SB-431542 inhibits TGF-beta1-induced fibronectin mRNA formation while displaying no measurable cytotoxicity in the 48 h XTT assay. SB-431542 (1 μM) significantly reduced the TGFβ–induced nuclear accumulation of Smad proteins. The IC50 for inhibiting TGFβ–induced nuclear fluorescence is approximately 50 nM. BMP-stimulated Smad1 nuclear fluorescence in MG63 cells was unaffected by SB-431542. the synergistic action of two inhibitors of SMAD signaling, Noggin and SB431542, is sufficient to induce rapid and complete neural conversion of >80% of hES cells under adherent culture conditions.
体内研究:SB-431542 augmented the capacity of bone marrow dendritic cells (BM-DCs) and human DCs to incorporate FITC-conjugated dextran. Intraperitoneal administration of SB-431542 initiated 3 and 7 days after the implantation of colon-26 cancer cells into the peritoneal cavity of BALB/c mice significantly induced CTL activity against colon-26. SB-431542 significantly inhibited lung metastasis from transplanted 4T1 mammary tumors in Balb/c mice.