JNK信号通路介导ghrelin对乳腺癌MDA-MB-231细胞耐药蛋白表达的影响

目的探讨ghrelin调控c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)信号转导通路对乳腺癌细胞P-糖蛋白表达的影响。方法培养人乳腺癌MDA-MB-231细胞,分别加入生长激素释放肽(ghrelin,100 nmol/L,干预72小时)、多柔比星(0.8 mg/L,干预72小时)、ghrelin联合多柔比星(ghrelin 100 nmol/L,多柔比星0.8 mg/L,干预72小时)。采用MTT方法检测细胞增殖,Western blot法检测细胞JNK、P-糖蛋白(P-glycoprotein,P-gp)的表达及p-JNK水平。结果 MTT检测显示,人乳腺癌MDA-MB-231细胞在ghrelin的干预下增殖(P<0.01),存活率在多柔比星的干预下降低(P<0.01),ghrelin联合多柔比星能够抑制多柔比星对MDA-MB-231细胞的杀伤作用(P<0.01)。ghrelin组JNK表达及p-JNK水平上升(均P<0.01),且P-gp蛋白表达上升(P<0.05);多柔比星组JNK表达及p-JNK水平下降(均P<0.01);ghrelin联合多柔比星较多柔比星组JNK表达及p-JNK水平增加,且P-gp表达明显上升(均P<0.05)。结论 ghrelin激活JNK信号通路干预乳腺癌细胞P-gp表达增加从而抑制多柔比星诱导乳腺癌细胞凋亡。

Ghrelin enhances expression of P-glycoprotein in breast cancer MDA-MB-231 cells through JNK signaling pathway

Objective: To investigate the effect of ghrelin on the expression of P-glycoprotein (P-gp) in breast cancer cells and its mechanism. Methods: Human breast cancer MDA-MB-231 cells were cultured with 100 nmol/L ghrelin for 72 h, 0.8 mg/L doxorubicin for 72 h or 100 nmol/L ghrelin combined with 0.8 mg/L doxorubicin for 72 h, respectively. MTT method was used to detect cell proliferation. The protein levels of JNK, P-gp and p-JNK were analyzed by Western blot. Results: MTT assay showed that the proliferation of MDA-MB-231 cells was increased with ghrelin treatment (P<0.01); the cell survival rate was significantly decreased after doxorubicin treatment (P<0.01). Ghrelin combined with doxorubicin inhibited the effect of doxorubicin on MDA-MB-231 cells (P<0.01). The expression of JNK and p-JNK in ghrelin treated cells was increased significantly (P<0.01), while that in doxorubicin treated cells was decreased (P<0.01). In cells treated with both ghrelin and doxorubicin, the expression of JNK and p-JNK was higher than that in doxorubicin group, and P-gp expression was also significantly increased (P<0.05). Conclusion: Ghrelin activates JNK signaling pathway to induce the expression of P-gp in breast cancer cells, which subsequently inhibits doxorubicin mediated apoptosis of breast cancer cells. © 2016, Editorial Board of Journal of Practical Oncology. All right reserved.