RESPONSE OF RADIATION-SENSITIVE HUMAN-CELLS TO DEFINED DNA BREAKS

COSTA ND THACKER J

Nd. Costa et J. Thacker, RESPONSE OF RADIATION-SENSITIVE HUMAN-CELLS TO DEFINED DNA BREAKS, International journal of radiation biology, 64(5), 1993, pp. 523-529

39

INGLESE

Article

Radiology,Nuclear Medicine & Medical Imaging","Nuclear Sciences & Tecnology

International journal of radiation biology → ACNP

0955-3002

64

5

1993

523 - 529

ISI

0955-3002(1993)64:5<523:RORHTD>2.0.ZU;2-8

We have investigated the response of four human cell lines, representi ng a range of sensitivities to ionizing radiation, to enzymes which in duce defined DNA double-strand breaks (dsbs). Cell lines were derived from a normal individual, from the cancer-prone disorders ataxia-telan giectasia (AT) and Bloom's syndrome (BS), and from an immunodeficient individual (46BR). The molecular defects in AT and BS are unknown, whi le 46BR is known to be DNA ligase I deficient. We assayed the clonogen ic survival of the cell lines following in vivo scission of the DNA by the restriction endonucleases PvuII and BanI. These two enzymes diffe r in their action; PvuII gives rise to dsbs with blunt termini, while BanI generates staggered ends with a 4 bp overhang. We found a correla tion between the sensitivity of the cell lines to X-rays and to the bl unt-end cutter PvuII, but not to the cohesive-end cutter BanI.