Relationship between changes in ploidy and stable cellular resistance to hydrogen peroxide

摘要: Stable hydrogen peroxide (H2O2)-resistant variants of the Chinese hamster ovary HA-1 line have been isolated by culturing cells in progressively increasing concentrations H2O2 (greater than 200 days, 50-800 microM H2O2). Increases catalase activity these variant cell lines were shown to correlate with increased resistance. 240 days) H2O2-resistant lines, seven quasidiploid (21-22 chromosomes/cell) and six quasitetraploid (40-44 clonally from 800 adapted which heterogeneous respect ploidy. The dose-modifying factors (DMFs) 3, 5, 8, 13, 15, 26, 27 for 21, 32, 38, 40, 42, 49 lines. mean DMF was 14 +/- 10 former 37 latter. Our data show that on average significantly more resistant H2O2-mediated killing derived same mixed population H2O2-adapted cells. When activities (k units/cell) three (two one quasitetraploid) determined plotted vs. H2O2-DMF, a positive linear correlation obtained (correlation coefficient = 0.99). This result further confirmed when immunoreactive protein/cell detected Western blots. chronic exposure stress (800 microM) accompanied increases within population. Quasitetraploid this demonstrated stable H2O2-resistance may be related expression catalase.