The role of dinitrosyliron complexes in cancer etiology

二亚硝基铁络合物在癌症病因学中的作用

• 批准号: 8462478
• 负责人: DOUGLAS D. THOMAS
• 金额: $ 23.79万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8462478
• 关键词: Antineoplastic Agents; Binding; Biochemical; Biological; Biological Availability; Breast; Breast Cancer Cell; Cancer Etiology; Cell Line; Cell physiology; Cells; Chelating Agents; Chemicals; Chemistry; Clinical Trials; Complex; DNA biosynthesis; Data; Development; Diagnostic Neoplasm Staging; Dietary Iron; Dose; Drug Targeting; Electron Spin Resonance Spectroscopy; Enzymes; Epidemiology; Ferritin; Foundations; Free Radicals; Functional disorder; Generations; Goals; Guanylate Cyclase; Harvest; Homeostasis; Human; Hypoxia; Image; Intervention; Iron; Kinetics; Knowledge; Label; Laboratories; Learning; Link; MCF7 cell; Malignant Neoplasms; Measurement; Measures; Mediating; Mediator of activation protein; Metabolism; Methods; Migration Assay; Monitor; Neoplasm Metastasis; Nitric Oxide; Nitric Oxide Donors; Oxidants; Oxidative Stress; Oxygen; Pharmaceutical Preparations; Phenotype; Physiological; Physiology; Pilot Projects; Production; Prognostic Marker; Property; Proteins; Reaction; Reporting; Ribonucleotide Reductase; Risk; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Source; Technology; Testing; Therapeutic; Time; Transferrin Receptor; Translational Repression; base; cancer cell; cancer risk; cancer type; cell growth; cell motility; cell type; chemotherapeutic agent; clinically significant; cytotoxic; cytotoxicity; driving force; electric impedance; indexing; macrophage; malignant breast neoplasm; metal chelator; migration; neoplastic cell; receptor expression; research study; response; theories; tumor; tumor progression; uptake

DESCRIPTION (provided by applicant): There is a significant epidemiologic association between both ferritin-bound stored iron and dietary iron with an increased risk of breast cancer. Iron has been implicated in the initiation and progression of cancer through the generation of mutagenic reactive oxygen and as a component of ribonucleotide reductase, the rate-limiting enzyme in DNA synthesis. For these reasons, iron has emerged as a potential drug target in cancer and the use of iron chelators is currently being evaluated in clinical trials. Nitric oxide (NO) is upregulated in a variety of tumor types, including breast, and is often considered a negative prognostic indicator. This proposal is based on the discovery that when cancer cells are exposed to NO it reacts with free iron in the labile iron pool (LIP). This results in the quantitative conversion of this iron into paramagnetic dinitrosyliron complexes (DNIC). This proposal is aimed at testing the hypothesis that NO-mediated formation of DNIC serves two vital cellular functions: (1) short-term protection against iron-driven oxidative stress and (2) long-term inhibition of cell growth and migration by restricting the bioavailability of labile iron. Although much has been learned pertaining to the chemistry of DNIC assembly and degradation under synthetic laboratory conditions, there is a knowledge gap regarding the biological parameters that favor DNIC metabolism and the consequences of these reactions on tumor cell phenotype. We propose the following aims using breast cancer cells and NO-producing macrophages: Aim 1 is to test the hypothesis that labile iron is a principal target for NO in cancer cells. In Aim 2 we will demonstrate that the cytoprotective properties of NO are a consequence of DNIC formation. Finally, Aim 3 will test the hypothesis that NO suppresses tumor cell migration via iron sequestration. These aims are supported by our preliminary data which demonstrate that breast cancer cells treated with metal chelators recapitulate specific effects of DNIC formation. Methods: Using electron paramagnetic resonance (EPR) imaging we will quantify the amount and measure the kinetics of DNIC formation and disappearance in breast (MCF7, MCF10A, MDA-MB-231, HCC1806) and macrophage (RAW 264.7) cell lines following exogenous (NO-donors) and endogenous (NO producing macrophages) NO exposure. These results will demonstrate the cytoprotective effects of NO against damage induced by chemical oxidants and oxidant-generating chemotherapeutic agents. Lastly, using a label-free real-time cell migration assay we will measure the migratory ability of breast cancer cells in relation to iron in its labile or DNIC form. Significance: Iron is emerging as an important driving force for various types of cancers (including breast), leading to the use of iron chelators as potential treatments. Nitric oxide has also been implicated in various stages of cancer. This proposal will help solidify a new role for NO in cancer by demonstrating unique signaling and phenotypic responses attributable to DNIC formation. This has significance in regard to endogenous NO-producing tumors as well as NO-mediated chemotherapeutics.

描述（由申请人提供）：铁蛋白结合的铁和饮食铁之间存在着显着的流行病学关联，患有乳腺癌的风险增加。铁已经通过产生诱变的活性氧和核糖核苷酸还原酶的成分（DNA合成中的速率限制酶）与癌症的起始和进展有关。由于这些原因，铁已经成为癌症的潜在药物靶标，目前正在临床试验中评估铁螯合剂的使用。一氧化氮（NO）在包括乳房在内的多种肿瘤类型中被上调，通常被认为是阴性的预后指标。该提议基于这样的发现，即当癌细胞暴露于NO时，它会在不稳定的铁池（LIP）中与游离铁反应。这导致该铁的定量转化为顺磁性二硝基铁复合物（DNIC）。该建议旨在检验以下假设：NOT介导的DNIC的形成具有两个重要的细胞功能：（1）针对铁驱动的氧化应激的短期保护，以及（2）长期抑制细胞生长和迁移通过限制不稳定铁的生物可利用性。尽管在合成实验室条件下与DNIC组装和降解的化学有关的知识已经有很多了解，但有关生物学参数有利于DNIC代谢的知识差距以及这些反应对肿瘤细胞表型的后果。我们提出以下目的使用乳腺癌细胞和无产巨噬细胞：目标1是测试一个假设，即不稳定铁是癌细胞中NO的主要目标。在AIM 2中，我们将证明NO的细胞保护特性是DNIC形成的结果。最后，AIM 3将检验以下假设，即不抑制通过铁固存抑制肿瘤细胞的迁移。这些目标得到了我们的初步数据的支持，这些数据表明，用金属螯合剂处理的乳腺癌细胞概括了DNIC形成的特定作用。方法：使用电子顺磁共振（EPR）成像，我们将量化乳房中dNIC形成和消失的数量和测量动力学（MCF7，MCF10A，MDA-MB-231，HCC1806）和巨噬细胞（RAW 264.7）（RAW 264.7）细胞线（无exenos（无deponors）和无生殖器（无生产）。这些结果将证明NO对化学氧化剂和氧化剂产生化学治疗剂造成的损伤的细胞保护作用。最后，使用无标签的实时细胞迁移测定法，我们将测量乳腺癌细胞与铁的不稳定或dnic形式相关的迁移能力。意义：铁成为各种类型癌症（包括乳房）的重要驱动力，导致使用铁螯合剂作为潜在疗法。一氧化氮也与癌症的各个阶段有关。该建议将通过证明归因于DNIC形成的独特信号传导和表型反应来帮助巩固NO在癌症中的新作用。这对于内源性无产肿瘤以及无介导的化学治疗剂具有重要意义。