ROLE OF TOPOISOMERASE II IN NBQ MEDIATED TUMOR CELL DIFFERENTIATION

拓扑异构酶 II 在 NBQ 介导的肿瘤细胞分化中的作用

• 批准号: 6107344
• 负责人: ADRIANA BAEZ
• 金额: $ 12.07万
• 依托单位: UNIVERSITY OF PUERTO RICO MED SCIENCES
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6107344
• 关键词: DNA damage; DNA topoisomerases; antineoplastics; cell cycle; cell differentiation; chemical cleavage; clone cells; cytotoxicity; densitometry; drug design /synthesis /production; drug screening /evaluation; enzyme inhibitors; flow cytometry; neoplastic cell; nucleic acid sequence; physical chemical interaction; polymerase chain reaction; quinoline analog

3-nitrobenzothiazolo[3,2-a] quinolinium (NBQ) intercalates in DNA and shows a strong potential as antitumor agent. Studies in our laboratory on its mode of action revealed that the cytotoxicity of NBQ is associated with topoisomerase II- mediated DNA strand breaks. Moreover, NBQ significantly enhances in vivo lens regeneration in the adult newt Notophtalmus viridescens, and induces in vitro the differentiation of HL-60 and DFaDu tumor cell lines. NBQ, at non-lethal doses that stimulate differentiation, binds in vitro topoisomerase II to purified DNA. The involvement of topoisomerase II in the cytotoxic and differentiation activities of NBQ, brings into question what is the role of topoisomerase II in the NBQ-induced differentiation. Knowledge of the molecular mechanism(s) through which NBQ induces differentiation, in contrast to its cytotoxic effect, will further a potentially new mode of cancer chemotherapy. To explore this question, we will study the effects of NBQ and eight analogs using a combination of molecular and cellular approaches. Because the DNA sequence localization of the cleavable complex, formed by NBQ and the various analogs, with topoisomerase II should be identical, the comparison of drug effects is more amenable to interpretation. We propose to characterize the cytotoxic activity of the eight NBQ analogues and evaluate athe inhibition f topoisomerase activity. The differentiation ability of each analog will compared to NBQ (80 - 90% HL-60 cells differentiated into the granulocytic series). To understand the mechanism of action of NBQ and analogs, we will evaluate; the formation of protein linked strand breaks in intact cells, the inhibition of topoisomerase activity i vitro, and promotion of chromosomal abnormalities. The effects of NBQ analogs on the cell cycle will be detected at concentration that induce differentiation compared with cytotoxic concentrations. The pattern of topoisomerase II-mediated DNA cleavage stimulated by NBQ will be compared to the cleavage pattern stimulated by NBQ analogs and the topoisomerase II poisons doxorubicin, VP-16 and m-AMSA. Finally, the effects of NBQ analogs will be studied in the resistant HL-60 and m-AMSA. Finally, the effects of NBQ analogs will be studied in the resistant HL-60 cell line (HL-60/NBA), which allows us to study the basis for differences in activity, specially, the induction of differentiation.

3-硝基苯甲酸[3,2-a] quinolinium（NBQ）在DNA和 显示出抗肿瘤剂的强大潜力。 在我们的实验室研究 它的作用方式表明，NBQ的细胞毒性与 拓扑异构酶II-介导的DNA链断裂。 此外，NBQ显着 增强成人newt notophtalmus的体内镜头再生 Viridescens，并在体外诱导HL-60和DFADU的分化 肿瘤细胞系。 NBQ，以刺激分化的非致命剂量， 结合体外拓扑异构酶II与纯化的DNA。 拓扑异构酶II参与细胞毒性和分化 NBQ的活动提出质疑，拓扑异构酶的作用是什么 II在NBQ诱导的分化中。 分子知识 NBQ通过其诱导分化的机制，与之相反 细胞毒性效应将进一步进一步癌症的新模式 化学疗法。 为了探讨这个问题，我们将研究NBQ的影响 以及八个类似物，结合了分子和细胞方法。 因为可裂解复合物的DNA序列定位，由 NBQ和各种类似物，具有拓扑异构酶II应该相同， 药物作用的比较更适合解释。 我们建议 表征八个NBQ类似物的细胞毒性活性和 评估A抑制F拓扑异构酶活性。差异化 每个模拟的能力将与NBQ（80-90％HL -60细胞）进行比较 分为粒细胞系列）。 了解机制 NBQ和类似物的作用，我们将评估； 蛋白质的形成 完整细胞中连接的链断裂，抑制拓扑异构酶 活性I体外，并促进染色体异常。 效果 将在浓度下检测到细胞周期上的NBQ类似物的 与细胞毒性浓度相比，诱导分化。 图案 NBQ刺激的拓扑异构酶II介导的DNA裂解的 与NBQ类似物刺激的裂解模式相比 拓扑异构酶II毒药阿霉素，VP-16和M-​​AMSA。 最后， NBQ类似物的效果将在抗性HL-60和M-AMSA中进行研究。 最后，将在抗性HL-60中研究NBQ类似物的效果 细胞系（HL-60/NBA），这使我们能够研究差异的基础 在活动中，特别是分化的诱导。