Ye Guiqin, Sun Xin, Li Jiuzhou, Mai Yuanyuan, Gao Ruilan, Zhang Jianbin
Cancer Center, Department of Medical Oncology, Key Laboratory of Tumor Molecular Diagnosisand Individualized Medicine of Zhejiang Province, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, 310014, China.
Clinical Laboratory, Yuhuan City Hospital, Taizhou, Zhejiang, 317600, China.
J Pharm Anal. 2024 Jun;14(6):100926. doi: 10.1016/j.jpha.2023.12.016. Epub 2023 Dec 22.
Lung cancer ranks the top of malignancies that cause cancer-related deaths worldwide. The leaves of L are traditional Chinese medicine widely applied in respiratory diseases. Our previous work has demonstrated the anti-lung cancer effect of secondary metabolites of mulberry leaf, but their mechanism of action has still not fully elucidated. We synthesized Moracin N (MAN)-Probe conjugated with alkyne to label lung cancer cells and identified protein targets by chemical proteomic analysis. MAN and its probe exerted similar growth-inhibitory effect on human lung cancer cells. Chemical proteomic results showed that MAN targeted the programmed death ligand 1 (PD-L1) checkpoint pathway and T cell receptor (TCR) signaling pathway, indicating its immune-regulatory function. Cell-free surface plasmon resonance (SPR) results showed the direct interaction of MAN with PD-L1 protein. Molecular docking analysis demonstrated that MAN bound to E158 residue of PD-L1 protein. MAN downregulated the expression levels of PD-L1 in a time- and dose-dependent manner and disrupted the PD-L1/programmed death 1 (PD-1) binding, including other secondary metabolites of mulberry leaves Guangsangon E (GSE) and Chalcomoracin (CMR). Human peripheral blood mononuclear cells (PBMCs) co-cultured with MAN-treated A549 cells, resulting in the increase of CD8 GZMB T cells and the decrease of CD8 PD-1 T cells. It suggested that MAN exerts anti-cancer effect through blocking the PD-L1/PD-1 signaling. , MAN combined with anti-PD-1 antibody significantly inhibited lung cancer development and metastasis, indicating their synergistic effect. Taken together, secondary metabolites of mulberry leaves target the PD-L1/PD-1 signaling, enhance T cell-mediated immunity and inhibit the tumorigenesis of lung cancer. Their modulatory effect on tumor microenvironment makes them able to enhance the therapeutic efficacy of immune checkpoint inhibitors in lung cancer.
肺癌是全球导致癌症相关死亡的恶性肿瘤之首。L的叶子是广泛应用于呼吸系统疾病的传统中药。我们之前的工作已经证明了桑叶次生代谢产物的抗肺癌作用,但其作用机制仍未完全阐明。我们合成了与炔烃共轭的桑色素N(MAN)探针来标记肺癌细胞,并通过化学蛋白质组学分析鉴定蛋白质靶点。MAN及其探针对人肺癌细胞具有相似的生长抑制作用。化学蛋白质组学结果表明,MAN靶向程序性死亡配体1(PD-L1)检查点通路和T细胞受体(TCR)信号通路,表明其免疫调节功能。无细胞表面等离子体共振(SPR)结果显示MAN与PD-L1蛋白直接相互作用。分子对接分析表明,MAN与PD-L1蛋白的E158残基结合。MAN以时间和剂量依赖性方式下调PD-L1的表达水平,并破坏PD-L1/程序性死亡1(PD-1)的结合,包括桑叶的其他次生代谢产物光桑素E(GSE)和查尔科莫拉辛(CMR)。与经MAN处理的A549细胞共培养的人外周血单核细胞(PBMC),导致CD8 GZMB T细胞增加和CD8 PD-1 T细胞减少。这表明MAN通过阻断PD-L1/PD-1信号发挥抗癌作用。此外,MAN与抗PD-1抗体联合使用可显著抑制肺癌的发展和转移,表明它们具有协同作用。综上所述,桑叶次生代谢产物靶向PD-L1/PD-1信号,增强T细胞介导的免疫并抑制肺癌的肿瘤发生。它们对肿瘤微环境的调节作用使它们能够增强免疫检查点抑制剂在肺癌中的治疗效果。