Ninjurin-2 (NINJ2)

Ninjurin-2 (NINJ2) is a cell surface homophilic adhesion molecule that plays an adaptive role in response to nerve injury and is upregulated in Schwann cells following nerve damage, where it promotes neurite outgrowth and nerve regeneration. It is a double transmembrane protein with homology to NINJ1 but shows distinct expression predominantly in hematopoietic and lymphatic tissues. NINJ2 also functions in endothelial cell inflammation, modulates NF-κB/c-Jun signaling through TLR4 interactions, and has been implicated in the regulation of genes related to inflammation and immune response. Overexpression or dysregulation of NINJ2 has been associated with several diseases, including cancer (where it promotes cell survival and proliferation, notably in colorectal and glioma cells), cardiovascular and neuroinflammatory diseases, and stroke susceptibility. It can form complexes with several receptor tyrosine kinases (EGFR, PDGFRα/β, FGFR) to potentiate PI3K/Akt and Erk signaling pathways, and is subject to regulation by the tumor suppressor p53, with which it forms a mutual feedback loop influencing cell growth and senescence outcomes. NINJ2 is a candidate diagnostic and prognostic marker in oncology and neurology but currently lacks validated small-molecule or antibody therapeutics.

Other names

NINJ2nerve injury-induced protein 2ninjurin 2Ninjurin-2

Not directly established for drugs, but NINJ2 modulates receptor tyrosine kinase (RTK: EGFR, PDGFRα/β, FGFR) pathways and downstream PI3K/Akt/Erk signaling in cancer cells. Modulates p53 expression and is regulated by p53, forming a feedback loop. Acts as an adaptor protein for RTK signaling in cancer. Modulates Toll-like receptor 4 (TLR4)–mediated NF-κB and c-Jun signaling in inflammation.