血红素氧合酶-1对人胃癌SGC7901细胞5-氟尿嘧啶化疗敏感性的影响

Influence of heme oxygenase-1 on the sensitivity of human gastric cancer cell line SGC7901 to 5-FU in vitro

目的:体外观察血红素氧合酶-1(heme oxygenase-1,HO-1)对人胃癌细胞SGC79015-氟尿嘧啶(5-FU)化疗敏感性的影响及其可能的机制。方法:应用不同浓度锌原卟啉(ZnPP)、氯化血红素(Hemin)单独或联合5-FU作用于人胃癌SGC7901细胞不同时间,四甲基偶氮唑盐(MTT)法观察药物对细胞生长抑制作用;Western blot分析细胞HO-1蛋白表达变化;流式细胞术检测细胞凋亡率;活性氧(ROS)检测试剂盒分析其凋亡机制。结果:ZnPP和5-FU均可明显抑制人胃癌SGC7901细胞生长,呈剂量依赖性;5-FU联用ZnPP(10μmol/L)与单用药相比,明显提高了细胞生长抑制率和凋亡率(P<0.05),联用Hemin(10μmol/L)则明显降低细胞生长抑制率和凋亡率(P<0.05);人胃癌SGC7901细胞中可见HO-1表达,单用5-FU或Hemin后均能使其表达增强,联用ZnPP可逆转此现象;单用5-FU与对照组比较,细胞内ROS活性明显增高,联用后ZnPP可进一步提高细胞内ROS活性(P<0.05),而联用Hemin明显降低细胞内ROS活性水平(P<0.05)。结论:ZnPP抑制HO-1表达,能够增强人胃癌SGC7901细胞对5-FU化疗敏感性,这一作用可能与增加细胞内ROS活性有关。

Objective：To study the potential effects of heme oxygenase-1（HO-1）on the sensitivity of human gastric cancer cell line SGC7901 to 5-FU in vitro and the possible mechanisms involved.Methods：All cells were treated with various concentrations of hemin,ZnPP and 5-FU combination or alone at different times.The inhibition rate of cells was evaluated by MTT assay.Western blot was used for the detection of HO-1 expression.Flow cytometry was performed to detect cell apoptosis.ROS activity was examined by ROS colorimetric assay.Results：The application of ZnPP or 5-FU significantly inhibited the proliferation of human gastric cancer cells and the effect was dose-dependent.ZnPP（10 μmol/L）combined with 5-FU led to more inhibition and cell apoptosis than ZnPP or 5-FU alone（P0.05）.On the other hand,hemin（10 μmol/L）markedly increased the resistance of SGC7901 cells to 5-FU-mediated cytotoxicity（P0.05）.5-FU or hemin increased HO-1 protein expression compared with control group,and the increase was reversed by the use of ZnPP.The activity of ROS in 5-FU plus ZnPP group had a significant increase compared with other groups（P0.05）,and the increase was reversed by the addition of hemin.Conclusion：ZnPP can enhance the chemosensitivity of SGC7901 cells to 5-FU,in which the inhibition of HO-1 expression and elevation of intracellular ROS activity may be involved.