Changes in N-acetylglucosaminyltransferase III, IV and V in renal cell carcinoma

The activities of N-acetylglucosaminyltransferase (GnT) III, IV and V were determined in 10 cases of renal cell carcinoma (RCC) and compared with the normal kidney cortex (NKC) regions of the same kidney resected from RCC patients. It was found that the GnT III and GnT IV activities decreased consistently in all samples of RCC, while GnT V activity increased, decreased or did not change in different samples. The mean levels of GnT III and GnT IV activities in RCC were found to be very significantly lower than those of NKC on statistical analysis, but the mean value of GnT V activity was almost identical in RCC and NKC. The decrease in GnT activities in RCC were compatible with the decrease in bisecting N-acetylglucosamine (GlcNAc) and antennary number of complex-type N-glycans in gamma-glutamyltranspeptidase (gamma-GT) partially purified from RCCs as studied with concanavalin A (ConA) affinity column chromatography, which showed a decrease of unbound fraction and increase of bound fractions.