Kazuki Takaoka

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The involvement of cyclooxygenase (COX)-2 in oral carcinogenesis and outcome of the patients is not fully understood. To determine whether COX-2 expression could serve as an indicator for them, we examined the expression of COX-2 and DNA topoisomerase (DNA-Topo) II alpha as an index of cell proliferating activity in precancerous and cancerous lesions of the(More)
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(More)
In order to investigate the malignant phenotype of cyclooxygenase (COX)-2 overexpressing cancer cells, a human epidermoid KB carcinoma cell line minimally expressing COX-2 protein was transfected with human COX-2 cDNA. In this study, we used a COX-2 transfected clone KB/COX-2 and a neomycin-transfected clone KB/neo as the control. When we examined the(More)
Colorectal carcinomas are well known to highly express COX-2 and their growth is markedly inhibited by COX-2 inhibitors, but little is known about head and neck carcinomas. In this study, we investigated the effect of a selective COX-2 inhibitor, celecoxib, on growth and apoptosis induction of four human head and neck carcinoma cell lines, SCC25, KB, HSG(More)
BACKGROUND Despite recent advances in the diagnosis and treatment of oral carcinoma, outcomes remain disappointing. The identification of new prognostic factors is necessary to improve survival. To determine the prognostic significance of cyclooxygenase (COX)-2 and DNA topoisomerase (DNA-Topo) IIalpha expression in patients with oral carcinoma, we(More)
Neutrophil gelatinase-associated lipocalin (NGAL, also known as lipocalin2, LCN2) is a secreted glycoprotein with increased expression in solid tumors. The expression and functions of NGAL in oral cancer, however, remain unclear. We investigated the expression of NGAL in oral cancer tissues and oral cancer cell lines. By(More)
Endovascular papillary angioendothelioma (EPA), known as Dabska tumor, is a very rare vascular neoplasm that usually occurs in the skin or subcutis of infants and young children. There is no previous report of EPA appearing in the oral cavity. Here, we present an exceptionally rare case of EPA of the tongue in a 67-year-old man. A well-defined, reddish(More)
In order to investigate the involvement of cyclooxygenase (COX)-2 in cell growth and invasion of oral cancer, a human epidermoid carcinoma cell line KB minimally expressing COX-2 protein was transfected with COX-2 cDNA and these activities were compared with mock-transfected KB in vitro and in vivo. KB/COX-2 clones showed a similar growth rate in vitro(More)
Inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 are major inflammatory mediators. Nitric oxide (NO) produced by iNOS has been shown to have an important role in carcinogenesis. Recent studies have suggested that COX-2 expression also contributes to carcinogenesis, as well as tumor growth, invasion, and metastasis. COX-2 inhibitors such as(More)
The basic histologic patterns of adenoid cystic carcinoma (ACC) are classified into three types (tubular, cribriform and solid), but clinical significance of the histological type is unclear. We have successfully established a human tumor line derived from ACC that is serially transplantable in nude mice. This tumor showed an increased growth rate as the(More)