ELEVATED ACTIVITY OF N-ACETYLGLUCOSAMINYLTRANSFERASE-V IN HUMAN HEPATOCELLULAR-CARCINOMA

Cell-surface glycoproteins are regarded as candidates for involvement in the spread of tumor cells. N-linked beta 1-6 branched oligosacchari des may contribute directly to the malignant or metastatic phenotypes of tumor cells. Increased beta 1-6 branching has been associated with an increased level of N-acetylglucosaminyltransferase V (GlcNAc transf erase V), the glycosyltransferase that initiates the beta 1-6 branchin g. In this report, 33 pathologically verified hepatocellular carcinoma (HCC) specimens, six non-cancerous tissues surrounding HCC and five n ormal liver specimens have been studied. We have quantified N-linked b eta 1-6 branched oligosaccharides indirectly by measuring GlcNac trans ferase V activity. The average GlcNac transferase V activities in hepa tocellular carcinoma (HCC), noncancerous tissues surrounding HCC and n ormal liver tissues were 324.2 +/- 269.8, 84.8 +/- 20.7 and 7.0 +/- 6. 2 pmol product h(-1) mg protein(-1) (P < 0.05) respectively. In additi on, the activity was correlated with the TNM classification of HCC. Th e average activities of GlcNAc transferase V in stages T1, T2-3 and T4 were 77.6 +/- 57.8, 369.0 +/- 294.7 and 329.9 +/- 205.9 pmol product h(-1) mg protein h(-1) respectively (P < 0.05), showing that the activ ity of the enzyme in advanced HCC was higher than that in early HCC. O ur preliminary results indicated that GlcNAc transferase V activity in creased in human HCC and was correlated with its progression.