热疗联合5-氟尿嘧啶对胃癌MKN45细胞抑制作用机制研究

The inhibitive effect of gastric carcinoma cell line MKN45 with hyperthermia and 5-Fu in vitro

目的:探讨5-氟尿嘧啶(5-Fu)温热化疗对人低分化胃癌细胞(MKN45细胞)抑制的分子作用机制。方法:以MTT法测定MKN45细胞48h的IC50作为实验工作浓度,实验分对照组(C)、热疗组(H)、化疗组(D)、热化疗组(HD),检测细胞抑制率;应用逆转录-聚合酶链反应(RTPCR)观察表皮生长因子受体EGFR与原癌基因RAS mRNA的表达变化。结果:热、化疗均可抑制MKN45细胞系(P<0.05),热化疗抑制作用更明显(P<0.05);RT-PCR分析显示,热化疗组EGFRmRNA与RASmRNA表达下调最明显(P<0.05)。EGFR mRNA与RAS mRNA的表达呈明显的正相关性(r=0.870,P<0.05),细胞抑制率与EGFRmRNA表达水平间存在负相关关系(r=-0.956,P<0.05),细胞抑制率与RASmRNA表达水平间存在负相关关系(r=-0.923,P<0.05)。结论:化疗联合热疗能显著增加对MKN45细胞的体外抑制作用,其机制可能与下调EGFR与RAS的表达及二者相互作用有关。

Objective ： To observe the inhibitive effect of MKN45 cells with 5-Fu and hyperthermia,and dis-cusses its mechanism. Methods ： MTT assay determine the inhibiting concentration 50%（IC50）at 48 hours as its working concentration. The cells were divided into control、 chemotherapy、 hyperthermia and hyperthermia combined with chemotherapy groups. The EGFR mRNA and RAS mRNA were determined by RT-PCR . Results： 5-Futher- mo-chemotherapy showed the most obvious inhibition to MKN45 cells（P〈0. 05）. A positive response correlation could be found between the expression of EGFR mRNA and RAS mRNA（r=0. 870）. There was negative response correlation between the inhibitive effect and the expression of EGFR mRNA （r= -0. 956, n=12） . There was neg-ative response correlation between the inhibitive effect and the expression of RAS mRNA（r= - 0. 923, n= 12）. Conclusion： 5-Furubicin combined with hypothermia shows obvious inhibitive effect to MKN45 cells , increases the inhibition,possibly through down-regulation of EGFR and RAS .