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

 描述（由申请方提供）：本研究的目的是开发“一种从皮肤中采集DNA以评估紫外线诱导皮肤癌发展风险的方法”。我们的目标是建立非侵入性的生物标志物采样从皮肤的各种系统性和皮肤疾病。在这里，我们将专注于测量与所有皮肤癌相关的紫外线诱导的DNA突变，包括非黑色素瘤皮肤癌和黑色素瘤。我们的中心假设是来自临床正常皮肤的DNA的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：优化皮肤DNA的超声辅助采样。我们将首先评估最佳超声（强度，占空比和暴露时间）和微晶磨皮（接触粗糙度和振荡频率）参数，以最大限度地提高从皮肤中提取的DNA总量。我们还将优化采样介质（用于将机械能耦合到皮肤的液体）的化学性质，以使用选自四类（阳离子、阴离子、两性离子和非离子表面活性剂）的表面活性剂组合库来最大化收集的DNA的量和稳定性。我们的目标是每平方米收获至少5 ug DNA。cm的皮肤，并确保其稳定性（>80%）4小时。具体目标2：评价取样过程的安全性。我们将对皮肤样本进行详细的组织病理学评估，以确定超声对皮肤结构的影响。采样后皮肤的恢复动力学将 进行评估。我们的目标是根据组织学在7天内恢复皮肤。具体目标3：支持使用皮肤中的紫外线突变负荷作为皮肤癌风险的生物标志物。使用长期UV照射的无毛小鼠，我们将表征在照射后的多个时间点超声DNA提取后皮肤中UV特征突变的负荷。我们将测试通过超声从长期UV暴露的皮肤收集的DNA是否可以用于测量UV诱导的突变负荷（在DNA光产物方面）。在一些实施方案中，UV标记损伤包括在特定的易感基因（Tp53、Hras、Kras、Ink4a）中的UV标记损伤，以及在整个外显子组中的UV标记突变。

 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.