Abstract: Objective To study the effects of ursolic acid (UA) on growth of the endometrial cancer cell line HHUA. MethodsThe HHUA cells were treated with ursolic acid at different concentrations. The proliferation inhibition was determined by MTT assay. Morphological examination and flow cytometry were used to determine the apoptosis. RTPCR and immunohistochemical method were used to determine the expressions of apoptosis related genes caspase-3 and bcl-2. The semiquantification of protein expression was analyzed by pathological imageanalysis. ResultsUA strongly inhibited the proliferation of HHUA cells. Apoptosis was induced by UA treatment. The morphology of HHUA showed changes such as chromatin aggregation, nuclear and cytoplasmic condensation and apoptotic body appearance. UA caused significant G0/G1 phases arrest with a concomitant decrease of cell population in S and G2/M phases. Apoptotic cells were found by flow cytometry. The maximal early apoptotic rate was (29.1±2.43)% when exposed to 40umol/L for 72?h. The expression of caspase-3 gene was enhanced while the expression of antiapoptotic gene bcl-2 was decreased. All these effects were in a dose- and time-dependent manner. Conclusion UA induces the apoptotic processes in the endometrial cancer HHUA cell line by involving the caspase-3 pathway and bcl-2 family proteins.

Key words: Ursolic acid, HHUA cell line, Apoptosis, Caspase-3, Genes, bcl-2