Profiling and Bioinformatics Analyses of Hypoxia-Induced Differential Expression of Long Non-coding RNA in Glioblastoma Multiforme Cells.

Abstract

Hypoxic microenvironments are intricately linked to malignant characteristics of glioblastoma multiforme (GBM). Long non-coding ribonucleic acids (lncRNAs) have been reported to be involved in the progression of GBM and closely associated with hypoxia. Nevertheless, the differential expression profiles as well as functional roles of lncRNAs in GBM cells under hypoxic conditions remain largely obscure. We explored the expression profiles of lncRNAs in hypoxic U87 cells as well as T98G cells using sequencing analysis. The effect of differentially expressed lncRNAs (DElncRNAs) was assessed through bioinformatic analysis. Furthermore, the expression of lncRNAs significantly dysregulated in both U87 and T98G cells was further validated using quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Relevant cell functional experiments were also conducted. We used predicted RNA-binding proteins (RBPs) to construct an interaction network via the interaction prediction module. U87 and T98G cells showed dysregulation of 1115 and 597 lncRNAs, respectively. Gene Ontology (GO) analysis indicated that altered lncRNA expression was associated with nucleotide-excision repair and cell metabolism in GBM cells. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed the association between dysregulated lncRNAs and the Hippo signaling pathway under hypoxia. The dysregulation of six selected lncRNAs (ENST00000371192, uc003tnq.3, ENST00000262952, ENST00000609350, ENST00000610036, and NR_046262) was validated by qRT-PCR. Investigation of lncRNA-microRNA (miRNA)-mRNA networks centered on HIF-1α demonstrated cross-talk between the six validated lncRNAs and 16 related miRNAs. Functional experiments showed the significant inhibition of GBM cell proliferation, invasion, and migration by the knockdown of uc003tnq.3 in vitro. Additionally, uc003tnq.3 was used to construct a comprehensive RBP-transcription factor (TF)-miRNA interaction network. The expression of LncRNAs was dysregulated in GBM cells under hypoxic conditions. The identified six lncRNAs might exert important effect on the development of GBM under hypoxic microenvironment.