LRRC15 (Leucine-Rich Repeat-Containing 15) is a transmembrane protein belonging to the leucine-rich repeat (LRR) superfamily, known for its role in protein-protein interactions and cellular signaling. It is characterized by extracellular LRR domains, a transmembrane region, and a short cytoplasmic tail. LRRC15 is minimally expressed in most normal tissues but is upregulated in pathological conditions, particularly in cancer and fibrotic diseases. In cancer, it is highly expressed in stromal cells, such as cancer-associated fibroblasts (CAFs), and on the surface of certain tumor cells, including mesenchymal glioblastoma, pancreatic ductal adenocarcinoma, and triple-negative breast cancer. Its expression correlates with tumor progression, immune evasion, and therapeutic resistance. In fibrosis, LRRC15 is overexpressed in activated myofibroblasts, contributing to extracellular matrix remodeling.
LRRC15 antibodies are tools or therapeutic agents designed to target this protein. Research-grade antibodies enable the study of LRRC15's spatial expression, biological functions, and interactions with ligands like fibrillar collagens. Therapeutically, anti-LRRC15 antibodies are explored for their potential to inhibit tumor-stroma crosstalk, deliver cytotoxic payloads (e.g., antibody-drug conjugates), or enhance immune cell targeting (e.g., CAR-T therapies). Recent clinical trials have evaluated LRRC15-directed therapies, highlighting its emerging role as a biomarker and druggable target in oncology and fibrotic disorders. However, its precise mechanistic contributions remain under investigation, necessitating further research to optimize antibody-based strategies.