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  2. 吉村 久志

吉村 久志

ヨシムラ ヒサシ  (Hisashi YOSHIMURA)

基本情報

所属
日本獣医生命科学大学 獣医学部 獣医保健看護学科 応用部門 病態病理学研究分野 准教授
学位
博士（獣医学）(日本獣医生命科学大学)
J-GLOBAL ID
200901036410736384
researchmap会員ID
6000014246
外部リンク

JCVP認定獣医病理学専門家

 

日本獣医生命科学大学 獣医保健看護学科 病態病理学研究分野の私設ホームページはこちら

 

●奄美群島の稀少な野生動物死亡例の病理学的研究 2017年～現在

　奄美群島の動物病院の先生方などからのご依頼により、アマミノクロウサギやアマミトゲネズミなどの稀少な野生動物が死亡しているのが見つかった場合や、傷病で保護後に治療の甲斐なく死亡した場合に、その死因について病理学的に調査しています。これにより野生下で危険な伝染病が発生していないかのモニタリングや、今後の保護個体の治療法の改善に役立てています。

・J Comp Pathol. 2023 Accept.
Infective endocarditis with systemic bacterial embolism caused by Staphylococcus aureus in a free-ranging Amami rabbit (Pentalagus furnessi)
M. Konnai, M Yamamoto (co-first author), K. Ito, H. Yamabe, T. E. Kishimoto, H. Aoki, Y. Machida, M. Michishita, M. Haritani, H. Yoshimura.
・Int J Parasitol Parasites Wildl. 2022 18:194-200.
Three new species of Eimeria (Apicomplexa: Eimeriidae) from the Amami rabbit, Pentalagus furnessi (Mammalia: Leporidae)
T. Tokiwa, S. Chou, H. Kitazoe, K. Ito, R. Torimoto, Y. Shoshi, C. Sanjoba, M. Yamamoto, H. Yoshimura.
・Int J Parasitol Parasites Wildl. 2019 9:244-247.
Toxoplasma gondii infection in Amami spiny rat on Amami-Oshima Island, Japan
T. Tokiwa, H. Yoshimura (co-first author), S. Hiruma, Y. Akahori, A. Suzuki, K. Ito, M. Yamamoto, K. Ike.
・Parasitol Int. 2020 76:102058.
Alien parasitic infections in the endangered Ryukyu long-furred rat (Diplothrix legata) on Amami-Oshima Island, Japan
T. Tokiwa, H. Yoshimura, K. Ito, S. Chou, M. Yamamoto.

 

●動物園飼育下ニホンライチョウに発生する疾病の病理学的研究 2015年～現在

国の特別天然記念物に指定されているニホンライチョウは、地球温暖化などの影響により急激に生息数が減少しています。そこで環境省により保護増殖事業計画が策定され、2015年からニホンライチョウを動物園で飼育・繁殖し、将来的に野生に再導入する試み（生息域外保全）が始まりました。しかし、高山帯の冷涼な環境に生息するニホンライチョウは感染症に弱いなど、飼育を成功させるにはニホンライチョウに発生する疾病を解明する必要があります。当研究室は動物園飼育開始時から本事業に協力し、ニホンライチョウの疾病を病理学的に研究しています。

 

●イヌの乳腺腫瘍の分子病理学的研究 2010年～現在

　雌イヌにおいて発生頻度の高い腫瘍である乳腺腫瘍を研究テーマの一つにしています。近年、ヒト医療では癌に高発現する分子を狙い撃ちにする分子標的治療法が発展しています。イヌの乳腺腫瘍においても、癌の進行に重要な役割を果たし、治療標的になり得る候補分子を探索しています。

　S100蛋白の一つであるS100A4は、イヌの正常乳腺や良性の乳腺病変では発現しないにもかかわらず、一部の悪性乳腺腫瘍、特に退形成癌と呼ばれる最も悪性度の高い乳腺腫瘍の亜型において発現がみられました。S100A4を発現するイヌの乳腺癌から新たな培養細胞株NV-CMLを樹立し、RNA干渉技術を用いてS100A4の発現をノックダウンしたところ培養細胞の増殖能や遊走能が低下しました。このことからS100A4がイヌの乳腺癌の増殖や運動機能に関わっており、治療標的分子候補となる可能性が示唆されました。

　NestinはVI型中間径フィラメントに分類される細胞骨格蛋白で、神経幹細胞のマーカーとされていました。イヌの乳腺におけるnestinの発現を検討したところ、正常乳腺や良性の乳腺増殖性病変の腺上皮細胞には発現されないにもかかわらず、3割程度の悪性乳腺腫瘍、特に転移や増殖活性が高いなどの高悪性度の性質を持つ乳腺癌の腺上皮細胞には発現していることがわかりました。またnestinの発現は、間葉系マーカーであるvimrntinの発現と相関性を示しました。さらにイヌの乳腺癌培養細胞におけるnestinの発現を、RNA干渉技術によりノックダウンしたところ、nestinの発現が低下した癌細胞は、増殖能や移動能などが低下することが判明しました。このようにnestinがイヌの乳腺癌の悪性挙動の一部に関与している可能性が示唆されました。

・Vet Pathol. 2019 56(3):389-398.
Expression and Roles of S100A4 in Anaplastic Cells of Canine Mammary Carcinomas
H. Yoshimura, A. Otsuka, M. Michishita, M. Yamamoto, M. Ashizawa, M. Zushi, M. Moriya, D. Azakami, K. Ochiai, Y. Matsuda, T. Ishiwata, S. Kamiya, K. Takahashi.
・Vet Pathol. 2021 58(5):994-1003.
Involvement of Nestin in the Progression of Canine Mammary Carcinoma
H. Yoshimura, M. Moriya, A. Yoshida, M. Yamamoto, Y. Machida, K. Ochiai, M. Michishita, T. Nakagawa, Y. Matsuda, K. Takahashi, S. Kamiya, T. Ishiwata.

 

●イヌの乳腺腫瘍の分類に関する病理学的研究 2010年～現在

1999年のイヌの乳腺腫瘍のWHO分類では、比較的悪性度の高い組織型とされた単純癌（simple carcinoma）は「腺上皮あるいは筋上皮細胞のどちらか一方のみからなる癌」と定義されていました。また腺上皮と筋上皮が混在する腫瘍において、出現する筋上皮成分は異型性をほとんど示さないと考えられていました。しかしその後、腺上皮と筋上皮を免疫染色で鑑別できるいくつかの有用な抗体がみつかり、これまで形態学的に腺上皮と考えられていた異型性の高い細胞の中に、筋上皮由来のものがあることがわかってきていました。

そこで単純癌の一亜型である充実癌（solid carcinoma）と過去に診断されていた72症例を免疫染色結果に基づき再分類したところ、23症例が腺上皮由来の単純性充実癌（真の単純癌）、11症例が筋上皮由来の単純癌（悪性筋上皮腫）、38症例が腺上皮と筋上皮が混在した二相癌であることが判明しました。そして腺上皮由来の単純癌に比べて、筋上皮成分を含む残り二つの型は予後不良を示唆する病理学的指標がはるかに良好でした。このように腺上皮由来の単純性充実癌と筋上皮成分を含む二つの型は、予後を予測するためにも別の分類にする必要があることを提案しました。

これらの成果などにより、現在のイヌの乳腺腫瘍分類では単純癌は「腺上皮のみから成る癌」と定義され、筋上皮のみからなる癌は悪性筋上皮腫に分類されています。また腺上皮と筋上皮の両方に悪性の所見を示す二相性の癌は、癌及び悪性筋上皮腫（carcinoma & malignant myoepithelioma）という分類が設けられています。

・Vet Pathol. 2014 51(6):1090-5.
Differences in indicators of malignancy between luminal epithelial cell type and myoepithelial cell type of simple solid carcinoma in the canine mammary gland
H. Yoshimura, R. Nakahira, T.E. Kishimoto, M. Michishita, K. Ohkusu-Tsukada, K. Takahashi.

