Abstract:

Objective  To discuss the effect of Human Papilloma Virus 16 early protein 5 （HPV16-E5）-targeted siRNA on Caski cells apoptosis induced by TNF-related apoptosis-inducing ligand(TRAIL)．Methods  HPV16-E5-targeted siRNA was transfected into Caski cells by lipofectamine. Forty-eight hours after the transfection， the expression of E5 mRNA was detected by RT- PCR； Cell apoptosis and caspase-8 activities in the blank control group,  siRNA-E5-treated group, TRAIL-treated group, siRNA-E5+TRAIL-treated group and negative RNA+TRAIL-treated group were determined by flow cytometry and caspase-8 Activity Assay Kit. The expressions of receptors DR4 and DR5 on cell surface after RNA interference were tested by Real-Time PCR and Western blotting. Results  RT-PCR revealed that the expression of HPV16-E5 mRNA in the siRNA-E5 group was significantly lower than that in the blank and the negative control groups(P<0.05)； The cell apoptosis rate in siRNA-E5+TRAIL group was significantly higher than that in the TRAIL group (P<0.05). There was no significant difference in cell apoptosis rate between the negative RNA+TRAIL group and the TRAIL group(P>0.05)； There was no difference in the expressions of receptors DR4 and DR5 after RNA interference (P>0.05)； The activity of caspase-8 in siRNA-E5+TRAIL group was higher than that in TRAIL group， and the difference was statistical significant(P<0.05). Conclusion  HPV16-E5-Targeted siRNA could enhance the apoptosis mediated by TRAIL against Caski cancer cells in vitro， and the mechanism may be related to the increase of caspase-8 activity.

Key words: Cervix neoplasms； TRAIL protein； siRNA；  Cell apoptosis； Caspase-8