PARP抑制剂Olaparib对非小细胞肺癌细胞的放疗增敏作用及其机制

The Radiosensitizing Effect of PARP Inhibitor Olaparib on Non-small Cell Lung Cancer Cells and Its Possible Mechanism

目的探讨聚腺苷二磷酸核糖聚合酶(PARP)抑制剂Olaparib对人非小细胞肺癌(NSCLC)细胞的放疗增敏作用及其可能的发生机制。方法以人NSCLC细胞A549细胞系为研究对象,采用CCK-8实验检测不同药物浓度梯度对细胞的增殖抑制作用。选择对细胞10%抑制浓度(IC10)作为后续实验的药物浓度,实验分为对照组、Olaparib组、单纯放疗组(RT组)、Olaparib联合放疗组(Olaparib+RT组)。通过克隆形成实验和EDU细胞增殖实验检测Olaparib联合放疗后的增敏效果,流式细胞术检测各组细胞周期分布,Western blot实验检测各组DNA损伤标志蛋白γ-H2AX的表达。结果Olaparib对A549细胞具有抑制作用且呈剂量依赖性;在处理A549细胞24 h后IC10为2.593μmol·L^(-1);Olaparib放疗增敏比为1.966。Olaparib+RT组A549细胞的增殖能力下降(P<0.01);Olaparib+RT组的G2/M期细胞占比高于对照组(46.0%vs 10.8%,P<0.05);且Olaparib+RT组细胞中γ-H2AX明显高于RT组(P<0.01)。结论Olaparib对人NSCLC细胞A549细胞系有着放疗增敏效果,其机制可能与影响细胞周期、增加放疗后细胞DNA双链断裂形成相关。

Objective To investigate the radiosensitizing effect of Olaparib,a poly(ADPribose)polymerase(PARP)inhibitor,on human non-small cell lung cancer(NSCLC)cells and its possible mechanism.Methods The A549 cell line as human NSCLC cell was used as the research object,and the CCK-8 assay was used to detect the proliferation inhibition effect of different drug concentration gradients on the cells.With the 10%inhibitory concentration(IC10)for cells established as the drug concentration,the subsequent experiments were divided into the control group,Olaparib group,radiotherapy-only group(RT group),and Olaparib combined with radiotherapy group(Olaparib+RT group).The sensitizing effect of Olaparib combined with radiotherapy was confirmed by clone formation assay and EDU cell proliferation assay;the cell cycle distribution of different treatment groups was detected by flow cytometry;the expression of the DNA damage marker proteinγ-H2AX was detected by Western blot assay in each group.Results Olaparib had an inhibitory effect on A549 cells in a dose-dependent manner;the IC10 was 2.593μmol·L^(-1) after Olaparib treatment of A549 cells for 24 h;the Olaparib radiosensitization ratio was 1.966;the proliferative ability of A549 cells in Olaparib+RT group was decreased(P<0.01);the percentage of cells in G2/M phase in Olaparib+RT group was higher than that in the control group(46.0%vs 10.8%,P<0.05);γ-H2AX in the cells of the Olaparib+RT group was significantly higher than that of the RT group(P<0.01).Conclusion The results of this study suggest that Olaparib can produce radiosensitizing effects on A549 cells,and its mechanism may be related to the formation of cellular DNA double-strand breaks after increased radiotherapy which can affect the cell cycle.