DNA Copy-Number Instability in Low-Dose Gamma-Irradiated TK6 Lymphoblastoid Clones

• DOI: 10.1667/rr1096.1
• Publication Date: 2008-02-26T21:16:52Z
• Authors: Robert R. Kimmel; Shivali Agnani; Yin Yang; Robert Jordan; Jeffrey L. Schwartz
• Keywords: Lymphoblast; Gamma Irradiation

Kimmel, R. R., Agnani, S., Yang, Y., Jordan, and Schwartz, J. L. DNA Copy-Number Instability in Low-Dose Gamma-Irradiated TK6 Lymphoblastoid Clones. Radiat. Res. 169, 259–269 (2008).Genomic instability that might occur early during low-dose, fractionated radiation exposures may be traceable radiogenic compared to spontaneous cancers. Using a human 18K cDNA microarray-based comparative genome hybridization protocol, we measured changes copy number at over 14,000 loci nine low-dose 137Cs γ-irradiated (acute exposure 10 cGy/day × 21 days) unirradiated clones estimated locus-specific copy-number differences between them. Radiation induced hypervariability thousands of across all chromosomes, with sevenfold increase low-level, randomly positioned gains. Recurrent gains 40 occurred among irradiated were distributed nonrandomly the genome, highest densities 3q, 13q 20q sites hypodiploid without irradiation. Another set 94 exhibited relative recurrent from state diploid state, suggesting hemizygous-to-homozygous transitions. Frequently recurring losses 57 concentrated on single X-chromosome but sparsely 0–2 per autosome. These results suggest mitotic homologous recombination as possible mechanism radiation-induced genomic instability. Genomic cells resembled seen tumors suggests way could induce preneoplastic cells.