背景:脱氢莫司内酯(Dehy),一种来自雪莲的天然倍半萜内酯,在治疗癌症和胃肠道疾病方面表现出显著的疗效。然而,其抗胃癌(GC)作用尚不清楚。
目的:我们的研究旨在阐明Dehy的抗GC作用及其可能的机制。
方法:用MTT评估抗GC效果,菌落形成,伤口愈合和transwell侵袭分析。通过膜联蛋白V-FITC/PI结合实验检测细胞凋亡率。网络药理学分析和XF底物氧化应激测试探讨了潜在的机制和改变的代谢表型。测量生脂酶表达和中性脂池以评估细胞脂质合成和储存。生物层干涉和分子对接研究了Dehy的直接目标。透射电镜和MDC染色观察自噬体,而自噬通量通过mRFP-GFP-LC3转染检测。组织微阵列证实了ACLY的临床意义。采用患者来源的异种移植物(PDX)模型来检测Dehy的临床治疗潜力。
结果:Dehy在体外和体内均显著抑制GC进展。机械上,Dehy下调脂肪生成酶ACLY,从而减少脂肪酸合成和脂质保留。此外,IKKβ被确定为Dehy的直接靶标。Dehy抑制IKKβ的磷酸化,促进ACLY的泛素化和降解,从而导致脂质消耗。随后,GC细胞启动自噬以补充丢失的脂质,而Dehy通过下调LAMP1和LAMP2表达来阻碍这种细胞保护机制,破坏溶酶体膜功能,最终导致细胞凋亡。此外,Dehy在GC临床治疗中表现出潜力,因为它增强了5-氟尿嘧啶在PDX模型中的功效。
结论:我们的工作确定Dehy是抑制异常脂质代谢的理想药物,并强调了其对保护性自噬的抑制作用,提示Dehy作为GC新型治疗药物的未来发展。
BACKGROUND: Dehydrocostus lactone (Dehy), a natural sesquiterpene lactone from Saussurea lappa Clarke, displays remarkable efficacy in treating cancer and gastrointestinal disorders. However, its anti-gastric cancer (GC) effect remains poorly understood.
OBJECTIVE: Our study aimed to elucidate the anti-GC effect of Dehy and its putative mechanism.
METHODS: The anti-GC effect was assessed with MTT, colony formation, wound healing and transwell invasion assays. Cell apoptosis rate was detected by Annexin V-FITC/PI binding assay. Network pharmacology analysis and XF substrate oxidation stress test explored the underlying mechanism and altered metabolic phenotype. Lipogenic enzyme expressions and neutral lipid pool were measured to evaluate cellular lipid synthesis and storage. Biolayer interferometry and molecular docking investigated the direct target of Dehy. Autophagosomes were observed by transmission electron microscopy and MDC staining, while the autophagic flux was detected by mRFP-GFP-LC3 transfection. The clinical significance of
ACLY was confirmed by tissue microarrays. Patient-derived xenograft (PDX) models were adopted to detect the clinical therapeutic potential of Dehy.
RESULTS: Dehy prominently suppressed GC progression both in vitro and in vivo. Mechanistically, Dehy down-regulated the lipogenic enzyme
ACLY, thereby reducing fatty acid synthesis and lipid reservation. Moreover, IKKβ was identified as the direct target of Dehy. Dehy inhibited the phosphorylation of IKKβ, promoting the ubiquitination and degradation of
ACLY, thereby resulting in lipid depletion. Subsequently, GC cells initiated autophagy to replenish the missing lipids, whereas Dehy impeded this cytoprotective mechanism by down-regulating LAMP1 and LAMP2 expressions, which disrupted lysosomal membrane functions, ultimately leading to apoptosis. Additionally, Dehy exhibited potential in GC clinical therapy as it enhanced the efficacy of 5-Fluorouracil in PDX models.
CONCLUSIONS: Our work identified Dehy as a desirable agent for blunting abnormal lipid metabolism and highlighted its inhibitory effect on protective autophagy, suggesting the future development of Dehy as a novel therapeutic drug for GC.