Go Ohe

The University of Tokushima, Tokusima, Tokushima, Japan

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Publications (26)75.56 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Salivary gland cancer (SGC) has a comparatively poor prognosis and is prone to frequent recurrence and metastases. Therefore, the development of more effective chemotherapy against SGC is desirable. The aim of the present study was to investigate the antitumour effects of valproic acid (VPA) against SGC in vitro and in vivo. Two human SGC cell lines (HSY and HSG cells) were used in the present study. The effects of VPA on the proliferation of SGC cells in vitro were assessed by MTT assay. Cancer cells treated with VPA were subjected to cell cycle analysis by flow cytometry. In addition, the expression levels of p21 and p27 were examined by real-time RT-PCR to identify the mechanisms of the antitumour effect of VPA on SGC. The effects of VPA on cancer growth in vivo were evaluated in a xenograft model. VPA inhibited the proliferation of SGC cells in a dose-dependent manner in vitro. Degenerated cancer cells were observed at high concentrations of VPA. In the cell cycle analysis, VPA induced cell-growth inhibition and G1 arrest of cell cycle progression in both cancer cell lines in a time- and dose-dependent manner. VPA markedly upregulated the mRNA expression levels of both p21 and p27 in both SGC cell lines in a time-dependent manner. In the xenograft model experiment, VPA treatment markedly inhibited the growth of salivary gland tumours when compared with the growth of the untreated controls. VPA may be a valuable drug in the development of better therapeutic regimens for SGC.
    Oncology Reports 12/2013; · 2.30 Impact Factor
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    ABSTRACT: The streptococcal antitumor agent OK-432 is commonly used as an immunopotentiator for immunotherapy in various types of malignant tumors including oral cancer. It has been demonstrated that OK-432 elicits an antitumor effect by stimulating immunocompetent cells, thereby inducing multiple cytokines including interferon (IFN)-γ, interleukin (IL)-2 and IL-12. Serum concentrations of IFN-γ in patients with oral cancer were examined 24 h after administration of OK-432. Serum concentrations of IFN-γ in patients with advanced cancer were significantly lower than those in patients with early cancer. These results suggested that some soluble factors produced by cancer cells may inhibit IFN-γ production with OK-432. Thus, in the present study, an in vitro simulation model was established for the immune status of patients with oral cancer by adding conditioned medium (CM) derived from oral cancer cell lines into a culture of peripheral blood mononuclear cells (PBMCs) derived from a healthy volunteer. We investigated whether soluble factors derived from oral cancer cells affected IFN-γ production from PBMCs following stimulation with OK-432. PBMCs stimulated with OK-432 produced a large amount of IFN-γ; however, both IFN-γ production and cytotoxic activity from PBMCs induced by OK-432 were inhibited by the addition of CM in a dose-dependent manner. In order to examine these inhibitory effects against IFN-γ production, the contribution of inhibitory cytokines such as IL-4, IL-6, IL-10, transforming growth factor-β and vascular endothelial growth factor was investigated. However, neutralization of these inhibitory cytokines did not recover IFN-γ production inhibited by CM. These results indicated that unknown molecules may inhibit IFN-γ production from PBMCs following stimulation with OK-432.
    Oncology Reports 05/2013; · 2.30 Impact Factor
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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; · 2.66 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; · 3.46 Impact Factor
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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. · 2.66 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.
