Transcriptional & cell cycle control by dietary indoles

转录的

• 批准号: 6815112
• 负责人: GARY L FIRESTONE
• 金额: $ 27.41万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-30 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6815112
• 关键词: MCF7 cell; athymic mouse; biological signal transduction; breast neoplasms; cell growth regulation; cell proliferation; chemoprevention; cyclin dependent kinase; genetic promoter element; genetic regulation; genetic transcription; indoles; intermolecular interaction; neoplastic cell; nutrition aspect of cancer; nutrition related tag; plasmids; posttranslational modifications; protein sequence; transcription factor; transfection /expression vector; vegetables

DESCRIPTION (provided by applicant): Indole-3-carbinol (I3C), a naturally occurring compound in vegetables such as cabbage, broccoli and Brussel's sprouts, and its dimerization product 3-3'-diindolylmethane (DIM) are promising chemotherapeutic and chemopreventative agents for human reproductive cancers. We have demonstrated that the direct exposure of human breast cancer cells to I3C or DIM induces a stringent G1 cell cycle arrest through a multistep signaling cascade that controls expression, activity and cellular utilization of key cell cycle components. I3C, but not DIM, down-regulates cyclin dependent kinase-6 (CDK6) expression and promoter activity, whereas, DIM selectively and rapidly stimulates expression and promoter activity of p21Waf1/Cip1, a critical inhibitor of certain CDKs. The indole regulation of cell cycle gene expression result from specific changes in Sp1 transcription factor-promoter interactions. We have recently discovered that I3C, but not DIM, alters the size, composition and subcellular localization (nuclear to cytoplasm) of the CDK2 protein complex, and a novel 85 kDa protein was uncovered that associates with the CDK2 protein complex in an I3C dependent manner. Thus, the transcriptional control of CDK6 and p21Waf1/Cip1, and the posttanslational regulation of CDK2 protein complex utilization are newly defined down-stream targets of the anti-proliferative indole signaling pathway in human breast cancer cells. Our hypothesis is that I3C and DIM induce a G1 cell cycle arrest of human reproductive cancer cells by activating complementary and distinct cascades that that subsequently control the transcription and posttranslational utilization of key cell cycle components. The indole regulated transcription factors, in addition to Spl, that target the CDK6 and p21Waf1/Cip1 promoters will be identified by interactions with indole responsive regions of cell cycle gene promoters, and functionally tested in a cellular text by manipulation of their expression and/or activity. The novel 85 kDa protein that interacts with the CDK2 protein complex in an I3C dependent manner will be defined and characterized for its role in the I3C disruption of the CDK2 protein complex. The actions of the I3C regulated cell cycle components on cancer cell invasion properties, and in the formation of human breast cancer cell-derived tumors will be assessed using in vitro and in vivo strategies. Our collaborative studies represent the first experimental steps necessary to understand the transcriptional and posttranslational mechanisms by which natural indoles control the cell cycle of human breast cancer cells. This information will be particularly valuable to develop new classes of I3C-based therapeutics for reproductive cancers.

描述(由申请人提供)：吲哚-3-甲醇(I3C)是一种天然存在于卷心菜、花椰菜和甘蓝芽等蔬菜中的化合物，其二聚产物3-3‘-二吲哚甲烷(DIM)是治疗人类生殖癌症的有前途的化疗和化学预防药物。我们已经证明，人乳腺癌细胞直接暴露在I3C或DIM中，通过控制关键细胞周期成分的表达、活性和细胞利用的多步信号级联，诱导严格的G1细胞周期停滞。I3C，但不是DIM，下调细胞周期蛋白依赖性激酶-6(CDK6)的表达和启动子活性，而DIM选择性和快速地刺激某些CDKs的关键抑制因子p21Waf1/Cip1的表达和启动子活性。细胞周期基因表达的吲哚调节是Sp1转录因子-启动子相互作用特异性变化的结果。我们最近发现，I3C但不是Dim改变了CDK2蛋白复合体的大小、组成和亚细胞定位(核到细胞质)，并发现了一个新的85 kDa蛋白，它以I3C依赖的方式与CDK2蛋白复合体结合。因此，CDK6和p21Waf1/Cip1的转录调控以及CDK2蛋白复合体利用的翻译后调控是人乳腺癌细胞抗增殖吲哚信号通路下游的新靶点。 我们的假设是，I3C和DIM通过激活互补的和不同的级联反应来诱导人类生殖癌细胞的G1期停滞，这些级联反应随后控制关键细胞周期成分的转录和翻译后利用。除SPL外，针对CDK6和p21Waf1/Cip1启动子的吲哚调节转录因子将通过与细胞周期基因启动子的吲哚响应区的相互作用来识别，并通过操纵它们的表达和/或活性在细胞文本中进行功能测试。新的85 kDa蛋白以I3C依赖的方式与CDK2蛋白复合体相互作用，将被定义和表征其在I3C破坏CDK2蛋白复合体中的作用。将使用体外和体内策略评估I3C调节的细胞周期成分对癌细胞侵袭特性以及在人类乳腺癌细胞来源的肿瘤形成中的作用。我们的合作研究是理解天然吲哚控制人类乳腺癌细胞细胞周期的转录和翻译后机制所必需的第一个实验步骤。这些信息对于开发新的基于I3C的生殖癌症治疗方法将特别有价值。