Mapping DNA Repair and Error-Prone DNA Synthesis in Geriatric Skin

绘制老年皮肤 DNA 修复和容易出错的 DNA 合成图谱

• 批准号: 10426239
• 负责人: Michael George Kemp
• 金额: --
• 依托单位: DAYTON VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-10-01 至 2026-09-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10426239
• 关键词: ATR gene; Actinic keratosis; Address; Affect; Age; Age Years; Aging; Apical; Biology; Biopsy; Caring; Cause of Death; Cell Cycle Progression; Cells; Clinic; Clinical; Colon; Colon Carcinoma; DNA; DNA Damage; DNA Repair; DNA biosynthesis; DNA mapping; DNA photoproducts; DNA-Directed DNA Polymerase; Data; Defect; Dermal; Dermatology; Development; Diagnosis; Elderly; Epidermis; Epithelium; Erythrocytes; Excision; Excision Repair; Exposure to; Failure; Fibroblasts; Financial Hardship; General Population; Genome; Genomic DNA; Genomics; Goals; Growth Factor; Healthcare Systems; Hormones; Human; In Vitro; Incidence; Individual; Injections; Insulin; Insulin deficiency; Insulin-Like Growth Factor I; Insulin-Like-Growth Factor I Receptor; Intervention; Knowledge; Lasers; Lung; Maintenance; Malignant Neoplasms; Malignant neoplasm of esophagus; Malignant neoplasm of lung; Modeling; Morbidity - disease rate; Mutagenesis; Neoplasms; Nucleotides; Organ Transplantation; Outcome; Pathogenesis; Pathway interactions; Phenotype; Phosphotransferases; Physiological; Play; Population; Production; Property; Publishing; Pyrimidine; Pyrimidine Dimers; Qualifying; Receptor Activation; Receptor Signaling; Rejuvenation; Research; Resolution; Risk Factors; Role; Signal Transduction; Skin; Skin Cancer; Skin Carcinogenesis; Skin Carcinoma; Solid; Source; Stress Response Signaling; Sun Exposure; Sunlight; Testing; Tissues; Transplant Recipients; Treatment Cost; UV Mutagenesis; UV Radiation Exposure; UV carcinogenesis; UV induced; UVB induced; Ultraviolet Rays; Veterans; Work; age related; aged; cancer initiation; cancer risk; carcinogenesis; cost; cytokine; dietary; experience; genome-wide analysis; genomic locus; human disease; improved; in vivo; innovation; keratinocyte; military veteran; mortality; novel; novel therapeutic intervention; patient population; photolesion; premalignant; prevent; programs; repaired; replication stress; response; senescence; skin disorder; skin wound; tumorigenesis; tumorigenic; ultraviolet; young adult

PROJECT SUMMARY/ABSTRACT Non-melanoma skin cancers (NMSCs) are a growing problem among our nation’s Veteran population, and current treatments are both costly and potentially disfiguring. The primary risk factors for NMSC development are exposure to ultraviolet B (UVB) wavelengths of sunlight and advanced age. Though the mutagenic effects of UVB-induced bipyrimidine dimers in genomic DNA are well known, the mechanisms by which age impacts UVB- dependent NMSC initiation in skin keratinocytes are less clear. The unique structural and physiological properties of geriatric skin likely influence both the number and distribution of photolesions that form across the genome of basal keratinocytes after UV exposure and the ways in which these cells respond to the damage. Moreover, aged tissues including skin are known to contain a higher number of senescent dermal fibroblasts than younger skin, which may alter cytokine and growth factor production and contribute to a pro-tumorigenic microenvironment. One such factor that is expressed at lower levels in geriatric skin is insulin-like growth factor 1 (IGF-1). Our published and preliminary data show that the loss of IGF-1/IGF-1 receptor (IGF-1R) signaling in epidermal keratinocytes results in UVB-irradiated keratinocytes that are unable to efficiently remove UVB photoproducts from DNA or to properly activate the apical DNA damage response kinase ATR, which functions to suppress error-prone DNA synthesis on damaged DNA templates. The objective of this proposal is to determine how age and specifically IGF-1 receptor activation affect the formation and replication of UVB DNA photoproducts in basal epidermal keratinocytes in human skin. The background of the research team, which includes expertise in DNA repair, replication stress response signaling, genomics, keratinocyte biology, and clinical dermatology, makes this group uniquely qualified to address this important clinical issue. The central hypothesis of this proposal is that the skin of geriatric individuals is prone to carry out a more mutagenic form of DNA synthesis following UVB exposure than the skin of younger individuals. This hypothesis has been derived from significant preliminary and published data with both cultured keratinocytes in vitro and human skin biopsies ex vivo and in vivo. The rationale for this proposed research is that it will define how the unique features of geriatric skin predispose it to UVB mutagenesis and carcinogenesis. Our hypothesis will be tested by carrying out the following three specific aims: Aim 1) Define how age and IGF-1 status influence UVB-induced DNA photoproduct formation and repair across the keratinocyte genome in human skin epidermis; Aim 2) Determine how IGF-1 signaling impacts the utilization of error-prone DNA polymerases in UVB-irradiated human skin explants ex vivo and cultured keratinocytes in vitro; and Aim 3) Define how subject age and IGF-1 status affect the replication of UVB-damaged DNA in human skin epidermis in vivo. Our approach is innovative because it will provide a detailed, quantitative characterization of DNA damage formation and replication in skin epidermis using novel technical approaches that have not previously been applied to human skin. The proposed research is significant to the VA because it will show how the geriatric skin microenvironment contributes to UV mutagenesis and carcinogenesis. Ultimately, we expect that the knowledge that will be gained here will provide further mechanistic rationale for the use of clinical skin rejuvenation interventions aimed at preventing NMSC in specific patient populations. Lastly, because many other cancers are associated with both advanced age and the exposure of epithelial tissues to environmental and dietary DNA damaging agents, our work likely has implications for understanding the pathogenesis of lung, colon, and esophageal cancers in older veterans.