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    ABSTRACT: The identification of novel stratification biomarkers would benefit the clinical management of patients with salivary gland tumours. Migration-stimulating factor (MSF) is a potent stimulator of cell invasion, matrix remodelling and angiogenesis. The aim of this study was to determine whether MSF was expressed in salivary gland tumours and its potential value as a diagnostic biomarker. Paraffin-embedded archival specimens of small salivary gland tumours were stained with an MSF-specific antibody. The specimens included 27 malignant and seven benign tumours; histologically normal salivary gland adjacent to the tumour was present in 16 specimens. MSF expression was assessed by consensus of 2-4 independent observers according to various indices, including 'overall MSF grade', 'percentage of area stained' and 'intensity of the staining'. The motogenic effect of MSF on a salivary gland tumour cell line, HSG, was examined in the transmembrane assay. Overall MSF expression increased significantly in a step-wise fashion from normal salivary gland to benign and malignant tumours (P = 0.04-0.0001); with moderate/strong positive specimens representing 6%, 33% and 74% of the normal, benign and malignant specimens, respectively. MSF was heterogeneously expressed in both carcinoma and stromal cell compartments, its expression being higher in malignant than benign tumours regarding various MSF indices. In tissue culture studies, exogenous MSF stimulated the migration of HSG cells. These immunohistochemical and functional studies suggest that MSF expression is a potentially useful biomarker of salivary gland tumour progression.
    Journal of Oral Pathology and Medicine 04/2011; 40(10):747-54. · 2.06 Impact Factor
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    ABSTRACT: The protein kinase AKT is activated strongly by many motogenic growth factors, yet has recently been shown capable of inhibiting migration in several cell types. Here we report that treatment with Migration Stimulating Factor (MSF), a truncated form of fibronectin that promotes the migration of many cell types, inhibits AKT activity in human fibroblasts and endothelial cells. In fibroblasts, treatment with either MSF or the AKT inhibitor, Akti-1/2, stimulated migration into 3D collagen gels to a similar extent and the effects of Akti-1/2 on migration could be blocked by the expression of an inhibitor-resistant mutant, AKT1 W80A. These data indicate that MSF promotes fibroblast migration, at least in part, by inhibiting the activity of AKT.
    Cellular signalling 11/2010; 22(11):1655-9. · 4.09 Impact Factor
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    ABSTRACT: To quantify vascularity in periradicular granulomas using different endothelial markers, and assess its value as an index of angiogenesis by comparing granulomas with healthy periodontal ligament (PDL). To use oral tumours, compared with adjacent normal mucosa, as positive controls. Paraffin-embedded sections were stained with antibodies to von Willebrand factor (vWF), a pan-endothelial marker, and CD105, a putative marker for angiogenic vessels. Vascularity was quantified by different methods reflecting vessel volume and density. Irrespective of the marker or method used, vascularity values were similar in periradicular granuloma and PDL. Both tissues were highly vascularized, with levels similar to those found in oral squamous cell carcinoma. Vascularity was significantly higher in the latter than in normal mucosa. Fewer vessels were positive for CD105 than for vWF in the normal mucosa, whereas similar numbers were found in the other tissues examined. A comparison of vascularity in oral tumours and normal oral mucosa provided evidence of angiogenesis in the former. Staining with CD105 added limited value to staining with vWF in these tissues. In contrast, a comparison of periradicular granuloma and PDL failed to demonstrate evidence of angiogenesis in the granuloma. As all vessels were similarly stained with vWF and CD105 in granuloma and PDL, a possible hypothesis is that all vessels are newly formed in these tissues. A more plausible alternative is that CD105 expression may reflect the metabolic activity or intrinsic characteristics of the tissues, rather than the presence of angiogenic vessels.
