ABSTRACT
Previous studies have revealed Twist,a basic helix-loop-helix transcription factor,plays an important role in breast cancer metastasis.To clarify the molecular mechanism of its involvement in cancer metastasis,Twist was silenced by RNAi in highly metastatic 4T1 cells.Then microarray chips were used to investigate the gene-expression pattern of the Twist-knockdown 4T1 cells and the normal 4T1 cells.The results indicated that silencing of Twist significantly suppressesed lung metastasis of 4T1 cells in vivo.Direct comparison of gene-expression profiles showed that 167 genes in Twist-knockdown cells differed dramatically in expression levels from those in control cells.Among the 167 genes,26 well-known tumor-associated genes,including 15 up-regulated and 11 down-regulated genes were found.These genes appear to be regulated by Twist during breast tumorigenesis.The findings provide new insights into the mechanism by which Twist is involved in tumorigenesis.