The transcriptional regulators TAZ and YAP direct Transforming Growth Factor-beta-induced tumorigenic phenotypes in breast cancer cells

Uncontrolled Transforming growth factor-beta (TGF) signaling promotes aggressive metastatic properties in late-stage breast cancers. However, how TGF-mediated cues are directed to induce late-stage tumorigenic events is poorly understood, particularly given that TGF has clear tumor suppressing activity in other contexts. Here we demonstrate that the transcriptional regulators TAZ and YAP (TAZ/YAP), key effectors of the Hippo pathway, are necessary to promote and maintain TGF-induced tumorigenic phenotypes in breast cancer cells. Interactions between TAZ/YAP, TGF-activated SMAD2/3, and TEAD transcription factors reveal convergent roles for these factors in the nucleus. Genome-wide expression analyses indicate that TAZ/YAP, TEADs and TGF-induced signals coordinate a specific pro-tumorigenic transcriptional program. Importantly, genes cooperatively regulated by TAZ/YAP, TEAD, and TGF, such as the novel targets NEGR1 and UCA1, are necessary for maintaining tumorigenic activity in metastatic breast cancer cells. Nuclear TAZ/YAP also cooperate with TGF signaling to promote phenotypic and transcriptional changes in non-tumorigenic cells to overcome TGF repressive effects. Our work thus identifies crosstalk between nuclear TAZ/YAP and TGF signaling in breast cancer cells, revealing novel insight into late-stage disease-driving mechanisms.

12

Hiemer SE, Szymaniak AD, Varelas X