Transforming Growth Factors β1 (TGF-β1) and TGF-β2 Promote Glioma Cell Migration via Up-Regulation of αVβ3 Integrin Expression

The migratory behaviour of malignant gliomas relies on the interaction of integrins with extracellular matrix (ECM) components. Transforming growth factor-β1 (TGF-β1) potently stimulates glioma cell motility whereas TGF-β2 is known for its immunosuppressive properties. Here, we show that both TGF-β1 and TGF-β2 promote migration of glioma cells. In parallel, TGF-β1 and TGF-β2 induce αV and β3 intergrin mRNA expression and enhance cell surface expression of αVβ3 integrin. TGF-β-mediated promotion of migration is abrogated by echistatin, a Arg-Gly-Asp (RGD) peptide antagonist of αVβ3 integrin, and by a neutralizing anti-αVβ3 integrin antibody. Taken together, we report a novel mechanism by which TGF-β modulates cell ECM interactions and promotes glioma cell motility.