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：
8069824
负责人：
ZALFA ABDEL-MALEK
金额：
$ 32.47万
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 2014-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8069824
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. PUBLIC HEALTH RELEVANCE: Relevance Melanoma, the most fatal form of skin cancer, represents a major clinical challenge due to the poor prognosis and absence of an effective treatment for advanced disease. The incidence of melanoma continues to increase annually, underscoring the importance of its prevention and early detection. Our long term goal is to utilize the MC1R genotype as a marker for skin cancer, particularly melanoma, susceptibility, and to target activation of the relevant MC1R pathways for skin cancer prevention, beginning with our already assembled cohort of patience. Our elucidation of the impact of different MC1R functional variants on the function of the MC1R and the response of human melanocytes to melanocortins and UV should allow us to translate our research findings into these important clinical applications.

描述（由申请人提供）：黑色素皮质素1受体基因（MC1R）是人类色素沉着多样性的主要因素。活化的MC1R刺激Eumelanin的合成，并增强紫外线染色的人黑色素细胞中的核苷酸切除修复和抗氧化反应，从而降低了黑色素瘤的风险。 MC1R的功能变体破坏受体功能，并通过改变扩展来改变色素表型。我们建议研究MC1R功能变体通过破坏MC1R信号的风险增加了黑色素瘤风险的假设，从而导致紫外线诱导的人类黑色素细胞通过损害其DNA修复，抗氧化剂和黑色素生成能力而受损。大多数MC1R变体对黑素细胞功能的影响知之甚少。鉴于缺乏适合人类色素化的动物模型，人类MC1R的独特特性以及人类黑素细胞在光保护中的作用，研究至关重使用自然表达该基因的人类黑色素细胞，是黑色素皮质素的生理靶标。我们可以使用的独特资源是一组已知的MC1R基因型，色素表型以及黑色素瘤的临床病史和危险因素的患者，这将使我们能够将MC1R基因型与表型相关联。将从这些患者的皮肤活检中建立黑色素细胞培养物。该应用的主要优势是主要研究人员的补充专业知识，Abdel-Malek博士，Abdel-Malek博士，他是黑色素皮质素和人类色素沉着研究的先驱，以及分子，遗传和临床方面的专家Leachman博士。，以及共同投资者和合作者的独特专业知识。提出了三个特定的目的，以将MC1R的功能与其主要信号通路，CAMP通路以及UV诱导的MAP激酶途径联系起来，该途径调节了确定黑色素作用的关键生物学终点，即DNA修复，抗氧化剂防御和杂物。在特定目标1中，我们将通过减少配体结合和/或信号传导来比较特定的MC1R变体如何通过不增加cAMP合成来激活黑素皮质的主要信号通路来影响MC1R功能。在特定目标2中，我们将在紫外线辐射的黑素细胞中研究不同的MC1R变体对MAP激酶的影响以及其下游转录因子NRF2，ATF2和USF-1的三个调节抗氧化基因表达，DNA修复和凋亡基因的表达，以及色素基因POMC，MC1R和酪氨酸酶。在特定目标3中，我们将确定在人类黑素细胞中表达的不同MC1R变体如何影响环丁烷嘧啶二聚体的水平和修复速率，以及8-羟基脱氧鸟苷，产生活力的反应性氧，以及对培养的梅拉素细胞和梅拉尼生成的刺激皮肤替代品。这些研究将改善黑色素瘤易感人群的风险评估，并开发预防黑色素瘤和早期检测的有效策略。公共卫生相关性：相关性黑色素瘤是皮肤癌最致命的形式，这是预后不良和缺乏有效治疗晚期疾病的主要临床挑战。黑色素瘤的发病率每年继续增加，强调了其预防和早期检测的重要性。我们的长期目标是利用MC1R基因型作为皮肤癌的标志物，尤其是黑色素瘤，易感性，并靶向相关的MC1R途径以预防皮肤癌预防皮肤癌，始于我们已经组装的耐心队列。我们阐明了不同MC1R功能变体对MC1R功能的影响以及人类黑色素细胞对黑色素皮质蛋白和紫外线的反应，应该使我们能够将我们的研究发现转化为这些重要的临床应用。