Regulation of Stat Function in Breast Cancer

乳腺癌中 Stat 功能的调节

• 批准号: 7110975
• 负责人: Charles V Clevenger
• 金额: $ 25.34万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7110975
• 关键词: MCF7 cell; athymic mouse; binding proteins; breast neoplasms; chromatin; gene deletion mutation; gene expression; hormone receptor; immunoprecipitation; microarray technology; molecular oncology; peptidylprolyl isomerase; phosphorylation; point mutation; prolactin; protein localization; protein protein interaction; protein structure function; protooncogene; small interfering RNA; transcription factor

DESCRIPTION (provided by applicant): The Stat family of transcription factors is necessary for the growth and differentiation of mammary tissues. In mammary tissues, a significant means of Stat activation is the binding of the neuroendocrine hormone prolactin (PRL) to its receptor, the PRLr. PRL/PRLr binding results in the activation of receptor-associated signaling networks, such as the Jak/Stat pathway and the endocytosis and nuclear retrotransport of a complex between PRL and the prolyl isomerase cyclophilin B (CypB). The intranuclear PRL/CypB complex regulates Stat5-mediated gene expression and DNA binding. Using multiple approaches including yeast two-hybrid and transcription factor array analysis, we have demonstrated that the PRL/CypB complex regulates the interaction of Stat5 with multiple intranuclear proteins including the peptide inhibitor of activated Stat, PIAS3, the small ubiquitin-related modifier, SUMO2, and the transcription factor and proto-oncogene, c-Myb. It is the central hypothesis of this proposal that the temporal and spatial interaction of Stat5 with these proteins, as modulated by the PRL/CypB complex, regulates Stat5 function. This hypothesis will be tested by three specific aims using breast cancer and PRL-responsive cell lines both in vitro and in vivo. First, the structural basis for Stat5/PIAS3 interaction and the functional significance of this interaction will be mapped using complementary mutagenesis/overexpression and knockdown strategies. Second, the functional consequences of Stat5 sumolyation will be evaluated by cellular and biochemical approaches. Third, the association between Stat5 and co-activators/repressors, such as c-Myb will be assessed by targeted mutagenesis, small-interfering RNA (SiRNA), and chromatin immunoprecipitation (ChlP)-based methodologies. Given that our preliminary evidence indicates that the manipulation of these interactions results in the alteration of Stat5-mediated gene expression and the survival of breast cancer cells, our proposed studies are directly relevant to a better understanding of the pathophysiology of: human breast cancer, and as such, may provide the basis for novel therapeutic strategies aimed at modifying Stat function in this disease.

描述（由申请人提供）：转录因子的Stat系列对于乳腺组织的生长和分化是必需的。在乳腺组织中，统计激活的重要手段是神经内分泌激素催乳素（PRL）与其受体PRLR的结合。 PRL/PRLR结合导致受体相关信号网络的激活，例如JAK/STAT途径以及PRL与丙酰基异构酶环肽B（CYPB）之间复合物之间的复合物的内吞作用和核转传的激活（CYPB）。核内PRL/CYPB复合物调节STAT5介导的基因表达和DNA结合。使用多种方法包括酵母双杂交和转录因子阵列分析，我们证明了PRL/CYPB复合物调节STAT5与多种核内蛋白的相互作用，包括活化stat的肽抑制剂PIAS3，PIAS3，PIAS3，PIAS3，小型泛素蛋白相关的修饰剂SUMO2，SUMO2，转录因子和Proto-honceene，C-Moncen，C-Monceens，C-Myyb，C-Myyb。该提议的中心假设是，由PRL/CYPB复合物调节的STAT5与这些蛋白质的时间和空间相互作用调节STAT5功能。该假设将通过体外和体内的乳腺癌和PRL反应性细胞系进行三个特定目标测试。首先，使用补充诱变/过表达和敲低策略，将绘制STAT5/PIAS3相互作用的结构基础以及这种相互作用的功能意义。其次，STAT5共产力的功能后果将通过细胞和生化方法评估。第三，将通过靶向诱变，小型互换RNA（siRNA）和染色质免疫沉淀（CHLP）方法来评估STAT5与共激活因子/阻遏物之间的关联。鉴于我们的初步证据表明，对这些相互作用的操纵导致STAT5介导的基因表达和乳腺癌细胞的存活的改变，我们提出的研究与更好地了解人类乳腺癌的病理生理学直接相关，因此可以为这种疾病的新治疗策略提供基础。