研究者業績

齋藤 謙悟

サイトウ ケンゴ  (Kengo Saito)

基本情報

所属
千葉大学 大学院医学研究院 講師

J-GLOBAL ID
200901016344773817
researchmap会員ID
5000048233

学歴

 2

論文

 58
  • Hidetoshi Igari, Seiichiro Sakao, Takayuki Ishige, Kengo Saito, Shota Murata, Misuzu Yahaba, Toshibumi Taniguchi, Akiko Suganami, Kazuyuki Matsushita, Yutaka Tamura, Takuji Suzuki, Eiji Ido
    Nature communications 15(1) 3604-3604 2024年4月29日  
    Numerous SARS-CoV-2 variant strains with altered characteristics have emerged since the onset of the COVID-19 pandemic. Remdesivir (RDV), a ribonucleotide analogue inhibitor of viral RNA polymerase, has become a valuable therapeutic agent. However, immunosuppressed hosts may respond inadequately to RDV and develop chronic persistent infections. A patient with respiratory failure caused by interstitial pneumonia, who had undergone transplantation of the left lung, developed COVID-19 caused by Omicron BA.5 strain with persistent chronic viral shedding, showing viral fusogenicity. Genome-wide sequencing analyses revealed the occurrence of several viral mutations after RDV treatment, followed by dynamic changes in the viral populations. The C799F mutation in nsp12 was found to play a pivotal role in conferring RDV resistance, preventing RDV-triphosphate from entering the active site of RNA-dependent RNA polymerase. The occurrence of diverse mutations is a characteristic of SARS-CoV-2, which mutates frequently. Herein, we describe the clinical case of an immunosuppressed host in whom inadequate treatment resulted in highly diverse SARS-CoV-2 mutations that threatened the patient's health due to the development of drug-resistant variants.
  • XUE MA, TOMOKO OGAWA, ZHENG TIAN, RUIRONG YI, KANG TANG, KENGO SAITO, SARA YATABE, YOSHIFUMI OHNO, RYOSUKE MUROYAMA, EIJI IDO, HISAHIRO MATSUBARA, HIROSHI SHIRASAWA
    Anticancer Research 43(7) 2923-2932 2023年6月23日  
  • Kenta Shinoda, Akiko Suganami, Yasumitsu Moriya, Masamichi Yamashita, Tsutomu Tanaka, Akane S Suzuki, Hiroshi Suito, Yasunori Akutsu, Kengo Saito, Yoko Shinozaki, Kazuoki Isojima, Naohito Nakamura, Yasushi Miyauchi, Hiroshi Shirasawa, Hisahiro Matsubara, Yoshiharu Okamoto, Toshinori Nakayama, Yutaka Tamura
    Photodiagnosis and photodynamic therapy 39 103041-103041 2022年9月  
    BACKGROUND: Phototheranostics represents a highly promising paradigm for cancer therapy, although selecting an appropriate optical imager and sensitizer for clinical use remains challenging. METHODS: Liposomally formulated phospholipid-conjugated indocyanine green, denoted as LP-iDOPE, was developed as phototheranostic nanoparticle and its cancer imaging-mediated photodynamic reaction, defined as the immune response induced by photodynamic and photothermal effects, was evaluated with a near-infrared (NIR)-light emitting diode (LED) light irradiator. RESULTS: Using in vivo NIR fluorescence imaging, we demonstrated that LP-iDOPE was selectively delivered to tumor sites with high accumulation and a long half-life. Following low-intensity NIR-LED light irradiation on the tumor region of LP-iDOPE accumulated, effector CD8+ T cells were activated at the secondary lymphoid organs, migrated, and subsequently released cytokines including interferon-γ and tumor necrosis factor-α, resulting in effective tumor regression. CONCLUSIONS: Our anti-cancer strategy based on tumor-specific LP-iDOPE accumulation and low-intensity NIR-LED light irradiation to the tumor regions, i.e., photodynamic reaction, represents a promising approach to noninvasive cancer therapy.
  • Mari Komatsu, Kengo Saito, Isao Miyamoto, Kazuyuki Koike, Manabu Iyoda, Dai Nakashima, Atsushi Kasamatsu, Masashi Shiiba, Hideki Tanzawa, Katsuhiro Uzawa
    Oncology Letters 23(2) 2021年12月14日  
  • 駒 綾香, 小松 万理, 斎藤 謙悟, 坂本 洋右, 伊豫田 学, 中嶋 大, 笠松 厚志, 椎葉 正史, 鵜澤 一弘, 丹沢 秀樹
    日本口腔診断学会雑誌 34(1) 88-88 2021年2月  
  • Yoshifumi Ohno, Ruirong Yi, Akiko Suganami, Yutaka Tamura, Akio Matsumoto, Shoji Matsumoto, Kengo Saito, Hiroshi Shirasawa
    Anticancer research 41(2) 699-706 2021年2月  
    BACKGROUND/AIM: Benzimidazoles are considered potential anticancer candidates. We herein studied the anticancer activity of CCL299, 4-(1H-1,3-benzodiazol-1-yl) benzonitrile. MATERIALS AND METHODS: In this in vitro study, we used ATP assays, flow cytometry, western blotting, and caspase-3/7 assays to evaluate the effects of CCL299 on cell proliferation, cell-cycle progression and apoptosis. RESULTS: ATP assays showed that CCL299 inhibited cell growth in the hepatoblastoma cell line HepG2 and the cervical cancer cell line HEp-2, without exhibiting cytotoxic effects on non-cancer cells and TIG-1-20 fibroblasts. Flow cytometry, western blotting, and caspase-3/7 assays revealed that CCL299 induced G1-phase cell-cycle arrest followed by apoptosis that was associated with up-regulation of p-p53 (Ser15) and p21 expression and the down-regulation of p-CDK2 (Thr160) expression. CONCLUSION: CCL299 exhibits cytotoxic activity via apoptosis in a subset of cancer cells, and should be considered as a promising anticancer candidate agent.
  • 駒 綾香, 小松 万理, 斎藤 謙悟, 坂本 洋右, 伊豫田 学, 中嶋 大, 笠松 厚志, 椎葉 正史, 鵜澤 一弘, 丹沢 秀樹
    日本口腔内科学会雑誌 26(2) 136-136 2020年12月  
  • Ruirong Yi, Yoshifumi Ohno, Zheng Tian, Shuhan Guo, Weiwei Chen, Xue Ma, Nan Win, Qisen Li, Majid Vahed, Kengo Saito, Shingo Nakamoto, Akiko Suganami, Naohisa Isegawa, Keisuke Yoshida, Shinji Harada, Yutaka Tamura, Atsushi Nishida, Hiroshi Shirasawa
    Oncology Reports 44(6) 2770-2782 2020年10月13日  
  • Eriko Y. Saito, Kengo Saito, Tomoro Hishiki, Ayako Takenouchi, Takeshi Saito, Yoshiharu Sato, Keita Terui, Tadashi Matsunaga, Hiroshi Shirasawa, Hideo Yoshida
    Pediatric Surgery International 36(10) 1173-1180 2020年10月1日  
    Purpose: Oncolytic viral therapy for neuroblastoma (NB) cells with Sindbis virus (SINV) is a promising strategy for treating high-risk NB. Here, we evaluated the possibility of using SINV structural proteins as therapeutic agents for NB since UV-inactivated SINV could induce cytopathogenic effects. Methods: The cytotoxicity of UV-inactivated SINV toward human NB cell lines NB69, NGP, GOTO, NLF, SK-N-SH, SH-SY5Y, CHP134, NB-1, IMR32, and RT-BM-1 were analyzed. Apoptosis was confirmed by TUNEL assays. To determine the components of SINV responsible for the cytotoxicity of UV-inactivated SINV, expression vectors encoding the structural proteins, namely capsid, E2, and E1, were transfected in NB cells. Cytotoxicity was evaluated by MTT assays. Results: UV-inactivated SINV elicited more significant cytotoxicity in NB69, NGP, and RT-BM-1 than in normal human fibroblasts. Results of the transfection experiments showed that all NB cell lines susceptible to UV-inactivated SINV were highly susceptible to the E1 protein, whereas fibroblasts transfected with vectors harboring capsid, E1, or E2 were not. Conclusions: We demonstrated that the cytotoxicity of the UV-inactivated SINV is due to apoptosis induced by the E1 structural protein of SINV, which can be used selectively as a therapeutic agent for NB.
