Reduced Expression of Gangliosides with GM2-determinant in Cervical Carcinoma-Derived Cells after Subcutaneous Transplantation into Nude Mice

Human cervical carcinoma-derived cell lines have been frequently found to contain gangliosides with GM2-determinant, i.e., GM2, GalNAc-GM1b and GalNAc-GD1a, but GM2 was only detected in 5 of 15 tissues, and GalNAc-GM1b and GalNAc-GD1a were not found in any tissues from patients with several histological types of cervical carcinomas. To further characterize the ganglioside expression in cervical carcinomas, cells were grown by subcutaneous transplantation into nude mice, and gangliosides were quantitated by TLC-immunostaining with the anti-GM2 (YHD-06) antibody and a newly developed anti-GM3 (5H6) antibody, which reacts with GM3 and GM1b, but not with GD1a. Gangliosides with GM2-determinant in cells disappeared in transplanted cells, and the amount of GM3, a precursor for GM2, in transplanted cells was greater than in cultured cells. Also, transplanted cells containing GalNAc-GM1b newly expressed GM1b, suggesting that the activity of GalNAc transferase for synthesis of GalNAc-GM1b is retarded on subcutaneous transplantation. The ganglioside composition, with GM3 as the major one, in the transplanted cells was similar to that in cervical carcinoma tissues, and thus, the expression of gangliosides with GM2-determinant seemed to be accelerated under cell-cultivation conditions.