    International Endodontic Journal 12/2008; 41(11):987-96. · 2.05 Impact Factor
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    ABSTRACT: The role of TSP-1 in tumour growth and angiogenesis remains controversial, with both stimulatory and inhibitory roles proposed. The effects of TSP-1 on the migration of endothelial cells, fibroblast and oral tumour cell lines were examined using the transmembrane assay. TSP-1 induced a bi-phasic effect on human and bovine endothelial cells: stimulation at low concentrations (0.1-10 microg/ml) and inhibition at high concentrations (25-100 microg/ml). FGF-2-stimulated endothelial cell migration was either further stimulated or inhibited by TSP-1, following the same bi-phasic dose response as in the absence of FGF-2. In contrast, TSP-1 stimulated the migration of human fibroblast and oral tumour cells in a dose dependent manner; a plateau was reached with 5-25 microg/ml and no inhibitory effect was observed. These effects were partly neutralised by antibodies to alphavbeta3 integrin. TGF-beta1 (0.1-200 ng/ml tested) mimicked the effects of TSP-1 on cell migration. Function-neutralising antibodies to TGF-beta1 completely abolished both the stimulatory and inhibitory effects of TSP-1 on endothelial migration, but had no effect on TSP-1-stimulated migration of fibroblast and oral tumour cells. The effects of TGF-beta1 were not affected by antibodies to TSP-1. These results indicate that the effects of TSP-1 on endothelial cell migration are mediated by TGF-beta1, whereas the effects on fibroblast and tumour cell migration are TGF-beta1-independent.
    Experimental Cell Research 06/2008; 314(13):2323-33. · 3.56 Impact Factor
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    ABSTRACT: We have previously isolated a lipoteichoic acid (LTA)-related molecule (OK-PSA) from OK-432, a streptococcal agent, by affinity chromatography on a CNBr-activated Sepharose 4B bound TS-2 monoclonal antibody (mAb) that neutralizes the interferon (IFN)-gamma-inducing activity of OK-432. In the current study, we compared the cytokine-inducing and anti-tumor activities of OK-PSA, a TS-2-binding fraction, with those of OK-PTF, a TS-2-unbinding fraction, in order to determine the efficacy of OK-PSA for clinical use in affinity chromatography using TS-2. In the in vitro experiments using human peripheral blood mononuclear cells (PBMCs), OK-PSA markedly induced Th1-type cytokines, while interleukin (IL)-6 and IL-10, Th2-type cytokines, were induced by OK-PTF. Th1-cytokine induction by OK-PTF was not dose-dependent and was suppressed when PBMCs were treated with a high concentration of OK-PTF. In a mouse model, Th1 cytokines were also induced by OK-PSA and Th2 cytokines were induced by OK-PTF. Th2 cytokine-inducing activity of OK-PTF was accelerated in tumor-bearing mice relative to that in healthy mice. Although the anti-tumor effect of OK-PTF was statistically significant, it was much weaker than that of OK-PSA. A significant difference between the anti-tumor effect of OK-PSA and that of OK-PTF was observed (P<0.05). Finally, OK-PSA elicited its cytokine-inducing effect via Toll-like receptor (TLR) 4, whereas OK-PTF-induced signaling was mediated by both TLR2 and TLR4. These findings strongly suggested that the affinity chromatography using TS-2 is a useful strategy to separate the effective component for cancer therapy (OK-PSA) from other components.
    International Immunopharmacology 05/2003; 3(5):643-55. · 2.42 Impact Factor
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    ABSTRACT: The streptococcal agent OK-432 has been used for immunotherapy of head and neck cancer, among other malignancies, but its mechanism of action is unknown. Because the Toll-like receptor 4 (TLR4)/MD-2 complex is important in enabling the mammalian immune system to recognize bacterial components, we investigated whether expression of the TLR4 and MD-2 genes is associated with OK-432-induced anticancer immunity. Peripheral blood mononuclear cells (PBMCs) from 28 patients with head and neck cancer were analyzed for TLR4 and MD-2 mRNA expression by reverse transcription-polymerase chain reaction (RT-PCR) analysis. PBMCs were treated in vitro with OK-432 or with OK-PSA (a lipoteichoic-acid-related molecule that is an active component of OK-432), and interferon-gamma (IFN-gamma) mRNA expression, an immune response measure, was analyzed by RT-PCR. Patient sera collected 24 hours after OK-432 administration were examined for IFN-gamma protein using an enzyme-linked immunosorbent assay. Lewis lung carcinoma-bearing wild-type C57BL/6 and TLR4-deficient mice (four mice per group) received intraperitoneal injections of OK-432, and tumor volumes and sera IFN-gamma levels were measured over time. All statistical tests were two-sided. Twenty patients expressed both TLR4 and MD-2. Expression of TLR4 and MD-2 genes was associated with the in vivo IFN-gamma induction in 19 patients administered OK-432 (Fisher's exact test P<.001). Although both OK-432 and OK-PSA induced IFN-gamma expression from PBMCs in vitro, expression of TLR4 and MD-2 was associated only with IFN-gamma expression induced by OK-PSA (P<.001). In vivo intraperitoneal administration of OK-432 resulted in an increase of IFN-gamma in sera from wild-type mice but not in sera from TLR4-deficient mice. Tumors in wild-type mice treated with OK-432 were statistically significantly smaller than those in mice treated with saline (P =.007). By contrast, in TLR4-deficient mice, there was no difference in tumor volume between the two treatment groups. TLR4 and MD-2 may mediate OK-432-induced anticancer immunity.
