Summary: A study identified the protein TRNAU1AP as a key driver of glioblastoma (GBM) stem cell survival and tumor progression.
The research team demonstrated that elevated TRNAU1AP levels correlate with significantly worse clinical survival outcomes in glioblastoma patients. TRNAU1AP functions by forming intracellular liquid-like clusters that drive the synthesis of selective selenoproteins, which utilize selenium to protect cancer stem cells from oxidative damage and therapy.
The study further established that the RNA-binding protein IGF2BP3 acts as an N6-methyladenosine (m6A) reader that binds to m6A-modified TRNAU1AP mRNA, preventing its degradation and maintaining high TRNAU1AP protein expression. Blocking the IGF2BP3-TRNAU1AP signaling axis represents a promising strategy to dismantle glioblastoma stem cell resilience and enhance treatment vulnerability.
Key Facts
- Role of TRNAU1AP in Survival: Clinical tumor sample analyses and public multi-omic datasets revealed that high TRNAU1AP expression directly correlates with reduced overall survival in glioblastoma patients.
- Selenoprotein Synthesis Driver: TRNAU1AP condenses into functional intracellular clusters that facilitate the efficient translation of selective selenoproteins, which employ selenium to shield glioblastoma stem cells against cellular stress and treatment-induced damage.
- Upstream Regulation via m6A Reader IGF2BP3: The m6A reader protein IGF2BP3 binds directly to m6A-modified TRNAU1AP mRNA transcripts, enhancing transcript stability, preventing RNA degradation, and driving persistent TRNAU1AP protein overproduction.
- Cancer Stem Cell Target: Glioblastoma stem cells rely on this m6A-IGF2BP3-TRNAU1AP pathway to maintain self-renewal capacity, fuel continuous tumor growth, and resist standard therapeutic interventions.
- Therapeutic Horizon: Lead investigator Suyun Huang highlights the development of central nervous system-penetrant, small-molecule IGF2BP3 inhibitors capable of crossing the blood-brain barrier to disrupt the IGF2BP3-RNA interface and destabilize tumor-promoting transcripts.
Source: Virginia Commonwealth University
New research published in Neuro-Oncology gives a glimpse at promising discoveries that could help shape the future of glioblastoma treatment and patient outcomes.
A team of scientists from Virginia Commonwealth University, VCU Massey Comprehensive Cancer Center and the University of Texas MD Cancer Center uncovered a protein, TRNAU1AP, that plays an essential role in helping glioblastoma cells survive and multiply, along with a potential pathway to make these cancer cells more vulnerable to treatment.
“We think we could potentially target to kill this tumor,” said the lead author of the study, Suyun Huang, Ph.D., member of the Cancer Biology research program at Massey and professor in the Department of Cellular, Molecular, and Genetic Medicine at the VCU School of Medicine. “If we have a way to inhibit these proteins, it could open up new pathways to treat this deadly disease.”
About glioblastoma (GBM)
- The most aggressive type of brain tumor
- Difficult to treat because cancer stem cells keep the tumor growing and help it resist therapy
- Previously, the survival rate for glioblastoma diagnoses used to be less than one year. Now, the median survival rate is about 14 months, even with advances in treatment like brachytherapy surgery and chemotherapy.
- Relies on selenoproteins—a class of proteins important to brain development and function—for tumor progression and survival
The research findings
Through analysis of GBM tumor samples and public datasets, the research team found that TRNAU1AP plays an important role in helping cancer stem cells survive and multiply, and patients with higher levels of this protein tend to have worse survival outcomes.
TRNAUA1AP works by forming tiny clusters inside cells that help produce selective selenoproteins, which use selenium to protect cells from damage. They also discovered that another protein, IGF2BP3, helps maintain high levels of TRNAU1AP in GBM tumor cells, which suggests that blocking the IGF2BP3-TRNAU1AP pathway could make GBM cells more vulnerable and receptive to treatment.
IGF2BP3 is an m6A reader protein that recognizes the “m6A” label and protects m6A-modified mRNAs from degradation. Functioning like a molecular label, m6A is a reversible chemical modification added to mRNA that influences its fate. In GBM, IGF2BP3 binds to m6A-modified TRNAU1AP mRNA, increasing its stability and allowing production of TRNAU1AP protein to continue, which promotes tumor growth.
What’s next?
In future studies, Huang is interested in developing inhibitors of IGF2BP3 that are capable of penetrating the blood-brain barrier as a potential therapeutic strategy for GBM.
