OBJECTIVETo study the growth-inhibitory and apoptosis-inducing effects of realgar nanometer suspension in human carcinoma cervical cell Siha line, and the effect on HPV16E6/E7 oncogene expression.

METHODA " micro-jet efflux" strategy was used for the preparation of realgar nanometer suspension. Siha cells were treated with various concentrations (6.25, 12.5, 25, 50 mg x L(-1)) of realgar nanometer suspension for different hours (12, 24, 48, 72 h). The effect of realgar nanometer suspension on Siha cell growth suppression was detected by MTT method. Special morphological changes of apoptosis were observed by light and transmission electron microscopy (TEM) and DNA fragments electrophoresis. The apoptotic rates were quantified by flow cytometry (FCM). The expression of HPV16E6/E7 mRNA was assayed by RT-PCR.

RESULTAfter being treated with 25-50 mg x L(-1) realgar nanometer suspension for 48, 72 h, the survival of Siha cells decreased, and the rate of apoptosis markedly increased. With TEM and DNA electrophoresis, the special morphological changes were found. The apoptotic rates of Siha cells treated with realgar nanometer suspension were significantly higher than those in the control group (P < 0.01). G0-G1 phase arrest appeared following the treatment with realgar nanometer suspension in 25 and 50 mg x L(-1) 48 h. RT-PCR assay revealed that realgar nanometer suspension reduced HPV16E6/E7 gene expression.

CONCLUSIONRealgar nanometer suspension can inhibit the proliferation of human carcinoma cervical cell Siha line and induce the cell apoptosis. The mechanism may be related to the down-regulation of HPV16E6/E7 oncogene expression.