GANGLIOSIDE COMPOSITION OF MALIGNANT AND ACTINOMYCIN D-RESISTANT NONMALIGNANT CHINESE-HAMSTER CELLS

The ganglioside composition of three Chinese hamster cell lines was investigated. The parental spontaneously transformed DC-3F cell line has a full complement of gangliosides from hematosides to disialogangliosides. An actinomycin D-resistant subline, DC-3F/AD X, which lost its tumorigenicity and regained a normal morphology and growth pattern in cell culture, exhibits only hematosides. A third cell line, derived from the latter and grown in the absence of actinomycin D for 3 years, regained tumorigenicity and displays a ganglioside profile similar to that of the malignant parental cell line. In addition, tumors formed from DC-3F cells grown in athymic nude mice have a ganglioside profile similar to that exhibited by the malignant cells in culture. The results suggest that the ganglioside composition of these spontaneously transformed, tumorigenic Chinese hamster cells differs from that of the majority of transformed cell lines reported in the literature in that our malignant cells are not blocked in higher ganglioside biosynthesis. We also find that the experimentally derived, nontumorigenic cells with a high degree of acquired resistance to actinomycin D are blocked at the level of hematosides. © 1979.