Expression of sialyl Lex, sialyl Lea, Lex and Ley glycotopes in secreted human ovarian cyst glycoproteins

Human blood group A, B, H, Ii, Lea and Leb antigens and their determinants expressed on ovarian cyst glycoproteins have been studied for over five decades. However, little is known about sialyl Lex and sialyl Lea glycotopes, which play essential roles in normal immunity, inflammation, and cancer cell metastasis. Furthermore, Lex and Ley were classified as glycotopes of unknown genes. Identification of these Lewis epitopes was hampered by the lack of specific antibodies. In this study, the occurrence of sialyl Lex, sialyl Lea, Lex and Ley reactivities in cyst glycoproteins was characterized by enzyme-linked immunosorbent assays. The results indicated that most human ovarian cyst glycoproteins carried Lex (8/25) and/or Ley (17/25) glycotopes. The expression (epitopes) of the new genes described in previous reports are Lex and Ley glycotopes; the reactivities of sialyl Lex and sialyl Lea glycotopes in secreted cyst glycoproteins may be affected by the conditions of purification; the relationship between Ley and human blood group ABH was confirmed; recognition profiles of sialyl Lex, sialyl Lea, Lex and Ley present in the carbohydrate chains of water-soluble cyst glycoproteins were illustrated; possible attachments of glycotopes to the internal carbohydrate complex of cyst glycoproteins have been reconstructed; proposed biosynthetic pathways for the formation of sialyl Lea, sialyl Lex, Lex, Ley, ALey and BLey determinant structures on Type I and Type II core structures of human ovarian cyst glycoproteins are also included in this study.