GaINAc glycoprotein expression by breast cell lines, primary breast cancerand normal breast epithelial membrane

Over-expression of N-acetylgalactosamine glycoproteins as detected by bindi ng of the lectin from Helix pomatia (HPA), is associated with metastatic co mpetence and poor patient prognosis in a range of human adenocarcinomas. Th ese glycoproteins remain poorly characterised, and their functional role ha s yet to be elucidated. This study describes characterisation of a range of human breast/breast cancer cell lines for the expression of the N-acetylga lactosaminylated glycoproteins of interest, and their comparison with norma l breast epithelium and a range of clinical breast carcinoma samples. Confo cal and light microscopy studies revealed cytochemical HPA-binding patterns consistent with a fundamental disruption in normal glycoblosynthetic pathw ays attending increasing metastatic potential. We report the most complete comparative analysis of HPA-binding ligands from cultured breast cells, cli nical breast carcinoma samples and normal breast epithelium to date. Lectin blotting identified 11 major HPA-binding glycoprotein bands common to both clinical tumour samples and breast cell lines and 6 of these bands were al so expressed by samples of normal breast epithelium, albeit at much lower l evels. Moreover, very marked quantitative but not qualitative differences i n levels of expression consistent with metastatic capability were noted. (C ) 2001 Cancer Research Campaign http://www.bjcancer.com.