热疗对胃癌细胞株化疗敏感性的影响

目的:探讨热疗时胃癌细胞株对紫杉醇(paclitaxel,TAX)敏感性的变化。方法:用对TAX敏感的胃癌细胞株MKN-45经浓度梯度递增法建立胃癌TAX耐药细胞株,命名为MKN-45/TAX。采用免疫细胞化学染色法检测MKN-45/TAX和MKN-45细胞中多药耐药相关基因(multi-drug resistance gene,MDR1)的表达;采用CCK-8法检测不同温度和不同TAX浓度作用下2种细胞的增殖抑制率;采用实时荧光定量–聚合酶链反应(real-time polymerase chain reaction,RT-PCR)法、蛋白质印迹(Western blotting)法检测经靶向siRNA处理前后MDR1 mRNA和P糖蛋白(P-glycoprotein,P-gp)的表达。结果:成功建立MKN-45/TAX。MDR1在MKN-45/TAX中高表达而在MKN-45中低表达。随着紫杉醇浓度的增加,其对MKN-45及MKN-45/TAX的增殖抑制率增加;42℃时紫杉醇对MKN-45/TAX的增殖抑制率降低,而对MKN-45的增殖抑制率则升高。转染MDR1 siRNA后MDR1 mRNA和P-gp的表达水平均下降。结论:热疗联合化疗可增强耐药胃癌细胞株对TAX的耐药性,而增强敏感胃癌细胞株对TAX的敏感性,其机制可能与MDR1表达有关。

Effects of Hyperthermia on the Sensitivity of Gastric Cancer Cell Lines to Chemotherapy

Objective：To observe the effects of hyperthermia on the sensitivity of gastric cancer cell lines to paclitaxel （TAX） . Methods ：To establish TAX-resistant gastric cancer cell line through a method of increasing concertration gradient and named it MKN-45/TAX Immunocytohistochemistry staining method was used to detect the expression of multi-drug resistance gene （MDR1） in MKN-45/TAX and MKN-45 .CCK-8 test was used to detect the proliferation inhibition rates in two kinds of cell lines under different temperatures and different TAX concentration .Real-time polymerase chain reaction （RT-PCR） and West-ern blotting were used to detect the expression of MDR1 mRNA and P-glycoprotein （P-gp） before and after target siRNA treat-ment .Results：Establishment of MKN-45/TAX cell line was successful .The expression level of MDR1 was high in MKN-45/TAX whereas it was low in MKN-45 .As TAX concentration increased ,the proliferation inhibition rates of both cell lines in-creased .At 42 ℃ the proliferation inhibition rate of MKN-45/TAX to TAX chemotherapy decreased ,while that of MKN-45 was the opposite .Both the expression of MDR1 mRNA and P-gp decreased after the siRNA transfection .Conclusions ：Hyper-thermia combined with chemotherapy may enhance the resistance of TAX-resistant gastric cancer cell line to TAX ,while it may enhance the sensitivity of TAX-sensitive gastric cancer cell line to TAX .The mechanism may be related to the expression of MDR1 .