MIA

Melanoma inhibitory activity (MIA), also termed cartilage-derived retinoic acid-sensitive protein (CD-RAP), is a secreted 11-kDa protein encoded by the MIA gene. It functions as a critical modulator of cell-matrix interactions through binding to α4β1, α5β1, and αvβ3 integrins, thereby inhibiting integrin-mediated cell adhesion and promoting tumor cell invasion. MIA operates within the MAPK/ERK and PI3K/AKT signaling pathways to facilitate epithelial-mesenchymal transition in malignant cells. Clinically elevated in melanoma, chondrosarcoma, and breast cancer, MIA expression correlates with metastatic progression and poor prognosis. Its role in disrupting extracellular matrix communication has positioned MIA as both a diagnostic biomarker and therapeutic target. Preclinical studies focus on MIA-neutralizing antibodies and peptide inhibitors, with Phase I/II trials investigating anti-MIA immunotherapies for advanced melanoma (NCT04267237). Paradoxically, MIA demonstrates chondroprotective effects in osteoarthritis models through SOX9-mediated cartilage matrix preservation.