Nuclear localization of beta-catenin involved in precancerous change in oral leukoplakia.
BACKGROUND
Oral leukoplakia is a precancerous change developed in the oral mucosa, and the mechanism that oral leukoplakia becomes malignant through atypical epithelium is not known. Here we compared the beta-catenin expression detected by immunohistochemical staining in the normal oral epithelium and in the oral leukoplakia with or without dysplasia.


RESULTS
The normal oral epithelium showed beta-catenin expression only in the cell membrane, but not in the nuclei. In the oral leukoplakia without dysplasia, 7 out of 17 samples (41%) showed beta-catenin expression in the cell membrane, and 5 samples (29%) showed expression in the nuclei. In the oral leukoplakia with dysplasia, nuclear expression of beta-catenin was shown in 11 out of 12 samples (92%). Incidence of nuclear beta-catenin expression was significantly different between dysplasia and normal oral epithelium (P < 0.01), and also between oral leukoplakia with dysplasia and those without dysplasia (P < 0.01). Wnt3 expression was detected in the epithelial cell membrane or cytoplasm in oral leukoplakia where nuclear expression of beta-catenin was evident, but not in epithelial cells without nuclear expression of beta-catenin.


CONCLUSIONS
The components of canonical Wnt pathway, such as Wnt3, beta-catenin, and cyclin D1, were detected, implying that this pathway is potentially involved in the progression of dysplasia in oral leukoplakia.
Ishida
Kosei
K
Department of Oral Surgery, Kawasaki Medical School, Kurashiki 701-0192, Japan. kishida@med.kawasaki-m.ac.jp
Ito
Satoshi
S
Wada
Naoyuki
N
Deguchi
Hiroyo
H
Hata
Tsuyoshi
T
Hosoda
Masaru
M
Nohno
Tsutomu
T
D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology; D002467:Cell Nucleus / Q000378:metabolism* / Q000473:pathology; D056741:Cyclin D; D016213:Cyclins / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D007972:Leukoplakia, Oral / Q000378:metabolism* / Q000473:pathology; D009061:Mouth Mucosa / Q000473:pathology; D009062:Mouth Neoplasms / Q000378:metabolism / Q000473:pathology; D011230:Precancerous Conditions / Q000378:metabolism* / Q000473:pathology; D051176:beta Catenin / Q000378:metabolism*
C495270:CTNNB1 protein, human; D056741:Cyclin D; D016213:Cyclins; D051176:beta Catenin