Mechanisms of Serrated Colon Tumor Suppression

锯齿状结肠肿瘤抑制机制

• 批准号: 10681608
• 负责人: MICHAEL P. VERZI
• 金额: $ 39.25万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-08 至 2028-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10681608
• 关键词: ATAC-seq; Address; Adenocarcinoma; BRAF gene; Benign; Binding; Biopsy; CDX2 gene; Cell Differentiation Induction; Cell Nucleus; Cells; Chemoprevention; Chromatin; Colon; Colon Carcinoma; Colonic Neoplasms; Colorectal Cancer; Data; Differentiated Gene; EGF gene; Early Diagnosis; Environment; Epithelial Cells; Epithelium; Event; Genes; Genetic; Genetic Models; Genetic Transcription; Genome; Goals; Grant; Growth; Hour; Human; Inflammatory; Injury; Intestines; KRAS2 gene; Knowledge; MADH4 gene; MAP Kinase Gene; MAPK1 gene; MAPK3 gene; Maps; Measurement; Measures; Modeling; Molecular; Monitor; Mus; Mutate; Mutation; Natural regeneration; Nuclear; Oncogenic; Pathway interactions; Patients; Phosphorylation; Pre-Clinical Model; Predisposition; Prevention strategy; Prognosis; Proteins; Publishing; Regulator Genes; Research; Screening for cancer; Signal Transduction; Testing; Therapeutic; Tissues; Transgenic Model; Tumor Suppression; Tumor Suppressor Proteins; Work; cancer initiation; cancer subtypes; epigenomics; epithelial injury; fetal; gain of function mutation; genomic locus; in vivo; in vivo Model; injury and repair; innovation; intestinal epithelium; mouse model; mutant; new technology; permissiveness; preservation; prevent; programs; recruit; regenerative; response; restoration; stem cell differentiation; stem cell division; stem cells; therapeutic evaluation; tissue repair; tool; transcription factor; transcription factor CDX2; transcriptome; transcriptome sequencing; tumor; tumor initiation; tumorigenesis; ATAC-seq; Address; Adenocarcinoma; BRAF gene; Benign; Binding; Biopsy; CDX2 gene; Cell Differentiation Induction; Cell Nucleus; Cells; Chemoprevention; Chromatin; Colon; Colon Carcinoma; Colonic Neoplasms; Colorectal Cancer; Data; Differentiated Gene; EGF gene; Early Diagnosis; Environment; Epithelial Cells; Epithelium; Event; Genes; Genetic; Genetic Models; Genetic Transcription; Genome; Goals; Grant; Growth; Hour; Human; Inflammatory; Injury; Intestines; KRAS2 gene; Knowledge; MADH4 gene; MAP Kinase Gene; MAPK1 gene; MAPK3 gene; Maps; Measurement; Measures; Modeling; Molecular; Monitor; Mus; Mutate; Mutation; Natural regeneration; Nuclear; Oncogenic; Pathway interactions; Patients; Phosphorylation; Pre-Clinical Model; Predisposition; Prevention strategy; Prognosis; Proteins; Publishing; Regulator Genes; Research; Screening for cancer; Signal Transduction; Testing; Therapeutic; Tissues; Transgenic Model; Tumor Suppression; Tumor Suppressor Proteins; Work; cancer initiation; cancer subtypes; epigenomics; epithelial injury; fetal; gain of function mutation; genomic locus; in vivo; in vivo Model; injury and repair; innovation; intestinal epithelium; mouse model; mutant; new technology; permissiveness; preservation; prevent; programs; recruit; regenerative; response; restoration; stem cell differentiation; stem cell division; stem cells; therapeutic evaluation; tissue repair; tool; transcription factor; transcription factor CDX2; transcriptome; transcriptome sequencing; tumor; tumor initiation; tumorigenesis

