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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

白血病的治疗方法以化疗为主，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为白血病患者建立更无创的治疗方法。我们报道称，活性氧（ROS）是绿茶多酚（-）-表没食子儿茶素-3-没食子酸酯（EGCG）诱导细胞凋亡的关键介质。 EGCG 快速诱导 MPO 阳性白血病细胞系以及 AML 新鲜样本凋亡，但不诱导 MPO 阴性白血病细胞系凋亡。将 MPO 阳性白血病细胞与 MPO 特异性抑制剂 4-氨基苯甲酸酰肼 (ABAH) 和血红素生物合成抑制剂琥珀酰丙酮 (ScAc) 预孵育，添加 EGCG 后可抑制 ROS 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 MPO cDNA 和空载体转染至 MPO 阴性 K562 细胞中。与对照细胞相比，MPO 转染细胞增强了 MPO 活性和 ROS 产生，并使 EGCG 抗性 K562 细胞对 ROS 产生剂诱导的细胞凋亡敏感。此外，表达 K562 (K562/H502A) 细胞的无酶活性 MPO 突变体无法对 EGCG 做出反应，这表明 MPO 对于确定对 EGCG 诱导的氧化应激的敏感性很重要。此外，值得注意的是，在 EGCG 刺激后，APF 和 HPF 负载的髓系白血病细胞的荧光强度均显着增加，表明 EGCG 在 MPO 阳性白血病细胞中产生剧毒的 ROS。综上所述，这些观察结果表明，通过H_2O_2/MPO/卤化物系统产生的羟自由基等高毒性ROS可诱导细胞凋亡，并且此类ROS可能是MPO阳性白血病细胞氧化应激诱导细胞凋亡的直接介质。 Affimetrix 基因芯片的基因表达谱显示 HIF-1α 及其下游基因（RTP801、EGR-1、BNIP3 和 VEGF）上调，表明 HIF-1α 途径对于 ROS 介导的细胞凋亡非常重要。较少的