mTOR激酶抑制剂CC-223抑制乳腺癌细胞增殖的实验研究

目的:探讨哺乳动物雷帕霉素靶蛋白(mTOR)激酶抑制剂CC-223对乳腺癌细胞增殖的抑制作用及其相关分子机制。方法:CCK-8法检测CC-223对人乳腺癌细胞MCF-7和MDA-MB-231细胞活力的抑制作用;流式细胞术分析CC-223对乳腺癌细胞周期的影响;Western blot实验检测CC-223对细胞周期调控相关蛋白及细胞增殖相关蛋白c-Myc和存活蛋白(survivin)表达的影响。结果:CCK-8结果表明,CC-223能够显著抑制MCF-7细胞和MDA-MB-231细胞活力(P<0.05);流式细胞术实验结果显示,CC-223能够诱导MCF-7细胞发生G 1期和G 2/M期阻滞(P<0.05);较低浓度的CC-223诱导MDA-MB-231细胞周期阻滞于G 2/M期(P<0.05),而处于G 1期的细胞数量无显著差异。CC-223处理乳腺癌细胞24 h后,细胞周期蛋白B1、细胞周期蛋白D1表达和细胞分裂周期蛋白2(Cdc2)磷酸化水平显著降低(P<0.05)。Western blot结果表明,MCF-7和MDA-MB-231细胞经CC-223作用后,c-Myc和survivin的表达水平显著下调(P<0.05)。结论:CC-223能够抑制乳腺癌细胞活力,阻滞细胞周期进程,同时下调乳腺癌细胞中c-Myc与survivin的蛋白表达。

mTOR kinase inhibitor CC-223 suppresses human breast cancer cell viability

AIM:To investigate the inhibitory effect of CC-223,an inhibitor of mammalian target of rapamycin(mTOR)kinase,on the viability of human breast cancer cells and its mechanism.METHODS:The inhibitory effect of CC-223 on the viability of MCF-7 cells and MDA-MB-231 cells was measured by CCK-8 assay.The cell cycle distribution of breast cancer cells was examined by flow cytometry.The expression of cell cycle-related proteins and oncoproteins c-Myc and survivin was analyzed by Western blot.RESULTS:CC-223 significantly inhibited the viability of both MCF-7 and MDA-MB-231 cells(P<0.05).CC-223 induced cell cycle arrest in both G1 phase and G2/M phase in the MCF-7 cells(P<0.05).However,low concentration of CC-223 treatment resulted in the accumulation of MDA-MB-231 cell cycle in the G2/M phase,and the cell number in G1 phase was unaffected.Treatment with CC-223 for 24 h clearly inhibited the protein levels of cyclin B1,cyclin D1 and phosphorylated cell division cycle protein 2 in the breast cancer cells(P<0.05).CC-223 suppressed the expression of c-Myc and survivin in both MCF-7 cells and MDA-MB-231 cells(P<0.05).CONCLUSION:CC-223 inhibits cell viability by blocking cell cycle progression and down-regulating expression of c-Myc and survivin in both MCF-7 and MDA-MB-231 cells.