Modeling androgen receptor in prostate cells

前列腺细胞中雄激素受体的建模

• 批准号: 7905189
• 负责人: Hsing-Jien Kung
• 金额: $ 30.23万
• 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 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7905189
• 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（由申请人提供）：雄激素受体是参与前列腺组织正常发育和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。对这些突变的研究有助于我们进一步了解雄激素受体的结构与功能的关系，以及它们在前列腺细胞发育、分化和生长中的作用。雄激素受体是一种配体诱导的转录因子，它与辅调节因子结合在不同的细胞环境中诱导分化和生长基因。雄激素受体活性不仅受其天然配体雄激素调节，还受生长因子和细胞因子如IL-6、EGF和胃泌素释放肽调节。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、类小泛素化、乙酰化和蛋白酶切割。前列腺癌最令人不安的方面是它向雄激素非依赖性的转化，这使得任何有效的治疗都无法奏效，包括雄激素消融。越来越多的证据表明，雄激素受体的不适当激活和雄激素受体的基因突变可能是两个主要的互补机制，负责前列腺癌的雄激素非依赖性的演变。我们的实验室一直在研究这两种机制，并在CWR 22异种移植物中发现了一种新的雄激素受体突变，在其向雄激素非依赖性的进化过程中。CWR 22异种移植瘤已被国内外许多实验室采用，成为研究雄激素非依赖性转换的最受欢迎的模型之一。利用一种新的等位基因替代方法，我们希望证明，重复雄激素受体基因座外显子3的突变是这种异种移植细胞系激素难治性转化的遗传基础，并揭示一种新的雄激素非依赖性的新机制。该突变使雄激素受体对细胞蛋白酶钙蛋白酶裂解敏感，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，如Src酪氨酸激酶，可能有助于以表观遗传方式进行这种切割。我们的建议将有助于1）详细了解CWR 22中雄激素非依赖性的雄激素受体突变。2）有助于产生截短雄激素受体的分子途径和3）开发有效的等位基因替代策略来研究肿瘤相关的雄激素受体突变。这一结果将为雄激素非依赖性的遗传和表观遗传机制提供新的见解，这超出了对CWR 22的研究。