Roles of Claudin-7 in Lung Cancer

Claudin-7 在肺癌中的作用

• 批准号: 7511411
• 负责人: YAN-HUA CHEN
• 金额: $ 7.15万
• 依托单位: EAST CAROLINA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-08 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7511411
• 关键词: 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanone; Accounting; Address; Adherens Junction; Adhesions; Alveolar; Apoptosis; Biological Models; Butanones; C57BL/6 Mouse; Cancer Cell Growth; Cancer Etiology; Cancer cell line; Carcinogens; Cell Adhesion; Cell Cycle; Cells; Cessation of life; Cultured Cells; Data; Development; Diagnosis; Disease; Dissociation; E-Cadherin; Early Diagnosis; Ectopic Expression; Engineering; Environmental Carcinogens; Environmental Risk Factor; Epithelial; Epithelial Cells; Epithelium; Exposure to; Flow Cytometry; Focal Adhesions; Foundations; Future; Gene Targeting; Genes; Genetic; Genetically Engineered Mouse; Growth; Human; Image; In Situ Nick-End Labeling; Incidence; Integrins; Intercellular Junctions; Investigation; Knock-out; Laboratories; Laboratory Study; Lasers; Lewis Lung Carcinoma; Light; Lung; Lung Neoplasms; Lung diseases; Malignant Neoplasms; Malignant neoplasm of lung; Matrigel Invasion Assay; Methods; Modeling; Molecular; Mouse Strains; Mus; Neoplasm Metastasis; Play; Prevention; Probability; Property; Protein Overexpression; Proteins; Public Health; Research; Role; Survival Rate; Tight Junctions; Transfection; Tumor Suppressor Proteins; United States National Institutes of Health; Weaning; cancer cell; carcinogenesis; catenin p120ctn protein; cell growth; chemical carcinogen; environmental chemical; host neoplasm interaction; in vivo; light microscopy; lung Carcinoma; lung carcinogenesis; matrigel; mouse model; occludin; research study; tumor; tumor progression; tumorigenesis; uncontrolled cell growth

DESCRIPTION (provided by applicant): Lung cancer is a major lung disease and accounts for more than one-fourth of all cancer deaths. Therefore, research into causes of the disease, identification of genetic and environmental risk factors, and discovery of better diagnosis and treatment strategies are urgently needed. One strategy to combat lung cancer is to identify genes that normally suppress tumor development. We have developed the first genetically engineered mouse model in which claudin-7 gene is deleted. Knockout of claudin-7 using gene targeting approach resulted in hyperproliferation of lung epithelial cells. Heterozygous claudin-7 mice showed an increased incidence of developing spontaneous lung tumors. Importantly, claudin-7 expression is either disrupted or downregulated at the cell-cell junction in lung cancer cells, and the overexpression of claudin-7 reduced human lung cancer cell growth in culture. These studies prompted the hypothesis that claudin-7 plays important roles in lung cancer progression as a tumor suppressor. To investigate how claudin-7 suppresses cancer growth in cell culture as well as in mouse models in vivo, this project will address two specific aims. Specific Aim 1: To investigate the roles of claudin-7 in lung cancer cell growth and survival in culture. We will use flow cytometry, TUNEL imaging, Matrigel invasion assay and cell- cell dissociation methods to determine if the properties of cell cycle, apoptosis, as well as cell adhesion and invasion, are altered when claudin-7 is stably expressed in a claudin-7-deficient human lung cancer cell line NCI-H1299. These experiments will determine how claudin-7 reduces lung cancer cell growth. Specific Aim 2: To investigate environmental carcinogens on the growth of lung carcinoma in vivo and on tumor-host interactions in Cln7 mice. We will investigate if environmental carcinogens, such as 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), can induce a greater tumor incidence in Cln7 mice compared to Cln7 mice. We will also investigate whether reduced claudin-7 expression results in altered host cell-cell junction and adhesion, allowing inoculated Lewis lung carcinoma LLC1 cells to interact with the pulmonary microenvironment more favorably and metastasize more easily. This project will allow us to collect preliminary data to determine whether Cln7 mouse strain is a viable model system for studies of claudin-7 function in lung carcinogenesis. These studies will also lay the foundation for a future NIH RO1 project to investigate the molecular mechanisms of how claudin-7 functions as a tumor suppressor. PUBLIC HEALTH RELEVANCE: One strategy to combat lung cancer is to identify genes that normally suppress tumor development. Claudin-7 is important in limiting lung epithelia from uncontrolled cell growth, as revealed by our genetically engineered claudin- 7 knockout mouse model. It is now important to investigate whether mice deficient in claudin-7 are more susceptible for lung cancer formation when exposed to environmental carcinogens and how claudin-7 suppresses cancer growth.

描述（由申请人提供）：肺癌是一种主要的肺部疾病，占所有癌症死亡人数的四分之一以上。因此，迫切需要研究疾病的原因，识别遗传和环境风险因素，并发现更好的诊断和治疗策略。对抗肺癌的一种策略是识别通常抑制肿瘤发展的基因。我们建立了第一个claudin-7基因缺失的基因工程小鼠模型。采用基因打靶方法敲除claudin-7导致肺上皮细胞过度增殖。杂合claudin-7小鼠显示自发性肺肿瘤发生率增加。重要的是，肺癌细胞中细胞与细胞连接处的密蛋白-7表达被破坏或下调，并且密蛋白-7的过表达减少了培养物中人肺癌细胞的生长。这些研究提示了claudin-7作为肿瘤抑制因子在肺癌进展中发挥重要作用的假设。为了研究claudin-7如何抑制细胞培养和小鼠体内模型中的癌症生长，该项目将解决两个具体目标。具体目的1：研究claudin-7在培养的肺癌细胞生长和存活中的作用。我们将使用流式细胞术、TUNEL成像、Matrigel侵袭测定和细胞-细胞解离方法来确定当紧密连接蛋白-7在紧密连接蛋白-7缺陷的人肺癌细胞系NCI-H1299中稳定表达时，细胞周期、凋亡以及细胞粘附和侵袭的性质是否改变。这些实验将确定claudin-7如何减少肺癌细胞的生长。具体目标2：研究环境致癌物对体内肺癌生长和Cln 7小鼠肿瘤-宿主相互作用的影响。我们将研究环境致癌物，如4-（甲基亚硝胺）-1-（3-吡啶基）-1-丁酮（NNK），是否可以诱导Cln 7小鼠相比，Cln 7小鼠更大的肿瘤发病率。我们还将研究减少的claudin-7表达是否会导致宿主细胞-细胞连接和粘附的改变，从而使接种的刘易斯肺癌LLC 1细胞更有利地与肺微环境相互作用并更容易转移。该项目将使我们能够收集初步数据，以确定Cln 7小鼠品系是否是一个可行的模型系统，用于研究claudin-7在肺癌发生中的功能。这些研究也将为未来的NIH RO 1项目奠定基础，该项目旨在研究claudin-7作为肿瘤抑制因子的分子机制。公共卫生相关性：对抗肺癌的一种策略是识别通常抑制肿瘤发展的基因。Claudin-7在限制肺上皮细胞不受控制的细胞生长中是重要的，如我们的基因工程claudin- 7敲除小鼠模型所揭示的。现在重要的是研究缺乏claudin-7的小鼠在暴露于环境致癌物时是否更容易形成肺癌，以及claudin-7如何抑制癌症生长。