Epigenetic Effect of the Microenvironment on Stem Cell Plasticity and Function

描述（由申请人提供）：转移性黑色素瘤是最具破坏性的疾病之一，干细胞亚群的证据开始出现。侵袭性人类黑色素瘤细胞系和肿瘤的比较全球基因分析揭示了与多种细胞表型和前体干细胞相关的基因表达。这些发现支持了侵袭性黑色素瘤细胞恢复到多能性、可塑性表型的前提。确定肿瘤细胞可塑性分子机制的关键是阐明微环境在这一过程中所起的独特作用。最值得注意的是，我们已经生成的数据显示，多能转移性黑色素瘤细胞亚群（可能是干细胞）通过hESCs和鸡神经嵴富集区域的胚胎微环境(s)重编程为黑素细胞样表型。基于这些观察结果，我们提出验证胚胎微环境与hESCs相关的中心假设(Wa01。Wa09和UC06)和鸡神经嵴富集区(s) -包含有可能对暴露于它们的人类转移性多能黑色素瘤细胞的基因型和表型进行表观遗传重编程的信息线索。我们的长期目标是了解干细胞及其微环境之间双向通信的生物学机制，最终导致细胞命运的决定。我们的短期目标是确定暴露于特定hESC环境线索的多能转移性黑色素瘤细胞的表观遗传重编程相关的生物学和分子参数。利用独特的3-D器官型模型和鸡胚胎，结合功能分析、4-D成像、激光捕获显微解剖和表观遗传学分析，我们提出：未改变目标1：确定hESCs的3-D微环境对其重编程人类转移性多能黑色素瘤细胞基因型和表型的潜力的表观遗传学影响。修订目标2：确定暴露于各种hESC 3-D微环境下受影响的多能黑色素瘤细胞群基因型和表型表观遗传重编程的分子基础，特别关注节点信号通路。目的3：研究胚胎鸡模型中多能黑色素瘤细胞群的发育可塑性-确定参与干细胞可塑性和细胞命运决定控制以及转移表型重编程的节点信号通路的生物学相关性。总结：在这些研究完成后，我们期望对具有干细胞特性的人类胚胎和多能转移性黑色素瘤细胞的生物学特性获得新的见解，这些特性可以转化为新的治疗应用。

DESCRIPTION (provided by applicant): One of the most devastating diseases to manage is metastatic melanoma, where the evidence of stem cell subpopulations is starting to emerge. Comparative global gene analyses of aggressive human melanoma cell lines and tumors have revealed the expression of genes associated with multiple cellular phenotypes and precursor stem cells. These findings support the premise that aggressive melanoma cells revert to a multipotent, plastic phenotype. Key to identifying the molecular mechanisms underlying tumor cell plasticity is to elucidate the unique role the microenvironment plays in this process. Most noteworthy are the data we have generated showing the reprogramming of subpopulations (possibly the stem cells) of multipotent metastatic melanoma cells to a melanocyte-like phenotype by the embryonic microenvironment(s) of hESCs and chick neural crest-rich regions. Based on these observations, we propose to test the central hypothesis that the embryonic microenvironments associated with hESCs (Wa01. Wa09 and UC06) and chick neural crest-rich region(s) - contain informational cues with the potential to epigenetically reprogram the genotype and phenotype of human metastatic multipotent melanoma cells exposed to them. Our long term goal is to understand the biological mechanisms underlying the bi-directional communication between stem cells and their microenvironment(s) that ultimately result in cell fate determinations. Our short term goal is to identify the biological and molecular parameters associated with the epigenetic reprogramming of multipotent metastatic melanoma cells exposed to specific hESC environmental cues. Using unique, 3-D organotypic models and chick embryos, together with functional analysis, 4-D imaging, laser capture microdissection, and epigenetic analysis, we propose to: Unchanged Aim 1: Determine the epigenetic influence of the 3-D microenvironment(s) of hESCs for their potential to reprogram the genotype and phenotype of human metastatic multipotent melanoma cells. Revised Aim 2: Identify the molecular basis for the epigenetic reprogramming of the genotype and phenotype of the affected multipotent melanoma cell populations exposed to various hESC 3-D microenvironments, with particular focus on the Nodal signaling pathway. Revised Aim 3: Investigate the developmental plasticity of multipotent melanoma cell populations in an embryonic chick model - to determine the biological relevance of the Nodal signaling pathway involved in stem cell plasticity and the control of cell fate determination and reprogramming of the metastatic phenotype. Lay Summary: At the completion of these studies, we expect to gain new insights into the biological properties of human embryonic and multipotent metastatic melanoma cells with stem cell properties that could be translated for novel therapeutic applications.