 

●ヒトの膵癌における長鎖ノンコーディングRNAの研究 2012年～2020年

長鎖ノンコーディングRNAは蛋白質をコードしないRNAで、以前は役割を持たないと考えられていましたが、近年様々な機能が発見されて注目されています。最も難治性の癌の一つであるヒトの膵癌の培養細胞において、マイクロアレイにより転移に関係する遺伝子発現を調べたところ、長鎖ノンコーディングRNAの一つであるH19が見出されました。またin situ hybridization法によりヒトの膵癌の臨床検体において、特に高グレードの症例でH19の発現がみられることを確認しました。そこでヒト膵癌培養細胞においてH19の発現を上下させたところ、運動能が変化することがわかりました。さらにH19の発現を低下させた細胞株は、免疫不全マウスに移植しても転移巣形成が著しく少ないことがわかりました。このように長鎖ノンコーディングRNA H19はヒト膵癌の転移に重要な役割を果たしていることが示唆されました。

・Lab Invest. 2018 98(6):814-824.
Reduced expression of the H19 long non-coding RNA inhibits pancreatic cancer metastasis
H. Yoshimura, Y. Matsuda, M. Yamamoto, M. Michishita, K. Takahashi, N. Sasaki, N. Ishikawa, J. Aida, K. Takubo, T. Arai, T. Ishiwata.
・Front Biosci (Landmark Ed). 2018 23:614-625.
Expression and role of long non-coding RNA H19 in carcinogenesis
H. Yoshimura, Y. Matsuda, M. Yamamoto, S. Kamiya, T. Ishiwata.

 

●ペットのジャンガリアンハムスターの乳腺腫瘍の病理学的検索 2008年～2015年

アニメの人気で日本で飼育数が増えたジャンガリアンハムスターには、しばしば乳腺腫瘍が発生します。病理検査に提出されたジャンガリアンハムスターの乳腺腫瘍45症例を病理組織学的に分類したところ腺腫14例、腺癌18例、脂質産生癌1例、腺扁平上皮癌2例、悪性腺筋上皮腫2例、良性混合腫瘍1例、癌肉腫7例といった多様な亜型に分けられました。特に比較的発生頻度の高かった癌肉腫は、風船様細胞（balloon cell）と名付けた特徴的な大型空胞を有する腫瘍細胞が混じる独特の組織像を呈していました。また上皮成分と間葉成分の間に移行像が認められることから、これらは真の癌肉腫ではなく、上皮間葉転換により生じる腫瘍であることが示唆されました。

・Vet Pathol. 2015 Nov;52(6):1227-34.
Characterization of Spontaneous Mammary Tumors in Domestic Djungarian Hamsters (Phodopus sungorus)
H. Yoshimura, N. Kimura-Tsukada, Y. Ono, M. Michishita, K. Ohkusu-Tsukada, Y. Matsuda, T. Ishiwata, K. Takahashi.
・J Vet Diagn Invest. 2010 22(2):305-9.
Lipid-rich carcinoma in the mammary gland of a Djungarian hamster (Phodopus sungorus)
H. Yoshimura, N. Kimura, R. Nakahira, M. Michishita, K. Ohkusu-Tsukada, K. Takahashi.

 

●イヌやネコの乳腺腫瘍における癌間質微小環境の研究 2008年～2015年

癌組織は癌細胞だけではなく間質を構成する細胞や細胞外基質が含まれています。近年、癌細胞は正常な細胞である間質細胞に働きかけ、癌細胞と間質細胞の相互作用により癌が進行していくと考えられるようになってきました。特に癌間質の線維芽細胞は癌関連線維芽細胞（cancer associated fibroblasts; CAFs）と呼ばれて、重要視されています。

イヌの乳腺腫瘍におけるCAFsの出現を調べるために、CAFsがα-smooth muscle actin（αSMA）を発現する筋線維芽細胞の性質を示すことを指標に検討したところ、高悪性度の乳腺腫瘍において間質に筋線維芽細胞が有意に多く出現していることがわかりました。またヒトの癌の浸潤に関わるとされる細胞外基質蛋白であるテネイシン-cを免疫染色で調べたところ、イヌの乳腺腫瘍では間質における発現と基底膜における発現の二つのパターンがあり、間質におけるテネイシン-c発現は高悪性度の乳腺癌で有意に多い一方で、基底膜におけるテネイシン-c発現は良性の乳腺腫瘍でもしばしば認められました。二重免疫染色や、免疫染色-in situ hybridization重染色を実施してテネイシン-cの産生細胞を検討したところ、間質のテネイシン-cは筋線維芽細胞が産生していることがわかりました。このようにイヌの高悪性度の乳腺癌において、間質に出現する筋線維芽細胞がテネイシン-cを産生することで癌の進展に寄与している可能性が示唆されました。一方で、良性の乳腺腫瘍における基底膜領域に発現するテネイシン-cは筋上皮細胞が産生していることが判明し、筋線維芽細胞が産生するテネイシン-cとは別の機能があるのではないかと考えられました。

また同様の検討をネコの乳腺癌でも行ったところ、イヌの乳腺癌と比べて間質における筋線維芽細胞の出現とその周囲における細胞外基質テネイシン-cの発現が明らかに多く、ネコの乳腺癌の悪性度の高さを反映する結果が得られました。

・Vet Pathol. 2011 48(1):313-21.
Increased presence of stromal myofibroblasts and tenascin-C with malignant progression in canine mammary tumors.
H. Yoshimura, M. Michishita, K. Ohkusu-Tsukada, K. Takahashi.
・Histol Histopathol. 2011 26(3):297-305.
Appearance and distribution of stromal myofibroblasts and tenascin-C in feline mammary tumors.
H. Yoshimura, M. Michishita, K. Ohkusu-Tsukada, K. Takahashi.
・Vet Pathol. 2015 52(1):92-6.
Cellular sources of tenascin-C in canine mammary carcinomas.
H. Yoshimura, M. Michishita, K. Ohkusu-Tsukada, Y. Matsuda, T. Ishiwata, Z. Naito, K. Takahashi.

