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

• 批准号: 8003742
• 负责人: Stephanie Olga Peacock
• 金额: $ 4.64万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 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/8003742
• 关键词: Age; American; Androgen Receptor; Androgens; Antineoplastic Agents; Bone Pain; Cancer Diagnostics; Cancer Etiology; Castration; Cell Nucleus; Cells; Cessation of life; Chemicals; Chemosensitization; Data; Diagnostic Neoplasm Staging; Gene Cluster; Gene Expression; Gene Targeting; Guanine Nucleotide Exchange Factors; Hand; Human; Immunocompromised Host; In Vitro; Indium; Knockout Mice; LNCaP; Ligands; Malignant Neoplasms; Malignant neoplasm of prostate; Modeling; Molecular; Molecular Profiling; Mus; Mutant Strains Mice; Mutation; Neoplasm Metastasis; 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; 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; prognostic; public health relevance; rho GTP-Binding Proteins; tumor; urinary

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. PUBLIC HEALTH RELEVANCE: 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. Androgen receptor (AR) and its co-activating proteins play a key role in increasing prostate cancer's malignancy, metastatic potential and debilitating physical symptoms. This research endeavors to delineate the pathways behind the ability of an AR activating protein (Vav3) to increase the malignancy of prostate cancer with the eventual aim of providing a new target for a prostate cancer drug and a prostate cancer diagnostic marker.

描述（由申请人提供）：前列腺癌是美国最常见的非皮肤恶性肿瘤，是美国男性癌症相关死亡的第二大原因，并且是与年龄关系最密切的人类恶性肿瘤之一。晚期前列腺癌最常见的治疗方法之一是通过化学或物理去势来剥夺雄激素。不幸的是，大多数患者会复发并继续经历令人衰弱的骨痛、泌尿系统症状和性功能障碍。在此阶段，癌症被称为雄激素非依赖型或去势抵抗型（CRPC）；然而，研究表明，这一阶段的癌症仍然依赖于雄激素受体 (AR) 信号传导。参与这种增强的 AR 转录活性的蛋白质之一是 Vav3，一种 Rho GTPase 鸟嘌呤核苷酸交换因子。在雄激素非依赖性人类前列腺癌和年龄相关前列腺癌的 Nkx3.1;Pten 突变小鼠模型中，Vav 3 在体外和体内均上调。 Vav3 在生理和亚纳摩尔雄激素浓度下均增强 AR 活性，类似于 CRPC 中证明的前列腺微环境水平。因此，Vav3 水平升高似乎对于雄激素非依赖性癌症中持续的 AR 信号传导至关重要。在雄激素存在的情况下，Vav3 AR 转录活性的增强需要 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 被排除在细胞核之外，并且无法招募到 AR 靶基因中的雄激素反应元件。另一方面，组成型活性 Vav3 已被证明可以通过 GEF 活性和 Rho GTPase Rac1 增强配体独立的 AR 激活。通过利用功能分离 Vav3 突变体的方法，可以确定配体独立的 Vav3 GEF 活性和配体依赖性的 Vav3 AR 共激活的贡献。在这项研究中，各种Vav3突变体将被稳定转染到Vav3缺陷型前列腺癌细胞系LNCaP中，并检查它们的基因表达谱，以确定Vav3增强AR转录活性的分子途径。然后将 Vav3 功能分离突变体原位注射到免疫功能低下小鼠的前列腺中，以更好地重建前列腺微环境。将评估这些细胞的体外和体内侵袭和细胞生长的差异，以检查不同的 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，Nkx3.1;Pten 突变小鼠是衰老依赖性前列腺癌的忠实模型，将在与可用的 Vav3 缺失小鼠交配后进行检查，以确定 Vav3 信号在该模型中的贡献。将确定的在各种形式的 Vav3 稳定转染的前列腺癌细胞中上调或下调的前哨基因表达途径与 Nkx3.1;Pten 和 Nkx;Pten;Vav3 敲除小鼠模型中产生的表达模式进行比较。此外，通过将通过基因图谱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果进行比较，可以鉴定新的Vav3信号通路，从而发现新的诊断标记物。 公共健康相关性：前列腺癌是美国最常见的非皮肤恶性肿瘤，是美国男性癌症相关死亡的第二大原因，也是与年龄关系最密切的人类恶性肿瘤之一。雄激素受体 (AR) 及其共激活蛋白在增加前列腺癌的恶性程度、转移潜力和使人衰弱的身体症状方面发挥着关键作用。本研究致力于阐明 AR 激活蛋白 (Vav3) 增加前列腺癌恶性程度背后的途径，最终目的是为前列腺癌药物和前列腺癌诊断标记物提供新靶点。