Regulators of Melanocyte and Melanoma Cell Identity

描述（由申请人提供）：黑色素细胞是皮肤中产生色素的细胞，由多能神经嵴细胞产生。黑素细胞的形成需要一种称为小眼病相关转录因子（Mitf）的转录因子的活性。除了指导黑色素细胞的形成外，Mitf的正常功能也作为一种谱系致癌基因与黑色素瘤的异常特性有关。本研究旨在更好地理解如何改变黑素细胞谱系特征，并将验证不利于黑素细胞形成和存活的机制也可能抑制黑色素瘤形成的假设。脊椎动物模型生物Danio rerio（斑马鱼）将用于1)鉴定抑制mitf表达的化学物质，从而不利于黑素细胞的产生；2)利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，或将已承诺的黑素细胞重编程为不同但相关的神经嵴谱系（即胶质/雪旺细胞）。在第一种方法中，使用约2280种生物活性化合物进行高通量化学遗传筛选，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。可重复降低mitf表达的化合物将被检测其对神经嵴干细胞、前体和承诺后代（如胶质细胞、神经细胞、软骨细胞）的影响，以确定每种化合物在神经嵴发育中的作用。基于mitf抑制化合物可能的作用机制，斑马鱼的标准功能增益和功能丧失方法将用于建立影响mitf表达的调节机制。在第二种方法中，在斑马鱼中，通过强迫与相邻雪旺细胞神经嵴谱系形成相关的转录因子的表达，发育和承诺的黑素细胞的谱系身份将被改变。研究人员将在斑马鱼黑色素瘤模型中，结合已鉴定的mitf抑制化合物，测试转录因子在黑色素细胞发育过程中偏离黑色素细胞或重新编程黑色素细胞的能力，以防止黑色素瘤肿瘤的形成和/或导致新生黑色素瘤肿瘤的消退。Kaufman博士是Dana Farber癌症研究所（DFCI）的成人肿瘤学临床研究员，他将在波士顿儿童医院（CHB）血液学/肿瘤学部门著名干细胞生物学家Leonard Zon博士的实验室进行他的研究项目。基于他在小鼠和人类表皮中转录调节机制的研究经验，考夫曼博士将把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节。Zon博士的指导和CHB及其附属机构的研究社区提供的严格和培育的科学环境，为Kaufman博士在奖励期间作为研究员和过渡到独立研究者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.