Deciphering pathways involved in topoisomerase II turnover

破译拓扑异构酶 II 周转涉及的途径

• 批准号: 10552113
• 负责人: Junjie Chen
• 金额: $ 50.3万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2027-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10552113
• 关键词: Active Sites; Agreement; Antineoplastic Agents; Biology; Bypass; CRISPR screen; Cell Cycle Inhibition; Cell Cycle Progression; Cell Death; Cell Proliferation; Cell Survival; Cells; Chromatin; Chromosome Segregation; Complex; DNA; DNA Adduction; DNA Adducts; DNA Damage; DNA Repair; DNA Topoisomerases; DNA lesion; DNA strand break; Ensure; Enzymes; Etoposide; Eukaryota; Excision; Fission Yeast; Genes; Genetic Transcription; Human; Knock-out; Lesion; Link; Literature; Mammalian Cell; Mediating; Pathway interactions; Poison; Process; Prokaryotic Cells; Proteins; Reaction; Regulation; Research Personnel; Resistance; Role; Rotation; SPO11 gene; Signal Transduction; Somatic Cell; Stress; Superhelical DNA; TOP1 gene; TOP2A gene; Testing; Therapeutic; Topoisomerase; Topoisomerase II; Topoisomerase III; Type I DNA Topoisomerases; Tyrosine; Vertebral column; Work; cancer therapy; experimental study; follow-up; neoplastic cell; protein protein interaction; repaired; response; treatment response; whole genome

PROJECT SUMMARY DNA topoisomerases are types of enzymes that can specifically resolve topological stresses by transiently introducing strand breaks into DNA molecules and enabling the rotation of the supercoiled DNA strand. Mammalian cells encode two types of topoisomerases: type I topoisomerases (TOP1, TOP1mt, TOP3A, and TOP3B), which introduce single strand breaks into DNA, and type II topoisomerases (TOP2A, TOP2B, and SPO11), which introduce double strand breaks (DSBs) into DNA. This proposal focuses on type II topoisomerases, i.e. TOP2A/2B, in human somatic cells. During cleavage reaction, the tyrosine in the catalytic active site of TOP2 is covalently linked to the DNA backbone and forms the so-called topoisomerase II cleavage complex (TOP2cc). Under normal conditions, TOP2cc forms transiently and is not detectable. However, a wide variety of topoisomerase poisons, including etoposide, have been developed and used as chemotherapeutic drugs for cancer treatment. Mechanistically, etoposide acts to stabilize TOP2cc, which eventually lead to DNA strand breaks and kill tumor cells. While many investigators including us investigated TOP2-induced DNA lesions and how they can be repaired by different repair pathways, this proposal focuses on a new concept that cells have evolved distinct pathways to avoid and limit DNA lesions induced by TOP2. In this proposal, we will determine mechanistically how several unique TOP2 regulators act together to avoid DNA damage and therefore promote cell survival. Results from these studies are critically important for the understanding of therapeutic response to etoposide and other anti-cancer agents. .

项目摘要 DNA拓扑异构酶是一类可以通过瞬时降解来特异性地解决拓扑应力的酶。 在DNA分子中引入链断裂并使超螺旋DNA链能够旋转。 哺乳动物细胞编码两种类型的拓扑异构酶：I型拓扑异构酶（TOP1、TOP1 mt、TOP 3A和TOP 3B）。 T0 P3 B），其将单链断裂引入DNA中，和II型拓扑异构酶（T0 P2 A、T0 P2B和T0 P3 B），其将单链断裂引入DNA中。 SPO 11），它将双链断裂（DSB）引入DNA。本提案侧重于第二类 拓扑异构酶，即TOP 2A/2B。 在切割反应期间，TOP 2的催化活性位点中的酪氨酸共价连接到 DNA骨架，并形成所谓的拓扑异构酶II切割复合物（TOP2 cc）。在正常 在这种条件下，TOP2 cc瞬时形成并且不可检测。然而，各种各样的拓扑异构酶毒药， 包括依托泊苷已经被开发并用作癌症治疗的化疗药物。 从机制上讲，依托泊苷起到稳定TOP 2cc的作用，最终导致DNA链断裂并杀死肿瘤细胞。 细胞 虽然包括我们在内的许多研究人员研究了TOP2诱导的DNA损伤以及它们是如何被破坏的， 通过不同的修复途径进行修复，该提案侧重于一个新的概念，即细胞已经进化出不同的修复途径。 避免和限制TOP2诱导的DNA损伤。在本提案中，我们将机械地确定 几种独特的TOP2调节剂如何共同作用以避免DNA损伤，从而促进细胞存活。 这些研究的结果对于理解依托泊苷的治疗反应至关重要 和其他抗癌药物。 .