SIGNAL TRANSDUCTION EVENTS AND THE REGULATION OF CELL GROWTH

信号转导事件和细胞生长的调节

• 批准号: 5201306
• 负责人: J B TREPEL
• 金额: --
• 依托单位: DIVISION OF CANCER TREATMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/5201306
• 关键词: HMG coA reductases; biological signal transduction; cell biology; cell growth regulation; cellular oncology; drug design /synthesis /production; genetic regulation; glycosylation; hormone related neoplasm /cancer; immunoprecipitation; lovastatin; posttranslational modifications; prostate neoplasms; transcription factor; tumor suppressor genes

This project is designed to increase our understanding of cancer cell biology, with an emphasis on hormone-refractory prostate cancer, and to develop a new approach to cancer treatment through the study of growth- regulatory signal transduction events. This work is currently focused on (1) novel aspects of the regulation of cancer cell growth by the retinoblastoma gene product, and (2) the regulation of transcription factors and signal transducting proteins by a unique form of O- glycosylation. The retinoblastoma protein is currently thought to function only in the cell nucleus and only in the GI phase of the cell cycle. In contrast, we found that the retinoblastoma protein is prominently localized in the cell cytoplasm during logarithmic growth. Our data show that this peripheral localization is masked in most studies of the Rb protein because the antibody used only detects the nuclear form of Rb. Unexpectedly, using confocal microscopy and coimmuno-precipitation techniques we found that peripheral Rb is associated with the cell cytoskeleton, and that peripheral Rb protein is localized in the growing tip of logarithmic phase cells. These data suggest a new model of tumor suppressor gene function, in which the tumor suppressor gene product registers cell-cell interaction and sends a growth arrest signal to the nucleus. While studying the anticancer action of the HMG-CoA reductase inhibitor lovastatin we identified a new posttranslational modification of the Rb protein- the addition of O-linked N-acetylglucosamine (O-GlcNAc addition). We found that lovastatin greatly increased the amount of O-GlcNAc modification of the Rb protein, dramatically blocked Rb phosphorylation and markedly changed Rb subcellular distribution. These studies identify O-GlcNAc addition as a new target in anticancer drug development and lovastatin as the first example of a drug that regulates O-GlcNAc metabolism. We have established a cooperative agreement with the British biotechnology company Oxford GlycoSystems, aimed at developing new carbohydrate-directed anticancer drugs.

该项目旨在增加我们对癌细胞的了解 生物学，重点是激素难治性前列腺癌，并 通过生长研究开发一种新的癌症治疗方法 调节信号转导事件。这项工作目前的重点是 (1) 调节癌细胞生长的新方面 视网膜母细胞瘤基因产物，以及（2）转录调控 因子和信号转导蛋白通过独特形式的 O- 糖基化。目前认为视网膜母细胞瘤蛋白的功能 仅在细胞核中并且仅在细胞周期的GI阶段。在 相比之下，我们发现视网膜母细胞瘤蛋白显着 在对数生长过程中定位于细胞的细胞质中。我们的数据显示 大多数 Rb 研究都掩盖了这种外周定位 蛋白质，因为所使用的抗体仅检测 Rb 的核形式。 出乎意料的是，使用共聚焦显微镜和共免疫沉淀 我们发现外周 Rb 与细胞相关 细胞骨架，外周 Rb 蛋白位于生长中 对数期细胞的尖端。这些数据提出了一种新的肿瘤模型 抑制基因功能，其中肿瘤抑制基因产物 记录细胞间的相互作用并向细胞发送生长停滞信号 核。 研究 HMG-CoA 还原酶抑制剂的抗癌作用 洛伐他汀 我们发现了 Rb 的新翻译后修饰 蛋白质-添加O-连接的N-乙酰氨基葡萄糖（O-GlcNAc 添加）。 我们发现洛伐他汀大大增加了 O-GlcNAc 的量 修饰 Rb 蛋白，显着阻断 Rb 磷酸化 并显着改变了 Rb 的亚细胞分布。这些研究确定 O-GlcNAc 添加作为抗癌药物开发的新靶点 洛伐他汀是调节 O-GlcNAc 药物的第一个例子 代谢。我们与英国建立了合作协议 生物技术公司 Oxford GlycoSystems，旨在开发新的 碳水化合物导向的抗癌药物。