ABO blood group antigens in oral mucosa. What is new?
Histo-blood group ABH (O) antigens are major alloantigens in humans. These antigens are widely distributed in human tissues and undergo changes in expression during cellular differentiation and malignant development. The ABH antigens have been characterized as terminal disaccharide determinants which represent secondary gene products. They are synthesized in a stepwise fashion from a precursor by the action of different glycosyltransferases. In non-keratinized oral mucosa, a sequential elongation of the carbohydrates is associated with differentiation of epithelial cells, resulting in expression of precursors on basal cells and A/B antigens on spinous cells. Reduction or complete deletion of A/B antigen expression in oral carcinomas has been reported, a phenotypic change that is correlated with invasive and metastatic potential of the tumours and with the mortality rates of the patients. Disappearance of the antigens is ascribed to the absence of A or B transferase gene expression. Several studies have shown that loss of A and B antigen expression is associated with increased cell motility, invasion in matrigel, and tumourigenecity in syngenic animals. In vivo studies of human oral wound healing show similarly decreased expression of A/B antigens on migrating epithelial cells. Some studies suggest that the relationship between expression of blood group antigens and cell motility can be explained by different degrees of glycosylation of integrins. Changes in ABO expression in tumours have, in some cases, been due to the A/B gene promoter, although little is known about the regulation of A, and B expression, in normal tissue.
Dabelsteen
Erik
E
Department of Oral Diagnostics, School of Dentistry, Faculty of Health Sciences, Copenhagen, Denmark. erik.dabelsteen@odont.ku.dk
D000017:ABO Blood-Group System / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology*; D000818:Animals; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000097:blood* / Q000235:genetics / Q000276:immunology; D002471:Cell Transformation, Neoplastic; D019175:DNA Methylation; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D005964:Glucosyltransferases / Q000096:biosynthesis; D006031:Glycosylation; D006801:Humans; D007983:Lewis Blood Group Antigens / Q000235:genetics / Q000502:physiology; D009061:Mouth Mucosa / Q000276:immunology* / Q000378:metabolism; D009062:Mouth Neoplasms / Q000097:blood* / Q000235:genetics / Q000276:immunology
D000017:ABO Blood-Group System; D015295:Antigens, Tumor-Associated, Carbohydrate; D007983:Lewis Blood Group Antigens; D005964:Glucosyltransferases