Smad3 Is a Key Nonredundant Mediator of Transforming Growth Factor β Signaling in Nme Mouse Mammary Epithelial Cells
Smad3 Is a Key Nonredundant Mediator of Transforming Growth Factor β Signaling in Nme Mouse Mammary Epithelial Cells
复制标题
DOI：
10.1158/1541-7786.mcr-08-0558
复制
发表时间：
2009-08-01
影响因子：
5.2
通讯作者：
Verschueren, Kristin
中科院分区：
文献类型：
--
作者：
Dzwonek, Joanna;Preobrazhenska, Olena;Verschueren, Kristin
Smad 2和Smad 3是转化生长因子β（TGF β）信号传导的细胞内介质，其具有多种生物化学性质，但从几种细胞类型的功能分析中出现的数据表明，这两种Smad蛋白可能传达不同的细胞反应。因此，我们研究了Smad 2和Smad 3在介导TGF β的细胞生长抑制和促凋亡作用中的各自作用以及它们在上皮向间充质转化中的功能。为此，我们瞬时耗尽小鼠乳腺上皮细胞（NME）的Smad 2和/或Smad 3主要通过依赖于RNaseH诱导的mRNA降解的策略。分析了这种消耗对TGF β驱动的上皮向间充质转化的标志性事件的影响，包括上皮连接的溶解、应力纤维和粘着斑的形成、金属蛋白酶的活化和公认靶基因的转录调节。此外，我们通过微阵列分析研究了Smad 2和Smad 3敲低对TGF β调节的转录组的影响。我们的研究结果确定Smad 3作为一个关键因素，触发TGF β调节的事件，并归因于肿瘤抑制以及致癌活动，这种蛋白质。(Mol Cancer Res 2009;7（8）：1342-53）
Smad2 and Smad3 are intracellular mediators of transforming growth factor beta (TGF beta) signaling that share various biochemical properties, but data emerging from functional analyses in several cell types indicate that these two Smad proteins may convey distinct cellular responses. Therefore, we have investigated the individual roles of Smad2 and Smad3 in mediating the cytostatic and proapoptotic effects of TGF beta as well as their function in epithelial-to-mesenchymal transition. For this purpose, we transiently depleted mouse mammary epithelial cells (Nme) of Smad2 and/or Smad3 mainly by a strategy relying on RNaseH-induced degradation of mRNA. The effect of such depletion on hallmark events of TGF beta-driven epithelial-to-mesenchymal transition was analyzed, including dissolution of epithelial junctions, formation of stress fibers and focal adhesions, activation of metalloproteinases, and transcriptional regulation of acknowledged target genes. Furthermore, we investigated the effect of Smad2 and Smad3 knockdown on the TGF beta-regulated transcriptome by microarray analysis. Our results identify Smad3 as a key factor to trigger TGF beta-regulated events and ascribe tumor suppressor as well as oncogenic activities to this protein. (Mol Cancer Res 2009;7(8):1342-53)