Functions of long non-coding RNA ROR in patient-derived glioblastoma cells.

Glioblastoma (GBM) is the most frequent and aggressive primary brain cancer in adult patients. A variety of long non-coding RNAs play an important role in the pathogenesis of GBM, however the molecular functions of most of them still remain elusive. Here, we investigated linc-RoR (long intergenic non-protein coding RNA, regulator of reprogramming) using GBM neurospheres obtained from 12 different patients. We demonstrated that the highest level of this transcript is detected in cells with increased EGFR expression. According to our data, linc-RoR knockdown decreases cell proliferation, increases sensitivity to DNA damage, and downregulates the level of cancer stem cell (CSC) markers. On the other hand, linc-RoR overexpression promote cell growth and increases the proportion of CSCs. Analysis of RNA sequencing data revealed that linc-RoR affects expression of genes involved in the regulation of mitosis. In agreement with this observation, we have showen that the highest level of linc-RoR is detected in the G2/M phase of the cell cycle, when linc-RoR is localized on the chromosomes of dividing cells. Based on our results, we can propose that linc-RoR performs pro-oncogenic functions in human gliobalstoma cells, which may be associated with the regulation of mitotic progression and GBM stemness.