研究キーワード

 3

研究分野

 3

経歴

 9
もっとみる

学歴

 3

委員歴

 7
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受賞

 3

論文

 73
  • Keita Sakashita, Toshihiro Tokiwa, Ryotaro Suzuki, Taisei I., Mariko Suzuki, Asahi Itoi, Masami Yamamoto, Hisashi Yoshimura
    International Journal for Parasitology: Parasites and Wildlife 101046-101046 2025年2月  査読有り最終著者
  • Toshihiro TOKIWA, Hisashi YOSHIMURA, Mami TAKASE, Eigo KATO, Masateru MORISAKI, Tatsushi MORITA, Mitsuru KOUTAKA
    Journal of Veterinary Medical Science 87(2) 147-151 2025年  査読有り
  • 上田海那人, 原藤芽衣, 岸本拓也, 吉村久志, 山本昌美
    動物園水族館雑誌 66(1) 12-18 2024年6月  
  • Kana Matsumoto, Takuya Evan Kishimoto, Masami Yamamoto, Masaki Michishita, Kimimasa Takahashi, Hisashi Yoshimura
    Journal of Veterinary Diagnostic Investigation 35(6) 789-794 2023年10月2日  査読有り最終著者責任著者
  • Masaki Konnai, Masami Yamamoto, Keiko Ito, Hanae Yamabe, Takuya E. Kishimoto, Hiroshi Aoki, Yukino Machida, Masaki Michishita, Makoto Haritani, Hisashi Yoshimura
    Journal of Comparative Pathology 201 23-27 2023年1月  査読有り最終著者責任著者
  • Hisashi Yoshimura, Kazushi Torikai, Anna Takahashi, Masaki Michishita, Takuya E Kishimoto, Masami Yamamoto, Makoto Haritani, Kimimasa Takahashi, Shinji Kamiya
    Journal of Comparative Pathology 201 28-32 2023年1月  査読有り筆頭著者
  • Yuuki Shichi, Fujiya Gomi, Yoshibumi Ueda, Keisuke Nonaka, Fumio Hasegawa, Yasuko Hasegawa, Nae Hinata, Hisashi Yoshimura, Masami Yamamoto, Kimimasa Takahashi, Tomio Arai, Toshiyuki Ishiwata
    Biochemistry and Biophysics Reports 32 101339-101339 2022年12月  査読有り
  • 千葉 友章, 堂前 弘志, 北川 和也, 坂牧 朝仁, 大井 毅, 吉村 久志, 山本 昌美
    日本野生動物医学会誌 27(2) 145-148 2022年9月  査読有り
  • Yukino Machida, Marika Higo, So Doge, Tomokazu Nagashima, Takuya E. Kishimoto, Hisashi Yoshimura, Masami Yamamoto, Kazuki Okada, Naoko Yayoshi, Hitoshi Hatakeyama, Masaki Michishita
    Journal of Comparative Pathology 197 19-22 2022年9月  査読有り
  • Toshihiro Tokiwa, Shyun Chou, Hina Kitazoe, Keiko Ito, Ryouta Torimoto, Yuki Shoshi, Chizu Sanjoba, Masami Yamamoto, Hisashi Yoshimura
    International Journal for Parasitology: Parasites and Wildlife 18 194-200 2022年8月  査読有り最終著者
  • Norihiko Sasaki, Kazumi Hirano, Yuuki Shichi, Fujiya Gomi, Hisashi Yoshimura, Akira Matsushita, Masashi Toyoda, Toshiyuki Ishiwata
    Cancers 14(9) 2055-2055 2022年4月19日  査読有り
  • 上田海那人, 原藤芽衣, 岸本拓也, 吉村久志, 山本昌美
    日本野生動物医学会誌 27(1) 29-34 2022年3月  査読有り
  • Nanako Yamashita-Kawanishi, James K Chambers, Kazuyuki Uchida, Yumiko Tobari, Hisashi Yoshimura, Masami Yamamoto, Norio Yumoto, Hiroshi Aoki, Katsuaki Sugiura, Tohru Higuchi, Shigeaki Saito, Takeshi Haga
    Equine Veterinary Journal 53(6) 1199-1209 2021年11月  査読有り
  • Hisashi Yoshimura, Maiko Moriya, Ayaka Yoshida, Masami Yamamoto, Yukino Machida, Kazuhiko Ochiai, Masaki Michishita, Takayuki Nakagawa, Yoko Matsuda, Kimimasa Takahashi, Shinji Kamiya, Toshiyuki Ishiwata
    Veterinary Pathology 58(5) 994-1003 2021年5月31日  査読有り筆頭著者
    Nestin, a class VI intermediate filament protein, is known to be expressed in various types of human neoplasms, including breast cancer, and is associated with their progression. However, its expression and role in canine mammary tumors remain unknown. We analyzed nestin expression in canine mammary tumors using in situ hybridization and immunohistochemistry. We also investigated its role in a canine mammary carcinoma cell line using RNA interference. Nestin expression was not observed in luminal epithelial cells of any of the 62 cases of benign mammary lesions examined, although myoepithelial cells showed its expression in most cases. In 16/50 (32%) primary mammary carcinomas and 6/15 (40%) metastases of mammary carcinomas, cytoplasmic nestin expression was detected in luminal epithelial cells. In luminal cells of primary mammary carcinomas, its expression was positively related to several pathological parameters that indicate high-grade malignancy, including histological grading ( P < .01), vascular/lymphatic invasion ( P < .01), Ki-67 index ( P < .01), and metastasis ( P < .05). Immunohistochemistry revealed that nestin expression was related to vimentin expression in mammary carcinomas ( P < .01). This relationship was confirmed using reverse transcription-quantitative polymerase chain reaction using 9 cell lines derived from canine mammary carcinoma ( P < .01). Finally, nestin knockdown in canine mammary carcinoma cells using small interfering RNA inhibited cell proliferation and migration based on WST-8, Boyden chamber, and cell-tracking assays. These findings suggest that nestin may at least partially mediate these behaviors of canine mammary carcinoma cells.
  • Ayaka Hata, Yuto Suda, Midori Saeki, Tatsuki Shimamoto, Hisashi Yoshimura, Masami Yamamoto, Aki Fujiwara, Shinji Kamiya, Makoto Haritani
    Japanese Journal of Zoo and Wildlife Medicine 25(4) 141-145 2020年12月  査読有り
  • Norihiko Sasaki, Fujiya Gomi, Hisashi Yoshimura, Masami Yamamoto, Yoko Matsuda, Masaki Michishita, Hitoshi Hatakeyama, Yoichi Kawano, Masashi Toyoda, Murray Korc, Toshiyuki Ishiwata
    Cancers 12(10) 2976 2020年10月14日  査読有り
  • Masaki Michishita, Y. Ishizaki, Masaki Konnai, Yukino Machida, Rei Nakahira, Hitoshi Hatakeyama, Hisashi Yoshimura, Masami Yamamoto, Satoshi Soeta, Kazuhiko Ochiai, K. Misawa, Naoko Yugeta, Daigo Azakami
    Journal of Comparative Pathology 179 31-35 2020年8月  査読有り
  • Ritsu Shibata, Yukino Machida, Hitoshi Hatakeyama, Hisashi Yoshimura, Masami Yamamoto, Kazuhiko Ochiai, Kazuyoshi Uematsu, Masaki Michishita
    The Journal of veterinary medical science 82(2) 193-196 2020年2月18日  査読有り
    A 26-year and 6-month-old male sika deer that was kept at the Showa Park, Tokyo, Japan, collapsed and died of severe disease wasting and severe tabefaction. Grossly, numerous masses, 0.3-1.0 cm diameter, were dispersed throughout the liver. The multiple masses were composed of tumor cells, which had hypochromatic nuclei and abundant faintly eosinophilic cytoplasm, arranged in nests of various sizes. Immunohistochemically, tumor cells were positive for cytokeratin, chromogranin A, synaptophysin and gastrin. Ultrastructurally, the cytoplasm of the tumor cells contained abundant membrane-bound electron-dense granules. A metastatic lesion was observed in the renal, hepatic and pancreatic lymph nodes. On the basis of these findings, this tumor was diagnosed as a neuroendocrine carcinoma with metastases to the lymph nodes.
  • Toshihiro Tokiwa, Hisashi Yoshimura, Keiko Ito, Syun Chou, Masami Yamamoto
    Parasitology International 76(102058) 2020年1月  査読有り
  • M Michishita, A Fujiwara-Igarashi, S Suzuki, H Hatakeyama, Y Machida, H Yoshimura, M Yamamoto, D Azakami, K Ochiai, T Ishiwata, M Fujita
    Journal of comparative pathology 171 1-5 2019年8月  査読有り
    A 2-year-old neutered female Shiba dog exhibited laboured breathing for 1 month. Computed tomography of the thoracic cavity revealed multiple nodules (2-5 mm diameter) in the lungs. Grossly, the lungs were firm and normal in shape. The nodules were grey-white in colour. Microscopically, the nodules were non-encapsulated and exhibited an irregular shape. They were composed of polygonal or spindle cells with indistinct cell borders arranged in sheets. The cells had large, round, hyperchromatic nuclei and abundant pale eosinophilic cytoplasm with no atypia. Intrapulmonary arterial emboli and infiltration into the bronchioles were observed. Immunohistochemically, the cells were positive for vimentin and negative for cytokeratin, glial fibrillary acidic protein and α-smooth muscle actin. Ultrastructurally, the cells displayed cytoplasmic processes, desmosomes and intermediate filaments. These findings led to a diagnosis of diffuse pulmonary meningotheliomatosis with sarcomatous transformation. To the best of our knowledge, this is the first report of diffuse pulmonary meningotheliomatosis in a dog.
  • Yuuki Shichi, Norihiko Sasaki, Masaki Michishita, Fumio Hasegawa, Yoko Matsuda, Tomio Arai, Fujiya Gomi, Junko Aida, Kaiyo Takubo, Masashi Toyoda, Hisashi Yoshimura, Kimimasa Takahashi, Toshiyuki Ishiwata
    Scientific reports 9(1) 10871-10871 2019年7月26日  査読有り
    Pancreatic cancer, composed of heterogeneous cancer cells, alters epithelial to mesenchymal features during growth and metastasis. In this study, we aimed to characterize pancreatic ductal adenocarcinoma (PDAC) cells showing epithelial or mesenchymal features in 3D culture. In 3D culture, PK-1 cells had high E-cadherin and low vimentin expression and exhibited a round-like appearance encircled by flat cells. PANC-1 cells had high vimentin and low E-cadherin expression and formed grape-like spheres. PK-1 cells had secretary granules and many microvilli, desmosomes, and adherens junctions, while PANC-1 cells had few microvilli, adherens junction, and no desmosomes. Cytokeratin 7, trypsin, CA19-9, and E-cadherin were highly expressed in PK-1 cells but not in PANC-1 cells. Ki-67 was diffusely expressed in PANC-1 spheres but was restricted to the peripheral flat cells of PK-1 spheres. PANC-1 and PK-1 cells were positive for transforming growth factor (TGF) β receptor II and phosphorylated smad2/3, but PK-1 cells were smad4 negative. Taken together, 3D culture enhanced morphofunctional differences of PDAC cells showing epithelial or mesenchymal characteristics, and epithelial phenotype maintenance may be due to the ineffectiveness of the TGF- β pathway. Clarification of heterogeneity using 3D culture may be useful for development of individualized diagnostic and therapeutic methods in patients with PDAC.
