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Record Details

Record 18 of 1286
Distribution of Chromosome Breakpoints in Human Epithelial Cells Exposed to Low- and High-LET Radiations
Author and Affiliation:
Hada, Megumi(NASA Johnson Space Center, Houston, TX, United States)
Cucinotta, Francis(NASA Johnson Space Center, Houston, TX, United States)
Wu, Honglu(NASA Johnson Space Center, Houston, TX, United States)
Abstract: The advantage of the multicolor banding in situ hybridization (mBAND) technique is not only its ability to identify simultaneously both inter- and intrachromosome exchanges, but also the ability to measure the breakpoint location along the length of the chromosome in a precision that is unmatched with other traditional banding techniques. Breakpoints on specific regions of a chromosome have been known to associate with specific cancers. The breakpoint distribution in cells after low- and high-LET radiation exposures will also provide the data for biophysical modeling of the chromatin structure, as well as the data for the modeling the formation of radiation-induced chromosome aberrations. In a series of experiments, we studied low- and high-LET radiation-induced chromosome aberrations using the mBAND technique with chromosome 3 painted in 23 different colored bands. Human epithelial cells (CH1 84B5F5/M10) were exposed in vitro to Cs- 137 rays at both low and high dose rates, secondary neutrons with a broad energy spectrum at a low dose rate and 600 MeV/u Fe ions at a high dose rate. The data of both inter- and intrachromosome aberrations involving the painted chromosome have been reported previously. Here we present data of the location of the chromosome breaks along the length of chromosome 3 in the cells after exposures to each of the four radiation scenarios. In comparison to the expected breakpoint distribution based on the length of the bands, the observed distribution appeared to be non-random for both the low- and high-LET radiations. In particular, hot spots towards both ends of the chromosome were found after low-LET irradiations of either low or high dose rates. For both high-LET radiation types (Fe ions and neutrons), the breakpoint distributions were similar, and were much smoother than that for low-LET radiation. The dependence of the breakpoint distribution on the radiation quality requires further investigations.
Publication Date: Jan 01, 2009
Document ID:
20090042484
(Acquired Dec 11, 2009)
Subject Category: LIFE SCIENCES (GENERAL)
Report/Patent Number: JSC-CN-19438
Document Type: Conference Paper
Meeting Information: NASA Human Research Program Investigators' Workshop; 3-5 Feb. 2010; Houston, TX; United States
Financial Sponsor: NASA Johnson Space Center; Houston, TX, United States
Organization Source: NASA Johnson Space Center; Houston, TX, United States
Description: 1p; In English; Original contains black and white illustrations
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: IN VITRO METHODS AND TESTS; CHROMOSOME ABERRATIONS; RADIATION DOSAGE; RANGE (EXTREMES); BIOPHYSICS; EXPOSURE; PROTEINS; CHROMATIN; IRRADIATION; POSITION (LOCATION); SPECTRA
Availability Source: Other Sources
Availability Notes: Abstract Only
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