Obtained pre-clinical POC for a novel nucleic acid drug therapy targeting sarcoma

2022 Fiscal Year Final Research Report

• Project/Area Number: 22K20809
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0901:Oncology and related fields
• Research Institution: National Cancer Center Japan
• Principal Investigator: Kawachi Asuka 国立研究開発法人国立がん研究センター, 研究所, 医員 (80818162)
• Project Period (FY): 2022-08-31 – 2023-03-31
• Keywords: Oligonucleotide therapy / EWS-FLI1

Outline of Final Research Achievements

We attempted to design ASOs using two representative Ewing's sarcoma cell lines. We designed ASOs that induce Exon Skipping by targeting the Exon5 and Exon7 donor sites. 24 hours after transfection of the ASOs, RNA was isolated, and PCR was used to confirm whether Exon Skipping was generated. The amplicons obtained were wild-type only due to their size. Since the ASOs were tagged with a fluorescent dye, only fluorescent positive cells were sorted the day after transfection. Next, we designed a total of seven ASOs targeting the Exon super enhancer (ESE) and the Donor site of Exon3. However, we could not confirm that Exon skipping was induced by any of the ASOs, and the ESE sites were referred to a public database. A total of 9 different ASOs were tried, but they did not have the expected effect on EWS-FLI1. For the success of future studies, it is necessary to improve the identification of the exact ESE site and to confirm that ASOs are transferred into the nucleus.

Free Research Field

Sarcoma

Academic Significance and Societal Importance of the Research Achievements

残念ながら、今回の研究では研究の目標としたExon skippingを誘導するASO配列の同定することができなかった。実際に研究が実装された場合には、これまで治療標的が実施不可能とされてきた融合転写因子を標的とする核酸医療につながる可能性があるため、今後も研究を続ける意義があると考えられる。