title: Poly(ADP-ribose) Glycohydrolase deficiency sensitizes mouse ES cells to DNA damaging agents.
abstract: Poly(ADP-ribose) glycohydrolase (Parg) is the main enzyme for degradation of poly(ADP-ribose) by splitting ribose-ribose bonds. Parg-deficient (Parg(+/-) and Parg(-/-)) mouse ES cell lines have been established by disrupting both alleles of Parg exon 1 through gene-targeting. A transcript encoding a full length isoform of Parg was eliminated and only low amounts of Parg isoforms were detected in Parg(-/-) embryonic stem (ES) cells. Poly(ADP-ribose) degradation activity was decreased to one-tenth of that in Parg(+/+) ES cells. Parg(-/-) ES cells exhibited the same growth rate as Parg(+/+) ES cells in culture. Sensitivity of Parg(-/-) ES cells to various DNA damaging agents, including an alkylating agent dimethyl sulfate, cisplatin, gemcitabine, 5-fluorouracil, camptothecin, and gamma-irradiation was examined by clonogenic survival assay. Parg(-/-) ES cells showed enhanced lethality after treatment with dimethyl sulfate, cisplatin and gamma-irradiation compared with wild-type (Parg(+/+)) ES cells (p<0.05, respectively). In contrast, a sensitization effect by Parg-deficiency was not observed with gemcitabine and camptothecin. These results suggest the possibility that functional inhibition of Parg leads to sensitization of tumor cells to some chemo- and radiation therapies.
authors.affiliation: Biochemistry Division, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Fujihara
authors.forename: H
authors.initials: H
authors.lastname: Ogino
authors.forename: D
authors.initials: D
authors.lastname: Maeda
authors.forename: H
authors.initials: H
authors.lastname: Shirai
authors.forename: T
authors.initials: T
authors.lastname: Nozaki
authors.forename: N
authors.initials: N
authors.lastname: Kamada
authors.forename: K
authors.initials: K
authors.lastname: Jishage
authors.forename: S
authors.initials: S
authors.lastname: Tanuma
authors.forename: T
authors.initials: T
authors.lastname: Takato
authors.forename: T
authors.initials: T
authors.lastname: Ochiya
authors.forename: T
authors.initials: T
authors.lastname: Sugimura
authors.forename: M
authors.initials: M
authors.lastname: Masutani
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D015152:Blotting, Northern; D015153:Blotting, Western; D002478:Cells, Cultured; D002945:Cisplatin / Q000494:pharmacology; D003114:Colony-Forming Units Assay; D004249:DNA Damage / Q000187:drug effects* / Q000528:radiation effects*; D053595:Embryonic Stem Cells / Q000187:drug effects* / Q000528:radiation effects*; D005720:Gamma Rays; D006026:Glycoside Hydrolases / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013440:Sulfides / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D012333:RNA, Messenger; D013440:Sulfides; D006026:Glycoside Hydrolases; C022407:poly ADP-ribose glycohydrolase; D002945:Cisplatin; C004784:dimethyl sulfide