Department of Clinical Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, People's Republic of China.
Department of Clinical Laboratory, The Hospital of Shunyi District Beijing, Beijing, People's Republic of China.
Mol Genet Genomic Med. 2020 Aug;8(8):e1280. doi: 10.1002/mgg3.1280. Epub 2020 May 20.
Fanconi anemia (FA) is a rare recessive disease characterized by DNA damage repair deficiency, and DNA polymerase δ (whose catalytic subunit is encoded by POLD1, also known as CDC2) is closely related to DNA damage repair. Our previous study identified a novel POLD1 missense mutation c.56G>A (p. Arg19>His) in FA family members. However, the function of the POLD1 missense mutation is currently unknown. This study aimed to uncover the biological function of the POLD1 missense mutation.
Stable cell lines overexpressing wild-type POLD1 or mutant POLD1 (c.56G>A, p.Arg19His) were constructed by lentivirus infection. Cell growth curve analysis, cell cycle analysis, and a comet assay were used to analyze the function of the POLD1 mutation.
The growth and proliferative ability of the cells with POLD1 mutation was decreased significantly compared with those of the wild-type cells (Student's t test, p < .05). The percentage of cells in the G0/G1 phase increased, and the percentage of cells in the S phase decreased significantly when POLD1 was mutated (Student's t test, p < .05). Moreover, the Olive tail moment value of the cells with the POLD1 mutation was significantly higher than that of the cells with wild-type POLD1 after H O treatment.
The POLD1 mutation inhibited cell proliferation, slowed cell cycle progression, and reduced DNA damage repair.
范可尼贫血（FA）是一种罕见的隐性疾病，其特征是 DNA 损伤修复缺陷，而 DNA 聚合酶 δ（其催化亚基由 POLD1 编码，也称为 CDC2）与 DNA 损伤修复密切相关。我们之前的研究在 FA 家族成员中发现了一种新型 POLD1 错义突变 c.56G>A（p.Arg19>His）。然而，POLD1 错义突变的功能目前尚不清楚。本研究旨在揭示 POLD1 错义突变的生物学功能。
通过慢病毒感染构建过表达野生型 POLD1 或突变型 POLD1（c.56G>A，p.Arg19His）的稳定细胞系。通过细胞生长曲线分析、细胞周期分析和彗星试验分析 POLD1 突变的功能。
与野生型细胞相比，携带 POLD1 突变的细胞的生长和增殖能力显著下降（Student's t 检验，p<.05）。当 POLD1 发生突变时，G0/G1 期细胞的比例显著增加，而 S 期细胞的比例显著减少（Student's t 检验，p<.05）。此外，在 H2O2 处理后，携带 POLD1 突变的细胞的 Olive 尾巴矩数值明显高于携带野生型 POLD1 的细胞。
POLD1 突变抑制细胞增殖、减缓细胞周期进程并降低 DNA 损伤修复。
