Regulation of androgen receptor activity in prostate cancer cells in an aged mous

老年小鼠前列腺癌细胞雄激素受体活性的调节

基本信息

批准号：
8264189
负责人：
Stephanie Olga Peacock
金额：
$ 4.72万
依托单位：
UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-07-05 至 2016-07-04
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8264189
关键词：
Agar Age American Anchorage-Independent Growth Androgen Receptor Androgens Antineoplastic Agents Area Bone Pain Breeding Cancer Diagnostics Cancer Etiology Castration Cell Nucleus Cells Cessation of life Chemicals Chemosensitization Critical Pathways Data Diagnostic Neoplasm Staging Disease Drug Delivery Systems Gene Cluster Gene Expression Gene Expression Profile Gene Targeting Guanine Nucleotide Exchange Factors Human Immunocompromised Host In Vitro Indium Knock-out Knockout Mice LNCaP Ligands Malignant Neoplasms Malignant neoplasm of prostate Modeling Molecular Molecular Profiling Mouse Strains Mus Mutant Strains Mice Mutation Neoplasm Metastasis Nude Mice Outcome PC3 cell line PH Domain Partner in relationship Pathway interactions Patients Pattern Physiological Play Prostate Prostatic Prostatic Neoplasms Proteins Receptor Activation Receptor Signaling Regulation Relapse Relative (related person)Research Resistance Role Sentinel Sexual Dysfunction Signal Pathway Signal Transduction Symptoms United States age related aged cancer cell cell growth defined contribution deprivation experience genetic profiling in vivo male mouse model mutant mutant mouse model novel novel diagnostics outcome forecast prognostic rho GTP-Binding Proteins tumor tumor progression tumorigenic urinary

项目摘要

DESCRIPTION (provided by applicant): Prostate cancer is the most common non-dermatological malignancy in the United States, the second leading cause of cancer-related death in American males, and has one of the strongest relationships with age of any human malignancy. One of the most common therapies for advanced prostate cancer is androgen deprivation via chemical or physical castration. Unfortunately, most patients relapse and continue to experience debilitating bone pain, urinary symptoms, and sexual dysfunction. At this stage, the cancer is termed androgen-independent or castration resistant (CRPC); however, it has been shown that this stage of cancer remains dependent on androgen receptor (AR) signaling. One of the proteins implicated in this enhanced AR transcriptional activity is Vav3, a Rho GTPase guanine nucleotide exchange factor. Vav 3 is up-regulated both in vitro and in vivo in androgen-independent human prostate cancer and in the Nkx3.1;Pten mutant mouse model of age-related prostate cancer. Vav3 enhances AR activity at both physiological as well as at subnanomolar androgen concentrations, similar to prostatic microenvironment levels demonstrated in CRPC. Thus, elevated levels of Vav3 seem to be pivotal in the continued AR signaling in androgen-independent cancers. In the presence of androgen, Vav3 potentiation of AR transcriptional activity requires the Vav3 pleckstrin homology (PH) domain, but not guanine nucleotide exchange factor (GEF) activity. Furthermore, preliminary data suggests that a mutation in the PH domain causes Vav3 to be excluded from nuclei and incapable of recruitment to the androgen responsive element in an AR target gene. On the other hand, constitutively active Vav3 has been shown to enhance ligand-independent AR activation via GEF activity and the Rho GTPase Rac1. Through an approach utilizing separation-of-function Vav3 mutants, contributions of ligand-independent Vav3 GEF activity and ligand-dependent Vav3 coactivation of AR can be determined. In this study, various Vav3 mutants will be stably transfected into the Vav3 deficient prostate cancer cell line LNCaP and their gene expression profiles will be examined in order to identify the molecular pathways through which Vav3 enhances AR transcriptional activity. The Vav3 separation-of-function mutants will then be orthotopically injected into the prostates of immunocompromised mice in order to better recreate the prostatic microenvironment. These cells will be evaluated for differences of in vitro and in vivo invasion and cell growth in order to examine the role of distinct AR activation pathways in age-related prostate tumor formation and metastasis. In addition, Nkx3.1;Pten mutant mice, which are faithful models of aging-dependent prostate cancer, will be examined following mating with available Vav3 null mice to define the contribution of Vav3 signaling in this model. Identified sentinel gene expression pathways that are up or down-regulated in various forms of Vav3 stably transfected prostate cancer cells will be compared to the resulting expression patterns in both the Nkx3.1;Pten and Nkx;Pten;Vav3 knock out mouse models. Furthermore, by comparing the sentinel gene clusters identified via genetic profiling to the prognostic outcomes of the age-dependent tumors in the mutant mice, novel Vav3 signaling pathways may be identified and thus novel diagnostic markers uncovered.

描述（由申请人提供）：前列腺癌是美国最常见的非德学恶性肿瘤，这是美国男性与癌症相关死亡的第二大原因，并且与任何人类恶性肿瘤的年龄是最牢固的关系之一。晚期前列腺癌最常见的疗法之一是通过化学或物理cast割雄激素剥夺。不幸的是，大多数患者复发，并继续感到骨痛，尿症状和性功能障碍。在此阶段，癌症被称为抗雄激素独立或cast割抗性（CRPC）；但是，已经表明，癌症的这一阶段仍然取决于雄激素受体（AR）信号传导。与这种增强的AR转录活性有关的蛋白质之一是VAV3，一种Rho GTPase鸟嘌呤核苷酸交换因子。 VAV 3在雄激素独立的人前列腺癌和NKX3.1; PTEN突变小鼠与年龄相关的前列腺癌的模型中均在体外和体内上调。 VAV3在生理和亚纳摩尔雄激素浓度上都增强了AR活性，类似于CRPC中所示的前列腺微环境水平。因此，升高的VAV3水平似乎是雄激素非依赖性癌症的持续AR信号传导的关键。在存在雄激素的情况下，AR转录活性的VAV3增强需要Vav3 pleckstrin同源（pH）结构域，但不需要鸟嘌呤核苷酸交换因子（GEF）活性。此外，初步数据表明，pH结构域的突变导致VAV3从核中排除，并且无法募集到AR靶基因中的雄激素响应元件。另一方面，已显示组成性活性VAV3通过GEF活性和Rho GTPase Rac1增强了与配体无关的AR激活。通过利用功能分离的VAV3突变体的方法，可以确定非配体独立于VAV3 GEF活性的贡献和AR的配体依赖性VAV3共同激活。在这项研究中，将稳定转染各种VAV3突变体中的VAV3缺乏的前列腺癌细胞系LNCAP，并将检查其基因表达谱，以确定VAV3增强AR转录活性的分子途径。然后，VAV3分离突变体将原始注射到免疫功能低下的小鼠的前列腺中，以便更好地重现前列腺微环境。将评估这些细胞的体外和体内浸润和细胞生长的差异，以检查不同AR激活途径在与年龄相关的前列腺肿瘤形成和转移中的作用。此外，将在与可用的VAV3 null小鼠交配后检查NKX3.1; PTEN突变小鼠，它们是依赖衰老的前列腺癌的忠实模型，以定义该模型中VAV3信号的贡献。以各种形式的VAV3向上或下调的确定的哨基因表达途径稳定转染的前列腺癌细胞将与NKX3.1; PTEN和NKX; PTEN; VAV3; VAV3敲出小鼠模型的产生表达模式进行比较。此外，通过比较通过基因分析鉴定的前哨基因簇与突变小鼠中年龄依赖性肿瘤的预后结局，可以鉴定出新型的VAV3信号通路，从而发现了新颖的诊断标记。