296: snaR-A ncRNA antagonizes U2 snRNP SF3B2 to drive intron retention in human cells

Zhou S et al., Nature Communications, doi:10.1038/s41467-025-65448-x - snaR-A noncoding RNA interacts with U2 snRNP subunit SF3B2 and nuclear speckles, increasing intron retention and promoting proliferation in human cancer-relevant cells. Key terms: snaR-A, SF3B2, intron retention, nuclear speckles, RNA polymerase III.

Study Highlights:
Using human cell lines (HEK293T, A549, THP-1) and tumor chromatin data, the authors combined biotinylated RNA pulldown mass spectrometry, PAR-CLIP/CLIP-qPCR, HCR-RNA-FISH, TSA-seq, and ultra-deep RNA-seq (IRFinder, rMATS) to map snaR-A interactions and splicing outcomes. snaR-A directly binds splicing factors and shows nucleotide-level crosslinking to the U2 snRNP protein SF3B2, and localizes to subnuclear foci adjacent to nuclear speckles and U6-containing sites. Functionally, snaR-A overexpression increases intron retention and selectively depletes SF3B2 protein, whereas snaR-A depletion reduces intron retention for transcripts with high U2 occupancy and speckle proximity. These splicing changes alter protein abundance for multiple targets and coincide with reduced proliferation after snaR-A depletion, consistent with tumor-level associations to growth.

Conclusion:
snaR-A acts as a molecular antagonist of U2-dependent splicing by interacting with SF3B2 and perturbing processing of specific mRNA subpopulations, promoting intron retention and proliferation in cancer-relevant contexts.

Music:
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Article title:
Cancer-associated snaR-A noncoding RNA interacts with core splicing machinery and disrupts processing of mRNA subpopulations

First author:
Zhou S

Journal:
Nature Communications, doi:10.1038/s41467-025-65448-x

DOI:
10.1038/s41467-025-65448-x

Reference:
Zhou S., Lizarazo S., Chorghade S., Mouli L., Cheng R., Rajendra K. C., Kalsotra A., Van Bortle K. Cancer-associated snaR-A noncoding RNA interacts with core splicing machinery and disrupts processing of mRNA subpopulations. Nature Communications. 2025;16:10460. https://doi.org/10.1038/s41467-025-65448-x

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/

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QC:
This episode was checked against the original article PDF and publication metadata for the episode release published on 2026-02-21.

QC Scope:
- article metadata and core scientific claims from the narration
- excludes analogies, intro/outro, and music
- transcript coverage: Audited the transcript’s presentation of the snaR-A study: interaction with SF3B2 and U2 snRNP, localization to nuclear speckles, intron retention effects, SF3B2 protein depletion, depletion effects on splicing and protein abundance, proliferation/migration phenotypes, TCGA prognosis, and limitations.
- transcript topics: snaR-A interaction with SF3B2 and U2 snRNP; localization of snaR-A to nuclear speckles and proximity to U6; snaR-A-induced intron retention and splicing disruption; SF3B2 protein depletion upon snaR-A overexpression; snaR-A depletion reduces IR in U2-residency, speckle-proximal transcripts; OGFR and other targets affected by splicing changes

QC Summary:
- factual score: 10/10
- metadata score: 10/10
- supported core claims: 7
- 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:
- snaR-A ncRNA interacts with SF3B2, a core U2 snRNP component
- snaR-A localizes to subnuclear foci near nuclear speckles and U6
- overexpression of snaR-A increases intron retention (IR)
- snaR-A overexpression reduces SF3B2 protein levels
- snaR-A depletion reduces IR for transcripts with high U2 residency and speckle proximity
- splicing changes lead to altered protein abundance for targets including OGFR

QC result: Pass.