Survey of MicroRNA Expression in Pediatric Brain Tumors

Background. A better understanding of pediatric brain tumor biology is needed to assist in the development of less toxic therapies and to provide better markers for disease stratification. MicroRNAs (miRNA) may play a significant role in brain tumor biology. The present study provides an initial survey of miRNA expression in pediatric central nervous system (CNS) malignancies including atypical teratoid/rhabdoid tumor, ependymoma, glioblastoma, medulloblastoma, and pilocytic astrocytoma. Procedure. MicroRNA expression in pediatric brain tumors and normal tissue controls was examined by microarray. Three aberrantly expressed miRNAs were further studied in a larger cohort by quantitative real-time PCR (qRT-PCR). Results. MicroRNA-129, miR-142-5p, and miR-25 were differentially expressed in every pediatric brain tumor type compared to normal tissue controls as measured by microarray. When further examined by qRT-PCR, these miRNAs demonstrated differential expression that significantly correlated with the microarray findings. Distinctive miRNA expression profiles were also observed in the different pediatric brain tumor types. Conclusions. MicroRNAs are differentially expressed between pediatric CNS neoplasms and normal tissue suggesting that they may play a significant role in oncogenesis. A greater understanding of aberrant miRNA expression in pediatric brain tumors may aid in the development of novel therapies. The characterization of tumor-specific miRNA signatures may aid in the discovery of biomarkers with diagnostic or prognostic utility. Pediatr Blood Cancer 2011;56:211-216. (C) 2010 Wiley-Liss, Inc.