用于高通量药物筛选的斑马鱼c-myb过表达白血病模型的建立

Drug screening based on the zebrafish animal model has become a core technology to discover new drugs. c-Myb as an important transcription factor is involved in hematopoietic development and differentiation process, and its expression defects can directly lead to human myeloid or lymphoid leukemia. However, none ideal zebrafish model was provided to have a deep insight of leukemia caused by c-myb. We've got a c-myb over expression transgenic zebrafish, phenotypic preliminary analysis found that: ① The c-myb over expression fish had abnormal myeloid progenitor cell differentiation and granulocyte hyperplasia in the early stage; ② Lymphocytes defect in the early stage and late recovery; ③ The percentage of granulocyte in the kidney marrow is significant higher in the c-myb over expression transgenic zebrafish than in wild-types. ④ Part of 1.5 year old c-myb over expression zebrafish show a lymphocytic infiltrates phenotype. We assume that c-myb overexpression zebrafish is likely to be a chronic neutrophilic leukemia/atypical chronic myeloid leukemia (CNL/ACML) animal model, and some of them can progress to acute myeloid leukemia (AML) or acute lymphoid leukemia (ALL). But how similarity between c-myb transgenic zebrafish model and human disease, what are the key factors in the progress of CNL/ACML upgrade to AML or ALL still need to be solved. In this proposed research, we aim (1) to identify phenotype of the c-myb over expression fish; (2) to establish an ideal zebrafish leukemia model and investigate its pathogenesis, typology, clinic data comparison; and (3) to verify the model using some known clinic drugs. These studies will further deepen our mechanistic understanding of myeloid lineage development in general and the CNL/ACML animal models will provide new molecular markers for early diagnosis, prognosis, treatment effect evaluation and new strategies for drug discovery and therapeutic treatments.

基于斑马鱼疾病模型的药物筛选已经成为新药发现的核心技术。c-myb作为重要的转录因子参与造血发育和分化过程，其过表达缺陷会导致人髓系或淋系白血病。但目前还缺少c-myb白血病动物模型。 我们获得一个c-myb过表达转基因斑马鱼，发现具有以下表型：①早期髓系祖细胞分化异常，粒细胞明显增生；②早期淋系缺陷，晚期恢复；③成鱼肾脏血中粒系增多。④1.5年龄斑马鱼中部分出现淋巴细胞全身浸润。总体表型类似人慢性中性粒细胞白血病/非典型慢性髓系白血病（CNL/ACML），其中部分可进展为急性髓系白血病（AML）或急性淋系白血病（ALL）。我们假设该c-myb转基因斑马鱼是一种特殊类型的白血病模型，但其与人CNL/ACML的相似性、进展为AML或ALL的关键因素及动物模型建立等科学问题仍需解决。 本项目拟进行：①表型鉴定；②白血病模型的建立及其发病机制、分型和临床比对；③已知药物对斑马鱼模型的药理学验证。

完成了c-MYB异常激活白血病斑马鱼模型研究。c-MYB作为调节造血细胞增殖及分化的重要转录因子，其活性的失调往往伴随着各种各样的造血紊乱以及血液病，然而由于缺少c-MYB相关动物模型，其致病机理仍尚不清楚。研究者发现在c-myb-gfp转基因斑马鱼中，从胚胎期到成鱼期均表现出异常粒细胞增多，类似人类骨髓增生异常综合症(MDS)。进一步研究发现，c-myb异常激活的斑马鱼成鱼会进展为类急性髓系白血病(AML)或者类急性淋巴细胞白血病(ALL),而这种髓系或淋系恶性肿瘤很很可能是由c-myb异常激活引起的， c-myb异常激活会导致细胞周期相关基因调节紊乱以及造血前体细胞的增殖增多。利用c-myb的靶向药物夫拉平度可以缓解c-myb异常激活的幼鱼以及成鱼类MDS表型。基于以上发现，研究者建立了一个研究c-Myb相关白血病生成的细胞及分子机制的斑马鱼模型，通过该模型可以进行抗白血病相关药物的评估及筛选。论文链接：http://www.nature.com/leu/journal/vaop/naam/abs/leu2016170a.html.[Leukemia，doi:10.1038/leu.2016.170]