USE OF FLUORESCENCE IN-SITU HYBRIDIZATION (FISH) TO STUDY CHROMOSOMALDAMAGE-INDUCED BY RADIATION AND BROMODEOXYURIDINE IN HUMAN COLON-CANCER CELLS

Citation
Sr. Wilt et al., USE OF FLUORESCENCE IN-SITU HYBRIDIZATION (FISH) TO STUDY CHROMOSOMALDAMAGE-INDUCED BY RADIATION AND BROMODEOXYURIDINE IN HUMAN COLON-CANCER CELLS, International journal of radiation oncology, biology, physics, 30(4), 1994, pp. 861-866
Citations number
20
Categorie Soggetti
Oncology,"Radiology,Nuclear Medicine & Medical Imaging
ISSN journal
03603016
Volume
30
Issue
4
Year of publication
1994
Pages
861 - 866
Database
ISI
SICI code
0360-3016(1994)30:4<861:UOFIH(>2.0.ZU;2-H
Abstract
Purpose: Although the thymidine analog radiation sensitizer bromodeoxy uridine (BrdUrd) increases radiation-induced chromosomal aberrations, it is not known whether these aberrations are uniformly distributed am ong chromosomes. Using fluorescence in situ hybridization, we carried out a study to test the hypothesis that BrdUrd-induced radiosensitizat ion may be mediated by nonuniform chromosomal damage. Methods and Mate rials: Log phase HT29 human colon cancer cells were exposed to 10 mu M BrdUrd (or media alone) for one cell cycle, and the G1 cells were sep arated by centrifugal elutriation. Half of the control and BrdUrd samp les were irradiated with 8 Gy. Cells were then incubated for 24-28 h, and metaphase spreads were prepared. Fluorescence in situ hybridizatio n was performed using paint probes for chromosomes 1 and 4. Results: W e found that radiation induced 0.20 aberrations per chromosome in chro mosome 4. Based on the ratio of the relative lengths of chromosome 1-4 (1.34), it was predicted that chromosome 1 would have approximate to 0.26 aberrations per chromosome. However, me observed 0.39 aberrations per chromosome 1, which was significantly greater than the predicted (p < 0.001 by chi-square). Incubation with BrdUrd prior to irradiation significantly increased the aberrations found in chromosome 1 (by a f actor of 1.4) and chromosome 4 (by a factor of 1.9) compared to radiat ion alone (p < 0.001 for both chromosome 1 and 4). Conclusion: This st udy demonstrates that individual chromosomes in human colon cancer cel ls show significantly different rates of aberration after irradiation. Furthermore, the BrdUrd-mediated increase in radiation-induced chromo somal aberrations may not be uniform among chromosomes.