Flow cytometric and morphological studies of ovarian carcinoma cell lines and xenografts

Human ovarian cancers of four different histological types have been cultured in vitro and in nude mice. Nineteen tumor specimens (11 solid tumors and eight malignant effusions) were obtained from 14 patients. Tumor lines from ten of these patients were established after several subpassages, and six xenograft lines have been grown, all of them from tumors of which a cell line exists in vitro. In all, 14 lines have been successfully cultured from the 19 tumor specimens. The morphology (studied by light and electron microscopy) of the established lines in vitro and in vivo resembles that of the original tumors in all cases. Flow cytometric studies of DNA content of the original tumor specimens and the cell culture and xenograft lines were performed. In all lines in both culture systems, aneuploid cells became predominant after the first to fourth passages, despite an aneuploid peak having been evident in only nine of the 19 initial specimens. Four of the original tumor specimens contained measurable estrogen receptors and five progesterone receptors, but none of the established cell lines expressed these hormone receptors. These results indicate that, while morphological features are similar in the initial tumor specimens and in the established lines in vitro and in vivo, flow cytometric and steroid hormone receptor data suggest selection of aneuploid and receptor-negative cells.