Genome-Wide Analysis of Transcription Factor Function in Prostate Cancer

描述(申请人提供)：雄激素受体(AR)，一种配体依赖的转录因子，在前列腺癌的发生和发展中发挥关键作用，是治疗的靶点。令人惊讶的是，人们对AR结合、AR协同转录因子以及对人类基因组中AR靶基因的调控知之甚少。这一建议的总体目标是从基因组的角度提高我们对雄激素依赖(AD)和非依赖性(Al)前列腺癌细胞中AR、其协同转录因子及其共激活因子对靶基因的组合转录调控的理解。为了解决这些问题，我们将使用染色质免疫沉淀(ChIP)结合人类全基因组询问拼接微阵列(ChlP-on-Chip)来研究转录因子在AD和Al前列腺癌中的体内结合及其调控功能。我们的具体目标是：(1)确定AD和A1前列腺癌细胞中是否存在不同的AR结合、AR协同转录因子伙伴和AR靶基因。AR ChlP-on-Chip分析将在AD和A1前列腺癌细胞中进行。AR结合、协同转录因子和AR靶基因将通过生物信息学算法进行预测和实验验证。(2)研究AR及其协同转录因子对AD和A1前列腺癌细胞中AR靶基因的联合调控作用。协同转录因子ChlP-on-Chip将与AR ChlP-on-Chip和基因表达谱相关联，以确定AD和A1前列腺癌细胞中AR靶基因的组合转录调控密码和机制。来自前列腺癌细胞系的组合调控结果将与来自临床样本的微阵列数据相关联，以验证临床相关性。(3)确定共激活子在从Aim 1和Aim 2中筛选出的新的AR靶基因中如何发挥协同调节作用。将研究共激活子、AR和协同因子之间的物理相互作用。共激活子在AR和协同因子结合、靶基因表达和前列腺癌细胞生长和存活中的功能作用将被确定。这些研究将确定在AD和Al前列腺癌中AR、协同转录因子和辅活化子对靶基因的差异转录调控的潜在机制，并将导致为治疗干预确定新的分子靶点。

DESCRIPTION (provided by applicant): The androgen receptor (AR), a ligand-dependent transcription factor, plays a key role in the onset and progression of prostate cancer and is a therapeutic target. Surprisingly little is known of AR binding, AR collaborating transcription factors, and regulation of AR target genes in the human genome. The overall goal of this proposal is to improve our understanding of the combinatorial transcriptional regulation of target genes by AR, its collaborating transcription factors and its coactivators from a genome-wide view in androgen-dependent (AD) and -independent (Al) prostate cancer cells. To address these issures, we will use chromatin immunoprecipitation (ChIP) combined with human whole genome interrogating tiling microarrays (ChlP-on-chip) to study in vivo binding of transcription factors and their regulatory function in AD and Al prostate cancer. Our specific aims are to: (1) Determine whether distinct AR binding, AR collaborating transcription factor partners and AR target genes exist in AD and Al prostate cancer cells. AR ChlP-on-chip assays will be performed in AD and Al prostate cancer cells. AR binding, its collaborating transcription factors and AR target genes will be predicted by bioinformatics algorithms and experimentally validated. (2) Determine how AR and its collaborating transcription factors combinatorially regulate AR target genes in AD and Al prostate cancer cells. Collaborating transcription factor ChlP-on-chip will be performed and correlated with AR ChlP-on-chip and gene expression profiles to identify combinatorial transcriptional regulatory codes and mechanisms for AR target genes in AD and Al prostate cancer cells. The combinatorial regulation results from prostate cancer cell lines will be correlated with mircroarray data from clinical samples to verify clinical relevance. (3) Determine how coactivators play coregulatory roles in selected novel AR target genes identified from aim 1 and aim 2. The physical interactions among coactivators, AR and collaborating factors will be studied. The functional roles of coactivators in AR and collaborating factors binding, target gene expression and prostate cancer cell growth and survival will be determined. These studies will define the mechanisms underlying the differential transcriptional regulation of target genes by AR, collaborating transcription factors and coactivators in AD and Al prostate cancer and will lead to the identification of new molecular targets for therapeutic intervention.