caa a22 4500 465820301 CHVBK 20180323112134.0 cr unu---uuuuu 170327e19900101xx s 000 0 eng 10.1007/BF01650478 doi (NATIONALLICENCE)springer-10.1007/BF01650478 Some ras -transformed cells have increased radiosensitivity and decreased repair of sublethal radiation damage [Elektronische Daten] [John Harris, Ann Chambers, Andrew Tam] We examined the effect of60Co irradiation on the clonogenic survival of rat NRK cells, NRK cells carrying a temperature-sensitive viralK-ras oncogene (tsK-NRK), mouse NIH 3T3 cells, and NIH 3T3 cells transformed with the human bladder cancer (T24)H-ras oncogene (PAP2). We tested the hypothesis thatras oncogene expression renders cells more resistant to radiation, but found in both systems thatras-transformed cells were more, not less, sensitive to radiation. We also found indications of altered repair of sublethal radiation damage. PAP2 cells were more sensitive to radiation than NIH 3T3 cells. Increased sensitivity was reflected in a decreased shoulder region of the survival curve with little effect on its slope (D 0). TsK-NRK cells were also slightly more sensitive to radiation than NRK and exhibited decreased repair of sublethal damage at both the permissive and nonpermissive temperatures. Thus, we found that expression ofras oncogenes is not always associated with increased radiation resistance. In summary, our results suggest that (1)ras oncogene expression in some cells may be associated with increased, rather than decreased, radiation sensitivity, and (2)ras oncogene expression may alter the shoulder region of the does response curve, suggesting changes in the repair of sublethal radiation damage. Plenum Publishing Corporation, 1990 Harris John London Regional Cancer Centre, 790 Commissioners Road East, N6A 4L6, London, Ontario, Canada aut Chambers Ann London Regional Cancer Centre, 790 Commissioners Road East, N6A 4L6, London, Ontario, Canada aut Tam Andrew London Regional Cancer Centre, 790 Commissioners Road East, N6A 4L6, London, Ontario, Canada aut Somatic Cell and Molecular Genetics Kluwer Academic Publishers-Plenum Publishers 16/1(1990-01-01), 39-48 0740-7750 16:1<39 1990 16 11188 https://doi.org/10.1007/BF01650478 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01650478 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Harris John London Regional Cancer Centre, 790 Commissioners Road East, N6A 4L6, London, Ontario, Canada aut NATIONALLICENCE 700 1- Chambers Ann London Regional Cancer Centre, 790 Commissioners Road East, N6A 4L6, London, Ontario, Canada aut NATIONALLICENCE 700 1- Tam Andrew London Regional Cancer Centre, 790 Commissioners Road East, N6A 4L6, London, Ontario, Canada aut NATIONALLICENCE 773 0- Somatic Cell and Molecular Genetics Kluwer Academic Publishers-Plenum Publishers 16/1(1990-01-01), 39-48 0740-7750 16:1<39 1990 16 11188 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer