Alteration of N-acetylglucosaminyltransferases in pancreatic carcinoma

The activities of three N-acetylglucosaminyltransferases (GnT HI, GnT IV an d GnT V) were determined in 10 samples of pancreatic carcinoma (PCa) and co mpared with those in 9 samples of normal pancreatic tissue (NP). It was fou nd that the specific activities of GnT III, GnT IV and GnT V increased in a ll of the PCa samples. GnT ill increased most significantly, up to 22.3 fol d of normal, GnT IV was elevated 12.3 fold, while GnT V increased only 2.4 fold. The elevation of GnTs in pancreatic carcinoma was consistent with the increase in the number of antenna and bisecting GlcNAc structures in N-gly cans of pancreatic ribonuclease (RNase) as assessed by Con A affinity chrom atography. Polycytidylate specific RNase from the serum of PCa patients sho wed the same structural changes as that found in in N-glycans of the RNase from PCa tissue.