BIOCHEMICAL EVENTS IN PHORBOL ESTER EFFECTS ON NORMAL AND TUMOR CELLS

佛波酯对正常细胞和肿瘤细胞影响的生化事件

• 批准号: 3963055
• 负责人: H L COOPER
• 金额: --
• 依托单位: DIVISION OF CANCER BIOLOGY AND DIAGNOSIS
• 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/3963055
• 关键词: calcium; cell differentiation; cell growth regulation; cell type; cyclic AMP; histocompatibility antigens; human tissue; myelogenous leukemia; neoplasm /cancer immunology; neoplastic cell; oncogenes; phorbols; phosphorylation; platelet activating factor; platelet aggregation; protein kinase; protein kinase C

Studies have continued on the unique phosphoprotein, pp17, which undergoes rapid phosphorylation in HL60 promyelocytic leukemia cells in response to treatment with phorbol ester (TPA). By tryptic peptide analysis of specific proteins recovered from 2-dimensional electrophoretic gels, the nonphosphorylated precursor (p17) of pp17 has been identified. A novel and inexpensive method for measurement of radioactivity in single proteins directly on 2-dimensional gels was devised in this laboratory by R. Braverman. Using this technique, the cellular content of p17 and the rate and extent of its phosphorylation to pp17 after TPA treatment was quantitated. p17 was found to be one of the major cytosolic proteins in HL60 cells (0.5% of total cytosolic protein). About 50% of preexisting p17 is phosphorylated within 15 minutes of addition of TPA to HL60. These findings indicate that phosphorylation of p17 is one of the most rapid, and quantitatively significant biochemical responses to TPA treatment. Since this occurs in the context of abrupt cessation of cell growth and onset of monocytoid differentiation, the possible role of p17 and pp17 in these processes is being explored. The only other phenomenon known to occur in this time frame in this system is the rapid and transitory activation of the c-fos cellular oncogene. The possibility of a functional interrelationship between these two phenomena is being explored. The possible role of p17 and its phosphorylation to pp17 in cell growth regulation in other cell types is also being explored. Preliminary results indicate increased phosphorylation of p17 in lymphoid cells which exhibit reduced cell growth rate in response to serum deprivation.

对独特的磷蛋白pp 17的研究仍在继续， HL 60早幼粒细胞白血病细胞对 用佛波醇酯（TPA）处理。 通过胰蛋白酶肽分析 从二维电泳凝胶中回收的特异性蛋白质， 已经鉴定了pp 17的非磷酸化前体（p17）。 一种新颖且 一种廉价测定单个蛋白质放射性的方法 直接在二维凝胶上的方法是由R. 布雷弗曼 用这种技术，细胞中p17的含量和比率， TPA处理后其磷酸化为pp 17的程度是 定量。 p17蛋白是一种主要的胞浆蛋白， HL 60细胞（占总胞浆蛋白的0.5%）。 大约50%的预先存在的p17 在加入TPA至HL 60的15分钟内磷酸化。 这些 研究结果表明，p17的磷酸化是最快的， 对TPA处理的定量显著的生物化学响应。 以来 这发生在细胞生长突然停止， 单核细胞样分化，p17和pp 17在这些可能的作用， 进程正在探索中。 另一个已知的现象是 在这个系统中的这个时间框架是快速和短暂的激活， c-fos细胞癌基因。 功能性的可能性 正在探讨这两种现象之间的相互关系。 的 p17及其磷酸化产物pp 17在细胞生长中的作用 其他细胞类型的调控也在探索中。 初步结果 表明淋巴样细胞中p17磷酸化增加， 降低细胞生长速率以响应血清剥夺。