Evidence map›Paper›PMID 42247073›Full record

ArticleJournal of neuro-oncology2026

PKA signaling modulates PRMT5/hnRNP A1-mediated IRES translation and dictates responses to mTOR inhibition in glioblastoma.

Sunil Kumar, Angelica Benavides-Serrato, Jacquelyn T Saunders, Robert N Nishimura, Joseph F Gera

Abstract read
In one paragraph

Article in Journal of neuro-oncology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Sunil KumarDepartment of Research & Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, CA, USA.
Angelica Benavides-SerratoDepartment of Research & Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, CA, USA.
Jacquelyn T SaundersDepartment of Research & Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, CA, USA.
Robert N NishimuraDepartment of Research & Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, CA, USA.
Joseph F GeraDepartment of Research & Development, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, CA, USA. jgera@mednet.ucla.edu.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionResistance to mTOR inhibitors in glioblastoma (GBM) is mediated in part by activation of internal ribosome entry site (IRES)-dependent translation, enabling continued synthesis of key cell cycle regulators. This salvage mechanism involves methylation-dependent activation of the IRES-trans-acting factor (ITAF) hnRNP A1 by PRMT5. However, the upstream regulators of this PRMT5/hnRNP A1 axis remain unclear.

methodsTo identify upstream effectors, a yeast two-hybrid screen using PRMT5 revealed PKA-Cα as an interacting partner. This interaction was validated via coimmunoprecipitation and colocalization in GBM cells. Functional relevance was assessed using biochemical, genetic, and pharmacological approaches to modulate PKA activity and examine effects on PRMT5 phosphorylation, hnRNP A1 methylation, IRES activity, and mTOR inhibitor resistance.

resultsPKA associated with PRMT5 and was activated in response to mTOR inhibition, correlating with increased cyclin D1 and c-myc mRNA IRES activity. PKA knockdown or inhibition attenuated IRES activation following mTOR inhibitor exposure. PRMT5 was phosphorylated at ser15 by PKA and this modification was required for PRMT5-hnRNP A1 interaction and downstream arginine methylation at residues R218/R225. A non-phosphorylatable PRMT5 S15A mutant failed to bind hnRNP A1, whereas a phosphomimetic S15E variant enhanced this association. PKA activation increased hnRNP A1 methylation, while combined inhibition of PKA and mTOR reduced GBM cell viability, suppressed IRES-mediated translation, and induced apoptosis both in vitro and in intracranial xenografts.

conclusionsThese findings identify a PKA/PRMT5/hnRNP A1 signaling axis that promotes IRES-dependent translation and contributes to mTOR inhibitor resistance in GBM. Dual inhibition of PKA and mTOR may represent a promising therapeutic strategy.

Indexed as

Brain NeoplasmsCyclic AMP-Dependent Protein KinasesGlioblastomaHeterogeneous Nuclear Ribonucleoprotein A1Internal Ribosome Entry SitesMTOR InhibitorsProtein-Arginine N-MethyltransferasesTOR Serine-Threonine KinasesAnimalsCell Line, TumorHumansMicePhosphorylationProtein BiosynthesisSignal TransductionCyclic AMP-Dependent Protein KinasesHeterogeneous Nuclear Ribonucleoprotein A1hnRNPA1 protein, humanInternal Ribosome Entry SitesMTOR InhibitorsMTOR protein, humanPRMT5 protein, humanProtein-Arginine N-MethyltransferasesTOR Serine-Threonine KinasesGlioblastomaHnRNP A1IRES activityMTOR inhibitionPKAPRMT5

Identifiers

PMID42247073
PMCPMC13241469

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.