Glycosphingolipid expression on murine L1-fibrosarcoma cells: analysis of clonal in vivo and in vitro selected sublines with different lung colonisation potential.
The patterns of acidic and neutral glycosphingolipids (GSLs) were examined in a syngeneic tumour system in Balb/c mice consisting of closely related cell lines with different colonisation potentials directed to the murine lungs (in vivo selected highly metastatic sublines of L1-fibrosarcoma cells and their WGA-resistant mutants with low metastatic potential). GSLs were analysed by high-performance thin-layer chromatography and structurally identified by fast atom bombardment mass spectrometry combined with compositional analyses and exo-glycosidase digestion. The results suggest that highly metastatic sublines L1-LM and L1-LM12 derived by in vivo selection from mouse fibrosarcoma cells (cell line L1) exhibit a drastic increase of polar ganglioside expression and a restriction to globo-series GSLs. Contrasting with this the low metastatic mutant cells (L1-LM13WGA) express a reduced portion of acidic GSLs and exhibit a shift to less polar ganglioside components. Total cellular and plasma membrane-integrated GSLs were demonstrated to exhibit largely identical patterns. Concomitant with a significant decrease in LacCer expression a substantial reduction of GM2 and a complete lack of GM3 expression can be assigned to the highly metastatic sublines of L1-cells. On the other hand, the more polar gangliosides GM1a and, to an even greater extent, GD1a (exceeding 70% of total gangliosides) accumulate on L1-LM and their clonal sublines. The shift to acidic GSLs of higher polarity is less pronounced on the low metastatic WGA-resistant mutant cells (L1-LM13WGA) showing a preponderance of GM1a. The portion of GD1a within the fractions of acidic GSLs does not correspond to the cellular activities of CMP-NeuAc/GM1 (alpha 2-3) sialyltransferase measured for high and low metastatic cell variants. Total sialic acid content of the various cell lines differs, but is not associated with the metastatic potential. Gangliosides on L1-cells exhibit a significant substitution of N-glycolyl for N-acetylneuraminic acid (13%) compared to their metastatic sublines and to mutant cells (less than 1%). A conversion of surface exposed GD1a to GM1a on membranes of metastatic cells by in situ treatment with Vibrio cholerae sialidase is associated with a significant reduction of tumour cell colonisation directed to the murine lungs.
Hanisch
F G
FG
Institute of Immunobiology, University Clinic of Cologne, Federal Republic of Germany.
Sölter
J
J
Jansen
V
V
Lochner
A
A
Peter-Katalinic
J
J
Uhlenbruck
G
G
D000818:Animals; D001345:Autoradiography; D002461:Cell Line, Transformed; D002851:Chromatography, High Pressure Liquid; D005354:Fibrosarcoma / Q000032:analysis* / Q000378:metabolism / Q000556:secondary; D005677:G(M1) Ganglioside / Q000032:analysis / Q000378:metabolism; D005678:G(M2) Ganglioside / Q000032:analysis / Q000378:metabolism; D005679:G(M3) Ganglioside / Q000032:analysis / Q000378:metabolism; D006028:Glycosphingolipids / Q000032:analysis* / Q000378:metabolism; D008175:Lung Neoplasms / Q000556:secondary*; D008297:Male; D008563:Membrane Lipids / Q000032:analysis* / Q000378:metabolism; D051379:Mice; D014407:Tumor Cells, Cultured / Q000032:analysis / Q000378:metabolism
D005679:G(M3) Ganglioside; D006028:Glycosphingolipids; D008563:Membrane Lipids; D005678:G(M2) Ganglioside; D005677:G(M1) Ganglioside