PO.CL08.01 · 临床研究
靶向CPT-1介导的脂肪酸氧化可使胶质母细胞瘤产生放射增敏
Targeting CPT‑1‑mediated fatty acid oxidation causes radiation sensitization in glioblastoma
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：胶质母细胞瘤（GBM）是成人中最常见的原发性脑肿瘤，尽管接受手术、化疗和放疗，其中位生存期仍不足两年。一个胶质瘤干样细胞（GSC）亚群可在放疗后存活并使肿瘤再生。近期研究表明，GSC高度依赖线粒体脂肪酸氧化（FAO）来产生ATP、再生NAD⁺并维持氧化还原平衡。肉碱棕榈酰转移酶-1（CPT-1）通过将长链脂肪酸转运至线粒体基质，催化FAO的限速步骤。因此，我们假设药理学抑制CPT-1将限制GSC代谢并使GSC对放疗敏感。
方法：将人GBM细胞系U-118和一株患者来源的GSC系（GNS144）用哌克昔林（perhexiline，5 μM）、依托莫昔（etomoxir，10 μM）或溶剂对照处理72 h。随后细胞接受单次0、2、4、6或8 Gy照射。48 h后测定细胞活力。放疗后7-14天进行成球实验，记录球体数目和平均直径。采用免疫印迹评估干细胞标志物CD44、Nestin和Vimentin。所有实验均一式三份进行；采用双因素方差分析（two-way ANOVA）及Tukey事后检验评估统计学显著性（p < 0.05）。
结果：与单纯放疗相比，哌克昔林+放疗和依托莫昔+放疗产生了剂量依赖性的细胞活力下降（p < 0.001）。在4-8 Gy范围内，联合治疗使球体数目减少55-70%（p ≤ 0.005），并使平均球体直径降低30%（p ≤ 0.005）。免疫印迹分析显示，与单纯放疗相比，药物+放疗组中CD44、Nestin和Vimentin表达降低2倍（p < 0.01）。
结论：这些结果提示，用哌克昔林或依托莫昔抑制CPT-1介导的FAO，可在标准和患者来源的GBM模型中增强放疗诱导的细胞死亡、抑制成球能力并下调关键GSC标志物。这些发现值得进一步研究，并提示CPT-1阻断可与当前标准治疗方案相结合，以克服由干细胞驱动的放射抵抗。
查看英文原文 English abstract
Background: Glioblastoma (GBM) is the most common primary brain tumor in adults and has a median survival of less than two years despite surgery, chemotherapy, and radiotherapy. A subpopulation of glioma stem‑like cells (GSCs) survives radiation and repopulates the tumor. Recent studies have shown that GSCs rely heavily on mitochondrial fatty‑acid oxidation (FAO) for ATP production, NAD⁺ regeneration, and redox balance. Carnitine‑palmitoyl‑transferase‑1 (CPT‑1) catalyzes the rate limiting step of FAO by shuttling long‑chain fatty acids into the mitochondrial matrix. We therefore hypothesized that pharmacologic inhibition of CPT‑1 will limit GSC metabolism and sensitize GSCs to radiation.
Methods: Human GBM cell line U‑118 and a patient‑derived GSC line (GNS144) were treated for 72 h with perhexiline (5 µM), etomoxir (10 µM), or vehicle control.Cells then received a single fraction of 0, 2, 4, 6, or 8 Gy. Cell viability was measured 48 h later. Sphere formation assays were performed 7-14 days after radiation; sphere number and mean diameter were recorded. Immunoblotting was performed to evaluate for stem cell markers CD44, Nestin, and Vimentin. All experiments were performed in triplicate; statistical significance was assessed by two‑way ANOVA with Tukey post‑hoc test (p < 0.05).
Results: Perhexiline + radiation and etomoxir + radiation produced a dose dependent decline in cell viability compared with radiation alone (p < 0.001). Combination treatment reduced sphere number by 55-70 % across the 4-8 Gy range (p ≤ 0.005) and lowered mean sphere diameter by 30 % (p ≤ 0.005). Immunoblotting analysis showed a 2‑fold reductions in CD44, Nestin, and Vimentin expression in the drug + radiation arms versus radiation alone (p < 0.01).
Conclusions: These results suggest that inhibition of CPT‑1‑mediated FAO with perhexiline or etomoxir enhances radiation induced cell death, suppresses sphere forming capacity, and downregulates key GSC markers in both standard and patient-derived GBM models. These findings should be investigated further and suggest that CPT‑1 blockade could be integrated with current standard of care regimens to overcome stem cell driven radiation resistance.
利益披露 Disclosure
K. M. Austin, None..
T. Huang, None..
T. Miller, None..
K. B. Pointer, None.