健脾解毒方通过抑制环氧化酶2下调幽门螺杆菌诱导的人胃癌细胞血管内皮生长因子表达

Chinese herbal medicine Jianpi Jiedu Formula down-regulates the expression of vascular endothelial growth factor in human gastric cell line MKN45 induced by Helicobacter pylori by inhibiting cyclooxygenase-2

目的:探讨健脾解毒方对幽门螺杆菌(Helicobacter pylori,Hp)感染胃癌细胞诱导的血管内皮生长因子(vascular endothelial growth factor,VEGF)表达的调控作用及可能的机制。方法:采用Hp标准株NCTC11637与人胃癌MKN45细胞共培养的方法感染MKN45细胞,实验中共分7组:对照组、Hp感染组、NS398抑制组、空白血清组和5%、10%、20%健脾解毒方药物血清组。采用实时荧光定量聚合酶链式反应法检测Hp感染对人胃癌MKN45细胞VEGF和环氧化酶2(cyclooxygenase-2,COX-2)mRNA表达的影响及健脾解毒方血清对Hp感染诱导的人胃癌MKN45细胞VEGF和COX-2mRNA表达的影响;采用COX-2特异性抑制剂NS398(50μmol/L)抑制COX-2的表达后,检测Hp感染后人胃癌MKN45细胞VEGF mRNA表达的变化。结果:与对照组比较,Hp感染MKN45细胞6h后,Hp感染组COX-2mRNA的表达明显上调(P<0.01);感染12h后,VEGF mRNA表达亦明显上调(P<0.01);而采用COX-2特异性抑制剂NS398抑制COX-2表达后,Hp感染组VEGF mRNA的表达相比抑制前明显下调(P<0.01)。与Hp感染组比较,5%、10%和20%健脾解毒方药物血清均可下调Hp诱导的人胃癌MKN45细胞VEGF和COX-2mRNA的表达,并呈一定的剂量依赖效应。结论:Hp感染可诱导人胃癌细胞VEGF和COX-2表达,健脾解毒方通过下调COX-2表达进而下调VEGF的表达,这可能是其防治胃癌的重要作用机制之一。

Objective：To investigate the effects of Jianpi Jiedu Formula （JPJDF）,a compound Chinese herbal medicine,on vascular endothelial growth factor （VEGF） expression induced by Helicobacter pylori （Hp） in human gastric cancer cells,and to explore the possible mechanism.Methods：Human gastric MKN45 cancer cells were infected with standard Hp NCTC11637 by coculture,and the cells were divided into 7 groups：normal control group,Hp group,NS398 inhibitor group,blank serum group,and 5%,10% and 20% JPJDF groups.The expressions of VEGF and cyclooxygenase-2 （COX-2） mRNAs in human gastric cancer cells infected by Hp were evaluated by real-time fluorogenic quantitative polymerase chain reaction （PCR）.After inhibiting the expression of COX-2 with COX-2 specific inhibitor NS398 （50 μmol/L）,VEGF mRNA expression induced by Hp in human gastric cancer MKN45 cells was evaluated by real-time fluorogenic quantitative PCR.Results：Real-time fluorogenic quantitative PCR results showed that COX-2 mRNA expression increased significantly after MKN45 cells were infected with Hp for 6 h （P0.01）,and VEGF mRNA expression also increased significantly after MKN45 cells were infected with Hp for 12 h as compared with the normal control group （P0.01）.After inhibiting COX-2 expression with COX-2 specific inhibitor NS398,Hp-induced VEGF mRNA expression significantly reduced （P0.01）.5%,10% and 20% JPJDF-containing sera all down-regulated VEGF and COX-2 mRNA expressions induced by Hp in a dose-dependent manner as compared with the Hp infection group.Conclusion：Hp could induce the expressions of COX-2 and VEGF in human gastric cancer cells,and JPJDF down-regulates Hp-induced expression of VEGF by inhibiting COX-2,which might be one of the important mechanisms of its prevention and treatment of gastric cancer.