제 2 회 한국 키틴 , 키토산연구회 심포지움 Proceeding : 사람 간암 및 대장암세포에서 암당쇄항원합성효소 N-acetylglucosaminyltransferase-3 과 V 활성의 특이적 발현 : 악성화과정중 암특이당쇄항원의 의미와 억제 = Differential Expression of N-Acetylglucosaminyltransferase-3 and - V Activities in Human Hepatoma Cells and Colon Cancer Cells : Implication of Cancer Specific - Glycoantigen Synthesis in Malignant Transformation

다국어 초록 (Multilingual Abstract)

UDP-N-Aacetylglucosamine:α-6-D-mannoside β-1,6N-acetylglucosaminyltransferase-Ⅲ (GlcNAc-transferase-Ⅲ) and UDP-N-Aacetylglucosamine : α-6-D-mannoside β-1,6N-acetylglucosaminyltransferase - V (GlcNAc -transferase - V )activities were determined in human hepatoma cell lines of Hep3B and HepG2, and also compared with those of normal liver tissues and primary hepatocytes. GlcNAc-transferase-Ⅲ activities were higher than those of GlcNAc-transferase-V in hepatic carcinomca cells. In contrast, the two enzyme activities were assayed in highly metastatic colon cancer cells, GlcNAc-transferase-V activities were much higher than those of GlcNAc-transferase-Ⅲ . When GlcN,GlcN-biant-PA and UDP-GlcNAc were used as substrates, the enzymes displayed different kinetic properties between hepatic and colon cancer cells, depending on their metastatic potentials. Normal cells of two origins are characterized by a very low level of GlcNAc-transferase- Ⅲ and -V activities, whereas hepatoma and colon cancer cells cotained high activities. These data were supported by reverse transcription-polymerase chain reaction results, showing that expression of the GlcNAc-transferase-Ⅲ and V mRNAs increased in proportion to the enzymatic activities. Although the mechanism underlying the induction of this enzymes is unknown, lectin blot analysis showed that oligosaccharides in many glycopnteins were observed in cancer cells. Thus, this is the first demonstration of GlcNAc-transferase-Ⅲ and V activities in human hepatoma and colon cell lines. Molecular aspects of two GlcNAc-transferases in tumorigenesis and metastasis will be extensively discussed.