アブストラクト（31巻1号：The Bulletin of Kanagawa Dental College）

The Bulletin of Kanagawa Dental College

English

Title　： Inhibitory Effect of Tamoxifen on DMBA-induced Submandibular Gland Tumors in Rats
Subtitle　： ORIGINAL ARTICLES
Authors　： Satoru Ozono1, Kazuyoshi Sato2, Yumi Ito2
Authors（kana）　：
Organization　： 1Institute for Frontier Oral Science, Kanagawa Dental College, 2Department of Oral Pathology, Kanagawa Dental College
Journal　： The Bulletin of Kanagawa Dental College
Volume　： 31
Number　： 1
Page　： 27-32
Year/Month　： 2003 / 3
Article　： Original article
Publisher　： Kanagawa Odontological Society
Abstract　： We have previously shown that an estrogen receptor (ER) was present in the tumor cell nucleus of 9,10-dimethyl-1, 2-benzanthracene (DMBA)-induced rat submandibular gland tumors. In this study, we histologically investigated the effect of tamoxifen (TAM), a non-steroidal anti-estrogen, on the maintenance and growth of DMBA-induced ER-positive tumors. Tumor-bearing rats were treated for 20 days with daily s. c. injection of 5 mg/kg of TAM in sesame oil. The control group received only sesame oil. Biopsy samples were obtained from all tumors before TAM treatment and processed immunohistochemically for ER. Receptor positivity was defined as any nuclear immunostaining. Of 73 tumors, 45 (61.6%) were ER positive, and 28 were negative. In 29/45 cases there was high positivity; over 50% of tumor cells expressed ER. In ER-positive tumors treated with TAM, 56.7% (17/30) had an extensive or focal disappearance of tumor cells. The administration of TAM to rats with ER-negative tumor showed no detectable changes. Furthermore, the vehicle-treated rats also had no appreciable effect on 15 ER-positive and six negative tumors. These results indicate that the estrogen deprivation through ER antagonism causes an inhibition of DMBA-induced submandibular gland tumors, although there are individual exceptions in tumors with high levels of receptors.
Practice　： Dentistry
Keywords　： Estrogen receptor, Tamoxifen, Immunohistochemistry, DMBA-induced rat submandibular gland tumor