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：
8838743
负责人：
Jing Chen
金额：
$ 32.96万
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/8838743
关键词：
5&apos -AMP-activated protein kinase 6-phosphogluconate Acetyl-CoA Carboxylase Acetylation 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 Health 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 ribulose 5-phosphate small hairpin RNA small molecule therapeutic target thyroid neoplasm tumor tumor growth tumor metabolism

项目摘要

DESCRIPTION (provided by applicant): 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tissues including colorectal cancers, cervical intraepithelial neoplasia and thyroid tumors, as well as leukemia (our unpublished data).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-taret effect. Physcion and S3 also effectively inhibit cell viability and proliferation of primary leukema 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.

描述（由申请人提供）：癌细胞如何协调合成代谢生物合成和氧化还原稳态仍然很大未知。在正常细胞中，6-磷酸葡萄糖酸脱氢酶（6PGD），氧化五肽磷酸途径（PPP）中的酶，将6-磷酸葡萄糖酸酯（6-PG）转换为5-磷酸盐（RU-5-P）并产生NADPH。已经报道了几种癌症组织中上调的6pGD活性，包括结直肠癌，宫颈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，如何在人类癌症中激活6pGD，以及6pGD活性在发病机理和肿瘤发育中是否重要。我们发现，K76和K294处的乙酰化增强了6PGD激活，通常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PPP通量和RNA/DNA生物合成减少。令人惊讶的是，6pGD敲低还会导致NADPH/NADP+比率降低，这表明6pgd在NADPH产量中起重要作用，而其他产生NADPH产生的酶不能补偿。此外，具有6pGD敲低的癌细胞显示ROS水平升高和异常生物合成，导致异种移植裸鼠的细胞增殖和肿瘤生长降低。接下来，我们筛选并确定了物理为一种新型的选择性小分子6PGD抑制剂。物理或其衍生物S3的治疗有效地抑制了不同人类癌细胞中的细胞增殖，没有含量外影响。 Physcion和S3还有效地抑制了来自最小毒性的人类患者的原代白血病细胞的细胞活力和增殖。此外，S3可显着降低皮下注射人类H1299肺癌的异种移植裸鼠的肿瘤生长或体内毒性最小的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，我们还发现6pGD的敲低导致细胞内水平的RU-5-P（6pGD产物）降低，从而导致AMP激活的蛋白激酶（AMPK）激活，随后抑制了乙酰基-COA羧化酶1（ACC1），并因此抑制了脂肪生成。因此，除了PPP与核苷酸生物合成之间建立了良好的联系外，6pGD还提供了PPP，AMPK信号传导和脂肪生成之间的新联系，这与6pgd在NADPH生产中至关重要的至关重要的作用以及氧化还原稳态的重要作用非常重要。我们将使用人类肺癌和白血病（CML，AML和B-all）作为平台检验这些假设。提出了三个具体目的（1）来检查赖氨酸乙酰化对于6pGD激活和促进癌细胞代谢和肿瘤生长是否重要；（2）探索6pGD如何将PPP，AMPK信号传导和脂肪形成联系起来与氧化还原调节促进癌细胞代谢和肿瘤生长的协调；（3）使用6pgd小分子抑制剂在我们的实验室中开发的6pGD小分子抑制剂在体外和体内验证6PGD作为抗白血病靶标。