Wnt Signaling in Colon Cancer

结肠癌中的 Wnt 信号转导

基本信息

批准号：
8448303
负责人：
Marian L Waterman
金额：
$ 26.93万
依托单位：
UNIVERSITY OF CALIFORNIA-IRVINE
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-04-01 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8448303
关键词：
Affect Binding Binding Sites Biochemical Biological Biological Assay Cell Culture Techniques Cell Cycle Progression Cell Nucleus Cell Proliferation Cell membrane Cells ChIP-seq Colon Colon Carcinoma Colorectal Cancer Complex Consensus Sequence DNA Binding DNA Binding Domain DNA Sequence Data Databases Dominant-Negative Mutation Elements Epithelial Epithelium Equilibrium Family Family member Funding Gene Chips Gene Expression Regulation Gene Mutation Gene Targeting Genes Genetic Genome Goals Human In Vitro Intestines Lead Left Length Ligands Link Machine Learning Malignant Neoplasms Mammalian Cell Mediating Microarray Analysis Modeling Mutation Normal Cell Nuclear Nuclear Export Pathway interactions Pattern Phenotype Protein Binding Protein Isoforms Proteins RNA Splicing Recruitment Activity Response Elements Signal Transduction Site Specificity System TCF Transcription Factor TCF7L2 gene Testing Therapeutic Intervention Tissues autocrine cancer cell cancer genome carcinogenesis cell type colon cancer cell line colon carcinogenesis expectation extracellular genome-wide human disease matrigel member paracrine promoter public health relevance receptor research study tool transcription factor tumor initiation tumor progression

项目摘要

DESCRIPTION (provided by applicant): Wnt signaling is one of the most common pathways linked to carcinogenesis in the intestine. The transcription factors that mediate Wnt signals are members of the Lymphoid Enhancer Factor/T Cell Factor (LEF/TCF) family. This four-member family is complex in that there are full-length activating forms, truncated dominant negative forms, and alternatively spliced isoforms that modify Wnt target gene recognition. TCF-1 and TCF-4 are the two family members expressed in the epithelial crypt compartment of the intestine. Normally, TCF-1 is expressed as a dominant negative isoform and it counteracts the action of TCF-4 which is expressed as a Wnt-mediating, active isoform. This pattern changes in cancer because TCF-1 expression switches to a full-length, Wnt mediating form. We have discovered a second DNA binding domain in TCF-1 and TCF-4 isoforms called the C-clamp. We have shown that the C-clamp is important for regulating cell proliferation of colon cancer cells. We have also identified Wnts that trigger TCF-1 export in colon cancer cells. Export of TCF-1 leaves the C-clamp form of TCF-4 in the nucleus to mediate aberrant Wnt signaling. Three aims are proposed for this project. First, the extracellular Wnts and intracellular components that direct TCF-1 nuclear export will be defined (Aim1). Second, the biological impact of export will be defined in colon cancer cells and colon cancer initiating 3D cultures (Aim2). Third, the DNA binding specificities and target gene selection of C-clamp forms of TCF-1 and TCF-4 will be defined through genome-wide binding assays (ChIP-Seq), high-throughput protein binding microarrays, and in vitro biochemical analysis (Aim3). The overall goal is to define the mechanisms behind changes in TCF expression in colon carcinogenesis, and to define how extracellular Wnts and DNA binding specificities of TCFs influence aberrant signaling in colon cancer cells with stabilized ?-catenin.

描述（由申请人提供）：Wnt信号传导是与肠中癌变有关的最常见途径之一。介导Wnt信号的转录因子是淋巴增强因子/T细胞因子（LEF/TCF）家族的成员。这个四成员的家族很复杂，因为存在全长激活形式，截断的主要负面形式以及修改Wnt靶基因识别的剪接的同工型。 TCF-1和TCF-4是在肠上皮地上隐窝中表达的两个家庭成员。通常，TCF-1表示为主要的负同工型，它抵消了TCF-4的作用，TCF-4的作用表示为一种导致WNT的活性同工型。由于TCF-1表达转换为全长的Wnt介导形式，因此这种模式在癌症中发生了变化。我们在TCF-1和TCF-4的同工型中发现了第二个DNA结合结构域，称为C板夹。我们已经表明，C钳对于调节结肠癌细胞的细胞增殖很重要。我们还确定了触发结肠癌细胞中TCF-1出口的WNT。 TCF-1的导出使核中TCF-4的C板板形式介导异常的Wnt信号传导。该项目提出了三个目标。首先，将定义直接TCF-1核输出的细胞外WNT和细胞内组件（AIM1）。其次，出口的生物学影响将在结肠癌细胞和结肠癌引发3D培养物中定义（AIM2）。第三，将通过全基因组结合测定法（chip-seq），高通量蛋白结合微阵列和体外生物化学分析来定义DNA结合特异性和TCF-1和TCF-4的C-clamp形式的靶基因选择（AIM3）。总体目标是定义结肠癌中TCF表达的变化背后的机制，并定义TCF的细胞外Wnts和DNA结合特异性如何影响稳定的结肠癌细胞中异常信号传导？