Edwin V. Gaffney

Human Serum and the Growth of Human Mammary Cells

Human serum from a pool of normal donors, in the presence of fetal bovine serum, inhibited the growth of the major epithelial cell type observed in primary cultures established from biopsy samples of breast carcinoma. In contrast, the growth of cells from nonmalignant mammary tissues removed during reduction mammoplasty and from fibroadenoma was not inhibited. The replication of MCF-7 cells, an established line from a metastatic breast lesion, was also inhibited, whereas the growth of HBL-100 cells, originally derived from a presumably normal source of mammary tissue, was not inhibited by human serum in combination with fetal bovine serum. The growth of two additional cell lines, MDA 157 and MDA 231, was also not affected by human serum. Studies of growth in primary cultures were restricted primarily to direct microscopic observations of the number of cells per colony and the proportion labeled with [3H]thymidine. The results indicate the use of cell lines as adjuncts to primary cultures in future studies of this inhibitory activity.

DNA Content of Mycoplasma-Modified FL Human Amnion Cells

Conclusion Previously reported values for DNA in continuously propagated cell lines, such as KB, HeLa, and FL, were significantly higher than those for normal cells (13). Our data also show an increase in DNA content for two transformed cell lines with malignant characteristics, both derived from normal amnion cells. However, the similarity in DNA content for FL and F 138cl cells indicates that mycoplasma modification, including the change in the malignant state and a reduction of approximately 15% of the chromosome number, cannot be explained by a loss of DNA, but may be interpreted by a rearrangement of the genetic material.

SV40 Transformation of Human Amnion Cells Under Different Culture Conditions

Summary SV40 transformation of primary cultures of human epithelial amnion cells depended on multiplicity of virus exposure, culture age, and medium. Under optimal conditions transformed foci were observed 12 days after infection. Morphological transformation frequency was 10-4. The percentage of cells containing T antigen early after infection was higher than reported for SV40 infected human fibroblasts. Early SV40 production was pronounced and similar virus titers were observed after high and low virus multiplicity within 3 weeks. The amount of growth and the period of time before “crisis” depended on the transfer schedule, but also showed a direct relationship to the original multiplicity of virus exposure.