title: Human POLD1 modulates cell cycle progression and DNA damage repair.
abstract: BACKGROUND
  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.
  
  
  METHODS
  HEK293 cells were transfected with POLD1 expression plasmid or shRNA, cell proliferation, cell cycle progression, and DNA synthesis in HEK293 cells were analyzed.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  Our results suggest that human POLD1 plays important role in the regulation of cell cycle progression and DNA damage repair.
authors.affiliation: Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China. jing_song@163.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China. hpxia_1998@163.com.
authors.forename: Ping
authors.initials: P
authors.lastname: Hong
authors.affiliation: Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China. westpoint0722@gmail.com.
authors.forename: Chengeng
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China. yqi_zhang@126.com.
authors.forename: Yueqi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China. peichang_wang@163.com.
authors.forename: Jinling
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Clinical Laboratory, Xuanwu Hospital Capital Medical University, No.45 Changchun Street, Xicheng District, Beijing, 100053, China. peichang_wang@163.com.
authors.forename: Peichang
authors.initials: P
authors.lastname: Wang
mesh_terms: D002453:Cell Cycle; D059447:Cell Cycle Checkpoints; D049109:Cell Proliferation; D016922:Cellular Senescence; D004247:DNA / Q000096:biosynthesis / Q000235:genetics; D004249:DNA Damage; D004258:DNA Polymerase III / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D015536:Down-Regulation; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: D034741:RNA, Small Interfering; D004247:DNA; C434055:POLD1 protein, human; D004258:DNA Polymerase III