ABSTRACT
The methyltransferase enhancer of zeste homolog 2 (EZH2) regulates gene expression, and aberrant EZH2 expression and signaling can drive fibrosis and cancer. However, it is not clear how chemical and mechanical signals are integrated to regulate EZH2 and gene expression. We show that culture of cells on stiff matrices in concert with transforming growth factor (TGF)-β1 promotes nuclear localization of EZH2 and an increase in the levels of the corresponding histone modification, H3K27me3, thereby regulating gene expression. EZH2 activity and expression are required for TGFβ1- and stiffness-induced increases in H3K27me3 levels as well as for morphological and gene expression changes associated with epithelial–mesenchymal transition (EMT). Inhibition of Rho associated kinase (ROCK) proteins or myosin II signaling attenuates TGFβ1-induced nuclear localization of EZH2 and decreases H3K27me3 levels in cells cultured on stiff substrata, suggesting that cellular contractility, in concert with a major cancer signaling regulator TGFβ1, modulates EZH2 subcellular localization. These findings provide a contractility-dependent mechanism by which matrix stiffness and TGFβ1 together mediate EZH2 signaling to promote EMT.
Footnotes
Author contributions
Conceptualization: E.W.G.; Methodology: J.L.S.; Formal analysis: J.L.S., Z.T.V., A.S., E.S., S.K., C.S.S.; Investigation: J.L.S., Z.T.V., A.S., E.S., S.K., C.S.S.; Data curation: J.L.S., Z.T.V., A.S., E.S., S.K., C.S.S., E.W.G.; Writing - original draft: J.L.S.; Writing - review & editing: J.L.S., Z.T.V., A.S., E.S., S.K., C.S.S., E.W.G.; Visualization: J.L.S., E.W.G.; Supervision: E.W.G.; Project administration: E.W.G.; Funding acquisition: E.W.G.
Funding
This work was supported by the National Science Foundation (CMMI-1751785 to E.W.G., EEC-1950639 to E.W.G.), National Aeronautics and Space Administration (PSGC to J.L.S.), and the Penn State Department of Chemical Engineering (Biofellowship to Z.T.V.). E.S. was supported by the National Science Foundation (EEC-1950639).
Data availability
All relevant data and resources can be found within the article and its supplementary information.
