塞来昔布对肺癌细胞的增殖抑制、环氧化酶-2表达的影响和化疗敏感性

Effects of cyclooxygenase-2 inhibitor celecoxib on cyclooxygenase-2 gene expression and cisplatin chemosensitivity in human lung adenocarcinoma A549 cell line

目的:探讨环氧化酶(COX)-2抑制剂塞来昔布(celecoxib)对肺癌A549细胞的增殖抑制、COX-2表达和化疗敏感性的影响。方法:用四甲基偶氮唑盐微量酶反应比色法(MTT法)检测塞来昔布单药及联合顺铂(DDP)对COX-2高表达的人肺腺癌细胞A549的增殖抑制,流式细胞术分析塞来昔布联合DDP对细胞周期及细胞凋亡的影响,Westernblot法分析不同浓度塞来昔布干预后对A549细胞内COX-2蛋白表达的影响。结果:MTT法检测显示,塞来昔布(0～100μmol/L)对肺腺癌A549细胞的抑制作用呈时间依赖性、剂量依赖性效应,联合用药组与单药组相比差异有显著性(P<0.001)。流式细胞术分析显示,塞来昔布12.5μmol/L与25μmol/L联合DDP0.5mg/L时,A549细胞明显阻滞于G0-G1期,S期细胞比例减少,联合用药组的凋亡率明显高于单药组(P<0.001)。Westernblot法分析显示,塞来昔布浓度超过50μmol/L时,COX-2蛋白的表达受到了抑制。结论:塞来昔布的抗肿瘤作用机制涉及到COX-2依赖性途径。塞来昔布能增加DDP的化疗敏感性,塞来昔布与DDP联用对人肺腺癌A549细胞有明显协同抗肿瘤效应,该作用可能是通过增强对A549细胞的增殖抑制、诱导凋亡来实现的。

Objective： To evaluate the effects of cyclooxygenase （COX）-2 inhibitor celecoxib on COX-2 gene expression and cisplatin chemosensitivity in human lung adenocarcinoma A549 cell line with overexpressed COX-2. Methods： The inhibitory effects of celecoxib or celecoxib combined with anticancer drug cisplatin on the proliferation of human lung adenocarcinotha 3,549 cell line were detected by MTr. The cell growth inhibition and cell cycle apoptosis were assessed by MIT and flow cytometry. COX-2 gene expression was detected by Western blot. Results： There was a dose-dependent and time-dependent（0-100μmol/L）inhibition of cell proliferation induced by celecoxib. IC50 value of celecoxib in A549 was 30.9μmol/L 72 hours after the treatment. The cell growth inhihition rate of A549 was（14.17 ± 1.39）%, （19.11 ± 1.45）% and （38.16 ± 1.67）% in cisplatin（0.5 mg/L）group and celecoxib groups （12.5μmol/L, 25 μmol/L） respectively. When combined treatment of celecoxib （12.5 μmol/L, 25 μmol/L） and cisplatin （0.5 mg/L）was used, the cell growth inhibition rate was （33.75± 2.02）% and （49.64 ± 2.19）%, respectively. The differences were significant （P 〈 0. 001 ）. The apoptotic rate of A549 cells induced by cisplatin（0.5 mg/L）or celecoxib（12.5 μmol/L, 25μmol/L） was（ 1.74±0.77）%, （0.26 ± 0.02）% or （2.75 ±0.13）%, respectively. The apoptotic rate was （6.49 ± 0.88）% and （10.59 ± 1.22）% after combined treatment of celecoxib （12.5 μmol/L, 25μmol/L） and cisplatin（0.5 mg/L） respectively. High-dose celecoxib （〉50μmol/L） can suppress COX-2 gene expression. Conclusion： The anticancer effects of a selective COX-2 inhibitor celecoxib partly depend on COX-2 expression in the cells. Combined treatment with celecoxib plus cisplatin shows significantly greater inhibitory effects on the growth of human lung adenocarcinoma A549 cell line.