  • Yukino Machida, Masaki Michishita, Hisashi Yoshimura, Takuya Kato, Shin-Ichi Hayama, Kimimasa Takahashi
    The Journal of veterinary medical science 81(7) 975-979 2019年7月11日  査読有り
    A 21-year-old male masked palm civet died after 2 months of continuous abdominal distention and poor appetite. Grossly, both musk glands were markedly swelled. Microscopically, round, polygonal and spindle neoplastic cells proliferated diffusely in the right musk gland and a metastatic focus was observed in the lung. The neoplastic cells had abundant cytoplasm with faintly eosinophilic inclusions that ultrastructurally corresponded to whorl aggregates of intermediate filaments. Immunohistochemically, these cells were positive for vimentin, cytokeratins and glial fibrillary acidic protein and negative for desmin. Based on these findings, the tumor was diagnosed as malignant rhabdoid tumor. Papillary adenoma was seen in the opposite musk gland. T-cell lymphoma of the lymph nodes, small intestine and liver was considered as the cause of death.
  • Toshihiro Tokiwa, Hisashi Yoshimura (co-first author), Sayoko Hiruma, Yukie Akahori, Ayami Suzuki, Keiko Ito, Masami Yamamoto, Kazunori Ike
    International Journal for Parasitology: Parasites and Wildlife 9 244-247 2019年6月  査読有り
  • Hisashi Yoshimura, Aya Otsuka, Masaki Michishita, Masami Yamamoto, Minori Ashizawa, Manami Zushi, Maiko Moriya, Daigo Azakami, Kazuhiko Ochiai, Yoko Matsuda, Toshiyuki Ishiwata, Shinji Kamiya, Kimimasa Takahashi
    Veterinary pathology 56(3) 389-398 2019年5月  査読有り
    S100A4 (metastasin), a member of the S100 protein family, was initially identified in metastatic cells and is well established as a marker of aggressive human cancer. However, expression and roles of S100A4 in canine mammary tumors have not been clarified. In this study, expression of S100A4 was examined immunohistochemically in normal, hyperplastic, and neoplastic mammary glands of dogs. In all normal and benign lesions, S100A4 was restricted to a few stromal fibroblasts and inflammatory cells. However, in 7 of 57 (12%) of the malignant tumors examined, cytoplasmic and nuclear expression of S100A4 was observed in epithelial tumor cells and stromal cells. Particularly, the frequency of S100A4-positive anaplastic carcinomas was high (4/8 cases, 50%). Next, we established a novel cell line, named NV-CML, from a S100A4-positive canine mammary carcinoma. The cultured NV-CML cells and the tumors that developed in the immunodeficient mice after subcutaneous injection of the cells maintained the immunophenotype of the original tumor, including S100A4 expression. Using this cell line, we examined the cellular functions of S100A4 using RNA interference. S100A4 expression level in NV-CML cells transfected with small interfering RNA (siRNA) targeting canine S100A4 (siS100A4) was reduced to about one-fifth of those with negative-control siRNA (siNeg). Cell proliferation in WST-8 assay and cell migration in Boyden chamber assay were significantly decreased in siS100A4-transfected cells compared with siNeg-transfected cells. These findings suggest that S100A4 may be related to progression of canine mammary carcinomas via its influence on cell growth and motility.
  • Norihiko Sasaki, Masashi Toyoda, Hisashi Yoshimura, Yoko Matsuda, Tomio Arai, Kaiyo Takubo, Junko Aida, Toshiyuki Ishiwata
    Oncotarget 9(78) 34719-34734 2018年10月5日  査読有り
    The long non-coding RNA H19 is highly expressed in several cancers, and the functions of H19 vary among cancer cell types. Recently, we reported that H19 contributes to the metastasis of pancreatic ductal adenocarcinoma (PDAC) cells and that inhibition of H19 reduces metastasis in vivo. However, the molecular mechanisms underlying the metastasis-promoting role of H19 in PDAC cells remain poorly elucidated. In this study, we clarified the mechanisms by which H19 regulates PDAC metastasis, with a focus on cancer stem cells (CSCs), by using H19-overexpressing and knockdown PDAC cells. Whereas the sphere-formation and invasion abilities of PDAC cells depended on H19 expression levels, other CSC characteristics of the cells, including stemness-marker expression and anticancer-drug resistance, were unaffected by H19 levels. Furthermore, metalloproteinase activity, a key mediator of invasion, was also independent of H19 expression. By contrast, H19 promoted cell adhesion through regulation of integrin and CD24 expression. Notably, the increased adhesion of H19-overexpressing cells was blocked by an anti-β1-integrin antibody, and this resulted in the inhibition of sphere formation and invasion. Thus, H19 plays critical roles in the CSC self-renewal and cell adhesion of PDAC that lead to invasion and metastasis. Our findings suggest that H19 represents a novel therapeutic target for the metastasis of pancreatic cancer.
  • Toshiyuki Ishiwata, Yoko Matsuda, Hisashi Yoshimura, Norihiko Sasaki, Shunji Ishiwata, Naoshi Ishikawa, Kaiyo Takubo, Tomio Arai, Junko Aida
    Pathology oncology research : POR 24(4) 797-805 2018年10月  査読有り
    Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a high incidence of distant metastasis and recurrence. Cancer stem cells (CSCs), which are pluripotent, self-renewable, and capable of forming tumors, contribute to PDAC initiation and metastasis and are responsible for resistance to chemotherapy and radiation. Three types of experimental methods are commonly used to identify CSCs: CSC-specific marker detection, a sphere-formation assay that reveals cell proliferation under non-adherent conditions, and detection of side-population (SP) cells that possess high intracellular-to-extracellular pump functions. Several CSC-specific markers have been reported in PDACs, including CD133, CD24, CD44, CXCR4, EpCAM, ABCG2, c-Met, ALDH-1, and nestin. There remains controversy regarding which markers are specific to PDAC CSCs and which are expressed alone or in combination in CSCs. Examining characteristics of isolated CSCs and discovering CSC-specific treatment options are important to improve the prognosis of PDAC cases. This review summarizes CSC-detection methods for PDAC, including CSC-marker detection, the sphere-formation assay, and detection of SP cells.
  • Hisashi Yoshimura, Yoko Matsuda, Masami Yamamoto, Masaki Michishita, Kimimasa Takahashi, Norihiko Sasaki, Naoshi Ishikawa, Junko Aida, Kaiyo Takubo, Tomio Arai, Toshiyuki Ishiwata
    Laboratory investigation; a journal of technical methods and pathology 98(6) 814-824 2018年6月  査読有り
    H19 is an oncofetal RNA expressed in the developing embryo as well as in bladder, breast, gastric, pancreatic, hepatocellular, and prostate cancers. Recent studies have shown that H19 enhances cancer invasion and metastasis; however, its roles in cancer remain controversial. In the current study, H19 exhibited the second largest increase (82.4-fold) and represented the only non-protein coding gene among 11 genes identified that were elevated over 10-fold in lung-metastasis-derived pancreatic cancer cells compared with their parental cells using a mouse metastatic model. Subsequently, we further clarified the roles of H19 in pancreatic cancer growth and metastasis using in vitro and in vivo techniques. In situ hybridization showed that H19 was detected in 23 of 139 invasive ductal carcinomas (17%), and that H19 expression positively correlated with higher histological grades (P < 0.0001). Overexpression of H19 in PANC-1 pancreatic cancer cells induced higher motilities, whereas H19 inhibition using shRNA and siRNA showed opposite results; however, cell growth rates were not impacted. Intravenous injection of H19 shRNA vector-transfected PANC-1 cells yielded marked inhibition of metastasis in the liver and lungs of immunodeficient mice. These findings suggest that H19 has important roles in pancreatic cancer metastasis, and that inhibition of H19 represents a novel candidate for pancreatic cancer therapy.
  • Hisashi Yoshimura, Yoko Matsuda, Masami Yamamoto, Shinji Kamiya, Toshiyuki Ishiwata
    Frontiers in Bioscience - Landmark 23(4) 614-625 2018年1月1日  査読有り
