Plasma protein and apolipoprotein synthesis by human yolk sac carcinoma cells in vitro.
Three human yolk sac carcinoma cell lines were characterized for the expression of several markers. Each of the cell lines expressed alpha-fetoprotein, without detectable levels of chorionic gonadotropin, and the level of alpha-fetoprotein expression increased dramatically when the cultures were held without passage for extended periods. The secretion of a number of plasma proteins was documented by metabolic labeling, immunoprecipitation, and gel analysis. The major plasma proteins detected were alpha-1-antitrypsin, alpha-fetoprotein, transthyretin, beta-2 microglobulin, and plasminogen, with lower levels of transferrin and complement C4 released. Apolipoproteins B, E, and A1 were secreted in high levels as well and were found in the form of lipoprotein particles. Time course experiments on the synthesis of apolipoproteins E and A1 indicated that, as with alpha-fetoprotein, the level of synthesis increased substantially when the cultures were held without passage. The results indicate that these yolk sac carcinoma cells display a protein expression profile similar to that observed for the human yolk sac, and the possibility that the cells may have the potential to differentiate is discussed.
Lanford
R E
RE
Department of Virology and Immunology, Southwest Foundation for Biomedical Research, San Antonio, Texas 78228.
Bronson
D L
DL
Estlack
L E
LE
Wians
F H
FH
D001053:Apolipoproteins / Q000378:metabolism*; D001798:Blood Proteins / Q000276:immunology / Q000378:metabolism*; D006063:Chorionic Gonadotropin / Q000378:metabolism; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008649:Mesonephroma / Q000378:metabolism*; D010051:Ovarian Neoplasms / Q000378:metabolism*; D011233:Precipitin Tests; D014407:Tumor Cells, Cultured; D015017:Yolk Sac / Q000378:metabolism; D000509:alpha-Fetoproteins / Q000378:metabolism
D001053:Apolipoproteins; D001798:Blood Proteins; D006063:Chorionic Gonadotropin; D000509:alpha-Fetoproteins