earticle

영어

Mucin type O-glycans have been implicated to have important role in tumorigenesis. There are four different major mucin type O-glycans. Initially, both core1 and core3 structure are synthesized from Tn-antigen (GalNac-Ser/Thr) by β3 galactose transferase and β3 N-acetylglucosamintransferase 6, respectively. Core4 structure is made by single enzyme, core2 N-acetylglucosamintranseferase2 from core3 structure, but three different enzymes, core2 N-acetylglucosamintransferase1, 2, and 3 exist in synthesizing core2 structure based on core1 structure. Each core structure is expressed differentially in conjunction with the differentiation and malignant transformation of various cells and tissues (Brockhausen, 1999). Analyzing the each function of cell surface glycans is critical for evaluating of physiological roles of carbohydrate in cell migration and invasion, which is important for cancer therapy. Core3 synthase which is a unique glycosyltransferase for core3 structure, GlcNacβ1,3-GalNacɑ-Ser/Thr, was cloned through EST screening and reported to have restricted distribution, mainly to the stomach, colon, and small intestine (Iwai et al., 2002). Core3 structure was reported that it is very important cell surface glycan structure for gastric track disease such as colitis (An et al., 2007). Iwai et al. showed forced expression core3 synthase into human fibrosarcoma HT1080 FT-10 cell results in reduced tumor formation. To explain the molecular mechanisms how increased core3 structure modulate the tumorigenesis, Lee et al. (2009) analyzed the effect of core3 structure on ɑ2β1 integrin, which is an important molecule in cell migration and signaling. Core2 O-glycan structure is reported to have important functions in gastrointestinal track in vivo (Stone et al. 2009) and it has important roles in the maturation of gastrointestinal epithelial cell by regulating the cell surface expression of sucrase isomaltase and dipeptidyl peptidase IV (Lee et al 2010). Those results indicate the possibility that mucin-type O-glycans should have important roles in many biological events.