Palayoor Sanjeewani T, Tofilon Philip J, Coleman C Norman
Radiation Oncology Branch, Center for Cancer Research and the Molecular Radiation Therapeutics Branch, Division of Cancer Treatment and Diagnosis, National Cancer Institute, NIH, Bethesda, Maryland, 20892-1002, USA.
Clin Cancer Res. 2003 Aug 1;9(8):3150-7.
Hypoxia-inducible factors HIF-1alpha and HIF-2alpha are considered to be potential targets for antineoplastic therapy because they regulate the expression of genes that contribute to tumor cell survival, aggressiveness, and angiogenesis. Nonsteroidal anti-inflammatory drugs (NSAIDs) have gained considerable interest as anticancer agents because of their cytotoxic and antiangiogenic properties. The aim of this study was to investigate whether NSAIDs inhibit HIFs and HIF-regulated gene expression in prostate cancer cells.
PC3 and DU-145 cells were treated with ibuprofen (Ibu) and other NSAIDs under normoxic and hypoxic (95% N(2), 5% CO(2); <10 ppm O(2)) conditions. The effect of NSAIDs on HIF proteins was analyzed by Western blot analysis. HIF-regulated proteins, vascular endothelial growth factor (VEGF) and glucose transporter-1 (Glut-1), were analyzed by ELISA and Western blot analysis, respectively.
Exposure of PC3 and DU-145 cells to hypoxic condition up-regulated HIF-1alpha and HIF-2alpha proteins. Treatment with Ibu under normoxic and hypoxic conditions reduced the level of HIF-1alpha and HIF-2alpha. Ibu-mediated down-regulation of HIFs was associated with down-regulation of HIF-regulated proteins VEGF and Glut-1 in cells exposed to hypoxia. Other nonspecific NSAIDs, diclofenac and ketorolac, also inhibited HIF-1alpha and HIF-2alpha. The reduction in HIFs was observed in PC3 cells that expressed cyclooxygenase-2 (COX-2) protein as well as in DU-145 cells, which did not express COX-2 protein. COX-2-specific inhibitor NS-398 did not inhibit HIF-1alpha or VEGF and GLUT-1.
These data indicate that one of the effects of NSAIDs is to reduce HIF protein levels. The inhibition of HIFs by NSAIDs was COX-2 independent.
缺氧诱导因子HIF-1α和HIF-2α被认为是抗肿瘤治疗的潜在靶点，因为它们调节有助于肿瘤细胞存活、侵袭性和血管生成的基因表达。非甾体抗炎药（NSAIDs）因其细胞毒性和抗血管生成特性而作为抗癌药物备受关注。本研究的目的是调查NSAIDs是否抑制前列腺癌细胞中的HIFs和HIF调节的基因表达。
在常氧和低氧（95% N₂，5% CO₂；<10 ppm O₂）条件下，用布洛芬（Ibu）和其他NSAIDs处理PC3和DU-145细胞。通过蛋白质印迹分析NSAIDs对HIF蛋白的影响。分别通过酶联免疫吸附测定（ELISA）和蛋白质印迹分析HIF调节的蛋白血管内皮生长因子（VEGF）和葡萄糖转运蛋白1（Glut-1）。
将PC3和DU-145细胞暴露于低氧条件下会上调HIF-1α和HIF-2α蛋白。在常氧和低氧条件下用Ibu处理可降低HIF-1α和HIF-2α的水平。Ibu介导的HIFs下调与低氧条件下细胞中HIF调节的蛋白VEGF和Glut-1的下调相关。其他非特异性NSAIDs双氯芬酸和酮咯酸也抑制HIF-1α和HIF-2α。在表达环氧合酶-2（COX-2）蛋白的PC3细胞以及不表达COX-2蛋白的DU-145细胞中均观察到HIFs的减少。COX-2特异性抑制剂NS-398不抑制HIF-1α或VEGF及GLUT-1。
这些数据表明NSAIDs的作用之一是降低HIF蛋白水平。NSAIDs对HIFs的抑制与COX-2无关。
