Abstract
Glioblastoma is one of the most frequent primary brain tumors with a poor prognosis. Nevertheless, some patients show a prolonged survival. The aim of the present study was to compare the expression profiles of tumor derived microRNA (miR) of long‑term survivors with those of short‑term survivors in order to identify differentially expressed miRs as well as their target genes, which may elucidate mechanisms that play a role in varying tumor progression and, therefore, may influence survival. Formalin‑fixed paraffin‑embedded samples of 23 patients with glioblastoma were classified according to overall survival. Profiles of miR expression were determined using Nanostring technology. Expression levels of potential target genes of differentially expressed miRs were assessed using immunohistochemistry. MiR profiles of long‑term survivors differed from those of short‑term survivors. A total of three prominent differentially expressed miRs were highlighted: MiR‑130b‑3p, which is downregulated in long‑term survivors, and miR‑146b‑5p and miR‑148a‑3p, which are upregulated in long‑term survivors. Known tumor suppressor genes are among targets potentially affected by miR‑130b‑3p, whereas targets of miR‑146b‑5p and miR‑148a‑3p consist of several genes known to have a role in tumor invasion and aggressiveness. In conclusion, it was revealed that a type of miR‑signature was associated with short‑ and long‑term survival, potentially serving as biomarker for disease progression and providing a base for further functional studies.