A NOVEL GENETIC SELECTION FOR CHROMOSOME TRANSLOCATIONS

染色体易位的新型遗传选择

• 批准号: 6490214
• 负责人: JANET E. LINDSLEY
• 金额: $ 13.59万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6490214
• 关键词: DNA topoisomerases; Saccharomyces cerevisiae; X ray; artificial chromosomes; cell cycle; chromosome translocation; cytogenetics; enzyme activity; fungal genetics; gene expression; gene frequency; genetic disorder diagnosis; genetic mapping; genetic markers; genetic screening; neoplasm /cancer genetics; neoplastic transformation; nucleic acid hybridization; nucleic acid sequence; polymerase chain reaction; pulsed field gel electrophoresis; southern blotting; technology /technique development

Chromosomal translocations are common genetic abnormalities found in both leukemias and solid tumors. These rearrangements often lead to the activation of proto-oncogenes or production of tumor- specific fusion proteins. While much has been learned about the effects of specific translocations on cell proliferation, much less is known about what causes these chromosome rearrangements. While a subset of translocations found in lymphoid malignancies may involve the RAG recombination system, the mechanistic basis for most other translocations remains unknown. One reason for this lack of understanding about the development of translocations compared to other cancer-associated genetic abnormalities (e.g. mismatch repair and nucleotide excision repair deficiencies, aneuploidy, etc.) is the lack of a genetic selection system for translocations in a model organism. This proposal describes the development and use of a system that genetically selects for rare translocations, of the types seen in human tumors, using the yeast Saccharomyces cerevisiae. A set of yeast artificial chromosomes has been constructed that contain chosen sequences of human DNA flanked by genetic markers. In the appropriate yeast strain, translocations whose breakpoints occur within the human DNA sequences can be selected for under a wide variety of growth conditions. This system will be used to answer both specific questions, such as whether DNA topoisomerase II participates in translocations involving the MLL gene, and general questions about what other DNA metabolic or cell cycle checkpoint gene products are required to prevent or cause chromosomal translocations.

染色体易位是白血病和实体瘤中常见的遗传异常。 这些重排通常导致原癌基因的激活或肿瘤特异性融合蛋白的产生。 虽然人们对特定易位对细胞增殖的影响了解很多，但对于导致这些染色体重排的原因却知之甚少。虽然淋巴恶性肿瘤中发现的一部分易位可能涉及 RAG 重组系统，但大多数其他易位的机制基础仍然未知。 与其他癌症相关遗传异常（例如错配修复和核苷酸切除修复缺陷、非整倍性等）相比，对易位的发展缺乏了解的原因之一是模型生物中缺乏易位的遗传选择系统。 该提案描述了一种系统的开发和使用，该系统使用酿酒酵母对人类肿瘤中常见的罕见易位类型进行遗传选择。 一组酵母人工染色体已被构建，其中含有选定的人类 DNA 序列，两侧带有遗传标记。 在适当的酵母菌株中，可以在多种生长条件下选择断点发生在人类 DNA 序列内的易位。 该系统将用于回答两个具体问题，例如DNA拓扑异构酶II是否参与涉及MLL基因的易位，以及有关需要哪些其他DNA代谢或细胞周期检查点基因产物来预防或引起染色体易位的一般问题。