Involvement of DNA polymerase beta in repairing oxidative damages induced by antitumor drug adriamycin

• Published in: Toxicology and applied pharmacology Vol. 246; no. 3; pp. 163 - 170
• Main Authors: Liu, Shukun, Wu, Mei, Zhang, Zunzhen
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.08.2010; Elsevier
• Subjects: Adriamycin; ANIMAL CELLS; Animals; ANTI-INFECTIVE AGENTS; ANTIBIOTICS; Antineoplastic Agents - pharmacology; ANTINEOPLASTIC DRUGS; APOPTOSIS; Base excision repair; Biological and medical sciences; BIOLOGICAL RECOVERY; BIOLOGICAL REPAIR; Cell Line; CHEMICAL REACTIONS; CONNECTIVE TISSUE CELLS; DAMAGE; DNA; DNA Breaks - drug effects; DNA Damage - drug effects; DNA Damage - genetics; DNA DAMAGES; DNA polymerase beta; DNA Polymerase beta - deficiency; DNA Polymerase beta - genetics; DNA Polymerase beta - metabolism; DNA REPAIR; DNA Repair - drug effects; DNA Repair - genetics; DOXORUBICIN; Doxorubicin - pharmacology; Drug Hypersensitivity - genetics; Drug Hypersensitivity - metabolism; Drug resistance; DRUGS; EMBRYOS; ENZYMES; EXCISION REPAIR; FIBROBLASTS; Fibroblasts - drug effects; Fibroblasts - metabolism; GENE MUTATIONS; Medical sciences; Mice; Mutation - drug effects; Mutation - genetics; MUTATIONS; NUCLEIC ACIDS; ORGANIC COMPOUNDS; OXIDATION; Oxidative Stress - drug effects; Oxidative Stress - genetics; Oxidative Stress - physiology; OXIDOREDUCTASES; PROTEINS; RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS; Reactive oxygen species; Reactive Oxygen Species - metabolism; REPAIR; SOMATIC CELLS; STRAND BREAKS; SUPEROXIDE DISMUTASE; Superoxide Dismutase - genetics; Superoxide Dismutase - metabolism; TOXICITY; Toxicology; pol β; MEFs; Reactive oxygen species; SSB; Adriamycin; SOD; OTM; ADM; MTT; Drug resistance; Base excision repair; BER; DCFH-DA; ROS; DNA polymerase beta; hprt; Antineoplastic agent; Oxidative stress; Doxorubicin; Beta; Isomerases; Dicotyledones; Angiospermae; Mechanism of action; Drug; DNA topoisomerase (ATP-hydrolysing); Treatment resistance; Enzyme; Transferases; Enzyme inhibitor; Nucleotide excision repair; Topoisomerase II inhibitor; Chenopodiaceae; Nucleotidyltransferases; Antibiotic; Anthracyclins; Spermatophyta; DNA-directed DNA polymerase
• ISSN: 0041-008X; 1096-0333
• DOI: 10.1016/j.taap.2010.05.011

Adriamycin (ADM) is a widely used antineoplastic drug. However, the increasing cellular resistance has become a serious limitation to ADM clinical application. The most important mechanism related to ADM-induced cell death is oxidative DNA damage mediated by reactive oxygen species (ROS). Base excision repair (BER) is a major pathway in the repair of DNA single strand break (SSB) and oxidized base. In this study, we firstly applied the murine embryo fibroblasts wild-type (pol β +/+) and homozygous pol β null cell (pol β −/−) as a model to investigate ADM DNA-damaging effects and the molecular basis underlying these effects. Here, cellular sensitivity to ADM was examined using colorimetric assay and colony forming assay. ADM-induced cellular ROS level and the alteration of superoxide dismutase (SOD) activity were measured by commercial kits. Further, DNA strand break, chromosomal damage and gene mutation were assessed by comet assay, micronucleus test and hprt gene mutation assay, respectively. The results showed that pol β −/− cells were more sensitive to ADM compared with pol β +/+ cells and more severe SSB and chromosomal damage as well as higher hprt gene mutation frequency were observed in pol β −/− cells. ROS level in pol β −/− cells increased along with decreased activity of SOD. These results demonstrated that pol β deficiency could enable ROS accumulation with SOD activity decrease, further elevate oxidative DNA damage, and subsequently result in SSB, chromosome cleavage as well as gene mutation, which may be partly responsible for the cytotoxicity of ADM and the hypersensitivity of pol β −/− cells to ADM. These findings suggested that pol β is vital for repairing oxidative damage induced by ADM.