Our lab has recently reported that AKT activates heat shock factor 1 (HSF1), leading to epithelial-to-mesenchymal transition in HER2-positive breast cancer.
Our results show for the first time that HER2/ErbB2 overexpression controls HSF1 activity, with subsequent stabilization of numerous tumor-promoting HSP90 clients such as MIF, AKT and HSF1 itself, thereby causing a robust promotion in tumor growth in HER2-positive breast cancer.
The proliferation of certain human HER2-positive breast cancer lines also requires HSF1, as its knockdown led to upregulation of p21 and/or decrease in survivin, precipitating growth arrest.