Does H. pylori base-excision restriction enzyme cause stomach cancer?

• Project/Area Number: 19K22543
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 49:Pathology, infection/immunology, and related fields
• Research Institution: Hosei University (2020); Kyorin University (2019)
• Principal Investigator: Kobayashi Ichizo 法政大学, マイクロ・ナノテクノロジー研究センター, 研究員 (30126057)
• Co-Investigator(Kenkyū-buntansha): 花田 克浩 大分大学, 医学部, 助教 (90581009) ; 大崎 敬子 杏林大学, 医学部, 教授 (90255406)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000); Fiscal Year 2020: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000); Fiscal Year 2019: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
• Keywords: 胃がん / ピロリ菌 / 制限酵素 / 塩基切り出し / 変異生成 / がんゲノム / DNA切断 / DNA両鎖切断 / APエンドヌクレアーゼ / 塩基除去

Outline of Research at the Start

世界人口の半数は胃がんを起こすピロリ菌に感染しています。それがどうヒトゲノムに働いてがんを起こすのか、殆ど何も解っていません。私達は、ピロリ菌に、「特定配列DNAから塩基を切り出す」新型制限酵素を発見しました。「ピロリ菌がこの酵素をヒト細胞に注入し、それが染色体DNAの塩基を切り出し、変異・切断・ゲノム再編を起こす」という胃がんへの経路が示唆されます。その検討のために、私たちは、
A. この酵素は胃がんでのような変異を起こすかを調べます。
B. ピロリ菌感染ヒト細胞での染色体切断が、この酵素によるのかを調べます。
C. 多数のピロリ菌ゲノムを比べて、この酵素の有無が胃がんと関連するかを調べます。

Outline of Final Research Achievements

We earlier discovered base-excision restriction enzyme family and proposed that H. pylori send its family member to human cells to cause stomach cancer. We demonstrated that induction of this enzyme increases mutagenesis by one to two orders of magnitude in an E. coli mutagenesis tester strain. We demonstrated that mutations in stomach cancer are elevated at its recognition site. We demonstrated that this enzyme contributes to chromosome breakage in H. pylori-infected human cells. We demonstrated strong association between the presence of its gene and stomach cancer in H. pylori genomes. We identified amino-acid residues of diversifying selection in this genes, related them to protein 3D structure and built a 3D model for transport to human cells.

Academic Significance and Societal Importance of the Research Achievements

胃がんは，ヒトの生存に対する世界的な脅威である。その主因はピロリ菌であることは解明されたが，発がんのしくみは不明のままであった。私達は，塩基切り出し型という新しい制限酵素を発見し，「ピロリ菌が，その酵素によってヒトゲノムを作り変えることが，胃がんの原因」という仮説を提唱した。
本研究では，この仮説を支持する強い証拠を，変異生成実験，ヒト染色体切断定量，胃がんゲノムの情報解析，タンパク機能進化解析から得た。
結果は，胃がんの診療に貢献し，新薬／ワクチンで胃がんを根絶する展望を与える。「細菌によるヒトゲノム書き換え」の概念は，「マイクロバイオームとの共生体」としてのヒトと疾患の理解に新展望を開く。

