Development of a fish model for dyskeratosis congenita and cancer research

描述(申请人提供)：端粒酶在细胞永生中起关键作用，在大多数肿瘤细胞以及干细胞和生殖细胞系中都有表达。一些端粒酶基因的突变，如端粒酶逆转录酶(TERT)，已被认为与人类疾病有关，如先天性角化不良(DKC)和再生障碍性贫血(AA)，这些疾病有骨髓衰竭的症状。端粒酶缺乏的生物学后果大多是用培养的人类细胞或小鼠作为动物模型来研究的。硬骨鱼，如斑马鱼和青花鱼，在过去的几十年里已经成为强大的遗传模型系统。它们体积小，每代后代数量多，是生物医学研究的有吸引力的脊椎动物模型。我们已经成功地培育出了一种突变的青冈鱼，它在青冈鱼的TERT基因中含有无义突变TERTK195X。这是有史以来第一个端粒酶缺陷的FISH模型。这一计划的总体目标是开发和使用青竹FISH模型来研究端粒和端粒酶，以及它们在DKC和肿瘤发生中的作用。该项目的第一个具体目标将集中在TERTK195X突变青竹鱼的端粒长度、表型和生殖细胞缺陷的特征上。第二个具体目标将集中在端粒酶缺陷和端粒功能障碍在造血和肿瘤发生中的作用。公共卫生相关性：端粒酶是细胞永生的关键酶，在癌症、衰老和几种人类疾病中发挥关键作用，包括先天性角化不良、再生障碍性贫血和特发性肺纤维化。通过产生一种缺乏端粒酶的突变FISH，我们将开发一个强大的FISH模型系统，用于研究端粒酶和端粒在细胞中的生物学作用，并寻找治疗癌症和端粒酶功能障碍疾病的潜在方法。

DESCRIPTION (provided by applicant): Telomerase plays a crucial role in cellular immortality and is expressed in most tumor cells as well as stem cells and germ lines. Mutations in several telomerase genes, e.g. telomerase reverse transcriptase (TERT), have been genetically linked to human diseases such as dyskeratosis congenita (DKC) and aplastic anemia (AA) that have symptoms of bone marrow failure. The biological consequences of telomerase deficiency have been studied mostly using cultured human cells or mice as an animal model. Teleost fish, such as zebrafish and medaka fish, have emerged as powerful genetic model systems in the past few decades. They are attractive vertebrate models for biomedical research because of their small size and large numbers of progeny per generation. We have successfully generated a mutant medaka fish that contains a nonsense mutation TERTK195X in the medaka TERT gene. This is the first telomerase-deficient fish model ever created. The overall goal of this proposed program is to develop and use the medaka fish model for the study of telomeres and telomerase, and their role in DKC and tumorigenesis. The first specific aim of this project will focus on characterization of telomere length phenotype and germ cell defect of the TERTK195X mutant medaka fish. The second specific aim will focus on the role of telomerase deficiency and telomere dysfunction in hematopoiesis and tumorigenesis. PUBLIC HEALTH RELEVANCE: Telomerase is an enzyme crucial for cellular immortality and play critical roles in cancer, aging and several human diseases including dyskeratosis congenita, aplastic anemia and idiopathic pulmonary fibrosis. By generating a mutant fish that lacks telomerase enzyme, we will develop a powerful fish model system for studying the biological roles of telomerase and telomeres in cells, and finding potential cures for cancer and telomerase-dysfunction diseases.