  • Eriko Y Saito, Kengo Saito, Tomoro Hishiki, Ayako Takenouchi, Takeshi Saito, Yoshiharu Sato, Keita Terui, Tadashi Matsunaga, Hiroshi Shirasawa, Hideo Yoshida
    Pediatric surgery international 36(10) 1173-1180 2020年10月  
    PURPOSE: Oncolytic viral therapy for neuroblastoma (NB) cells with Sindbis virus (SINV) is a promising strategy for treating high-risk NB. Here, we evaluated the possibility of using SINV structural proteins as therapeutic agents for NB since UV-inactivated SINV could induce cytopathogenic effects. METHODS: The cytotoxicity of UV-inactivated SINV toward human NB cell lines NB69, NGP, GOTO, NLF, SK-N-SH, SH-SY5Y, CHP134, NB-1, IMR32, and RT-BM-1 were analyzed. Apoptosis was confirmed by TUNEL assays. To determine the components of SINV responsible for the cytotoxicity of UV-inactivated SINV, expression vectors encoding the structural proteins, namely capsid, E2, and E1, were transfected in NB cells. Cytotoxicity was evaluated by MTT assays. RESULTS: UV-inactivated SINV elicited more significant cytotoxicity in NB69, NGP, and RT-BM-1 than in normal human fibroblasts. Results of the transfection experiments showed that all NB cell lines susceptible to UV-inactivated SINV were highly susceptible to the E1 protein, whereas fibroblasts transfected with vectors harboring capsid, E1, or E2 were not. CONCLUSIONS: We demonstrated that the cytotoxicity of the UV-inactivated SINV is due to apoptosis induced by the E1 structural protein of SINV, which can be used selectively as a therapeutic agent for NB.
  • Ayumi Yamamoto, Masashi Shiiba, Shusaku Yoshimura, Yasuhiro Saito, Kengo Saito, Yosuke Sakamoto, Hideki Tanzawa, Katsuhiro Uzawa
    Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology 32(5) 380-386 2020年9月1日  
    The main symptom of Kimura disease (KD), a rare, chronic inflammatory disorder of unknown etiology, is painless granulation preferentially developing in the head and neck region's soft tissues, especially in the parotid and submandibular glands and neck lymph nodes. KD is characterized clinically by peripheral blood eosinophilia and elevated serum immunoglobulin E (IgE) levels and histopathologically by high capillary vascularization and lymphoid follicle formation with eosinophil infiltration in the connective tissues. Angiolymphoid hyperplasia with eosinophilia (ALHE), a rare benign tumor of unknown etiology, also occurs in the head and neck frequently as single/multiple angiomatous papules/nodules varying from light brown to pink. Histopathologically, accelerated endothelial cell proliferation and high lymphocyte and eosinophil infiltration are observed. Due to KD's and ALHE's similar clinical and pathological symptoms, differential diagnosis is challenging. Their manifestations include a painless head/neck subcutaneous swelling. Here, we have described a case involving a 44-year-old man who presented with an upper lip mass that increased in size for 1 year. Laboratory studies revealed leukocytosis and eosinophilia. Computed tomography and magnetic resonance imaging examinations revealed a submucosal lip mass. Suspect minor salivary gland malignancies and lymphomas were surgically excised. Histopathologically, we observed marked lymphoid follicle proliferation with inflammatory cell, including eosinophil infiltration, capillary proliferation, and a developed vessel not normally present in the lip. Because differentiating between KD and ALHE is difficult, clinical differentiation was our focus. The Asian male patient with lymphadenopathy, eosinophilia, and high IgE levels was finally diagnosed with KD that has not recurred in 1 year.
  • Masashi Shiiba, Hitomi Yamagami, Tadashi Sudo, Yosuke Tomokuni, Daisuke Kashiwabara, Tadaaki Kirita, Jingo Kusukawa, Masamichi Komiya, Kanchu Tei, Yoshimasa Kitagawa, Yutaka Imai, Hitoshi Kawamata, Hiroki Bukawa, Kazuhito Satomura, Hidero Oki, Keiji Shinozuka, Kazumasa Sugihara, Tsuyoshi Sugiura, Joji Sekine, Hidetaka Yokoe, Kengo Saito, Hideki Tanzawa
    Heliyon 6(8) 2020年8月  
    S-1 is an anticancer agent that is comprised of tegafur, gimeracil, and oteracil potassium, and is widely used in various carcinomas including oral squamous cell carcinoma (OSCC). Although an established prediction tool is not available, we aimed to develop prediction models for the sensitivity of primary OSCC cases to the preoperative administration of S-1. We performed DNA microarray analysis of 95 cases with OSCC. Using global gene expression data and the clinical data, we developed two different prediction models, namely, model 1 that comprised the complete response (CR) + the partial response (PR) versus stable disease (SD) + progressive disease (PD), and model 2 that comprised responders versus non-responders. Twelve and 18 genes were designated as feature genes (FGs) in models 1 and 2, respectively, and, of these, six genes were common to both models. The sensitivity was 96.3%, the specificity was 91.2%, and the accuracy was 92.6% for model 1, and the sensitivity was 95.6%, the specificity was 85.2%, and the accuracy was 92.6% for model 2. These models were validated using receiver operating characteristic analysis, and the areas under the curves were 0.967 and 0.949 in models 1 and 2, respectively. The data led to the development of models that can reliably predict the sensitivity of patients with OSCC to the preoperative administration of S-1. The mechanism that regulates S-1 sensitivity remains unclear; however, the prediction models developed provide hope that further functional investigations into the FGs will lead to a greater understanding of drug resistance.
  • Shuhan Guo, Yoshifumi Ohno, Ayumu Tsubosaka, Majid Vahed, Ruirong Yi, Xue Ma, Qisen Li, Kengo Saito, Shingo Nakamoto, Ryosuke Muroyama, Akiko Suganami, Yutaka Tamura, Akiko Tsuchida, Takayoshi Arai, Hiroshi Shirasawa
    American Journal of Medical and Clinical Sciences 5(1) 2020年6月30日  
  • 喜田 晶洋, 椎葉 正史, 皆川 康之, 小池 一幸, 山野 由紀男, 伏見 一章, 伊豫田 学, 齋藤 謙悟, 鵜澤 一弘, 丹沢 秀樹
    日本口腔外科学会雑誌 66(3) 124-130 2020年3月  
    口腔扁平上皮癌は高齢者に多く発生し、年齢や内科的疾患を理由に手術不適応となる場合も多い。今回、手術不適応の患者にサイパーナイフ治療を行った32例(初発20例、再発12例)の成績を報告した。完全奏効(CR)が16例、部分奏効(PR)が7例、安定(SD)が3例、増悪(PD)が6例であり、初発例ではCRが12例、PRが3例、SDが2例、PDが3例、再発例ではCRが4例、PRが4例、SDが1例、PDが3例であった。奏効(CR+PR)率は全体で72%、初発例で75%、再発例で67%であった。早期有害事象を25例(78%)、晩期有害事象を6例(19%)に認めた。早期有害事象は口内炎が主症状であり、Grade 2までの事象であった。晩期有害事象の内訳は放射線性骨髄炎5例、皮膚瘻孔1例であった。治療効果に影響している因子を明らかにするため、「性別」「年齢」「PS分類」「原発部位」「病理組織型」「TNM分類」「Stage分類」「照射時期」「PTV」などについて多変量解析を行った結果、有意な因子として「T分類」「Stage分類」「照射時期」「PTV」が抽出された。
  • 大野 吉史, 蟻 瑞栄, 陳 偉巍, 田 錚, 郭 書翰, 馬 雪, 菅波 晃子, 齋藤 謙悟, 田村 裕, 松本 明郎, 白澤 浩
    日本化学療法学会雑誌 64(Suppl.A) 204-204 2016年5月  査読有り
  • Higashi K, Mibu F, Saito K, Limwikrant W, Yamamoto K, Moribe K
    Eur J Pharm Sci. 99 24-31 2016年  査読有り
