[A case of cholangiolocellular carcinoma combined with intrahepatic cholangiocarcinoma diagnosed after 4 years follow-up for hepatic hemangioma].

We report a rare case which had been followed up for hepatic hemangioma and in whom was surgical resection revealed with cholangiolocellular carcinoma (CoCC) combined with intrahepatic cholangiocarcinoma (ICC). A 69-year-old man who was an HBV carrier had been regularly followed up with hepatic hemangioma from November, 2005. Because the arterial phase of dynamic CT scan exhibited an enhanced lesion in the dorsal portion of the hemangioma on November, 2009, the patient was admitted for intensive examination of the liver tumor. After surgical resection of the tumor, histological examination revealed small irregular tubules in the outer part and scattered small duct structures in the inner part of the tumor. In addition, immunohistochemical analysis demonstrated that cytokeratin (CK) 7, CK19 and epithelial membrane antigen (EMA) were all positive in the outer part, and EMA was only negative in the inner part of the tumor. From these findings, this case was diagnosed as CoCC combined with ICC.

Efficient transfer of sialo-oligosaccharide onto proteins by combined use of a glycosynthase-like mutant of Mucor hiemalis endoglycosidase and synthetic sialo-complex-type sugar oxazoline.

BACKGROUND: An efficient method for synthesizing homogenous glycoproteins is essential for elucidating the structural and functional roles of glycans of glycoproteins. We have focused on the transglycosylation activity of endo-ß-N-acetylglucosaminidase from Mucor hiemalis (Endo-M) as a tool for glycoconjugate syntheses, since it can transfer en bloc the oligosaccharide of not only high-mannose type but also complex-type N-glycan onto various acceptors having an N-acetylglucosamine residue. However, there are two major bottlenecks for its practical application: the low yield of the transglycosylation product and the difficulty to obtain the activated sugar oxazoline substrate, especially the sialo-complex type one. METHODS: We carried out the transglycosylation using a glycosynthase-like N175Q mutant of Endo-M, which was found to possess enhanced transglycosylation activity with sugar oxazoline as a donor substrate, in combination with an easy preparation of the sialo-complex-type sugar oxazoline from natural sialoglycopeptide in egg yolk. RESULTS: Endo-M-N175Q showed efficient transglycosylation toward sialo-complex-type sugar oxazoline onto bioactive peptides and bovine ribonuclease B, and each sialylated compound was obtained in significantly high yield. CONCLUSIONS: Highly efficient and simple chemo-enzymatic syntheses of various sialylated compounds were enabled, by a combination of a simple synthesis of sialo-complex-type sugar oxazoline and the Endo-M-N175Q catalyzed transglycosylation. GENERAL SIGNIFICANCE: Our method would be very useful for a practical synthesis of biologically important glycopeptides and glycoproteins.