新生霉素衍生物FM-NOV17抑制Her2+乳腺癌细胞的作用及其机制

目的研究新生霉素衍生物FM-NOV17对乳腺癌Skbr3细胞的作用,并探讨该作用是否与其干扰热休克蛋白90(Hsp90)分子伴侣的功能从而促进Her2降解有关。方法用蛋白免疫印迹法检测Her2的含量,采用免疫共沉淀的方法研究FM-NOV17对乳腺癌细胞Hsp90分子伴侣功能的影响。用免疫共沉淀的方法将Her2与其分子伴侣复合物沉淀下来,用免疫印迹法检测沉淀物中与Her2结合的Hsp90和辅伴侣Hsp70含量的变化。结果 FM-NOV17能降低乳腺癌细胞Skbr3中Her2的蛋白水平,FM-NOV17使Her2与Hsp90和Hsp70的结合减少,降低Her2蛋白水平,诱导细胞周期阻滞和凋亡。结论 FM-NOV17通过干扰Hsp90伴侣功能,减少Her2与Hsp90和辅伴侣的结合,降低Her2蛋白量,最终抑制乳腺癌细胞增殖。

Effects of FM-NOV17 on Her2+ Breast Cancer Cells And its Mechanisim

ObjectiveTo confirm the effects of FM NOV17, one of novobiocin derivatives, on breast cancer cells (Skbr3), and to study the relationship between these effects and the molecular chaperone functions of heat shock protein 90 (Hsp90).MethodsThe quantity of Her2 protein was determined by Western blot.Molecular chaperone functions of Hsp90 on breast cancer cells were measured by coimmunoprecipitation.After the co immunoprecipitation of Her2 and its molecular chaperones, the immunoprecipitate was then subjected to Western blot analysis with anti Her2 to study changes in quantity of anti Hsp90, or anti Hsp70 mAb.ResultsAn exposure of Skbr3 cells to FM NOV17 led to down regulation of intracellular Her2 protein levels.FM NOV17 treatment also decreased the binding of Her2 with Hsp90 and Hsp70.Consequently, apoptosis and cell cycle arrest were induced.ConclusionsThese studies demonstrate that the activities of FM NOV17 might inhibit breast cancer cells through the disruption of Hsp90 chaperon function, which results in disruption of the binding of Her2 to Hsp90 and cochaperons and the level of Her2 protein.That may be an important mechanism, by which FM NOV17 mediates its effects on breast cancer cells.