Examining the cell cycle-dependence of progesterone receptor activity

检查孕酮受体活性的细胞周期依赖性

• 批准号: 8554765
• 负责人: LINDSEY Starr Trevino
• 金额: $ 0.9万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2013-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8554765
• 关键词: Antibodies; Binding; Breast; Breast Cancer Cell; Cancer cell line; Cell Cycle; Cell Proliferation; Cells; Chemicals; Cyclin A; Cytoplasm; DNA; Data; Dependence; Epithelial Cells; Etiology; Future; Gene Expression; Genes; Genetic Transcription; Growth; Hormones; Immunofluorescence Immunologic; In Vitro; Investigation; Link; MAP Kinase Gene; Mammary Neoplasms; Mammary Tumorigenesis; Mammary gland; Mediating; Microscopy; Nuclear Translocation; Pathway interactions; Phase; Phosphotransferases; Play; Progesterone; Progesterone Receptors; Progestins; Protein Isoforms; Receptor Signaling; Recruitment Activity; Regulation; Reporter Genes; Research; Residual state; Role; S Phase; Serum; Signal Pathway; Signal Transduction; Small Interfering RNA; T47D; Testing; U-0126; base; chromatin modification; cyclin A2; high throughput analysis; high throughput screening; inhibitor/antagonist; malignant breast neoplasm; mammary gland development; new therapeutic target; novel; paracrine; progesterone receptor A; progesterone receptor B; progesterone receptor negative; promoter; receptor binding; receptor function; response; therapeutic target; tumor

DESCRIPTION (provided by applicant): Recent studies have suggested that progestins play a role in the etiology of breast cancer; however, the mechanisms by which progestins promote tumor formation/progression have not been defined. Progestin action is mediated by the progesterone receptor (PR), which has been shown to mediate both growth stimulatory and growth inhibitory effects of progestins in breast cancer cell lines. These observations highlight the complexity of PR signaling in breast cancer and the need for further study of the regulation of PR function. Studies of PR target gene expression in breast cancer cells are typically performed with cells grown under serum conditions that arrest them in G1, and our previous studies suggest that PR activity is likely to have unique activities in the various phases of the cell cycle, possibly through differential co-regulator recruitment. Our previous studies have also shown that nuclear translocation of PR is different across the cell cycle, with a greater amount of translocation in S-phase, compared to G2/M. This observation suggests that rapid signaling, which does not require PR binding to DNA, might be highest in G1 or G2/M where residual PR is found in the cytoplasm. Furthermore, our studies suggest that cyclin A/Cdk2/Cdk1 activity plays a role in S-phase gene expression. I will determine whether PR activity differs as a function of cell cycle by 1) using microarrays to identify genes that are differentially expressed across the cell cycle, 2) assessing whether PR-induced rapid signaling is cell cycle-dependent and 3) depleting cyclin A2 using siRNA or by using Cdk1/2 inhibitors to ask whether S-phase genes are preferentially sensitive to cyclin A/Cdk activity. I will also utilize novel, high througput microscopy analyses to 1) perform an immunofluorescence screen to identify novel PR co-regulators, 2) determine whether recruitment of these co-regulators differs as a function of cell cycle, and 3) examine the effects of cell signaling and Cdk-dependent pathways on co-regulator recruitment using MAPK and Cdk inhibitors. Collectively, these studies will contribute to our knowledge of the regulation of PR activity. Understanding how PR is regulated in breast cancer is important because PR mediates breast cancer cell proliferation directly by regulating target gene expression and indirectly through cross-talk with other mitogenic cell signaling pathways. Investigation of the factors necessary for PR activity may eventually unveil potential therapeutic targets for breast cancer.

描述(申请人提供)：最近的研究表明孕激素在乳腺癌的病因学中起作用；然而，孕激素促进肿瘤形成/进展的机制还没有确定。孕激素的作用是由孕激素受体(PR)介导的，孕激素受体在乳腺癌细胞系中既有促生长作用，又有生长抑制作用。这些观察结果突出了PR信号在乳腺癌中的复杂性，以及对PR功能调节的进一步研究的必要性。对乳腺癌细胞PR靶基因表达的研究通常是在血清条件下生长的细胞，使其滞留在G1期，我们之前的研究表明，PR活性可能在细胞周期的不同阶段具有独特的活动，可能是通过不同的辅助调节因子招募。我们以前的研究也表明，PR在整个细胞周期中的核转位是不同的，与G2/M相比，S期的转位更多。这一观察表明，不需要PR与DNA结合的快速信号可能在G1或G2/M最高，因为在细胞质中发现了残留的PR。此外，我们的研究表明，细胞周期蛋白A/CDK2/CDK1活性在S期基因表达中起作用。我将通过以下几个方面确定PR活性是否随着细胞周期的变化而不同：1)使用微阵列来确定在整个细胞周期中差异表达的基因；2)评估PR诱导的快速信号是否依赖于细胞周期；3)使用siRNA或通过使用CDK1/2抑制剂来耗尽Cyclin A2，以询问S期的基因是否对Cyclin A/CDK活性优先敏感。我还将利用新颖的高通量显微镜分析来1)进行免疫荧光筛选以确定新的PR协同调节因子，2)确定这些协同调节因子的招募是否作为细胞周期的函数而不同，以及3)使用MAPK和CDK抑制剂检测细胞信号和CDK依赖的通路对协同调节因子招募的影响。总而言之，这些研究将有助于我们了解公关活动的调控。了解PR在乳腺癌中是如何调控的非常重要，因为PR通过调节靶基因的表达直接调节乳腺癌细胞的增殖，并通过与其他有丝分裂细胞信号通路的相互作用间接调节乳腺癌细胞的增殖。对PR活性的必要因素的研究可能最终揭示乳腺癌的潜在治疗靶点。