DDR2

DDR2 (discoidin domain receptor 2) is a collagen-activated receptor tyrosine kinase that regulates cell-collagen interactions in normal and pathological tissue contexts[1]. Mechanistically, type I collagen activates DDR2 and promotes Src and Shc signaling, linking extracellular matrix sensing to intracellular phosphorylation responses[2]. In cartilage disease models, DDR2 activation induces MMP-13, connecting collagen receptor signaling with matrix degradation in osteoarthritis-related cartilage damage[3]. In breast cancer models, collagen I-activated DDR2 stabilizes SNAIL1 through Src-dependent ERK2 activity, supporting invasion, migration, epithelial-mesenchymal transition, and metastasis[4]. Compared with related isoforms, DDR1 is mainly associated with epithelial cells, whereas DDR2 is mainly associated with mesenchymal cells, making DDR2 especially relevant to fibroblast-rich stroma, cartilage, and collagen-dense tumor microenvironments[1]. In lung squamous cell carcinoma, DDR2 kinase mutations occur in a defined patient subset and confer sensitivity to Dasatinib (HY-10181) in experimental models[5]. For experimental applications, the extracellular allosteric inhibitor WRG-28 blocks DDR2-collagen interaction, inhibits tumor invasion and migration, and reduces metastatic breast tumor cell colonization in lungs[6].