Role of Diabetes in Development of Renal Cell Carcinoma

糖尿病在肾细胞癌发展中的作用

• 批准号: 8245579
• 负责人: Samy Lewiz Habib
• 金额: --
• 依托单位: SOUTH TEXAS VETERANS HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8245579
• 关键词: 1-Phosphatidylinositol 3-Kinase; 8-Oxo-2' -Deoxyguanosine; 8-hydroxyguanosine; Active Sites; Acute; Agonist; Alleles; American; Animals; Biological Markers; Blood specimen; Breeding; Cancer Etiology; Cancer Patient; Cells; Cessation of life; Chronic; Colon; Conventional (Clear Cell) Renal Cell Carcinoma; DNA; DNA Damage; DNA Repair; DNA Repair Enzymes; DNA glycosylase; Data; Development; Diabetes Mellitus; Diagnosis; Diagnostic Neoplasm Staging; Down-Regulation; Endometrium; Enzymes; Epithelial Cells; Family member; Fibroblasts; Frequencies; General Population; Generations; Genes; Glucose; Goals; High Pressure Liquid Chromatography; Human; Hyperglycemia; Incidence; Kidney; Kidney Neoplasms; Knockout Mice; Liver; Loss of Heterozygosity; Magnetic Resonance Imaging; Malignant Neoplasms; Measures; Messenger RNA; Military Personnel; Mus; Mutagenesis; Mutation; NADPH Oxidase; OGG1 gene; Organ; Pancreas; Pathway interactions; Patients; Persons; Phosphorylation; Population; Production; Proteins; Raptors; Rattus; Reactive Oxygen Species; Recording of previous events; Regulation; Renal Cell Carcinoma; Renal carcinoma; Reporter Genes; Risk; Role; Sampling; Screening for cancer; Screening procedure; Severities; Shuttle Vectors; Signal Transduction; Sirolimus; Small Interfering RNA; Solid Neoplasm; Specimen; Staining method; Stains; Testing; Texas; Time; Tissues; Transfection; Tuberous Sclerosis; Tuberous sclerosis protein complex; Tubular formation; Tumor Burden; Tumor Suppressor Genes; Tumor Suppressor Proteins; Tumor stage; United States; Urologic Cancer; Veterans; Western Blotting; carcinogenesis; diabetic; diabetic patient; diabetic rat; enzyme activity; high risk; human FRAP1 protein; human TSC2 protein; loss of function; loss of function mutation; mRNA Expression; mortality; mouse model; non-diabetic; oxidative DNA damage; promoter; public health relevance; research study; tumor; tumorigenesis

DESCRIPTION (provided by applicant): Rationale: Patients with diabetes are at higher risk than the general population of developing cancer of the urinary tract, liver, pancreas, colon, endometrium and kidney. Diabetes and hyperglycemia are associated with enhanced production of reactive oxygen species and induce DNA damage by several mechanisms. 8-Oxodeoxyguanine (8-oxodG) a major form of oxidative DNA damage has been implicated in early carcinogenesis. The DNA repair enzyme that recognizes and excises 8-oxodG is 8- oxoG-DNA glycosylase (OGG1). Deficiency in OGG1 has important functional consequences, compromising the ability of cells to repair DNA. Indeed, loss of heterozygosity at the OGG1 allele was found in human renal clear cell carcinoma (RCC) identifying loss of OGG1 function as a possible contributor to tumorigenesis in the kidney. Our preliminary data show that 8-oxodG levels are increased in kidney tissue of diabetic animal and human. In addition, we found that mutation in Ser326, the active site of OGG1 enzyme is increased in DNA blood samples from diabetic patients. One of the tumor suppressor genes involved in renal carcinogenesis is tuberous sclerosis gene (TSC2), which encodes tumor suppressor protein, tuberin. Eker rats harboring mutations in TSC2 develop spontaneous renal tumors at a very high incidence. We showed also that loss of function of the tumor suppressor gene, tuberous sclerosis complex 2 (TSC2), which encodes the protein tuberin, is associated with loss of function and mutations of OGG1 gene and accumulation of significant amounts of 8-oxodG in animal and human kidney tissues. Certain agonists activate PI-3 kinase and Akt, which stimulate tuberin phosphorylation resulting in its inactivation. Our preliminary studies show that incubation of rat renal proximal tubular cells (the cell origin of renal cell carcinoma) in high glucose results in increased reactive oxygen species (ROS) enhanced tuberin phosphorylation and decreased OGG1 expression. We also find that tuberin phosphorylation is increased in kidneys of diabetic rat. This is associated with increased levels of 8-oxodG. We have screened 500 kidney tumors from RCC patients and found that 25% of them has a history with diabetes. The mechanism(s) by which patients with diabetes are predisposed to cancer are not known. Hypothesis: We hypothesize that the increased production of ROS in diabetic subjects phosphorylates and inactivates tuberin, activates mTORC1 and/or mTORC2 resulting in downregulation of the DNA repair enzyme 8-oxoG-DNA glycosylase (OGG1) and accumulation of 8-oxodG. 8-OxodG enhances mutagenesis and predisposes the kidney and other organs to cancer. To explore our hypothesis we propose the following specific aims: SPECIFIC AIM 1: To determine the mechanism by which high glucose down-regulates OGG1 in proximal tubular cells, the cell origin of renal cell carcinoma. SPECIFIC AIM 2: To explore the effect of diabetes on the rate of development and severity as well as on the mutation frequency of renal cell carcinoma in the TSC-2 heterozygous rat and OGG1-/- mouse models. SPECIFIC AIM 3: To determine the levels of oxidative DNA damage (8-oxodG), OGG1 (protein, activity and mRNA) expression, the incidence of Ser326 mutation in OGG1, and levels of Akt, tuberin, S6K phosphorylation and downstream signals of mTOR in kidney tissue from patients with diabetes, patients with kidney cancer as well as patients with kidney cancer and diabetes. PUBLIC HEALTH RELEVANCE: The renal cell carcinoma (RCC) is one of the most lethal kidney cancers and is the sixth leading cause of cancer deaths. Every year approximately 40,000 Americans are diagnosed with RCC including military personnel, their family members, and U.S. Veteran population. More than 12,000 deaths in the United States are caused by RCC. Patients with diabetes are at higher risk than the general population of developing certain malignancies including kidney. Cancer contributes approximately 13% to mortality in diabetic patients. In Texas, an estimated of 1.9 million persons have been diagnosed with diabetes. The increasing the incidence of diabetes in our population will increase the risk of solid tumors including RCC. Our goal is to identify the mechanism by which diabetes accelerate tumor formation in kidney and other organs and validate 8-oxodG and OGG1 mutation(s) as new biomarkers for screening the diabetic subjects for early detection of cancer.

