Effect of ionizing radiation and cisplatin on the expression of TOB1 in human lung cancer cell lines

Abstract

Objective To explore the effect of ionizing radiation and cisplatin on the expression of Transducer of erbB2,1 ( TOB1 ) in human lung adenocareinoma SPCA-1 and LTEP-α-2 cell lines.Methods SPCA-1 and/or LTEP-α-2 cells were respectively irradiated with 2,4,6,8,and 10 Gy X-rays generated by a linear accelerator (with the source skin distance of 100 cm and dose rate of 200 cGy/min).The cell molecular samples were subtracted at 6,12,18,and 24 h after 6 Gy irradiation.For X-rays and cisplatin combination treatment,cells were divided into radiation group (6 Gy X-rays),cisplatin group (20 mol/L cisplatin),and combination group (6 Gy X-rays + 20 mol/L cisplatin).SPCA-1 and LTEP-α-2 cells without any treatment were used as control group.The relative levels of TOB1 mRNA and protein expression were detected by rigorously controlled semi-quantitative RT-PCR and Western blot analysis with quantitation of the mRNA/protein bands by densitometry.Results The expression level of TOB1 was significantly increased in both mRNA and protein level after radiation exposure (t =8.25-24.48,P ＜0.05).For time-dependent induction of TOB1,the expression was significantly increased 6 h after X-rays exposure (t =14.23-15.82,P ＜ 0.05 ).More significant increase of TOB1 expression was identified after the combination treatment of X-rays and cisplatin,compared to that of the radiation and/or cisplatin treatment alone (t =11.21-13.67,P ＜0.05).Conclusions lonizing radiation and cisplatin could upregulate the expression of TOB1 in lung cancer cells in both mRNA and protein levels.TOB1 may be a molecular target for ionizing radiation and cisplatin treatment in lung cancer and it may have potential implication in evaluating the curative efficiency of chemo-and radio-therapy. Key words: Lung cancers; Ionizing radiations; Cisplatin; Transducer of erbB2. 1