressions of hTERT in test groups were greatly lower than that of control group on 72 hour point.

CONCLUSIONIt was suggested that As2O3 could significantly inhibit the growth of Tca8113 cells by inducing causing cell apoptosis and down-regulating the expression of hTERT mRNA gene and protein which might be one of its action mechanisms.