Apoptosis induced by X-rays and chemical agents in murine fibroblastic cell lines with a defect in repair of DNA double-strand breaks.
OBJECTIVE
To investigate apoptosis in murine fibroblasts that are deficient in DNA double-stand breaks (dsb) repair.


METHODS
BALB/c 3T3 cells and cells from a severe combined immunodeficient (scid) mouse were exposed to X-rays, UV light, bleomycin, etoposide or cisplatin. After exposure, the rate of apoptosis was assayed by propidium iodide staining based on characteristic morphological change.


RESULTS
The scid cells, defective in dsb repair, were extremely sensitive to apoptosis induced by X-rays and bleomycin compared with BALB/c 3T3 cells. The scid cells were slightly sensitive to apoptosis induced by etoposide, an agent producing protein-associated dsb, and to apoptosis induced by agents not causing dsb.


CONCLUSIONS
These studies show that sensitivity of cells to apoptosis induced by X-rays or bleomycin is enhanced by the scid mutation and that apoptosis induced by etoposide, which causes protein-associated dsb, is not greatly affected. There may be different processes involved in the induction of apoptosis by X-rays or bleomycin and etoposide.
Meng
H
H
Department of Experimental Radiology, Shiga University of Medical Science, Otsu, Japan.
Terado
T
T
Kimura
H
H
D016475:3T3 Cells / Q000166:cytology / Q000378:metabolism; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects*; D001761:Bleomycin / Q000494:pharmacology; D002945:Cisplatin / Q000494:pharmacology; D004247:DNA / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D005047:Etoposide / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D009687:Nuclear Proteins; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology; D012680:Sensitivity and Specificity; D014466:Ultraviolet Rays; D014965:X-Rays
D000964:Antimetabolites, Antineoplastic; D000972:Antineoplastic Agents, Phytogenic; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011838:Radiation-Sensitizing Agents; D001761:Bleomycin; D005047:Etoposide; D004247:DNA; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human; D017346:Protein Serine-Threonine Kinases; D002945:Cisplatin