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Establishment of new molecular-targeted therapy for leukemia mediated through HIF-1 regulation by ROS

ROS介导的HIF-1调控白血病新分子靶向治疗的建立

基本信息

批准号：
17591010
负责人：
KIZAKI Masahiro
金额：
$ 2.24万
依托单位：
KEIO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17591010/
关键词：
leukemia molecular target HIF-1 reactive oxygen species transcription factor apoptosis natural product cell cycle

项目摘要

The therapeutic approach to leukemia is based on chemotherapy, but the side effects of the drugs used and various complications are sometimes fatal. Recently, molecular-targeted therapy is pay attention in the clinical setting ; therefore, we have sought out new agents to establish the more non-invasive therapy for the patients with leukemiaWe have reported that reactive oxygen species (ROS) are key mediators of apoptosis induced by a green tea polyphenol, (-)-epigallocatechin-3-gallate (EGCG). EGCG rapidly induced apoptosis in MPO-positive, but not MPO-negative leukemia cell lines as well as fresh samples from AML. Pre-incubation of MPO-positive leukemic cells with the MPO-specific inhibitor, 4-aminobenzoic acid hydrazide (ABAH), and the heme biosynthesis inhibitor, succinylacetone (ScAc), resulted in inhibition of the ROS production and induction of apoptosis following addition of EGCG. To investigate the role of MPO in EGCG-induced apoptosis, we transfected the full length MPO cDNA … More and empty vector into MPO-negative K562 cells. In contrast to control cells, MPO transfected cells enhanced MPO activity and ROS production, and sensitized EGCG-resistant K562 cells to apoptosis induced by ROS-producing agents. In addition, an enzymatically inactive MPO mutant expressing K562 (K562/H502A) cells could not respond to EGCG, suggesting that MPO is important for determining the sensitivity to EGCG-induced oxidative stress. Further, it is noteworthy that the fluorescence intensity of both APF-and HPF-loaded myeloid leukemic cells significantly increased upon stimulation with EGCG suggesting that EGCG generated highly toxic ROS in MPO-positive leukemic cells. Taken together, these observations indicate that highly toxic ROS such as hydroxyl radical generated via the H_2O_2/MPO/halide system induce apoptosis, and that such ROS may be the direct mediators of oxidative stress-induced apoptosis in MPO-positive leukemic cells. Gene expression profiling with Affimetrix gene chips demonstrated HIF-1α and its down-stream genes (RTP801,EGR-1,BNIP3, and VEGF), that were up-regulated, suggesting that HIF-1α pathways will be important for ROS-mediated apoptosis. Less

白血病的治疗方法是以化疗为基础的，但所用药物的副作用和各种并发症有时是致命的。近年来，分子靶向治疗在临床上受到重视，因此，我们寻找新的药物来建立更无创的治疗白血病患者的方法。据报道，活性氧(ROS)是绿茶多酚(-)-表没食子儿茶素没食子酸酯(EGCG)诱导细胞凋亡的关键介质。EGCG能迅速诱导MPO阳性、MPO阴性白血病细胞株和AML新鲜标本的凋亡。用MPO特异性抑制剂4-氨基苯甲酸肼(ABAH)和血红素生物合成抑制剂琥珀酰丙酮(SCAC)预先孵育MPO阳性的白血病细胞，可抑制加入EGCG后ROS的产生，并诱导细胞凋亡。为了研究MPO在EGCG诱导的细胞凋亡中的作用，我们将全长的MPO基因…更多空载体入MPO阴性的K562细胞。与对照组相比，MPO转染组细胞MPO活性增强，ROS生成增加，并使耐EGCG的K562细胞对ROS产生剂诱导的细胞凋亡敏感。此外，表达K562(K562/H502a)细胞的MPO突变体对EGCG没有反应，这表明MPO在决定对EGCG诱导的氧化应激的敏感性方面起着重要作用。此外，值得注意的是，在EGCG刺激下，APF和HPF负载的髓系白血病细胞的荧光强度都显著增加，这表明EGCG在MPO阳性的白血病细胞中产生了高度毒性的ROS。综上所述，这些观察结果表明，通过H_2O_2/MPO/卤化物系统产生的高毒性ROS(如羟基自由基)可诱导细胞凋亡，这种ROS可能是氧化应激诱导MPO阳性白血病细胞凋亡的直接介质。用Affimetrix基因芯片进行基因表达谱分析发现，HIF-1α及其下游基因(RTP801、EGR-1、BNIP3和血管内皮生长因子)表达上调，提示HIF-1α通路在ROS介导的细胞凋亡中具有重要作用。较少