Timosaponin AIII (Timo AIII) is a natural steroidal saponin isolated from the traditional Chinese herb Anemarrhena asphodeloides Bge with proved effectiveness in the treatment of numerous cancers. However, whether Timo AIII suppresses tumor angiogenesis remains unclear. In the present study, we investigated the antiangiogenesis effects of Timo AIII and the underlying mechanisms in human umbilical vein endothelial cells (HUVECs) in vitro and zebrafish embryos in vivo. We showed that treatment with Timo AIII (0.5-2 µM) partially disrupted the intersegmental vessels (ISVs) and subintestinal vessels (SIVs) growth in transgenic zebrafish Tg(fli-1a: EGFP)y1. Timo AIII (0.5-4 µM) dose-dependently inhibited VEGF-induced proliferation, migration, invasion, and tube formation of HUVECs, but these inhibitory effects were not due to its cytotoxicity. We further demonstrated that Timo AIII treatment significantly suppressed the expression of VEGF receptor (VEGFR) and the phosphorylation of Akt, MEK1/2, and ERK1/2 in HUVECs. Timo AIII treatment also significantly inhibited VEGF-triggered phosphorylation of VEGFR2, Akt, and ERK1/2 in HUVECs. Moreover, we conducted RNA-Seq and analyzed the transcriptome changes in both HUVECs and zebrafish embryos following Timo AIII treatment. The coexpression network analysis results showed that various biological processes and signaling pathways were enriched including angiogenesis, cell motility, cell adhesion, protein serine/threonine kinase activity, transmembrane signaling receptor activity, growth factor activity, etc., which was consistent with the antiangiogenesis effects of Timo AIII in HUVECs and zebrafish embryos. We conclude that the antiangiogenesis effect of Timo AIII is mediated through VEGF/PI3K/Akt/MAPK signaling cascade; Timo AIII potentially exerts antiangiogenesis effect in cancer treatment.

中文翻译：

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timosaponin AIII对HUVECs体外和斑马鱼胚胎的体内抗血管生成作用。

Timosaponin AIII（Timo AIII）是从传统中草药Anemarrhena asphodeloides Bge中分离得到的天然甾体皂苷，已被证明可有效治疗多种癌症。但是，Timo AIII是否抑制肿瘤血管生成尚不清楚。在本研究中，我们研究了Timo AIII的抗血管生成作用及其在体外人脐静脉内皮细胞（HUVEC）和体内斑马鱼胚胎中的潜在机制。我们发现，用Timo AIII（0.5-2 µM）处理可部分破坏转基因斑马鱼Tg（fli-1a：EGFP）y1中的节间血管（ISV）和肠下血管（SIVs）生长。Timo AIII（0.5-4 µM）剂量依赖性地抑制VEGF诱导的HUVEC增殖，迁移，侵袭和管形成，但这些抑制作用并不是由于其细胞毒性。我们进一步证明，Timo AIII处理可显着抑制HUVEC中VEGF受体（VEGFR）的表达以及Akt，MEK1 / 2和ERK1 / 2的磷酸化。Timo AIII处理还可显着抑制HUVEC中VEGF触发的VEGFR2，Akt和ERK1 / 2的磷酸化。此外，我们进行了RNA-Seq并分析了Timo AIII处理后HUVEC和斑马鱼胚胎中转录组的变化。共表达网络分析结果表明，丰富的各种生物学过程和信号通路包括血管生成，细胞运动，细胞粘附，蛋白丝氨酸/苏氨酸激酶活性，跨膜信号受体活性，生长因子活性等，与抗血管生成作用相一致。 HUVEC和斑马鱼胚胎中Timo AIII的表达。我们得出结论，Timo AIII的抗血管生成作用是通过VEGF / PI3K / Akt / MAPK信号级联介导的。Timo AIII在癌症治疗中可能发挥抗血管生成作用。