中文摘要：

目的：探讨维拉帕米逆转乳头状甲状腺癌对多柔比星抗性的L型钙离子通道/钙蛋白酶（L-Ca^2＋/calpain）信号转导通路机制。方法：以培养2 d的人乳头状甲状腺癌TPC-1细胞为实验对象,首先以CCK-8分析法测定细胞存活率对维拉帕米和多柔比星进行配伍试验,确定合适的药物作用浓度及时间。然后将细胞分为空白对照组、多柔比星组、维拉帕米组和多柔比星＋维拉帕米组。以全细胞膜片钳技术记录TPC-1细胞的L-Ca^2＋通道电流,以Western blot法测定蛋白calpain 1及LC3的表达水平。结果：多柔比星组、维拉帕米组与空白对照组相比,LCa^2＋通道电流密度减小（P〈0.05）;多柔比星＋维拉帕米组与多柔比星组相比,L-Ca^2＋通道电流密度减小（P〈0.01）。多柔比星组、维拉帕米组与空白对照组相比,calpain 1蛋白表达减弱（P〈0.05）;多柔比星＋维拉帕米组与多柔比星组相比,calpain 1蛋白表达减弱（P〈0.05）。多柔比星组和维拉帕米组与空白对照组相比,LC3蛋白表达增强（P〈0.05）;多柔比星＋维拉帕米组与多柔比星组相比,LC3蛋白表达增强（P〈0.01）。结论：TPC-1细胞抗多柔比星可能与其自噬活性增强有关;维拉帕米能进一步增强细胞自噬活性,致自噬性细胞死亡,从而对抗TPC-1细胞对多柔比星的抗性,其机制可能与自噬的L-Ca^2＋/calpain 1信号转导通路有关。

英文摘要：

AIM：To investigate the mechanism of L-type calcium channel （ L-Ca^2＋）/calpain signal transduction pathway in verapamil inversing resistance of papillary thyroid carcinoma to doxorubicin .METHODS：Human papillary thyroid carcinoma TPC-1 cells were cultured for 2 d.For determining the appropriate concentrations and treatment time of verapamil and doxorubicin , a compatibility test was conducted to detect the cell viability by CCK-8 assay.The cells were divided into control group , doxorubicin group , verapamil group and doxorubicin ＋verapamil group .The techniques of whole-cell patch-clamp was used to record L-Ca^2＋currents.The protein expression levels of calpain 1 and LC3 were detected by Western blot .RESULTS： Compared with control group , the density of L-Ca^2＋current decreased in doxorubicin group and verapamil group （P〈0.05）.Compared with verapamil group , the density of L-Ca^2＋current decreased in doxo-rubicin＋verapamil group （P〈0.01）.Compared with control group, the expression of calpain 1 decreased in doxorubicin group and verapamil group （P〈0.05）.Compared with doxorubicin group , the expression of calpain 1 decreased in doxo-rubicin＋verapamil group （P〈0.05）.Compared with control group , the expression of LC3 increased in doxorubicin group and verapamil group （P〈0.05）.Compared with doxorubicin group , the expression of LC3 increased in doxorubicin ＋verapamil group （ P〈0.01） .CONCLUSION：The drug resistance of TPC-1 cells to doxorubicin may be related to the increase in autophagic activity .Verapamil further increases autophagic activity of TPC-1 cells, resulting in autophagic death and inversing the resistance of TPC-1 cells to doxorubicin .The mechanism may be involved in L-Ca^2＋/calpain 1 signal transduction pathway of autophagy .