Elucidating the contribution of the order of mutation acquisition to the clonal evolution of cancer using single-cell sequencing

• Project/Area Number: 20K21546
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 50:Oncology and related fields
• Research Institution: Kyoto University
• Principal Investigator: Ogawa Seishi 京都大学, 医学研究科, 教授 (60292900)
• Co-Investigator(Kenkyū-buntansha): 昆 彩奈 京都大学, 医学研究科, 助教 (20772403)
• Project Period (FY): 2020-07-30 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000); Fiscal Year 2021: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000); Fiscal Year 2020: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
• Keywords: 単一細胞シーケンス / 遺伝子変異 / クローン進化 / 白血病

Outline of Research at the Start

がんの発症における新たな変異獲得によるクローン選択の過程は、ランダムな過程ではなく、発症以前に生じた変異や環境に依存すると考えられているが、その分子論的基盤は十分に理解されていない。本研究では、代表的ながんである白血病において有意に共存しやすい組み合わせの遺伝子変異に焦点をあてて、同一の遺伝子変異の組み合わせを有するものの、変異の獲得順序の違うマウスモデルを構築する。クローン進化が観察された後に、単一細胞シーケンス技術を用いて、変異の獲得順序やクローン間相互作用がクローン進化メカニズムの過程に及ぼす影響について多角的に理解することを目指す。

Outline of Final Research Achievements

Next-generation sequencing technology have revealed a comprehensive registry of driver mutations recurrently found in MDS patients. It has also been revealed that driver mutations are acquired and positively selected in a well-organized manner to allow for expansion of the initiating clone to compromise normal hematopoiesis. To understand the molecular mechanisms underlying the clonal evolution of leukemic clones, we generated several mice models-- 1) mice with different combination of driver mutations among the four driver mutations (SRSF2, STAG2, ASXL1, RUNX1) that is frequently observed in “chromatin-spliceosome” mutated AML subtypes, 2) pre-leukemic mice models using RCAS/TVA mediated gene transfer which harbored several combinations of mutations but the order of acquisition of the mutations are different. This study elucidated the contribution of the order of mutation acquisition to the clonal evolution of cancer.

Academic Significance and Societal Importance of the Research Achievements

急性骨髄性白血病は、加齢に伴い造血幹細胞に遺伝子変異が蓄積して発症する腫瘍性疾患であり、高齢化に伴い患者数が増加している。造血幹細胞が複数の変異を獲得し、クローン選択によって高度な多様性をもった細胞集団が形成される分子メカニズムについては、発症の本質に関わる問題であるにもかかわらず、なお多くが不明である。本研究成果は、同一の遺伝子変異の組み合わせを有するものの、変異の獲得順序の違うマウスモデルを用いて、がんの発症におけるクローン選択の過程の分子病態を明らかにしたもので、将来的には、難治性がんの治療成績向上に資する可能性がある意義深い研究成果と考えている。

Research Products

• [Journal Article] Genetic basis of myelodysplastic syndromes (2020)
  • Author(s): OGAWA Seishi
  • Journal Title: Proceedings of the Japan Academy, Series B Volume: 96 Issue: 3 Pages: 107-121
  • DOI: 10.2183/pjab.96.009
  • NAID: 130007807427
  • ISSN: 0386-2208, 1349-2896
  • Year and Date: 2020-03-11
  • Peer Reviewed / Open Access
• [Journal Article] Co-mutation pattern, clonal hierarchy, and clone size concur to determine disease phenotype of SRSF2P95-mutated neoplasms (2020)
  • Author(s): Todisco Gabriele、Ogawa Seishi et al.
  • Journal Title: Leukemia Volume: - Issue: 8 Pages: 2371-2381
  • DOI: 10.1038/s41375-020-01106-z
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Single-cell analysis based dissection of clonality in myelofibrosis. (2020)
  • Author(s): Mylonas E, Yoshida K, Frick M, Hoyer K, Christen F, Kaeda J, Obenaus M, Noerenberg D, Hennch C, Chan W, Ochi Y, Shiraishi Y, Shiozawa Y, Zenz T, Oakes CC, Sawitzki B, Schwarz M, Bullinger L, le Coutre P, Rose-Zerilli MJJ, Ogawa S, Damm F.
  • Journal Title: Nat Commun. Volume: 11(1) Issue: 1 Pages: 73-73
  • DOI: 10.1038/s41467-019-13892-x
  • NAID: 120006782217
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Combined Cohesin-Runx1 Deficiency Synergistically Perturbs Chromatin Looping and Causes Myelodysplastic Syndromes (2020)
  • Author(s): Ochi Y, Ogawa Seishi., et al.
  • Journal Title: Cancer Discov Volume: - Issue: 6 Pages: 836-853
  • DOI: 10.1158/2159-8290.cd-19-0982
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] COMBINED COHESIN-RUNX1 DEFICIENCY SYNERGISTICALLY PERTURBS CHROMATIN LOOPING (2020)
  • Author(s): Yotaro Ochi, Ayana Kon, Seishi Ogawa et al.
  • Organizer: 25th Congress of EHA
  • Int'l Joint Research
• [Presentation] Functional characterization of compound DDX41 germline and somatic R525H mutations in the development of myeloid malignancies (2020)
  • Author(s): Kon A, Nakagawa MM, Inagaki R, Kataoka K, Ochi Y, Makishima H, Nakayama M, Koseki H, Nannya Y, Ogawa S
  • Organizer: 62nd ASH Annual Meeting and Exposition
  • Int'l Joint Research
• [Presentation] Distinct pathogenesis of clonal hematopoiesis revealed by single cell RNA sequencing integrated with highly sensitive genotyping method (2020)
  • Author(s): Masahiro M Nakagawa, Ryosaku Inagaki, Yutaka Kuroda, Yasuhito Nannya, Zhao Lanying, Yotaro Ochi, June Takeda, Xingxing Qi, Akinori Yoda, Ayana Kon, Nobuyuki Kakiuchi, Hideki Makishima, Shuichi Matsuda and Seishi Ogawa
  • Organizer: 62nd ASH Annual Meeting and Exposition
  • Int'l Joint Research
• [Presentation] 骨髄系腫瘍のクローン進化 (2020)
  • Author(s): Ayana Kon
  • Organizer: The 82nd Annual Meeting of the Japanese Society of Hematology
  • Int'l Joint Research