CD38 [AT1]

CD38, also called ADP-ribosyl cyclase, is a druggable ectoenzyme that uses nicotinamide adenine dinucleotide (NAD) as a substrate to generate second messengers. In particular, it synthesizes cyclic ADP-ribose, a second messenger for glucose-induced insulin secretion. CD38 also has cADPR hydrolase activity. It is preferentially expressed at both early and late stages of B- and T-cell maturation. In normal lymph nodes and tonsils, the antigen is detected mainly on B cells in germinal centers and plasma cells. An antibody to CD38 is helpful in the identification of plasma cells and tumors with plasmablastic differentiation. A prognostic value of CD38 in B-cell chronic lymphocytic leukemia (CLL) has been reported. Expression of CD38 is linked to unmutated IgVH genes and a worse prognosis. CD38 is involved in the generation of adenosine, which is implicated in tumor immune evasion. CD38 mRNA expression in metastatic castration-resistant prostate cancer (mCRPC) was most significantly associated with upregulated immune signaling pathways, and with interleukin (IL)-12, IL-23, and IL-2.