Elucidation of the mechanism of mutagenesis by transient nucleobase adducts

• Project/Area Number: 19K22256
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 37:Biomolecular chemistry and related fields
• Research Institution: Osaka University
• Principal Investigator: KAWAI KIYOHIKO 大阪大学, 産業科学研究所, 准教授 (50314422)
• Co-Investigator(Kenkyū-buntansha): 小阪田 泰子 大阪大学, 産業科学研究所, 准教授 (00579245)
• Project Period (FY): 2019-06-28 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000); Fiscal Year 2020: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000); Fiscal Year 2019: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
• Keywords: DNA / 変異原 / 1分子検出 / アルコール / アセトアルデヒド / 1分子計測 / 次世代シークエンサー / 変異

Outline of Research at the Start

DNAに生じる傷は、DNAの情報が書き換わる原因となり（＝変異）、発ガン、老化を引き起こします。本研究では、DNA傷の中でも、稀にしか現れず、かつ、短い時間しか存在しないような傷（＝過渡核酸塩基付加体）に注目します。これまでは、調べる方法が無く良くわかっていなかった、過渡核酸塩基付加体が我々の発ガンや老化にどのように関わっているかを明らかにします。

Outline of Final Research Achievements

In this study, we aimed to gain insight into the formation of N2-ethylidene-G (ethG), a nucleic acid adduct transiently induced in the body by the ingestion of alcohol, a carcinogen. Using PacBio's RSII+ next-generation sequencer, we have successfully observed the formation of ethG in the presence of relatively high concentrations of acetaldehyde on the order of mM by tracking single molecules of the binding and dissociation processes of nucleic acids. The results of this study highlight the need for appropriate processing of large amounts of data in order to discuss the formation of ethG in detail and quantitatively. In order to establish a data analysis method for the formation and dissociation process of transiently formed ethG, single molecule analysis of nucleic acid aptamers was achieved.

Academic Significance and Societal Importance of the Research Achievements

百薬の長とよばれ我々の人生を豊にしている一方、国際がん研究機関より、ベンゼンなどと同じ「G1: ヒトに対する発がん性がある」に分類されているアルコールの摂取が体に与える影響を理解することは、人類がアルコールとより上手に付き合うことにつながる。我々が行ったハイスループットな1分子観測は、低頻度、かつ、短時間にしか生じない、すなわち、過渡的な準安定生成物の生成・代謝機構を調べる有効なツールとなりうることが示された。一方で、膨大なデータからのデータ抽出が必要でありAI等のデータサイエンス分野との連携が不可欠であることを浮き彫りとした。

Research Products

• [Int'l Joint Research] チューリッヒ大学(スイス)
• [Journal Article] Single-molecule Fluorescence Kinetic Sandwich Assay Using a DNA Sequencer (2022)
  • Author(s): Kawai Kiyohiko、Fujitsuka Mamoru
  • Journal Title: Chemistry Letters Volume: 51 Issue: 2 Pages: 139-141
  • DOI: 10.1246/cl.210726
  • NAID: 130008161623
  • Peer Reviewed
• [Journal Article] Control of Triplet Blinking Using Cyclooctatetraene to Access the Dynamics of Biomolecules at the Single‐Molecule Level (2021)
  • Author(s): Xu Jie、Fan Shuya、Xu Lei、Maruyama Atsushi、Fujitsuka Mamoru、Kawai Kiyohiko
  • Journal Title: Angewandte Chemie International Edition Volume: 60 Issue: 23 Pages: 12941-12948
  • DOI: 10.1002/anie.202101606
  • Peer Reviewed
• [Journal Article] Stacked Thiazole Orange Dyes in DNA Capable of Switching Emissive Behavior in Response to Structural Transitions (2021)
  • Author(s): Takada Tadao、Nishida Koma、Honda Yurika、Nakano Aoi、Nakamura Mitsunobu、Fan Shuya、Kawai Kiyohiko、Fujitsuka Mamoru、Yamana Kazushige
  • Journal Title: ChemBioChem Volume: 22 Issue: 17 Pages: 2729-2735
  • DOI: 10.1002/cbic.202100309
  • Peer Reviewed
• [Journal Article] Single-Molecule Study of Redox Reaction Kinetics by Observing Fluorescence Blinking (2021)
  • Author(s): Kawai Kiyohiko、Fujitsuka Mamoru、Maruyama Atsushi
  • Journal Title: Accounts of Chemical Research Volume: 54 Issue: 4 Pages: 1001-1010
  • DOI: 10.1021/acs.accounts.0c00754
  • Peer Reviewed
• [Journal Article] Dynamics of Single‐Stranded RNA Looping Probed and Photoregulated by Sulfonated Pyrene (2020)
  • Author(s): J. Xu, S. Tojo, M. Fujitsuka and K. Kawai
  • Journal Title: ChemistrySelect Volume: 5 Issue: 26 Pages: 8002-8008
  • DOI: 10.1002/slct.202002231
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Kinetics of Photoinduced Reactions at the Single‐Molecule Level: The KACB Method (2020)
  • Author(s): Kawai Kiyohiko、Maruyama Atsushi
  • Journal Title: Chemistry - A European Journal Volume: 26 Issue: 35 Pages: 7740-7746
  • DOI: 10.1002/chem.202000439
  • Peer Reviewed
• [Presentation] Single molecule analysis and diagnosis by measuring chemical reaction rates (2022)
  • Author(s): Kiyohiko KAWAI, Atsushi MARUYAMA, Mamoru FUJITSUKA
  • Organizer: The 25th SANKEN International Symposium
  • Int'l Joint Research / Invited
• [Presentation] DNAシーケンサーを用いたDNAアプタマーの1分子計測 (2022)
  • Author(s): 川井 清彦、藤塚 守
  • Organizer: 日本化学会第102春季年会（2022）
• [Presentation] Exploring the Dynamics of Nucleic Acids at the Single-Molecule Level Using Triplet-Triplet Energy Transfer Kinetics (2021)
  • Author(s): Jie Xu, Atsushi Maruyama, Mamoru Fujitsuka, Kiyohiko Kawai
  • Organizer: ISNAC 2021
  • Int'l Joint Research
• [Presentation] Using Triplet-Triplet Energy Transfer Kinetics to Access the Dynamics of Biomolecules at the Single-Molecule Level (2021)
  • Author(s): Jie XU, Shuya FAN, Lei XU, Atsushi MARUYAMA, Mamoru FUJITSUKA, Kiyohiko KAWAI
  • Organizer: 光化学討論会2021
• [Presentation] Single-Molecule Level Monitoring of Nucleic Acids Conformational Changes by Controlling the Fluorescence Blinking (2019)
  • Author(s): Kiyohiko Kawai
  • Organizer: π-System Figuration European-Japanese Workshop
  • Int'l Joint Research / Invited
• [Book] 核酸科学ハンドブック (2020)
  • Author(s): 日本核酸化学会、杉本 直己
  • Total Pages: 576
  • Publisher: 講談社
  • ISBN: 9784065207864