Abstract 3575: Dysregulated expression of lncRNAs in glioblastoma multiforme and their association with overall survival
Authors: Vecera Marek , Oppelt Jan , Radova Lenka , Lipina Radim , Reguli Stefan , Smrcka Martin , Jancalek Radim , Filip Michal , Hermanova Marketa , Kren Leos , Sana Jiri , Kopkova Alena , Kovacova Julia , Slaby Ondrej 
Published: August 2019

Abstract
Introduction: Glioblastoma multiforme (GBM) is the most frequent primary brain malignancy of astrocytic origin. The prognosis remains very poor with the median overall survival (OS) being between 12 and 16 months from diagnosis despite early use of conventional medical therapy. Identifying new therapeutic targets, as well as prognostic and predictive biomarkers for accurate stratification of patients is therefore of utmost importance. Long non-coding RNAs (lncRNAs) are regulators of gene expression having critical impact on both physiological processes and the molecular pathology of GBM, indicating their potential as biomarkers and therapeutic targets.
Material and Methods: Our study included 219 GBM patients and 29 patients with non-dominant anterior temporal cortexes resected during surgery for intractable epilepsy. Informed consent approved by the local Ethical Commission was obtained from each patient. RNA (RIN &gt; 8) from 77 specimens was used for next-generation RNA sequencing (RNAseq). rRNA depletion and cDNA library preparation were done with RiboCop rRNA Depletion Kit V1.2 (Lexogen) and NEBNext Ultra II Directional RNA Library Prep Kit for Illumina (NEB), respectively. RNAseq was performed using NextSeq 500 High Output Kit and NextSeq 500 instrument (both Illumina). 8,414 lncRNAs and their sequential variants with non-zero RPKM at least in one sample were statistically evaluated. The alignment and target counts were performed with CLC genomic workbench. Selected significantly dysregulated lncRNAs between GBM and non-tumor controls were analyzed in a larger cohort of 188 specimens by qRT-PCR and the expression data normalized to PPIA was then evaluated by Mann-Whitney U test.
Results: Statistical analysis revealed 538 (P &lt; 0.001) dysregulated lncRNAs in GBMs compared to non-tumor brain tissue samples. The expression of top 10 downregulated lncRNAs (SNAI3-AS1, LINC00882, RFPL1S, MIR137HG, TTLL7-IT1, PWAR6, LINC00634, LINC00632, DGCR5, LINC00982; logFC ≤ -2; P &lt; 0.001) and 1 upregulated lncRNA (BTN2A3P; logFC ≥ 2; P &lt; 0.001) in GBM and non-tumor controls was successfully validated by qRT-PCR (P &lt; 0.0001). Moreover, the statistical analysis revealed 22 lncRNAs significantly dysregulated between patients with OS less than 12 months and those with OS equal or more than 12 months (P &lt; 0.01).
Conclusion: We observed significant dysregulation of lncRNAs in GBM tissues compared to non-tumor controls based on the results of both RNASeq and qRT-PCR. We also found 22 lncRNAs to be dysregulated in relation to overall survival. Our study indicates that lncRNAs could serve as promising diagnostic and prognostic biomarkers in GBM. This work was supported by Ministry of Health of the Czech Republic grant nr. NV18-03-00398, grant of Czech Grant Agency nr. 17-17636S, and by the Ministry of Education, Youth and Sports of the Czech Republic under the project CEITEC 2020 (LQ1601).
Citation Format: Marek Vecera, Jan Oppelt, Lenka Radova, Radim Lipina, Stefan Reguli, Martin Smrcka, Radim Jancalek, Michal Filip, Marketa Hermanova, Leos Kren, Jiri Sana, Alena Kopkova, Julia Kovacova, Ondrej Slaby. Dysregulated expression of lncRNAs in glioblastoma multiforme and their association with overall survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3575.