Magnetofection based on superparamagnetic iron oxide nanoparticle-mediated low lncRNA HOTAIR expression decreases the proliferation and invasion of glioma stem cells

Abstract

Glioma stem cells (GSCs) are a special subpopulation of glioma cells that are key to the sensitivity of tumors to treatments and to the possibility of tumor recurrence. Identifying new strategies that inhibit the growth of GSCs are therefore important for developing novel therapies for glioblastoma multiforme (GBM). In this study, CD133+ human glioma stem cells were isolated and cultured. Magnetic nanoparticles were used to mediate the expression of siRNAs targeting the HOTAIR (si-HOTAIR) sequence in human gliomas. Effect of downregulation of HOTAIR expression on proliferation, invasion and in vivo tumorigenicity of human GSCs and underlying molecular mechanisms were further evaluated. The results of the MTT assay and flow cytometric analysis showed that downregulation of HOTAIR expression inhibited cell proliferation and induced cell cycle arrest. Transwell assays demonstrated that downregulation of HOTAIR expression resulted in a decrease in the invasive capability of GSCs. Moreover, magnetic nanoparticle-mediated low expression of HOTAIR effectively reduced the tumorigenic capacity of glioma stem cells in vivo. In addition, the results of qRT-PCR and western blot analysis demonstrated that downregulation of HOTAIR expression significantly increased the expression of PDCD4 in GSCs, in addition to reducing the expression of CCND1 and CDK4. An in-depth mechanistic analysis showed that downregulation of HOTAIR expression reduced the recruitment of downstream molecules, EZH2 and LSD1, thereby activating the expression of PDCD4 at the transcriptional level. In conclusion, downregulation of HOTAIR expression effectively promoted the expression of PDCD4, thereby inhibiting the proliferation, invasion and in vivo tumorigenicity of human GSCs.

SPION‐mediated miR‐141 promotes the differentiation of HuAESCs into dopaminergic neuron‐like cells via suppressing lncRNA‐HOTAIR

“…We also confirmed by a variety of methods that SPIONs efficiently transduced large numbers of miR‐141 molecules into HuAESCs, which led to effective, targeted inhibition of endogenous HOTAIR expression. In view of previous reports, HOTAIR functions as a scaffold in the recruitment of PRC2 (containing EZH2, SUZ12 and EED) and the histone demethylase complex LSD1/REST (CoREST), which catalyses H3K27 methylation and H3K4 demethylation . So, the lncRNA‐HOTAIR and PRC2 then function together to inhibit the transcriptional activity of target genes .…”

“…EZH2 can keep histone H3K27 in the PDCD4 promoter region in a trimethylated state, and LSD1, as a histone deacetylase, can mediate the demethylation of H3K4me2, while the combined action of both leads to the transcriptional inhibition of PDCD4. siRNA‐mediated silencing of endogenous HOTAIR expression can reduce its recruitment of EZH2 and LSD1 proteins, which subsequently activates PDCD4 at the transcriptional level . However, in our previous studies, we used specific siRNA to silence the expression of HOTAIR.…”

“…LncRNA-HOTAIR was previously investigated in the field of long non-coding RNA. Many studies have found that lncRNA-HOTAIR regulates the transcriptional activity of target genes via the recruitment of histone (de)methylation enzymes [5][6][7][8][9]. LncRNA-HOTAIR binds to the histone 3 lysine 27 (H3K27)-specific methyltransferase complex through a motif at its 3 0 -end.…”

lncRNAs: novel players in intervertebral disc degeneration and osteoarthritis

“…Recently, several novel delivery strategies have been developed to reduce off‐target effects, especially nanoparticles that are characteristic by improved stability, extremely small size, biocompatibility and self‐assembly . Administration of HOTAIR siRNA by using magnetic nanoparticles has been shown to effectively inhibit the proliferation, invasion and in vivo tumourigenicity of human glioma stem cells . The use of nanoparticles as effective delivery vehicles for lncRNAs is thus highly attractive and deserves further studies.…”

“…145,146 Administration of HOTAIR siRNA by using magnetic nanoparticles has been shown to effectively inhibit the proliferation, invasion and in vivo tumourigenicity of human glioma stem cells. 147 The use of nanoparticles as effective delivery vehicles for lncRNAs is thus highly attractive and deserves further studies. As the pace of research in lncRNAs progresses, addressing these issues will provide opportunities for the development of novel therapeutic strategies based on targeting lncRNAs for IDD and OA.…”