Long-patch base excision repair of apurinic/apyrimidinic site DNA is decreased in mouse embryonic fibroblast cell lines treated with plumbagin: involvement of cyclin-dependent kinase inhibitor p21Waf-1/Cip-1.
Molecular interactions among cell cycle and DNA repair proteins have been described, but the impact of many of these interactions on cell cycle control and DNA repair remains unclear. The cyclin-dependent kinase inhibitor, p21, is known to be involved in DNA damage-induced cell cycle arrest and blocking DNA replication and repair. Participation of p21 has been implicated in nucleotide excision repair. However, the role of p21 in the base excision repair (BER) pathway has not been thoroughly studied. In the present investigation, we treated isogenic mouse embryonic fibroblast (MEF) cell lines containing wild-type (MEF-polbeta) or DNA polymerase beta (polbeta) gene-knockout (MEFpolbetaKO) with oxidative DNA-damaging agent, plumbagin, and examined its effect on p21 levels and BER activity. Plumbagin treatment caused a S-G(2)/M phase arrest and cell death of both MEF cell lines, induced p21 levels, and decreased p21-mediated long-patch (LP) BER by blocking DNA ligase activity in the polbeta-dependent pathway and by blocking both FEN1 and DNA ligase activity in polbeta-independent pathway. These findings suggest that plumbagin induced p21 levels play a regulatory role in cell cycle arrest, apoptosis, and polbeta-dependent and -independent LP-BER pathways in MEF cells.
Department of Anatomy and Cell Biology, College of Medicine, The University of Florida, Gainesville 32610, USA.
Aruna S
AS
Jaiswal
Linda B
LB
Bloom
Satya
S
Narayan
D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D019951:DNA Polymerase beta / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair / Q000187:drug effects*; D004622:Embryo, Mammalian / Q000166:cytology; D005347:Fibroblasts / Q000187:drug effects*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009285:Naphthoquinones / Q000494:pharmacology*; D018809:Proliferating Cell Nuclear Antigen / Q000187:drug effects / Q000378:metabolism; D011687:Purines; D011743:Pyrimidines; D017382:Reactive Oxygen Species / Q000378:metabolism
C493957:Cdkn1a protein, mouse; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D009285:Naphthoquinones; D018809:Proliferating Cell Nuclear Antigen; D011687:Purines; D011743:Pyrimidines; D017382:Reactive Oxygen Species; D019951:DNA Polymerase beta; C030986:pyrimidine; C030985:purine; C014758:plumbagin