Genome-Wide Analysis of Transcription Factor Function in Prostate Cancer

描述（申请人提供）：雄激素受体（AR）是一种配体依赖性转录因子，在前列腺癌的发生和进展中起关键作用，是治疗靶点。令人惊讶的是，很少有人知道AR结合，AR协作转录因子，以及人类基因组中AR靶基因的调控。该提案的总体目标是提高我们对AR、其协作转录因子及其共激活因子在雄激素依赖性（AD）和非依赖性（Al）前列腺癌细胞中从全基因组角度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平铺微阵列（ChIP-on-chip）来研究AD和Al前列腺癌中转录因子的体内结合及其调控功能。我们的具体目标是：（1）确定AD和Al前列腺癌细胞中是否存在不同的AR结合、AR协作转录因子配偶体和AR靶基因。AR ChIP芯片测定将在AD和Al前列腺癌细胞中进行。AR结合，其协作转录因子和AR靶基因将通过生物信息学算法预测和实验验证。(2)确定AR及其协作转录因子如何组合调节AD和Al前列腺癌细胞中的AR靶基因。将进行协作转录因子ChIP芯片，并将其与AR ChIP芯片和基因表达谱相关联，以鉴定AD和Al前列腺癌细胞中AR靶基因的组合转录调控代码和机制。前列腺癌细胞系的组合调控结果将与临床样品的微阵列数据相关联，以验证临床相关性。(3)确定辅激活因子如何在目标1和目标2中确定的选定新AR靶基因中发挥协同调节作用。将研究共激活因子、AR和协同因子之间的物理相互作用。将确定辅助激活因子在AR和协作因子结合、靶基因表达和前列腺癌细胞生长和存活中的功能作用。这些研究将定义AR、协作转录因子和AD和Al前列腺癌中的共激活因子对靶基因的差异转录调节的潜在机制，并将导致识别用于治疗干预的新分子靶点。

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.