Transmembrane glycoprotein NMB (GPNMB) (GPNMB)

Transmembrane glycoprotein NMB (GPNMB), also known as Osteoactivin or DC-HIL, is a type I transmembrane protein that plays a multifaceted role in tissue homeostasis, immune regulation, and bone development [Wikipedia, NIH]. It is expressed in various cell types, including macrophages, dendritic cells, osteoblasts, and melanocytes, where it facilitates cell adhesion, migration, and differentiation [NIH, Frontiers]. In oncology, GPNMB is frequently overexpressed in aggressive tumors such as melanoma and triple-negative breast cancer, acting as a pro-tumorigenic factor that promotes metastasis and suppresses anti-tumor immunity by inhibiting T-cell activation through its interaction with syndecan-4 [NIH, AACR]. Conversely, in the central nervous system, GPNMB is induced by lysosomal stress and exhibits neuroprotective properties, making it a significant biomarker and potential target in neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) and Parkinson's disease [NIH, bioRxiv]. Therapeutic interventions targeting GPNMB include antibody-drug conjugates like glembatumumab vedotin, which deliver cytotoxic agents directly to cancer cells, and small molecules that modulate its expression to enhance neuroprotection or reduce inflammation [SCBT, NIH]. The protein's ability to be shed as a soluble fragment (sGPNMB) further extends its biological influence, serving as a measurable biomarker for disease progression and therapeutic efficacy [NIH, MDPI]. GPNMB also interacts with integrins and receptor tyrosine kinases to modulate downstream signaling pathways like PI3K/AKT and MAPK/ERK, which are critical for cell survival and tissue repair [NIH, ResearchGate]. Recent research has also highlighted its role in cardiovascular health, where it promotes heart repair following myocardial infarction by binding to the GPR39 receptor [Drug Target Review].

Other names

Glycoprotein nonmetastatic melanoma protein BOsteoactivinDC-HILDendritic cell-heparin integrin ligandDendritic cell heparan sulfate proteoglycan integrin-dependent ligandHGFINHematopoietic growth factor inducible neurokinin-1 typePLCA3NMB

Antibody-drug conjugate (ADC) targeting GPNMB-expressing cells; Immune checkpoint inhibition; Modulation of signaling pathways; Upregulation for neuroprotection