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ABSTRACT: Oral cancer cells have a significantly augmented nuclear factor-κB (NF-κB) activity and the inhibition of this activity suppresses tumor growth. Bortezomib is a proteasome inhibitor and a drug used for molecular-targeted therapy (targets NF-κB). In this study, we investigated whether bortezomib would be effective as an inhibitor of proliferation and a radiosensitizer for the treatment of oral cancer. We demonstrate that bortezomib inhibits NF-κB activity and cell proliferation. The combined treatment with bortezomib and radiation (RT) suppressed NF-κB activity and cell growth in vitro and in vivo compared with RT treatment alone. To investigate the mechanisms by which bortezomib suppresses tumor growth, the expression of signaling molecules downstream of NF-κB were examined by ELISA. The combined treatment significantly inhibited the radiation‑induced production of angiogenic factors and decreased the number of blood vessels in the tumor tissues. Although the expression of anti‑apoptotic proteins was upregulated by RT, bortezomib downregulated the RT-induced expression of these proteins. Moreover, the expression of cleaved poly(ADP‑ribose) polymerase in vitro and in vivo was enhanced by bortezomib, indicating that bortezomib inhibits tumor growth by inducing apoptosis. This study clearly demonstrates that bortezomib significantly inhibits tumor growth and that the combined treatment with bortezomib and RT results in a significant inhibition of tumor growth. The mechanisms underlying the inhibition of tumor growth by bortezomib include the suppression of angiogenesis and the induction of apoptosis. A novel molecular targeting therapy including bortezomib may be effective in the treatment of oral cancer by suppressing NF-κB activity.
International Journal of Oncology 01/2013; · 2.40 Impact Factor
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ABSTRACT: Salivary gland cancers (SGCs) frequently metastasize to cervical lymph nodes and distant organs. Currently, the mechanisms responsible for the metastatic behavior of SGC cells are not fully understood. We previously demonstrated that the stromal cell-derived factor-1 (SDF-1; also known as CXCL12)/CXCR4 system is involved in the establishment of metastasis in oral squamous cell carcinoma. In the present study, we investigated the role of CXCR4 in the metastatic behavior of SGCs. We examined the expression of CXCR4 mRNA and protein in human SGC cell lines by quantitative RT-PCR and western blotting, respectively. The expression of CXCR4 mRNA and protein were frequently upregulated in 5 out of 6 SGC cell lines. Functional CXCR4 expression was demonstrated by the ability of these SGC cell lines to migrate toward an SDF-1 gradient. SDF-1 rapidly activated extracellular signal-regulated kinase (ERK)1/2 in SGC cell lines. Immunohistochemical analysis revealed that CXCR4 protein expression was detected in either the nucleus or cytoplasm of cancer cells in 16 out of 20 tissues of adenoid cystic carcinoma (ACC) and in 4 out of 6 tissues of mucoepidermoid carcinoma, which are representative of SGC. Furthermore, ACC cell lines exhibited dramatic metastasis to the lung following intravenous inoculation, whereas AMD3100, a CXCR4 antagonist, significantly inhibited lung metastasis of the cells, ameliorated body weight loss and improved the survival rate of tumor-bearing nude mice. These results indicate that CXCR4 expression contributes to the metastatic potential of SGCs.
Clinical and Experimental Metastasis 07/2012; · 3.52 Impact Factor
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Tetsuya Tamatani,
Tarannum Ferdous,
Natsumi Takamaru,
Kanae Hara,
Makoto Kinouchi,
Nobuyuki Kuribayashi, Go Ohe,
Daisuke Uchida,
Hirokazu Nagai,
Kenji Fujisawa,
Youji Miyamoto
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ABSTRACT: Docetaxel (DOC) and 5-fluorouracil (5-FU) are important anticancer agents widely used in the treatment of a variety of cancers including oral squamous cell carcinoma (OSCC). The purpose of this study was to determine the antitumor efficacy of the sequential administration of DOC and 5-FU against OSCC cells (B88 and CAL27 cells) in vitro and in vivo. In in vitro growth inhibition assays, sequential treatment with DOC followed by 5-FU was more effective in inhibiting cancer cell growth than 5-FU followed by DOC, single treatment with DOC or 5-FU, or combined treatment with DOC and 5-FU. Furthermore, DOC followed by 5-FU significantly inhibited tumor growth in vivo compared to 5-FU followed by DOC. To understand the mechanisms underlying the enhanced growth inhibitory effect of the administration sequence, DOC followed by 5-FU, we examined the expression of 5-FU metabolic enzymes such as thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and orotate phosphoribosyl transferase (OPRT), which were known to regulate the antitumor effect of 5-FU, by real-time RT-PCR and western blot analysis. Downregulation of TS and DPD expression and upregulation of OPRT expression were induced by DOC treatment, suggesting that DOC enhanced the efficacy of 5-FU by altering the expression of its metabolic enzymes. These results indicate that sequential treatment with DOC followed by 5-FU could be a promising therapeutic strategy for oral cancer.
International Journal of Oncology 07/2012; 41(3):1148-56. · 2.40 Impact Factor
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ABSTRACT: The purpose of this study was to evaluate the effectiveness and adverse events of combination chemotherapy with oral S-1 administration following docetaxel (DOC) treatment by superselective intra-arterial infusion as neo-adjuvant chemotherapy (NAC) for patients with oral squamous cell carcinoma. Thirteen patients were enrolled in this study (9 men and 4 women, with a mean age of 61. 0 years). All patients were given S-1 65mg/m(2) per day for 14 days, and DOC 40-50mg/m(2) by intraarterial infusion was administered. The locoregional response evaluated 3 weeks after administration was 100%, including a 69. 2% complete response. According to Oboshi and Shimosato's classification, histological evaluation of surgical specimens revealed that 3 cases were Grade II a, 4 cases Grade II b, 1 case Grade IV a, and 4 cases Grade IV c. The severe side effects were neutropenia and cerebral infarction. The present study suggests that combination chemotherapy with S-1 and DOC by superselective intra-arterial infusion would be an effective and safe regimen in NAC for oral squamous cell carcinomas.
Gan to kagaku ryoho. Cancer & chemotherapy 05/2011; 38(5):777-81.
