Human breast carcinoma cell lines: ultrastructural, genotypic, and immunocytochemical characterization.

Two new breast carcinoma cell lines, designated as UISO-BCA-1 and UISO-BCA-2, have been established from pleural effusions of postmenopausal women. Both cell lines show properties of mammary epithelial cells, such as positive immunoreactivity to cytokeratins and human milk fat globulin, presence of desmosomal junctions, numerous microvilli, intracytoplasmic duct-like vacuoles and tonofilaments. UISO-BCA-1 and UISO-BCA-2 cells differ from each other with respect to cellular morphology, ultramicroscopic details, immunoreactivity to Her-neu oncogene protein, chromosomal mode and in vivo and in vitro growth rates. UISO-BCA-1 cells are well-differentiated (as evident from their morphology and ultrastructural details) and hyperploid (42-114 chromosomes). In vitro, UISO-BCA-1 cells are fast growing, with a population doubling time of 31.2 +/- 9.6 hrs (n = 4), and are tumorigenic (100%) in athymic nude mice. In contrast, UISO-BCA-2 cells are poorly differentiated, but are also hyperploid, with 54-64 chromosomes. UISO-BCA-2 cells are slow growing in vitro (population doubling time: 56.0 +/- 5.0 hrs [n = 4]) and have limited tumorigenic potency (20-40%). Both these cell lines are estrogen and progesterone receptor (less than 10 fmol/mg protein) negative.