112 Lab., School of Chemistry and Biotechnology Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Beijing Key Laboratory of Traditional Chinese Medicine Basic Research on Prevention and Treatment for Major Diseases, Experimental Research Center, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
112 Lab., School of Chemistry and Biotechnology Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Biomed Pharmacother. 2020 Nov;131:110673. doi: 10.1016/j.biopha.2020.110673. Epub 2020 Sep 1.
Chlorogenic acid, an important active component of coffee with anti-tumor activities, has been found for a hundred years. However, the lack of understanding about its target proteins greatly limits the exploration of its anti-tumor molecular mechanisms and clinical applications. Here, in vitro and animal experiments showed that chlorogenic acid had a significant inhibitory effect on the proliferation of A549 cells. The ability of chlorogenic acid to naturally emit fluorescence was exploited to screen its target proteins while avoiding false positives brought about by chemical modifications when using fluorescent tags. Consequently, we identified and verified annexin A2 as a covalent binding target of chlorogenic acid in A549 cells. We also discovered that chlorogenic acid inhibits the binding of annexin A2 to p50 subunit thereby inhibiting the expression of downstream anti-apoptotic genes cIAP1 and cIAP2 of the NF-κB signaling pathway in A549 cells in vitro and in vivo. Moreover, we found that chlorogenic acid hindered the binding of annexin A2 to actin possibly causing inhibition of tumor cell cycle and migration. Thus, this work demonstrates that chlorogenic acid binds annexin A2, causing a decrease in the expression of NF-κB downstream anti-apoptotic genes, and inhibiting the proliferation of A549 cells in vivo and in vitro.
绿原酸是咖啡中一种具有抗肿瘤活性的重要活性成分，已经被发现了一百年。然而，人们对其靶蛋白的了解甚少，这极大地限制了对其抗肿瘤分子机制和临床应用的探索。在这里，体外和动物实验表明，绿原酸对 A549 细胞的增殖具有显著的抑制作用。利用绿原酸自然发出荧光的能力，在筛选其靶蛋白时，避免了使用荧光标记物时化学修饰带来的假阳性。因此，我们鉴定并验证了膜联蛋白 A2 是 A549 细胞中绿原酸的共价结合靶标。我们还发现，绿原酸抑制了膜联蛋白 A2 与 p50 亚基的结合，从而抑制了 NF-κB 信号通路下游抗凋亡基因 cIAP1 和 cIAP2 在 A549 细胞中的表达，无论是在体外还是在体内。此外，我们发现绿原酸可能阻碍了膜联蛋白 A2 与肌动蛋白的结合，从而抑制肿瘤细胞周期和迁移。因此，这项工作表明，绿原酸与膜联蛋白 A2 结合，导致 NF-κB 下游抗凋亡基因的表达减少，从而抑制了 A549 细胞在体内和体外的增殖。
