Elevated G2 chromosomal radiosensitivity in Irish breast cancer patients: a comparison with other studies

作者：Orla Howe, PA Daly, Colin Seymour, W. Ormiston, C. Nolan, Carmel Mothersill · 发表于：International Journal of Radiation Biology · 年份：2005 · DOI：10.1080/09553000500147642 · 被引用次数：34 · 研究领域：DNA Repair Mechanisms、Carcinogens and Genotoxicity Assessment、BRCA gene mutations in cancer

Previous studies have shown that a significant proportion of breast cancer patients exhibit elevated G2 chromosomal radiosensitivity in contrast to controls (approximately 40%). In this study, the G2 assay was applied to a small number of Irish breast cancer patients who were recorded as sporadic cases and they were compared with a control group to compare and contrast with the previous documented studies. Lymphocyte cultures were set up on whole blood samples and stimulated with phytohaemagglutinin. The cultures were irradiated 74 h later with 0.5 Gy gamma-radiation and cells were arrested in metaphase by treating the cultures with colcemid. The chromosomes were harvested and the aberrations scored per 100 metaphases to assign a G2 score. The assay was first carried out on four donor controls to estimate intra-individual variation and then ten controls for inter-individual variation to measure assay reproducibility. The G2 assay was then applied to 27 breast cancer patients. Good intrinsic assay reproducibility was observed in the coefficient of variation (CV) data in three out of four controls. Intra-individual variation was similar in three out of four of the donors (4.6 - 5.1%) with one donor showing a higher CV compared with the others (22.9%). Inter-individual variation was calculated at 30.5% for all controls. No significant difference was observed between intra- and inter-individual variation using the variance ratio F-test. A G2 radiosensitivity cut-off of 110 aberra...