Song Jing, Hong Ping, Liu Chengeng, Zhang Yueqi, Wang Jinling, Wang Peichang
Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China.
BMC Biochem. 2015 Jun 19;16:14. doi: 10.1186/s12858-015-0044-7.
The activity of eukaryotic DNA polymerase delta (Pol δ) plays an essential role in genome stability through its effects on DNA replication and repair. The p125 catalytic subunit of Pol δ is encoded by POLD1 gene in human cells. To clarify biological functions of POLD1, we investigated the effects of POLD1 overexpression or downregulation on cell proliferation, cell cycle progression, DNA synthesis and oxidative DNA damage induced by H2O2.
HEK293 cells were transfected with POLD1 expression plasmid or shRNA, cell proliferation, cell cycle progression, and DNA synthesis in HEK293 cells were analyzed.
HEK293 cells were transfected with POLD1 expression plasmid or shRNA. POLD1 downregulation by shRNA suppressed cell proliferation, cell cycle progression, and DNA synthesis in HEK293 cells. However, POLD1 overexpression had no significant effects on these processes. Finally, comet assay showed that POLD1 downregulation led to increased DNA damage.
Our results suggest that human POLD1 plays important role in the regulation of cell cycle progression and DNA damage repair.
真核生物DNA聚合酶δ（Pol δ）的活性通过其对DNA复制和修复的作用，在基因组稳定性中发挥着至关重要的作用。Pol δ的p125催化亚基由人类细胞中的POLD1基因编码。为阐明POLD1的生物学功能，我们研究了POLD1过表达或下调对细胞增殖、细胞周期进程、DNA合成以及过氧化氢诱导的氧化性DNA损伤的影响。
用POLD1表达质粒或短发夹RNA（shRNA）转染人胚肾293（HEK293）细胞，分析HEK293细胞中的细胞增殖、细胞周期进程和DNA合成。
用POLD1表达质粒或shRNA转染HEK293细胞。shRNA介导的POLD1下调抑制了HEK293细胞的增殖、细胞周期进程和DNA合成。然而，POLD1过表达对这些过程无显著影响。最后，彗星试验表明POLD1下调导致DNA损伤增加。
我们的结果表明，人类POLD1在细胞周期进程调控和DNA损伤修复中起重要作用。
