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Increased expression of cyclooxygenase (COX)‐2 in DMBA‐induced hamster cheek pouch carcinogenesis and chemopreventive effect of a selective COX‐2 inhibitor celecoxib
Author(s) -
Nishimura Norihiko,
Urade Masahiro,
Hashitani Susumu,
Noguchi Kazuma,
Manno Yukiyo,
Takaoka Kazuki,
Sakurai Kazunari
Publication year - 2004
Publication title -
journal of oral pathology and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 83
eISSN - 1600-0714
pISSN - 0904-2512
DOI - 10.1111/j.1600-0714.2004.00254.x
Subject(s) - dmba , celecoxib , cheek pouch , carcinogenesis , hamster , cyclooxygenase , angiogenesis , immunohistochemistry , cancer research , cancer , medicine , pathology , endocrinology , biology , enzyme , biochemistry
Background: In recent years, overexpression of cyclooxygenase (COX)‐2 protein and mRNA has been reported in various cancer tissues. Therefore, it has been suggested that COX‐2 is related to carcinogenesis. Methods: Hamsters were treated by painting a buccal pouch with a 0.5% DMBA solution dissolved in acetone. Basal diet or diets containing 150, 500 and 1500 ppm of celecoxib, a selective COX‐2 inhibitor, were given ad libitum to hamsters, and tumor development was observed. Results: Immunohistochemical and Western blot analyses revealed that COX‐2 expression was increased toward the carcinogenesis. Although all hamsters developed squamous cell carcinoma, the onset of tumor formation was delayed in a dose‐dependent manner. Also, tumor growth was retarded and survived animals were increased in the group of celecoxib treatment. Histologically, administration of celecoxib increased the apoptotic cells in the tumor parenchyma and significantly inhibited the angiogenesis in the stroma. Conclusions: The COX‐2 expression was increased during hamster cheek pouch chemical carcinogenesis. Administration of celecoxib demonstrated the chemopreventive potential against the carcinogenesis.