Stopping the Start: Understanding PanIN Initiation and Progression

描述（由申请人提供）：目前的提案概述了一个研究培训计划，我将在约翰霍普金斯大学Steven Leach博士的指导下进行胰腺癌早期病变（PanIN）的发生和进展的复杂研究。超过80%的胰腺癌患者有Kras突变，胰腺癌的确切起源细胞尚未确定。因此，我们建议开发“下一代”小鼠PanIN形成模型，在该模型中，我们标记了与Kras融合的绿色荧光蛋白（GFP）细胞，以成像胰腺中经历重组并表达活化Kras的细胞。我们将在成年小鼠胰腺的腺泡室或导管室中激活Kras。通过GFP:Kras融合，我们将能够在致癌Kras表达激活后的离散时间点识别、可视化和分离细胞，从而实现一系列新颖的实验，在这些实验中，胰腺Kras激活的细胞反应甚至可以在PanIN病变形成之前进行研究，并且具有前所未有的空间和时间分辨率。使用这种新方法，我们将检验以下假设：首先，即使在形态PanIN形成开始之前，单个胰腺上皮细胞对致癌Kras表达的反应是基因表达、增殖和形态的进行性变化；其次，腺泡细胞和导管细胞在这些反应中可能表现出差异；第三，慢性胰腺炎影响对Kras的反应，最后，了解这些早期反应将允许从药理学上终止PanIN的起始和进展。

DESCRIPTION (provided by applicant): The current proposal outlines a research training program in which I will pursue sophisticated studies of the earliest lesions in pancreatic cancer (PanIN) initiation and progression under the mentorship of Dr. Steven Leach at Johns Hopkins University. Greater than 80% of pancreatic cancer patients have Kras mutations and the exact cell of origin for pancreatic cancer has not been defined. Therefore, we propose to develop a "next generation" mouse model of PanIN formation, in which we label cells with green flourescent protein (GFP) fused to Kras to image cells in the pancreas that have undergone recombination and express activated Kras. We will activate Kras in the acinar or ductal compartment of adult mouse pancreas. With the GFP:Kras fusion, we will be able to identify, visualize and isolate cells at discreet time points following activation of oncogenic Kras expression, empowering a series of novel experiments in which the cellular response to pancreatic Kras activation can be studied even prior to the formation of PanIN lesions, and with unprecedented spatial and temporal resolution. Using this novel approach, we will test the following hypotheses: First, that even prior to the onset of morphologic PanIN formation, individual pancreatic epithelial cells respond to oncogenic Kras expression with progressive changes in gene expression, proliferation, and morphology; second, that acinar and ductal cells may exhibit differences in these responses; third, that chronic pancreatitis influences the response to Kras, and finally, that understanding these earliest responses will allow the pharmacologic termination of PanIN initiation and progression. PUBLIC HEALTH RELEVANCE: Pancreatic cancer is an incredibly lethal form of cancer with a less than 5% chance of two year survival after diagnosis. We are proposing to study the earliest initiating events of pancreatic cancer to identify novel pathways for the treatment or diagnosis of this lethal disease. We believe these studies are relevant to better understand the earliest responses of ductal or acinar cells to oncogenic Kras activation.