背景:程序性细胞死亡配体1(PD-L1)在肿瘤细胞中过度表达,导致肿瘤细胞逃避T细胞杀伤,促进肿瘤细胞存活,细胞增殖,迁移,入侵,和血管生成。Britannin是一种具有抗癌药理作用的天然产物。
目的:在这项工作中,我们研究了Britannin的抗癌潜力,并探讨了Britannin是否通过抑制肿瘤细胞中PD-L1的表达来介导其作用。
方法:体外,通过MTT法研究了Britannin抑制PD-L1表达的机制,同源建模和分子对接,RT-PCR,西方印迹,免疫共沉淀,和免疫荧光。肿瘤杀伤活性的变化,细胞增殖,细胞周期,迁移,入侵,通过T细胞杀伤试验分析血管生成,EdU标签,菌落形成,流式细胞术,伤口愈合,基质胶transwell侵入,和管的形成,分别。在体内,在HCT116细胞异种移植模型中评估了Britannin的抗肿瘤活性.
结果:Britannin通过抑制PD-L1蛋白的合成降低肿瘤细胞中PD-L1的表达,但不影响PD-L1蛋白的降解。Britannin还通过mTOR/P70S6K/4EBP1途径抑制HIF-1α表达,并通过Ras/RAF/MEK/ERK途径抑制Myc激活。机械上,Britannin通过阻断HIF-1α与Myc的相互作用抑制PD-L1的表达。此外,Britannin可以通过抑制PD-L1增强细胞毒性T淋巴细胞的活性,抑制肿瘤细胞的增殖和血管生成。最后,通过证明Britannin在鼠异种移植模型中的抗肿瘤活性来证实体内观察。
结论:Britannin通过阻断HIF-1α与Myc的相互作用抑制PD-L1的表达。此外,通过抑制PD-L1在癌症中稳定T细胞活性并抑制增殖和血管生成。目前的工作强调了Britannin的抗肿瘤作用,通过PD-L1抑制提供对癌症治疗发展的见解。
BACKGROUND: Programmed cell death-ligand 1 (PD-L1) is overexpressed in tumor cells, which causes tumor cells to escape T cell killing, and promotes tumor cell survival, cell proliferation, migration, invasion, and angiogenesis.
Britannin is a natural product with anticancer pharmacological effects.
OBJECTIVE: In this work, we studied the anticancer potential of
britannin and explored whether
britannin mediated its effect by inhibiting the expression of PD-L1 in tumor cells.
METHODS: In vitro, the mechanisms underlying the inhibition of PD-L1 expression by
britannin were investigated by MTT assay, homology modeling and molecular docking, RT-PCR, western blotting, co-immunoprecipitation, and immunofluorescence. The changes in tumor killing activity, cell proliferation, cell cycle, migration, invasion, and angiogenesis were analyzed by T cell killing assays, EdU labeling, colony formation, flow cytometry, wound healing, matrigel transwell invasion, and tube formation, respectively. In vivo, the antitumor activity of
britannin was evaluated in the HCT116 cell xenograft model.
RESULTS: Britannin reduced the expression of PD-L1 in tumor cells by inhibiting the synthesis of the PD-L1 protein but did not affect the degradation of the PD-L1 protein. Britannin also inhibited HIF-1α expression through the mTOR/P70S6K/4EBP1 pathway and Myc activation through the Ras/RAF/MEK/ERK pathway. Mechanistically, britannin inhibited the expression of PD-L1 by blocking the interaction between HIF-1α and Myc. In addition, britannin could enhance the activity of cytotoxic T lymphocytes and inhibit tumor cell proliferation and angiogenesis by inhibiting PD-L1. Finally, in vivo observations were confirmed by demonstrating the antitumor activity of britannin in a murine xenograft model.
CONCLUSIONS: Britannin inhibits the expression of PD-L1 by blocking the interaction between HIF-1α and Myc. Moreover, britannin stabilizes T cell activity and inhibits proliferation and angiogenesis by inhibiting PD-L1 in cancer. The current work highlights the anti-tumor effect of britannin, providing insights into the development of cancer therapeutics via PD-L1 inhibition.