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Cytoplasmic β‐catenin in esophageal cancers
Author(s) -
Kimura Yutaka,
Shiozaki Hitoshi,
Doki Yuichiro,
Yamamoto Makoto,
Utsunomiya Takehiro,
Kawanishi Kenshu,
Fukuchi Nariaki,
Inoue Masatoshi,
Tsujinaka Toshimasa,
Monden Morito
Publication year - 1999
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/(sici)1097-0215(19990420)84:2<174::aid-ijc14>3.0.co;2-e
Subject(s) - catenin , cytoplasm , carcinogenesis , cadherin , biology , pathology , epithelium , cell , microbiology and biotechnology , chemistry , cancer , medicine , biochemistry , genetics , signal transduction , wnt signaling pathway
β‐Catenin has 2 distinct roles in E‐cadherin‐mediated cell adhesion and carcinogenesis through APC gene mutation. One occurs at cell‐adhesion sites, where cadherins become linked to the actin‐based cytoskeleton. The others occur in the cytoplasm and nuclei and are thought to regulate cell transformation. We studied these different β‐catenins and evaluated their significance in carcinogenesis. Fresh surgical specimens were obtained from 22 patients with squamous‐cell carcinoma of the esophagus. β‐Catenin in the free soluble fraction and the insoluble fraction was immunoblotted separately. At the same time, its localization was observed by immuno‐histochemical techniques. In the normal esophageal epithelium, 91% of β‐catenin was detected in the insoluble fraction and β‐catenin staining occurred at the cell membrane, in co‐existence with E‐cadherin. In cancerous tissues, the amount of soluble β‐catenin was significantly (about 4‐fold) higher than in normal tissues. Also, in cancerous tissues with higher amounts of soluble β‐catenin, immuno‐histochemical techniques revealed the presence of β‐catenin in the cytoplasm and nuclei, as well as in the cell membrane. However, in samples with lower amounts of β‐catenin, expression was found only at the cell boundaries. The amount of soluble β‐catenin was not associated with the clinico‐pathological grading of the tumors. Our results show that the accumulation of free soluble β‐catenin in the cytoplasm and nuclei frequently occurs during carcinogenesis of the squamous epithelium of the esophagus. Int. J. Cancer (Pred. Oncol.) 84:174–178, 1999. © 1999 Wiley‐Liss, Inc.