单唾液酸神经节苷脂3对人肺腺癌细胞增殖凋亡及血管内皮生长因子表达的影响

目的 研究外源性单唾液酸神经节苷脂3(GM3)对人肺腺癌细胞增殖、凋亡和血管内皮生长因子(VEGF)表达的影响,探讨GM3的抗肿瘤作用.方法 以不同浓度外源性GM3干预人肺腺癌A549细胞48 h,采用四甲基偶氮唑蓝(MTT)法检测细胞增殖变化,Annexin V-FITC/PI双染流式细胞学技术检测细胞凋亡变化,逆转录聚合酶链反应(RT-PCR)检测细胞VEGF mRNA的表达水平,激光共聚焦显微镜观察细胞VEGF蛋白的表达变化.结果 2.5、10、40、160和640 μmol/L GM3干预A549细胞48 h,增殖抑制率分别为4.1%、8.9%、29.9%、34.2%和52.6%,GM3作用于A549细胞48 h的半数抑制浓度(IC50)为412 μmol/L.与对照组相比,当GM3＞10 μmol/L时,对细胞增殖抑制作用明显(P＜0.05),且具有浓度依赖性.10、40和160μmol/L GM3干预A549细胞48 h,A549细胞的凋亡率分别为(1.3±0.6)%、(4.8±0.4)%、(14.2±1.0)%.与对照组相比,当GM3＞40 μmol/L时,其促进细胞凋亡作用明显(P＜0.05).与对照组相比,经浓度＞40 μmol/L的GM3干预后,A549细胞的VEGF mRNA表达水平显著下降(P＜0.05).随着GM3浓度增高,A549细胞的VEGF荧光强度明显减弱.结论 GM3能呈浓度依赖性抑制人肺腺癌细胞株A549增殖,促进A549细胞凋亡,下调A549细胞VEGF mRNA和蛋白水平的表达,提示GM3可能通过调节肿瘤细胞凋亡和肿瘤血管生成而发挥双重抗肿瘤作用.

Abstract：

Objective To determine the effect of exogenous GM3 on proliferation, apoptosis and VEGF expression in human lung adenocarcinoma cell line A549 cells.Methods A549 cells were treated with GM3 at different concentrations for 48 hours.MTT assay was used to detect the cell proliferation and flow cytometry was applied to analyze cell apoptosis.RT-PCR was used to detect the expression level of VEGF mRNA and confocal laser scanning microscopy was applied to observe the localization and fluorescence intensity of VEGF.Results Comparing with the control, being treated with higher than 10μmol/L GM3 significantly inhibited A549 cell proliferation ( P ＜ 0.05 ), and the suppressive effect could be enhanced following increasing doses.The IC50 was 412 μ mol/L.Comparing with the control, being treated with higher than 40 μmol/L GM3 significantly promoted the apoptotic rate of A549 cells ( P ＜ 0.05 ).Comparing with the control, being treated with higher than 40 μ mol/L GM3 significantly decreased the VEGF mRNA level of A549 cells (P＜0.05), and the fluorescence intensity of VEGF distinctly weakened.Conclusions Exogenous ganglioside GM3 can inhibit the proliferation, promote apoptosis, and down-regulate the VEGF expression level in A549 cells.This may be considered as two mechanisms of GM3 for its anti-tumor effect by modulating cell apoptosis and angiogenesis.

Effects of GM3 on proliferation, apoptosis and VEGF expression in human lung adenocarcinoma cell line A549 cells

Objective To determine the effect of exogenous GM3 on proliferation, apoptosis and VEGF expression in human lung adenocarcinoma cell line A549 cells.Methods A549 cells were treated with GM3 at different concentrations for 48 hours.MTT assay was used to detect the cell proliferation and flow cytometry was applied to analyze cell apoptosis.RT-PCR was used to detect the expression level of VEGF mRNA and confocal laser scanning microscopy was applied to observe the localization and fluorescence intensity of VEGF.Results Comparing with the control, being treated with higher than 10μmol/L GM3 significantly inhibited A549 cell proliferation ( P ＜ 0.05 ), and the suppressive effect could be enhanced following increasing doses.The IC50 was 412 μ mol/L.Comparing with the control, being treated with higher than 40 μmol/L GM3 significantly promoted the apoptotic rate of A549 cells ( P ＜ 0.05 ).Comparing with the control, being treated with higher than 40 μ mol/L GM3 significantly decreased the VEGF mRNA level of A549 cells (P＜0.05), and the fluorescence intensity of VEGF distinctly weakened.Conclusions Exogenous ganglioside GM3 can inhibit the proliferation, promote apoptosis, and down-regulate the VEGF expression level in A549 cells.This may be considered as two mechanisms of GM3 for its anti-tumor effect by modulating cell apoptosis and angiogenesis.