腫瘤轉(zhuǎn)移是一個復雜的過程,，有很多促癌基因基因參與其中過程。轉(zhuǎn)移相關(guān)基因1（MTA1）是一個能調(diào)控多個靶蛋白的基因,，該基因的表達有助于促進腫瘤轉(zhuǎn)移過程,。
MTA1表達已被證明與多種具有侵略性癌癥類型密切相關(guān)包括乳腺癌。最新一項研究表明,，MTA1能調(diào)控Smad7，SMAD7是轉(zhuǎn)化生長因子β（TGFbeta）信號的一個組成部分,。TGFbeta信號通過Smad蛋白家族轉(zhuǎn)導到細胞核蛋白,，其中就包括Smad7，Smad7是一個抑制SMAD蛋白的分子,，起著負調(diào)節(jié)TGFbeta的作用,。
降低MTA1的表達，Smad7的表達會增加,。用組蛋白去乙酰酶抑制劑處理細胞后,，Smad7的表達也增加。研究發(fā)現(xiàn)MTA1被招募至Smad7蛋白的啟動子區(qū)域,。
Smad7能抑制Smad2和Smad3的活化,，該研究表明MTA1被抑制后，SMAD蛋白的表達水平就會水平下降,，同時MTA被抑制后,，Smad7的下游調(diào)控的一系列蛋白也會降低表達,。可見MTA1的表達是調(diào)節(jié)TGFbeta信號的重要成分,，而Smad7通過調(diào)節(jié)MTA1的表達可能有助于腫瘤的形成和轉(zhuǎn)移,。（生物谷：Bioon.com）
編譯自：MTA1-mediated transcriptional repression of SMAD7 in breast cancer cell lines
doi:10.1016/j.ejca.2012.06.019
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PMID:
MTA1-mediated transcriptional repression of SMAD7 in breast cancer cell lines
Shimul Salota, Rajiv Gudea
Metastasis is a complex process facilitated by the action of several genes. Metastasis associated 1 (MTA1) gene is one such gene which assists the process of metastasis by regulating several molecular targets. MTA1 acts as part of a nucleosome remodelling and histone deacetylation complex, which is involved in transcriptional regulation. Expression of MTA1 has been shown to be closely correlated with aggressiveness in several types of cancers, including breast cancer. In the present study we show that MTA1 regulates SMAD7, a component of Transforming growth factor beta (TGFbeta) signalling. TGFbeta signals are transduced to the nucleus by the Smad family of proteins, which includes Smad7, an inhibitory SMAD, which acts as a negative regulator of TGFbeta. On knockdown of MTA1, SMAD7 expression increases. Treating cells with a histone deacetylase inhibitor also increases SMAD7 expression. MTA1 is recruited to SMAD7 promoter region. SMAD7 inhibits activation of SMAD2 and SMAD3 and we show that the levels of these active SMAD proteins are decreased in cells expressing shRNA against MTA1. We further show that on MTA1 knockdown, the expression of downstream targets of SMAD7 is decreased. MTA1 thus appears to regulate a key inhibitor of TGFbeta signalling, SMAD7. By regulating molecules like SMAD7 MTA1 might assist the process of tumourigenesis and metastasis
