Control of Prostate-Specific Gene Expression

描述（由申请人提供）：了解控制前列腺特异性基因表达的机制已经导致FoxA 1被鉴定为AR作用以及前列腺发育的重要共调节因子。我们现在已经证明USF 2与FoxA 1在多个前列腺特异性启动子上相互作用。这表明USF 2的功能是促进与分化相关的基因的表达，这与先前报道的USF 2通过下调c-myc抑制增殖的机制一致。用AR（信号依赖性）、FOXA 1（内胚层特异性发育细胞）和USF 2（分化特异性）的复合物控制前列腺特异性基因表达揭示了调节因子的显著结合以决定前列腺特异性基因表达。使用标记的FOXA 1进行亲和纯化，然后进行液相色谱/串联质谱（LC-MS/MS）的持续工作已经鉴定了16种核蛋白，其在两个单独的实验中满足每个蛋白至少两个肽命中的要求。其中，7种核蛋白可以直接或间接与AR/FOXA 1作用相关。确定控制前列腺特异性基因表达的因素对了解前列腺发育过程中的细胞命运、前列腺疾病的雄激素调节以及了解控制细胞决定和细胞分化的基本级联反应具有重要意义。基于已发表的和我们的初步数据，我们的假设是，通过鉴定控制前列腺特异性基因表达的TF，我们也鉴定了在前列腺发育中起关键作用的TF。提出了三个具体目标：目标1：表征AR调节的前列腺特异性基因的转录因子复合物;目标2：通过串联亲和纯化和液相色谱/串联质谱（LC-MS/MS）鉴定新的FOXA 1结合伴侣;目标3：确定已鉴定的TF在前列腺发育和雄激素依赖中的功能。确定控制前列腺特异性基因表达的剩余TF对于理解控制前列腺疾病如hBPH和PCa的雄激素调节的因素具有重要意义。公共卫生相关性：确定控制雄激素调节的前列腺特异性基因表达的因素对了解前列腺发育过程中的细胞命运、前列腺疾病的雄激素调节以及了解控制细胞决定和细胞分化的基本级联反应具有重要意义。

DESCRIPTION (provided by applicant): Understanding the mechanism that controls prostate-specific gene expression has already resulted in the identification of FoxA1 as an important co-regulator of AR action as well as prostate development. We have now demonstrated that USF2 interacts with FoxA1 on multiple prostate-specific promoters. This indicates that USF2 functions to promote expression of genes associated with differentiation consistent with previously reported mechanism whereby USF2 inhibits proliferation by down regulating c-myc. Controlling prostate- specific gene expression with a complex of AR (signal dependent), FOXA1 (developmental cell specific for endoderm) and USF2 (differentiation specific) reveals a remarkable coming together of regulatory factors to dictate prostate-specific gene expression. Continuing work using tagged FOXA1 for affinity purification followed with Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS) has identified 16 nuclear proteins that met the requirement of at least two peptide hits per protein in two separate experiments. Of these, 7 nuclear proteins can be either directly or indirectly linked to AR/FOXA1 action. Determining the factors that control prostate-specific gene expression has important implications for the understanding of cell fate during prostate development, androgen regulation of prostate disease, as well as understanding the fundamental cascade that controls cell determination and cell differentiation. Based upon published and our preliminary data, our Hypothesis is that by identifying the TFs that control prostate-specific gene expression, we are also identifying TF that play a critical role in prostate development. Three specific aims are proposed: Aim 1: To characterize the transcription factor complex of AR-regulated prostate-specific genes; Aim 2: To identify novel FOXA1 binding partners by tandem affinity purification followed with Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS); Aim 3: To determine the function of identified TFs in prostate development and androgen dependence. Determining the remaining TFs that control prostate-specific gene expression has important implications for the understanding the factors that control androgen regulation of prostatic diseases such as hBPH and PCa. PUBLIC HEALTH RELEVANCE: Determining the factors that control androgen regulated prostate-specific gene expression has important implications for the understanding of cell fate during prostate development, androgen regulation of prostate disease, as well as understanding the fundamental cascade that controls cell determination and cell differentiation.