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Impact of MC1R Functional Variants on the DNA Damage Response of Human Melanocyte

MC1R 功能变异对人黑素细胞 DNA 损伤反应的影响

基本信息

批准号：
8462256
负责人：
ZALFA ABDEL-MALEK
金额：
$ 31.83万
依托单位：
UNIVERSITY OF CINCINNATI
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-07-20 至 2015-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8462256
关键词：
8-hydroxy-2&apos -deoxyguanosine ATF2 gene Affect Alleles Animal Model Antioxidants Apoptosis Binding Biological Biological Assay Biopsy CDK4 gene Cells Clinic Clinical Code Corticotropin Cyclic AMP DNA Damage DNA Repair DNA Repair Gene Data Deoxyguanosine Development ERCC1 gene Early Diagnosis Endothelin-1 Enzymes Epidemiologic Studies Etiology Experimental Models Exposure to Failure Fibroblast Growth Factor 2 Gene Expression Gene Targeting Generations Genes Genetic Variation Genome Stability Genotype Glutathione S-Transferase Goals Hair Health Heterozygote Human Incidence Individual Knowledge Laboratories Lead Ligand Binding Link MAPK14 gene MAPK3 gene MAPK8 gene Maintenance Measures Mediating Melanocyte stimulating hormone Melanogenesis Mitogen Activated Protein Kinase 1 Mitogen-Activated Protein Kinases Molecular Genetics Monophenol Monooxygenase Mus NAD(P)H dehydrogenase (quinone) 1, human NADP Nucleotide Excision Repair Oxidative Stress POMC gene Pathway interactions Patients Phenotype Phosphorylation Physiological Pigmentation physiologic function Population Predisposition Prevention Prevention strategy Principal Investigator Property Pyrimidine Dimers Reactive Oxygen Species Receptor Gene Receptor Signaling Recording of previous events Regulation Research Research Personnel Resources Response Elements Risk Risk Assessment Risk Factors Role SAPK Signal Pathway Signal Transduction Skin Skin Cancer Skin Substitutes Skin tanning Staining method Stains Sunburn Susceptibility Gene Transfection Translating UV induced UV induced DNA damage UV response Ultraviolet Rays Variant XPA gene activating transcription factor advanced disease alpha-Melanocyte stimulating hormone annexin A5 base cancer risk caspase-3 clinical application clinical phenotype cohort common cellular transcription factor ATF effective therapy eumelanin gene function heme oxygenase-1 improved innovation irradiation loss of function melanocortin receptor melanocyte melanoma mitogen-activated protein kinase p38 novel outcome forecast oxidative DNA damage paracrine patient population peroxiredoxin I photoprotection prevent receptor receptor binding receptor function reconstitution repaired research study response restoration skin cancer prevention transcription factor transcription factor USF ultraviolet damage ultraviolet irradiation

项目摘要

DESCRIPTION (provided by applicant): The melanocortin 1 receptor gene (MC1R) is a main contributor to the diversity of human pigmentation. The activated MC1R stimulates eumelanin synthesis, and enhances nucleotide excision repair and antioxidant responses in UV-irradiated human melanocytes, thus reducing the risk for melanoma. Functional variants of MC1R disrupt receptor function and alter the pigmentary phenotype by varying extents. We propose to investigate the hypothesis that MC1R functional variants increase melanoma risk by disrupting MC1R signaling, leading to impaired UV-induced DNA damage response of human melanocytes via compromising their DNA repair, antioxidant and melanogenic capacities. The effects of most MC1R variants on the function of the melanocyte are poorly understood. Given the lack of an appropriate animal model for human pigmentation, the unique properties of the human MC1R, and the role of human melanocytes in photoprotection, it is critical to investigate the impact and establish causality of common human MC1R variants in the aberrant UV response, using human melanocytes that naturally express this gene and are a physiological target for melanocortins. A unique resource available to us is a cohort of patients with known MC1R genotype, pigmentary phenotype, and clinical history and risk factors for melanoma, which will allow us to correlate the MC1R genotype with phenotype. Melanocyte cultures will be established from skin biopsies taken from these patients. A major strength of this application is the complementary expertise of the Principal Investigators, Dr. Abdel-Malek, a pioneer in the research on melanocortins and human pigmentation, and Dr. Leachman, an expert in the molecular, genetic, and clinical aspects of melanoma, and the unique expertise of the co-Investigators and collaborators. Three Specific Aims are proposed to link the function of the MC1R to its main signaling pathway, the cAMP pathway, and to the UV-induced MAP kinase pathway, which regulates critical biological endpoints that determine melanomagenesis, namely DNA repair, antioxidant defenses and melanogenesis. In Specific Aim 1, we will compare how specific MC1R variants affect MC1R function by reducing ligand binding and/or signaling by failure to increase cAMP synthesis that activates the main signaling pathway for melanocortins. In Specific Aim 2, we will investigate in UV-irradiated melanocytes the impact of different MC1R variants on the MAP kinases and three of their downstream transcription factors NRF2, ATF2 and USF-1 that regulate the expression of antioxidant genes, DNA repair and apoptosis genes, and the pigmentary genes POMC, MC1R, and tyrosinase, respectively. In Specific Aim 3, we will determine how different MC1R variants expressed in human melanocytes affect the UV-induced levels and repair rates of cyclobutane pyrimidine dimers and 8-hydroxy-deoxyguanosine, generation of reactive oxygen species, and stimulation of melanogenesis in cultured melanocytes and skin substitutes. These studies will improve risk assessment of melanoma susceptible individuals and development of effective strategies for melanoma prevention and early detection.

描述(申请人提供)：黑素皮质素1受体基因(MC1R)是人类色素沉着多样性的主要贡献者。激活的MC1R刺激真黑素的合成，并增强紫外线照射的人黑素细胞的核苷酸切除修复和抗氧化反应，从而降低黑色素瘤的风险。MC1R的功能变异在不同程度上扰乱了受体的功能，改变了色素表型。我们提出的假设是，MC1R功能变异通过扰乱MC1R信号，通过损害人黑素细胞的DNA修复、抗氧化和黑素生成能力，导致紫外线诱导的DNA损伤反应减弱，从而增加黑色素瘤风险。大多数MC1R变异体对黑素细胞功能的影响知之甚少。鉴于人类色素沉着缺乏合适的动物模型，人类MC1R的独特性质，以及人类黑素细胞在光保护中的作用，利用自然表达该基因的人黑素细胞作为黑素皮质素的生理靶点，研究人类常见的MC1R变体在异常紫外线反应中的影响并建立因果关系是至关重要的。我们唯一可用的资源是一组已知MC1R基因、色素表型、临床病史和黑色素瘤风险因素的患者，这将使我们能够将MC1R基因与表型联系起来。黑素细胞培养将从这些患者的皮肤活检中建立。这一应用的一个主要优势是首席研究员Abdel-Malek博士(黑素皮质素和人类色素沉着研究的先驱)和Leachman博士(黑色素瘤的分子、遗传和临床方面的专家)的互补专业知识，以及共同研究人员和合作者的独特专业知识。有三个特定的目的将MC1R的功能与其主要的信号通路cAMP通路和紫外线诱导的MAP激酶通路联系起来，MAP激酶通路调节决定黑色素瘤发生的关键生物终点，即DNA修复、抗氧化防御和黑素生成。在特定的目标1中，我们将比较特定的MC1R变体如何通过减少配体结合和/或通过未能增加激活黑素皮质素主要信号通路的cAMP合成来减少信号转导而影响MC1R功能。在特定的目标2中，我们将研究不同的MC1R变异体对MAP激酶及其下游的三个转录因子NRF2、ATF2和USF-1的影响，这些转录因子分别调控抗氧化基因、DNA修复和凋亡基因以及色素基因POMC、MC1R和酪氨酸酶的表达。在具体目标3中，我们将确定在人类黑素细胞中表达的不同MC1R变体如何影响紫外线诱导的环丁烷嘧啶二聚体和8-羟基脱氧鸟苷的水平和修复率、活性氧的产生以及对培养的黑素细胞和皮肤替代物黑素生成的刺激。这些研究将改进对黑色素瘤易感个体的风险评估，并制定有效的黑色素瘤预防和早期发现策略。