GATA zinc finger protein p66ß promotes breast cancer cell migration by acting as a co-activator of Snail.

ABSTRACT

The transcriptional repressor Snail induces EMT during embryonic development and tumor metastasis. Growing evidence indicates that Snail functions as a trans-activator to induce gene expression; however, the underlying mechanism remains elusive. Here, we report that Snail cooperates with GATA zinc finger protein p66ß to transactivate genes in breast cancer cells. Biologically, depletion of p66ß reduces cell migration and lung metastasis in BALB/c mice. Mechanistically, Snail interacts with p66ß and cooperatively induces gene transcription. Notably, a group of genes induced by Snail harbor conserved G-rich cis-elements (5'-GGGAGG-3', designated as G-box) in their proximal promoter regions. Snail directly binds to G-box via its zinc fingers and transactivates the G-box-containing promoters. p66ß enhances Snail binding affinity to G-box, whereas depletion of p66ß results in a decreased binding affinity of Snail to the endogenous promoters and concomitantly reduces the transcription of Snail-induced genes. Taken together, these data demonstrated that p66ß is critical for Snail-mediated cell migration by acting as a co-activator of Snail to induce genes containing G-box elements in the promoters.