Impact of circadian disruption on pancreatic cancer development and progression

摘要 轮班工作造成的昼夜节律紊乱越来越被认为是一种重大的环境健康危害。 鉴于倒班工作在西方社会的普遍存在，对昼夜节律中断所起作用的调查 应该在许多疾病中进行评估。除了对新陈代谢/肥胖的影响得到充分证明外， 心理健康方面，倒班工作已被归类为2A型“可能致癌物质”。最近的研究表明， 环境或遗传对昼夜节律的破坏可促进小鼠肺癌的发生 这种疾病的模型。我们试图进行类似的研究，以评估昼夜节律中断是否会影响 胰腺癌的发展和/或进展。据估计，胰腺癌将夺走 2021年，美国有近48,000人死于癌症，使其成为美国与癌症相关的第三大死亡原因。 这种疾病的预后非常糟糕，中位生存期约为8个月。这一可怕的预测 反映了诊断时的晚期疾病和胰腺癌对目前的耐药性 采用治疗方案，强调需要更深入地了解分子基础 这种疾病的危害。这样的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，了解昼夜节律的干扰是否会增强 胰腺肿瘤的发生和/或发展，并对参与这一过程的因素进行表征是非常重要的 意义。因此，这一提议将直接检验这样一个假设，即昼夜节律扰乱增强了 胰腺癌的发生和发展。 在第一个特定的目标中，我们将测试这样一个假设，即由改变的照明方案引起的昼夜节律中断 促进称为胰腺上皮内肿瘤的胰腺癌前病变的发展 (Panins)在经过验证的FSF-KrasG12D；Pdx1-flp(KF)小鼠模型中。我们将进一步评估昼夜节律 在这个模型中，破坏促进了向浸润性癌的进展，在FSF中也是如此 KrasG12D；Trp53FRT/+；Pdx1-flp(KPF)模型。以机械的方式洞察昼夜节律的混乱是如何促进 对于胰腺肿瘤的发生，我们还将对荷瘤小鼠进行代谢评估。我们会 还要对一组肿瘤进行单细胞RNA测序，以确定 特别是与昼夜节律紊乱后诱发的肿瘤有关。 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。我们将产生复合遗传小鼠品系， 促进肿瘤的Kras和Trp53等位基因与神经元特异性的BMal1缺失相结合 会打乱正常的昼夜节律。代谢和基因表达变化的平行评估 在这些小鼠中，当与来自AIM 1的数据相结合时，将允许对基因和途径进行强有力的识别 为将来的研究排定优先顺序。 总的来说，拟议的研究将阐明昼夜节律紊乱对胰腺的潜在贡献。 癌症的发展和进展。他们还将为未来的研究奠定基础，这些研究将审问 潜在的深入机制，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.