Analysis of glycoproteins released from benign and malignant human breast: changes in size and fucosylation with malignancy.

Radiolabelled glycoproteins released into media from benign and malignant human breast tissue after 48 h organ culture have been analysed using SDS polyacrylamide gel electrophoresis and fluorography. Major differences were identified between benign and malignant tissues: (i) a considerably higher incidence of glycoproteins in the molecular weight range 210-280 kDa detected from carcinomas than benign samples, with incidence being greater in poorly differentiated tumours; (ii) fucosylation of these glycoproteins released from carcinomas but not benign breast; (iii) heterogeneity, particularly of fucosylation, between the carcinomas but consistency amongst benign breast. A glycoprotein of MW 230 kDa was of particular interest since it was not detected from any benign samples but was present in 11 of 17 carcinomas, when it was almost always fucosylated. This could prove to be a useful tumour marker.