Altered mRNA expression of glycosyltransferases in human colorectal carcinomas and liver metastases

BACKGROUND/AIMS Biosynthesis of carbohydrate structures is tissue specific and developmentally regulated by glycosyltransferases such as fucosyltransferases, sialyltransferases, and N-acetylgluco- saminyltransferases. During carcinogenesis, aberrant glycosylation leads to the development of tumour subpopulations with different adhesion properties. Therefore alterations in glycosyltransferase mRNA expression in colorectal carcinomas were examined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). METHODS Colorectal carcinoma specimens were classified and characterised according to the WHO/UICC system. Expression of fucosyltransferases FT-I, FT-III, FT-IV, FT-V, FT-VI, and FT-VII, sialyltransferases ST3Gal-I, ST3Gal-III, ST3Gal-IV, and ST6Gal-I, β1,4-galacto- syltransferase, and β1,6-Nacetylgluco- saminyltransferase V (GNT-V) was screened simultaneously in extracts of 22 homogenised tumour specimens by RT-PCR and compared with corresponding mucosa from each patient. Also 12 adenomas and 17 liver metastases of colorectal carcinomas were examined. RESULTS GNT-V expression was enhanced in colorectal adenomas (p = 0.039), carcinomas (p