Study the Mechanism of Retinoblastoma Protein Mediated Androgen Receptor Transcriptional Repression Activity on DNA Replication

视网膜母细胞瘤蛋白介导的雄激素受体转录抑制活性对DNA复制的机制研究

基本信息

批准号：
10245265
负责人：
Changmeng Cai
金额：
$ 34.88万
依托单位：
UNIVERSITY OF MASSACHUSETTS BOSTON
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-25 至 2023-08-31
项目状态：
已结题

项目摘要

Project Summary While AR has been extensively characterized as a transcriptional activator, it was recently reported to function as a transcriptional repressor to suppress a subset of genes. Significantly, through AR ChIP-seq and transcriptome profiling in prostate cancer cells we have found that the directly AR-repressed genes are highly enriched for DNA replication function and majority of those genes were consistently increased in CRPC clinical samples. We then discovered that this direct transcriptional repression activity of AR was mediated by androgen-stimulated recruitment of hypophosphorylated Rb. Androgens is also known to stimulate growth by further AR transcriptional activation of genes driving lipid and sterol synthesis, and other metabolic functions, with subsequent cyclin dependent kinase activation and Rb hyperphosphorylation. Overexpression of AR in prostate cancer cells could overcome this growth stimulatory effect. These findings demonstrate that AR has an Rb-dependent anti-proliferative function, which may be compromised in CRPC cells with Rb-deficiency and could be enhanced by blocking Rb phosphorylation. The objective of this proposal is to determine the function roles of AR recruitment of Rb in regulating transcription of DNA replication genes and cell cycle progression of PCa tumor cells (specific aim 1), to determine the molecular basis for AR interaction with hypophosphorylated Rb and characterize the distinct Rb complex recruited by AR to the suppression sits (specific aim 2), and to conduct a genome wide analysis to identify Rb dependent AR suppression sites and determine the mechanism of actions and function roles of these sites in prostate cancer cells (specific aim 3).

项目摘要尽管AR已被广泛地表征为转录激活剂，但最近据报道作为转录阻遏物抑制基因子集的功能。值得注意的是，通过AR chip-seq和前列腺癌细胞中的转录组分析我们发现，直接被AR抑制的基因是高度的在CRPC临床中，富含DNA复制功能和大多数基因的大多数始终增加样品。然后，我们发现AR的这种直接转录抑制活性是由雄激素刺激的下磷酸化RB的募集。众所周知，雄激素可以通过进一步的AR转录激活驱动脂质和固醇合成的基因以及其他代谢功能，随后的细胞周期蛋白依赖性激酶激活和RB高磷酸化。 AR的过表达前列腺癌细胞可以克服这种生长刺激作用。这些发现表明AR有依赖RB的抗增殖功能，该功能可能在具有RB缺陷的CRPC细胞中受到损害可以通过阻断RB磷酸化来增强。该提案的目的是确定功能 AR募集RB在调节DNA复制基因转录和细胞周期进程中的作用 PCA肿瘤细胞（特定目标1），以确定与降压磷酸化的AR相互作用的分子基础 RB并表征AR招募到抑制作用的独特的RB复合物（特定的目标2），并进行基因组广泛的分析以识别依赖RB的AR抑制位点并确定机制这些位点在前列腺癌细胞中的作用和功能作用（特定目标3）。