Signaling and Targeting of 6-Phosphogluconate Dehydrogenase in Human Cancers

人类癌症中 6-磷酸葡萄糖酸脱氢酶的信号传导和靶向

基本信息

批准号：
8630691
负责人：
Jing Chen
金额：
$ 33.52万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-04-15 至 2019-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8630691
关键词：
5&apos -AMP-activated protein kinase 6-phosphogluconate Acetyl-CoA Carboxylase Acetylation Acetylcysteine Anabolism Attenuated B-Cell Acute Lymphoblastic Leukemia Back Binding Bioenergetics Bone Marrow Transplantation Cancer cell line Cell Proliferation Cell Survival Cells Cervical Intraepithelial Neoplasia Clinical Treatment Colorectal Cancer Complex DNA biosynthesis Data Development Enzymes Evaluation H1299 Homeostasis Human In Vitro K-562 Laboratories Link Lysine Malignant Neoplasms Malignant neoplasm of lung Metabolic Metabolic Pathway Metabolism Modeling Mus NADP Normal Cell Nucleotide Biosynthesis Nude Mice Oxidation-Reduction Pathogenesis Pathway interactions Patients Pentosephosphate Pathway Pharmaceutical Preparations Phosphogluconate Dehydrogenase Phosphorylation Phosphorylation Inhibition Production Protein Kinase Inhibitors RNA RNA biosynthesis Reducing Agents Regulation Reporting Resistance Role STK11 gene Signal Transduction Signaling Molecule Testing Tissues Toxic effect Xenograft procedure base cancer cell in vivo inhibitor/antagonist leukemia lipid biosynthesis mimetics mutant next generation novel protein kinase inhibitor public health relevance ribulose 5-phosphate small hairpin RNA small molecule therapeutic target thyroid neoplasm tumor tumor growth tumor metabolism

项目摘要

Abstract: How cancer cells coordinate anabolic biosynthesis and redox homeostasis remains largely unknown. In normal cells, 6-phosphogluconate dehydrogenase (6PGD), an enzyme in the oxidative pentose phosphate pathway (PPP), converts 6-phosphogluconate (6-PG) to ribulose 5-phosphate (Ru-5-P) and produces NADPH. Upregulated 6PGD activity has been reported in several cancer tissues including colorectal cancers, cervical intraepithelial neoplasia and thyroid tumors, as well as leukemia (our unpublished data). However, how 6PGD is activated in human cancers and whether 6PGD activity is important in pathogenesis and tumor development remain unknown. We found that acetylation at K76 and K294 enhances 6PGD activation and is commonly observed in diverse human cancer cells. Stable knockdown of 6PGD in cancer cells results in reduced oxidative PPP flux and RNA/DNA biosynthesis. Surprisingly, 6PGD knockdown also causes decreased NADPH/NADP+ ratio, suggesting an important role for 6PGD in NADPH production that cannot be compensated by other NADPH-producing enzymes. Moreover, cancer cells with 6PGD knockdown show elevated ROS levels and aberrant biosynthesis, leading to reduced cell proliferation and tumor growth in xenograft nude mice. We next screened and identified Physcion as a novel, selective small molecule 6PGD inhibitor. Treatment with Physcion or its derivative S3 effectively inhibits cell proliferation in diverse human cancer cells with no off-target effect. Physcion and S3 also effectively inhibit cell viability and proliferation of primary leukemia cells from human patients with minimal toxicity. Furthermore, S3 significantly reduces tumor growth in xenograft nude mice subcutaneously injected with human H1299 lung cancer or K562 leukemia cells with minimal toxicity in vivo. Thus, we hypothesize that lysine acetylation enhances 6PGD activation, which promotes cancer cell proliferation and tumor growth; 6PGD thus represents a novel anti-cancer target in clinical treatment. Intriguingly, we also found that knockdown of 6PGD results in decreased intracellular levels of Ru-5-P (6PGD product), leading to activation of AMP-activated protein kinase (AMPK), which subsequently inhibits acetyl-CoA carboxylase 1 (ACC1) and consequently lipogenesis. Thus, in addition to the well-established connection between PPP and nucleotide biosynthesis, 6PGD provides a novel link between PPP, AMPK signaling and lipogenesis, which, along with the surprisingly crucial role for 6PGD in NADPH production and redox homeostasis, is important for cancer metabolism and tumor growth. We will test these hypotheses using human lung cancer and leukemias (CML, AML and B-ALL) as platforms. Three Specific Aims were proposed (1) To examine whether lysine acetylation is important for 6PGD activation and promotion of cancer cell metabolism and tumor growth; (2) To explore how 6PGD links PPP, AMPK signaling and lipogenesis to coordinate with redox regulation in promoting cancer cell metabolism and tumor growth; and (3) To validate 6PGD as an anti-leukemia target in treatment of human leukemia cells in vitro and in vivo using 6PGD small molecule inhibitors developed in our laboratory.

