DDR1-IN-1 is a type II, subtype-selective discoidin domain receptor (DDR) tyrosine kinase inhibitor (DDR1/2 IC50 = 105 nM/413 nM) that effectively blocks collagen-induced DDR1 pY513 autophosphorylation in U2OS cells (EC50 = 86.76 nM) with excellent selectivity over a panel of >380 kinases. DDR1-IN-1 inhibits DDR2-mediated MT1-MMP activation in human rheumatoid synovial fibroblasts (RASF) upon collagen stimulation (IC50 < 2.5 μM) and enhances PI3K/mTOR inhibitor GSK2126458 antiproliferation efficacy in SNU-1040 colorectal cancer culture (123%, 70%, 50% of control, respectively, post 48-hr 250 nM DDR1-IN-1, 82.5 nM GSK2126458, or combined treatment). ent). ned treatment).
DDR1-IN-1 protects cells from apoptosis by inhibiting collagen-mediated Bcl-2-interacting killer (BIK) induction at both mRNA and protein levels.