Biochemical Mechanisms of Se Anticancer Activity in Lung

描述(由申请人提供)： 当以超营养水平服用时，这种营养基本元素Se也可以化学预防前列腺癌、肺癌和其他几种主要的人类癌症。Se化合物抗癌作用的复杂生化机制(S)尚不清楚，但它们依赖于Se代谢以及多个步骤的氧化还原调节和抗氧化。以前不切实际，现在可以通过结合新的分子图谱工具的力量来探索这种复杂性。通过代谢组学编辑的转录分析(META)来指导靶向蛋白质组学，我们最近发现了控制细胞生长和迁移的硒暴露的肺癌细胞代谢和调控途径的关键变化。这些初步结果导致了我们目前的假设：(A)Se的主要作用位点(S)涉及关键的氧化还原敏感蛋白的共价修饰(S)，包括硫氧还蛋白还原酶(TrxR)和核因子：B；(B)它们导致的功能障碍导致细胞死亡和抗转移。在这里，我们建议将该方法扩展到具有不同转移潜能的人小细胞肺癌细胞，以在RAG1缺失小鼠模型中进行体内验证。我们的具体目标是：目标1：确定选定的人肺癌细胞系对不同硒形式处理后的生化途径与表型变化之间的关系。代谢组学数据将用于识别与生长、凋亡和转移潜力(运动性、趋化性和粘附性)相关的代谢途径；目标2：获得处理细胞的全球和重点基因表达谱，以便与从目标1获得的代谢谱相关联。使用META，将根据目标1的实际代谢变化对基因表达谱进行优先排序，以揭示Se对调节途径和关键靶蛋白的作用；目标3：结合免疫化学和蛋白质组学分析验证细胞系统中的关键工作假说。[潜在的关键蛋白靶点TrxR、NF：B和IKK2]将通过将它们的功能与修饰状态联系起来进行验证；目标4：在RAG缺失的小鼠模型中验证Se在体内对肺癌细胞转移的作用。重点将放在涉及趋化因子SDF-1及其受体CXCR4的转移上，CXCR4由NF：B-TrxR途径调节。目标小鼠组织和血液对硒治疗的反应中的转移和分子特征的改变将与AIMS 1-3的基于细胞的分子特征相关，用于体内验证和正在进行的人类患者研究。这项工作有望加速肺癌化学预防、肿瘤诊断和抗癌疗效的机械性生物标志物的开发。公共卫生相关性营养必需元素硒(Se)已被证明在超营养水平上对前列腺癌、肺癌和其他癌症具有抗癌特性。这种活性的确切性质目前尚不清楚，但与硒的新陈代谢有关，以及它如何降低癌细胞在过度代谢所产生的氧化损伤中存活的能力。在这里，我们建议使用最先进的“代谢组学”和其他“组学”工具，通过细胞培养和小鼠模型来确定硒在肺癌中作用的生化基础。这项工作有望加速肺癌化学预防、肿瘤检测和抗癌治疗的更灵敏诊断的发展。

DESCRIPTION (provided by applicant): The nutritionally essential element Se is also chemopreventive against prostate, lung, and several other leading human cancers when administered at supranutritional levels. The complex biochemical mechanism(s) underlying the anticancer action of Se compounds are not understood but they depend on Se metabolism in conjunction with multiple steps of redox regulation and antioxidation. Previously impractical, such complexity can now be explored by combining the power of new molecular profiling tools. With metabolomics-edited transcriptomic analysis (META) to guide targeted proteomics, we have recently discovered key changes in metabolic and regulatory pathways in Se-exposed lung cancer cells that control cell growth and migration. These preliminary results led to our current hypothesis: (a) the primary site(s) of Se action involve covalent modification(s) of key redox-sensitive proteins including thioredoxin reductase (TrxR) and NF:B; (b) their resultant dysfunctions lead to cell death and anti-metastasis. Here, we propose to expand the approach to human Small Cell Lung Cancer cells with different metastatic potential for in vivo validation in a RAG1 null mice model. Our specific aims are: Aim 1: To define and correlate the biochemical pathway profiles with phenotypic changes of selected human lung cancer cell lines in response to treatments of different Se forms. The metabolomics data will be used to discern metabolic pathways related to growth, apoptosis, and metastatic potential (motility, chemotaxis, and adhesion); Aim 2: To acquire global and focused gene expression profiles of the treated cells for correlation to the metabolic profiles obtained from Aim 1. Using META, gene expression profiles will be prioritized based on actual metabolic changes from Aim 1 to reveal Se action on regulatory pathways and key target proteins; Aim 3: To verify key working hypotheses in cell systems using a combination of immunochemical and proteomics analyses. [Potential key protein targets, TrxR, NF:B, and IKK2] will be verified by relating their function to the modification state; Aim 4: To validate in vivo Se action on lung cancer cell metastasis in a RAG null mouse model. Emphasis will be on metastasis involving the chemokine SDF-1 and its receptor CXCR4, which is regulated by the NF:B-TrxR pathway. Altered metastasis and molecular signature of target mice tissues and blood in response to Se treatments will be related to the cell-based molecular signatures from Aims 1-3 for in vivo validation and for connection to ongoing human patient studies. This work is expected to accelerate the development of mechanistic biomarkers for lung cancer chemoprevention, tumor diagnostics, and anticancer efficacy. PUBLIC HEALTH RELEVANCE The nutritionally essential element Selenium (Se) has been shown to have anti-cancer properties against prostate, lung and other cancers at supranutritional levels. The exact nature of this activity is presently unknown, but is related to the metabolism of selenium and how it reduces the ability of cancer cells to survive oxidative damages generated by their overactive metabolism. Here we propose to use state-of-the-science "metabolomic" plus other "'omics" tools to determine the biochemical basis of Se action in lung cancers using cell cultures and mouse models. This work is expected to accelerate the development of more sensitive diagnostics for lung cancer chemoprevention, tumor detection, and anticancer treatment.