  • Ayako Takenouchi, Kengo Saito, Eriko Saito, Takeshi Saito, Tomoro Hishiki, Tadashi Matsunaga, Naohisa Isegawa, Hideo Yoshida, Naomi Ohnuma, Hiroshi Shirasawa
    PEDIATRIC SURGERY INTERNATIONAL 31(12) 1151-1159 2015年12月  査読有り
    With current treatment regimens, high-risk neuroblastoma (NB) remains largely incurable. Oncolytic viral therapy uses replication-competent viruses, like Sindbis virus (SINV), to kill cancers. The SINV AR339 strain is blood borne and relatively non-virulent. We evaluated the feasibility of SINV AR339 for treating human NB. The cytotoxicity and viral growth of SINV AR339 were evaluated for five human NB cell lines, SK-N-SH, IMR-32, LAN-5, GOTO, and RT-BM-1. SINV-induced apoptosis was confirmed by TUNEL assays and PARP-1 cleavage. In vivo effects of SINV on neuroblastoma cell xenografts in nude mice were assessed by intratumoral or intravenous SINV inoculation. In five human NB cell lines, SINV infections induced remarkable cytotoxicity. The mRNA expressions of anti-apoptotic genes, Bcl-2 and Bcl-xL, in LAN-5 and RT-BM-1, which were less sensitive to SINV infection, increased in response to SINV infection, while the other NB cell lines sensitive to SINV infection failed to respond. In nude mice, intratumoral and intravenous SINV inoculations caused significant regression of NB xenograft tumors. Our results suggested that SINV AR339 was significantly oncolytic against human NB. Thus, SINV showed promise as a novel therapy for treating NB.
  • Isao Miyamoto, Atsushi Kasamatsu, Masanobu Yamatoji, Dai Nakashima, Kengo Saito, Morihiro Higo, Yosuke Endo-Sakamoto, Masashi Shiiba, Hideki Tanzawa, Katsuhiro Uzawa
    Biochemistry and Biophysics Reports 3 26-31 2015年9月1日  査読有り
    Kinesin family member 14 (KIF14), a microtubule-based motor protein, plays an important role in chromosomal segregation, congression, and alignment. Considerable evidence indicates that KIF14 is involved in cytokinesis, although little is known about its role in oral squamous cell carcinomas (OSCCs). In the current study, we functionally and clinically investigated KIF14 expression in patients with OSCC. Quantitative reverse transcriptase-polymerase chain reaction and immunoblotting analyses were used to assess the KIF14 regulatory mechanism in OSCC. Immunohistochemistry (IHC) was performed to analyze the correlation between KIF14 expression and clinical behavior in 104 patients with OSCC. A KIF14 knockdown model of OSCC cells (shKIF14 cells) was used for functional experiments. KIF14 expression was up-regulated significantly (. P&lt 0.05) in OSCCs compared with normal counterparts in vitro and in vivo. In addition, shKIF14 cells inhibited cellular proliferation compared with control cells by cell-cycle arrest at the G2/M phase through up-regulation of G2 arrest-related proteins (p-Cdc2 and cyclin B1). As expected, IHC data from primary OSCCs showed that KIF14-positive patients exhibited significantly (. P&lt 0.05) more larger tumors compared with KIF14-negative patients. The current results suggest for the first time that KIF14 is an indicator of tumoral size in OSCCs and that KIF14 might be a potential therapeutic target for development of new treatments for OSCCs.
  • Tomoaki Saito, Atsushi Kasamatsu, Katsunori Ogawara, Isao Miyamoto, Kengo Saito, Manabu Lyoda, Takane Suzuki, Yosuke Endo-Sakamoto, Masashi Shiiba, Hideki Tanzawa, Katsuhiro Uzawa
    PLOS ONE 10(9) e0137923 2015年9月  査読有り
    Background Semaphorins (SEMAs) consist of a large family of secreted and membrane-anchored proteins that are important in neuronal pathfinding and axon guidance in selected areas of the developing nervous system. Of them, SEMA7A has been reported to have a chemotactic activity in neurogenesis and to be an immunomodulator; however, little is known about the relevance of SEMA7A in the behaviors of oral squamous cell carcinoma (OSCC). Methods We evaluated SEMA7A expression in OSCC-derived cell lines and primary OSCC samples using quantitative reverse transcriptase-polymerase chain reaction, immunoblotting, and semiquantitative immunohistochemistry (sq-IHC). In addition, SEMA7A knockdown cells (5hSEMA7A cells) were used for functional experiments, including cellular proliferation, invasiveness, and migration assays. We also analyzed the clinical correlation between SEMA7A status and clinical behaviors in patients with OSCC. Results SEMA7A mRNA and protein were up-regulated significantly (P<0.05) in OSCC-derived cell lines compared with human normal oral keratinocytes. The shSEMA7A cells showed decreased cellular growth by cell-cycle arrest at the G1 phase, resulting from up-regulation of cyclin-dependent kinase inhibitors (p21c1P1 and p27KiP1) and down-regulation of cyclins (cyclin Dl, cyclin E) and cyclin-dependent kinases (CDK2, CDK4, and CDK6); and decreased invasiveness and migration activities by reduced secretion of matrix metalloproteases (MMPs) (MMP-2, proMMP-2, pro-MMP-9), and expression of membrane type 1MMP (MT1-MMP). We also found inactivation of the extracellular regulated kinase 1/2 and AKT pathways, an upstream molecule of cell-cycle arrest at the G1 phase, and reduced secretion of MMPs in shSEMA7A cells. sq-IHC showed that SEMA7A expression in the primary OSCCs was significantly (P = 0.001) greater than that in normal counterparts and was correlated with primary tumoral size (P = 0.0254) and regional lymph node metastasis (P = 0.0002). Conclusion Our data provide evidence for an essential role of SEMA7A in tumoral growth and metastasis in OSCC and indicated that SEMA7A may play a potential diagnostic/therapeutic target for use in patients with OSCC.
  • Ruirong Yi, Kengo Saito, Naohisa Isegawa, Hiroshi Shirasawa
    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 462(4) 426-432 2015年7月  査読有り
    We examined the impact of Sindbis virus (SINV) infection on cell cycle progression in a cancer cell line, HeLa, and a non-cancerous cell line, Vero. Cell cycle analyses showed that SINV infection is able to alter the cell cycle progression in both HeLa and Vero cells, but differently, especially during the early stage of infection. SINV infection affected the expression of several cell cycle regulators (CDK4, CDK6, cyclin E, p21, cyclin A and cyclin B) in HeLa cells and caused HeLa cells to accumulate in S phase during the early stage of infection. Monitoring SINV replication in HeLa and Vero cells expressing cell cycle indicators revealed that SINV which infected HeLa cells during G(1) phase preferred to proliferate during S/G(2) phase, and the average time interval for viral replication was significantly shorter in both HeLa and Vero cells infected during G(1) phase than in cells infected during S/G(2) phase. (C) 2015 The Authors. Published by Elsevier Inc.
  • Masashi Shiiba, Kengo Saito, Hitomi Yamagami, Dai Nakashima, Morihiro Higo, Atsushi Kasamatsu, Yosuke Sakamoto, Katsunori Ogawara, Katsuhiro Uzawa, Yuichi Takiguchi, Hideki Tanzawa