项目总结/摘要 非黑色素瘤皮肤癌（NMSC）是我国退伍军人中日益严重的问题， 并且目前的治疗既昂贵又可能毁容。NMSC发展的主要风险因素 是暴露于紫外线B（UVB）波长的阳光和高龄。尽管 UVB诱导的基因组DNA中的双嘧啶二聚体是众所周知的，年龄影响UVB的机制， 在皮肤角质形成细胞中的NMSC依赖性起始不太清楚。独特的结构和生理特性 老年人皮肤的光损伤可能会影响整个基因组中形成的光损伤的数量和分布， 紫外线照射后的基底角质形成细胞以及这些细胞对损伤的反应方式。此外，委员会认为， 已知包括皮肤在内的老化组织含有比年轻组织更多数量的衰老真皮成纤维细胞 皮肤，其可改变细胞因子和生长因子产生并有助于促肿瘤发生 微环境。在老年皮肤中表达水平较低的一种因子是胰岛素样生长因子 1（IGF-1）。我们已发表的和初步的数据表明，IGF-1/IGF-1受体（IGF-1 R）信号转导的丧失， 表皮角质形成细胞导致UVB照射的角质形成细胞不能有效地去除UVB 光产物或适当激活顶端DNA损伤反应激酶ATR，其功能 来抑制在受损DNA模板上容易出错的DNA合成。这项建议的目的是 确定年龄和特定的IGF-1受体活化如何影响UVB DNA的形成和复制 人皮肤基底表皮角质形成细胞中的光产物。研究团队的背景， 包括DNA修复，复制应激反应信号，基因组学，角质形成细胞生物学， 临床皮肤病学，使这个小组唯一有资格解决这一重要的临床问题。中央 这一建议的假设是，老年人的皮肤易于进行更诱变的形式， UVB暴露后的DNA合成比年轻人的皮肤要多。这一假设是由 从体外培养的角质形成细胞和人类皮肤活检的重要初步和已发表的数据 离体和体内。这项拟议研究的基本原理是，它将定义如何独特的功能， 老年人皮肤易受UVB诱变和致癌作用的影响。我们的假设将通过 我们提出了以下三个具体目标：1）确定年龄和IGF-1状态如何影响UVB诱导的DNA 人皮肤表皮中角质形成细胞基因组的光产物形成和修复;目的2）确定 IGF-1信号如何影响UVB照射的人体皮肤中易错DNA聚合酶的利用 离体外植体和体外培养的角质形成细胞;和目标3）定义受试者年龄和IGF-1状态如何影响 UVB损伤DNA在人体皮肤表皮中的复制。我们的方法是创新的，因为它 将提供皮肤表皮中DNA损伤形成和复制的详细定量表征 使用以前没有应用于人类皮肤的新技术方法。拟议研究 对VA来说意义重大，因为它将显示老年皮肤微环境如何促进UV 诱变和致癌作用。最终，我们希望在这里获得的知识将提供 使用旨在预防NMSC的临床嫩肤干预的进一步机制原理， 特定的患者人群。最后，因为许多其他癌症都与高龄和 上皮组织暴露于环境和饮食DNA损伤剂，我们的工作可能已经 对了解老年退伍军人肺癌、结肠癌和食管癌发病机制的意义。