Differential expression of beta 1,3galactosyltransferases in human colon cells derived from adenocarcinomas or normal mucosa

Two beta 1,3galactosyltransferases are detected in human colon cells: one c orresponds to beta 3GalT1, the other (beta 3GalTx) is found to be different from any cloned beta 3GalT since in vitro it utilizes GlcNAc very efficien tly under specific reaction conditions. Expression of beta 3GalT1 transcrip t is high in normal colon mucosa and control neuroectodermal cells, which d o not express sialyl-Lewis a antigen, and low in colon adenocarcinoma cells , as assessed by competitive RT-PCR. beta 3GalTx activity is high in adenoc arcinoma cells expressing sialyl-Lewis a and undetectable in all other cell s, suggesting differential involvement and opposite regulation of such enzy mes during carcinogenesis. (C) 1999 Federation of European Biochemical Soci eties.