Aberrant expression of pyloric gland-type mucin in mucin-producing bile duct carcinomas: a clear difference between the core peptide and the carbohydrate moiety.
The authors have recently defined the clinopathological entity of a mucin-producing bile duct tumor (MPBT), and divided MPBT into two distinct subtypes: 'columnar-type' and 'cuboidal-type' MPBT. Mucin core protein 6 (MUC6), which is present in normal pyloric glands, had higher expression levels in cuboidal-type tumors than in columnar-type tumors. In the pyloric glands, a carbohydrate antigen detected by monoclonal antibody HIK1083 (CA/HIK1083) is also expressed. In order to evaluate the coexpression pattern of MUC6 and CA/HIK1083 in MPBT, expression profiles were evaluated in 38 surgically excised mucin-producing bile duct carcinomas (MPBC; cuboidal-type, n = 15; columnar-type, n = 23), using immunohistochemistry. The staining rate was graded as follows: -, <5% of neoplastic cells stained; +, 5% to <20%; + +, 20% to <50%; + + +, > or =50%. In cuboidal-type MPBC, MUC6 was positive in all cases (+ + +, 13/15; + +, 1/15; +, 1/15), whereas CA/HIK1083 was negative in all cases (-, 15/15; P < 0.0001). In columnar-type MPBC, MUC6 was positive in 65% of cases (+ + +, 6/23; + +, 8/23; +, 1/23; -, 8/23), and CA/HIK1083 was positive in 52% (+ +, 3/23; +, 9/23; -, 11/23; not significant). Our results clearly demonstrate that cuboidal-type MPBC have an aberrant pyloric glandular phenotype, that is, MUC6+/CA/HIK1083-. This unique profile may be related to different outcomes of patients with MPBC.
Department of Human Pathology, Field of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
Masamichi
M
Goto
Hiroaki
H
Shibahara
Shugo
S
Tamada
Tomofumi
T
Hamada
Koji
K
Oda
Masato
M
Nagino
Tetsuro
T
Nagasaka
Kohzoh
K
Imai
Yuji
Y
Nimura
Suguru
S
Yonezawa
D002288:Adenocarcinoma, Mucinous / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000032:analysis; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000096:biosynthesis / Q000276:immunology; D001650:Bile Duct Neoplasms / Q000378:metabolism / Q000473:pathology*; D017734:Bile Ducts, Extrahepatic / Q000737:chemistry / Q000473:pathology; D002241:Carbohydrates / Q000032:analysis; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D055272:Mucin-6; D009077:Mucins / Q000096:biosynthesis* / Q000737:chemistry; D010455:Peptides / Q000032:analysis
D000911:Antibodies, Monoclonal; D015295:Antigens, Tumor-Associated, Carbohydrate; D002241:Carbohydrates; C524734:MUC6 protein, human; D055272:Mucin-6; D009077:Mucins; D010455:Peptides