Objective   To observe the effect of HPV16 E6-targeted RNA interference (RNAi) on the invasion

metastasis ability and cell cycle of human nasopharyngeal carcinoma (NPC) cell line HNE-1 and investigate the feasibility of using HPV16 E6 gene as therapeutic target for treatment of NPC.    Methods   According to HPV16 mRNA sequence in the Genbank

the siRNA against HPV16 E6 were designed

synthesized and transfected into HNE-1 cells. The m

RNA and protein expression of HPV16 E6 were confirmed by RT-PCR and Western blotting

respectively. The invasion ability was determined by Transwell chamber. The cellular proliferation and cell cycle phase were examined respectively by MTT assay and flow cytometry analysis (FCM).    Results   The siRNA against HPV16 E6 downregulated the expression of mRNA and protein dramatically in HNE-1 cells

with a rate of 66.3% and 56.7% respectively (P0.05). The invasion assay demonstrated that the number of HNE-1 cells which crossed the membrane in siRNA transfection group (45.3±4.0) was significantly lower than that in negative control group (147.7±4.7) (P0.05). After transfection

the proliferation of HNE-1 cells were inhibited and there was a remarkable difference compared with the control group (P0.05). FCM showed that the cell cycle was arrested in the G

0

/G

1

phase.    Conclusion   siRNA against HPV16 E6 gene effectively inhibits the specific gene expression

and then restrain the invasion and metastasis ability of HNE-1 cells

inhibits cell proliferation

and induces cell cycle to redistribute.