title: Comparison of spontaneous mutagenesis in early-passage human mammary cells from normal and malignant tissues.
abstract: Spontaneous mutant frequencies were determined in early-passage epithelial-cell strains derived from either normal or malignant human breast tissues, as well as a non-tumorigenic immortalized human mammary epithelial cell line (184B5) derived from normal cells. Mutations at the hypoxanthine-guanine phophoribosyltransferase (HPRT) locus were quantified by determining the 6-thioguanine resistance. Mutant frequencies in human mammary epithelial cells (HMEC) from 4 normal and 5 carcinoma tissue samples did not differ significantly. In contrast, the mutant frequency in the immortalized HMEC was approximately 10 times higher than in average normal HMEC and normal non-immortalized cells from early-passage cultures of the same cell lineage. Our data suggest that the progression of normal breast cells to invasive carcinoma cells does not necessarily involve the establishment of a general genetic instability during this progression.
authors.affiliation: Department of Human Oncology, University of Wisconsin Clinical Cancer Center, Madison 53792.
authors.forename: S R
authors.initials: SR
authors.lastname: Eldridge
authors.forename: M N
authors.initials: MN
authors.lastname: Gould
mesh_terms: D001940:Breast / Q000166:cytology / Q000201:enzymology / Q000502:physiology*; D001943:Breast Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D002478:Cells, Cultured; D004847:Epithelial Cells; D005260:Female; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D016296:Mutagenesis / Q000235:genetics / Q000502:physiology*; D014407:Tumor Cells, Cultured
chemical_list: D007041:Hypoxanthine Phosphoribosyltransferase