Epigenomic Regulation in Pancreatic Cell Growth

这项提案要求更新我们长期用于研究抄写的主要资金来源， 染色质和表观遗传学在胰腺疾病的病理生理机制中的作用。我们的研究将 直接扩展我们对常见疾病的认识，如慢性胰腺炎和胰管 胰腺外分泌腺癌(PDAC)，是一种既痛苦又不可治愈的胰腺外分泌疾病，对哪种疾病有效 预防方案和治疗方法仍有待充分制定。我们的总体目标是 研究表观基因组调节因子如何作为人类常见突变的核效应因子发挥作用 胰腺疾病。尽管我们相信我们的概念和方法可以应用于任何 “突变-表观遗传-疾病三联体”，我们将重点了解基于组蛋白的通路作为 KRAS在已建立的基因工程小鼠和人类患者衍生的胰腺疾病模型中。 值得注意的是，虽然表观遗传变化类似于遗传变化，但它们可以通过以下方式逆转 药物治疗。我们的初步数据报告发现了组蛋白H3的关键作用 赖氨酸9(H3K9)甲基化途径及其相关甲基转移酶EHMT2作为表观遗传调节因子 致癌的KRAS。EHMT2及其同源基因EHMT1是主要的组蛋白赖氨酸甲基转移酶 负责催化组蛋白H3K9的二甲基化。然而，目前还不知道关于 EHMT1和EHMT2单独或作为一个复合体的功能，与胰腺生理或 胰腺疾病。我们将检验一个组合的、机械论的和平移论的中心假说，即 EHMT1/EHMT2复合体在ADM和Panin形成过程中作为KRAS的表观遗传效应 以及它们由胰腺炎引起的进展。我们的具体目标是：1.确定通过什么机制 EHMT1/2复合体失活拮抗KrasG12D介导的ADM和Panin的形成 胰腺炎；2.评估胰腺细胞内KRAS信号调节的生化机制 EHMT1/2复合体的酶活性；以及3.发现表观遗传机制 EHMT1/2复合体介导KRAS的作用。我们将使用大量的细胞、分子和 整个生物体实验，在高度协作的环境中进行，采用最先进的技术。 通过专注于更好地理解作为共同基因下游效应器的表观基因组途径 胰腺中的突变，我们的设计寻求最大限度地提高可快速翻译的机械产量 知识。这项提案的发现将产生有价值的积极影响，因为 表观基因组学领域的概念、技术和药物有望为 对受胰腺疾病影响的患者的管理，从而具有重大的生物医学意义。

This proposal requests the renewal of our major source of long-standing funding for investigating transcription, chromatin, and epigenetics in pathophysiological mechanisms underlying pancreatic diseases. Our studies will directly extend our knowledge on common diseases, such as chronic pancreatitis and pancreatic ductal adenocarcinoma (PDAC), both painful and incurable disorders of the exocrine pancreas for which effective prevention protocols and treatments remain to be fully developed. Our OVERALL OBJECTIVE is to investigate how epigenomic regulators work as nuclear effectors of common mutations associated with human pancreatic diseases. Although we believe that our concepts and methodologies can be applied to any “mutation-epigenetic-disease triad”, we will focus on understanding histone-based pathways as effectors of KRAS in established genetically-engineered mouse and human patient-derived models of pancreatic diseases. Notably, while similar to genetic alterations epigenetic changes are inheritable, they can be reversible by pharmacological treatment. Our PRELIMINARY DATA report the discovery of a key role for the Histone H3 Lysine 9 (H3K9) methylation pathway and its associated methyltransferase, EHMT2, as an epigenetic regulator of oncogenic KRAS. EHMT2 together with its paralog EHMT1 are the main histone lysine methyltransferases responsible for catalyzing histone H3K9 dimethylation. However, no information is known regarding the function of EHMT1 and EHMT2, either separately or as a complex, in relationship to pancreas physiology or pancreatic diseases. We will test a combined, mechanistic and translational CENTRAL HYPOTHESIS, namely that the EHMT1/EHMT2 complex works as an epigenetic effector of KRAS during ADM and PanIN formation as well as their progression by pancreatitis. Our SPECIFIC AIMS are: 1. To determine mechanisms by which inactivation of the EHMT1/2 complex antagonizes KRASG12D-mediated ADM and PanIN formation alone and in pancreatitis; 2. To evaluate biochemical mechanisms by which KRAS signaling in pancreatic cells regulates the enzymatic activity of the EHMT1/2 complex; and 3. To discover epigenetic mechanisms by which the EHMT1/2 complex mediates the effects of KRAS. We will use an extensive battery of cellular, molecular and whole organism experiments, executed in a highly collaborative environment with state-of-the-art techniques. By focusing on better understanding epigenomic pathways that serve as effectors downstream of common mutations in the pancreas, our design seeks to maximize the yield of rapidly translatable mechanistic knowledge. Discoveries from this proposal will have a valuable positive impact because the application of concepts, techniques, and drugs from the field of epigenomics is anticipated to provide new opportunities for the management of patients affected by pancreatic diseases, thereby bearing significant biomedical relevance.