Characterization of lcmt in Animal Models of Cancer

癌症动物模型中 lcmt 的表征

基本信息

批准号：
8370719
负责人：
MARK Reid PHILIPS
金额：
$ 35.15万
依托单位：
NEW YORK UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-07-16 至 2017-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8370719
关键词：
Ablation Active Sites Adult Alleles Amylases Animal Cancer Model Animals Antineoplastic Agents Biology Bypass C-terminal CDKN2A gene Caerulein Cancer Biology Cancer Model Cells Cellular Membrane Characteristics Cultured Cells Cutaneous Cyclin D1 Cysteine Development Drug Delivery Systems Ductal Ductal Epithelial Cell Ductal Epithelium Elastases Employee Strikes Endocrine Endoplasmic Reticulum Enzymes Gene Expression Profile Genes Genotype Growth Human Inflammation Insulin Keratin-19 Knockout Mice Lesion Malignant Neoplasms Malignant neoplasm of lung Malignant neoplasm of pancreas Maps Matrilysin Mediating Membrane Methylation Methyltransferase Modeling Modification Molecular Mucins Mus Mutate NF-kappa B Neoplasms Oncogene Activation Oncogenes Oncogenic Pancreas Pancreatic Ductal Adenocarcinoma Pancreatic Intraepithelial Neoplasia Pancreatitis Pathway interactions Pharmaceutical Preparations Phenocopy Post-Translational Protein Processing Process Proteins Proteolysis RAS genes Series Signal Pathway Signal Transduction Somatic Mutation Stromal Change Study models Sum Techniques Testing Therapeutic Intervention Tissues Tumor Suppressor Proteins Work cell type cytokine dimethylbenzanthracene drug discovery expectation farnesylation follow-up in vivo molecular marker mouse model notch protein pancreatic neoplasm protein-S-isoprenylcysteine O-methyltransferase ras Proteins research study senescence tumor tumor growth tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): Ras genes are mutated in cancer more frequently than any other oncogene. Ras proteins associate with membranes by virtue of a series of post-translational modifications that include farnesylation, proteolysis and carboxyl methylation. Ras proteins are biologically active only when associated with cellular membranes. Accordingly, the Ras processing pathway has long been considered an attractive target for anti-cancer drugs. We have cloned and characterized isoprenylcysteine carboxyl methyltransferase (Icmt), the third of the three enzymes that modifies Ras and other CAAX proteins. To validate Icmt as an anti-cancer drug target we studied a mouse model of pancreatic ductal adenocarcinoma (PDA) driven by a conditional oncogenic K-Ras allele (LSL-KrasG13D). Icmt was ablated in the same pancreatic cells in which oncogenic K-Ras was expressed (genotype Pdx-1-Cre;Icmtfl/fl;KrasLSL/+). We were extremely surprised to observe that Icmt deficiency markedly exacerbated K-Ras driven pancreatic intraepithelial neoplasia (PanIN). This striking result not only suggests that Icmt may not be suitable for drug targeting but it also suggests that the enzyme, and by inference one or more of its substrates, acts as a tumor suppressor in some contexts. We propose to elucidate the tumor suppressor-like activity of Icmt in three specific aims: Aim 1: Characterization of Icmt deficiency in the exacerbation of LSL-KrasG12D driven PanIN lesions. We will characterize immunohistochemically the PanIN lesions observed in Pdx-1- Cre;Icmtfl+l;KrasLSL/+ vs Pdx-1-Cre;Icmtfl/fl;KrasLSL/+ animals, we will determine if the effect of Icmt deficiency on the Pdx-1-Cre;KrasLSL/+ model of PanIN development requires ablation of Icmt in ductal epithelium, we will determine if the exacerbated PanINs represent a cell autonomous effect of pancreatic ductal epithelial cells (PDECs), and we will determine the effect of Icmt deficiency on caerulein-induced pancreatic inflammation. Aim 2: Effect of Icmt deficiency on alternate mouse models of neoplasia. We will determine if Icmt behaves like a tumor suppressor in an alternate model of K-Ras driven cancer as well as a model that depends on oncogenic H-Ras. Aim 3: Molecular markers of Icmt deficiency in cultured cells. We will study isolated primary PDECs to discover molecular markers of Icmt deficiency and to determine which substrate, or substrates, is responsible for the growth promoting effect of Icmt ablation. Because Notch1 deficiency phenocopies Icmt deficiency in the Pdx-1-Cre;KrasLSL/+ model we will also study the requirement for Icmt in Notch signaling. We believe that understanding the mechanism through which Icmt behaves like a tumor suppressor will not only inform drug discovery in the Ras pathway but will reveal new and important aspects of cancer biology. PUBLIC HEALTH RELEVANCE: Ras is the most important gene associated with human cancer. We have studied the mechanisms whereby Ras proteins become associated with cellular membranes in the hope of interfering with this process in order to develop anticancer drugs. In the current application we will investigate the effect on pancreatic cancer in mice of eliminating one of the genes that normally allows Ras to associate with membranes with higher efficiency.

