Poly(ADP-ribose) Glycohydrolase deficiency sensitizes mouse ES cells to DNA damaging agents.
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.
Fujihara
H
H
Biochemistry Division, National Cancer Center Research Institute, Chuo-ku, Tokyo 104-0045, Japan.
Ogino
H
H
Maeda
D
D
Shirai
H
H
Nozaki
T
T
Kamada
N
N
Jishage
K
K
Tanuma
S
S
Takato
T
T
Ochiya
T
T
Sugimura
T
T
Masutani
M
M
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
D000970:Antineoplastic Agents; D012333:RNA, Messenger; D013440:Sulfides; D006026:Glycoside Hydrolases; C022407:poly ADP-ribose glycohydrolase; D002945:Cisplatin; C004784:dimethyl sulfide