5'-nucleotidase (CD73) (CD73)

5'-nucleotidase (CD73) is a glycosylphosphatidylinositol (GPI)-anchored cell-surface enzyme that catalyzes the final step of the extracellular ATP-to-adenosine conversion pathway by hydrolyzing adenosine monophosphate (AMP) into adenosine (UniProt P21589). This enzymatic process is a key metabolic checkpoint in the tumor microenvironment, where high levels of adenosine act as a potent immunosuppressant by binding to purinergic P1 receptors, specifically the A2A and A2B subtypes, on various immune cells (PubMed: 31515470). By engaging these receptors, adenosine inhibits the activity of T cells and natural killer cells while promoting the suppressive functions of regulatory T cells and myeloid-derived suppressor cells (PubMed: 28970190). Consequently, the CD73-adenosine axis is a major target in immuno-oncology, with therapeutic strategies focusing on monoclonal antibodies and small-molecule inhibitors designed to block CD73 activity and restore anti-tumor immunity (ClinicalTrials.gov). Beyond its role in cancer, CD73-mediated adenosine generation is essential for maintaining tissue homeostasis, regulating vascular permeability, and modulating inflammatory responses (PubMed: 23567511).

Other names

Ecto-5'-nucleotidaseNT5ECluster of Differentiation 735'-NTEcto-5'-NT

Inhibition of the enzymatic conversion of AMP to adenosine, thereby preventing the activation of immunosuppressive purinergic receptors (A2AR/A2BR) in the tumor microenvironment.