Impact of circadian disruption on pancreatic cancer development and progression

摘要 轮班工作导致的昼夜节律紊乱越来越被认为是一个主要的环境健康危害。 鉴于西方社会轮班工作的普遍性，对昼夜节律紊乱所起作用的调查 应该在许多疾病中进行评估。除了对代谢/肥胖的充分证明的作用外， 心理健康，轮班工作已被列为2A型“可能致癌物”。最近的研究表明， 环境或遗传因素对昼夜节律的破坏可促进小鼠肺癌的发生 疾病的模型。我们试图进行类似的研究，以评估昼夜节律的破坏是否会影响 胰腺癌的发展和/或进展。据估计，胰腺癌将夺走 到2021年将有近48，000人死亡，成为美国癌症相关死亡的第三大原因。 这种疾病的预后非常差，中位生存期约为8个月。这种可怕的预测 反映了诊断时疾病的晚期和胰腺癌对目前治疗的抵抗力。 采用的治疗方案，强调需要更深入地了解分子基础 疾病。这种理解将提高开发新的有效治疗策略的能力。 考虑到轮班工作的人数，了解昼夜节律紊乱是否会增强 胰腺肿瘤的发生和/或进展，并表征参与这一过程的因素是非常重要的 意义因此，这项提议将直接检验昼夜节律紊乱增强 胰腺癌的发展和进展。 在第一个具体的目标，我们将测试的假设，昼夜节律中断引起的改变照明协议 促进称为胰腺上皮内肿瘤的胰腺癌前体病变的发展 （PanIN）在经验证的FSF-KrasG 12 D; Pdx 1-flp（KF）小鼠模型中。我们将进一步评估昼夜节律是否 在该模型中，以及在FSF中，破坏促进向浸润性癌的进展， KrasG 12 D; Trp 53 FRT/+; Pdx 1-flp（KPF）模型。为了从机制上了解昼夜节律紊乱是如何促进 胰腺肿瘤发生，我们将另外进行荷瘤小鼠的代谢评估。我们将 还对一部分肿瘤进行单细胞RNA测序，以鉴定基因表达变化， 特别是与昼夜节律紊乱后诱发的肿瘤相关。 在第二个目标中，我们将检验这样一个假设，即正常昼夜节律的遗传破坏促进了 胰腺肿瘤的发生和发展。我们将产生复合基因小鼠品系， 肿瘤促进Kras和Trp 53等位基因与神经元特异性Bmal 1缺失的组合， 会扰乱正常的昼夜节律诱导的代谢和基因表达变化的平行评价 在这些小鼠中，当与Aim 1的数据相结合时，将允许对基因和途径进行稳健的鉴定。 为今后的研究确定优先次序。 总的来说，拟议的研究将阐明昼夜节律中断对胰腺癌的潜在贡献。 癌症的发展和进展。他们还将为未来的研究奠定基础， 潜在的机制，从而导致新的预防和治疗方法。

Abstract Shift work with resulting circadian disruption is increasingly recognized as a major environmental health hazard. In view of the prevalence of shift work in Western societies, investigation of the role played by circadian disruption should be assessed in many diseases. In addition to well-demonstrated effects on metabolism/ obesity and mental health, shift work has been classified as a Type 2A “probable carcinogen.” Recent work shows that environmental or genetic disruption of circadian rhythm can promote the development of lung cancer in mouse models of the disease. We seek to conduct similar studies, to assess whether circadian disruption impacts the development and/or progression of pancreatic cancer. It is estimated that pancreatic cancer will claim the lives of almost 48,000 people in 2021, making it the third-leading cause of cancer-related deaths in the United States. The disease carries a very dismal prognosis with median survival of approximately 8 months. This dire prognosis reflects the advanced stage of disease at diagnosis and the resistance of pancreatic cancer to currently employed treatment regimens, underscoring the need for a deeper understanding of the molecular underpinnings of the disease. Such understanding will increase the ability to develop novel effective therapeutic strategies. Given the number of individuals who perform shift work, understanding whether circadian disruption enhances pancreatic tumor initiation and/or progression, and characterizing the factors involved in this process is of great significance. This proposal will therefore directly test the hypothesis that circadian disruption enhances pancreatic cancer development and progression. In the first specific aim, we will test the hypothesis that circadian disruption induced by altered lighting protocols promotes the development of pancreatic cancer precursor lesions called pancreatic intraepithelial neoplasms (PanINs) in the validated FSF-KrasG12D;Pdx1-flp (KF) mouse model. We will further assess whether circadian disruption promotes progression to invasive carcinoma in this model, as well as in the FSF- KrasG12D;Trp53FRT/+;Pdx1-flp (KPF) model. To gain mechanistic insight into how circadian disruption promotes pancreatic tumorigenesis, we will additionally perform metabolic assessments of tumor-bearing mice. We will also subject a subset of tumors to single-cell RNA sequencing to identify gene expression changes that are specifically associated with tumors induced following circadian disruption. In the second aim, we will test the hypothesis that genetic disruption of normal circadian rhythms promotes the development and progression of pancreatic tumors. We will generate compound genetic mouse strains bearing the tumor-promoting Kras and Trp53 alleles in combination with neuron-specific deletion of Bmal1, previously shown to disrupt normal circadian rhythm. Parallel evaluation of metabolic and gene expression changes induced in these mice, when combined with the data from Aim 1, will allow the robust identification of genes and pathways to prioritize for future studies. Collectively, the proposed studies will elucidate the potential contributions of circadian disruption to pancreatic cancer development and progression. They will also lay the foundation for future studies that will interrogate the potential mechanisms in depth, thereby leading to novel prevention and therapeutic approaches.