Influence of Melanocyte Differentiation State on Melanoma Susceptibility

黑色素细胞分化状态对黑色素瘤易感性的影响

基本信息

批准号：
10204710
负责人：
Miriam Doepner
金额：
$ 4.6万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-15 至 2023-07-14
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10204710
关键词：
3-Dimensional AKT Signaling Pathway African American Architecture Binding Biology Caucasians Cells Cessation of life Clinical Coupled Data Disease Doctor of Philosophy Dopa Dopamine Dose Exhibits Exposure to G alpha q Protein G-Protein-Coupled Receptors Glutamate Receptor Growth Human Human Genome Immunotherapy Incidence Intrinsic factor Light MAP Kinase Gene Malignant - descriptor Mediating Medical Melanins Melanoma Cell Metastatic Melanoma Modeling Modernization Monophenol Monooxygenase Mus North Carolina Oncogenes PI3K/AKT Pathway interactions Patients Pharmacology Phenotype Phenylthiourea Pigments Predisposition Prevention Production Proto-Oncogene Proteins c-myc Radiation induced damage Risk Role SCID Mice Signal Transduction Signaling Molecule Site Skin Skin Cancer Skin Pigmentation Testing The Sun Time Tissues Translating Ultraviolet Rays United States Universities Work Xenograft procedure eumelanin experimental study genetic approach in vivo in vivo Model inhibitor/antagonist melanocyte melanoma metabotropic glutamate receptor 5 new therapeutic target novel therapeutics protective factors receptor stem cell biomarkers targeted treatment transcriptome sequencing tumor initiation tumor progression tumorigenesis tumorigenic ultraviolet ultraviolet damage

项目摘要

Project Summary: Melanoma is the most lethal skin cancer with over 90,000 new cases in United States each year. The risk of developing melanoma is substantially greater for people with lightly pigmented skin (1:38 in the US) than those with darkly pigmented skin (1:1000 in the US). Although this discrepancy is generally attributed to the physical UV shielding effect of melanin pigment, the sun protective factor (SPF) of melanin is only 2-3, which seems insufficient to explain the 40-fold difference of melanoma incidence in darkly and lightly pigmented skin. Our preliminary data show that primary human melanocytes (MCs) from lightly pigmented skin produce less melanin relative to primary MCs from dark skin, and this is associated with a decreased MC differentiation state and increased proliferative capacity. Additionally, the proliferation and differentiation differences between light and dark MCs persist upon transformation of primary MCs with medically relevant melanoma drivers (BRAFV600E, CDK4R24C, P53R248W, and hTERT). To test if these differences translated into different melanoma phenotypes in vivo, I engineered architecturally faithful 3-D human skin and orthotopically xenografted the tissue on SCID mice. My preliminary data show that transformed light MCs form early melanomas, whereas transformed dark MCs do not. This observation led us to question whether this stark difference was mediated by melanin synthesis itself, or by intermediates of melanin synthesis, such as dihydroxyphenylalanine (DOPA). We found that darkly pigmented MCs contain approximately 300% more DOPA, as compared to light MCs. Previous work along with my preliminary data show that DOPA serves as a signaling molecule and inhibits proliferation. Specifically, I found that exogenously supplied DOPA induces melanin synthesis in light MCs and melanoma cells, but has no effect on primary dark MC, which likely contain saturating levels of endogenously produced DOPA. The mechanism(s) of the DOPA anti-proliferative effect are currently unknown, but my preliminary data show that DOPA inhibits canonical Gq GPCR pathways leading to a decrease in MAPK and PI3K/AKT signaling pathways. In a collaborative effort with Dr. Bryan Roth at the University of North Carolina, we conducted a functional screen to test whether DOPA binds to any of the ~320 non-olfactory GPCRs in the human genome. The top hit was the Gq-coupled metabotropic glutamate receptor 5 (GRM5), which is a known melanoma driver. Aim 1 will focus on determining the mechanism of DOPA’s anti-proliferative effect, by specifically focusing on its inhibitory role of GRM5, or other top hits from our GPCR screen. Additionally, I determined that DOPA inhibits growth of medically relevant syngeneic BRaf-driven melanoma in vivo. Aim 2 seeks to further understand the endogenous and exogenous roles of DOPA in melanoma inhibition in medically-relevant melanoma models in vivo. Together, these aims will help to define the underexplored melanoma pathobiology responsible for increased melanoma in lightly pigmented people, and may identify new therapeutic targets to benefit melanoma patients.

项目摘要：黑色素瘤是最致命的皮肤癌，每年在美国有超过90,000例新病例。风险对于易于小猪的皮肤（美国1:38）的患者比那些比那些的黑色素瘤要大得多皮肤黑暗（在美国1：1000）。尽管这种差异通常归因于物理黑色素色素的紫外屏蔽作用，黑色素的太阳保护因子（SPF）仅为2-3，似乎不足以解释黑色黑色素瘤的40倍差异，黑暗和淡淡的皮肤。我们的初步数据表明，淡色皮肤的原代人黑色素细胞（MC）产生的产生较少黑色素相对于深色皮肤的主要MC，这与MC差异下降有关状态和增加的增殖能力。另外，之间的增殖和分化差异在具有医学相关的黑色素瘤驱动因素的主要MC转换时，光线和黑暗MC持续存在（BRAFV600E，CDK4R24C，P53R248W和HTERT）。测试这些差异是否转化为不同的黑色素瘤在体内表型，我设计了建筑忠实的3-D人类皮肤和原位异种移植 SCID小鼠的组织。我的初步数据表明，变化的光MC形成了早期的梅洛马斯，而变换的黑暗MC没有。这种观察结果使我们质疑这种鲜明的差异是否是介导的通过黑色素合成本身或黑色素合成的中间体，例如二羟基苯丙氨酸（DOPA）。我们发现，与LIGHT MC相比，黑暗小猪的MC含有大约300％的DOPA。以前的工作以及我的初步数据表明，DOPA用作信号分子并抑制扩散。特别是，我发现外源提供的DOPA会影响光MC中的黑色素合成和黑色素瘤细胞，但对原发性深色MC没有影响，后者可能包含饱和水平的内源性水平生产的dopa。 DOPA抗增殖作用的机制目前尚不清楚，但我初步数据表明，DOPA抑制规范GQ GPCR途径，导致MAPK和 PI3K/AKT信号通路。与北卡罗来纳大学布莱恩·罗斯博士的合作我们进行了一个功能性屏幕，以测试DOPA是否与〜320个非野战心GPCR结合人基因组。最高的是GQ耦合的代谢型谷氨酸受体5（GRM5），这是已知的黑色素瘤驱动器。 AIM 1通过特别关注其GRM5的抑制作用，或我们的GPCR屏幕上的其他最高命中。另外，我确定DOPA抑制了体内与医学相关的合成性BRAF驱动的黑色素瘤的生长。目标2 试图进一步了解多巴在黑色素瘤抑制中的内源性和外源性作用体内与医学相关的黑色素瘤模型。这些目标在一起将有助于定义未置换的黑色素瘤病理生物学负责较轻的人的黑色素瘤增加，并可能识别出新的治疗靶标可使黑色素瘤患者受益。