MicroRNA expression in pediatric intracranial ependymomas and their potential value for tumor grading

Area of Science:

• Neuro-oncology
• Molecular Biology
• Cancer Research

Background:

• Intracranial ependymoma is a common pediatric brain malignancy with variable clinical behavior.
• Lack of reliable prognostic markers hinders effective patient outcome prediction.
• The role of microRNAs (miRNAs) in ependymoma pathogenesis is largely unknown.

Purpose of the Study:

• To investigate microRNA (miRNA) expression profiles in pediatric intracranial ependymoma samples.
• To identify potential miRNA biomarkers for ependymoma diagnosis and prognosis.
• To assess the impact of long-term sample storage on miRNA integrity.

Main Methods:

• Analysis of miRNA expression in 29 formalin-fixed paraffin-embedded (FFPE) pediatric intracranial ependymoma samples.
• Quantitative assessment of specific miRNA levels, including miR-135a-3p, miR-137, miR-17-5p, miR-181d, let-7d-5p, and miR-203a.
• Comparison of miRNA expression between different ependymoma grades.

Main Results:

• Upregulation of miR-135a-3p, miR-137, miR-17-5p, miR-181d, and let-7d-5p was observed in ependymoma samples.
• Significantly higher expression of miR-203a was detected in Grade III ependymomas.
• miRNA integrity was preserved in FFPE samples stored for over 20 years.

Conclusions:

• Specific miRNAs, notably miR-203a, show potential as diagnostic or prognostic markers for pediatric intracranial ependymoma.
• miRNA expression analysis can serve as a valuable adjunct to morphological assessment of ependymoma.
• Long-term FFPE sample storage does not compromise miRNA analysis, enabling retrospective studies.