PO.TB03.03 · 肿瘤生物学
染色体外环状DNA介导的NOSIP扩增驱动肝细胞癌中OXPHOS依赖的转移
Extrachromosomal circular DNA-mediated NOSIP amplification drives OXPHOS-dependent metastasis in hepatocellular carcinoma
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：远处转移是肝细胞癌（HCC）癌症相关死亡的主要原因，然而赋予转移能力的分子决定因素仍不明确。染色体外环状DNA（eccDNA）是一种能够扩增癌基因并促进肿瘤演化的非染色体遗传元件，近来受到关注。然而，HCC中eccDNA所携带基因的功能图谱及其在转移进展中的机制作用仍未明确。
方法：使用Circle-seq分析配对的原发性和转移性HCC组织，以鉴定转移相关的eccDNA。通过整合的多组学分析并利用公共数据集验证，进一步评估候选驱动因素。在稳定过表达或敲低NOSIP的HCC细胞系中进行功能研究，随后进行迁移和侵袭实验。通过免疫沉淀-质谱鉴定蛋白质相互作用因子。使用Seahorse XF分析评估细胞生物能量功能，并在体外和体内进一步检验所鉴定相互作用的机制相关性。
结果：含NOSIP的eccDNA在转移性HCC样本中显著富集，NOSIP表达升高与不良总生存相关。NOSIP过表达显著增强细胞迁移和侵袭，而敲低则抑制这些表型。蛋白质组学分析鉴定出丙酮酸脱氢酶E1亚基β（PDHB）为NOSIP的主要结合伙伴。NOSIP上调增加了耗氧率并激活了氧化磷酸化（OXPHOS），提示线粒体代谢活性增强。这些发现表明，eccDNA介导的NOSIP扩增通过参与PDHB依赖的线粒体代谢重编程来促进转移特性。
结论：总之，本研究鉴定出含NOSIP的eccDNA为HCC中OXPHOS依赖性转移适应的一个先前未被认识的分子驱动因素。所提出的eccDNA-NOSIP-PDHB轴揭示了非染色体遗传扩增与线粒体代谢重塑之间的机制联系，为晚期HCC的治疗干预提供了潜在的代谢易感性。
查看英文原文 English abstract
Background: Distant metastasis is the major cause of cancer-related mortality in hepatocellular carcinoma (HCC), yet the molecular determinants that confer metastatic competence remain poorly defined. Extrachromosomal circular DNA (eccDNA), a non-chromosomal genetic element capable of amplifying oncogenes and promoting tumor evolution, has recently gained attention. However, the functional landscape of eccDNA-carried genes in HCC and their mechanistic roles in metastatic progression remain undefined.
Methods: Paired primary and metastatic HCC tissues were analyzed using Circle-seq to identify metastasis-associated eccDNAs. Candidate drivers were further evaluated through integrated multi-omics analyses and validation using public datasets. Functional studies were performed in HCC cell lines with stable NOSIP overexpression or knockdown, followed by migration and invasion assays. Protein interactors were identified by immunoprecipitation-mass spectrometry. Cellular bioenergetic function was evaluated using Seahorse XF analysis, and the mechanistic relevance of identified interactions was further examined in vitro and in vivo.
Results: NOSIP-containing eccDNA was markedly enriched in metastatic HCC samples, and elevated NOSIP expression correlated with poor overall survival. NOSIP overexpression significantly enhanced cell migration and invasion, while knockdown suppressed these phenotypes. Proteomic profiling identified pyruvate dehydrogenase E1 subunit beta (PDHB) as a major NOSIP-binding partner. NOSIP upregulation increased oxygen consumption rate and activated oxidative phosphorylation (OXPHOS), indicating enhanced mitochondrial metabolic activity. These findings demonstrate that eccDNA-mediated NOSIP amplification promotes metastatic traits by engaging PDHB-dependent mitochondrial metabolic reprogramming.
Conclusion: In conclusion, this study identifies NOSIP-containing eccDNA as a previously unrecognized molecular driver of OXPHOS-dependent metastatic adaptation in HCC. The proposed eccDNA-NOSIP-PDHB axis reveals a mechanistic link between non-chromosomal genetic amplification and mitochondrial metabolic remodeling, offering a potential metabolic vulnerability for therapeutic intervention in advanced HCC.
利益披露 Disclosure
X. Lin, None..
Y. Luo, None..
Y. Pan, None..
G. Deng, None..
Y. Lin, None..
Y. Zhang, None..
J. Wang, None..
S. Fang, None.