脂肪酸氧化抑制剂Etomoxir增强神经胶质瘤放射治疗敏感性的实验研究

Etomoxir enhances the radio-sensitivity of glioblastoma cells

目的 初步研究神经胶质瘤的放射治疗（放疗）抵抗效应中脂肪酸代谢变化,以期为提高放疗效果提供理论依据.方法 用60 Gy剂量照射体外培养胶质瘤细胞GBM1、GBM2和GBM3,分析比较存活下来的放疗抗性细胞（Treatment-resistant glioblastoma clones,TRGC）和未经放疗处理的肿瘤细胞（treatment-sensitive glioblastoma clones,TSGC）之间AMPK、Akt和NAD＋等能量代谢差异,并用基因芯片差异分析系统比较两者之间代谢调节基因的表达变化,根据脂肪酸代谢相关基因表达差异,选用脂肪酸氧化抑制剂Etomoxir抑制GBM1、GBM2和GBM3脂肪酸代谢后的放疗效果.结果 经过60Gy剂量照射后的GBM1、GBM2和GBM3分别在照射结束后的第181、66和233天形成放疗抗性克隆TRGC,与TSGC细胞克隆相比,生成的活化AMPK、Akt和NAD＋明显增多,脂肪酸代谢调节基因TXNIP、EGR1、ALDH3A2、PLD3、SLC38A1和OSBPL8等基因明显增高.与单独用4 Gy剂量放疗处理的TRGC克隆只有极少数细胞凋亡相比,用脂肪酸氧化抑制剂Etomoxir抑制脂肪酸代谢后再用4Gy低剂量放疗处理的TRGC出现大量细胞凋亡,即使培养4周后形成的新克隆小且稀疏.结论 脂肪酸氧化代谢与胶质瘤细胞的放疗抵抗有关,抑制脂肪酸氧化代谢后明显增加胶质瘤细胞的放射治疗效果.

Objective To explore the change of fatty acids metabolism in the radiation-resistance of glioblastoma cells and to provide theoretical rationales for improved radiotherapy.Methods After treating GBM1,GBM2 and GBM3 with 60 Gy irradiation in vitro,survival radiation resistant cells （TRGC） were compared with untreated sensitive tumor cells （TSGC） with regards to the contents of AMPK,Akt and NAD ＋.The expression of metabolic regulation genes was measured with gene chip analysis system.Then TRGC were treated with 4 Gy irradiation after suppressing the oxidative metabolism of fatty acid with Etomoxir.Results GBM1,GBM2 and GBM3 re-grew on Days 181,66 and 233 days respectively after 60 Gy irradiation.TRGC generated more AMPK,Akt and NAD ＋ than TSGC.Metabolic regulation genes TXNIP,EGR1,ALDH3A2,PLD3,SLC38A1 and OSBPL8 increased obviously in TRGC.Compared to low apoptosis in TRGC with 4 Gy irradiation only,there was a higher rate of apoptosis in TRGC with 4 Gy irradiation and Etomoxir.New clones were small and sparse even after 4-week growth.Conclusions Oxidative metabolism of fatty acid is associated with radiotherapy resistance of glioma cells.And the efficacy of radiotherapy of glioma cells significantly increases after suppression of oxidative metabolism of fatty acid.