Rb/E2F in Hormone signaling of Prostate Epithelium

前列腺上皮激素信号传导中的 Rb/E2F

• 批准号: 6881046
• 负责人: MARK L DAY
• 金额: $ 22.66万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6881046
• 关键词: androgen receptor; androgens; apoptosis; athymic mouse; biological signal transduction; cell growth regulation; cell line; cell proliferation; connective tissue cells; epithelium; gene deletion mutation; gene expression; genetic transcription; growth factor; hormone regulation /control mechanism; immunocytochemistry; laboratory rat; messenger RNA; paracrine; prostate; protein structure function; receptor expression; recombinant proteins; site directed mutagenesis; tissue /cell culture; tumor suppressor genes; tumor suppressor proteins

DESCRIPTION (provided by applicant): This laboratory has compiled extensive evidence supporting a novel role for the retinoblastoma gene product (pRb) and it's transcriptional regulatory partner, E2F1 in the regulation of androgen receptor expression and function. These findings have important implications for the regulation of prostate epithelial growth and survival. The lethal nature of the Rb knockout in mouse embryos has precluded gene disruption experiments to examine such a role for Rb in the prostate gland. To circumvent this problem and to initiate functional studies of Rb in the prostate gland, my laboratory has utilized an innovative approach to "rescue" Rb-/- prostate precursor rudiments from mouse embryos prior to their death with which we have generated the first viable Rb-/- prostate tissues and Rb-/-prostate epithelial cell lines. These models provide a unique experimental platform with which to investigate the physiologic consequences of Rb deletion on prostate epithelium. Using this technology, we have made the compelling observation that the loss of Rb results in non-transformed cells that exhibit increased expression of AR protein and mRNA, and in the presence of stromal growth factors, increased AR activity. We have also discovered that the specific loss of Rb results in immortalized prostate tissue and cells that are insensitive to apoptotic stimuli possibly due to an attenuated mitochondrial/caspase-9 pathway. Based on these findings, we hypothesize that Rb and AR are interacting components of a precisely regulated but poorly understood mechanism that controls the growth and survival of prostate epithelium. The proposed studies will determine the role of Rb/E2F 1 in the regulation of AR transcription and AR activity in cultured prostate epithelial cells and in recombinant prostate tissue in vivo. We will determine if Rb deletion results in increased AR responsiveness to paracrine growth factors secreted by prostate stromal cells and elucidate the specific signaling pathways that regulate AR function in this hormone-independent fashion. Lastly we will determine if the apoptotic mitochondrial/caspase-9 pathway is attenuated in the Rb-/- cells and tissue recombinants.

描述（由申请人提供）：该实验室已经编制了大量证据，这些证据支持视网膜母细胞瘤基因产物（PRB）及其转录调节伙伴E2F1在雄激素受体表达和功能调节中的新作用。这些发现对调节前列腺上皮生长和生存具有重要意义。小鼠胚胎中RB基因敲除的致命性具有排除基因破坏实验，以检查RB在前列腺中的作用。 To circumvent this problem and to initiate functional studies of Rb in the prostate gland, my laboratory has utilized an innovative approach to "rescue" Rb-/- prostate precursor rudiments from mouse embryos prior to their death with which we have generated the first viable Rb-/- prostate tissues and Rb-/-prostate epithelial cell lines.这些模型提供了一个独特的实验平台，可利用RB缺失在前列腺上皮上的生理后果。使用这项技术，我们已经提出了令人信服的观察，即RB的丧失导致未转化的细胞表现出增加AR蛋白和mRNA的表达增加，并且在存在基质生长因子的情况下增加了AR活​​性。我们还发现，RB的特异性损失导致可能是由于线粒体/caspase-9途径减弱的对凋亡刺激不敏感的细胞。基于这些发现，我们假设RB和AR正在相互作用的组成部分，这些组件是控制前列腺上皮的生长和存活的精确调节但知之甚少的机制。拟议的研究将确定RB/E2F 1在培养的前列腺上皮细胞和体内重组前列腺组织中AR转录和AR活性调节中的作用。我们将确定RB缺失是否会增加对前列腺基质细胞分泌的旁分泌生长因子的反应性，并阐明以这种激素独立的方式调节AR功能的特定信号通路。最后，我们将确定凋亡线粒体/caspase-9途径是否在RB - / - 细胞和组织重组中减弱。