The Role of BCR/ABL in Regulating DNA Repair

BCR/ABL 在调节 DNA 修复中的作用

基本信息

批准号：
7410071
负责人：
MARTIN CARROLL
金额：
$ 24.65万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-03-15 至 2010-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7410071
关键词：
ATM deficient ATM function Address Aftercare Animal Model Animals Aphidicolin Apoptotic Biology Blast Phase Bone Marrow Transplantation Cell Line Cell Nucleus Cells Chromosomal Instability Chromosomal Rearrangement Chromosomal translocation Chronic Collaborations Complex Cytoplasm DNA Damage DNA Double Strand Break DNA Modification Process DNA Repair DNA biosynthesis DNA chemical synthesis DNA replication fork Defect Disease Disruption Etoposide Event Family Future Genomic Instability Genotoxic Stress Genotype Human Human Cell Line Impairment Lead Malignant - descriptor Malignant Neoplasms Modeling Molecular Mus Myeloid Cells Nuclear Oncogenes Phase Phenotype Phosphorylation Phosphotransferases Probability Protein Tyrosine Kinase Proteins Research Personnel Role Signal Transduction Spectral Karyotyping Staging Stimulation of Cell Proliferation Syndrome System TP53 gene Testing Tetracycline Tetracyclines Topoisomerase II abl Oncogene base bcr-abl Fusion Proteins carcinogenesis chemotherapeutic agent ds-DNA in vivo insight irradiation knockout animal leukemia novel prevent programs promoter research study response v-src Oncogenes

项目摘要

DESCRIPTION (provided by applicant): Chronic myelogeneous leukemia (CML) is a two stage disease associated with expression of the BCR/ABL tyrosine kinase protein. Experiments in animals and humans have demonstrated that BCR/ABL is clearly responsible for the hyper-proliferation associated with chronic stage CML. However whether BCR/ABL expression directly causes blast crisis, and if so by what mechanism, is unknown. We hypothesize that BCR/ABL modulates the response to DNA damage, thus leading to a state of genomic instability. In support of this hypothesis, we have found that 1) BCR/ABL translocates from the cytoplasm to the nucleus after genotoxic stress; 2) BCR/ABL inhibits the repair of DNA double strand damage after etoposide and leads to a defect in an intra-S phase checkpoint causing a radioresistant DNA synthesis (RDS) phenotype; and 3) BCR/ABL disrupts ATR dependent signal transduction, characterized by the lack of phosphorylation of Chk1 and by the inability of BCR/ABL expressing cells to inactivate the cdc7/Dbf4 regulatory kinase after treatment with etoposide. Taken together, these exciting results show that BCR/ABL expression inhibits activation of ATR, leading to continued DNA synthesis during S phase. We hypothesize that such persistent DNA replication forks would collide with topoisomerase II/etoposide complexes, leading to increased DNA double strand breaks and the formation of chromosomal translocations. In order to confirm and extend this hypothesis, we propose to: 1) determine if BCR/ABL induces permanent chromosomal changes by studying cells using spectral karyotyping; 2) determine if BCR/ABL alters other functions of the ATR protein; and 3) determine the mechanism whereby BCR/ABL disrupts ATR function. Finally, we propose to develop animal models of CML blast crisis to confirm our hypotheses in vivo. Through these multiple approaches, we propose to document and elucidate this novel mechanism of CML progression induced by the BCR/ABL oncogene. More generally, we believe that these studies, based on the fundamental biology of the CML model, may provide insights into the molecular mechanisms of multi-stage carcinogenesis and establish paradigms for future studies of carcinogenesis in diverse systems and diseases.

描述（由申请人提供）：慢性粒细胞白血病（CML）是与 BCR/ABL 酪氨酸激酶蛋白表达相关的两阶段疾病。动物和人类实验表明，BCR/ABL 显然是与慢性期 CML 相关的过度增殖的原因。然而，BCR/ABL 表达是否直接导致急变，以及如果是通过什么机制，尚不清楚。我们假设 BCR/ABL 调节对 DNA 损伤的反应，从而导致基因组不稳定状态。为了支持这一假设，我们发现：1）BCR/ABL 在基因毒性应激后从细胞质易位到细胞核； 2) BCR/ABL抑制依托泊苷后DNA双链损伤的修复，导致S期内检查点缺陷，导致抗辐射DNA合成（RDS）表型； 3) BCR/ABL 破坏 ATR 依赖性信号转导，其特征是 Chk1 缺乏磷酸化，并且 BCR/ABL 表达细胞在依托泊苷处理后无法灭活 cdc7/Dbf4 调节激酶。总而言之，这些令人兴奋的结果表明 BCR/ABL 表达抑制 ATR 的激活，导致 S 期持续 DNA 合成。我们假设这种持久的 DNA 复制叉会与拓扑异构酶 II/依托泊苷复合物碰撞，导致 DNA 双链断裂增加和染色体易位的形成。为了证实和扩展这一假设，我们建议：1）通过使用光谱核型分析研究细胞来确定BCR/ABL是否诱导永久性染色体变化； 2) 确定BCR/ABL是否改变ATR蛋白的其他功能； 3) 确定 BCR/ABL 破坏 ATR 功能的机制。最后，我们建议开发 CML 急变的动物模型，以在体内证实我们的假设。通过这些多种方法，我们建议记录并阐明 BCR/ABL 癌基因诱导的 CML 进展的这种新机制。更一般地说，我们相信这些基于 CML 模型的基础生物学的研究可以为多阶段癌发生的分子机制提供见解，并为未来研究不同系统和疾病的癌发生建立范例。