An FGFR inhibitor converts the tumor promoting effect of TGF-β by the induction of fibroblast-associated genes of hepatoma cells

Tumors consistently mimic wound-generating chronic inflammation; however, why they do not heal like wounds with fibrotic scars remains unknown. The components of the tumor microenvironment, such as transforming growth factor β (TGF-β) and fibroblast growth factors (FGFs), may account for this phenomenon. Tumor formation involves continuous activation of the FGF pathway, whereas the repair of tissue injury is a self-limiting process accompanied with controlled activation of the FGF pathway. In the tumor microenvironment TGF-β increases the secretion of FGFs, further promoting the malignant biological properties of tumors. However, during wound healing, sufficient TGF-β together with moderate FGFs lead to matrix deposition and the formation of fibrotic scars. In the present study, TGF-β1 combined with AZD4547, an FGF receptor (FGFR) inhibitor, transformed hepatoma cells into less malignant fibroblast-like cells with respect to morphology, physiological properties, and gene expression profiles. In vivo experiments showed that TGF-β1 combined with AZD4547 not only inhibited tumor growth but also promoted tumor parenchyma fibrosis. Our results indicate that FGFR inhibitor treatment converts the effect of TGF-β on the hepatocellular carcinoma cells from tumor promotion into tumor inhibition by enhancing the induction effect of TGF-β on some fibroblast-associated genes. Converting human liver cancer cells into less malignant fibroblast-like cells and inducing tumor parenchyma cell fibrosis provides an alternative strategy for limiting tumor progression.