Complement C1q tumor necrosis factor-related protein 8 (C1QTNF8)

Complement C1q tumor necrosis factor-related protein 8 (C1QTNF8, also known as CTRP8) is a secreted protein belonging to the C1q/TNF superfamily and is predicted to form collagen trimers and act predominantly in the extracellular space[3]. CTRP8 is a novel ligand for the relaxin family peptide receptor 1 (RXFP1), a G protein-coupled receptor, particularly in glioblastoma cells which lack the classical RXFP1 ligands. The interaction between CTRP8 and RXFP1 activates intracellular cAMP signaling, promotes cell migration, and induces secretion of cathepsin B—an enzyme linked to tumor invasiveness[1]. Therapeutically, targeting the CTRP8-RXFP1 system and its downstream effectors (PI3K, PKC, cathepsin B) offers potential for glioblastoma intervention. The protein is also part of a larger family structurally related to both complement proteins and TNF superfamily members, and additional roles in other tissues and cancers are possible given the biology of its family members[3].

Other names

C1q and TNF related 8C1QTNF8Complement C1q tumor necrosis factor-related protein 8CTRP8C1q/TNF-related protein 8UNQ5829/PRO19648

Blockade of ligand-receptor interaction (CTRP8 binding to RXFP1); Inhibition of downstream signaling (PI3K and protein kinase C pathways); Inhibition of cathepsin B activity.