    JNCI Journal of the National Cancer Institute 02/2003; 95(4):316-26. · 14.34 Impact Factor
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    ABSTRACT: We have previously isolated a lipoteichoic acid (LTA)-related molecule (OK-PSA) from OK-432, a streptococcal agent, by affinity chromatography on a CNBr-activated Sepharose 4B bound TS-2 monoclonal antibody (mAb) that neutralizes the interferon (IFN)-γ-inducing activity of OK-432. In the current study, we compared the cytokine-inducing and anti-tumor activities of OK-PSA, a TS-2-binding fraction, with those of OK-PTF, a TS-2-unbinding fraction, in order to determine the efficacy of OK-PSA for clinical use in affinity chromatography using TS-2. In the in vitro experiments using human peripheral blood mononuclear cells (PBMCs), OK-PSA markedly induced Th1-type cytokines, while interleukin (IL)-6 and IL-10, Th2-type cytokines, were induced by OK-PTF. Th1-cytokine induction by OK-PTF was not dose-dependent and was suppressed when PBMCs were treated with a high concentration of OK-PTF. In a mouse model, Th1 cytokines were also induced by OK-PSA and Th2 cytokines were induced by OK-PTF. Th2 cytokine-inducing activity of OK-PTF was accelerated in tumor-bearing mice relative to that in healthy mice. Although the anti-tumor effect of OK-PTF was statistically significant, it was much weaker than that of OK-PSA. A significant difference between the anti-tumor effect of OK-PSA and that of OK-PTF was observed (P
    International Immunopharmacology - INT IMMUNOPHARMACOL. 01/2003; 3(5):643-655.
  • Journal of The National Cancer Institute - J NAT CANCER INST. 01/2003; 95(4):316-326.
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    ABSTRACT: We previously generated a monoclonal antibody, TS-2, that neutralizes the interferon (IFN)-gamma-inducing activity of OK-432, a penicillin-killed streptococcal preparation [J. Immunother. 13 (1993) 232]. Expression of the TS-2-binding antigen was markedly higher in the cell wall of the penicillin-treated Streptococcus pyogenes (OK-432) than in the untreated bacteria (Su-BBM). We here isolated the antigens from OK-432 and Su-BBM, designated OK-PSA and Su-PSA, respectively. OK-432 markedly induced IFN-gamma and interleukin (IL)-18 as compared with Su-BBM in human peripheral blood mononuclear cells (PBMC). Furthermore, all of the Thl-type and Th1-inducing cytokines tested [IFN-gamma, tumor necrosis factor (TNF)-alpha, IL-12 and IL-18] were secreted by OK-PSA-stimulated PBMC far better than by Su-PSA-treated PBMC. In addition, the cytolytic activities of the PBMC were accelerated by the stimulation with OK-432 or OK-PSA far better than by the stimulation with Su-BBM or Su-PSA. These findings strongly suggested that OK-PSA is a highly important molecule of OK-432 and may be a useful immunotherapeutic agent for the patients with malignant diseases as a potent Th inducer. It was also shown that penicillin treatment effectively enhances OK-PSA-induced anti-cancer immunity.
