目的:巴豆化,基于巴豆酰辅酶A的非酶蛋白翻译修饰,影响不同的生物过程,比如精子发生,组织损伤,炎症,和神经精神疾病。巴豆化显示肝细胞癌(HCC)减少,但机制仍然未知。在这项研究中,我们的目的是描述戊二酰辅酶A脱氢酶(GCDH)在肿瘤抑制中的作用。
方法:使用包含40、248和17对样品的三个队列来评估GCDH表达水平与HCC临床特征以及抗PD-1反应之间的联系。皮下异种移植,原位异种移植物,Trp53Δhep/Δhep;MYC-以及Ctnnboe;采用METoe驱动的小鼠模型来验证GCDH对HCC抑制的作用。
结果:GCDH耗竭促进HCC生长和转移,而它的过度表达逆转了这些过程。当GCDH将戊二酰辅酶A转化为巴豆酰辅酶A以增加巴豆酰化水平时,我们进行了赖氨酸crotonylome分析,并鉴定了戊糖磷酸途径(PPP)和糖酵解相关蛋白PGD,TKT,和ALDOC作为GCDH诱导的巴豆化靶标。巴豆酰结合的靶标显示出控制其酶活性的变构效应,导致核糖5-磷酸和乳酸的产生减少,进一步限制Warburg效应。PPP封锁也刺激了过氧化,与衰老调节剂协同诱导GCDHhigh细胞衰老。这些细胞通过衰老相关分泌细胞表型(SASP)诱导免疫细胞浸润,从而形成抗肿瘤免疫微环境。同时,GCDHlow人群对抗程序性细胞死亡蛋白1(PD-1)治疗敏感.
结论:GCDH通过巴豆化诱导的PPP抑制和糖酵解抑制HCC进展,导致肝癌细胞衰老。衰老细胞通过SASP进一步塑造抗肿瘤微环境。GCDHlow群体易受抗PD-1治疗的影响,因为在GCDHlow群体中表现出更多的PD-1+CD8+T细胞。
■GCDH是肝脏的有利预后指标,肺,和肾癌。此外,大部分GCDH耗竭诱导的毒性代谢物来自肝脏,在当地积累,无法穿越血脑屏障.因此,研究GCDH与肝癌的相关性将有助于发现肝细胞癌的发生发展,其中超过70%的患者GCDH下调>2倍。鉴于GCDHlow和GCDHhighHCC人群可以根据血清葡萄糖和氨水平进行区分,值得根据GCDH的表达水平评估衰老和免疫治疗策略的疗效.
OBJECTIVE: Crotonylation, a crotonyl-CoA-based non-enzymatic protein translational modification, affects diverse biological processes, such as spermatogenesis, tissue injury, inflammation, and neuropsychiatric diseases. Crotonylation is decreased in hepatocellular carcinomas (HCCs), but the mechanism remains unknown. In this study, we aim to describe the role of glutaryl-CoA dehydrogenase (GCDH) in tumor suppression.
METHODS: Three cohorts containing 40, 248 and 17 pairs of samples were used to evaluate the link between GCDH expression levels and clinical characteristics of HCC, as well as responses to anti-programmed cell death protein 1 (PD-1) treatment. Subcutaneous xenograft, orthotopic xenograft, Trp53Δhep/Δhep; MYC- and Ctnnboe;METoe-driven mouse models were adopted to validate the effects of GCDH on HCC suppression.
RESULTS: GCDH depletion promoted HCC growth and metastasis, whereas its overexpression reversed these processes. As GCDH converts glutaryl-CoA to crotonyl-CoA to increase crotonylation levels, we performed lysine crotonylome analysis and identified the pentose phosphate pathway (PPP) and glycolysis-related proteins PGD, TKT, and ALDOC as GCDH-induced crotonylation targets. Crotonyl-bound targets showed allosteric effects that controlled their enzymatic activities, leading to decreases in ribose 5-phosphate and lactate production, further limiting the Warburg effect. PPP blockade also stimulated peroxidation, synergizing with senescent modulators to induce senescence in GCDHhigh cells. These cells induced the infiltration of immune cells by the SASP (senescence-associated secretory cell phenotype) to shape an anti-tumor immune microenvironment. Meanwhile, the GCDHlow population was sensitized to anti-PD-1 therapy.
CONCLUSIONS: GCDH inhibits HCC progression via crotonylation-induced suppression of the PPP and glycolysis, resulting in HCC cell senescence. The senescent cell further shapes an anti-tumor microenvironment via the SASP. The GCDHlow population is responsive to anti-PD-1 therapy because of the increased presence of PD-1+CD8+ T cells.
UNASSIGNED: Glutaryl-CoA dehydrogenase (GCDH) is a favorable prognostic indicator in liver, lung, and renal cancers. In addition, most GCDH depletion-induced toxic metabolites originate from the liver, accumulate locally, and cannot cross the blood-brain barrier. Herein, we show that GCDH inhibits hepatocellular carcinoma (HCC) progression via crotonylation-induced suppression of the pentose phosphate pathway and glycolysis, resulting in HCC cell senescence. We also found that more PD-1+CD8+ T cells are present in the GCDHlow population, who are thus more responsive to anti-PD-1 therapy. Given that the GCDHlow and GCDHhigh HCC population can be distinguished based on serum glucose and ammonia levels, it will be worthwhile to evaluate the curative effects of pro-senescent and immune-therapeutic strategies based on the expression levels of GCDH.