title: Radiosensitivity in HeLa cervical cancer cells overexpressing glutathione S-transferase π 1.
abstract: The aims of the present study were to investigate the effect of overexpressed exogenous glutathione S-transferase π 1 (GSTP1) gene on the radiosensitivity of the HeLa human cervical cancer cell line and conduct a preliminarily investigation into the underlying mechanisms of the effect. The full-length sequence of humanGSTP1was obtained by performing a polymerase chain reaction (PCR) using primers based on the GenBank sequence ofGSTP1.Subsequently, the gene was cloned into a recombinant eukaryotic expression plasmid, and the resulting construct was confirmed by restriction analysis and DNA sequencing. A HeLa cell line that was stably expressing high levels ofGSTP1was obtained through stable transfection of the constructed plasmids using lipofectamine and screening for G418 resistance, as demonstrated by reverse transcription-PCR. Using the transfected HeLa cells, a colony formation assay was conducted to detect the influence ofGSTP1overexpression on the cell radiosensitivity. Furthermore, flow cytometry was used to investigate the effect ofGSTP1overexpression on cell cycle progression, with the protein expression levels of the cell cycle regulating factor cyclin B1 detected using western blot analysis. Colony formation and G2/M phase arrest in theGSTP1-expressing cells were significantly increased compared with the control group (P<0.01). In addition, the expression of cyclin B1 was significantly reduced in theGSTP1-expressing cells. These results demonstrated that increased expression ofGSTP1inhibits radiosensitivity in HeLa cells. The mechanism underlying this effect may be associated with the ability of the GSTP1 protein to reduce cyclin B1 expression, resulting in significant G2/M phase arrest.
authors.affiliation: Department of Oncology, Changhai Hospital, Second Military Medical University, Shanghai 200433, P.R. China.
authors.forename: Liang
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Anesthesiology, Fuzhou General Hospital, Fuzhou, Fujian 350025, P.R. China.
authors.forename: Ren
authors.initials: R
authors.lastname: Liu
authors.affiliation: Second Department of Hepatic Internal Medicine, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai 200438, P.R. China.
authors.forename: Hong-Bin
authors.initials: HB
authors.lastname: Ma
authors.affiliation: Department of Oncology, Changhai Hospital, Second Military Medical University, Shanghai 200433, P.R. China.
authors.forename: Ming-Zhen
authors.initials: MZ
authors.lastname: Ying
authors.affiliation: Department of Oncology, Changhai Hospital, Second Military Medical University, Shanghai 200433, P.R. China.
authors.forename: Ya-Jie
authors.initials: YJ
authors.lastname: Wang
keywords: cell cycle; glutathione S-transferase π 1; human cervical cancer; radiosensitivity