ATM KINASE AS A NOVEL TARGET FOR RADIOSENSITIZING AGENTS

ATM 激酶作为放射增敏剂的新靶标

• 批准号: 6643562
• 负责人: Jann N. Sarkaria
• 金额: $ 12.54万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6643562
• 关键词: androstane compound; antineoplastics; ataxia telangiectasia; athymic mouse; cell growth regulation; chromosome inversion; drug design /synthesis /production; drug screening /evaluation; enzyme inhibitors; flow cytometry; gene deletion mutation; peptide library; phosphatidylinositol 3 kinase; radiosensitizer; tissue /cell culture; xenotransplantation

The cell cycle checkpoint activation by un-replicated or damaged DNA triggers a transduction cascade that orchestrates a variety of cellular responses including cell-cycle arrest, DNA repair, and apoptotic death. Several members of the phosphatidylinositol 3-kinase related kinase (PIKK) family, including the Ataxia-Telangiectasia (A-T) syndrome is caused by an inherited defect in both alleles of the ATM gene. Based on the extreme radiation hypersensitivity of individuals affected by A-T small-molecule inhibitors of TM catalytic activity may be useful as a novel radiosensitizing agents. In support of this, we have recently shown that the fungal metabolite, wortmannin, inhibits ATM kinase activity at concentrations that induce significant radiosensitization. The long-term goal of the current research project is to advanced the pre-clinical development of ATM kinase inhibitors as sensitizing agents for use in cancer therapy. In preliminary experiments, we found that wortmannin treatment prior to irradiation of S-phase synchronized cells resulted in a significant prolongation of the G2 delay. By comparing the defects in the G2 checkpoint and associated signal transduction pathways in wortmannin treated cells and cells derived from A-T patients, further insight into the mechanism of wortmannin-mediated radiosensitization will be gained. To demonstrate proof-of-principle for the use of ATM inhibitors in the clinical setting, the efficacy of wortmannin as a radiosensitizer in xenograft system will be examined. To accelerate the identification of novel ATM inhibitors, the catalytic activity of a series of ATM truncation and deletion mutants will be assessed in an effort to identify a catalytically active protein fragment. Such a fragment will then be used in the development of high-throughput screen for ATM kinase inhibitors. The identification of potent, specific inhibitors of ATM may lead to the development of noel therapeutic agents in the treatment of cancer.

通过未复制或损坏的DNA激活细胞周期检查点会触发转导级联，该级联序列策划了各种细胞反应，包括细胞周期停滞，DNA修复和凋亡死亡。磷脂酰肌醇3-激酶相关激酶（PIKK）家族的几个成员，包括催化性 - 凝血症（A-T）综合征是由ATM基因的两个等位基因中的遗传缺陷引起的。基于受TM催化活性的A-T小分子抑制剂影响的个体的极端辐射超敏反应可能是一种新型的放射敏化剂。为了支持这一点，我们最近表明，真菌代谢产物Wortmannin抑制ATM激酶活性在诱导明显的放射敏化的浓度下。当前研究项目的长期目标是提高ATM激酶抑制剂的临床前开发，作为用于癌症治疗的敏化剂。在初步实验中，我们发现在辐照S期同步细胞之前的麦芽汁治疗导致G2延迟显着延长。通过比较G2检查点和相关信号转导途径中的缺陷，将获得对A-T患者的细胞和细胞中的细胞，进一步深入了解WORTMANNIN介导的放射激素化机制。为了证明在临床环境中使用ATM抑制剂的原则证明，将检查磨牙作为放射性敏感剂在异种移植系统中的功效。为了加速新型ATM抑制剂的鉴定，将评估一系列ATM截断和缺失突变体的催化活性，以识别催化活性的蛋白质片段。然后，这种片段将用于开发ATM激酶抑制剂的高通量屏幕。鉴定ATM的有效抑制剂可能导致NOEL治疗剂在癌症治疗中的发展。

项目成果

Inhibition of the mammalian target of rapamycin sensitizes U87 xenografts to fractionated radiation therapy.

• DOI: 10.1016/s0959-8049(02)81193-5
• 发表时间: 2002-12
• 期刊: Cancer research
• 影响因子: 11.2
• 作者: J. Eshleman;B. Carlson;Ann C Mladek;B. D. Kastner;K. Shide;J. Sarkaria

Identifying inhibitors of ATM and ATR kinase activities.

鉴定 ATM 和 ATR 激酶活性的抑制剂。

• DOI: 10.1385/1-59259-380-1:49
• 发表时间: 2003
• 期刊: Methods in molecular medicine.
• 作者: Sarkaria,JannN