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.