    With the recent advent of whole genome and transcriptome sequencing technologies, long noncoding RNAs have been brought into the spotlight in molecular biology. H19 was one of the first reported long non-coding RNAs its expression is high in embryonic organs and absent or greatly reduced in most adult tissues. Accumulating evidence suggests that H19 plays crucial roles in embryogenesis. However, its levels are increased in different cancers, including breast, hepato-gastrointestinal, urological, respiratory, and brain tumors. Although there have been several controversial reports as to whether H19 is oncogenic or tumor-suppressive, most studies have indicated that H19 is associated with growth, migration, invasion, and/or metastasis in many cancers however, its reported functional mechanisms vary among cancer types. Furthermore, serum H19 levels in patients with certain cancers have been suggested to be useful for diagnosis and prognosis. Thus, H19 long non-coding RNA might be a candidate for development of promising therapeutic and diagnostic modalities for several cancers. The purpose of this review is to provide an inclusive report on the functional role of H19 in different cancers.
  • K. Hagiwara, M. Michishita, H. Yoshimura, K. Ochiai, D. Azakami, T. Ishiwata, K. Takahashi
    JOURNAL OF COMPARATIVE PATHOLOGY 157(4) 266-269 2017年11月  査読有り
    A 21-year-old neutered female domestic shorthaired cat was presented with a history of inappetence, vomiting and haematuria. The cat was humanely destroyed at the owner's request and a necropsy examination was performed. A 0.8 x 0.5 x 0.5 cm mass was located in the left lobe of the pancreas. The mass was gelatinous in nature and the external and cut surfaces were pale yellow in colour. Microscopically, the mass was non-capsulated and comprised an accumulation of extracellular stromal mucin containing suspended neoplastic columnar epithelial cells forming tubular structures. Immunohistochemically, these cells diffusely expressed cytokeratin (CK) AE1/AE3, CK7 and carcinoembryonic antigen and were partially positive for CK19 and trypsin, but negative for vimentin. The tumour was diagnosed as a colloid carcinoma. The clinical presentation in this case was caused by chronic renal failure complicated by secondary renal hyperparathyroidism and associated metastatic calcinosis. To the best of our knowledge, this is the first report of colloid carcinoma arising from the pancreas in a cat. (C) 2017 Elsevier Ltd. All rights reserved.
  • Mio Ishimori, Masaki Michishita, Hisashi Yoshimura, Daigo Azakami, Kazuhiko Ochiai, Toshiyuki Ishiwata, Kimimasa Takahashi
    JOURNAL OF VETERINARY MEDICAL SCIENCE 79(9) 1503-1506 2017年9月  査読有り
    A 7-year-old female domestic rabbit suffered from labored respiration, poor appetite, mild anemia and thrombocytopenia. Radioscopic examination revealed masses in multiple locations including the intrapleural cavity and spleen. Forty-three days after the first visit to a private veterinary clinic, the rabbit died of severe respiratory distress. Microscopically, all of the masses were composed of round to polygonal neoplastic cells with distinct cell borders that were arranged in a sheet pattern. Multinucleated giant neoplastic cells were often observed. Some neoplastic cells had phagocytozed one or more erythrocytes. Immunohistochemical staining revealed that the neoplastic cells expressed vimentin, CD204, Iba-1 and lysozyme, but not CD163. Based on the morphological and immunohistochemical findings, this case was diagnosed as disseminated histiocytic sarcoma with hemophagocytosis.
  • M. Michishita, Y. Katori, H. Sasaki, R. D. Obara, R. Furumoto, M. Kato, R. Nakahira, H. Yoshimura, S. Soeta, T. Ishiwata, K. Takahashi
    JOURNAL OF COMPARATIVE PATHOLOGY 157(1) 57-60 2017年7月  査読有り
    A 5-year-old male miniature dachshund was presented with a dermal nodule on the left forelimb that increased to 5 mm in diameter over a 2-month period. Grossly, the nodule was firm, and both the external and cut surfaces were homogeneously pale pink in colour. Microscopically, the nodule was comprised of mainly plump endothelial cells and inflammatory cells; among the latter, lymphocytes were predominant, with few scattered plasma cells, mast cells and macrophages. Lymphoid follicles with germinal centres were often observed. Mitotic figures were not observed amongst the endothelial cells. Immunohistochemically, the endothelial cells were positive for vimentin, factor VIII-related antigen and CD31, and the surrounding cells were positive for smooth muscle actin. Lymphocytes expressed CD3 or BLA36. These findings led to a diagnosis of cutaneous angiolymphoid hyperplasia. To the best of our knowledge, this is the first report of a cutaneous proliferative disorder comprising an admixture of proliferating vascular endothelial cells and lymphocytic infiltration with follicle formation in a dog. (C) 2017 Elsevier Ltd. All rights reserved.
  • Masaki Michishita, Mariko Takagi, Takuya E. Kishimoto, Rei Nakahira, Takeshi Nogami, Hisashi Yoshimura, Hitoshi Hatakeyama, Daigo Azakami, Kazuhiko Ochiai, Kimimasa Takahashi
    JOURNAL OF VETERINARY DIAGNOSTIC INVESTIGATION 29(3) 325-330 2017年5月  査読有り
    A 35-mo-old spayed female mixed-breed cat with continuous vomiting, emaciation, and abdominal distention for 2 wk was presented to a private veterinary clinic for evaluation. At 71 d after the initial visit, the cat died with anemia, jaundice, and hypoalbuminemia, and was subjected to autopsy. Grossly, numerous firm masses, 0.5-2.5 cm diameter, were randomly located in the left lobe of the pancreas. Histologic examination revealed that the pancreatic mass consisted of 2 tumor cell types: mostly small round cells with a minority of epithelial cells. The small cells were arranged in nests of various sizes, which were separated by thin fibrous stroma, and had small, round, hyperchromatic nuclei, scant cytoplasm containing argyrophilic granules, and often formed rosettes. The epithelial cells formed luminal structures. Metastases were observed in the liver, greater omentum, and pancreatic, gastric, pulmonary, and mediastinal lymph nodes. Immunohistochemical examination revealed that the small cells were positive for vimentin, neuron-specific enolase, chromogranin A, cytokeratin (CK) AE1/AE3, and trypsin, whereas the epithelial cells were positive for AE1/AE3, trypsin, CK19, and nestin. Ultrastructurally, the small cells contained abundant electron-dense granules, similar to 200 nm diameter, whereas the epithelial cells had apical microvilli and numerous zymogen granules, similar to 300 nm diameter. These findings indicated that the tumor was a pancreatic neuroendocrine carcinoma with exocrine differentiation and systemic metastases.
  • Shinji Kamiya, Hisashi Yoshimura (co-first author), Keina Okada, Ayaka Yoshida, Yuki Fukuda, Masami Yamamoto, Satoshi Soeta, Kimimasa Takahashi
    HISTOLOGY AND HISTOPATHOLOGY 32(5) 499-502 2017年5月  査読有り
    Polyglucosan bodies (PGB) in the prostate of aged dogs without neurological signs were examined by light microscopy, histochemistry and immunohistochemistry. Prostatic PGB were round or oval and slightly basophilic. Most of the bodies were situated within the stromal smooth muscle cells. PGB were intensely positive for PAS, Best's carmine, Lugol's iodine and Grocott's methenamine silver method. Moreover, canine prostatic PGB were immunoreactive for monoclonal antibodies raised against human polyglucosan. The frequency of PGB in the smooth muscle cells was significantly correlated with the age of dogs. The occurrence of PGB in the canine prostate might be a non-specific finding related to ageing.
  • Yoko Matsuda, Toshiyuki Ishiwata, Hisashi Yoshimura, Kazuya Yamahatsu, Toshinari Minamoto, Tomio Arai
    CANCER SCIENCE 108(3) 354-361 2017年3月  査読有り
    The neuroepithelial stem cell marker nestin is a cytoskeletal protein that regulates cell proliferation, invasion, and stemness in various tumors, including pancreatic tumors. In the present study, we examined the expression and roles of phosphorylated nestin in pancreatic cancer cells. Nestin phosphorylation at threonines 315 (Thr315) and 1299 (Thr1299) was observed during mitosis in human pancreatic cancer cells. Nestin phosphorylation was positively correlated with a cell proliferation marker, MIB-1 expression in human pancreatic cancer samples. Transfection of MIA PaCa-2 cells with nestin mutated at Thr315 and/or Thr1299 (to suppress phosphorylation) resulted in lower proliferation rates than those in control groups. Transfecting MIA PaCa-2 cells with wild-type nestin or with nestin mutated at Thr315 increased migration and invasion. In contrast, transfection with nestin mutated at both phosphorylation sites (Thr315 and Thr1299) did not enhance cell migration or invasion. In an intra-splenic xenograft experiment using MIA PaCa-2 cells, tumors expressing the nestin double mutant formed fewer liver metastases than tumors expressing wild-type nestin. Nestin phosphorylation at these two sites was decreased upon treatment with inhibitors for cyclin dependent kinases, AKT, and Aurora in PANC-1 cells, which express a high baseline level of phosphorylated nestin. These findings suggest that phosphorylation of nestin at Thr315 and/or Thr1299 affects cell proliferation, and inhibition of both phosphorylation sites suppresses invasion and metastasis of human pancreatic cancer. Inhibiting nestin phosphorylation at these two sites may represent a novel therapeutic strategy for pancreatic cancer.