    INTERNATIONAL JOURNAL OF ONCOLOGY 46(5) 1978-1984 2015年5月  査読有り
    Inflammatory abnormalities have been implicated in the pathogenesis of various human diseases, including cancer. Interleukin-1 receptor antagonist (IL1RN) is a potent anti-inflammatory molecule that modulates the biological activity of the proinflammatory cytokine, interleukin-1. The aim of this study was to examine the expression of IL1RN in oral squamous cell carcinomas (OSCCs), and to determine its clinical significance. Expression levels of IL1RN in matched normal and tumor specimens from 39 OSCCs were evaluated using real-time quantitative polymerase chain reaction methods, and immunohistochemical analysis. Protein expression of IL1RN was also examined in 18 oral premalignant lesions (OPLs). Expression of IL1RN mRNA was significantly downregulated in OSCCs compared with normal tissues. Decreased expression of IL1RN protein was also observed in OPLs and OSCCs. The IL1RN expression level was lower in the OPL cases with severe dysplasia compared to those with mild/moderate dysplasia. Significantly downregulated IL1RN expression was observed in all OSCC lesion sites examined when compared with the matched normal tissues. However, the decreased level of IL1RN expression did not correspond with tumor progression. Noteworthy, IL1RN expression was higher in the advanced OSCC cases (T3/T4) compared to early cases (T1/T2). Among OSCC samples, relatively higher IL1RN expression was associated with active tumor development in the OSCCs occurring in the buccal mucosa, oral floor, fauces and gingiva, but not the tongue. These data suggest that IL1RN may exhibit opposing characteristics in oral malignancies depending on the stage of cancer development, suppressing early carcinogenic events, yet promoting tumor development in some lesion sites. Thus, IL1RN could represent a reliable biomarker for the early diagnosis of OSCCs. Furthermore, IL1RN may possess unknown and complex functions in the developed OSCC.
  • Xia Jiang, Tatsuo Kanda, Shingo Nakamoto, Kengo Saito, Masato Nakamura, Shuang Wu, Yuki Haga, Reina Sasaki, Naoya Sakamoto, Hiroshi Shirasawa, Hiroaki Okamoto, Osamu Yokosuka
    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS 458(4) 908-912 2015年3月  査読有り
    The JAK2 inhibitor AZD1480 has been reported to inhibit La protein expression. We previously demonstrated that the inhibition of La expression could inhibit hepatitis A virus (HAV) internal ribosomal entry-site (IRES)-mediated translation and HAV replication in vitro. In this study, we analyzed the effects of AZD1480 on HAV IRES-mediated translation and replication. HAV IRES-mediated translation in COS7-HAV-IRES cells was inhibited by 0.1-1 mu M AZD1480, a dosage that did not affect cell viability. Results showed a significant reduction in intracellular HAV HA11-1299 genotype IIIA RNA levels in Huh7 cells treated with AZD1480. Furthermore, AZD1480 inhibited the expression of phosphorylated-(Tyr-705)-signal transducer and activator of transcription 3 (STAT3) and La in Huh7 cells. Therefore, we propose that AZD1480 can inhibit HAV IRES activity and HAV replication through the inhibition of the La protein. (C) 2015 Elsevier Inc. All rights reserved.
  • Takenouchi A, Saito K, Saito E, Saito T, Shirasawa H
    Pediatr Surg Int. 31(4) 426-432 2015年  査読有り
  • Shingo Nakamoto, Tatsuo Kanda, Chiaki Nakaseko, Emiko Sakaida, Chikako Ohwada, Masahiro Takeuchi, Yusuke Takeda, Naoya Mimura, Tohru Iseki, Shuang Wu, Makoto Arai, Fumio Imazeki, Kengo Saito, Hiroshi Shirasawa, Osamu Yokosuka
    INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES 15(11) 21455-21467 2014年11月  査読有り
    We retrospectively reviewed 413 recipients with hematologic malignancies who underwent hematopoietic stem cell transplantation (HSCT) between June 1986 and March 2013. Recipients with antibody to hepatitis B core antigen (anti-HBc) and/or to hepatitis B surface antigen (anti-HBs) were regarded as experiencing previous hepatitis B virus (HBV) infection. Clinical data of these recipients were reviewed from medical records. We defined >= 1 log IU/mL increase in serum HBV DNA from nadir as HBV reactivation in hepatitis B surface antigen (HBsAg)-positive recipients, and also defined >= 1 log IU/mL increase or re-appearance of HBV DNA and/or HBsAg as HBV reactivation in HBsAg-negative recipients. In 5 HBsAg-positive recipients, 2 recipients initially not administered with nucleos(t) ide analogues (NUCs) experienced HBV reactivation, but finally all 5 were successfully controlled with NUCs. HBV reactivation was observed in 11 (2.7%) of 408 HBsAg-negative recipients; 8 of these were treated with NUCs, and fortunately none developed acute liver failure. In 5 (6.0%) of 83 anti-HBc and/or anti-HBs-positive recipients, HBV reactivation occurred. None of 157 (0%) recipients without HBsAg, anti-HBs or anti-HBc experienced HBV reactivation. In HSCT recipients, HBV reactivation is a common event in HBsAg-positive recipients, or in HBsAg-negative recipients with anti-HBc and/or anti-HBs. Further attention should be paid to HSCT recipients with previous exposure to HBV.
  • Xia Jiang, Tatsuo Kanda, Shuang Wu, Shingo Nakamoto, Kengo Saito, Hiroshi Shirasawa, Tomoko Kiyohara, Koji Ishii, Takaji Wakita, Hiroaki Okamoto, Osamu Yokosuka
    PLOS ONE 9(7) e101993 2014年7月  査読有り
    Background: Despite the development and availability of hepatitis A virus (HAV) vaccine, HAV infection is still a major cause of acute hepatitis that occasionally leads to fatal liver disease. HAV internal ribosomal entry-site (IRES) is one of the attractive targets of antiviral agents against HAV. The aim of the present study is to evaluate the impact of La, one of the cellular proteins, on HAV IRES-mediated translation and HAV replication. Methods and Findings: We investigated the therapeutic feasibility of siRNAs specific for cellular cofactors for HAV IRES-mediated translation in cell culture. It was revealed that siRNA against La could inhibit HAV IRES activities as well as HAV subgenomic replication. We also found that the Janus kinase (JAK) inhibitors SD-1029 and AG490, which reduce La expression, could inhibit HAV IRES activities as well as HAV replication. Conclusions: Inhibition of La by siRNAs and chemical agents could lead to the efficient inhibition of HAV IRES-mediated translation and HAV replication in cell culture models. La might play important roles in HAV replication and is being exploited as one of the therapeutic targets of host-targeting antivirals.
  • Kohji Mori, Yukinao Hayashi, Tetsuya Akiba, Miyuki Nagano, Tatsuya Tanaka, Mitsugu Hosaka, Akiko Nakama, Akemi Kai, Kengo Saito, Hiroshi Shirasawa
    JOURNAL OF VIROLOGICAL METHODS 191(2) 141-147 2013年8月  査読有り
