Correlation of glycosyltransferases mRNA expression in extrahepatic bile duct carcinoma with clinical pathological characteristics

BACKGROUND: The incidence of extrahepatic bile duct carcinoma (EBDC) has been increasing, especially in aged people, but the glycobiology of the tumor is not elucida- ted. In this study we investigated the expressions of three glycosyltransferases in 35 patients with EBDC and 35 pa- tients with benign biliary duct disease (BBDD) as well as their clinicopathological significance. METHOD: The patients were divided into several sub- groups by tumor differentiation, TNM stage, and invasion by the standards recommended by UICC. Tumor samples were immediately frozen in liquid nitrogen after resection, followed by mRNA determination of enzymes in the tissue using a mRNA selective reverse trancriptase-polymerase chain reaction kit. The mRNA levels of different groups were semi-quantitatively compared. RESULTS: The mRNA levels of N-acetylglucosaminyltrans- ferase V (GnT-V) and a subtype of α2,3 sialyltransferases for N-glycans, ST3Gal- were elevated 7.75 and 5.39 times in EBDC as compared with BBDD, respectively, and they were correlated to several clinicopathological factors including tumor advancement, differentiation, metastasis, and invasiveness. The mRNA expression of another sialyl- transferase, ST6Gal- , was also 0.63-fold higher in EBDC than in BBDD, but not involved in the clinicopathological characteristics. CONCLUSION: The elevated expression of these three gly- cosyltransferases can be considered as an important molecu- lar event in the occurrence and progression of EBDC.