Characterization of an established cell line from human immature teratoma of the ovary and effects of retinoic acid on cell proliferation.

A human immature teratoma cell line was established from tumor tissue of the ovary. The cell line, designated YK , synthesized and secreted alpha-fetoprotein, but there was a gradual decrease in the synthesis of this protein during serial passage. The doubling time at passage 43 was about 20.3 hr, and the plating efficiency was 30 to 40%. Tumorigenicity of the cell line in athymic nude mice was 100% even when 10(4) cells were inoculated s.c. When the cell line was cultivated for 5 days in the presence of 80 microM retinoic acid, proliferation was completely inhibited, while alpha-fetoprotein secretion into the medium was increased. Specific lactate dehydrogenase activity in the tumor grown in nude mice as well as in the cultured cells was 8 times higher than that in the original tumor. The activity of alpha-hydroxybutyrate dehydrogenase in the original tumor was similar to that in the tumor grown in nude mice, while the activity in the cultured cells was about 2.5 times higher than those in both original tumor and the tumor grown in nude mice. The original tumor had all five ordinary bands of lactate dehydrogenase isoenzymes. In contrast, both the cultured cells and the tumor grown in nude mice had a characteristic band which was considered to have similar electrophoretic mobility as testicular lactate dehydrogenase X isoenzyme in humans.