Discovery of a novel CD39 inhibitor by DNA-encoded library screening

The ATP-adenosine pathway, as a key regulator of adaptive immunity, can regulate tumor growth and proliferation, which is an important direction of anti-tumor immunity research. As a rate-limiting extracellular nucleotidase in eATP hydrolysis, CD39 is a promising target for anticancer therapy. In this study, we discovered a novel CD39 small molecule inhibitor (compound 338) by DNA-encoded library (DEL) technology. Subsequently, compound 338 was synthesized and tested with promising inhibitory effect which IC₅₀ value was 68.7 nM against CD39. It also showed moderate anti-proliferative effects on tumor cells and low toxicity on normal cell lines. Meanwhile, molecular docking and SPR results demonstrated that 338 had a robust binding interaction with CD39. The druggability of 338 was predicted. In conclusion, the novel compound 338 showed strong CD39 inhibitory activity and good druggability, which can be used as a potential anti-tumor therapeutic agent and can be optimized in further studies.