Correlation between cell reproductive death and chromosome aberrations assessed by FISH for low and high doses of radiation and sensitization by iodo-deoxyuridine in human SW-1573 cells.
OBJECTIVE
To study the relationship between cell reproductive death and exchange frequency in SW-1573 human lung tumour cells with and without incorporated iodo-deoxyuridine (IdUrd) following irradiation of plateau-phase cultures with y-rays.


METHODS
Linear-quadratic (LQ) analysis was performed for the data on clonogenic survival and on the frequency of chromosomal exchanges studied with fluorescence in situ hybridization in chromosomes X and 2.


RESULTS
Differences in the LQ parameters alpha and beta of both non-sensitized and sensitized chromosomes were found. In both chromosomes an increase in the number of chromosomal exchanges in IdUrd-radiosensitized cells compared with non-sensitized cells was observed. The alpha-enhancement factors of 1.7 and 1.9 for the X-chromosome and for chromosome 2, respectively, are similar. For the X-chromosome, the beta coefficient increased by a factor of 3.9 and for chromosome 2 by a factor of 1.4. After correction to a full genome equivalence, no significant difference in alpha was found between chromosomes X and 2 for both control and sensitized cells. In contrast, an almost 2.8 times higher beta was found for the sensitized X-chromosome compared to this value for chromosome 2.


CONCLUSIONS
It can be concluded that the linear-quadratic analysis of dose-response relationships offers insights into the correlation between cell survival and induction of exchanges in non-sensitized and radiosensitized cells.
Franken
N A
NA
Department of Radiotherapy, Academic Medical Centre, University of Amsterdam, The Netherlands. N.A.Franken@AMC.UVA.NL
Ruurs
P
P
Ludwików
G
G
van Bree
C
C
Kipp
J B
JB
Darroudi
F
F
Barendsen
G W
GW
D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000532:radiotherapy / Q000648:ultrastructure; D016923:Cell Death / Q000528:radiation effects; D002455:Cell Division / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002869:Chromosome Aberrations; D002889:Chromosomes, Human, Pair 2 / Q000528:radiation effects*; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007065:Idoxuridine / Q000378:metabolism / Q000494:pharmacology*; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000473:pathology* / Q000532:radiotherapy / Q000648:ultrastructure; D019384:Nucleic Acid Synthesis Inhibitors / Q000378:metabolism / Q000494:pharmacology*; D011838:Radiation-Sensitizing Agents / Q000378:metabolism / Q000494:pharmacology*; D013936:Thymidine / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000528:radiation effects; D014960:X Chromosome / Q000528:radiation effects*
D019384:Nucleic Acid Synthesis Inhibitors; D011838:Radiation-Sensitizing Agents; D007065:Idoxuridine; D013936:Thymidine