The mutational mechanisms shaping melanocytes in human skin

塑造人类皮肤黑素细胞的突变机制

• 批准号: 10581888
• 负责人: Alan Hunter Shain
• 金额: $ 42.67万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-17 至 2027-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10581888
• 关键词: Address; Affect; Aging; Anatomy; Area; Automobile Driving; Back; Base Pairing; Biological; Biological Assay; Cancer Etiology; Cataloging; Catalogs; Cell division; Cells; Chronic; Communities; Complement; Complex; DNA Damage; DNA Repair; DNA sequencing; Data; Etiology; Evolution; Exposure to; Face; Genes; Genome; Genomics; Genotype; Goals; Grant; Guide prevention; Guidelines; Head and neck structure; Human; Human body; In Vitro; Incidence; Individual; Knowledge; Laboratories; Malignant Neoplasms; Measures; Methods; Molecular; Mutagens; Mutation; Normal tissue morphology; Observational Study; Observational epidemiology; Occupational Exposure; Organ; Pattern; Periodicals; Persons; Pigments; Prevention; Prevention strategy; Process; Public Health; Radiation Induced DNA Damage; Recording of previous events; Recreation; Reporting; Research; Research Personnel; Resolution; Risk; Risk Factors; Role; Sensitivity and Specificity; Shapes; Shoulder; Site; Skin; Skin Cancer; Somatic Mutation; Sun Exposure; Sunbathing; Testing; UV Radiation Exposure; UV induced; Ultraviolet Rays; cancer genomics; cancer risk; course development; epidemiology study; expectation; experience; innovative technologies; insight; melanocyte; melanoma; preneoplastic cell; prevent; repaired; the sun; tissue/cell culture; tumor; ultraviolet irradiation

Project Summary/Abstract As a barrier organ, skin forms the main defense against ultraviolet (UV) radiation, a potent mutagen emitted by the sun. The mutational damage incurred through this role can lead to melanoma, the deadliest form of skin cancer. Contrary to expectations, melanoma is more common on body sites that are only exposed to UV radiation intermittently, such as the back and shoulder, rather than body sites exposed more continuously, such as the head/neck areas. We recently reported the first catalogue of somatic mutations in melanocytes from normal human skin and discovered that melanocytes from the back/trunk had higher mutation burdens than donor-matched melanocytes from the head/neck areas. Based on our mutational observations and the anatomic patterns of melanoma, we hypothesize that melanocytes on the head/neck areas have evolved mechanisms to accumulate mutations more slowly than melanocytes from other body sites – likely an adaptation to counterbalance the higher levels of cumulative sun exposure affecting those sites. If true, this would alter prevention strategies. Moreover, a better understanding of the mechanisms by which melanocytes accumulate mutations would reveal molecular strategies to slow down this process and reduce the incidence of melanoma. We will test our hypothesis in aim 1 by comparing somatic mutations in melanocytes of different anatomic origins within-people and in aim 2 by cataloguing somatic mutations in site-matched melanocytes across people who offer detailed histories of sun exposure. These studies will offer correlative data implicating the main factors driving up the mutation burdens in melanocytes. A major obstacle to these studies is that it is difficult to measure somatic mutations in individual cells at a high degree of accuracy. However, we recently pioneered a workflow to call mutations in individual melanocytes at nearly 100% specificity and sensitivity. To complement these observational studies, in aim 3, we will measure in vitro the rates at which melanocytes of different anatomic origins repair DNA damage and dissect the main mechanisms regulating this process. Towards this goal, we have developed assays to measure UV-radiation-induced DNA damage at single base- pair resolution in tissue-cultured cells. Taken together, the scientific approaches employed in this proposal are technologically innovative and will illuminate the mutational mechanisms operating on melanocytes in normal human skin, addressing major gaps in knowledge that have vexed the skin research community.

项目总结/摘要 作为一个屏障器官，皮肤形成了对紫外线（UV）辐射的主要防御，紫外线辐射是一种由皮肤发出的强效诱变剂。 太阳通过这种作用引起的突变损伤可能导致黑色素瘤，这是最致命的皮肤形式 癌与预期相反，黑色素瘤更常见于仅暴露于紫外线的身体部位 间歇性辐射，如背部和肩部，而不是身体部位暴露更连续， 例如头部/颈部区域。我们最近报道了黑素细胞体细胞突变的第一个目录 从正常的人类皮肤中，发现背部/躯干的黑色素细胞具有更高的突变负荷， 与捐赠者匹配的黑色素细胞相比根据我们对突变的观察 黑色素瘤的解剖模式，我们假设，黑色素细胞的头部/颈部地区已经演变 突变积累比身体其他部位的黑素细胞更慢的机制--可能是一种 适应性调整，以抵消影响这些地点的累积阳光照射的较高水平。如果这是真的， 将改变预防策略。此外，更好地了解黑素细胞 积累突变将揭示减缓这一过程并减少 黑素瘤 我们将通过比较不同解剖结构的黑素细胞中的体细胞突变来检验我们在aim 1中的假设。 在人类和aim 2中的起源，通过编目位点匹配的黑素细胞中的体细胞突变， 提供详细的日照历史的人。这些研究将提供相关数据， 黑素细胞突变负担增加的主要因素。这些研究的一个主要障碍是 难以高精度地测量单个细胞中的体细胞突变。然而，我们最近 开创了一种工作流程，以接近100%的特异性和灵敏度调用单个黑素细胞中的突变。到 作为对这些观察性研究的补充，在目标3中，我们将在体外测量黑素细胞的比率， 不同的解剖起源修复DNA损伤和解剖的主要机制调节这一过程。 为了实现这一目标，我们已经开发了测定紫外线辐射诱导的单碱基DNA损伤的方法， 组织培养细胞中的配对分辨率。总的来说，这项建议所采用的科学方法是 技术创新，并将阐明突变机制的黑色素细胞在正常 人类皮肤，解决了困扰皮肤研究界的主要知识空白。