脆性组氨酸三联体突变体在DNA损伤应答中的作用机制  

Mechanism of Fhit Mutants in DNA Damage Response

作　　者：于芳[1] 绳纪坡[1] 胡宝成[1] 

机构地区：[1]军事医学科学院生物工程研究所,北京100850

出　　处：《生物技术通讯》2013年第2期153-156,共4页Letters in Biotechnology

基　　金：国家自然科学基金(31070760;30770651;30670616)

摘　　要：目的:用建立的稳定表达脆性组氨酸三联体(Fhit)突变体的细胞株,研究Fhit与复制蛋白A(RPA)之间的相互作用对细胞在DNA损伤后的影响。方法:用电离辐射或DNA损伤诱导剂喜树碱处理稳定表达Fhit突变体的阳性细胞株HeLa-FhitA/D/F后,通过流式细胞技术、MTT比色法及克隆形成实验,检测这些细胞系的细胞周期变化情况以及对DNA损伤诱导剂的敏感性。结果:DNA损伤诱导剂处理后,Fhit突变体基因的高表达可以使细胞表现出更强的G2期阻滞及对DNA损伤诱导剂更耐受。结论:Fhit与RPA相互作用的改变影响了细胞对DNA损伤诱导剂的耐受性,为阐明Fhit在维持基因组完整性方面的机理提供了线索。Objective： To explore the role of fragile histidine triad（Fhit） and replication protein A（RPA） interac- tion in mammalian ceils to DNA damage response by using established stable expressed cell lines of human Fhit mutants. Methods： After treatment with ionizing radiation （IR） or camptothecin （CPT）, the stable cell lines HeLa-FhitA/D/F expressing human Fhit mutants were harvested at different time and cell cycles and cell survival fractions were tested by using flow cytometry or MTT and colony-forming assay. Results： The effect of Fhit mu- tant in mammalian cells to the cell cycles and the sensitivities to IR or CTP-indueed DNA damage was identi- fied, it was found that these cells showed stronger G2 checkpoint response to IR and more resistant to CPT-in- dueed killing than Fhit wild type cells. Conclusion： The interaction between Fhit and RPA affects the radiosensi- tivity of cells to DNA damage inducer, it provides a clue to elucidate the mechanism for Fhit maintaining genom- ie integrity.

关 键 词：脆性组氨酸三联体 突变体 复制蛋白A 稳定表达细胞系 DNA损伤应答 

分 类 号：Q25[生物学—细胞生物学] Q78