“A small-molecule inhibitor capable of entering the brain and disrupting IGF2BP3–RNA interactions could reduce the stability of these tumor-promoting transcripts and suppress glioblastoma growth,” said Huang.
Collaborators
- Additional VCU collaborators: Xiaowei Zhang, M.D., Li Li, Ph.D, Linlin Li, Ph.D., Shijun Yu, M.D., Ph.D., Taohui Ouyang, M.D., Xiao Han, Ph.D., Richard I Joh, Ph.D, and Huizhi Wang, Ph.D.
- Scientists from MD Anderson Cancer Center
This research was funded by
- Paul M. Corman, MD Chair in Cancer Research Endowment Fund
- National Center for Advancing Translational Sciences
- CCTR Endowment Fund of Virginia Commonwealth University
Key Questions Answered:
A: Glioblastoma contains a specialized subpopulation of cancer stem cells that continuously self-renew, drive tumor growth, and exhibit high resistance to conventional radiation and chemotherapy. These cells utilize specialized protection mechanisms, such as selenoprotein synthesis, to survive oxidative stress and therapeutic damage.
A: IGF2BP3 functions as an m6A reader protein. It recognizes and binds to N6-methyladenosine (m6A) chemical modifications on TRNAU1AP mRNA transcripts. This binding action shields the mRNA from natural degradation processes, ensuring high stability and continuous translation into functional TRNAU1AP protein.
A: Researchers aim to design small-molecule inhibitors that can cross the blood-brain barrier and selectively block IGF2BP3 from binding to m6A-modified RNA. Disrupting this interaction would destabilize TRNAU1AP mRNA, lower protective selenoprotein levels, and leave glioblastoma stem cells significantly more vulnerable to therapy.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this brain cancer research news
Author: Blake Belden
Source: Virginia Commonwealth University
Contact: Blake Belden – Virginia Commonwealth University
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Phase separation of TRNAU1AP protein sustains selenoprotein translation and promotes glioblastoma tumorigenesis” by Xiaowei Zhang, Li Li, Linlin Li, Shijun Yu, Taohui Ouyang, Xiao Han, Richard I. Joh, Yiwen Chen, Huizhi Wang, Suyun Huang. Neuro-Oncology
DOI:10.1093/neuonc/noag097
Abstract
Phase separation of TRNAU1AP protein sustains selenoprotein translation and promotes glioblastoma tumorigenesis
Background
Glioblastoma (GBM) depends on selenoproteins, yet the mechanisms underlying their dysregulation remain poorly understood. The tRNA-binding protein TRNAU1AP also remains largely uncharacterized, with its mechanistic functions in in vivo tumorigenesis undefined. Additionally, while IGF2BP3 is the most dysregulated N6-methyladenosine (m6A) reader in GBM, the pathways through which it promotes glioblastoma stem cell (GSC) self-renewal have yet to be elucidated.
Methods
TRNAU1AP expression in human GBMs and public datasets was analyzed by Western blotting, immunohistochemistry, and gene expression profiling. Functions of TRNAU1AP in GSCs were evaluated through gain- and loss-of-function assays assessing proliferation, self-renewal, and tumorigenicity. Proteomics, spatial transcriptomics, RNA immunoprecipitation, and polysome profiling were employed to investigate TRNAU1AP-mediated regulation of selenoprotein synthesis. RNA immunoprecipitation and phase-separation assays were used to characterize the TRNAU1AP-EEFSEC interaction. Multiomics and RNA stability analyses were performed to elucidate IGF2BP3-dependent regulation of TRNAU1AP expression.
Results
TRNAU1AP is essential for the proliferation, stemness, and tumorigenesis of GSCs and is associated with poor patient survival. TRNAU1AP interacts with EEFSEC to form a phase-separated complex that enhances EEFSEC binding to sec-tRNAsec, thereby promoting the translation of several selenoproteins. These selenoproteins act as key effectors mediating the oncogenic functions of TRNAU1AP. Furthermore, IGF2BP3 upregulates TRNAU1AP expression through m6A-dependent transcript stabilization, leading to increased selenoprotein synthesis and enhanced GSC stemness and tumorigenic potential.
Conclusion
These findings establish novel oncogenic roles of TRNAU1AP, and reveal that IGF2BP3-TRNAU1AP coupling constitutes an important mechanism for the selenoprotein synthesis and for gliomagenesis, thereby advancing the understanding of RNA-binding proteins in cancer biology.
