Staab Adrian, Löffler Jürgen, Said Harun M, Katzer Astrid, Beyer Melanie, Polat Bülent, Einsele Hermann, Flentje Michael, Vordermark Dirk
Department of Radiotherapy, University of Wuerzburg, Germany.
Strahlenther Onkol. 2007 Jul;183(7):366-73. doi: 10.1007/s00066-007-1649-6.
The hypoxic accumulation of the transcription factor subunit hypoxia-inducible factor-1alpha (HIF-1alpha), a potential endogenous hypoxia marker and therapeutic target, has recently been shown to strongly depend on glucose availability. The aim of this study was to investigate the underlying mechanism of this effect.
HIF-1alpha protein levels were studied by Western blotting in HT 1080 human fibrosarcoma cells and in a hypoxia-responsive element green fluorescent protein (HRE-GFP) reporter assay in stably transfected HT 1080 cells treated with hypoxia (0.1% O(2), 12 h) and glycolysis inhibitors 2-deoxyglucose (2-DG) or iodoacetate (IAA). HIF-1alpha mRNA expression was quantified via real-time polymerase chain reaction (RT-PCR).
Both inhibitors drastically reduced hypoxic HIF-1alpha accumulation (2-DG + hypoxia 2% mean HIF-1alpha protein level vs. 59% hypoxia alone; IAA + hypoxia 13% mean HIF-1alpha protein level vs. 96% hypoxia alone), an effect not rescued by the addition of pyruvate and confirmed in an HRE-GFP reporter assay in stably transfected HT 1080 cells. RT-PCR under identical conditions showed no effect of glycolysis inhibition on HIF-1alpha mRNA levels, suggesting a translational or posttranslational mechanism.
The effect of glycolysis modulation on the HIF-1alpha levels in tumor cells may provide a novel approach to therapeutically target HIF-1alpha.
转录因子亚基缺氧诱导因子-1α（HIF-1α）是一种潜在的内源性缺氧标志物和治疗靶点，其在缺氧条件下的蓄积最近被证明强烈依赖于葡萄糖的可利用性。本研究旨在探究这种效应的潜在机制。
通过蛋白质免疫印迹法研究HT 1080人纤维肉瘤细胞中HIF-1α蛋白水平，并在稳定转染的HT 1080细胞中进行缺氧反应元件绿色荧光蛋白（HRE-GFP）报告基因检测，这些细胞用缺氧（0.1% O₂，12小时）以及糖酵解抑制剂2-脱氧葡萄糖（2-DG）或碘乙酸盐（IAA）处理。通过实时聚合酶链反应（RT-PCR）对HIF-1α mRNA表达进行定量分析。
两种抑制剂均显著降低了缺氧诱导的HIF-1α蓄积（2-DG + 缺氧组HIF-1α蛋白平均水平为2%，而单纯缺氧组为59%；IAA + 缺氧组HIF-1α蛋白平均水平为13%，而单纯缺氧组为96%），添加丙酮酸并不能挽救这种效应，且在稳定转染的HT 1080细胞的HRE-GFP报告基因检测中得到证实。相同条件下的RT-PCR结果显示，糖酵解抑制对HIF-1α mRNA水平无影响，提示存在翻译或翻译后机制。
糖酵解调节对肿瘤细胞中HIF-1α水平的影响可能为靶向治疗HIF-1α提供一种新方法。
