Defining Transcriptional Regulators of Melanoma Initiation using Zebrafish

项目摘要/摘要 在共享致癌突变的一组易癌细胞中，有时被描述为 “癌变野”，只有选择细胞才过渡到恶性状态。由于它们的稀有性和瞬时性 癌症的发生一直很难研究，而且仍不完全清楚。中标识单元格 转化的早期阶段和了解导致其恶性的潜在机制 转换将允许更早地发现和治疗癌症，这应该会带来更好的患者 结果。皮肤就是这种情况，非癌性的黑色素细胞过度生长，称为 痣或痣含有一种名为BRAFV600E的潜在致癌突变，在超过一半的病例中也发现了这种突变 黑色素瘤癌症。然而，痣很少发展为侵袭性黑色素瘤。 为了能够研究黑色素瘤的起源和推动黑色素瘤转化为癌症的机制，我们 在斑马鱼黑色素瘤模型中开发了一种新的黑色素瘤起始报告(依赖于此 BRAFV600E突变)，在黑色素瘤第一细胞中表达荧光蛋白(EGFP)，并可 在活生生的动物身上出现。使用这一模型，我们发现胚胎神经脊身份在 黑色素瘤的启动，以及黑素细胞中Sox10神经峰转录因子水平的调节是其中之一 这一过程中的关键控制点。 在这个提议中，我们将检验这样一个假设，即正常胚胎的一个特定子集可以转录 INPUTS调节黑色素瘤起始过程中Sox10活性和神经峰转录的上调 除了Sox10的上游外，还有一些因素引导着这种向恶性转化的转变。通过定义 关键转录输入在调节Sox10中的作用，我们将了解分子 调节黑素细胞向黑色素瘤转变的机制。我们进一步确定了更多的神经脊 可能调节这一过程并确定其在黑色素瘤中的作用和调控的转录因子 入会仪式。最后，我们使用人类黑色素瘤患者来源的异种移植(PDX)来进一步阐明是否正在进行 这些因子的表达是黑色素瘤生存所必需的，或者如果它们的作用主要是在肿瘤发生过程中。 总体而言，本提案描述了确定变更的精确监管的创新方法 转录和表观遗传程序驱动黑色素瘤癌症的启动，这可能定义新的和更早的- 治疗黑色素瘤的作用靶点。

Project Summary/Abstract Within a group of cancer-prone cells that share an oncogenic mutation, sometimes described as a “cancerized field”, only select cells transition to a malignant state. Due to the rarity and transient nature of these events, cancer initiation has been difficult to study and remains incompletely understood. Identifying cells at the earliest stages of transformation and understanding the underlying mechanisms leading to their malignant conversion would allow for earlier detection and treatment of cancer, which should lead to better patient outcomes. Such is the case in the skin, where non-cancerous overgrowths of pigmented melanocytes, called nevi or moles, harbor a potentially cancer-causing mutation, termed BRAFV600E, which is also found in over half of melanoma cancers. Yet nevi rarely progress to invasive melanoma. To enable studies of melanoma initiation and the mechanisms driving this conversion to cancer, we developed a novel reporter of melanoma initiation in a zebrafish melanoma model (that relies on this same BRAFV600E mutation) that expresses a fluorescent protein (EGFP) in the first cell of melanoma and can be visualized in a live animal. Using this model, we found that embryonic neural crest identity reemerges during melanoma initiation, and that regulation of sox10 neural crest transcription factor levels in melanocytes is one key control point in this process. In this proposal, we will test the hypothesis that a specific subset of normally embryonic transcriptional inputs modulates sox10 activity during melanoma initiation and that upregulation of neural crest transcription factors -- in addition to and potentially upstream of sox10 -- directs this transition to malignancy. By defining the role of key transcriptional inputs in modulating sox10 in its native context, we will understand the molecular mechanisms modulating the melanocyte to melanoma transition. We further identify additional neural crest transcription factors that may modulate this process and determine their role and regulation in melanoma initiation. Finally, we use human melanoma patient-derived xenografts (PDX) to further clarify if ongoing expression of these factors is needed for melanoma viability or if their role is primarily during tumor initiation. Overall, this proposal describes innovative approaches to determine the precise regulation of altered transcriptional and epigenetic programs driving melanoma cancer initiation, which may define new and earlier- acting therapeutic targets for treating melanoma.