    Group C rotavirus (GCRV), astrovirus (AstV), and adenovirus (subgenus F AdenoV) are etiologic agents of acute nonbacterial gastroenteritis, which often represents community outbreaks. For the efficient detection of GCRV, AstV, and subgenus F AdenoV in stool specimens, a multiplex real-time PCR assay was developed to detect these three viruses simultaneously, with high sensitivity and specificity. In total, 8404 clinical specimens were collected between April 2008 and March 2011 and tested for GCRV, AstV, and subgenus F AdenoV by the multiplex real-time PCR, as well as for norovirus (NoV), sapovirus (Say), and group A rotavirus (GARV) by non-multiplex real-time PCR. Forty-one specimens were positive for GCRV, AstV, or subgenus F AdenoV, including 15 specimens that were also positive for NoV, SaV, or GARV. Multiple viruses were detected simultaneously in 29 out of 4596 (0.63%) specimens infected with at least one virus. The association rates of AstV and subgenus F AdenoV with other viruses were significantly higher than those of NoV, SaV, GARV, or GCRV. (C) 2012 Elsevier B.V. All rights reserved.
  • M. Shiiba, K. Shinozuka, K. Saito, K. Fushimi, A. Kasamatsu, K. Ogawara, K. Uzawa, H. Ito, Y. Takiguchi, H. Tanzawa
    BRITISH JOURNAL OF CANCER 108(9) 1817-1821 2013年5月  査読有り
    Background: MicroRNAs (miRNAs) are involved in essential biological activities, and have been reported to exhibit differential expression profiles in various cancers. Our previous study demonstrated that intercellular adhesion molecule-2 (ICAM2) inhibition induces radiosensitisation in oral squamous cell carcinoma (OSCC) cells. Thus, we hypothesised that certain miRNAs play crucial roles in radioresistance in OSCC by regulating ICAM2 expression. Methods: Because predicted target gene analyses revealed that microRNA-125b (miR-125b) potentially regulates ICAM2 mRNA expression, we examined the association between miR-125b and radioresistance. The expression of miR-125b was investigated by real-time quantitative reverse transcriptase-PCR. For a functional analysis, miR-125b was transfected to OSCC-derived cells. Results: A downregulated expression of miR-125b was found in OSCC-derived cell lines and OSCC samples. The miR-125b-transfected cells showed a decreased proliferation rate, enhanced radiosensitivity to X-ray irradiation and diminished ICAM2 mRNA expression. Moreover, miR-125b expression correlated with OSCC tumour staging and survival. Conclusion: These findings suggested that the downregulated miR-125b expression was associated with proliferation and radioresistance mechanisms, probably through ICAM2 signalling. Thus, controlling the expression or activity of miR-125b might contribute to suppressing proliferation and overcoming radioresistance in OSCC.
  • Ayumi Yamamoto, Atsushi Kasamatsu, Shunsaku Ishige, Kazuyuki Koike, Kengo Saito, Yukinao Kouzu, Hirofumi Koike, Yosuke Sakamoto, Katsunori Ogawara, Masashi Shiiba, Hideki Tanzawa, Katsuhiro Uzawa
    Journal of cancer research and clinical oncology 139(4) 533-42 2013年4月  査読有り
    PURPOSE: Sec8, a component of the exocyst complex, has been implicated in tethering of secretory vesicles to specific regions on the plasma membrane. To investigate the involvement of Sec8 in oral squamous-cell carcinoma (OSCC), we evaluated the expression status and effect of Sec8 in OSCC cell lines. METHODS: Sec8 mRNA and protein expressions in human OSCC cell lines were assessed by quantitative reverse transcriptase-polymerase chain reaction and immunoblotting. Functional analyses, proliferation assay, invasiveness assay, and gelatin zymography in Sec8 knockdown cells were performed. Also the correlation between Sec8 expression and the clinicopathological features in 98 primary OSCCs samples was evaluated by immunohistochemistry. RESULTS: Sec8 mRNA and protein expression were significantly up-regulated in all cell lines (p < 0.05). Sec8 knockdown cells were characterized by reduced cellular proliferation, invasiveness, and secretion of matrix metalloproteinases (MMPs) (MMP-2, proMMP-2, and proMMP-9). Sec8 protein expression in primary OSCCs also was significantly (p < 0.05) greater than in normal counterparts, and higher Sec8 expression was correlated with tumor size (p = 0.03). CONCLUSIONS: Our results suggested for the first time that Sec8 might play a specific role in OSCC progression by mediating MMP secretion.
  • Masashi Shiiba, Kengo Saito, Kazuaki Fushimi, Takashi Ishigami, Keiji Shinozuica, Dai Nakashima, Yukinao Kouzu, Hirofumi Koike, Atsushi Kasamatsu, Yosuke Sakamoto, Katsunori Ogawara, Katsuhiro Uzawa, Yuichi Takiguchi, Hideki Tanzawa
    INTERNATIONAL JOURNAL OF ONCOLOGY 42(4) 1197-1204 2013年4月  査読有り
    The aim of the present study was to identify a target molecule that could predict the efficacy of radiotherapy in oral squamous cell carcinoma (OSCC). We used DNA microarray analysis to identify differences in gene expression after X-ray irradiation. We compared the gene expression profiles between X-ray (8 Gy)-irradiated Ca9-22 cells (an OSCC-derived cell line) and unirradiated Ca9-22 cells. A total of 167 genes with a 2-fold higher level of expression induced by X-ray irradiation were identified. Lipocalin-2 (LCN2) had the greatest increase in expression after X-ray irradiation, and it was categorized in a network that has cancer-related functions with the Ingenuity Pathway Analysis tool. Upregulated expression of LCN2 mRNA was validated by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis. When the LCN2 gene was knocked down in OSCC cells (Ca9-22 and HSC-2) and lung cancer cells (A549) by using small interfering RNA, the radiosensitivity of these cells was enhanced. Our findings suggest that the overexpression of LCN2 is likely associated with radioresistance in oral cancer and lung cancer cells, and that LCN2 expression levels could be used to predict radioresistance. Thus, regulating the expression or function of LCN2 could enhance the radiation response, resulting in a favorable outcome of radiotherapy.
  • 中嶋大, 椎葉正史, 伏見一章, 齋藤謙悟, 鵜沢一弘, 丹沢秀樹
    日本口腔外科学会雑誌 59(6) 422-426 2013年  査読有り
  • Akiko Suganami, Taro Toyota, Shigetoshi Okazaki, Kengo Saito, Katsuhiko Miyamoto, Yasunori Akutsu, Hiroshi Kawahira, Akira Aoki, Yutaka Muraki, Tomoyuki Madono, Hideki Hayashi, Hisahiro Matsubara, Takashige Omatsu, Hiroshi Shirasawa, Yutaka Tamura
    BIOORGANIC & MEDICINAL CHEMISTRY LETTERS 22(24) 7481-7485 2012年12月  査読有り
    We have rationally designed and synthesized a novel near-infrared (NIR) photoactivating probe, designated by iDOPE, in which an indocyanine green (ICG) fluorophore is covalently conjugated with a phospholipid moiety, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), to incorporate into liposome bilayers. NIR irradiation showed that iDOPE retained the optical and fluorescence properties of ICG and demonstrated photoactivator characteristics: fluorescence emission at around 820 nm in a solvent, singlet oxygen production, and concentration-dependent heat generation. Additionally, iDOPE was incorporated into liposome bilayers and maintained stable liposomally formulated iDOPE (LP-iDOPE) over 1 week under physiological conditions. We also observed the tumor-specific biodistribution of LP-iDOPE of in vivo xenografts. These findings suggest that LP-iDOPE might be a promising tool for NIR optical imaging, photodynamic therapy, and photothermal therapy. (C) 2012 Elsevier Ltd. All rights reserved.
