Characterization of DNA repair in genomic and transcriptomic evolution of early lung carcinogenesis

项目摘要/摘要 肺癌仍然是美国癌症相关死亡的主要原因，尤其是 在美国退伍军人中存在问题，他们患肺癌的风险增加，导致大约5500人 每年过多的退伍军人死亡人数。这在很大程度上是由于肺癌诊断的晚期。然而， 切除癌前病变和I期非小细胞肺癌(NSCLC)可治愈大多数患者。 目前的建议包括通过低剂量计算机筛查高危肺癌患者 胸部断层扫描(CT)，死亡率相对降低20%。然而，关于 最有可能从这种干预中受益的患者群体。癌前病变，如不典型 腺瘤性增生和早期肺腺癌在胸部CT上常被诊断为结节。 与良性结节难以区分，良性结节可能导致积极的诊断和治疗干预， 对于良性结节的患者或非小细胞肺癌患者的延迟诊断，也可能是有害的。更好的诊断 需要治疗靶点来检测和治疗癌前病变和早期非小细胞肺癌 治愈是有可能的。更好地理解从癌前病变向坦率转化的潜在机制 恶性非小细胞肺癌对于更准确和及时的诊断和最终 提高了存活率。 基因组不稳定是癌症的一个标志，DNA修复途径的改变与癌症有关 增加患肺癌的风险。DNA修复蛋白C组着色性干皮病(XPC)基因 慢性吸烟使小鼠的XPC表达降低，而在人类早期和经常发现低XPC。 肺腺癌。我们的实验室发现了XPC在防止发育中的关键作用 吸烟和致癌物导致的肺腺癌的发生。我们最近发现XPC 对NTCU诱导的小鼠肺鳞状细胞癌组织学进展的保护作用。我们的预赛 数据表明，在XPC基因缺陷小鼠中致癌物质诱导的肺癌的进展与 组织学分级越高，复制基因组的复杂性越高。 基于这些发现，我们假设XPC导致DNA修复减少导致癌前病变 具有预测进展为肺癌的特征的突变和表观遗传学特征的病变。我们 建议使用癌前和早期非小细胞肺癌标本的人类样本，从三个方面研究这一问题 补充我们完善的，XPC缺陷的氨基甲酸乙酯肺腺癌进展模型。在AIM 1、我们将确定XPC在癌前病变向早、晚期腺癌病理转变过程中的作用 通过对从乌拉坦治疗的XPC缺陷小鼠分离的样本进行单细胞测序来分级， 并使用存档的基因组数据确认人类的同源变化(NCBI基因表达总览) 和机械性的体外研究。在目标2中，我们将确定免疫逃避对肺的机制影响。 在我们的小鼠肺腺癌进展模型中，使用PD-L1抑制剂阿替唑珠单抗致癌，以及 确定耐阿唑珠单抗的肺腺癌的免疫表型特征。最后， 在目标3中，我们将确定DNA修复对癌前病变关键基因组和表观遗传学变化的影响。 和早期人类肺鳞状细胞癌。DNA修复能力，由宿主细胞重新激活决定 检测，将比较支气管上皮细胞异型增生消退或持续，以及克隆性基因组和 研究了进展/持续与退化的发育不良样本的转录差异。正在研究的 早期非小细胞肺癌发育的机制和基因组不稳定性可能允许更早的识别和新的 早期非小细胞肺癌的治疗靶点。

Project Summary/Abstract Lung cancer remains the leading cause of cancer-related mortality in the United States and is particularly problematic in U.S. veterans, who are at an increased risk for lung cancer resulting in approximately 5,500 excess veteran deaths per year. This is largely due to the late stage at which lung cancer is diagnosed. However, resection of pre-malignant and stage I non-small cell lung cancers (NSCLC) results in cure in most patients. Current recommendations include screening high-risk patients for lung cancer by low dose computed tomography (CT) of the chest due to a 20% relative risk reduction in mortality. However, debate exists on the patient population most likely to benefit from this intervention. Pre-malignant lesions such as atypical adenomatous hyperplasia and early lung adenocarcinomas, identified as nodules on chest CT, are often indistinguishable from benign nodules, which can lead to aggressive diagnostic and therapeutic interventions, and possibly harm, in patients with benign nodules or delayed diagnosis in those with NSCLC. Better diagnostic and therapeutic targets are needed to detect and treat pre-malignant and early non-small cell lung cancers when cure is likely. A better understanding of the mechanisms underlying transition from pre-malignant to frankly malignant non-small cell lung cancers is essential for more accurate and timely diagnosis and ultimately improved survival. Genomic instability is a hallmark of cancer, and altered DNA repair pathways have been associated with increased risk of lung cancers. The DNA repair protein, Xeroderma Pigmentosum Group C (XPC) gene expression is decreased by chronic cigarette smoke in mice, and low XPC is identified early and often in human lung adenocarcinomas. Our laboratory has discovered a critical role of XPC in protection against development of cigarette smoke and carcinogen-induced lung adenocarcinoma development. We recently found that XPC protects against histologic progression of mouse NTCU-induced lung squamous cell carcinomas. Our preliminary data suggests progression of carcinogen-induced lung cancers in XPC deficient mice is associated with increasing copy genomic complexity with higher histologic grade. Based on these findings, we hypothesize that decreased DNA repair by XPC leads to pre-malignant lesions with characteristic mutational and epigenetic signatures that predict progression to lung cancer. We propose to study this in three aims, using human samples of pre-malignant and early NSCLC specimens complemented by our well-established, XPC-deficient urethane lung adenocarcinoma progression model. In Aim 1, we will identify the impact of XPC in transition from pre-malignant to early and late adenocarcinoma pathologic grades by performing single cell sequencing on specimens isolated from urethane-treated XPC deficient mice, and confirm orthologous changes in humans using archived genomic data (NCBI Gene Expression Omnibus) and mechanistic in vitro studies. In Aim 2, we will determine the mechanistic impact of immune evasion on lung carcinogenesis using PD-L1 inhibitor, atezolizumab, in our mouse lung adenocarcinoma progression model, and define characteristic immunogenotypic characteristics of atezolizumab-resistant lung adenocarcinomas. Finally, in Aim 3, we will determine the impact of DNA repair on critical genomic and epigenetic changes in pre-malignant and early human lung squamous cell carcinomas. DNA repair capacity, determined by host cell reactivation assay, will be compared to bronchial epithelial cell dysplasia regression or persistence, and clonal genomic and transcriptomic differences studied in dysplastic samples which progressed/persisted vs regressed. Studying the mechanisms and genomic instability in early NSCLC development may allow for earlier recognition and novel therapeutic targets in early non-small cell lung cancer.