title: Relationship between expression of a major apurinic/apyrimidinic endonuclease (APEX nuclease) and susceptibility to genotoxic agents in human glioma cell lines.
abstract: The multifunctional DNA repair enzyme (APEX nuclease) having apurinic/apyrimidinic (AP) endonuclease, 3'-5' exonuclease, DNA 3' repair diesterase and DNA 3'-phosphatase activities is thought to be involved in repair of AP sites and single-strand breaks with 3'-blocked termini. To investigate the biological role of the enzyme, we studied the correlation between APEX AP endonuclease activity in several human glioma cell lines having various degree of its expression and cellular susceptibility to cytotoxic agents such as methyl methanesulfonate (MMS), 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU), cis-diamminedichloroplatinum(II) (CDDP), etoposide (VP-16), hydrogen peroxide (H2O2), hyperthermia and X-ray. The cell lines having lower APEX expression showed higher sensitivity to MMS and H2O2 which are known to induce AP sites and single strand breaks on DNA, respectively. The cellular susceptibility to the other agents tested was not significantly correlated to the APEX expression. The present results are thought to support the notion that APEX nuclease plays an important role on repair of AP sites and single-strand DNA breaks with 3'-blocked termini in mammalian cells.
authors.affiliation: Department of Neurological Surgery, Okayama University Medical School, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ono
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: T
authors.initials: T
authors.lastname: Furuta
authors.forename: T
authors.initials: T
authors.lastname: Ohmoto
authors.forename: K
authors.initials: K
authors.lastname: Akiyama
authors.forename: S
authors.initials: S
authors.lastname: Seki
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D019757:Carbon-Oxygen Lyases; D004260:DNA Repair; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D004351:Drug Resistance; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D005090:Exodeoxyribonucleases / Q000235:genetics / Q000378:metabolism*; D005910:Glioma / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D006358:Hot Temperature; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D009153:Mutagens; D012333:RNA, Messenger / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000528:radiation effects
chemical_list: D000970:Antineoplastic Agents; D009097:Multienzyme Complexes; D009153:Mutagens; D012333:RNA, Messenger; D006861:Hydrogen Peroxide; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; D019757:Carbon-Oxygen Lyases; C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase