Malignant melanoma studies using iPS derived melanocytes and Zebrafish

 描述(申请人提供)：癌症的特征是不受限制的、自我更新的细胞，最终形成肿瘤，剥夺健康组织的资源。尽管是以一种受控的方式，自我更新的能力是由多能干细胞共享的，并且在成人中自然地呈现出祖细胞。这种共同的自我繁殖能力导致了一种假设，即祖细胞可能更容易转化为癌症，或者更容易转化为不同的肿瘤表型。在多种肿瘤类型中工作(横纹肌肉瘤、透明细胞肉瘤等)证实了这一假设，而脑癌的结果与此相矛盾。其他实验室最近的研究证实，成年人的表皮中存在多潜能的黑素细胞前体细胞，这为黑色素瘤的起源提供了可能性，这种细胞的分化程度更高，分化程度更低。揭示起源细胞的重要性将检验这样一种假设，即黑色素瘤发生的细胞决定了其随后的临床行为；为基于起源细胞而不仅仅是群体治疗恶性黑色素瘤提供了见解。为了解决起源细胞的分化状态对黑色素瘤的影响，本研究将利用两个互补的系统：来自iPS细胞的人黑素细胞和转基因斑马鱼黑色素瘤模型。我们已经制定了一种强大的、可重复的方案，用于通过人类多能细胞的黑素细胞前体细胞生产有色黑素细胞。我们将在特定的分化阶段引入致癌突变(包括BRAFV600E)，并表征体外和体内的致瘤表型。为了补充人类细胞培养工作，我们将利用已建立的体内斑马鱼黑色素瘤模型来推动细胞在每个祖细胞阶段的肿瘤形成。通过在谱系特异性基因启动子下表达BRAFV600E，我们可以质疑体内起源细胞的分化状态对黑色素瘤表型的重要性。

 DESCRIPTION (provided by applicant): Cancer is characterized by unrestricted, self-renewing cells, eventually forming tumors that deprive healthy tissues of resources. Albeit in a controlled fashion, the ability to self-renew is shared by pluripotent stem cells and naturally present progenitors in the adult. This shared ability to self-propagate led to the hypothesis that progenitor cells may be more apt to transformation into cancer or apt to transform with distinct tumor phenotypes. Work in several tumor types (rhabdomyosarcoma, clear cell sarcoma, etc.) has confirmed the hypothesis, while results in brain cancer contradict. Recent work by other labs has established the presence of multipotent melanocyte progenitors within the epidermis of adult humans, opening up the possibility for melanoma genesis from a more pluripotent and less differentiated cell. Uncovering the importance of cell of origin will test the hypothesis that the ell in which melanoma arises dictates its subsequent clinical behavior; providing insights on treating malignant melanomas based on their cell of origin and not just the bulk population. To address the impact of the differentiation status of the cell of origin on melanoma this study will utilize two complementary systems: human melanocytes derived from iPS cells and a transgenic zebrafish model of melanoma. We have generated a robust and repeatable protocol for the production of pigmented melanocytes via melanocyte progenitors from human pluripotent cells. We will introduce oncogenic mutations (including BRAFv600e) at defined stages of differentiation and characterize the tumorigenic phenotypes both in vitro and in vivo. To complement the human cell culture work, we will utilize the well-established in vivo zebrafish melanoma model to drive tumorigenesis in cells at each progenitor stage. By expressing BRAFv600e under promoters for lineage specific genes we can query the importance of differentiation status of the cell of origin on melanoma phenotypes in vivo.