  • Erika Uehara, Masashi Shiiba, Keiji Shinozuka, Kengo Saito, Yukinao Kouzu, Hirofumi Koike, Atsushi Kasamatsu, Yosuke Sakamoto, Katsunori Ogawara, Katsuhiro Uzawa, Hideki Tanzawa
    INTERNATIONAL JOURNAL OF ONCOLOGY 40(5) 1414-1422 2012年5月  査読有り
    ADAMs are a disintegrin and metalloproteinase family of membrane-associated metalloproteinases characterized by their multidomain structure, and have been reported to be associated with various malignant tumors. The aim of this study was to identify crucial members of the ADAM family in oral squamous cell carcinoma (OSCC), and to reveal their biological function and clinical significance. To clarify whether ADAM family genes are involved in OSCC, changes in the expression profile were investigated by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis and immunohistochemical analysis. Functional analysis was performed by comparing cellular proliferation of siADAM-transfected cell lines and parental cell lines. Real-time qRT-PCR analysis identified significantly upregulated expression of ADAM12 in OSCC-derived cell lines. This was validated in OSCC samples using real-time qRT-PCR and immunohistochemical staining. ADAM12 expression was correlated with TNM classification; significantly greater expression of ADAM12 was observed in tumors with higher T classification and more advanced stages. Moreover, siADAM12-transfected cells showed both a suppressed proliferation rate and increased transforming growth factor (TGF)-1 beta 3 expression. Our data indicate that ADAM12 is overexpressed in OSCC and might accelerate cellular proliferation. Its function may be associated with TGF-beta signaling. This study suggests that controlling the expression or activity of ADAM12 could be a useful strategy in the development of an effective cure for OSCC.
  • 中本 晋吾, 今関 文夫, 神田 達郎, 呉 霜, 宮村 達雄, 太和田 暁之, 新井 誠人, 藤原 慶一, 齋藤 謙悟, 白澤 浩, 横須賀 收
    肝臓 53(Suppl.1) A546-A546 2012年4月  
  • Tamura R, Kanda T, Imazeki F, Wu S, Nakamoto S, Tanaka T, Arai M, Fujiwara K, Saito K, Roger T, Wakita T, Shirasawa H, Yokosuka O
    J Infect Dis. 204(5) 793-801 2012年  査読有り
  • 中本 晋吾, 今関 文夫, 神田 達郎, 呉 霜, 太和田 暁之, 三方 林太郎, 多田 素久, 千葉 哲博, 新井 誠人, 藤原 慶一, 金井 文彦, 齋藤 謙悟, 白澤 浩, 横須賀 收
    肝臓 52(Suppl.1) A209-A209 2011年4月  
  • 中本 晋吾, 今関 文夫, 神田 達郎, 呉 霜, 太和田 暁之, 新井 誠人, 藤原 慶一, 齋藤 謙悟, 白澤 浩, 横須賀 收
    日本消化器病学会雑誌 108(臨増総会) A369-A369 2011年3月  
  • Masashi Shiiba, Hitomi Nomura, Keiji Shinozuka, Kengo Saito, Yukinao Kouzu, Atsushi Kasamatsu, Yosuke Sakamoto, Akiyuki Murano, Kanae Ono, Katsunori Ogawara, Katsuhiro Uzawa, Hideki Tanzawa
    ONCOLOGY REPORTS 24(1) 241-249 2010年7月  査読有り
    Serpins (serine protease inhibitors) are known as a diverse family of protease inhibitors; however, various other biological activities including tumor suppression, have been recently reported for these molecules. To clarify whether members of the serpin family are involved in OSCC (oral squamous cell carcinoma), global gene screening using microarray analysis was performed with OSCC-derived cell lines. A trend toward diminished expression was shown for some SERPIN genes located on 11q12-q13.1 and 18q21. mRNA expression of SERPIN genes at these chromosome regions was therefore analyzed using real-time quantitative RT-PCR (qRT-PCR) in 55 OSCC samples and matched normal tissue. Statistically significant decreases in expression were found for SERPINB12 (P=0.001), SERPINB13 (P=0.001), SERPINB4 (P=0.042), SERPINB3 (P&lt;0.001), SERPINB11 (P&lt;0.001), SERPINB7 (P=0.021) and SERPINB2 (P=0.018). All of these genes are located on 18q21, the known location of the serpin gene cluster. The results strongly suggest that this chromosome region plays a crucial role in OSCC. Some serpin members in the region might be involved in tumor suppression, or there might be unidentified tumor suppressor genes within or near the chromosome region.
  • 森部 久仁一, 壬生 総子, 齋藤 謙悟, 東 顕二郎, 白澤 浩, 山本 恵司
    Drug Delivery System 25(3) 305-305 2010年5月  
  • Yukio Yamano, Katsuhiro Uzawa, Kengo Saito, Dai Nakashima, Atsushi Kasamatsu, Hirofumi Koike, Yukinao Kouzu, Keiji Shinozuka, Ken Nakatani, Kenji Negoro, Shigeyuki Fujita, Hideki Tanzawa
    INTERNATIONAL JOURNAL OF CANCER 126(2) 437-449 2010年1月  査読有り
    Resistance to cisplatin is a major obstacle to successful treatment of head and neck squamous cell carcinoma (HNSCC). To investigate the molecular mechanism of this resistance, we compared the gene expression profiles between the cisplatin-sensitive SCC cell lines (Sa-3, H-1 and KB) and the cisplatin-resistant cell lines established from them (Sa-3R, H-1R and KB-R) using Affymetrix U133 Plus 2.0 microarray. We identified 199 genes differentially expressed in each group. To identify important functional networks and ontologies to cisplatin resistance, the 199 genes were analyzed using the Ingenuity Pathway Analysis Tool. Fifty-one of these genes were mapped to genetic networks, and we validated the top-10 upregulated genes by real-time reverse transcriptase-polymerase chain reaction. Five novel genes, LUM, PDE3B, PDGF-C, NRG1 and PKD2, showed excellent concordance with the microarray data. In 48 patients with oral SCC (OSCC), positive immunohistochemical staining for the five genes correlated with chemoresistance to cisplatin-based combination chemotherapy. In addition, the expression of the five genes predicted the patient outcomes with chemotherapy. Furthermore, siRNA-directed suppressed expression of the five genes resulted in enhanced susceptibility to cisplatin-mediated apoptosis. These results suggested that these five novel genes have great potential for predicting the efficacy of cisplatin-based chemotherapy against OSCC. Global gene analysis of cisplatin-resistant cell lines may provide new insights into the mechanisms underlying clinical. cisplatin resistance and improve the efficacy of chemotherapy for human HNSCC.
  • Kengo Saito, Hiroshi Shirasawa, Naohisa Isegawa, Masashi Shiiba, Katsuhiro Uzawa, Hideki Tanzawa
    ORAL ONCOLOGY 45(12) 1021-1027 2009年12月  査読有り