  • Hisashi Yoshimura, Masami Yamamoto, Maiko Moriya, Tomohiko Endo, Natsuko Sugiura, Takuya Kato, Yoko Matsuda, Toshiyuki Ishiwata, Hiroshi Kajigaya, Shinji Kamiya
    JOURNAL OF ZOO AND WILDLIFE MEDICINE 48(1) 265-268 2017年3月  査読有り
    A young adult, female, free-ranging Japanese raccoon dog (Nyctereutes procyonoides viverrinus) with scabies infection was found dead as a result of traumatic injuries presumed to reflect vehicular trauma. Necropsy showed a large solid mass located on the left ovarian region, occupying a third of the abdominal cavity. Histologically, the mass contained complex tissues derived from three germinal layers, with areas of cuboidal or columnar epithelium, keratinized squamous epithelium, bone, cartilage, and adipose tissue. This paper presents the first morphologic description of ovarian teratoma in a raccoon dog.
  • Yutaka Momota, Junya Yasuda, Nobuaki Arai, Masami Yamamoto, Hisashi Yoshimura, Mitsutaka Ikezawa, Shuji Suzuki, Kimimasa Takahashi, Toshinori Sako
    Journal of Feline Medicine and Surgery Open Reports 3(1) 2055116917691175 2017年2月  査読有り
  • Y. Machida, M. Michishita, M. Wada, T. Hori, E. Kawakami, H. Yoshimura, K. Ohkusu-Tsukada, K. Taya, K. Takahashi
    JOURNAL OF COMPARATIVE PATHOLOGY 156(2-3) 178-182 2017年2月  査読有り
    A 5-year-old female domestic shorthair cat was presented with abdominal distension and serum biochemical evaluation indicated a high concentration of oestradiol (32.81 pg/ml). Exploratory laparotomy revealed a large cystic mass in the right ovary with cystic fluid containing a high level of oestradiol (18.80 pg/ml). The tumour was composed of immature neuroectodermal tissue, mature cartilage, smooth muscle, adipose tissue and aggregated, poorly differentiated mesenchymal cells. It contained cysts of various sizes that were lined by epithelium of different types. The basal layer of the lining epithelium was shown to express aromatase by immunohistochemistry. The findings suggest that this was a novel, malignant, oestrogen-secreting teratoma and that the aromatase-positive, neoplastic cells may have been the source of elevated levels of serum oestrogen. (C) 2016 Elsevier Ltd. All rights reserved.
  • Rei Nakahira, Masaki Michishita, Misaki Kato, Yuki Okuno, Hitoshi Hatakeyama, Hisashi Yoshimura, Daigo Azakami, Kazuhiko Ochiai, Makoto Bonkobara, Kimimasa Takahashi
    JOURNAL OF VETERINARY DIAGNOSTIC INVESTIGATION 29(1) 105-108 2017年1月  査読有り
    A 3-y-old male miniature Dachshund was presented with an similar to 0.8 cm diameter mass in the right mandibular region. Fourteen months later, the mass was 5 x 4 x 3 cm. Grossly, the mass was encapsulated and was homogeneously gray-white on cut surface. Microscopically, the mass was composed of large, round to polygonal tumor cells that were arranged in solid nests and cords separated by a fibrovascular stroma. Tumor cells had large, round, hypochromatic nuclei containing large prominent nucleoli and abundant eosinophilic cytoplasm containing dark blue granules visible with phosphotungstic acid-hematoxylin stain. Metastasis was observed in the mandibular lymph node. Immunohistochemically, tumor cells were positive for CK AE1/AE3, low-molecular-weight CK (CAM5.2), E-cadherin, mitochondria ATPase beta subunit, and S100, but were negative for vimentin, carcinoembryonic antigen, p63, CK14, CD10, and chromogranin A. Ultrastructurally, tumor cells contained numerous mitochondria. Therefore, the tumor was diagnosed as an oncocytic carcinoma of the mandibular gland.
  • 山本 昌美, 吉村 久志, 木村 彩友子, 市野瀬 香鈴, 神谷 新司
    日本獣医生命科学大学研究報告 (65) 34-38 2016年12月  査読有り
  • Yoko Matsuda, Toshiyuki Ishiwata, Shinichi Yachida, Akemi Suzuki, Yuri Hamashima, Hideki Hamayasu, Hisashi Yoshimura, Naoko Honma, Junko Aida, Kaiyo Takubo, Tomio Arai
    PANCREAS 45(2) 234-240 2016年2月  査読有り
    Objective The aim of the study was to investigate the clinicopathological features of pancreatic cancer at different stages using autopsy results. Methods We retrospectively evaluated 8399 consecutive cases of autopsy performed between 1972 and 2013 at our geriatric hospital. Results Macroscopic pancreatic lesions were detected in 6.13% of the cases. Primary and secondary pancreatic tumors were observed in 2.88% and 2.10% of the cases, respectively. Most primary tumors were invasive ductal adenocarcinomas (193 cases [2.31%]; mean patient age, 78.09 years) with a peak incidence at 50 to 59 years. Occult invasive ductal adenocarcinoma was discovered incidentally in 15 cases, with distant metastasis present in 26.67% of those. Microscopically, occult and advanced tumors exhibited similar characteristics such as hyalinized fibrous stroma, necrosis, invasion into vessels, peripancreatic fat tissues, and extrapancreatic nerve plexus. Mucin 1 and 2 immunohistochemical expression levels were also similar. Occult cancer incidence increased with age. Patients aged 85 years or older had shorter survival, a small tumor size, and a low incidence of lymph node metastasis. Approximately 8% of pancreatic invasive ductal adenocarcinomas progressed asymptomatically and were discovered incidentally at autopsy. Conclusions Pancreatic cancers in elderly patients tend to progress asymptomatically, but once symptoms develop, they are more often fatal than those in younger patients.
  • Yoko Matsuda, Hisashi Yoshimura, Toshiyuki Ishiwata, Hiroki Sumiyoshi, Akira Matsushita, Yoshiharu Nakamura, Junko Aida, Eiji Uchida, Kaiyo Takubo, Tomio Arai
    PANCREATOLOGY 16(1) 127-132 2016年1月  査読有り
    Objectives: Pancreatic cancer is characterized by genomic complexity and chromosomal instability, and atypical mitotic figures are morphological features of this phenotype. In the present study, we determined the frequency and the clinicopathological and prognostic significance of mitotic figures in pancreatic cancers. Methods: We surveyed the mitotic figures of the normal ductal epithelium, acinar cells, pancreatic intraepithelial neoplasias, and pancreatic cancers on hematoxylin-and-eosin stained tissue specimens (n = 121). Results: Pancreatic cancer cells showed significantly higher mitotic indices as compared with the ductal cells, acinar cells, and pancreatic intraepithelial neoplasias. Both normal and atypical mitosis were significantly elevated only in pancreatic cancers. In pancreatic cancers, approximately 30% of total mitosis was atypical including multipolar, lag-type, ring and asymmetrical mitosis, and anaphase bridges. The Kaplan-Meier curves in pancreatic cancers showed significant correlations between total mitosis and disease free survival. Furthermore, the cases with multipolar mitosis showed poorer prognosis than those without. Lymph node metastasis and multipolar mitosis were independent prognostic factors for overall survival of patients with pancreatic cancer. In addition, lymph node metastasis and total mitosis were independent factors for disease free survival. Conclusion: These findings suggest that routinely obtained pathological specimens, even small biopsy or cytological specimens, can provide valuable information concerning the prognosis of pancreatic cancers. Copyright (C) 2015, IAP and EPC. Published by Elsevier India, a division of Reed Elsevier India Pvt. Ltd. All rights reserved.
  • Yoko Matsuda, Toshiyuki Ishiwata, Hisashi Yoshimura, Satoshi Yamashita, Toshikazu Ushijima, Tomio Arai
    PANCREAS 45(1) 93-100 2016年1月  査読有り
    Objectives Nestin, a progenitor/stem cell marker, is expressed in human pancreatic cancer, where its expression correlates positively with invasiveness and metastasis. Here, we investigated the inhibition of nestin expression and the regulation of nestin expression. Methods We analyzed the effects of small interfering RNA (siRNA) targeting nestin using pancreatic cancer cell lines. Results Nestin siRNA inhibited the growth, migration, invasion, and sphere-forming ability of the pancreatic cancer cell lines. Pancreatic cancer cells cotreated with gemcitabine and nestin siRNA exhibited lower cell viability than cells treated with a control siRNA, gemcitabine alone, or nestin siRNA alone. Cells derived from the metastatic nodules of mice showed higher nestin expression than the parental cells, and nestin expression in pancreatic cancer cells was regulated by methylation of the nestin gene. In an orthotopic implantation model using mice, administration of nestin siRNA significantly decreased primary and metastatic tumor formation by human pancreatic cancer cells compared to tumor formation in control siRNA-treated mice. Conclusions Nestin plays a key role in pancreatic cancer cell metastasis and stemness and that administration of nestin siRNA may offer a novel therapeutic strategy for pancreatic cancer.
