氨基末端激酶参与胃癌顺铂耐药机制的研究

目的 研究氨基末端激酶(p-JNK)参与胃癌SGC7901/DDP细胞株顺铂耐药的机制.方法 应用JNK通路抑制剂SP600125抑制p-JNK表达,通过四氮唑盐还原法(MTF)检测药物敏感性;流式细胞术分析细胞凋亡率;Western印迹检测p-JNK和耐药蛋白P-糖蛋白(Pglycoprotein,P-gp)在敏感株SGC7901和耐药株SGC7901/DDP中的表达变化.免疫组织化学方法检测含有168例胃癌和27例正常胃的组织芯片中p-JNK和P-gp的表达及分析其关系.结果 SP600125抑制p-JNK表达后,敏感株SGC7901和耐药株SGC7901/DDP的药物敏感性和细胞凋亡率增加(P＜0.01);耐药蛋白P-gP表达水平明显减低(0.21±0.01和0.77±0.05比0.06±0.01和0.52±0.06:P＜0.01).p-JNK和P-gp在胃癌组织中的表达分别为45.8%和51.8%,均显著高于正常胃组织中的7.4%和18.5%(P＜0.01).p-JNK和P-gp的表达呈正相关(P＜0.01).结论 p-JNK通过调节P-gp表达及抗凋亡信号通路参与胃癌顺铂耐药,可成为逆转耐药的新的靶点.

Study on the mechanism of DDP-resistance mediated by phosphate JNK in gastric cancer

OBJECTIVE: To investigate the mechanism of DDP-resistance in gastric cancer cell line SGC7901/DDP mediated by phosphate(p)-JNK. METHODS: The p-JNK expression was blocked by the JNK inhibitor SP600125. The drug sensitivity was detected by MTT. Cell apoptosis rate was measured by flow cytometry. The expression of p-JNK and P-glycoprotein (P-gp) was examined by Western blot. The expression of both proteins were detected in a tissue microarray containing 168 spots of cancer tissue and 27 spots of normal gastric tissue by SP immunohistochemistry. Pearson method was used to analyze the correlation between p-JNK and P-gp. RESULTS: The drug sensitivity and cell apoptosis rate significantly increased (P<0.01), and the protein expression levels of p-JNK and P-glycoprotein were down-regulated after the inhibition of p-JNK by SP600125 in both SGC7901(p-JNK: 1.17+/-0.03 vs 0.38+/-0.071, P-gp: 0.21+/-0.01 vs 0.06+/-0.01) and SGC7901/DDP (p-JNK: 2.56+/-0.14 vs 1.02+/-0.12, P-gp: 0.77+/-0.05 vs 0.52+/-0.06 )cells(all P<0.01). The protein expression rates of p-JNK and P-glycoprotein were 45.8% and 51.8% respectively in gastric cancer tissue, which were significantly higher than those in normal gastric tissue 7.4% and 18.5% (P<0.01). The correlation of protein expression of p-JNK and P-gp was positive (P<0.01). CONCLUSION: JNK anti-apoptosis pathway with the regulation of P-gp expression plays an important role in the DDP-resistance of gastric cancer, which may be a novel target for reversing multidrug resistance.