ELEVATION OF GLYCOPROTEIN GALACTOSYLTRANSFERASE ACTIVITY IN HUMAN-LUNG CANCER RELATED TO HISTOLOGICAL TYPES

Abstract

Uridine diphosphogalactose:glycoprotein galactosyltransferases were examined in human lung adenocarcinoma and squamous cell carcinoma. The galactosyltransferase activities in tissue homogenates from both carcinomas were higher than in adjacent normal control with asialoagalactofetuin as a substrate. This activity in adenocarcinoma (27 cases) was 2 times higher than that in squamous cell carcinoma (19 cases) with statistical significance (P < 0.001). Using Triton-solubilized enzymes from a particulate fraction, similar differences in the activity were observed with ovalbumin, asialoagalactofetuin and its .beta.-eliminated derivative as acceptors but not with bovine submaxillary mucin. The higher activity of galactosyltransferase(s) in lung carcinomas (especially in adenocarcinoma) is mainly responsible for galactosylation of carbohydrate chains in N-glycoside-type but not O-glycoside-type glycoproteins.