描述（由申请人提供）： 理由：糖尿病患者患尿路癌、肝癌、胰腺癌、结肠癌、子宫内膜癌和肾癌的风险高于一般人群。糖尿病和高血糖与活性氧产生的增加有关，并通过多种机制诱导 DNA 损伤。 8-氧化脱氧鸟嘌呤 (8-oxodG) 是 DNA 氧化损伤的主要形式，与早期癌症发生有关。识别并切除 8-oxoG 的 DNA 修复酶是 8-oxoG-DNA 糖基化酶 (OGG1)。 OGG1 缺乏会产生重要的功能后果，损害细胞修复 DNA 的能力。事实上，在人肾透明细胞癌 (RCC) 中发现了 OGG1 等位基因杂合性的丧失，确定 OGG1 功能的丧失可能是肾脏肿瘤发生的一个因素。我们的初步数据表明，糖尿病动物和人类的肾组织中 8-oxodG 水平升高。此外，我们发现糖尿病患者的DNA血液样本中OGG1酶的活性位点Ser326的突变增加。参与肾癌发生的抑癌基因之一是结节性硬化症基因（TSC2），它编码抑癌蛋白马铃薯蛋白。携带 TSC2 突变的 Eker 大鼠自发性肾肿瘤的发生率非常高。我们还发现，编码马铃薯蛋白的肿瘤抑制基因结节性硬化症复合物 2 (TSC2) 的功能丧失与 OGG1 基因的功能丧失和突变以及动物和动物体内大量 8-oxodG 的积累有关。人类肾脏组织。某些激动剂会激活 PI-3 激酶和 Akt，从而刺激马铃薯蛋白磷酸化，导致其失活。我们的初步研究表明，在高葡萄糖条件下培养大鼠肾近端肾小管细胞（肾细胞癌的细胞起源）会导致活性氧 (ROS) 增加，增强马铃薯蛋白磷酸化并降低 OGG1 表达。我们还发现糖尿病大鼠肾脏中的马铃薯球蛋白磷酸化增加。这与 8-oxodG 水平升高有关。我们筛查了500名肾癌患者的肾肿瘤，发现其中25%有糖尿病史。糖尿病患者易患癌症的机制尚不清楚。假设：我们假设糖尿病受试者中 ROS 产生的增加会磷酸化和灭活马铃薯蛋白，激活 mTORC1 和/或 mTORC2，导致 DNA 修复酶 8-oxoG-DNA 糖基化酶 (OGG1) 的下调和 8-oxodG 的积累。 8-OxodG 增强诱变并使肾脏和其他器官易患癌症。为了探索我们的假设，我们提出以下具体目标： 具体目标 1：确定高葡萄糖下调近端肾小管细胞（肾细胞癌的细胞起源）中 OGG1 的机制。具体目标2：探讨糖尿病对TSC-2杂合子大鼠和OGG1-/-小鼠模型中肾细胞癌的发生率、严重程度以及突变频率的影响。具体目标 3：确定氧化 DNA 损伤 (8-oxodG) 的水平、OGG1（蛋白质、活性和 mRNA）表达、OGG1 中 Ser326 突变的发生率以及 Akt、马铃薯蛋白、S6K 磷酸化和 mTOR 下游信号的水平存在于糖尿病患者、肾癌患者以及肾癌和糖尿病患者的肾组织中。 公共卫生相关性： 肾细胞癌（RCC）是最致命的肾癌之一，也是癌症死亡的第六大原因。每年约有 40,000 名美国人被诊断患有 RCC，其中包括军人、他们的家人和美国退伍军人。美国有超过 12,000 人死于 RCC。糖尿病患者比一般人群患某些恶性肿瘤（包括肾脏疾病）的风险更高。癌症约占糖尿病患者死亡率的 13%。在德克萨斯州，估计有 190 万人被诊断患有糖尿病。我国人口中糖尿病发病率的增加将增加患实体瘤（包括肾细胞癌）的风险。我们的目标是确定糖尿病加速肾脏和其他器官肿瘤形成的机制，并验证 8-oxodG 和 OGG1 突变作为新的生物标志物，用于筛选糖尿病受试者以早期发现癌症。