Retrotransposition in Health and Disease

健康与疾病中的逆转录转座

• 批准号: 9105045
• 负责人: HAIG H. KAZAZIAN
• 金额: $ 53.25万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9105045
• 关键词: Adult; Affect; Alternative Splicing; Barrett Esophagus; Biological Assay; Biological Markers; Blood; Brain; Cancer Etiology; Cancer cell line; Carcinoma; Cell Culture Techniques; Cell Line; Cells; Code; Colon Adenocarcinoma; Colorectal; DNA; Data; Development; Disease; Epithelial; Event; Exons; Fostering; Frequencies; Gene Expression; Genes; Genetic Recombination; Genomics; Germ Lines; Health; Histocompatibility Testing; Human; Human Genome; Indium; Insertion Mutation; Lesion; Malignant Neoplasms; Malignant neoplasm of esophagus; Malignant neoplasm of gastrointestinal tract; Metaplasia; Mind; Mus; Neoplasm Metastasis; Nested PCR; Normal Cell; Normal tissue morphology; Organ; Pancreas; Paste substance; Patients; Phenotype; Play; Point Mutation; Polyadenylation; Polyps; Premalignant; Primary Neoplasm; Process; RNA Folding; Reporting; Retrotransposition; Retrotransposon; Risk; Role; Serum; Signal Transduction; Site; Solid Neoplasm; Somatic Cell; Techniques; Testing; Time; Tissues; carcinogenesis; neoplastic cell; neural precursor cell; novel; outcome forecast; premature; promoter; public health relevance; single cell sequencing; transposon/insertion element; tumor; tumor DNA; tumor progression; tumor xenograft; tumorigenesis

 DESCRIPTION (provided by applicant) Although we used to believe that all retrotransposition occurred in the germ line in humans, over the past 10 years it has become clear that somatic retrotransposition, especially of LINE1s (L1s), is prominent, at least in the brain and in epithelial cancers. A number of groups have shown retrotransposition in neural precursor cells and the adult brain. Likewise, a number of groups including our own have shown significant retrotransposition in gastrointestinal cancers. A key finding of our studies is that most L1 insertions in GI cancers occur very early in cancer development. Indeed, some of the insertions are found in low concentration (detected only by nested PCR) in normal cells, but they become essentially clonal in the cancer (detected by conventional PCR). ln this application, we strive to answer two big questions in the field. First, does significant retrotransposition occur in adult somatic tissues outside of the brain and, if so, at what frequency? In this aim we will study L1 insertions in single normal cells near the tumors to find what fraction of the insertions in the tumor are already present in normal cells. We will determine if retrotransposition rate is greater in normal cells or in tumor cells. We will also stuy the frequency of insertions in single normal cells not associated with cancer and from various organs to determine if some tissue types have a greater propensity for retrotransposition than others. The second big question is: Does L1 somatic retrotransposition have any significant role in the etiology of cancer? We need to determine whether we can alter the cellular phenotype towards normal by deletion of somatic L1 insertions found in cancer-related genes in cancer-derived cell lines.

 描述（由申请人提供） 尽管我们过去认为所有的逆转录转座都发生在人类的生殖细胞系中，但在过去的10年里，体细胞逆转录转座，特别是LINE1s（L1s）的逆转录转座，至少在大脑和上皮癌中是突出的。许多研究小组已经证明了神经前体细胞和成人大脑中的逆转录转座。同样，包括我们自己的研究小组在内的许多研究小组在胃肠道癌症中也显示了显著的逆转录转座。我们研究的一个关键发现是，大多数胃肠道癌症中的L1插入发生在癌症发展的早期。事实上，在正常细胞中发现一些低浓度的插入（仅通过巢式PCR检测），但它们在癌症中基本上成为克隆（通过常规PCR检测）。在这个应用程序中，我们努力回答这个领域的两个大问题。首先，在大脑外的成人躯体组织中是否发生了显著的逆转录转座，如果是， 什么频率？为此，我们将研究肿瘤附近单个正常细胞中的L1插入，以发现肿瘤中的插入部分已经存在于正常细胞中。我们将确定逆转录转座率在正常细胞或肿瘤细胞中是否更高。我们还将研究与癌症无关的单个正常细胞和各种器官中插入的频率，以确定某些组织类型是否比其他组织类型具有更大的逆转录转座倾向。第二个大问题是：L1体细胞反转录转位在癌症的病因学中是否有任何重要作用？我们需要确定我们是否可以通过删除癌源细胞系中癌症相关基因中的体细胞L1插入来改变细胞表型。