【摘要】 目的探讨Smad4基因沉默对奥沙利铂(OXA)抑制乳腺癌细胞MDA-MB-231侵袭迁移能力的影响及其作用机制。方法采用MTT法检测不同浓度OXA(0,0.25,0.5,1,2,4μmol/L)对MDA-MB-231细胞的增殖抑制作用;Smad4 siRNA转染MDA-MB-231细胞株,并用Western blot检测转染后Smad4蛋白表达;Transwell小室法和细胞划痕实验检测MDA-MB-231细胞侵袭迁移活性;Western blot和ELISA检测细胞中TGF-β和MMP-9蛋白表达和活性的变化。结果 1μmol/L OXA作用于MDA-MB-231细胞24,48,72 h细胞存活率分别是(77.42±3.98)%,(60.38±3.65)%和(40.15±4.37)%。siRNA转染后MDA-MB-231细胞中Smad4的表达明显被抑制(P<0.05);Smad4 siRNA转染可增强OXA抑制MDA-MB-231细胞的侵袭和迁移活性(P<0.05);Smad4 siRNA转染使OXA下调细胞中TGF-β和MMP-9蛋白表达和活性明显增强(P<0.05)。结论下调Smad4的表达可以增强OXA抑制乳腺癌MDA-MB-231细胞侵袭迁移的活性,其机制可能与影响TGF-β/Smad4通路并下调MMP-9表达有关。更多还原

【Abstract】 Objective To investigate the effect of small interfering RNA-mediated Smad4 knockdown on oxaliplatin( OXA) inhibiting the invasion and migration of breast cancer cell MDA-MB-231 and to explore its mechanism. Methods The viability of MDA-MB-231 cells exposed to different concentrations( 0,0. 25,0. 5,1,2 and 4 μmol / L) of OXA were detected by MTT assay. Western blot was used to detect Smad4 expression in MDA-MB-231 cells transfected with Smad4 siRNA. Transwell small chamber assay and wound healing assay were used to examine the invasion and migration of MDA-MB-231 cells. TGF-β and MMP-9 expression levels and activities were determined using Western blot and ELISA assay. Results The survival rates of MDA-MB-231 cell were 77. 42%,60. 38% and40. 15% after exposed to OXA( 1 μmol / L) for 24,48 and 72 h,respectively. The expression level of Smad4 in MDA-MB-231 cells was significantly inhibited after Smad4 siRNA transfection. Smad4 siRNA transfection enhanced the inhibition of OXA on the MDAMB-231 invasive and metastasic activities( P < 0. 05). Smad4 siRNA transfection enhanced the down-regulation of expression of TGF-β and MMP-9 in MDA-MB-231 cells by OXA( P < 0. 05). Conclusion Smad4 siRNA transfection can enhance the inhibitory effect of OXA on the invasion and migration of MDA-MB-231 cells,which may be related to the regulation via TGF-β / Smad4 pathway and the down-regulation of MMP-9.更多还原