Silencing of LINC00221 Suppresses Glioblastoma Cell Migration and Invasion through miR-34c-5p/Snai1 and Regulation of Actin and Cytoskeletal Dynamics Proteins

Abstract

Abstract The role of long non-coding RNAs (lncRNAs) in regulating cell motility in glioblastoma (GBM) remains largely unexplored as compared to other cancers. Our bioinformatic analyses of the microarray data of upregulated lncRNAs predicted the oncogenic role of LINC00221 in GBM cell motility. Quantitative PCR (qPCR) analysis confirmed that LINC00221 was upregulated in different GBM cell lines. While the transient silencing of LINC00221 decreased the A172 cell viability, the cell scratch closure in LN18 and T98G was suppressed. This was followed by reduced cell migration in both LN18 and T98G, but only decreased cell invasion in the latter. Furthermore, Snail and N-cadherin were only decreased in the LINC00221 silenced T98G (T98Gsi − LINC00221) but not LN18. Subsequent bioinformatic analysis predicted miR-34c-5p as a potential miRNA target downstream of LINC00221 and upstream of Snai1, which was confirmed by luciferase reporter assays. To further elucidate the molecular mechanisms involved, we identified the differentially expressed proteins (DEPs) from the proteome profiling of T98Gsi − LINC00221 and miR-34c-5p mimic transfection (T98GmiR − 34c−5p). Further enrichment of the DEPs in both T98Gsi − LINC00221 and T98GmiR − 34c−5p unveiled enriched pathways associated with the regulation of actin and cytoskeletal dynamics proteins. In summary, our findings establish the oncogenic role of LINC00221 in promoting both T98G and LN18 cell motility. Although LINC0221 exhibited the involvement of a Snai1-dependant mechanism, which is potentially modulated by miR-34c-5p in T98G, proteomic analysis further supported the regulation cell motility via the actin and cytoskeletal-related proteins following LINC00221 silencing in both GBM cells.