    International Immunopharmacology 11/2001; 1(11):1957-68. · 2.42 Impact Factor
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    ABSTRACT: A lipoteichoic acid-related molecule (OK-PSA) isolated from OK-432, a penicillin-killed Streptococcus pyogenes, is a potent inducer of Th1 cytokines, and elicits anti-cancer effect in tumor-bearing mice. Toll-like receptor (TLR) 4 is a member of the recently identified toll-like receptor family of proteins that has been implicated in lipopolysaccharide-induced cell signaling. In the present study, we have examined the role of TLR4 for OK-PSA-induced Th1-cytokine production and anti-tumor effect by using C3H/HeJ mice in which TLR4 function is impaired. Although OK-PSA strikingly induced Th1 cytokines [interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-2, IL-12 and IL-18] in the splenocytes derived from control animals (C3H/HeN), OK-PSA did not induce the cytokines in the splenocytes from C3H/HeJ. Furthermore, C3H/HeJ-derived splenocytes acquired the responsiveness to OK-PSA stimulation by overexpression of TLR4 gene. Finally, OK-PSA administration significantly inhibited the tumor growth and lung metastasis of syngeneic squamous cell carcinoma cells in C3H/HeN; however, no effect of OK-PSA was observed in C3H/HeJ. These findings strongly suggest that TLR4 signaling is involved in regulating OK-PSA-induced anti-cancer immunity.
    International Immunopharmacology 10/2001; 1(9-10):1789-95. · 2.42 Impact Factor
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    ABSTRACT: We isolated the lipoteichoic-acid-related molecule (OK-PSA) from OK-432, a streptococcal preparation, by affinity chromatography on CNBr-activated Sepharose-4B-bound monoclonal antibody TS-2, which neutralizes the interferon (IFN)-&#37-inducing activity of OK-432. We have previously reported that OK-PSA is a potent inducer of Th1-type cytokines in human peripheral blood mononuclear cells in vitro. In this study, we conducted an animal experiment to examine whether OK-PSA exhibits an anti-tumor effect in vivo by acting as a Th1 inducer in syngeneic Meth-A tumor-bearing BALB/c mice, in which the Th2 response is genetically dominant. It was found that OK-PSA induced Th1-type cytokines [IFN-&#37, tumor necrosis factor-&#33, interleukin (IL)-2, IL-12 and IL-18] in BALB/c mice bearing Meth-A tumor and caused a marked anti-tumor effect. Although it was suggested by an in vitro study, using spleen cells derived from the animals, that IL-18 plays the greatest role in the induction of the Th1-dominant state and tumor cell killing induced by OK-PSA, the in vivo experiments demonstrated that both IL-12 and IL-18 are essential in the anti-tumor effect exhibited by OK-PSA. These findings strongly suggest that OK-PSA is a major effector molecule of OK-432 and may be a useful immunotherapeutic agent, as a potent Th1 inducer, for cancer patients with a Th2-dominant state.
