Fig. 2.

POSTN can activate the TGF-β/Smad pathway to accelerate the occurrence and development of fibrosis and cancer. (1) POSTN can induce the phosphorylation of Smad3 with the stimulation of TGF-β, upregulating the expression of SERPINE1, CTGF, IGFBP-3, and IL-11 to promote pulmonary fibrosis. This process can be prevented by an inhibitor of integrin αvβ3, CP4715. (2) POSTN can decrease the level of protective Smad7, subsequently upregulating the expression of α-SMA and EGR-1 and downregulating the level of MMP-1 to promote skin fibrosis. (3) POSTN siRNA is transfected into the cells expressing SULF2 and it was found that the expression of VEGFB, MMP-2, MMP-9, PDGFA, and PDGFB decreased through the TGF-β/Smad pathway. This process can be inhibited by SULF2, which eventually induces the occurrence of hepatocellular carcinoma. (4) POSTN can promote migration and invasion of ovarian cancer by activating the TGF-β/Smad pathway