Differential enhancing effects of α2,8-sialyltransferase on the cell proliferation and mobility

a2,8-Sialyltransferase (a2,8S-T, GD3 synthase) has been reported to be involved in the enhanced cell proliferation of malignant tumors. Using a cloned cDNA of a2,8S-T, transfectant cells were established and the effects of the gene expression on the cell phenotypes were analyzed. In contrast with PC12 cells, in which we reported marked growth enhancement based on the transfection of a2,8S-T, Swiss3T3 cells showed no enhancement in either cell proliferation or phosphorylation of MAP kinases after the transfection of a2,8S-T when treated with platelet-derived growth factor. Correspondingly, the receptor for platelet-derived growth factor also showed no increased phosphorylation upon the factor stimulation. However, in the wound-healing scratching assay, the Swiss3T3 transfectant cells demonstrated increased mobility as the PC12 transfectant cells. These results suggest that the enhancing effects of a2,8S-T on the proliferation and mobility are differential depending on the cell types, and ganglioside-associating molecules in the individual cell types need to be investigated.