耐阿霉素人乳腺癌细胞MCF-7/ADM钙稳态失调及其机制研究

Study on calcium homeostasis disorders of adriamycin resistant human breast cancer cells MCF-7/ADM and its mechanism

目的探讨耐阿霉素人乳腺癌细胞MCF-7/ADM钙稳态失调及其机制。方法转染指示钙离子质粒GECO1.2,检测野生型和耐药型细胞中的[Ca2+]含量;通过Westernblot检测瞬时受体电位离子通道(transient receptor potentialchannel)蛋白TRPC1、TRPC3、TRPC4、TRPC5和TRPC6在两种细胞中的表达情况;运用钙离子通道抑制剂2-APB(100μmol.L-1)抑制耐药细胞中高表达的TRPC5活性后,检测耐药细胞中的[Ca2+]含量。结果耐药细胞中的[Ca2+]含量明显上调,并检测到TRPC5蛋白在耐药细胞中发生高表达,其活性被抑制后,耐药细胞中的[Ca2+]浓度发生下调。结论与野生型细胞相比,耐药细胞中钙稳态失调,其原因可能是由于耐药细胞中TRPC5表达上调引起耐药细胞中[Ca2+]内流所致。提示钙稳态失调与肿瘤细胞的耐药发生有着密切关系。

Aim To investigate the calcium homeosta- sis disorders of adriamycin-resistant human breast cancer cells MCF-7/ADM and its mechanism. Meth- ods Detect the （[ Ca2＋ ]） content of wild-type and drug-resistant cells by the transformation of calcium in- dicator plasmid GECO1.2; Detect the expression of transient receptor potential ion channel protein TRPC1, TRPC3, TRPC4, TRPC5 and TRPC6 in these two cells by Western blot; Suppress the TRPC5 activity with cal- cium channel inhibitor 2-APB （ 100μmol .L-1 ） , and then detect the （ [ Ca2＋ ] ） content in the drug-resistant cells. Results The result shows that the significantly up-regulation of （ [ Ca2＋ ] ） content in resistant cells,and the TRPC5 protein shows over-expression, but the （ [ Ca2＋ ] ） concentration became to decrease after the inhibition of its activity. Conclusion Compared with the wild-type cells, the calcium in resistant cells be- came homeostasis disorder, maybe the underlying mechanism is the up-regulation of TRPC5 caused [ Ca2＋] entry into the resistant cells. This study sug- gests that there must be a close relationship between calcium homeostasis disorders and the drug resistance of cancer.