Establishment of a human carcinoembryonic antigen (CEA)-producing cell line in a protein-free chemically defined medium

Abstract

To examine whether a human carcinoembryonic antigen (CEA)-producing cell can proliferate and sythesize CEA in vitro in culture without protein supplements, long-term cultivation of such cells was carried out in a protein-free chemically defined medium. Using stepwise decreases in fetal bovine serum concentration, continuous growth of the cells was established in a protein-free am's F-12 medium. The cells, designated as HLC-Yl, have been propagated in this medium for 3 years. The population doubling time of the cells is about 52 h. Addition of the serum stimulated the cell growth (population doubling time = 27 h). Saturation density was not increased by the addition of serum. The cells grown in a protein-free F-12 secrete large amounts of CEA (65.4 +/- 2.6 ng/10(6) cells/24 h). Addition of serum did not stimulate the production of CEA. The cells produced tumours when inoculated into athymic nude mice. The mice bearing the tumour showed high serum CEA levels, and CEA was demonstrated in the tumour tissue by the immunoperoxidase method. The present study suggests that cells grown in a protein-free medium do not require serum components for their growth or CEA synthesis and provide an excellent model for better understanding the growth and production of CEA in human lung cancer cells.

A new assay system for quality control testing of a chemically defined medium

“…To detect significant deviations from the designated formula, the presence of chemical contaminants, or a negative influence of storage conditions the use of sensitive cell lines grown in serum-free media has been suggested 19,10). To achieve sustained cell growth, however, such media usually have to be supplemented with various protein growth factors and hormones (1,2) that possibly prevent the effect of contaminants.Several cell lines, including mouse NCTC clone 929 L {L-929) cells, have been established in chemically defined media without any protein supplement (3,6,7,(12)(13)(14)20,22,23). The present study shows that L-929 cells grown continuously in such a medium can be used as a highly sensitive and simple cell culture system for quality control testing.…”