Schematic Model of IGF-1 and TGF-β1 signaling in MCF-7 breast cancer cells. 1) IGF-1 binds IGF-1 receptor. 2) IGF-1 receptor signals through the PI3K and MAPK pathways. 3) IGF-1 signaling causes transcriptional activation of unknown target genes (?). 4) Unknown target protein(s) (?) are secreted and activate MMPs. 5) Active MMPs are available to activate latent molecules in the ECM, such as TGF-β. 6) Active TGF-β1 binds TGF-β1 receptor. 7) TGF-β signaling causes nuclear localization of β-catenin. 8) TGF-β signaling causing transcriptional activation of genes that result in an EMT.
Walsh and Damjanovski Cell Communication and Signaling 2011 9:10 doi:10.1186/1478-811X-9-10