Dissecting Phenotype Switching in Early Stage Melanomas

项目摘要 黑色素瘤仍然是一种毁灭性的癌症。早期黑色素瘤是大多数黑色素瘤 在美国进行诊断和管理。越来越清楚的是，转移性传播和播种 发生在肿瘤进展的非常早期，此时肿瘤仍局限于皮肤，没有其他迹象 器官受累。为了有效地与这种疾病作斗争，我们必须了解 生物学上早期肿瘤，特别是宿主对肿瘤细胞的防御机制。中国的基础研究 早期黑色素瘤在过去几十年中没有取得重大进展，主要是由于缺乏小鼠 模拟早期疾病的系统。黑色素瘤基因工程小鼠模型代表了许多 缺点，充其量模仿小鼠免疫内晚期侵袭性肿瘤(小鼠基因组) 系统。在这项提议中，我们将在新的活体人源化小鼠模型中模拟早期恶性状态 我们已经开发出用人CD34造血细胞重组高度免疫缺陷小鼠的方法 干细胞，并与人类黑色素瘤细胞的HLA-A等位基因匹配的挑战。紫外线(UVB/A) 辐射，我们将诱发更多的突变，就像在人类皮肤中一样，并研究肿瘤的进展 在时间和空间中成长。我们的初步研究表明，转录转换发生在 肿瘤细胞，它伴随着独特的宿主免疫反应，这种串扰决定了 肿瘤朝着进展或消除的方向发展。干扰素刺激物-信号一旦被激活 黑色素瘤细胞获得侵袭性表型，提示在肿瘤进展中起作用。在这里，我们 建议建立非侵袭性黑色素瘤转变为 将直接影响临床实践的侵略性表型。我们将调查：1)肿瘤内的变化 (突变，途径)在早期免疫微环境(细胞谱系，信号)内共同出现 使用人源化小鼠模型的疾病进展(Aim1)，2)在存在的情况下的亲肿瘤或抗肿瘤反应 或在利用人源化小鼠和3D皮肤模型的早期疾病中没有刺痛激活(目标1)， 3)通过调节免疫细胞亚群逆转表型和检验因果关系(目标2)和4) 开发和验证一种应用于早期黑色素瘤预测生存的预后分析(目标3)。 该项目的成功完成有望为黑色素瘤(和癌症)领域带来新的模型系统 这使得研究人类肿瘤和人类免疫系统的相互作用成为可能。IF在早期阶段提供了一个重大飞跃 黑色素瘤研究，并通过揭示新的肿瘤细胞内在或外在加深我们的理解 疾病发展的机制。

Project Summary Melanoma continues to be a devastating cancer. Early stage melanomas represent the majority of melanomas that are diagnosed and managed in the US. It is becoming clearer that metastatic dissemination and seeding occurs very early during tumor progression while the tumor is still localized to the skin without signs of other organ involvement. To effectively battle with this disease we must understand the molecular underpinnings of biologically early tumors, in particular host defense mechanisms against the tumor cells. Basic research in early melanomas has not made significant progress over the past decades mostly due to lack of murine systems that model early disease. Genetically engineered murine models of melanoma represent many shortcomings, and at best they mimic late aggressive tumors (murine genome) within the mice immune system. In this proposal, we will mimic early malignant states in novel in vivo humanized murine models that we have developed, in which highly immune deficient mice are reconstituted with human CD34+ hematopoietic stem cells and challenged with HLA-A allele-matched human melanoma cells. By ultraviolet (UVB/A) irradiation, we will induce additional mutations as in human skin, and study the progression of tumors as they grow in time and space. Our preliminary studies indicate that a transcriptional switch occurs within the tumor cells, it accompanies unique host immune responses, and this crosstalk dictates the fate of the tumor towards progression or elimination. Stimulator of interferon – STING – signaling gets activated once melanoma cells acquire an aggressive phenotype suggesting a role during tumor progression. Here, we propose to establish paradigm-shifts in the concept of non-aggressive melanomas transitioning into an aggressive phenotype that will directly impact clinical practice. We will investigate: 1) changes within the tumor (mutations, pathways) that co-occur within the immune microenvironment (cell lineages, signals) during early disease progression using humanized mouse models (Aim1), 2) pro- or anti-tumor responses in the presence or absence of STING activation in early disease leveraging the humanized mouse and 3D skin models (Aim 1), 3) reversal of phenotypes and testing causality by modulating immune cell subpopulations (Aim 2), and 4) development and validation of a prognostic assay applied to early melanomas that predicts survival (Aim 3). Successful completion of this project promises to bring new model systems to the melanoma (and cancer) field that enable studying human tumor and human immune system interactions. If offers a major leap in early stage melanoma research, and deepens our understanding by revealing new tumor cell intrinsic or extrinsic mechanisms of disease progression.