Triple-negative breast cancer (TNBC) is highly metastatic and lethal. Due to a lack of druggable targets for this disease, there are no effective therapies in the clinic. We used TNBC cells and xenografted mice as models to explore triptonide-mediated inhibition of TNBC metastasis and tumor growth. Colony formation assay was used to quantify the tumorigenesis of TNBC cells. Wound-healing and cell trans-well assays were utilized to measure cell migration and invasion. Tube formation assay was applied to access tumor cell-mediated vasculogenic mimicry. Western blot, quantitative-PCR, immunofluorescence imaging, and immunohistochemical staining were used to measure the expression levels of various tumorigenic genes in TNBC cells. Here, we showed that triptonide, a small molecule from the traditional Chinese medicinal herb Tripterygium wilfordii Hook F, potently inhibited TNBC cell migration, invasion, and vasculogenic mimicry, and effectively suppressed TNBC tumor growth and lung metastasis in xenografted mice with no observable toxicity. Molecular mechanistic studies revealed that triptonide strongly triggered the degradation of master epithelial-mesenchymal transition (EMT)-inducing protein Twist1 through the lysosomal system and reduced Notch1 expression and NF-κB phosphorylation, which consequently diminished the expression of pro-metastatic and angiogenic genes N-cadherin, VE-cadherin, and vascular endothelial cell growth factor receptor 2 (VEGFR2). Triptonide effectively suppressed TNBC cell tumorigenesis, vasculogenic mimicry, and strongly inhibited the metastasis of TNBC via degradation of Twist1 and Notch1 oncoproteins, downregulation of metastatic and angiogenic gene expression, and reduction of NF-κB signaling pathway. Our findings provide a new strategy for treating highly lethal TNBC and offer a potential new drug candidate for combatting this aggressive disease.

中文翻译：

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雷普酮通过同时降解 Twist1 和 Notch1 癌蛋白有效抑制三阴性乳腺癌转移

三阴性乳腺癌 (TNBC) 具有高度转移性和致死性。由于缺乏针对这种疾病的药物靶点，临床上没有有效的治疗方法。我们使用 TNBC 细胞和异种移植小鼠作为模型来探索雷公藤介导的 TNBC 转移和肿瘤生长的抑制作用。集落形成测定用于量化 TNBC 细胞的肿瘤发生。伤口愈合和细胞跨孔测定用于测量细胞迁移和侵袭。管形成测定被应用于访问肿瘤细胞介导的血管生成模拟。Western印迹、定量PCR、免疫荧光成像和免疫组织化学染色用于测量TNBC细胞中各种致瘤基因的表达水平。在这里，我们展示了雷公藤 来自中草药雷公藤Hook F的小分子，有效抑制TNBC细胞迁移、侵袭和血管生成模拟，并有效抑制异种移植小鼠的TNBC肿瘤生长和肺转移，且无明显毒性。分子机制研究表明，雷公藤酮通过溶酶体系统强烈触发主上皮间质转化（EMT）诱导蛋白 Twist1 的降解，并降低 Notch1 表达和 NF-κB 磷酸化，从而降低前转移和血管生成基因 N 的表达-钙粘蛋白、VE-钙粘蛋白和血管内皮细胞生长因子受体 2 (VEGFR2)。Triptonide 有效抑制 TNBC 细胞肿瘤发生、血管生成拟态、并通过降解 Twist1 和 Notch1 癌蛋白、下调转移性和血管生成基因表达以及减少 NF-κB 信号通路强烈抑制 TNBC 的转移。我们的研究结果为治疗高度致命的 TNBC 提供了一种新策略，并为对抗这种侵袭性疾病提供了一种潜在的新候选药物。