Inhibition of human papillomavirus type 16 E6 gene expression with HPV16 E6 specific siRNA in cervical carcinoma cell line

Objective To study the HPV-16 E6 specific shRNA expressed by U6 plasmid to inhibit the expression of HPV oncogene and the growth of cervical cancer cell. Methods We selected 4 target mRNA sequences to the exon and interon of HPV-16 E6 mRNA, and synthesized dsDNA to construct the recombinant pSi-lencer1.0-U6 vector which expresses HPV-16 E6 short hairpin dsRNA. After transfected into HPV-16 DNA positive cervical cancer cell line CaSki, then observe the expression level of HPV-16 E6,E7 genes and their proteins as well as the inhibition effects of cell growth. Results The cellular growth velocity was down-regulated both by 4 HPV-16 E6 specific siRNA in 0-96 h after recombinant pSilencer1.0-U6 vector transfected into CaSki cell. The abundance of HPV-16 E6 E7 mRNA inside CaSki cells were also reduced by the 4 HPV-16 E6 specific siRNA respectively, while 1 HPV-16 E6 specific siRNA targetting to the interon sequence of E6 gene inhibited the HPV-16 E6 mRNA only. HPV-16 E6 protein was undetectable with Western blot assay 72 h later after 4 HPV-16 E6 specific siRNA transfected into CaSki cell. Conclusion It suggested that the growth of cervical cancer cells was inhibited by HPV-16 E6 specific siRNA. The HPV16 E6 specific siRNA targeting to the interon of E6 mRNA can inhibit the expression of HPV-16 E6 gene only, while the HPV-16 E6 specific siRNAs targeting to the exon of E6 mRNA can inhibit the expression of both E6 and E7 genes, which can be used as a good candidates of cancer therapeutical siRNA drug.