Cell Rep.  2020  Dec  08.  pii:  S2211-1247(20)31462-5. [Epub  ahead  of  print]33(10): 108473
Huihui Fan, 
Huda I Atiya, 
Yeh Wang, 
Thomas R Pisanic, 
Tza-Huei Wang, 
Ie-Ming Shih, 
Kelly K Foy, 
Leonard Frisbie, 
Ronald J Buckanovich, 
Alison A Chomiak, 
Rochelle L Tiedemann, 
Scott B Rothbart, 
Chelsea Chandler, 
Hui Shen, 
Lan G Coffman.
 
  A role for cancer cell epithelial-to-mesenchymal transition (EMT) in cancer is well established. Here, we show that, in addition to cancer cell EMT, ovarian cancer cell metastasis relies on an epigenomic mesenchymal-to-epithelial transition (MET) in host mesenchymal stem cells (MSCs). These reprogrammed MSCs, termed carcinoma-associated MSCs (CA-MSCs), acquire pro-tumorigenic functions and directly bind cancer cells to serve as a metastatic driver/chaperone. Cancer cells induce this epigenomic MET characterized by enhancer-enriched DNA hypermethylation, altered chromatin accessibility, and differential histone modifications. This phenomenon appears clinically relevant, as CA-MSC MET is highly correlated with patient survival. Mechanistically, mirroring MET observed in development, MET in CA-MSCs is mediated by WT1 and EZH2. Importantly, EZH2 inhibitors, which are clinically available, significantly inhibited CA-MSC-mediated metastasis in mouse models of ovarian cancer.
Keywords:  EZH2; WT1; carcinoma-associated mesenchymal stem cells; epigenomic reprogramming; mesenchymal-to-epithelial transition; metastasis; ovarian cancer; tumor microenvironment