Investigate the Role of Ikbkap/ Elp1 in Genomic Instability
| Autor: | Huan-Yi Tseng, 曾煥義 |
|---|---|
| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 Genomic instability refers to an increased tendency of alterations in the genome during cell cycle progression, and likely contributes to the development of many cancers. To faithfully transmit genetic information to the progeny, efficient DNA repair pathways are required for the maintenance of genomic stability. Ikbkap gene encodes IKAP/Elp1, which functions as a scaffold subunit of the Elongator complex (Elp1-6). The Elongator complex was initially described as an RNA polymerase II-associated transcription elongation factor, but it has been shown later to be involved in a variety of cellular functions through regulation of histone acetylation and tRNA modification. A previous study has shown that Ikbkap regulates meiotic synapsis, double strand break (DSB) repair and recombination during male meiotic progression. Downregulation of DNA repair-related genes was observed in Ikbkap deficient testes, suggesting that Ikbkap plays a crucial role in DNA damage response (DDR) in germ cells. To investigate whether Ikbkap maintains genomic stability in somatic cells, we deleted Ikbkap in mouse embryonic fibroblasts (MEFs). Comet assays show that Ikbkap-/- MEFs are hypersensitive to DNA damage, like -irradiation. Ikbkap-/- MEFs exhibited a proliferative impediment in response to -irradiation. In addition, a significant accumulation of chromosomal abnormalities, including breaks was observed in Ikbkap-/- MEFs compared to controls. Although apoptotic rate was unaffected in Ikbkap-/- MEFs one day post -irradiation, these data shows that IKAP function is essential for the ability to survive DNA damage, and implicating IKAP in repair in U-2 OS cells. Furthermore, we revealed that Ikbkap is required for DNA repair by homologous recombination (HR), but not non-homologous end joining (NHEJ) using U-2 OS cell lines harbouring a green fluorescent protein reporter for DSB repair. These finding define a function of Ikbkap in DNA repair. Further investigation will be focused on the underlying DNA repair mechanisms. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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