A2B adenosine receptors (A2BARs) are in the focus of interest as drug targets in (immuno)oncology since antagonists show anti-proliferative, anti-angiogenic, anti-metastatic, and immunostimulatory properties. Additional (poten-tial) indications for A2BAR antagonists include inflammatory (pulmonary, colon) and autoimmune diseases, pain, fibrosis, infectious diseases, diabetes, and more. Agonists were found to exhibit cardioprotective properties. The A2BAR is most closely related to the A2AAR subtype. Both are Gs protein-coupled receptors, but the A2BAR is additionally coupled to Gq proteins. A2BAR expression is upregulated under pathological conditions (hypoxia, inflammation, ischemia) and on many cancer cells. A2BARs form stable heteromeric complexes with A2AARs when co-expressed, and thereby completely block A2AAR signaling. There is still a lack of potent, selective, and fully efficacious A2BAR agonists, while structurally diverse potent and selective competitive antagonists for A2BARs have become available. The first positive and negative allosteric modulators for A2BARs were recently described. For the labeling of A2BARs, antagonist radioligands have been developed, and recently the first potent and selective fluorescent ligands were reported.
- A adenosine receptor
ASJC Scopus subject areas