GLYCOSYLTRANSFERASES IN METASTASIZING AND NON-METASTASIZING RAT MAMMARY-TUMORS AND THE RELEASE OF THESE ENZYMES IN THE HOST SERA

In order to study the role of glycosyltransferases in the process of metastasis, levels of sialyltransferase and two N-acetylglucosaminyltransferases in three established strains of spontaneously metastasizing rat mammary tumors were compared with four non-metastasizing strains. Activity of sialyltransferase was significantly lower in the metastasizing tumor, while the levels of both the N-acetylglucosaminyltransferases were comparable in the two groups. Levels of five glycosyltransferases were determined in the serially drawn sera of a group of rats bearing a representative metastasizing tumor (SMT-2A), a representative non-metastasizing tumor (MT-W 9B) and a group of control female rats, from the day of tumor transplantation up to the 6th week of tumor development, at weekly intervals. In the sera of rats bearing SMT-2A, the levels of sialyl-and galactosyltransferases were significantly (P < 0.05) elevated from the 3rd to 4th week after tumor transplant; while no such elevation was observed for those bearing MT-W9B, compared to the control group of rats. Levels of two fucosyltransferases, one N-acetylglucosaminyltransferase, were not elevated significantly in any of the tumor bearing rats. No significant change in the levels of protein-bound hexose, fucose or hexosamine was observed in these tumor bearing rats compared to control group. © 1979.