Regulators of Melanocyte and Melanoma Cell Identity

描述(申请人提供)：黑素细胞是皮肤中产生色素的细胞，由多能神经脊细胞产生。黑素细胞的规格需要一种称为小眼球相关转录因子(MITF)的转录因子的活性。除了指导黑素细胞的形成，MITF的正常功能也作为一种谱系癌基因与黑色素瘤的异常特性联系在一起。这项建议旨在更好地了解如何改变黑素细胞的谱系特征，并将检验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。脊椎动物模式生物Danio rerio(斑马鱼)将被用来1)识别抑制MITF表达的化学物质，从而不利于黑素细胞的产生；2)利用神经峰转录因子的错误表达来偏离黑素细胞谱系，或者将承诺的黑素细胞重新编程为不同但相关的神经峰谱系(即神经胶质/雪旺细胞)。在第一种方法中，使用~2280种生物活性化合物的高通量化学遗传筛选正在完成，以确定在斑马鱼胚胎发育中专门降低MITF表达的化学物质。可重复降低MITF表达的化合物将被检测它们对神经脊干细胞、前体和承诺的后代(例如神经胶质、神经、软骨)的影响，以确定它们在神经脊发育中的作用。基于MITF抑制化合物可能的作用机制，将利用斑马鱼中的标准获得和功能丧失的方法来建立影响MITF表达的调控机制(S)。在第二种方法中，斑马鱼正在发育和固定的黑素细胞的谱系身份将通过强制表达与形成相邻的雪旺细胞神经峰谱系有关的转录因子来改变。在斑马鱼黑色素瘤模型中，被证明在发育过程中偏离黑素细胞或对承诺的黑素细胞进行重新编程的转录因子将与已确定的MITF抑制化合物一起进行测试，以确定它们防止黑色素瘤形成和/或导致新生黑色素瘤消退的能力。考夫曼博士是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/肿瘤科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。考夫曼博士在研究老鼠和人类表皮转录调控机制的经验基础上，将把他的科学和技术培训扩展到利用斑马鱼模型研究黑素细胞和神经脊的谱系调控。Zon博士经过验证的指导，再加上CHB及其附属机构的研究社区提供的严谨和有益的科学环境，为考夫曼博士在获奖期间作为研究员取得成功以及向独立研究人员过渡提供了最大的机会。

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.