Transforming growth factor beta (TGF(beta) induces epithelial-mesenchymal transition (EMT), which correlates with sternness and invasiveness. Mesenchymal-epithelial transition (MET) is induced by... Show moreTransforming growth factor beta (TGF(beta) induces epithelial-mesenchymal transition (EMT), which correlates with sternness and invasiveness. Mesenchymal-epithelial transition (MET) is induced by TGF beta withdrawal and correlates with metastatic colonization. Whether TGF beta promotes sternness and invasiveness simultaneously via EMT remains unclear. We established a breast cancer cell model expressing red fluorescent protein (RFP) under the E-cadherin promoter. In 2D cultures, TGF beta induced EMT, generating RFPlow cells with a mesenchymal transcriptome, and regained RFP, with an epithelial transcriptome, after MET induced by TGF beta withdrawal. RFPlow cells generated robust mammospheres, with epithelio-mesenchymal cell surface features. Mammospheres that were forced to adhere generated migratory cells, devoid of RFP, a phenotype which was inhibited by a TGF beta receptor kinase inhibitor. Further stimulation of RFPlow mammospheres with TGF beta suppressed the generation of motile cells, but enhanced mammosphere growth. Accordingly, mammary fat-pad-transplanted mammospheres, in the absence of exogenous TGF beta treatment, established lung metastases with evident MET (RFPhigh cells). In contrast, TGF beta-treated mammospheres revealed high tumour-initiating capacity, but limited metastatic potential. Thus, the biological context of partial EMT and MET allows TGF beta to differentiate between pro-sternness and pro-invasive phenotypes. Show less
Buijs, J.T.; Horst, G. van der; Hoogen, C. van den; Cheung, H.; Rooij, B. de; Kroon, J.; ... ; Pluijm, G. van der 2012
