[Altered expression of Lewis antigens associated with malignant transformation in endometrial tissues]

Fetal, normal adult, and malignant tissues of the uterine endometrium were examined by immunoperoxidase staining for Lewis antigens. Pronounced expression of Lewis-a, Lewis-b, and Lewis-Y antigens in malignant tissues was observed, compared with that in normal adult tissues. Moreover, the amplified expression of Lewis-b antigen was considerably higher than that of Lewis-a and Lewis-Y antigens. On the other hand, Lewis-X antigen was less expressed in malignant tissues than in normal adult tissues. These results suggest that fucose-transferase activity might be increased in malignant tissues and that the type I carbohydrate chain may play a role in the malignant transformation. In addition, Lewis-b and Lewis-Y antigens can be considered to be oncofetal antigens since they were frequently expressed in fetal and malignant tissues, but not in normal adult tissues. However, the functional significance of these changes in the expression of Lewis antigens remains to be investigated.