title: Association between expression levels of CA 19-9 and N-acetylglucosamine-beta;1,3-galactosyltransferase 5 gene in human pancreatic cancer tissue.
abstract: OBJECTIVE
  CA 19-9, equivalent to Sialyl Lewis antigen, is a well-known tumor marker in pancreatic cancer. At the initial step of the biosynthesis of CA 19-9, N-acetylglucosamine-beta1,3-galactosyltransferase (beta3Gal-T) transfers galactose to N-acetylglucosamine (GlcNAc). Recently, beta3Gal-T5 has been presumed to be related to the formation of the type 1 chain in an in vitro experiment in terms of kinetic enzyme characterization. The purpose of this study was to investigate which beta3Gal-T is related to the synthesis of CA 19-9 in human pancreatic cancer tissues.
  
  
  METHODS
  We examined beta;3Gal-T1, T2, T3, T4, and beta;3Gal-T5 mRNA expressions in 13 noncancerous and cancerous tissues of the human pancreas using real-time polymerase chain reaction, and compared those gene expression levels with the immunoreactivity of CA 19-9 and its precursor DUPAN-2 in cancerous tissues.
  
  
  RESULTS
  Beta;3Gal-T5 gene expression significantly augmented in cancerous tissues, when compared with the adjacent noncancerous tissues. Additionally, there was a good correlation between BETA;3GAL-T5 gene transcription levels and immunohistochemical grades of CA 19-9 or its precursor DUPAN-2 in cancerous tissues. However, no correlation was observed between beta;3Gal-T1, T2, T3, and beta;3Gal-T4 gene expression levels and CA 19-9 or DUPAN-2 immunoreactive grades in cancerous tissue.
  
  
  CONCLUSIONS
  beta3Gal-T5 is presumed to be responsible for the synthesis of CA 19-9 in pancreatic cancer tissue.
authors.affiliation: Department of Surgery and Clinical Oncology, Graduate School of Medicine, Osaka University, Osaka, Japan.
authors.forename: Nobuyasu
authors.initials: N
authors.lastname: Hayashi
authors.forename: Shoji
authors.initials: S
authors.lastname: Nakamori
authors.forename: Jiro
authors.initials: J
authors.lastname: Okami
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nagano
authors.forename: Keizo
authors.initials: K
authors.lastname: Dono
authors.forename: Koji
authors.initials: K
authors.lastname: Umeshita
authors.forename: Masato
authors.initials: M
authors.lastname: Sakon
authors.forename: Hisashi
authors.initials: H
authors.lastname: Narimatsu
authors.forename: Morito
authors.initials: M
authors.lastname: Monden
mesh_terms: D000368:Aged; D000951:Antigens, Neoplasm / Q000096:biosynthesis; D018395:CA-19-9 Antigen / Q000096:biosynthesis*; D005260:Female; D005700:Galactosyltransferases / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D012150:Polymorphism, Restriction Fragment Length; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000951:Antigens, Neoplasm; D018395:CA-19-9 Antigen; C042317:DU-PAN-2 antigen, human; D012333:RNA, Messenger; C479886:B3GALT5 protein, human; D005700:Galactosyltransferases