描述（由申请人提供）：RAS基因在癌症中的突变比任何其他癌基因更频繁。 RAS蛋白质与膜相关，这是一系列翻译后修饰，包括法尼化，蛋白水解和羧基甲基化。 RAS蛋白仅在与细胞膜相关时才具有生物活性。因此，长期以来，RAS加工途径一直被认为是抗癌药物的吸引力。我们已经克隆并表征了异位甲基半胱氨酸羧基转移酶（ICMT），这是修饰RAS和其他CAAX蛋白的三种酶中的第三种。为了验证ICMT作为抗癌药物靶标，我们研究了由条件性致癌性K-Ras等位基因（LSL-KRASG13D）驱动的胰腺导管腺癌（PDA）的小鼠模型。 ICMT在表达致癌的K-RAS的相同胰腺细胞中烧蚀（基因型PDX-1-CRE； ICMTFL/FL; KRASLSL/+）。我们非常惊讶地发现，ICMT缺乏症显着加剧了K-RAS驱动的胰腺内肿瘤（Panin）。这种惊人的结果不仅表明ICMT可能不适合药物靶向，而且还表明该酶以及通过推断其底物在某些情况下可以作为肿瘤抑制剂。我们建议阐明ICMT在三个特定目的中的肿瘤抑制活性：目标1：ICMT缺乏症的表征在加剧LSL-KRASG12D驱动的Panin病变中。我们将在PDX-1- CRE中观察到的PANIN病变来表征; icmtfl+ l; kraslsl/+ vs pdx-1-cre; icmtfl/fl; kraslsl/+动物，我们将确定ICMT缺乏对PDX-1-CRE; krassl/+ krassl/pan in+模型的影响是否涉及pan in of pan in of pan in of pan in of pan in of pan in of pan in of pan in of pan in of pan in of pan/+ krassl/+ s。我们将确定加重的PANIN是否代表了胰管上皮细胞（PDEC）的细胞自主作用，我们将确定ICMT缺乏对Caerulein诱导的胰腺炎症的影响。 AIM 2：ICMT缺乏对肿瘤替代小鼠模型的影响。我们将确定ICMT在K-RAS驱动的癌症的替代模型中以及取决于致癌H-RAS的模型中的行为是否像肿瘤抑制剂。目标3：培养细胞中ICMT缺乏的分子标记。我们将研究孤立的主要PDEC，以发现ICMT缺乏症的分子标记，并确定哪些底物或底物是造成ICMT消融的生长促进作用的原因。由于Notch1缺乏型表型ICMT缺乏PDX-1-CRE; KRASLSL/+模型，因此我们还将研究Notch信号中ICMT的需求。我们认为，了解ICMT像肿瘤抑制剂一样的机制不仅会在RAS途径中发现药物发现，而且会揭示癌症生物学的新和重要方面。公共卫生相关性：RAS是与人类癌症相关的最重要基因。我们研究了RAS蛋白与细胞膜相关的机制，以期干扰此过程以开发抗癌药物。在当前的应用中，我们将研究消除通常允许RAS与较高效率与膜相关的基因的小鼠中对胰腺癌的影响。