449: siRNA divalente para doença priônica [PT]

Gentile JE et al., Nucleic Acids Research - Discovery and preclinical development of divalent siRNA candidates targeting PRNP, identifying 2439-s4 as a potent, durable human PRNP-lowering drug candidate with IND clearance. Key terms: prion disease, PrP lowering, divalent siRNA, 2439-s4, RNAi therapeutics.

Study Highlights:
Authors screened divalent siRNA libraries and identified mouse-targeting 1682-s4 that lowered brain PrP to ~49% and extended survival in prion-infected mice when dosed pre- or post-symptomatically. They generated human PRNP transgenic mouse lines (Tg25109, Tg26372) and nominated 2439-s4, which reduced whole-hemisphere human PrP to as low as 17% after a single dose. Mechanistic analysis showed that the s4 scaffold’s fixed 3' UU tail and exNA terminal linkages each contributed to superior potency and durability versus other scaffolds. GLP toxicology in rats and dogs found no significant adverse findings and the US FDA cleared an IND to advance 2439-s4 to clinical trials.

Conclusion:
Divalent siRNA 2439-s4 is a potent, durable PRNP-lowering candidate with favorable preclinical safety and regulatory clearance to proceed to clinical testing.

Music:
Enjoy the music based on this article at the end of the episode.

Article title:
Divalent siRNA for prion disease

First author:
Gentile JE

Journal:
Nucleic Acids Research

DOI:
10.1093/nar/gkag287

Reference:
Gentile JE, Corridon TL, Serack FE, et al. Divalent siRNA for prion disease. Nucleic Acids Research. 2026;54:gkag287. doi:10.1093/nar/gkag287

License:
This episode is based on an open-access article published under the Creative Commons Attribution 4.0 International License (CC BY 4.0) – https://creativecommons.org/licenses/by/4.0/

Support:
Base by Base is independent and ad-free — no sponsors, no paywall. If an episode was worth your time, chip in and keep the papers audited and the original songs coming:
❤️ Support monthly: https://buy.stripe.com/cNifZhclVebvagk2JDgEg01
☕ One-time donation: https://donate.stripe.com/7sY4gz71B2sN3RWac5gEg00
More at basebybase.com

On PaperCast Base by Base you'll discover the latest in genomics, functional genomics, structural genomics, and proteomics.

Episode link: https://basebybase.com/episodes/divalent-sirna-prion-disease

QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-08-24.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited transcript sections covering PRNP biology, divalent siRNA mechanism (s4 scaffold with UU tail and exNA), lead sequences (1682-s4 and 2439-s4), human PRNP transgenic mice models, intrathecal delivery, RT-qPCR and ELISA readouts, PK/PD durability, prion-infected survival data, and IND status.
- transcript topics: Prion biology and PRNP as therapeutic target; Divalent siRNA mechanism and s4 scaffold features (UU tail, exNA); Lead sequences 1682-s4 and 2439-s4 and in vivo screening; Transgenic human PRNP mice Tg25109 and Tg26372; Intrathecal delivery and brain distribution; Analytical readouts: RT-qPCR and PrP ELISA

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 6
- claims flagged for review: 0
- metadata checks passed: 4
- metadata issues found: 0

Metadata Audited:
- article_doi
- article_title
- article_journal
- license

Factual Items Audited:
- DOI canonical form 10.1093/nar/gkag287
- Article title: Divalent siRNA for prion disease
- Journal: Nucleic Acids Research
- License: Creative Commons Attribution 4.0 International License (CC BY 4.0)
- Lead sequences identified: 1682-s4 (mouse Prnp) and 2439-...