A2b adenosine receptor and cancer

Abstract

There are four subtypes of adenosine receptors (ARs), named A1, A2A, A2B and A3, all of which are G protein-coupled receptors (GPCRs). Locally produced adenosine is a suppressant in anti-tumor immune surveillance. The A2B AR, coupled to both Gαs and Gαi G proteins, is one of the several GPCRs that are expressed in a significantly higher level in certain cancer tissues, in comparison to adjacent normal tissues. There is growing evidence that the A2B AR plays an important role in tumor cell proliferation, angiogenesis, metastasis, and immune suppression. Thus, A2B AR antagonists are novel, potentially attractive anticancer agents. Several antagonists targeting A2B AR are currently in clinical trials for various types of cancers. In this review, we first describe the signaling, agonists, and antagonists of the A2B AR. We further discuss the role of the A2B AR in the progression of various cancers, and the rationale of using A2B AR antagonists in cancer therapy.