抽象的：癌细胞如何协调合成代谢生物合成和氧化还原稳态仍然在很大程度上未知。正常细胞，6-磷酸葡萄糖酸脱氢酶（6PGD），一种氧化五戊糖磷酸途径中的酶（PPP），将6-磷酸葡萄糖酸（6-PG）转换为5-磷酸盐（RU-5-P）并产生NADPH。在包括结直肠癌，宫颈的几种癌症组织中，已经报道了上调的6pGD活性上皮内肿瘤和甲状腺肿瘤以及白血病（我们未发表的数据）。但是，如何6点在人类癌症中激活，以及6pGD活性在发病机理和肿瘤发育中是否重要仍然未知。我们发现K76和K294处的乙酰化增强了6pgd的激活，通常是在各种人类癌细胞中观察到。癌细胞中6pGD的稳定敲低导致氧化降低 PPP通量和RNA/DNA生物合成。出乎意料的是，6pgd敲低也导致NADPH/NADP+下降比率，表明6pgd在NADPH生产中起重要作用产生NADPH的酶。此外，具有6pgd敲低的癌细胞显示ROS水平升高，异常生物合成，导致异种移植小鼠的细胞增殖和肿瘤生长减少。我们接下来筛选并鉴定出物理为一种新颖的选择性小分子6PGD抑制剂。用物理治疗或其导数S3有效地抑制了不同人类癌细胞中的细胞增殖，没有脱靶效应。 Physcion和S3还有效地抑制了人类原发性白血病细胞的细胞活力和增殖毒性最小的患者。此外，S3显着降低了异种移植小鼠的肿瘤生长皮下注射人类H1299肺癌或体内毒性最小的K562白血病细胞。因此，我们假设赖氨酸乙酰化增强了6PGD激活，从而促进癌细胞增殖和肿瘤生长；因此，6PGD代表了临床治疗中的新型抗癌靶标。有趣的是，我们也是如此发现6pgd的敲低导致细胞内RU-5-P（6pgd产物）的降低，导致 AMP激活蛋白激酶（AMPK）的激活，随后抑制乙酰辅酶A羧化酶1 （ACC1），因此是脂肪生成。因此，除了PPP和PPP之间的联系之外核苷酸生物合成，6PGD提供了PPP，AMPK信号传导和脂肪形成之间的新联系，该联系是除了在NADPH生产和氧化还原稳态中，6pGD的至关重要的作用非常重要，对于癌症代谢和肿瘤生长。我们将使用人肺癌和白血病检验这些假设（CML，AML和B-all）作为平台。提出了三个具体目标（1）来检查赖氨酸是否乙酰化对于6pGD激活和促进癌细胞代谢和肿瘤生长很重要。（2）至探索6pGD如何将PPP，AMPK信号传导和脂肪形成链接到促进的氧化还原调节癌细胞代谢和肿瘤生长；（3）验证6PGD作为治疗的抗白血病靶标在我们的实验室中开发的6pGD小分子抑制剂的体外和体内人类白血病细胞。