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Updated: Mar 20, 2026
Using the E1A Minigene Tool to Study mRNA Splicing Changes
Published on: April 22, 2021
Altered splicing leads to reduced activation of CPEB3 in high-grade gliomas
Magdalena Skubal1, Gerrit H Gielen2, Anke Waha2
1Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53105 Bonn, Germany.
Abstract:
Cytoplasmic polyadenylation element binding proteins (CPEBs) are auxiliary translational factors that associate with consensus sequences present in 3'UTRs of mRNAs, thereby activating or repressing their translation. Knowing that CPEBs are players in cell cycle regulation and cellular senescence prompted us to investigate their contribution to the molecular pathology of gliomas-most frequent of intracranial tumors found in humans. To this end, we performed methylation analyses in the promoter regions of CPEB1-4 and identified the CPEB1 gene to be hypermethylated in tumor samples. Decreased expression of CPEB1 protein in gliomas correlated with the rising grade of tumor malignancy. Abundant expression of CPEBs2-4 was observed in several glioma specimens. Interestingly, expression of CPEB3 positively correlated with tumor progression and malignancy but negatively correlated with protein phosphorylation in the alternatively spliced region. Our data suggest that loss of CPEB3 activity in high-grade gliomas is caused by expression of alternatively spliced variants lacking the B-region that overlaps with the kinase recognition site. We conclude that deregulation of CPEB proteins may be a frequent phenomenon in gliomas and occurs on the level of transcription involving epigenetic mechanism as well as on the level of mRNA splicing, which generates isoforms with compromised biological properties.
Insights
Cytoplasmic polyadenylation element binding proteins (CPEBs) are implicated in glioma. Hypermethylation of CPEB1 and altered CPEB3 splicing contribute to tumor progression and malignancy.
Area of Science:
- Neuro-oncology
- Molecular biology
- Epigenetics
Background:
- Cytoplasmic polyadenylation element binding proteins (CPEBs) regulate mRNA translation and are involved in cell cycle control and senescence.
- Gliomas are the most common primary brain tumors in humans, necessitating research into their molecular pathology.
Purpose of the Study:
- To investigate the role of CPEB1-4 in the molecular pathology of gliomas.
- To identify potential epigenetic and post-transcriptional regulatory mechanisms affecting CPEB function in gliomas.
Main Methods:
- Methylation analysis of CPEB1-4 promoter regions in glioma samples.
- Quantitative analysis of CPEB protein expression and correlation with tumor grade.
- Investigation of alternative splicing variants of CPEB3 in relation to tumor progression.
Main Results:
- CPEB1 gene hypermethylation was identified in glioma samples, correlating with decreased protein expression and higher tumor grade.
- CPEB3 expression positively correlated with glioma progression and malignancy.
- Alternative splicing of CPEB3, leading to loss of the B-region, was associated with reduced protein activity in high-grade gliomas.
Conclusions:
- Deregulation of CPEB proteins, via epigenetic mechanisms (e.g., hypermethylation) and alternative mRNA splicing, is a frequent event in gliomas.
- Altered CPEB function may contribute to glioma development and progression.
- Aberrant splicing generates CPEB isoforms with impaired biological functions, impacting glioma pathology.
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