    Oncolytic virotherapy utilizes viruses that can selectively destroy cancer cells without harming normal tissues. Clinical trials of oncolytic viruses show that most oncolytic agents are well tolerated and safe. The virotherapeutic agents currently in use have limited potency when administered alone; however, combination therapy using virotherapeutic agents and conventional anticancer agents, such as chemotherapeutics, radiation, and gene therapy, exhibits encouraging levels of efficacy. Advances in recombinant DNA technology have allowed the development of viruses that are tumor-selective and armed with transgenes, increasing the application potential and efficacy of this novel anticancer therapy. Here, we review the development of oncolytic viruses and the clinical trials of oncolytic virotherapy for oral cancers. We discuss current issues and perspectives of this evolving anticancer therapy, highlighting the potential applications of a unique, naturally occurring oncolytic virus, Sindbis virus. (C) 2009 Elsevier Ltd. All rights reserved.
  • 篠塚 啓二, 鵜澤 一弘, 根来 健二, 山野 由紀男, 伊豫田 学, 小越 健次, 野村 仁美, 齋藤 謙悟, 神津 由直, 嶋田 健, 椎葉 正史, 武川 寛樹, 横江 秀隆, 藤田 茂之, 丹沢 秀樹
    日本口腔外科学会雑誌 55(Suppl.) 204-204 2009年9月  
  • K. Saito, K. Uzawa, A. Kasamatsu, K. Shinozuka, K. Sakuma, M. Yamatoji, M. Shiiba, Y. Shino, H. Shirasawa, H. Tanzawa
    BRITISH JOURNAL OF CANCER 101(4) 684-690 2009年8月  査読有り
    BACKGROUND: Sindbis virus (SIN) infection causes no or only mild symptoms (fever, rash, and arthralgia) in humans. However, SIN has a strong cytopathic effect (CPE) on various cancer cells. This study focuses on the oncolytic activity of SIN AR399 on oral cancer cells compared with reovirus, a well-known oncolytic virus that targets cancer cells. METHODS: We analysed the cytotoxicity and growth of SIN in 13 oral squamous cell carcinoma (OSCC) cell lines (HSC-2, HSC-3, HSC-4, Ca9-22, H-1, Sa-3, KON, KOSC-2, OK-92, HO-1-N1, SCC-4, SAT, SKN-3) and normal human oral keratinocytes (NHOKs). RESULTS: Sindbis virus infection induced CPE in 12 OSCC cell lines at a low multiplicity of infection (MOI) of 0.01, but not in the OSCC cell line, HSC-4 or NHOKs. Sindbis viral growth was not observed in NHOKs, whereas high SIN growth was observed in all OSCC cell lines, including HCS-4. The cytotoxicity and growth of SIN was the same as reovirus at an MOI of 20 in 12 OSCC cell lines. The CPE was shown, by terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labelling assays, to be apoptotic cell death. Furthermore, quantitative RT-PCR of mRNA in HSC-3 and HSC-4 cells after SIN infection showed that activation of caspases, cytochrome c, and I kappa B alpha was associated with SIN-induced apoptosis. CONCLUSION: As a replication-competent oncolytic virus, SIN may be a useful therapeutic modality for oral cancers. British Journal of Cancer (2009) 101, 684-690. doi: 10.1038/sj.bjc.6605209 www.bjcancer.com Published online 28 July 2009 (C) 2009 Cancer Research UK
  • Kenji Negoro, Yukio Yamano, Dai Nakashima, Kengo Saito, Ken Nakatani, Masashi Shiiba, Hiroki Bukawa, Hidetaka Yokoe, Katsuhiro Uzawa, Takeshi Wada, Hideki Tanzawa, Shigeyuki Fujita
    ONCOLOGY REPORTS 21(2) 443-449 2009年2月  査読有り
    We previously established H-1R cells, a cisplatin (CDDP)-resistant cell line, from H-1 cells, a CDDP-sensitive oral carcinoma cell line. The aim of this study was to identify the molecular mechanism of cross-resistance to antitumor drugs containing a platinum agent in H-1R cells. The 3-(3, 4-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay and clonogenecity assay indicated that H-1R cells showed strong cross-resistance to carboplatin, nedaplatin and oxaliplatin. The expression status of the copper transporter and organic cation transporters was confirmed by real-time quantitative reverse transcriptase-polymerase chain reaction. The transporters ATP7A, ATP7B, hCtrl, hOCT1 and hOCT2 were up-regulated, whereas hOCT3 was down-regulated. The cellular glutathione level was elevated 2-fold in H-1R cells compared with H-1 cells. Our results suggested that H-1 and H-1R cells may be useful in searching for candidate genes responsible for cross-resistance to platinum derivatives and for further studies to understand the mechanism of platinum resistance.
  • T. Ishigami, K. Uzawa, K. Fushimi, K. Saito, Y. Kato, D. Nakashima, M. Higo, Y. Kouzu, H. Bukawa, T. Kawata, H. Ito, H. Tanzawa
    BRITISH JOURNAL OF CANCER 98(8) 1357-1365 2008年4月  査読有り
    We recently identified genes and molecular pathways related to radioresistance of oral squamous cell carcinoma (OSCC) using Affymetrix GeneChip. The current study focused on the association between one of the target genes, intercellular adhesion molecule 2 (ICAM2), and resistance to X-ray irradiation in OSCC cells, and evaluated the antitumor efficacy of combining ICAM2 small interfering RNA (siRNA) and X-ray irradiation. Downregulation of ICAM2 expression by siRNA enhanced radiosensitivity of OSCC cells with the increased apoptotic phenotype via phosphorylation (ser473) of AKT and activation of caspase-3. Moreover, overexpression of ICAM2 induced greater OSCC cell resistance to the X- ray irradiation with the radioresistance phenotype. These results suggested that ICAM2 silencing is closely related to sensitivity of OSCC cells to radiotherapy, and that ICAM2 may be an effective radiotherapeutic target for this disease.
  • Masakazu Kono, Koichiro Tatsumi, Alberto M. Imai, Kengo Saito, Takayuki Kuriyama, Hiroshi Shirasawa
    ANTIVIRAL RESEARCH 77(2) 150-152 2008年2月  査読有り
    The antiviral effects of chloroquine (CQ) on human coronavirus 229E (HCoV-229E) infection of human fetal lung cell line, L 132 are reported. CQ significantly decreased the viral replication at concentrations lower than in clinical usage. We demonstrated that CQ affects the activation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK). Furthermore, p38 MAPK inhibitor, SB203580, inhibits CPE induced by HCoV-229E infection and viral replication. Our findings suggest that CQ affects the activation of MAPKs, involved in the replication of HCoV-229E. (C) 2007 Elsevier B.V. All rights reserved.
  • Ken Iesato, Koichiro Tatsumi, Kengo Saito, Takashi Ogasawara, Seiichiro Sakao, Yuji Tada, Yasunori Kasahara, Katsushi Kurosu, Nobuhiro Tanabe, Yuichi Takiguchi, Takayuki Kuriyama, Hiroshi Shirasawa
    RESPIRATION 76(4) 434-441 2008年  査読有り
    Background: Respiratory syncytial virus (RSV) infection could be related to airway inflammation as well as exacerbation of chronic obstructive pulmonary disease (COPD). Tiotropium bromide decreases the frequency of exacerbation in patients with COPD; however, the mechanisms of tiotropium bromide to reduce the chances of exacerbation have not been defined. One potential mechanism could be that tiotropium bromide protects against RSV infection in epithelial cells. Objective: To examine whether tiotropium bromide affects RSV replication in HEp-2 cells. Methods: The supernatant titer of RSV was calculated by methylcellulose plaque assay after RSV innoculation. Intracellular RSV and ICAM-1 mRNA were measured by PCR. Syncytium formation was observed by light microscopy. Intracellular RSV fusion protein and RhoA protein were detected by Western blot analysis. Furthermore, RhoA activity, ICAM-1 expression and inflammatory cytokines in cultured supernatant were measured by binding assay, immunofluorescence staining and ELISA, respectively. Results: Tiotropium bromide decreased the supernatant titer of RSV, and it inhibited syncytium formation, RhoA activation and ICAM-1 expression. Moreover, it suppressed the production of IL-6 and IL-8 after RSV infection. Conclusions: The antiviral effects of tiotropium bromide regarding RSV replication are partly due to inhibition of RhoA activity and ICAM-1 expression. Tiotropium bromide decreases RSV replication and may modulate airway inflammation by reducing the production of inflammatory cytokines. Copyright (c) 2008 S. Karger AG, Basel
