Adenosine Receptors
Adenosine is often elevated in the tumor microenvironment, and its binding to adenosine A2A and A2Breceptors (A2AAR and A2BAR) on immune cells leads to suppression of anti-tumor immune responses (Haskó, Linden, Cronstein, & Pacher, 2008; Leone & Emens, 2018). Activation of the A2AAR inhibits the activity of cytotoxic T cells and natural killer cells while promoting the expansion of immunosuppressive regulatory T cells (C. Sun, Wang, & Hao, 2022). And activation of the A2BAR has been found to lower the abundance of B cells, inhibit natural killer cells activity and cytokine production (Faraoniet al. , 2023; Han, Dong, Hu, Wang, & Wang, 2024). The adenosine receptors have become a focus area in cancer immunotherapy research, with efforts to develop selective antagonists targeting A2AAR and A2BAR (Leone & Emens, 2018). Currently, several A2AAR/A2BAR antagonists are under clinical trials for different types of cancer (Chen, Chang, Yu, & Sung, 2024; Franco, Rivas-Santisteban, Navarro, & Reyes-Resina, 2021).