三阴性乳腺癌( TNBC)表现出高水平的上皮间质转化( EMT)和程序性死亡配体1( PD-L1)表达，促进免疫逃逸和转移。巴西利因是从番红花中提取的一种天然化合物，已被证明在各种癌细胞中具有抗炎，抗增殖和诱导凋亡的作用。在这里，我们用MCF-7和MDA-MB-231细胞作为模型，研究巴西利因对乳腺癌细胞EMT和PD-L1表达的影响以及其相关的分子机制。由于AKT，NF-κB和GSK3β / β-catenin信号被报道为免疫逃逸和转移的重要机制，因此在我们的研究中也发现了巴西利因对这些信号通路的影响。首先，在不同浓度的情况下，对乳腺癌细胞进行了巴西利因处理，以研究细胞活力，凋亡和凋亡蛋白。然后，用无毒浓度的巴西利因处理乳腺癌细胞，研究其对EMT和PD-L1蛋白表达的影响，分别使用MTT，流式细胞术，Western blot和伤口愈合分析。我们发现，巴西利因通过诱导凋亡减少细胞活力，产生抗癌效应，同时还通过抑制AKT，NF-κB和GSK3β / β-catenin的磷酸化来降低EMT和PD-L1的水平。此外，通过抑制MMP-9和MMP-2的活化，降低了迁移能力。综上所述，巴西利因通过抑制EMT，PD-L1和转移的发展，可能可以延缓癌症的进展，提示它可能是乳腺癌患者的一种潜在治疗选择，尤其是存在高水平EMT和PD-L1的患者。 版权所有©2023。Elsevier BV出版。

Triple-negative breast cancer (TNBC) exhibits high levels of Epithelial-mesenchymal transition (EMT) and Programmed death ligand 1 (PD-L1) expression, which promotes immune escape and metastasis. Brazilein is a natural compound extracted from Caesalpinia sappan L., and has been demonstrated to be an anti-inflammatory anti- proliferative and apoptosis-inducer in various cancer cells. Here, we investigated the effect of brazilein on EMT and PD-L1 expression in breast cancer cells and its related molecular mechanisms using MCF-7 and MDA-MB-231 cells as a model. Since the AKT, NF-κB, and GSK3β/β-catenin signaling were reported to be important mechanisms in immune escape and metastasis, the effect of brazilein on these signaling pathways were also found out in our study. Firstly, brazilein was treated on breast cancer cells at various concentrations to study cell viability, apoptosis, and apoptosis proteins. Then, breast cancer cells were treated with non-toxic concentrations of brazilein to study its influence on EMT and expression of PD-L1 protein using MTT, flow cytometry, western blot, and wound healing analysis, respectively. We found that brazilein exerts an anti-cancer effect by reducing cell viability via induction of apoptosis, while it also downregulated EMT and PD-L1 through suppression of phosphorylation of AKT, NF-κB, and GSK3β/β-catenin. Moreover, the migration ability was diminished by inhibiting the activation of MMP-9 and MMP-2. Taken together, brazilein might delay cancer progression through inhibition of EMT, PD-L1, and metastasis suggesting it might be a potential therapeutic option in breast cancer patients having a high level of EMT and PD-L1.Copyright © 2023. Published by Elsevier B.V.