  • Takeshi Onda, Katsuhiro Uzawa, Dai Nakashima, Kengo Saito, Yasuo Iwadate, Naohiko Seki, Takahiko Shibahara, Hideki Tanzawa
    CANCER RESEARCH 67(20) 9643-9648 2007年10月  査読有り
    Using proteomic selection, functional verification, and clinical validation, we identified specific down-regulation of Lin-7C/ VEL13/MALS-3 (Lin-7C), which marks oral squamous cell carcinoma (OSCC) metastasis. Despite a rarity of sequence variations in the Lin-7C gene in both primary OSCC and OSCCderived cells, a high prevalence of hypermethylation was detected in the CpG island region that strongly correlated with its down-regulation. Inducible Lin-7C mRNA by experimental demethylation was found in all OSCC cells tested. Overexpression of the Lin-7C gene in an OSCC cell clone does not contribute to underproliferation but results in a noninvasive phenotype with elevated)3-catenin expression. Experimental metastases in multiple organs of immunodeficient mice were inhibited in cells expressing Lin-7C. Finally, the Lin-7C expression status in primary tumors afforded significantly (P &lt; 0.001) high accuracy for predicting lymph node metastasis. These results establish Lin-7C as a novel target of early detection, prevention, and therapy for OSCC metastasis.
  • H. Nomura, K. Uzawa, Y. Yamano, K. Fushimi, T. Ishigami, Y. Kato, K. Saito, D. Nakashima, M. Higo, Y. Kouzu, K. Ono, K. Ogawara, M. Shiiba, H. Bukawa, H. Yokoe, H. Tanzawa
    BRITISH JOURNAL OF CANCER 97(6) 792-801 2007年9月  査読有り
    To characterise Ca2+ -binding protein gene expression changes in oral squamous cell carcinomas (OSCCs), we compared the gene expression profiles in OSCC-derived cell lines with normal oral tissues. One hundred Ca2+ -binding protein genes differentially expressed in OSCCs were identified, and genetic pathways associated with expression changes were generated. Among genes mapped to the network with the highest significance, glucose-regulated protein 94 kDa (Grp94) was evaluated further for mRNA and protein expression in the OSCC cell lines, primary OSCCs, and oral premalignant lesions (OPLs). A significant (P &lt; 0.001) overexpression of Grp94 protein was observed in all cell lines compared to normal oral epithelium. Immunohistochemical analysis showed highly expressed Grp94 in primary OSCCs and OPLs, whereas most of the corresponding normal tissues had no protein immunoreaction. Real-time quantitative reverse transcriptase-PCR data agreed with the protein expression status. Moreover, overexpression of Grp94 in primary tumours was significantly (P &lt; 0.001) correlated with poor disease-free survival. The results suggested that Grp94 may have potential clinical application as a novel diagnosis and prognostic biomarker for human OSCCs.
  • Kenji Negoro, Yukio Yamano, Kazuaki Fushimi, Kengo Saito, Ken Nakatani, Masashi Shiiba, Hidetaka Yokoe, Hiroki Bukawa, Katsuhiro Uzawa, Takeshi Wada, Hideki Tanzawa, Shigeyuki Fujita
    INTERNATIONAL JOURNAL OF ONCOLOGY 30(6) 1325-1332 2007年6月  査読有り
    To investigate the mechanism of the resistance to cisplatin (CDDP), we established the CDDP-resistant cell line, KB-R, from CDDP-sensitive oral carcinoma cell line, KB. The 3-(3, 4-dimethyl-thiazol-2-yl) 2, 5-diphenyltetrazolium bromide (MTT) assay indicated that KB-R is 5.5-fold more resistant to CDDP than KB. Microarray analysis indicated that the expression levels of 1,718 genes were elevated at least fivefold or more in KB-R, compared with KB. The expression status of ATP binding cassette (ABC) transporter genes, which belong to multi-drug resistance genes, was confirmed by semi-quantitative reverse transcriptase-polymerase chain reaction and real-time PCR. MRP1 and MRP2 were up-regulated, whereas MDR1 was down-regulated. Pathway and ontology analysis using the Ingenuity Pathway Analysis tool indicated three highly significant genetic networks including 105 of the 1,718 overexpressed genes and one network including 35 'cell-to-cell signaling and interaction' related genes. Our results suggested that these cell lines, KB and KB-R, may be useful for searching the candidate genes responsible for CDDP-resistance and for further study to understand the mechanism of CDDP-resistance.
  • Takashi Ishigami, Katsuhiro Uzawa, Morihiro Higo, Hitomi Nomura, Kengo Saito, Yoshikuni Kato, Dai Nakashima, Masashi Shiiba, Hiroki Bukawa, Hidetaka Yokoe, Tetsuya Kawata, Hisao Ito, Hideki Tanzawa
    INTERNATIONAL JOURNAL OF CANCER 120(10) 2262-2270 2007年5月  査読有り
    To identify genes associated with radioresistant oral squamous cell carcinoma (OSCC), we compared gene expression signatures between OSCC cell lines exhibiting radioresistance and cells with radiosensitivity after X-ray irradiation in a dose-dependent manner using Affymetrix GeneChip analysis with Human Genome-U133 plus 2.0 GeneChip. The microarray data identified 167 genes that were significantly overexpressed in radioresistant cells after X-ray irradiation. Among the genes identified, 40 were mapped to 3 highly significant genetic networks identified by the Ingenuity Pathway Analysis tool. Gene ontology analysis showed that cancer-related function had the highest significance. The 40 genes included 25 cancer-related genes that formed I network and were categorized by function into growth and proliferation, apoptosis, and adhesion. Furthermore, real-time quantitative reverse transcriptase-polymerase chain reaction showed that the mRNA expression levels of the 25 genes were higher in radioresistant cells than in radiosensitive cells in a dose-dependent manner and in a time-dependent manner. Our results suggest that the identified genes help to elucidate the molecular mechanisms of the radioresistance of OSCC and could be radiotherapeutic molecular markers for choosing the appropriate radiotherapy for this disease. (c) 2007 Wiley-Liss, Inc.

MISC

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書籍等出版物

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講演・口頭発表等

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担当経験のある科目(授業)

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共同研究・競争的資金等の研究課題

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産業財産権

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