三氧化二砷对人肺癌细胞株A2放射增敏的实验研究

Radiosensitization effect of arsenic trioxide on human lung cancer cell line A2

目的:本文探讨三氧化二砷(Arsenictrioxide,As2O3)对人肺癌细胞株A2放射敏感性的影响。方法:设立空白对照组、单纯照射组(直线加速器X射线照射,2 Gy)、As2O3组(1.0μmol/LAs2O3)、As2O3+照射组(1.0μmol/LAs2O3+X射线照射,2 Gy)。用流式细胞仪检测As2O3作用后肿瘤细胞周期的变化,MTT法及平板克隆形成试验测定各实验组人肺癌细胞株A2细胞存活分数和集落形成率,用流式细胞仪观察Bcl-2蛋白的表达。结果:As2O3作用后使A2细胞出现明显G2/M期阻滞。As2O3+照射组细胞存活分数和集落形成率较As2O3组及单纯照射组明显下降,与As2O3组或单纯照射组比较差异具有显著性(P<0.01)。As2O3+照射组细胞Bcl-2蛋白的表达明显下调,与As2O3组或单纯照射组比较差异具有显著性(P<0.01)。结论:As2O3对人肺癌细胞A2具有放射增敏作用,其增敏机制可能与As2O3增加照射前G2/M期细胞比例及照射后肿瘤细胞的凋亡率有关。

Objective：To explore the effect of arsenic trioxide on radiosensitivity in human lung cancer cell line A2.Methods： There were four groups in the study：control group（untreated group）,As2O3 group（1.0 μmol/L As2O3）,irradiation group,As2O3＋ irradiation group.Cellular response to irradiation was evaluated by the colony forming test and MTT assay;Flow cytometry was used to determined the Bcl-2 protein expression and cell cycle.Results： As2O3 could induced a G2/M cell cycle arrest.As2O3 ＋ irradiation could significantly decreased the proliferation rate（vs As2O3 group or irradiation group,P0.01）.As2O3 significantly decreased the expression of Bcl-2 in irradiated human lung cancer cell line A2（vs As2O3 group or irradiation group,P0.01）.Conclusion： Arsenic trioxide could sensitize the human lung cancer cell A2 to ionizing irradiation.This effect is probably caused by increasing the rate of G2/M cells before irradiation and the apoptosis rate of A2 cells after irradiation.