Regulators of Melanocyte and Melanoma Cell Identity

描述（由申请人提供）：黑素细胞是皮肤中产生色素的细胞，来源于多能神经嵴细胞。黑素细胞的特化需要称为小眼症相关转录因子（Mitf）的转录因子的活性。除了指导黑素细胞的形成外，Mitf的正常功能也作为谱系癌基因与黑色素瘤的异常性质相关联。这项建议旨在更好地了解如何改变黑素细胞谱系特征，并将测试的假设，不利于黑素细胞的形成和生存的机制也可能抑制黑色素瘤的形成。脊椎动物模式生物Danio rerio（斑马鱼）将用于1）鉴定抑制mitf表达从而不利于黑素细胞产生的化学物质，2）使用神经嵴转录因子的错误表达使神经嵴细胞偏离黑素细胞谱系或将定型黑素细胞重编程为不同但相关的神经嵴谱系（即神经胶质细胞/许旺细胞）。在第一种方法中，使用约2280种生物活性化合物的高通量化学遗传筛选正在完成，以确定在发育中的斑马鱼胚胎中特异性降低mitf表达的化学物质。将测定可再现地降低mitf表达的化合物对神经嵴干细胞、前体和定向后代（例如神经胶质、神经、软骨）的影响，以确定每种化合物在神经嵴发育中的何处起作用。基于mitf抑制化合物的可能作用机制，将使用斑马鱼中的标准功能获得和丧失方法来建立影响mitf表达的调节机制。在第二种方法中，通过迫使与相邻的雪旺细胞神经嵴谱系的形成相关的转录因子的表达，将改变斑马鱼中发育和定型黑素细胞的谱系身份。将在斑马鱼黑素瘤模型中测试显示在发育期间偏离黑素细胞或重编程定型黑素细胞的转录因子与所鉴定的mitf抑制化合物的组合，以测试其防止新生黑素瘤肿瘤形成和/或引起其消退的能力。 考夫曼博士是Dana Farber癌症研究所（DFCI）成人肿瘤学的临床研究员，他将在波士顿儿童医院（CHB）血液学/肿瘤学部著名干细胞生物学家伦纳德Zon博士的实验室进行研究项目。考夫曼博士在研究小鼠和人类表皮转录调控机制的基础上，将他的科学和技术培训扩展到使用斑马鱼模型研究黑素细胞和神经嵴的谱系调控。Zon博士经过验证的指导，加上CHB和附属机构研究社区提供的严格和培育的科学环境，为考夫曼博士在获奖期间作为研究员和过渡到独立研究员的成功提供了最大的机会。

DESCRIPTION (provided by applicant): Melanocytes are pigment-producing cells in the skin that arise from multipotent neural crest cells. The specification of melanocytes requires the activity of a transcription factor called micropthalmia-associated transcription factor (Mitf). In addition to directing formation of melanocytes, the normal functions of Mitf are also linked as a lineage oncogene to the abnormal properties of melanoma. This proposal aims to better understand how to alter melanocyte lineage character and will test the hypothesis that mechanisms that disfavor formation and survival of melanocytes may also inhibit melanoma formation. The vertebrate model organism, Danio rerio (zebrafish), will be used to 1) identify chemicals that inhibit expression of mitf and thus disfavor production of melanocytes and 2) use misexpression of neural crest transcription factors to skew neural crest cells away from the melanocyte lineage or reprogram committed melanocytes to a different but related neural crest lineage (i.e. glial/Schwann cell). In the first approach, a high-throughput chemical genetic screen using ~2280 bioactive compounds is being completed to identify chemicals that specifically decrease mitf expression in developing zebrafish embryos. Compounds that reproducibly decrease mitf expression will be assayed for their effects on neural crest stem cells, precursors, and committed descendants (e.g. glial, neural, cartilage) to determine where in neural crest development each acts. Based on the likely mechanism of action of mitf-inhibitory compounds, standard gain- and loss-of-function approaches in the zebrafish will be used to establish the regulatory mechanism(s) affecting mitf expression. In the second approach, the lineage identity of developing and committed melanocytes will be altered in zebrafish by forcing expression of transcription factors linked to the formation of the adjacent Schwann cell neural crest lineage. Transcription factors shown to skew away from melanocytes during development or to reprogram committed melanocytes will be tested in combination with the identified mitf-inhibitory compounds in a zebrafish melanoma model for their ability to prevent formation and/or cause regression of de novo melanoma tumors. Dr. Kaufman is a clinical fellow in adult oncology at the Dana Farber Cancer Institute (DFCI) and will perform his research project in the laboratory of noted stem cell biologist, Dr. Leonard Zon, in the Division of Hematology/Oncology at the Children's Hospital Boston (CHB). Building on his experience studying mechanisms of transcriptional regulation in the epidermis in mice and humans, Dr. Kaufman will expand his scientific and technical training to studies of lineage regulation in melanocytes and the neural crest using the zebrafish model. Dr. Zon's proven mentorship coupled with the rigorous and nurturing scientific environment offered by the research community at CHB and affiliated institutions offer the maximal opportunity for Dr. Kaufman's success during the award period as a fellow and in his transition to an independent investigator.