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：
8761385
负责人：
MARK Reid PHILIPS
金额：
$ 21.1万
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：
2013
资助国家：
美国
起止时间：
2013-12-10 至 2014-09-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8761385
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 Targeting 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.

描述（由申请人提供）：Ras 基因在癌症中比任何其他癌基因更频繁地发生突变。 Ras 蛋白通过一系列翻译后修饰（包括法呢基化、蛋白水解和羧基甲基化）与膜结合。 Ras 蛋白仅在与细胞膜结合时才具有生物活性。因此，Ras加工途径长期以来一直被认为是抗癌药物的一个有吸引力的靶点。我们克隆并表征了异戊二烯半胱氨酸羧基甲基转移酶 (Icmt)，它是修饰 Ras 和其他 CAAX 蛋白的三种酶中的第三种。为了验证 Icmt 作为抗癌药物靶点，我们研究了由条件致癌 K-Ras 等位基因 (LSL-KrasG13D) 驱动的胰腺导管腺癌 (PDA) 小鼠模型。 Icmt 在表达致癌 K-Ras 的相同胰腺细胞中被消除（基因型 Pdx-1-Cre；Icmtfl/fl；KrasLSL/+）。我们非常惊讶地发现 Icmt 缺乏显着加剧 K-Ras 驱动的胰腺上皮内瘤变 (PanIN)。这一惊人的结果不仅表明 Icmt 可能不适合药物靶向，而且还表明该酶及其一种或多种底物在某些情况下可充当肿瘤抑制因子。我们建议在三个具体目标中阐明 Icmt 的肿瘤抑制样活性：目标 1：表征 Icmt 缺陷在 LSL-KrasG12D 驱动的 PanIN 病变恶化中的特征。我们将对 Pdx-1-Cre;Icmtfl+l;KrasLSL/+ 与 Pdx-1-Cre;Icmtfl/fl;KrasLSL/+ 动物中观察到的 PanIN 损伤进行免疫组织化学表征，我们将确定 Icmt 缺陷是否对 Pdx 产生影响-1-Cre;KrasLSL/+ PanIN 发育模型需要消融导管上皮中的 Icmt，我们将确定是否加剧的 PanIN 代表胰腺导管上皮细胞 (PDEC) 的细胞自主效应，我们将确定 Icmt 缺陷对雨蛙素诱导的胰腺炎症的影响。目标 2：Icmt 缺陷对另一种小鼠肿瘤模型的影响。我们将确定 Icmt 在 K-Ras 驱动的癌症替代模型以及依赖于致癌 H-Ras 的模型中是否表现得像肿瘤抑制因子。目标 3：培养细胞中 Icmt 缺陷的分子标记。我们将研究分离的原代 PDEC，以发现 Icmt 缺陷的分子标记，并确定哪种底物或哪些底物负责 Icmt 消融的生长促进作用。由于 Notch1 缺陷表现出 Pdx-1-Cre;KrasLSL/+ 模型中 Icmt 缺陷的表型，因此我们还将研究 Notch 信号传导中对 Icmt 的需求。我们相信，了解 Icmt 发挥肿瘤抑制作用的机制不仅将为 Ras 途径中的药物发现提供信息，还将揭示癌症生物学的新的重要方面。