Interfering with glutathione S-transferase P1 induces lung cell damage under irradiation conditions / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the association and mechanism between glutathione S-transferase P1(GSTP1) and radiation-induced lung injury.Methods Two effective GSTP1 siRNAs were designed and synthesized.The normal lung epithelial cell line BEAS-2B cells were transfected with GSTP1 siRNA (experimental group,siRNA-1,siRNA-2) and negative control siRNA (negative control group,NC).Western blot was performed to detect the expression levels of GSTP1 protein and EMT-related proteins.CDNB was adopted to evaluate the activity of GSTs.DCFH-DA probe was used for incubation.Flow cytometry was conducted to detect the median fluorescence intensity (MFI) and cellular apoptosis.Annexin-v/PI staining was utilized for incubation.MTT assay was performed to measure the proliferation of BEAS-2B,and the growth curve was drawn based on the results.Results After radiation,compared with the NC group,the ROS level and MFI were significantly higher in experimental group (6774.66±399.60 vs.8759.00±256.96 vs.9967.67±735.11,P＜0.05).In the experimental group,the percentage of cellular apoptosis was remarkably higher than that in the NC group (12.3± 1.16 vs.17.38± 1.65 vs.22.88± 1.20,P＜0.05).MTT assay demonstrated that the OD values in the experimental group were significantly lower than that in the NC group everyday.Further more,the level of EMT process is higher in the experimental group.Conclusions Interfering with the GSTP1 expression in lung epithelial cells can increase the intracellular ROS level,increase the percentage of cellular apoptosis,and reduce the cell proliferation rate following γ-radiation.Besides,it can also promote the epithelial mesenchymal transition in lung epithelial cells.The down-regulation of GSTP1 protein expression level probably aggravates the radiationinduced lung cell injury and promotes the epithelial mesenchymal transition.