Identification of microRNAs differentially expressed in glioblastoma stem-like cells and their association with patient survival

Lenka Radova,Jiri Sana,Martin Smrcka,Marek Hilser,Radim Lipina,Petr Busek,Ondrej Slaby,Marek Vecera,Leos Kren,Lucie Stollinova Sromova,Andrej Besse,Stefan Reguli,Radek Lakomy,Pavel Fadrus,Aleksi Sedo

doi:10.1038/s41598-018-20929-6

Abstract

Glioblastoma stem-like cells (GSCs) are critical for the aggressiveness and progression of glioblastoma (GBM) and contribute to its resistance to adjuvant treatment. MicroRNAs (miRNAs) are small, non-coding RNAs controlling gene expression at the post-transcriptional level, which are known to be important regulators of the stem-like features. Moreover, miRNAs have been previously proved to be promising diagnostic biomarkers in several cancers including GBM. Using global expression analysis of miRNAs in 10 paired in-vitro as well as in-vivo characterized primary GSC and non-stem glioblastoma cultures, we identified a miRNA signature associated with the stem-like phenotype in GBM. 51 most deregulated miRNAs classified the cell cultures into GSC and non-stem cell clusters and identified a subgroup of GSC cultures with more pronounced stem-cell characteristics. The importance of the identified miRNA signature was further supported by demonstrating that a Risk Score based on the expression of seven miRNAs overexpressed in GSC predicted overall survival in GBM patients in the TCGA dataset independently of the IDH1 status. In summary, we identified miRNAs differentially expressed in GSCs and described their association with GBM patient survival. We propose that these miRNAs participate on GSC features and could represent helpful prognostic markers and potential therapeutic targets in GBM.

Highlights

Glioblastoma stem-like cells (GSCs) are critical for the aggressiveness and progression of glioblastoma (GBM) and contribute to its resistance to adjuvant treatment
We successfully derived paired primary cell cultures from several Glioblastoma multiforme (GBM) (8 men and 2 women; median age 64 years - min 52, max 78 years), which were propagated in both defined serum-free medium favoring the expansion of GSCs and in medium supplemented with 10% FBS
Glioblastoma multiforme (GBM), the most common malignant primary brain tumor arising from glial cells, is associated with fatal prognosis caused by its localization in the central nervous system, but especially by the high invasiveness and resistance to conventional therapies

Summary

Introduction

Glioblastoma stem-like cells (GSCs) are critical for the aggressiveness and progression of glioblastoma (GBM) and contribute to its resistance to adjuvant treatment. Glioblastoma stem-like cells (GSCs) are thought to be an important contributor to the poor response to the adjuvant therapy due to the higher expressions of the DNA repair enzymes, antiapoptotic factors, and multidrug transporters[2,3]. These rather slow proliferating cells are capable of self -renewal and multilineage differentiation, are highly invasive, modulate immune response and promote angiogenesis. We further corroborated the importance of the most differentially expressed miRNAs by showing their potential to predict overall survival in GBM patients independently of the IDH1 mutation status

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Conclusion