Comprehensive analysis of microRNA expression profile in malignant glioma tissues

Abstract

Malignant gliomas represent the most devastating group of brain tumors in adults, among which glioblastoma multiforme (GBM) exhibits the highest malignancy rate. Despite combined modality treatment, GBM recurs and is invariably fatal. A further insight into the molecular background of gliomagenesis is required to improve patient outcomes. The primary aim of this study was to gain broad information on the miRNA expression pattern in malignant gliomas, mainly GBM. We investigated the global miRNA profile of malignant glioma tissues with miRNA microarrays, deep sequencing and meta-analysis. We selected miRNAs that were most frequently deregulated in glioblastoma tissues, as well as in peritumoral areas, in comparison with normal human brain. We identified candidate miRNAs associated with the progression from glioma grade III to glioma grade IV. The meta-analysis of miRNA profiling studies in GBM tissues summarizes the past and recent advances in the investigation of the miRNA signature in GBM versus noncancerous human brain and provides a comprehensive overview. We propose a list of 35 miRNAs whose expression is most frequently deregulated in GBM patients and of 30 miRNA candidates recognized as novel GBM biomarkers.

miRNA targeting and alternative splicing in the stress response – events hosted by membrane-less compartments

“…Therefore, it is critical to understand how their expression is controlled -especially under stress conditions. miRNAs are prime candidates to control gene expression, as the miRNA expression profile is substantially changed in response to different stresses or diseases (Emde et al, 2015;Freiesleben et al, 2016;Lu et al, 2005;Marrone et al, 2012;Piwecka et al, 2015). This change in miRNA expression has a profound impact on the ability of the cell, or even the whole organism, to manage stress responses (Cicek et al, 2016;Edeleva and Shcherbata, 2013;Leung and Sharp, 2010;Mori et al, 2012).…”

MicroRNAs as efficient biomarkers in high-grade gliomas

“…Some studies show lower miRNA expression in tumour samples, what can be a function of cellular differentiation status [38]. Microarray studies of glioma tissue have implicated a number of miRNAs involved in glioma formation and propagation [47]. However, a comprehensive set of these differentially expressed RNA species has not been produced.…”

“…However, a comprehensive set of these differentially expressed RNA species has not been produced. Our group, based on miRNA micro array data analysis and deep RNA sequencing of miRNAs in normal human brain and tumour tissue, has recently found several RNA signatures, which were complemented with meta-analysis [47].…”

“…There were 22 differentially expressed miRNAs when comparing normal brain and brain tumour adjacent tissue [47]. The analysis revealed 6 miRNAs with elevated expression and 16 miRNAs with low expression within the tumour borders.…”

“…Although many potentially useful probes have already been suggested, no such markers have been established for brain tumours. In this review several specific microRNA biomarkers will be presented and discussed, including those identified by our group [47].…”