Objective: To investigate the change of Bcl-2 expression and telomerase during the apoptosis induced by oridonin on human hepatocelluar carcinoma BEL7402 cells.
Method: BEL-7402 cells in culture medium were given 8,16,24,32 micromol x L(-1) different concentrations of oridonin. The cell apoptotic rate was detected by flow cytometry (FCM), morphology of cell apoptosis was observed by Hoechst 3325 staining. Bcl-2 and Bax expressions were detected by Western blotting. Reverse transcriptase polymerase chain reaction (RT-PCR) and PCR enzyme-linked immunosorbent assay (ELISA) were used to detect hTERT mRNA expression and telomerase activity.
Result: Oridonin induced BEL-7402 cells apoptosis significantly, and the apoptosis rate was both in time-and dose-dependent manner. Marked morphological changes of cell apoptosis were observed very clearly by Hoechst 33258 staining after the cells exposed to oridonin for 60 hours; Western blotting showed that Bcl-2 expression was down-regulated and Bax expression up-regulated concurrently along with the apoptotic process, and the expression of hTERT mRNA as well as activity of telomerase were decreased concurrently.
Conclusion: Oridonin could decrease the expression of hTERT mRNA and telomerase activity as well as down-regulation of Bcl-2 and up-regulation of Bax expression during the apoptosis of BEL-7402 cells.