Evaluation of ionizing radiation sensitivity markers in a panel of lymphoid cell lines.
OBJECTIVE
To examine the possible associations between radiation sensitivity to doses 2 Gy, and such features of lymphoid cell responses as apoptosis, expression of apoptosis regulatory proteins (Bcl-2 family) and cell cycle progression in relation to biological dosimetry.


METHODS
The cell lines examined were: Epstein Barr virus transformed lymphoid ataxia-telangiectasia (AT) cell lines, GM00717C, homozygous, and GM00736A, heterozygous, for ATM; human pro-B lymphoblastic leukaemia, Reh; murine L5178Y lymphoma sublines, LY-R and LY-S. Assays performed following X-irradiation with doses from 0.1 to 2 Gy were: terminal deoxyribonucleotidyl transferase (TdT) assay to measure apoptotic fraction, DNA content analysis by flow cytometry to assess cell cycle distribution, trypan blue exclusion test to determine cell viability, cytochalasin block micronucleus assay to assess cytogenetic damage, and Western blotting to detect proteins from the Bcl-2 family.


RESULTS
The cell lines in the study were of different but rather high radiation sensitivity, which was unrelated to their propensity to undergo apoptosis or micronucleus frequency. The expression of apoptotic regulatory proteins from the Bcl-2 family (constitutive and expressed 4 or 24 h after irradiation) was not related to radiation sensitivity.


CONCLUSIONS
None of the simple predictive tests used in the study, alone or evaluated together was suitable for detection of radiation hypersensitivity although cells known to be hypersensitive (LY-S and GM00717C) were included in the analysis.
Department of Radiation Medicine, Norwegian Radiation Protection Authority, Oesteraas, Norway.
A
A
Jaworska
I
I
Szumiel
P
P
De Angelis
G
G
Olsen
J
J
Reitan
D000818:Animals; D017209:Apoptosis; D015415:Biomarkers; D002452:Cell Count; D002453:Cell Cycle / Q000528:radiation effects; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D004247:DNA / Q000032:analysis / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005434:Flow Cytometry; D006801:Humans; D020287:In Situ Nick-End Labeling; D008214:Lymphocytes / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D051379:Mice; D015162:Micronucleus Tests; D011237:Predictive Value of Tests; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011836:Radiation Tolerance
D015415:Biomarkers; D019253:Proto-Oncogene Proteins c-bcl-2; D004247:DNA