title: Initiation of oncogenic transformation in human mammary epithelial cells by charged particles.
abstract: Experimental studies have shown that high linear-energy transfer (LET) charged particles can be more effective than x-rays and gamma-rays in inducing oncogenic transformation in cultured cells and tumors in animals. Based on these results, experiments were designed and performed with an immortal human mammary epithelial cell line (H184B5), and several clones transformed by heavy ions were obtained. Cell fusion experiments were subsequently done, and results indicate that the transforming gene(s) is recessive. Chromosome analysis with fluorescence in situ hybridization (FISH) techniques also showed additional translocations in transformed human mammary epithelial cells. In addition, studies with these cell lines indicate that heavy ions can effectively induce deletion, break, and dicentrics. Deletion of tumor suppressor gene(s) and/or formation of translocation through DNA double strand breaks is a likely mechanism for the initiation of oncogenic transformation in human mammary epithelial cells.
authors.affiliation: Radiation Biophysics Laboratory, NASA Johnson Space Center, Houston, Texas 77058, USA. tyang@plato.jsc.nasa.gov
authors.forename: T C
authors.initials: TC
authors.lastname: Yang
authors.forename: K A
authors.initials: KA
authors.lastname: Georgy
authors.forename: L M
authors.initials: LM
authors.lastname: Craise
authors.forename: M
authors.initials: M
authors.lastname: Durante
mesh_terms: D001940:Breast / Q000473:pathology / Q000528:radiation effects*; D002459:Cell Fusion; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000473:pathology / Q000528:radiation effects*; D002478:Cells, Cultured; D019457:Chromosome Breakage; D002872:Chromosome Deletion; D002875:Chromosomes / Q000737:chemistry / Q000235:genetics; D004247:DNA / Q000235:genetics / Q000528:radiation effects; D004249:DNA Damage; D004848:Epithelium / Q000473:pathology / Q000528:radiation effects; D005260:Female; D005720:Gamma Rays; D017353:Gene Deletion; D005808:Genes, Recessive / Q000235:genetics; D016147:Genes, Tumor Suppressor / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D018499:Linear Energy Transfer; D009381:Neoplasms, Radiation-Induced / Q000209:etiology; D011839:Radiation, Ionizing; D014170:Transformation, Genetic / Q000235:genetics; D014178:Translocation, Genetic / Q000235:genetics; D014965:X-Rays
chemical_list: D004247:DNA