  • Hisashi Yoshimura, Yoko Matsuda, Masami Yamamoto, Tomohiko Endo, Hiroshi Kajigaya, Toshihiro Tokiwa, Toshiyuki Ishiwata, Shinji Kamiya
    JOURNAL OF NIPPON MEDICAL SCHOOL 82(6) 264-265 2015年12月  査読有り
  • H. Yoshimura, N. Kimura-Tsukada, Y. Ono, M. Michishita, K. Ohkusu-Tsukada, Y. Matsuda, T. Ishiwata, K. Takahashi
    VETERINARY PATHOLOGY 52(6) 1227-1234 2015年11月  査読有り
    Mammary tumors that spontaneously occurred in domestic Djungarian hamsters (Phodopus sungorus) were histologically examined. Forty-five mammary tumors included 14 adenomas, 18 adenocarcinomas, 1 lipid-rich carcinoma, 2 adenoacanthomas, 2 malignant adenomyoepitheliomas, 1 benign mixed tumor, and 7 balloon cell carcinosarcomas. The latter 4 types were newly recognized neoplasms in Djungarian hamsters. The relatively high incidence of spontaneous mammary carcinosarcomas in domestic Djungarian hamsters is intriguing. Carcinosarcomas exhibited anomalous histological features made up of a mixture of glandular cells, polygonal cells (including balloon cells), and sarcomatous spindle cells in varying proportions. Transitional features from glandular cells to polygonal cells and subsequently to sarcomatous spindle cells were observed. Using immunohistochemistry, we observed that glandular cells exhibited an epithelial phenotype (cytokeratin(+)/vimentin(-)), spindle cells exhibited a mesenchymal phenotype (cytokeratin(-)/vimentin(+)), and polygonal cells exhibited an intermediate phenotype (cytokeratin(+)/vimentin(+)). Reduction or loss of beta-catenin expression and gain of S100A4 expression were observed in polygonal and spindle cells. The polygonal cell population included a varying number of characteristic cells that were expanded by large intracytoplasmic vacuoles. Electron microscopy revealed that these balloon cells had large cytoplasmic lumens lined by microvilli. These observations suggest that epithelial-mesenchymal transition may account for the pathogenesis of mammary carcinosarcomas in Djungarian hamsters.
  • T. E. Kishimoto, H. Yoshimura, N. Saito, M. Michishita, N. Kanno, K. Ohkusu-Tsukada, K. Takahashi
    JOURNAL OF COMPARATIVE PATHOLOGY 153(2-3) 111-115 2015年8月  査読有り
    An 8-year-old male neutered standard dachshund was presented with a slowly growing mass in the left submandibular salivary gland. Histopathological examination revealed a tumour that was composed of bilayered duct-like structures with an inner layer of ductal cells and an outer layer of clear cells. Both inner and outer cells in the greater part of the tumour exhibited low to moderate atypia and low mitotic activity. However, a focal area towards the periphery showed enhanced cellular atypia and mitotic activity in tumour cells. Immunohistochemically, the outer layer of clear cells expressed myoepithelial markers, while the inner layer cells were positive for a luminal epithelial marker. No local recurrence or lymph node or distant metastasis was observed 18 months following surgery. Based on the morphology and immunohistochemical findings, a final diagnosis of epithelial-myoepithelial carcinoma with high-grade transformation was made. (C) 2015 Elsevier Ltd. All rights reserved.
  • Hisashi Yoshimura, Yoko Matsuda, Akira Matsushita, Yoshiharu Nakamura, Eiji Uchida, Toshiyuki Ishiwata
    JOURNAL OF NIPPON MEDICAL SCHOOL 82(3) 122-123 2015年6月  査読有り
  • R. Nakahira, M. Michishita, H. Yoshimura, H. Hatakeyama, K. Takahashi
    JOURNAL OF COMPARATIVE PATHOLOGY 152(2-3) 188-191 2015年2月  査読有り
    A 10-year-old female border collie was presented with a mass (2 cm diameter) in the fifth mammary gland. The mass was located in the subcutis and the cut surface was grey white in colour. Microscopically, the mass was composed of tumour cells arranged in nests of various sizes separated by delicate fibrovascular stroma. The tumour cells had small, round hypochromatic nuclei and abundant cytoplasm. Metastases were observed in the inguinal lymph node. Immunohistochemically, most tumour cells expressed cytokeratin (CK) 20, chromogranin A, neuron-specific enolase, synaptophysin and oestrogen receptor-beta, but not low molecular weight CK (CAM5.2), p63 and insulin. Ultrastructurally, the tumour cells contained a large number of electron-dense granules corresponding to neuroendocrine granules. Based on these findings, this case was diagnosed as a neuroendocrine carcinoma of the mammary gland. (C) 2014 Elsevier Ltd. All rights reserved.
  • Yoko Matsuda, Toshiyuki Ishiwata, Hisashi Yoshimura, Masahito Hagio, Tomio Arai
    CANCER LETTERS 357(2) 602-611 2015年2月  査読有り
    Nestin, a class VI intermediate filament, was first described as a neuronal stem/progenitor cell marker. We previously reported that knockdown of nestin expression in human glioblastoma cells suppresses cell proliferation, migration, and invasion. In the present study, we examined the effect of nestin on sternness, and identified molecules involved in modulating nestin function in glioblastoma cells. Nestin expression was shown to be higher in high-grade gliomas than in low-grade gliomas. Furthermore, compared with control cells, nestin short hairpin RNA (shRNA)-transfected glioblastoma cells exhibited reduced sphere formation, decreased expression of NANOG, N-cadherin, CD133, and Oct-4, and decreased tumor size in vivo. To examine the proteins regulated by nestin in glioblastomas, we carried out two-dimensional electrophoresis using nestin shRNA-transfected glioblastoma cells. As a result, nestin shRNA-transfected glioblastoma cells exhibited a decrease in the level of phosphorylation of heat shock cognate 71 kDa protein (HSC71; gene HSPA8). From immunoprecipitation experiments, we demonstrated the direct binding of nestin, HSC71, and cyclin D1 in vitro. Overexpression of nestin in glioblastoma cells increased cell growth, sphere formation, and cell invasion. Transfection with HSC71 siRNA restored nestin expression and cell behavior; therefore, HSC71 knockdown will interfere with enhanced tumorigenic properties of glioblastoma cells that ectopically overexpress nestin. We have demonstrated that HSC71 and nestin regulate each other's expression levels or patterns, and that cyclin D1 is located downstream of nestin and HSC71. In conclusion, nestin regulates sternness, cell growth, and invasion in glioblastoma cells through the alteration of HSC71. Inhibition of nestin and HSC71 may thus be a useful molecular target in the treatment of glioblastomas. (C) 2014 Elsevier Ireland Ltd. All rights reserved.
  • H. Yoshimura, M. Michishita, K. Ohkusu-Tsukada, Y. Matsuda, T. Ishiwata, Z. Naito, K. Takahashi
    VETERINARY PATHOLOGY 52(1) 92-96 2015年1月  査読有り
    Tenascin-C (Tn-C) is an extracellular matrix glycoprotein implicated in the progression of several human cancers. In canine mammary carcinomas, accumulation of Tn-C has been recognized in 3 different areas: regions of proliferating myoepithelial cells in complex carcinoma, basement membrane zone in low-grade simple carcinoma, and reactive stroma in high-grade simple carcinoma. To identify the Tn-C synthesizing cells in these areas, we utilized double-labeling immunohistochemistry, branched DNA in situ hybridization, and in situ hybridization-immunohistochemistry double-labeling techniques. In complex carcinomas, Tn-C was generated by proliferating myoepithelial cells. Tn-C in low-grade simple carcinomas was also derived from myoepithelial cells existing as a basal monolayer. However, stromal Tn-C in high-grade carcinomas was mainly synthesized by fibroblasts/myofibroblasts, similar to human breast cancer. Thus, the origin of Tn-C in canine mammary carcinomas differs between low- and high-grade malignancies. The role of myoepithelial cell-generated Tn-C is not yet understood.
  • H. Yoshimura, R. Nakahira, T. E. Kishimoto, M. Michishita, K. Ohkusu-Tsukada, K. Takahashi
    VETERINARY PATHOLOGY 51(6) 1090-1095 2014年11月  査読有り
    Routinely diagnosed simple solid carcinoma (SSC) of the canine mammary gland comprises a heterogeneous group of tumors. Seventy-two cases that had been diagnosed as SSC based on hematoxylin and eosin-stained tissue sections were reclassified immunohistochemically on the basis of myoepithelial markers p63 and -smooth muscle actin, as well as a luminal epithelial marker cytokeratin 8. Only 23 cases (32%) were true SSC, composed only of luminal epithelial cells, whereas 11 cases (15%) were malignant myoepithelioma (MM), composed predominantly of myoepithelial cells, and 38 cases (53%) were biphasic carcinoma (BC), characterized by biphasic proliferation of luminal epithelial and basal/myoepithelial components. As the pathological parameters were compared between the reclassified tumor types, infiltrative potential, vascular/lymphatic invasion, lymph node metastasis, and Ki-67 labeling index were higher in true SSC compared with MM and BC, suggesting that the former may exhibit a poorer prognosis compared with the latter two.

