First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan 250022, China.
Department of Oncology, The Affiliated Qingdao Hiser hospital of Qingdao University (Qingdao Hospital of Traditional Chinese Medicine), Qingdao 266071, China.
Phytomedicine. 2024 Jul 25;130:155746. doi: 10.1016/j.phymed.2024.155746. Epub 2024 May 15.
Triple-negative breast cancer (TNBC) is a category of breast cancer characterized with high molecular heterogeneity. Owing to the lack of effective therapeutic strategies, patients with TNBC have a poor prognosis. Paris saponin VII (PSⅦ), a steroidal saponin extracted from the rhizome of Trichillium tschonoskii Maxim, exhibits excellent anti-cancer activity in a variety of solid tumors. However, the role and potential mechanism of PSⅦ against TNBC remain unexplored.
This study aimed to elucidate the therapeutic effects of PSⅦ against TNBC and explore the potential mechanism of action.
We combined the analysis of public single-cell sequencing data with weighted gene co-expression network analysis (WGCNA) to identity differentially expressed genes (DEGs) that distinguished malignant and normal epithelial cells in TNBC. Subsequently, the biological features of DEGs in TNBC were evaluated. Gene set enrichment analysis (GSEA) was used to define potential pathways associated with the DEGs. The pharmacological activity of PSⅦ for TNBC was evidenced via in vitro and in vivo experiments, and molecular docking, molecular dynamics (MD), surface plasmon resonance (SPR) assay and western blotting were employed to confirm the relative mechanisms.
Single-cell sequencing and WGCNA revealed STMN1 as a pivotal biomarker of TNBC. STMN1 overexpression in TNBC was associated with poor patient prognosis. GSEA revealed a significant accumulation of STMN1 within the MAPK signaling pathway. Furthermore, In vitro experiments showed that PSⅦ showed significantly suppressive actions on the proliferation, migration and invasion abilities for TNBC cells, while inducing apoptosis. Molecular docking, MD analysis and SPR assay indicated a robust interaction between PSⅦ and the MEK protein. Western blotting revealed that PSⅦ may inhibit tumor progression by suppressing the phosphorylation of MEK1/2 and the downstream phosphorylation of ERK1/2 and STMN1. Intraperitoneal injection of PSⅦ (10 mg/kg) notably reduced tumor growth by 71.26 % in a 4T1 xenograft model.
In our study, the systems biology method was used to identify potential therapeutic targets for TNBC. In vitro and in vivo experiments demonstrated PSⅦ suppresses cancer progression by targeting the MEK/ERK/STMN1 signaling axis. For the first time, the inhibition of STMN1 phosphorylation has been indicated as a possible mechanism for the anticancer effects of PSⅦ. These results emphasize the potential value of PSⅦ as a promising anti-cancer drug candidate for further development in the field of TNBC therapeutics.
三阴性乳腺癌（TNBC）是一种具有高度分子异质性的乳腺癌类别。由于缺乏有效的治疗策略，TNBC 患者的预后较差。从 Trichillium tschonoskii Maxim 根茎中提取的甾体皂甙 Paris saponin VII（PSⅦ）在多种实体瘤中表现出优异的抗癌活性。然而，PSⅦ 对 TNBC 的作用和潜在机制仍未得到探索。
本研究旨在阐明 PSⅦ 对 TNBC 的治疗作用，并探讨其潜在的作用机制。
我们结合公共单细胞测序数据的分析和加权基因共表达网络分析（WGCNA），鉴定出区分 TNBC 中恶性和正常上皮细胞的差异表达基因（DEGs）。随后，评估了 TNBC 中 DEGs 的生物学特征。基因集富集分析（GSEA）用于定义与 DEGs 相关的潜在途径。通过体外和体内实验以及分子对接、分子动力学（MD）、表面等离子体共振（SPR）测定和 Western blot 证实 PSⅦ 对 TNBC 的药理活性，以确认相对机制。
单细胞测序和 WGCNA 显示 STMN1 是 TNBC 的关键生物标志物。TNBC 中 STMN1 的过表达与患者预后不良相关。GSEA 显示 STMN1 在 MAPK 信号通路中显著富集。此外，体外实验表明 PSⅦ 对 TNBC 细胞的增殖、迁移和侵袭能力具有显著的抑制作用，同时诱导细胞凋亡。分子对接、MD 分析和 SPR 测定表明 PSⅦ 与 MEK 蛋白之间存在强大的相互作用。Western blot 显示 PSⅦ 可能通过抑制 MEK1/2 的磷酸化以及 ERK1/2 和 STMN1 的下游磷酸化来抑制肿瘤进展。在 4T1 异种移植模型中，腹腔注射 PSⅦ（10mg/kg）可使肿瘤生长显著减少 71.26%。
在本研究中，系统生物学方法被用于鉴定 TNBC 的潜在治疗靶点。体外和体内实验表明 PSⅦ 通过靶向 MEK/ERK/STMN1 信号通路抑制癌症进展。首次表明抑制 STMN1 磷酸化可能是 PSⅦ 抗癌作用的一种可能机制。这些结果强调了 PSⅦ 作为 TNBC 治疗领域有前途的抗癌药物候选物的潜在价值。
