Screening of the Stable Expressing HPV18 E5 Protein Cell Line and its Influence on Cell Proliferation and the Cell Cycle / 病毒学报

ABSTRACT

We wished to screen the cell line that stably expresses the HPV18E5 protein, and to ascertain the influence of HPV18E5 protein on cell proliferation and the cell cycle. The HPV18E5 gene was amplified by the polymerase chain reaction. Then, the His-tag pSecTag-HPV18E5 eukaryotic expression vector was constructed by digestion ligation and connection. The recombinant plasmid was transfected into Balb/c3T3 cells with lipofectamine, and positive cell lines were screened by a culture medium containing bleomycin. HPV18E5 expression in cells was confirmed by western blotting and immuno-enzymatic methods. The influence of HPV18E5 on cell proliferation and the cell cycle were detected by Cell Counting Kit-8 and flow cytometry, respectively. The pSecTag-HPV18E5 eukaryotic expression vector was constructed. After 21-day selection in a culture medium containing 400 μg/mL bleomycin, stably expressing HPV18E5 protein cells were harvested. Compared with control groups, cell proliferation in HPV18E5 stably expressed cells was obviously increased, as was the S phase in the cell cycle. Our results suggested that HPV18E5 influences cell proliferation and the cell cycle. Our study has laid the foundation of the biologic properties of HPV18E5 protein, which will aid further studies on the mechanism of action of carcinogenesis.