School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, PR China.
School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong 266003, PR China; Laboratory of Marine Drugs and Biological Products, Pilot National Laboratory for Marine Science and Technology, Qingdao, Shandong 266235, PR China.
Int J Biol Macromol. 2023 Mar 1;230:123266. doi: 10.1016/j.ijbiomac.2023.123266. Epub 2023 Jan 14.
The discovery of new anti-cancer drugs targeting the PD-1/PD-L1 pathway has been a research hotspot in recent years. In this study, biological affinity ultrafiltration (BAU), UPLC-HRMS, molecular dynamic (MD) simulations and molecular docking methods were applied to search for endogenous active compounds that can inhibit the binding of PD-L1 to PD-1. We screened dozens of potential cancer related endogenous compounds. Surprisingly, cyclic adenosine monophosphate (cAMP) was found to have a direct inhibitory effect on the PD-1/PD-L1 binding with an in vitro IC value of about 36.4 ± 9.3 μM determined by homogeneous time-resolved fluorescence (HTRF) assay. cAMP could recover the proliferation of Jurkat T cells co-cultured with DU-145 cells and may suppress PD-L1 expression of DU-145 cells. cAMP was demonstrated to bind and induce PD-L1 dimerization by FRET assay, and also predicted by MD simulations and molecular docking. The finding of cAMP as a potential inhibitor directly targeting the PD-1/PD-L1 interaction could advance our understanding of the activity of endogenous compounds regulating PD-L1.
近年来，针对 PD-1/PD-L1 通路的新型抗癌药物的发现一直是研究热点。在这项研究中，应用生物亲和力超滤（BAU）、UPLC-HRMS、分子动力学（MD）模拟和分子对接方法，搜索能够抑制 PD-L1 与 PD-1 结合的内源性活性化合物。我们筛选了数十种潜在的与癌症相关的内源性化合物。令人惊讶的是，环磷酸腺苷（cAMP）被发现对 PD-1/PD-L1 的结合具有直接抑制作用，通过均相时间分辨荧光（HTRF）测定，其体外 IC 值约为 36.4±9.3 μM。cAMP 可以恢复与 DU-145 细胞共培养的 Jurkat T 细胞的增殖，并可能抑制 DU-145 细胞中 PD-L1 的表达。通过荧光共振能量转移（FRET）测定、MD 模拟和分子对接预测，证明 cAMP 可以结合并诱导 PD-L1 二聚化。cAMP 作为一种直接靶向 PD-1/PD-L1 相互作用的潜在抑制剂的发现，可以加深我们对内源性化合物调节 PD-L1 活性的认识。
