Modeling androgen receptor in prostate cells

前列腺细胞中雄激素受体的建模

• 批准号: 7673645
• 负责人: Hsing-Jien Kung
• 金额: $ 30.54万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7673645
• 关键词: Ablation; Acetylation; Alleles; Androgen Receptor; Androgens; Area; Biological; Calpain; Cell Line; Cells; Cleaved cell; Complete Androgen-Insensitivity Syndrome; Complex; DNA Binding Domain; Data; Development; Differentiation and Growth; EGF gene; Epigenetic Process; Evolution; Exons; Funding; Gastrin releasing peptide; Gene Mutation; Generations; Genes; Genetic; Grant; Growth; Growth Factor; Hormones; Interleukin-6; Knowledge; Laboratories; Length; Ligand Binding Domain; Ligands; Malignant Neoplasms; Malignant neoplasm of prostate; Methodology; Modeling; Modification; Molecular; Molecular Profiling; Mutation; N-terminal; National Institute of Diabetes and Digestive and Kidney Diseases; Neuropeptides; One-Step dentin bonding system; Pathway interactions; Peptide Hydrolases; Phosphorylation; Post-Translational Protein Processing; Process; Property; Prostate; Prostatic Diseases; Protein Tyrosine Kinase; Protein-Serine-Threonine Kinases; Publications; Reagent; Receptor Activation; Refractory; Relapse; Request for Applications; Research; Research Personnel; Role; Signal Transduction; Steroids; Structure-Activity Relationship; Testing; Tissues; Transactivation; Xenograft procedure; base; casein kinase; cytokine; effective therapy; fascinate; hormone refractory prostate cancer; innovation; insight; mutant; novel; overexpression; programs; receptor; src-Family Kinases; tumor

DESCRIPTION (provided by applicant): Androgen receptor is a critical molecule involved in the normal development of prostate tissues and in the growth and progression of prostate cancer. Mutations of androgen receptor are associated with androgen insensitivity and testicular feminization syndrome as well as prostate cancer. Characterization of these mutations have contributed greatly to our knowledge about the structure-function relationship of androgen receptor, as well as their roles of in development, differentiation and growth of prostate cells. Androgen receptor is a ligand induced transcriptional factor which in combination with co-regulators induce differentiation and growth genes in different cellular context. Androgen receptor activity is modulated not only by its natural ligand, androgen, but also by growth factors and cytokines such as IL-6, EGF and gastrin-releasing peptide. These non-steroid ligands activate tyrosine kinases (e.g., EGF-R and Src) and serine kinases (e.g., MARK and casein kinase), resulting in the post translational modification of androgen receptor including phosphorylation, sumoylation, acetylation and cleavage by proteases. The most troubling aspect of prostate cancer is its conversion to androgen independence, which defies any effective treatment including androgen-ablation. Accumulating evidence suggests that inappropriate activation of androgen receptor by non-steroids and genetic mutation of androgen receptor may represent two major complementary mechanisms responsible for the evolution of androgen independence of prostate cancers. Our lab has been studying both mechanisms and discovered a novel mutation of androgen receptor in CWR22 xenograft, during its evolution to androgen independence. CWR22 xenograft has been used by many laboratories world-wide and become one of the favorite models to study androgen independence conversion. Using a novel allele-replacement approach, we wish to demonstrate that the mutation which duplicates exon 3 of androgen receptor locus is the genetic basis of hormone refractory transformation of this xenograft cell line and uncover a novel new mechanism of androgen independence. This mutation sensitizes androgen receptor toward cleavage by cellular protease calpain and generates a constitutively active receptor carrying only the N-terminal domain. Overexpression of calpain and the cleaved N-terminal domain product are often found in prostate cancer tissues. Signals that modulate calpain activity such as Src tyrosine kinase may contribute to such cleavage in an epigenetic manner. Our proposal will contribute to 1) a detailed understanding of an androgen receptor mutation which underlies androgen independence in CWR22.2) the molecular pathway which contributes to the generation of truncated androgen receptor and 3) the development of an effective allele replacement strategy to study the tumor-associated androgen receptor mutation. The result will provide insights into the genetic and epigenetic mechanisms of androgen independence, which goes beyond the study of CWR22.

描述（申请人提供）：雄激素受体是参与前列腺组织正常发育以及前列腺癌生长和进展的关键分子。雄激素受体突变与雄激素不敏感、睾丸女性化综合征以及前列腺癌有关。这些突变的表征极大地促进了我们对雄激素受体的结构-功能关系及其在前列腺细胞发育、分化和生长中的作用的认识。雄激素受体是一种配体诱导的转录因子，与共调节剂结合可诱导不同细胞环境中的分化和生长基因。雄激素受体活性不仅受到其天然配体雄激素的调节，还受到生长因子和细胞因子（例如 IL-6、EGF 和胃泌素释放肽）的调节。这些非类固醇配体激活酪氨酸激酶（例如，EGF-R和Src）和丝氨酸激酶（例如，MARK和酪蛋白激酶），导致雄激素受体的翻译后修饰，包括磷酸化、苏酰化、乙酰化和蛋白酶切割。前列腺癌最令人不安的方面是它转变为雄激素独立性，这无法接受任何有效的治疗，包括雄激素消除。越来越多的证据表明，非类固醇对雄激素受体的不适当激活和雄激素受体的基因突变可能代表了导致前列腺癌雄激素非依赖性进化的两个主要互补机制。我们的实验室一直在研究这两种机制，并在 CWR22 异种移植物进化到雄激素独立的过程中发现了雄激素受体的一种新突变。 CWR22异种移植物已被全球许多实验室使用，并成为研究雄激素非依赖性转化最喜爱的模型之一。使用一种新的等位基因替换方法，我们希望证明雄激素受体基因座外显子3重复的突变是该异种移植细胞系激素难治性转化的遗传基础，并揭示雄激素非依赖性的新机制。这种突变使雄激素受体对细胞蛋白酶钙蛋白酶的裂解敏感，并产生仅携带 N 末端结构域的组成型活性受体。钙蛋白酶和切割的 N 末端结构域产物的过度表达经常在前列腺癌组织中发现。调节钙蛋白酶活性的信号（例如 Src 酪氨酸激酶）可能以表观遗传方式促进这种切割。我们的建议将有助于 1) 详细了解 CWR22 中雄激素独立性基础的雄激素受体突变。2) 有助于生成截短雄激素受体的分子途径，以及 3) 开发有效的等位基因替换策略来研究肿瘤相关雄激素受体突变。该结果将为雄激素独立性的遗传和表观遗传机制提供见解，这超出了 CWR22 的研究范围。