A lack of knowledge about the initiating moments of tumorigenesis leaves large gaps in our ability to detect cancer early or develop prevention strategies. Our primary objective of this competitive renewal is to define, in vivo, the immediate consequences of oncogenic mutations in BRAF during Serrated colon cancer formation. We will pursue these studies in colon stem cells, the presumed cell-of-origin of colon cancer. Work from the previous grant identified new genetic modifiers of Serrated tumorigenesis. We found that oncogenic BRAFV600E mutations paradoxically cause stem cells to differentiate rather than form tumors. However, when we inactivated tumor suppressor transcription factors CDX2 or SMAD4, Serrated tumorigenesis was markedly restored. Excitingly, we found that CDX2 and SMAD4 target genes can be used to stratify human patients for their susceptibility to Serrated tumors. The logical extension of these studies is to understand the molecular mechanisms that occur in stem cells in response to BRAFV600E mutations. We will focus on the downstream transcriptional effector of BRAF, pERK, and will leverage the genetic mouse models we created to address the following Aims: Our previous work found that the transcription factor CDX2 preserves mature colon identity, with fetal- specific chromatin regions opening upon CDX2-loss. We predict that pERK takes advantage accessible chromatin upon CDX2 loss. Aim 1 will compare the activity of pERK in wild type stem cells, and BRAFV600E or CDX2-mutant stem cells. State-of-the-art –omics approaches will allow first-of-a-kind measurements of pERK on stem cell chromatin, within hours after the BRAFV600E mutation is expressed from its endogenous locus. We will measure pERK binding activity, nuclear localization, and dynamic interactions with its protein partners. Aim 2 will look at the downstream gene regulatory consequences of the BRAFV600E mutation in stem cells lacking SMAD4. We previously demonstrated that SMAD4 loss predisposes mice to Serrated tumor formation, and SMAD4 is frequently mutated in human tumors. We predict that SMAD4 works with pERK to promote differentiation and suppress stem cell renewal. Epigenomics approaches will map pERK binding to the genome, and ATAC-seq and RNA-seq will profile changes to chromatin and the transcriptome. Finally, Aim 3 will functionally test a model that the injury/repair cycle in the colon can create a susceptible environment for BRAF-pERK to drive tumorigenesis, with the prediction that an altered transcriptional network is permissive to Serrated tumor formation during the injury/repair cycle. These studies would provide important pre-clinical models to help explain and test therapeutic strategies to suppress Serrated tumor initiation in humans. These studies are innovative with cutting edge -omics applications and GEMMs and significant in exploring untested mechanisms of oncogenic pERK in stem cells. Successful completion of these studies will have us poised to test therapeutic strategies for the prevention or early detection of Serrated Colon Cancer.

缺乏关于肿瘤发生的发射时刻的知识 检测早期癌症或预防发展策略。我们这种竞争更新的主要目标是 在体内定义了锯齿状结肠癌期间BRAF的致癌突变的直接后果 形成。我们将在结肠癌的假定细胞结肠干细胞中进行这些研究。 以前的赠款的工作确定了锯齿状肿瘤发生的新遗传修饰符。我们发现 致癌性BRAFV600E突变自相矛盾地导致干细胞分化而不是形成肿瘤。 但是，当我们灭活肿瘤抑制转录因子CDX2或SMAD4时， 肿瘤发生明显恢复。令人兴奋的是，我们发现CDX2和SMAD4靶基因可以使用 分层人类患者对锯齿状肿瘤的敏感性。 这些研究的逻辑扩展是了解茎中发生的分子机制 响应BRAFV600E突变的细胞。我们将重点关注BRAF的下游转录效应子， PERK，并将利用我们创建的遗传鼠标模型来解决以下目标： 我们以前的工作发现，转录因子CDX2保持成熟的结肠身份，胎儿 - 特异性染色质区域在CDX2损伤时开放。我们预计PERK会利用优势 染色质CDX2损失。 AIM 1将比较野生型干细胞中PERK的活性，以及​​BRAFV600E或 CDX2突变的干细胞。最先进的–omics方法将允许首先测量PERK 在干细胞染色质上，在BRAFV600E突变后几个小时内从其内源基因座表达。我们 将测量PERK结合活性，核定位和与蛋白质伴侣的动态相互作用。 AIM 2将研究茎中Brafv600E突变的下游基因调节后果 缺乏SMAD4的细胞。我们先前证明SMAD4损失使小鼠倾向于锯齿状肿瘤 形成，SMAD4经常在人类肿瘤中突变。我们预测SMAD4可与Perk一起使用 促进分化并抑制干细胞更新。表观基因组学方法将映射PERK结合到 基因组和ATAC-SEQ和RNA-SEQ将介绍染色质和转录组的变化。最后，目标3 将在功能上测试一个模型，即结肠中的伤害/维修周期可以为 BRAF-PERK驱动肿瘤发生，预测转录网络的变化是允许的 损伤/修复周期中锯齿状肿瘤形成。这些研究将提供重要的临床前 有助于解释和测试治疗策略以抑制人类锯齿状肿瘤倡议的模型。 这些研究具有创新的，具有最先进的应用程序和GEMM，并且很重要 探索干细胞中致癌特权的未经测试机制。这些研究的成功完成将 让我们毒害用于预防或早期发现锯齿状结肠癌的治疗策略。