The pH-dependent adaptive advantage for recurrent histidine mutations in cancer

癌症中复发性组氨酸突变的 pH 依赖性适应性优势

基本信息

批准号：
8892120
负责人：
Katharine Alice White
金额：
$ 5.42万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-08-01 至 2016-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8892120
关键词：
Acute Myelocytic Leukemia Acute T Cell Leukemia Affinity Amino Acids Apoptosis Appearance Arginine Binding Biochemical Bioinformatics Cataloging Catalogs Cell Proliferation Cell physiology Cells Clonal Expansion Codon Nucleotides Complex DNA Modification Methylases Databases Dependence Development Dimerization Disease Drug resistance Epidermal Growth Factor Receptor FBXW7 gene Frequencies Genetic Health Histidine Homodimerization Human Hydrogen Bonding Investigation Laboratories Link Malignant - descriptor Malignant Neoplasms Malignant neoplasm of lung Mesothelioma Metabolism Molecular Conformation Mutation Normal Cell Oncogenic Outcome Outcome Study Pathway interactions Phosphotransferases Process Proteins Recurrence Regulatory Pathway Relative (related person)Serine Site Somatic Mutation Source Survival Rate Testing Threonine Tissues Tumor Suppressor Proteins Tyrosine Ubiquitination Work cancer cell design enzyme activity extracellular fitness improved in vitro Assay insight molecular dynamics mutant novel therapeutic intervention pH gradient pressure programs sensor success therapeutic target trait tumor progression ubiquitin ligase

项目摘要

DESCRIPTION (provided by applicant): Dysregulated pH is a hallmark of nearly all cancers regardless of tissue origin or genetic background. In normal cells, extracellular pH (pHe) is higher than intracellular pH (pHi) but in cancer cells this pH gradient is reversed. While the constitutive increase in pHi is small, it produces substantial changes in cell function. For example, the the increased pHi of cancer cells promotes cell proliferation and invasion while inhibiting apoptosis and altering cell metabolism. Here, we propose to investigate somatic mutations in cancer that may be conferring an increased fitness for the dysregulated pH of cancer. While somatic mutations in cancer are random, the increased pHi of cancers could provide a selective pressure for mutations that confer an adaptive advantage. Our hypothesis is that this selective pressure causes the conservation of histidine mutations in cancer that confer a gain in pH sensitivity. To investigate this hypothesis, in Aim 1 we will determine whether commonly occurring Arg>His mutations in candidate proteins confer a gain in pH-dependent function and what the mechanism of pH sensing might be. For each candidate we will test predictions that mutant but not wild- type proteins have pH-dependent functions by using biochemical assays in vitro and in cells. We also will test mechanisms of pH sensing of mutants by using molecular dynamics simulations and computational pKa predictions. In Aim 2 we will use database analyses to identify additional candidates with recurring histidine mutations, determine their frequency relative to codon bias frequency, and generate interaction networks to predict how these mutations might be conferring a functional adaptive advantage to cancer cells. These objectives will be achieved by using a database of amino acid mutations generated for the sponsor's laboratory from the Catalogue Of Somatic Mutations In Cancer (COSMIC) and established bioinformatics programs. To our knowledge this is the first examination of the adaptive retention and pH-dependent function of somatic mutations involving histidines in cancer. Our findings will generate new insights into how somatic mutations might be linked to the dysregulated pH in cancer. The results of this work might also reveal broad design principles of pH sensors that could inform the development of cancer therapeutics targeting pH-dependent pathways, regulatory mechanisms, or driver mutations.

描述（由申请人提供）：不管组织起源或遗传背景如何，失调的pH值是几乎所有癌症的标志。在正常细胞中，细胞外pH（PHE）高于细胞内pH（PHI），但在癌细胞中，这种pH梯度反转。虽然PHI的本构增加很小，但它会在细胞功能上产生实质性变化。例如，癌细胞的PHI增加促进了细胞的增殖和浸润，同时抑制细胞凋亡和改变细胞代谢。在这里，我们建议研究癌症中的体细胞突变，以提高癌症失调的适应性。虽然癌症中的体细胞突变是随机的，但癌症的PHI增加可能为赋予适应性优势的突变提供选择性压力。我们的假设是，这种选择性压力会导致癌症中组氨酸突变的保存，从而赋予pH敏感性增长。为了研究这一假设，在目标1中，我们将确定通常发生的arg>他在候选蛋白中的突变是否赋予pH依赖性功能的增益以及pH传感的机理可能是什么。对于每个候选者，我们将通过在体外和细胞中使用生化分析来测试突变体而不是野生型蛋白具有pH依赖性功能的预测。我们还将通过使用分子动力学模拟和计算PKA预测来测试突变体pH传感的机制。在AIM 2中，我们将使用数据库分析来鉴定具有复发组氨酸突变的其他候选者，确定其相对于密码子偏置频率的频率，并生成相互作用网络以预测这些突变如何赋予对癌细胞的功能适应性优势。这些目标将通过使用癌症（宇宙）体细胞突变目录并建立的生物信息学计划的目录为赞助者实验室生成的氨基酸突变数据库实现。据我们所知，这是对涉及癌症组氨酸的体细胞突变的适应性保留和pH依赖性功能的首次检查。我们的发现将产生新的见解，即如何将体细胞突变与癌症失调的pH值联系起来。这项工作的结果还可能揭示了pH传感器的广泛设计原理，这些设计原理可以告知靶向pH依赖性途径，调节机制或驱动器突变的癌症治疗剂的发展。