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Significance of aberrant (cytoplasmic/nuclear) expression of beta‐catenin in pancreatoblastoma
Author(s) -
Tanaka Yukichi,
Kato Keisuke,
Notohara Kenji,
Nakatani Yukio,
Miyake Tetsumi,
Ijiri Rieko,
Nishimata Shigeo,
Ishida Yuji,
Kigasawa Hisato,
Ohama Yokatsu,
Tsukayama Choutatsu,
Kobayashi Yasutsugu,
Horie Hiroshi
Publication year - 2003
Publication title -
the journal of pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.964
H-Index - 184
eISSN - 1096-9896
pISSN - 0022-3417
DOI - 10.1002/path.1262
Subject(s) - cyclin d1 , biology , adenomatous polyposis coli , cytoplasm , microbiology and biotechnology , catenin , cell nucleus , cyclin , cyclin d , beta catenin , nuclear localization sequence , cancer research , gene expression , immunohistochemistry , pathology , gene , cell cycle , wnt signaling pathway , cancer , colorectal cancer , immunology , genetics , medicine
This study concerns the significance of aberrant (nuclear/cytoplasmic) expression of beta‐catenin in pancreatoblastoma (PBL). On immunohistochemistry, all seven PBLs examined showed nuclear/cytoplasmic expression of beta‐catenin, predominantly in the squamoid corpuscles (SCs). In areas with acinar/ductular differentiation, few tumour cells displayed nuclear/cytoplasmic expression of beta‐catenin and more than half of the tumour cells showed membranous expression. Two out of five (40%) tumours examined showed missense mutations in codons 33 and 37 of exon 3 of the beta‐catenin gene. No mutation of the adenomatous polyposis coli (APC) gene was detected in two of the remaining three tumours. Amplifiable DNA for APC analysis was not obtained from the one other tumour. Immunoreactivity for cyclin D1, one of the nuclear targets of beta‐catenin, was found predominantly in the SCs of the seven tumours. In contrast, the Ki‐67 labelling index was 2–4% (median 3%) in the SCs and 8–18% (median 12%) in the other areas, indicating a negative correlation with nuclear cyclin D1 reactivity. These results imply that in PBLs, nuclear/cytoplasmic accumulation of beta‐catenin and overexpression of its target gene cyclin D1 are not associated with the induction of tumour cell proliferation. Nuclear/cytoplasmic accumulation of beta‐catenin may be related to the morphogenesis of the SCs that are considered most characteristic for PBL. Copyright © 2002 John Wiley & Sons, Ltd.