【摘要】 p33ING1b是一个较晚发现的肿瘤抑制基因ING1的主要表达形式,但是它在细胞衰老过程中的作用特别是对衰老细胞DNA损伤修复的影响还没有被阐明.本研究首先用2BS细胞构建了细胞衰老模型,通过RTPCR和Western印迹技术证实p33ING1b在衰老细胞中的表达水平下调;然后,通过构建和包装包含p33ING1b基因的腺病毒,将p33ING1b导入年轻和衰老细胞中并使其过表达,用HCR(hostcellreactivation,宿主细胞复活)方法检测年轻细胞和衰老细胞DNA损伤修复能力.实验表明,相对于年轻细胞,p33ING1b过表达使衰老细胞的DNA的损伤修复能力显著增加,说明p33ING1b在衰老细胞中的表达下调与衰老细胞DNA损伤修复能力的下降有关,也进一步证实了p33ING1b在细胞衰老过程中起着十分重要的作用.更多还原

【Abstract】 As one major isoform of ING1, p33 ING1b has been well documented in the past ten years since it was cloned. Previous studies show that p33 ING1b is involved in growth inhibition, apoptosis, chromatin remodeling, DNA repair, tumor suppression and cellular senescence, but its biochemical function and involvement in cellular senescence is still not fully uncharacterized. In this study, we established cellular senescence model and examined the transcription and expression level in senescent and young cells, constructed adenoviruses encoding for p33 ING1b to investigate whether ectopic p33 ING1b has an effect on apoptosis and DNA repair in young and senescent cells. RT-PCR and Western blotting revealed the transcription and expression levels of p33 ING1b in senescent cells are down-regulated contrary to young cells, Host cell reactivation assay suggested adenoviruses-mediated over-expression of p33 ING1b in senescent cells can enhance DNA repair ability in senescent cells dramatically rather than young cells. These results show that decreased expression level of p33 ING1b lead to poor DNA damage repair in senescent cells and may play an important role during cellular senescence.更多还原