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  • 大学プレスセンター 2025年3月10日 その他
    日本獣医生命科学大学（東京都武蔵野市）獣医保健看護学科の吉村久志准教授らによる調査により新たに発見されたニホンオオカミの遺物（上顎吻端部を用いた根付）が、3月15日(土)～6月15日(日)まで国立科学博物館（東京都台東区）で開催される特別展で展示される予定。吉村准教授らは、兵庫県内の旧家に保管されていた当該遺物を形態学的および画像診断学的に解析し、その特徴を詳細に検討した。さらに、総合研究大学院大学（神奈川県三浦郡葉山町）の寺井洋平准教授がミトコンドリアDNAの解析を実施した結果、ニホンオオカミである可能性が極めて高いことが証明された。この遺物は、ニホンオオカミの遺伝学的研究を進める上で非常に貴重な事例であることから、このたび同展で公開に向けて準備が進められている。 吉村久志准教授は専門である腫瘍病理学や野生動物病理学の研究に従事する傍ら、江戸時代の馬医書の調査にも取り組んでいる。兵庫県内の旧藩の家老を務めた旧家に保管されていた馬医書を調査する過程で、同じく保管されていたイヌ科動物の上顎吻端部を用いた根付に着目した。この遺物がニホンオオカミのものである可能性を考えた吉村准教授らは、各部の計測を行うとともに、同大学 獣医放射線学研究室の藤原亜紀准教授がCT撮影を実施し、非破壊的に内部構造を観察した。 さらに、ニホンオオカミのゲノム解析を専門とする総合研究大学院大学 統合進化科学研究センターの寺井洋平准教授が、微量の骨粉からPCR法によりミトコンドリアDNAを増幅し、得られた遺伝子配列を既知のニホンオオカミの配列と照合した。 本遺物は、根付として加工するため、上顎吻端部が第２前臼歯の後方で切断されており、上顎骨と鼻骨の一部、および切歯骨のほぼ全体が残存している。現状の上顎骨長は57.9mm、上顎骨幅（犬歯位置）は41.6mmであった。右犬歯の歯冠高は26.3mmと、ニホンオオカミのものと考えて矛盾しない長さを示していた。骨の背側と切断面には黒漆、口腔側には赤漆が厚く塗られていた。また、犬歯と第１前臼歯の間の正中部には、紐穴が上顎骨から鼻骨を貫通する形で穿たれ、その紐の一端には黒漆塗りの円柱状木片が結びつけられていた。 またCT画像では、鼻腔内に正常なイヌ科動物であれば存在する鼻中隔や鼻甲介等の構造がみられず、加工時に内部構造をかき出したことが示唆されたほか、切歯根周囲の上顎骨に骨融解が認められなかったため、比較的若い個体である可能性が示された。 さらに、ミトコンドリアDNA解析では、得られた配列がニホンオオカミのものと完全に一致し、形態の測定値と併せてニホンオオカミである可能性が極めて高いことが証明された。 ニホンオオカミは20世紀初頭に絶滅したとされ、現存する剥製は国内にわずか4体のみである。一方、江戸時代から明治時代にかけて、ニホンオオカミの頭骨は病気治癒の呪具として使用され、顎骨を用いた根付は山仕事をする人々が魔除けとして身に着けていたと伝えられている。そのため、ニホンオオカミの頭骨やその一部とされる遺物は、日本各地の民家などに一定数保管されていると考えられ、形態学的にニホンオオカミと判断されたものも少なからず存在する。しかし、DNA解析によってその由来が証明された例は多くない。 今回の遺物は、根付に加工した際に骨が漆により保護されていたためか、DNAが非常に良好な状態で保存されていた。このため、ニホンオオカミの遺伝学的研究を進める上で非常に貴重な事例となる。 こうしたことから、このたび、同遺物が3月から国立科学博物館で開催される特別展「古代DNA ―日本人のきた道―」において展示される予定である。 「新発見！ニホンオオカミの遺物－イヌ科動物の上顎吻端部を用いた根付けの解析－」 吉村 久志1、鈴木 遼太郎2、藤原 亜紀3、山本 昌美1、寺井 洋平4 第５回ニチジュウシンポジウム2024（2025年2月19日） 1 獣医保健看護学応用部門 病態病理学研究分野 2 同上 大学院博士課程 3 獣医放射線学研究室 4 総合研究大学院大学 統合進化科学研究センター ◆特別展「古代DNA ―日本人のきた道―」概要 【会 期】 3月15日(土) ～ 6月15日(日) ※休館日：月曜日（月曜日が祝日の場合は火曜日）、5月7日(水) 【開館時間】 9:00～17:00（入場は16:30まで） ※ただし毎週土曜日、4月27日(日) ～ 5月6日(火・休)は19:00まで延長（入場は18:30まで）。 ※常設展示は4月26日(土) ～ 5月6日(火・休)は18:00閉館（入場は17:30まで）。それ以外の期間、常設展示は17:00閉館（入場は16:30まで）。 【場 所】 国立科学博物館（東京都台東区上野公園7-20） 【入場料】 ＜一般・大学生＞ 前売券：2,000円 当日券：2,100円 ＜小・中・高校生＞ 前売券：500円 当日券：600円 【公式サイト】 https://ancientdna2025.jp/overview ▼本件に関する問い合わせ先 研究推進課 住所： 〒180-8602 東京都武蔵野市境南町1-7-1 TEL： 0422-31-4151 FAX： 0422-33-2094 E-mail： research@nvlu.ac.jp
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