    Cancer Immunology and Immunotherapy 09/2001; 50(8):408-416. · 3.64 Impact Factor
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    ABSTRACT:  We have isolated a 55 kDa protein from the seed extract of Aeginetia indica L. (AIL), a parasitic plant, by affinity chromatography on an N-hydroxysuccinimide-activated Sepharose High Performance column bound with F3, a monoclonal antibody that neutralizes the cytokine-inducing and anti-tumor effect of AIL. In the present study, we examined this protein (AILb-A) for cytokine induction and anti-tumor effects by animal study, using syngeneic Meth-A tumor-bearing BALB/c mice, in which the Th2 response is genetically dominant. AILb-A administration resulted in markedly increased levels of Th1 cytokines [interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-12 and IL-18] in the sera derived from Meth-A-bearing mice. The in vitro re-stimulation with AILb-A of splenocytes derived from AILb-A-primed mice also selectively induced Th1-type cytokines and antigen-specific killer cell activity. The neutralizing test using cytokine-specific antibodies revealed that AILb-A-induced IL-18 plays a most significant role for IFN-γ- and killer cell-inducing activities. Furthermore, IL-12 and IL-18 induced by AILb-A inhibited specifically IL-10 and IL-4 production, respectively. Finally, we examined the anti-tumor effect of AILb-A in both Meth-A-bearing BALB/c mice and Meth-A-bearing nude mice with BALB/c background. AILb-A exhibited a striking anti-tumor effect in normal BALB/c mice inoculated with Meth-A cells. In athymic nude mice, the anti-tumor effect of AILb-A was relatively weak. These findings strongly suggested that AILb-A is a potent Th1 inducer and may be a useful immunotherapeutic agent for patients with malignant diseases.
    Cancer Immunology and Immunotherapy 01/2001; 50(5):251-259. · 3.64 Impact Factor
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    ABSTRACT: Osteoclastic bone resorption is an important step in bone invasion in several malignancies. Although interleukin (IL)-6 accelerates osteoclastic bone resorption, it remains unclear whether IL-6 may be involved in bone invasion of oral cancer. The pit formation assay with calf femur-derived bone slices was performed to examine the bone-resorbing activity of osteoclasts and cancer cells. The chemotaxis activity of the culture media was analyzed by the use of Boyden chamber technique. Nude mice, which were inoculated with IL-6-producing oral cancer cells into masseter, were treated with anti-IL-6 neutralizing antibody, and mandibular-bone invasion of the cells was assessed. BHY, a bone-invasive oral cancer cell line, but not HNT, a noninvasive cell line, produced large amounts of IL-6. In a pit formation assay, addition of conditioned medium (CM) derived from BHY but not HNT increased osteoclastic bone resorption, and the effects were inhibited by anti-IL-6 antibody. BHY-secreted IL-6 showed significant chemotaxis activity for osteoclasts. Of note, CM from the cocultivation of osteoclasts and BHY markedly enhanced the cancer cell migration, and the chemotaxis activity was significantly reduced when anti-IL-6 antibody was added into the coculture and then CM were collected, but not when the antibody was added into the CM after they were collected. Furthermore, treatment with anti-IL-6 antibody almost completely inhibited mandibular bone invasion of BHY in nude mice. These results strongly suggest that IL-6 secreted by oral cancer cells plays a significant role in bone invasion.
    Cancer 12/2000; 89(9):1966-75. · 5.20 Impact Factor
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    ABSTRACT: We have isolated the lipoteichoic acid (LTA)-related molecule (OK-PSA) from OK-432, a streptococcal preparation, by an affinity chromatography on CNBr-activated Sepharose 4B-bound TS-2 monoclonal antibody (mAb) that neutralizes interferon (IFN)-γ-inducing activity of OK-432. In in vitro experiments using human peripheral blood mononuclear cells (PBMC), OK-PSA induced IFN-γ, interleukin (IL)-2, IL-12, IL-18, tumor necrosis factor (TNF)-α and TNF-β that are generally called “Th1-type cytokines” both in protein and in mRNA levels. Furthermore, the neutralizing test using cytokine-specific antibodies demonstrated that IL-18 plays a most significant role for IFN-γ- and killer cell-inducing ability of OK-PSA among the other cytokines tested. These findings clearly indicated that OK-PSA, an LTA-related molecule, is a main effective component of OK-432, and is a potent inducer of Th1-type cytokines by T cell and natural killer (NK) cell activation mediated by monocytes-derived IL-18, and that it may be a useful immunotherapeutic agent for the patients with malignancies better than original OK-432.
    Immunopharmacology 10/2000;