Investigating the Role of BACE2 in Melanocyte Development and Melanoma Progression

项目摘要 黑色素瘤是一种起源于黑素细胞的侵袭性皮肤肿瘤。虽然有很好的证据证明细胞 异质性在黑色素瘤中很普遍，细胞的色素沉着程度和细胞变化很大 黑色素瘤的形态、临床治疗没有考虑到这些不同的分化状态。这个 这种表型异质性背后的机制仍不清楚，但在 药物敏感性和转移能力。表型异质性的一个决定因素是分化 细胞的状态，这可能是由细胞固有的和微环境因素造成的。我们已经确定了一个 在黑色素瘤分化状态中起作用的一系列基因，包括脱落酶BACE2。在目标1中，我们 证明人类黑色素瘤强烈过度表达BACE2。使用斑马鱼BACE2-/-突变体 斑马鱼，我们证明了BACE2功能的丧失会导致黑素细胞的强制分化。这 提示BACE2是一种分化守门人，它调节神经峰之间的适当平衡 和黑素细胞状态。在目标2中，我们将通过操纵来研究分化对黑色素瘤的影响。 BACE2水平，侧重于细胞增殖和转移。我们将利用斑马鱼移植和 转基因模型，分析分化对原发肿瘤生长和转移的逐步影响。 然后，我们将通过设计具有可诱导基因敲除的黑色素瘤细胞系来将这项工作扩展到人类癌症 BACE2。这些研究将阐明参与黑素细胞分化的BACE2基因如何影响 黑色素瘤的生长和转移。 在我的博士前培训中，我将对肿瘤的异质性有更深入的了解 细胞的内在分化状态，这项培训将为我过渡到博士后研究做准备 重点研究外在肿瘤微环境如何塑造肿瘤异质性。

Project Summary Melanoma is an aggressive skin tumor arising from melanocytes. While it is well documented that cell heterogeneity is prevalent within melanomas with cells varying widely in their degree of pigmentation and cell morphology, clinical treatment of melanoma does not take into account these diverse differentiation states. The mechanisms underlying this phenotypic heterogeneity remain poorly understood, but play important role in drug sensitivity and metastatic capacity. One determinant of phenotypic heterogeneity is the differentiation state of the cell, which can be due to both cell-intrinsic and microenvironmental factors. We have identified a series of genes that play a role in melanoma differentiation state, including the sheddase BACE2. In Aim 1, we demonstrated that human melanomas strongly overexpress BACE2. Using a zebrafish BACE2-/- mutant zebrafish, we showed that BACE2 loss of function leads to enforced differentiation of melanocytes. This suggests that BACE2 is a differentiation gatekeeper that modulates the proper balance between neural crest and melanocyte states. In Aim 2, we will investigate the impact of differentiation on melanoma by manipulating BACE2 level with an emphasis on cell proliferation and metastasis. We will utilize zebrafish transplantation and transgenic models to dissect the step-wise influence of differentiation on primary tumor growth and metastasis. We will then extend this work to human cancer by engineering melanoma cell lines with inducible knockdown of BACE2. These studies will shed light on how BACE2, a gene involved in melanocyte differentiation, affects melanoma growth and metastasis. In my predoctoral training, I will gain a deeper understanding of the tumor heterogeneity resulting from cell intrinsic differentiation status, and this training will prepare me for my transition into postdoctoral research with a focus on how the extrinsic tumor microenvironment shapes tumor heterogeneity.