GRN

Granulin precursor (GRN) is a multifunctional secreted glycoprotein encoded by the GRN gene located on chromosome 17q21, belonging to the growth factor superfamily. GRN plays a role in various biological processes, including promoting growth and development, tissue repair, affecting macrophage function, and regulating the immune system. It is widely expressed in the nervous system during early embryonic development, promoting neuronal axon growth and repair, increasing synaptic branching, and serving as an important neurotrophic factor. In addition, GRN can directly promote the proliferation, differentiation, and migration of vascular endothelial cells and fibroblasts, accelerating wound healing. In terms of tumor formation and invasion, overexpression of GRN promotes tumor growth and stimulates tumor cell proliferation through activation of signaling pathways such as MAPK/ERK, PI3K/AKT, and FAK. GRN is also a potential antagonist of tumor necrosis factor (TNF-α), inhibiting TNF-α-mediated inflammatory responses and thereby regulating immune-inflammatory reactions. Some studies have indicated that AGRN (related to GRN) promotes the progression of lung adenocarcinoma by activating the Notch signaling pathway and may serve as a therapeutic target. These functions and the involvement of signaling pathways indicate that GRN plays an important regulatory role in various diseases and may become a new target for future treatment strategies.