Cytological characterization of repair-deficient CHO cell line 43-3B. I. Induction of chromosomal aberrations and sister-chromatid exchanges by UV and its modulation with 3-aminobenzamide.
The induction of chromosomal aberrations and sister-chromatid exchanges (SCEs) by short-wave ultraviolet (UV) and X-irradiation was studied in Chinese hamster ovary (CHO) wild-type (WT) cells and one of its UV-hypersensitive mutants, 43-3B. The results indicate that CHO 43-3B show high levels of spontaneously occurring chromosomal aberrations and SCEs; these levels are, respectively, approximately 4 and 1.7 times those found in WT CHO. Treatment with UV produced a considerable delay in the cell-cycle progression of the mutant cells compared to the WT cells. Doses of UV that had no effect on WT cells, significantly induced chromosomal alterations in the mutant in a dose-dependent manner. An approximately 5-fold increase in the induced frequencies of SCEs was obtained in 43-3B cells after UV treatment. No synergistic effect was observed with UV irradiation and the inhibitor of poly(ADP-ribose) synthetase, 3-aminobenzamide (3AB), in either cell type. The frequency of SCEs in the mutant cell lines was lower than would be expected if the effects of UV and the inhibitor were additive. X-Ray alone in G1 and in combination with 3AB in G2 did not induce increased frequencies of chromosomal aberrations in mutant cells in comparison to the WT cells.
D000818:Animals; D001549:Benzamides / Q000633:toxicity; D002453:Cell Cycle; D002460:Cell Line; D002869:Chromosome Aberrations; D006224:Cricetinae; D003412:Cricetulus; D004260:DNA Repair / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005260:Female; D010053:Ovary; D012854:Sister Chromatid Exchange / Q000187:drug effects / Q000528:radiation effects; D014466:Ultraviolet Rays; D014965:X-Rays
D001549:Benzamides; C025160:3-aminobenzamide