@entity5 induction by space radiations is a major concern for manned space exploration. Accurate assessment of radiation risk at low doses requires basic understanding of mechanism(s) of @entity105 . For determining the oncogenic effects of ionizing radiation in @entity1 epithelial cells, we transformed a mammary epithelial cell line (185B5), which was immortalized by @entity3014 , with energetic heavy ions and obtained several transformed clones. These transformed cells showed growth properties on Matrigel similar to @entity1 @entity5 cells. To better understand the mechanisms of radiogenic transformation of @entity1 cells, we systematically examined the alterations in chromosomes and @entity5 genes. Among 16 autosomes examined for translocations, by using fluorescence in situ hybridization (FISH) technique, chromosomes 3, 12, 13, 15, 16, and 18 appeared to be normal in transformed cells. Chromosomes 1, 4, 6, 8, and 17 in transformed cells, however, showed patterns different from those in nontransformed cells. Southern blot analyses indicated no detectable alterations in myc, ras, Rb, or @entity876 genes. Further studies of chromosome 17 by using in situ hybridization with unique sequence @entity876 gene probe and a centromere probe showed no loss of @entity876 gene in transformed cells. Experimental results from cell fusion studies indicated that the transforming gene(s) is recessive. The role of genomic instability and @entity5 suppressor gene(s) in radiogenic transformation of @entity1 breast cells remains to be identified.

Radiogenic transformation of XXXX mammary epithelial cells in vitro.

@entity1 :: ('9606', 'Species') :: ['human'] @entity5 :: ('MESH:D009369', 'Disease') :: ['tumor', 'cancer', 'mammary tumor', 'Cancer'] @entity3014 :: ('MESH:D001564', 'Chemical') :: ['benzo(a)pyrene'] @entity876 :: ('7157', 'Gene') :: ['p53'] @entity105 :: ('MESH:D063646', 'Disease') :: ['radiation carcinogenesis']
@entity1 :: (9606,Species) :: ['human']
