背景:LappaolF(LAF),来自ArctiumlappaLinné(菊科)的天然木酚素,通过诱导细胞周期停滞抑制肿瘤细胞生长。然而,其潜在的抗癌机制仍不清楚。
目的:LAF对Hippo-Yes相关蛋白(YAP)信号通路的影响,在癌症进展中起着重要作用,在这项研究中进行了探索。
方法:宫颈(HeLa),结直肠(SW480),用不同浓度和不同持续时间的LAF处理乳腺癌(MDA-MB-231)和前列腺癌(PC3)细胞系.携带结肠异种移植物的BALB/c裸鼠静脉注射载体,LAF(10或20mg/kg)或紫杉醇(10mg/kg)持续15天。使用转录组测序分析YAP的表达和核定位,定量PCR,蛋白质印迹和免疫荧光。
结果:LAF抑制了HeLa的增殖,MDA-MB-231,SW480和PC3细胞(IC50值分别为41.5,26.0,45.3和42.9μmol/L,分别,在72小时),这伴随着YAP及其下游靶基因在mRNA和蛋白质水平上的表达的显著下调。14-3-3σ的表达式,一种导致YAP细胞质滞留和降解的蛋白质,显著增加,导致YAP核定位减少。用小干扰RNA敲除14-3-3σ部分阻断LAF诱导的YAP抑制和抗增殖作用。在结肠异种移植物中,用LAF治疗导致YAP表达减少,增加肿瘤细胞凋亡和肿瘤生长抑制。
结论:LAF被证明是YAP的抑制剂。它通过在转录和翻译后水平抑制YAP发挥抗癌活性。
BACKGROUND: Lappaol F (LAF), a natural lignan from Arctium lappa Linné (Asteraceae), inhibits tumour cell growth by inducing cell cycle arrest. However, its underlying anticancer mechanism remains unclear.
OBJECTIVE: The effects of LAF on the Hippo-Yes-associated protein (YAP) signalling pathway, which plays an important role in cancer progression, were explored in this study.
METHODS: Cervical (HeLa), colorectal (SW480), breast (MDA-MB-231) and prostate (PC3) cancer cell lines were treated with LAF at different concentrations and different durations. BALB/c nude mice bearing colon xenografts were intravenously injected with vehicle, LAF (10 or 20 mg/kg) or paclitaxel (10 mg/kg) for 15 days. The expression and nuclear localisation of YAP were analysed using transcriptome sequencing, quantitative PCR, western blotting and immunofluorescence.
RESULTS: LAF suppressed the proliferation of HeLa, MDA-MB-231, SW480 and PC3 cells (IC50 values of 41.5, 26.0, 45.3 and 42.9 μmol/L, respectively, at 72 h), and this was accompanied by significant downregulation in the expression of YAP and its downstream target genes at both the mRNA and protein levels. The expression of 14-3-3σ, a protein that causes YAP cytoplasmic retention and degradation, was remarkably increased, resulting in a decrease in YAP nuclear localisation. Knockdown of 14-3-3σ with small interfering RNA partially blocked LAF-induced YAP inhibition and anti-proliferation effects. In colon xenografts, treatment with LAF led to reduced YAP expression, increased tumour cell apoptosis and tumour growth inhibition.
CONCLUSIONS: LAF was shown to be an inhibitor of YAP. It exerts anticancer activity by inhibiting YAP at the transcriptional and post-translational levels.