Assessing the risk of UV-induced skin cancer via non-invasive epidermal sampling

 描述(申请人提供)：这项研究的目标是开发一种从皮肤中采样DNA的方法，以评估紫外线诱发皮肤癌的风险。我们的目标是建立非侵入性的皮肤生物标记物样本，用于各种系统性和皮肤病。在这里，我们将重点测量紫外线诱导的DNA突变，这些突变与所有皮肤癌有关，包括非黑色素瘤皮肤癌和黑色素瘤。我们的中心假设是，对临床正常皮肤的DNA进行非侵入性收集和突变分析与皮肤癌的风险水平相关。我们将使用我们的新方法在紫外线诱导的皮肤癌小鼠模型中证明这一点。我们的具体目标是：具体目标1：优化超声波辅助皮肤DNA采样。我们将首先评估最佳的超声波(强度、占空比和暴露时间)和微磨皮参数(接触粗糙度和振荡频率)，以最大限度地从皮肤中提取DNA总量。我们还将优化采样介质(用于将机械能耦合到皮肤上的液体)的化学，以使用从四种类型(阳离子、阴离子、两性和非离子表面活性剂)中选择的表面活性剂组合库来最大化收集DNA的数量和稳定性。我们的目标是每平方英尺至少收获5微克DNA。并确保其稳定性(&gt；80%)4小时。具体目标2：评价抽样过程的安全性。我们将对采样的皮肤进行详细的组织病理学评估，以确定超声波对皮肤结构的影响。采样后皮肤恢复动力学的研究 被评估。我们的目标是根据组织学在7天内恢复皮肤。具体目标3：验证皮肤中紫外线突变负荷作为皮肤癌风险生物标记物的使用。使用长期紫外线照射的无毛小鼠，我们将表征在辐射后的多个时间点超声提取DNA后皮肤中紫外线信号突变的负担我们将测试从长期紫外线照射的皮肤收集的DNA是否可以用于测量DNA光产物(胸腺嘧啶二聚体)、紫外线信号损伤，特别是易感基因(TP53，HRAS，Kras，Ink4a)，以及整个外显子组的紫外线信号突变。

 DESCRIPTION (provided by applicant): The objective of this study is to develop "a methodology for sampling DNA from skin to assess the risk of UV-induced skin cancer development". Our goal is to establish non-invasive biomarker sampling from skin for a variety of systemic and cutaneous diseases. Here, we will focus on measurement of UV-induced DNA mutations that are linked to all skin cancers, both non-melanoma skin cancers and melanoma alike. Our central hypothesis is that the non- invasive collection and mutational analysis of DNA from clinically-normal skin correlates with the level of risk for skin cancer. We will demonstrate this in a mouse model of UV-induced skin cancer using our novel methods. Our specific aims are: Specific Aim 1: Optimize ultrasound-assisted sampling of DNA from skin. We will first assess the optimal ultrasound (intensity, duty cycle and exposure time) and microdermabrasion (contact roughness and oscillation frequency) parameters to maximize the total amount of DNA extracted from the skin. We will also optimize the chemistry of the sampling medium (liquid used to couple mechanical energy to the skin) to maximize the amount and stability of collected DNA using a combinatorial library of surfactants chosen from four categories (cationic, anionic, zwitterionic and non-ionic surfactants). Our goal is to harvest at least 5 ug DNA per sq. cm of skin and ensure its stability (>80%) for 4 hours. Specific Aim 2: Evaluate the safety of the sampling process. We will perform detailed histopathology assessment of sampled skin to determine the effect of ultrasound on skin structure. Recovery kinetics of skin after sampling will be assessed. Our target is recovery of skin within 7 days based on histology. Specific Aim 3: Validate the use of UV mutational load in skin as a biomarker of skin cancer risk. Using chronically UV-irradiated Hairless mice, we will characterize the burden of UV signature mutations in skin following ultrasonic DNA extraction at multiple time points following irradiation We will test whether DNA collected from chronically UV-exposed skin by ultrasound can be used to measure the UV-induced mutation burden in terms of DNA photoproducts (thymine dimers), UV signature lesions in particular susceptible genes (Tp53, Hras, Kras, Ink4a), and UV signature mutations across the entire exome.