Scientists have identified a signaling axis that links a specific epigenetic modification to persistent ERK/MAPK activation in glioblastoma, the aggressive brain tumor whose molecular drivers remain only partly explained. The study, published in Biology Direct, describes an SP1/P300/TRAF3IP3 pathway in which a histone acetyltransferase keeps a single cancer-relevant gene switched on, sustaining oncogenic signaling in glioblastoma cells.
The researchers report that in clinical glioma specimens spanning different WHO grades, P300 and TRAF3IP3 protein levels were positively correlated, while transcriptomic analyses showed distinct molecular subtype-dependent expression patterns for the genes EP300 and TRAF3IP3. Mechanistically, the transcription factor SP1 facilitated the recruitment of P300 to the TRAF3IP3 promoter. There, P300’s histone acetyltransferase activity maintained localized enrichment of the H3K27ac histone mark, which promoted TRAF3IP3 transcription. TRAF3IP3 then associated with MEK1 through its 240–436-amino-acid region, facilitating downstream ERK activation. When the team disrupted this MEK1-binding region, TRAF3IP3-mediated ERK phosphorylation was impaired, supporting a functional requirement for the TRAF3IP3–MEK1 interaction.
Functional rescue experiments indicated that TRAF3IP3 acts as a critical downstream mediator of P300-driven ERK signaling and of the proliferation, migration, and invasion of glioblastoma cells in laboratory models. Consistently, pharmacological inhibition of P300/CBP histone acetyltransferase activity reduced H3K27ac enrichment at the TRAF3IP3 promoter, suppressed TRAF3IP3 expression, and attenuated ERK activation. Genetic silencing of TRAF3IP3 substantially attenuated P300-driven malignant phenotypes in vitro and tumor-promoting effects in a subcutaneous xenograft model.
According to the authors, the findings delineate an SP1/P300–TRAF3IP3/MEK1–ERK regulatory cascade that connects locus-specific epigenetic remodeling with oncogenic MAPK signaling and identifies this axis as a potential therapeutic vulnerability in glioblastoma. The work is an early-access, peer-reviewed accepted article that remains subject to further edits before the final version of record. Because the reported experiments were conducted in cell models and a subcutaneous xenograft model, with clinical data limited to expression correlations across glioma grades, the results do not yet establish clinical efficacy of any intervention, and the authors frame the axis as a candidate target requiring further study rather than a validated treatment approach.
Subject of Research: Epigenetic regulation of the TRAF3IP3/ERK signaling axis in glioblastoma progression
Article Title: P300-mediated H3K27 acetylation activates the TRAF3IP3/ERK axis to promote glioblastoma progression
Article References: Lin, Q., Yu, P., Zhang, Z., Chen, X., & Yin, J. (2026). P300-mediated H3K27 acetylation activates the TRAF3IP3/ERK axis to promote glioblastoma progression. Biology Direct. https://doi.org/10.1186/s13062-026-01024-7
Image Credits: AI Generated
DOI: 10.1186/s13062-026-01024-7
Keywords: glioblastoma, P300, H3K27ac, TRAF3IP3, ERK/MAPK signaling, SP1, MEK1, histone acetylation, epigenetics, xenograft model, Biology Direct, P300-mediated
News Source: Juliet Wilcox. (October 28, 2026). Epigenetic switch drives ERK signaling in glioblastoma, study finds. Scienmag.