Research Products

• [Int'l Joint Research] Vilnius University, Vilnius(リトアニア)
• [Int'l Joint Research] Vilnius University, Vilnius(リトアニア)
• [Int'l Joint Research] MIT(米国)
• [Journal Article] Isolation and characterization of Helicobacter suis from human stomach (2021)
  • Author(s): Rimbara Emiko、Suzuki Masato、Matsui Hidenori、Nakamura Masahiko、Morimoto Misako、Sasakawa Chihiro、Masuda Hiroki、Nomura Sachiyo、Osaki Takako、Nagata Noriyo、Shibayama Keigo、Tokunaga Kengo
  • Journal Title: Proceedings of the National Academy of Sciences Volume: 118 Issue: 13
  • DOI: 10.1073/pnas.2026337118
  • Peer Reviewed / Open Access
• [Journal Article] Analysis of Chromosomal DNA Fragmentation in Apoptosis by Pulsed-Field Gel Electrophoresis. (2020)
  • Author(s): Terabayashi T, Tokumaru A, Ishizaki T, Hanada
  • Journal Title: Methods Mol Biol. Volume: 2119 Pages: 89-99
  • DOI: 10.1007/978-1-0716-0323-9_8
  • ISBN: 9781071603222, 9781071603239
  • Peer Reviewed
• [Journal Article] Detection of DNA double-strand breaks by pulsed-field gel electrophoresis of circular bacterial chromosomes (2020)
  • Author(s): Ichizo Kobayashi, Katsuhiro Hanada
  • Journal Title: Methods in Molecular Biology (DNA Electrophoresis: Methods and Protocols) Volume: 2119 Pages: 145-154
  • DOI: 10.1007/978-1-0716-0323-9_13
  • ISBN: 9781071603222, 9781071603239
  • Peer Reviewed
• [Journal Article] Detection of Bleomycin-Induced DNA Double-Strand Breaks in Escherichia coli by Pulsed-Field Gel Electrophoresis Using a Rotating Gel Electrophoresis System (2020)
  • Author(s): Inoue Naomi、Narahara Hisashi、Nishida Yoshihiro、Hanada Katsuhiro
  • Journal Title: Methods in Molecular Biology (DNA Electrophoresis: Methods and Protocols) Volume: 2119 Pages: 155-163
  • DOI: 10.1007/978-1-0716-0323-9_14
  • ISBN: 9781071603222, 9781071603239
  • Peer Reviewed
• [Journal Article] Genome-wide association meta-analysis identifies GP2 gene risk variants for pancreatic cancer (2020)
  • Author(s): Lin Y, Nakatochi M, Hosono Y, Ito H, Kamatani Y, Inoko A, Sakamoto H, Kinoshita F, Kobayashi Y, Ishii H, Yamaji T,et al.
  • Journal Title: Nature Communications Volume: 11 Issue: 1 Pages: 3175-3175
  • DOI: 10.1038/s41467-020-16711-w
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Introduction and perspectives of DNA electrophoresis (2020)
  • Author(s): Katsuhiro Hanada
  • Journal Title: Methods in Molecular Biology (DNA Electrophoresis: Methods and Protocols) Volume: 2119 Pages: 1-13
  • DOI: 10.1007/978-1-0716-0323-9_1
  • ISBN: 9781071603222, 9781071603239
• [Presentation] 「ピロリ菌1000株ゲノム比較から現れる100の病原因子」 (2021)
  • Author(s): 小林一三
  • Organizer: 第26回日本ヘリコバクター学会学術集会
  • Invited
• [Presentation] ピロリ菌の塩基切り出し型制限酵素が胃がんを起こす？ (2019)
  • Author(s): I. Kobayashi, K. Hanada, M. Fukuyo, K. Yahara, H. Yonezawa, Ceslovas Venclovas, Y. Katsura, H. Yano, N. Takahashi, A. Toyoda, S. Nishiumi, T. Azuma, M. Kato
  • Organizer: 第78回日本癌学会学術総会
• [Presentation] Base-excising Restriction Enzymes (2019)
  • Author(s): 小林一三
  • Organizer: 第25回日本ヘリコバクター学会学術集会
• [Presentation] H. pylori base-excision restriction enzyme: an oncoprotein? (2019)
  • Author(s): I. Kobayashi, K. Hanada, M. Fukuyo, K. Yahara, H. Yonezawa, C. Venclovas, Y. Katsura, A. Toyoda, S. Nishiumi, T. Azuma, M. Kato
  • Organizer: The 32nd International Workshop of the EHMSG (European Helicobacter and Microbiota Study Group)
  • Int'l Joint Research