Ma Xiao, Zhang Baojian, Yin Xuezhe, Yang ShiPeng, Lin Zhenhua, Yang Yang, Zhou Xianchun
Central Laboratory, Yanbian University Hospital, Yanji, 133000, PR China.
Key Laboratory of Tumor Pathobiology, Yanbian University, State Ethnic Affairs Commission, Yanji, 133000, PR China.
Breast Cancer Res. 2025 May 12;27(1):74. doi: 10.1186/s13058-025-02039-0.
In tumors rich in adipose tissue, angiogenesis is a critical factor in promoting cancer cell metastasis. However, the connection between angiogenesis and the mechanisms driving adipose metabolic remodeling in breast cancer (BC) remains insufficiently understood. This research seeks to explore whether and how CPT1A, a crucial rate-limiting enzyme in fatty acid oxidation (FAO), supports angiogenesis through metabolic pathways in BC.
First, cell functional assays and animal models were employed to elucidate the pro-carcinogenic effects of CPT1A on BC and its role in metabolic alterations. Following this, the reciprocal regulatory relationship between CPT1A and HIF-1α was elucidated using transcriptomic studies, ubiquitination analysis, and dual-luciferase assays. Matrigel tube formation assays, vasculogenic mimicry assays, and chick chorioallantoic membrane (CAM) assays were utilized to evaluate the effect of CPT1A on the pro-angiogenic properties of BC. Subsequently, untargeted metabolomics was employed to identify specific metabolic changes in supernatants with and without CPT1A expression and verified by functional recovery experiments. Finally, the prognostic significance of CPT1A and the vascular marker VEGF in BC tissues was evaluated using tissue microarrays and public databases.
CPT1A overexpression significantly enhanced cell proliferation, motility, and angiogenesis via activating the FAO metabolic pathway, as demonstrated by both in vivo and in vitro experiments. Mechanistically, CPT1A regulates the ubiquitination level of hypoxia-inducible factor-1α (HIF-1α), which directly binds to the CPT1A promoter. Mutations at the 63-74 and 434-445 regions significantly reduced CPT1A promoter activity, indicating that these sites are critical for its transcriptional regulation. Ultimately, this interaction creates a reinforcing feedback loop between CPT1A and HIF-1α. Subsequently, this feedback loop alters changes in extracellular L-ascorbic acid (LAA) levels. Interestingly, LAA affects ROS homeostasis through the Nrf2/NQO1 pathway, specifically influencing angiogenesis in BC and HUVECs, while having no significant effect on their proliferation or EMT process. Moreover, increased expression levels of CPT1A and vascular endothelial growth factor (VEGF) were significantly associated with lymph node metastasis and adverse outcomes in BC patients.
The CPT1A/HIF-1α positive feedback loop critically regulates angiogenesis through activation of the Nrf2/NQO1 pathway, modulated by LAA. These findings highlight CPT1A and VEGF as promising therapeutic targets and prognostic biomarkers for angiogenesis in BC.
在富含脂肪组织的肿瘤中，血管生成是促进癌细胞转移的关键因素。然而，血管生成与驱动乳腺癌（BC）脂肪代谢重塑机制之间的联系仍未得到充分理解。本研究旨在探讨脂肪酸氧化（FAO）中的关键限速酶CPT1A是否以及如何通过BC中的代谢途径支持血管生成。
首先，采用细胞功能试验和动物模型来阐明CPT1A对BC的促癌作用及其在代谢改变中的作用。在此之后，使用转录组学研究、泛素化分析和双荧光素酶试验来阐明CPT1A与HIF-1α之间的相互调节关系。利用基质胶管形成试验、血管生成拟态试验和鸡胚绒毛尿囊膜（CAM）试验来评估CPT1A对BC促血管生成特性的影响。随后，采用非靶向代谢组学来鉴定有无CPT1A表达的上清液中的特定代谢变化，并通过功能恢复实验进行验证。最后，使用组织芯片和公共数据库评估CPT1A和血管标志物VEGF在BC组织中的预后意义。
体内和体外实验均表明，CPT1A过表达通过激活FAO代谢途径显著增强细胞增殖、迁移和血管生成。从机制上讲，CPT1A调节缺氧诱导因子-1α（HIF-1α）的泛素化水平，HIF-1α直接与CPT1A启动子结合。63-74和434-445区域的突变显著降低CPT1A启动子活性，表明这些位点对其转录调控至关重要。最终，这种相互作用在CPT1A和HIF-1α之间形成了一个增强的反馈环。随后，这个反馈环改变细胞外L-抗坏血酸（LAA）水平的变化。有趣的是，LAA通过Nrf2/NQO1途径影响ROS稳态，特别影响BC和人脐静脉内皮细胞（HUVECs）中的血管生成，而对它们的增殖或EMT过程没有显著影响。此外，CPT1A和血管内皮生长因子（VEGF）表达水平的升高与BC患者的淋巴结转移和不良预后显著相关。
CPT1A/HIF-1α正反馈环通过激活由LAA调节的Nrf2/NQO1途径关键地调节血管生成。这些发现突出了CPT1A和VEGF作为BC血管生成中有前景的治疗靶点和预后生物标志物。
