Ecto-nucleoside triphosphate diphosphohydrolase 1 (CD39) (ENTPD1)

Ecto-nucleoside triphosphate diphosphohydrolase 1 (ENTPD1), commonly known as CD39, is a cell-surface enzyme that serves as the rate-limiting step in the hydrolysis of extracellular adenosine triphosphate (ATP) and adenosine diphosphate (ADP) into adenosine monophosphate (AMP) [UniProt P49961]. In the purinergic signaling cascade, AMP is further processed by CD73 into adenosine, a potent immunosuppressive molecule that helps tumors evade the immune system by inhibiting effector T cells and natural killer cells [PubMed: 31053155]. Consequently, CD39 is highly expressed in the tumor microenvironment on various cells, including regulatory T cells (Tregs), myeloid-derived suppressor cells, and some cancer cells, making it a critical metabolic checkpoint [NIH Gene ID 953]. Beyond its role in oncology, ENTPD1 is vital for maintaining vascular homeostasis by regulating platelet aggregation through the removal of extracellular ADP [PubMed: 32669314]. Therapeutic strategies currently focus on monoclonal antibodies and small molecule inhibitors designed to block ENTPD1 activity, thereby shifting the tumor microenvironment from an adenosine-rich immunosuppressive state to an ATP-rich immunostimulatory state to enhance the efficacy of cancer treatments [NCBI: PMC7355152].

Other names

CD39NTPDase1Ecto-apyraseApyraseEcto-ATP diphosphohydrolase 1Vascular ATP diphosphohydrolase

Inhibition of the enzymatic conversion of extracellular ATP/ADP to AMP, thereby preventing the subsequent formation of immunosuppressive adenosine and maintaining pro-inflammatory ATP levels to stimulate anti-tumor immunity.