Dissecting the role of TCF7L1 in colorectal cancer

剖析 TCF7L1 在结直肠癌中的作用

• 批准号: 10040673
• 负责人: Gregory S. Yochum
• 金额: $ 15.83万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-10 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10040673
• 关键词: Accounting; Address; Anchorage-Independent Growth; Binding; Binding Sites; Biological Assay; Cancer Cell Growth; Cancer Etiology; Cell Cycle; Cell Cycle Progression; Cell Nucleus; Cell Proliferation; Cells; Cessation of life; ChIP-seq; Chromatin; Clinic; Clinical Management; Colorectal Cancer; Colorectal Neoplasms; Complementary DNA; Complex; Consensus; DNA; DNA Binding; DNA Binding Domain; Data; Development; Disease; Elements; Enhancers; Family; Family member; Future; Gene Expression; Genes; Genetic Enhancer Element; Genetic Transcription; Genomic approach; Growth; Health; Human; In Vitro; Individual; Knowledge; Lead; Lesion; Literature; Microarray Analysis; Mitotic Cell Cycle; Modeling; Molecular; Mucous Membrane; Mutation; Nuclear; Oncogenes; Oncogenic; Operative Surgical Procedures; Pathologic; Pathway interactions; Patients; Point Mutation; Prevalence; Publishing; Recurrent disease; Regulation; Regulator Genes; Regulatory Element; Reporting; Research; Residual Tumors; Role; Signal Pathway; Signal Transduction; Surveys; System; TCF Transcription Factor; TCF7L2 gene; Therapeutic; Therapeutic Intervention; Tissues; Transcript; Transcription Coactivator; Transcription Repressor; Tumorigenicity; United States; WNT Signaling Pathway; Work; advanced disease; beta catenin; c-myc Genes; cancer cell; carcinogenesis; cell growth; cellular transduction; chemotherapy; colon cancer cell line; colon cancer patients; colon carcinogenesis; design; differential expression; effective therapy; functional genomics; genetic signature; genome-wide; in vivo; inhibitor/antagonist; knock-down; member; mortality; mutant; novel; programs; recruit; small hairpin RNA; targeted treatment; transcription factor; transcriptome; transcriptome sequencing; treatment strategy; tumor; tumorigenesis; vector

PROJECT SUMMARY Deregulated Wnt/β-catenin signaling is a common feature of colorectal cancer (CRC), but how this pathway corrupts target gene expression is not fully understood. The T-cell factor/Lymphoid enhancer factor (TCF/Lef; hereafter TCF) transcription factors bind Wnt-responsive DNA elements (WREs) to control Wnt/β-catenin target gene expression. Of the four TCF family members (TCF7, LEF1, TCF7L1, and TCF7L2) very little is known about TCF7L1 in CRC and the set of target genes it directly regulates. By using shRNAs to deplete TCF7L1 in established human CRC lines, we found that it promotes cell growth. Although microarray analysis of transcripts differentially expressed in TCF7L1 knockdown cells versus controls uncovered hundreds of genes, surprisingly, we failed to identify a Wnt target gene signature among this list. Moreover, published ChIP-Seq data indicates that a substantial fraction of TCF-bound DNA elements lack consensus TCF binding motifs. These findings suggest that TCF7L1 may primarily function outside the canonical Wnt signaling pathway to promote oncogenesis. Additional work is needed to identify the constellation of direct target genes that TCF7L1 regulates and whether its DNA-binding function is required to promote CRC growth. In Aim 1, we will identify the TCF7L1-transcriptome by conducting unbiased and genome-wide functional genomics approaches in control and TCF7L1-depleted CRC cells. In TCF7L1-depleted lines, we will introduce wild-type and DNA-binding deficient TCF7L1 cDNAs to classify targets whose expression is regulated independently of direct TCF7L1 binding to DNA. In Aim 2, we will determine whether the DNA-binding capacity of TCF7L1 is required for CRC cell proliferation, progression through the cell cycle, growth in an anchorage-independent manner, and tumorigenesis in vivo. We will also assess whether non-canonical targets are differentially expressed in primary human colonic tissues and tumors. The vast majority of existing therapeutics designed to target the Wnt pathway have focused on nuclear TCF/β-catenin complexes as the key regulator of the CRC transcriptome. Our findings will establish TCF7L1 as a critical regulator of genes outside the canonical Wnt/β- catenin pathway and will open a whole new field of research to exploit those targets for therapeutic intervention.

项目摘要 Wnt/β-catenin信号通路失调是结直肠癌（CRC）的常见特征，但该通路如何 破坏靶基因表达的机制还不完全清楚。T细胞因子/类磷脂增强因子（TCF/Lef; 此后称为TCF）转录因子结合Wnt响应性DNA元件（WRE）以控制Wnt/β-连环蛋白 靶基因表达。在四个TCF家族成员（TCF 7、LEF 1、TCF 7 L1和TCF 7 L2）中， 关于CRC中的TCF 7 L1及其直接调节的靶基因集的已知信息。通过使用shRNA来消除 TCF 7 L1在建立的人CRC细胞系中，我们发现它促进细胞生长。虽然微阵列分析 在TCF 7 L1敲除细胞与对照细胞中差异表达的转录本中， 然而，令人惊讶的是，我们未能在该列表中鉴定出Wnt靶基因签名。此外，出版 ChIP-Seq数据表明，相当一部分TCF结合的DNA元件缺乏共有TCF结合 图案这些发现表明，TCF 7 L1可能主要在经典Wnt信号传导之外发挥作用。 促进肿瘤发生的途径。需要进一步的工作来确定直接靶基因的星座 TCF 7 L1的调节以及其DNA结合功能是否是促进CRC生长所必需的。目标1： 将通过进行无偏倚和全基因组功能基因组学来鉴定TCF 7 L1转录组 在对照和TCF 7 L1耗尽的CRC细胞中的方法。在TCF 7 L1缺失的品系中，我们将引入野生型 和DNA结合缺陷型TCF 7 L1 cDNA来分类其表达独立于 直接与DNA结合的TCF 7 L1。在目标2中，我们将确定TCF 7 L1的DNA结合能力是否是 所需的CRC细胞增殖，通过细胞周期的进展，生长在一个锚定的独立 方式，和体内肿瘤发生。我们还将评估非典型靶点是否与 在原代人结肠组织和肿瘤中表达。绝大多数现有的治疗方法， 针对Wnt通路的研究集中在细胞核TCF/β-连环蛋白复合物上，作为CRC的关键调节因子 转录组我们的研究结果将确立TCF 7 L1作为经典Wnt/β-SMA基因以外的基因的关键调节因子。 连环蛋白通路，并将开辟一个全新的研究领域，利用这些目标的治疗 干预

项目成果

TCF7L1 Regulates LGR5 Expression in Colorectal Cancer Cells.

• DOI: 10.3390/genes14020481
• 发表时间: 2023-02-14
• 期刊: GENES
• 影响因子: 3.5
• 作者: King, Carli M.;Marx, Olivia M.;Ding, Wei;Koltun, Walter A.;Yochum, Gregory S.
• 通讯作者: Yochum, Gregory S.