Project description:Breast cancer ranks top in the incidence among the main sites of female cancer in Japan. The epidemiological study on atomic bomb survivors has suggested that the excess relative risk for breast cancer is higher than any other sites. Little is known, however, about the molecular mechanisms of breast cancer induction by radiation. Therefore, we analyzed here the genome-wide copy number aberration of radiation-induced rat mammary carcinomas using microarray-based comparative genomic hybridization (array-CGH). Mammary carcinomas were induced by 2 Gy gamma irradiation of Sprague-Dawley (SD) rats at 3 or 7 weeks of age. We examined 14 mammary carcinomas induced by gamma-irradiation (2 Gy) and found 26 aberrations including trisomies of chromosomes 4 and 10 in 3 and 1 carcinomas, respectively, and deletion of chromosomes 3q35q36 and 5q32 (Cdkn2a and Cdkn2b region) in 2 and 2 carcinomas, respectively. On the other hand, only one aberration (amplification of chromosome 10q31) was observed in four spontaneous mammary carcinomas. These results suggest that the trisomy of chromosome 4 and deletion of chromosomes 3q35q36 and 5q32 were associated with radiation exposure.

2010-08-09 | GSE16128 | GEO