Document Detail

Explaining differences in sensitivity to killing by ionizing radiation between human lymphoid cell lines.
MedLine Citation:
PMID:  9661896     Owner:  NLM     Status:  MEDLINE    
We surveyed five human hematopoietic cell lines (HSB-2, MOLT-4, Reh, CEM, and HL-60) to determine whether any simple correlates with sensitivity to killing by gamma-irradiation might be revealed. The clonogenic survival gamma-ray dose-response curves for these cell lines cover a wide range of sensitivities. Consistent with previous results for murine hematopoietic cell lines, there was a clear correlation between the rapidity with which irradiation induced apoptosis and clonogenic radiosensitivity of a cell line, although the relationship between timing of apoptosis and radiosensitivity differed between human and murine cell lines. Flow cytometric determination of cell cycle distribution after irradiation showed that differences between human hematopoietic cell lines, in the rate of induction of apoptosis, were generally related to the functioning of cell cycle checkpoints. Whereas the rapidly dying and radiosensitive HSB-2 cell line underwent apoptosis from different points in the cell cycle, the more slowly dying cell lines showed a variety of cell cycle arrest profiles and initiated apoptosis after accumulation of cells in the G2 phase. The lag-phase between arrest in G2 and induction of apoptosis was comparable for MOLT-4, Reh, and CEM; however, HL-60 cells showed a markedly longer G2 arrest that correlated with their greater radioresistance. The results suggest that the total length of time available for DNA damage repair (irrespective of whether this time accrues as blockage in G1, S, or G2), prior to potential activation of apoptosis, is a critical determinant of radiosensitivity in human hematopoietic cell lines. Comparison of the p53 status of these cell lines suggested that mutations in the TP53 gene are contributing to the delay of induction of apoptosis seen in the more radioresistant cell lines. The sensitivity of MOLT-4 and HL-60 cells to killing by DNA-associated 125I decays was determined and was found to correlate with the relative sensitivity of these lines to gamma-irradiation. The highly localized deposition of energy by 125I decays argues that DNA damage is a potent initiator of apoptosis in these cell lines. The results presented suggest that differences in the radiosensitivity of the cell lines examined reflect differences in the rapidity of induction of apoptosis and that radiation-induced cell death in hematopoietic cells can be explained as a response to DNA damage.
D R Aldridge; I R Radford
Related Documents :
20577596 - Cotylenin a inhibits cell proliferation and induces apoptosis and pax6 mrna transcripts...
12528126 - Serum amyloid p component binds to late apoptotic cells and mediates their uptake by mo...
12689596 - Annexin i is an endogenous ligand that mediates apoptotic cell engulfment.
15199606 - In vitro proliferation of fibrosarcoma cells depends on intact functions of lipoxygenas...
20809546 - Conservation of the chromatophore pigment response.
1408476 - Antioxidant defense mechanisms of endothelial cells and renal tubular epithelial cells ...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Cancer research     Volume:  58     ISSN:  0008-5472     ISO Abbreviation:  Cancer Res.     Publication Date:  1998 Jul 
Date Detail:
Created Date:  1998-07-23     Completed Date:  1998-07-23     Revised Date:  2005-11-17    
Medline Journal Info:
Nlm Unique ID:  2984705R     Medline TA:  Cancer Res     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2817-24     Citation Subset:  IM    
Sir Donald and Lady Trescowthick Research Laboratories, Peter MacCallum Cancer Institute, East Melbourne, Victoria, Australia.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Apoptosis / radiation effects*
Cell Cycle / physiology,  radiation effects*
Cell Survival / radiation effects
DNA Damage*
DNA Repair
Dose-Response Relationship, Radiation
G2 Phase / physiology,  radiation effects
Gamma Rays*
HL-60 Cells / radiation effects
Iodine Radioisotopes / metabolism
Proto-Oncogene Proteins c-bcl-2 / metabolism
Radiation Tolerance
Time Factors
Tumor Cells, Cultured / radiation effects
Tumor Suppressor Protein p53 / metabolism
Reg. No./Substance:
0/Iodine Radioisotopes; 0/Proto-Oncogene Proteins c-bcl-2; 0/Tumor Suppressor Protein p53

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Sensitivity of K562 and HL-60 cells to edelfosine, an ether lipid drug, correlates with production o...
Next Document:  Recombinant humanized anti-HER2 antibody (Herceptin) enhances the antitumor activity of paclitaxel a...