LncRNA HANR aggravates the malignant progression of glioma via targeting miRNA-335

FXR1 promotes glioma progression by downregulating microRNA-124-3p through long noncoding RNA FGD5-AS1 upregulation

OBJECTIVE

As reported, glioma progression is affected by altered FXR1, long non-coding RNA FGD5-AS1, and microRNA (miR)-124-3p. However, relationships among these genes remain unclear. Accordingly, this paper ascertains whether FXR1 manipulates glioma progression via the FGD5-AS1/miR-124-3p axis.

METHODS

Glioma tissues were harvested, in which FGD5-AS1 and miR-124-3p levels were examined with qRT-PCR and FXR1 level was assessed with qRT-PCR and western blot. The interaction of miR-124-3p with FGD5-AS1 was analyzed by dual-luciferase reporter, RIP, and Pearson correlation coefficient assays, and that of FXR1 with FGD5-AS1 was assessed by RIP and Pearson correlation coefficient assays. Glioma cells were obtained, followed by qRT-PCR detection of miR-124-3p expression. After gain- or loss-of-function assays, EdU, Transwell, and tubule formation assays were performed to determine cell proliferation, invasion and migration, and angiogenesis. Next, the intracranial in situ graft tumor model was established for in vivo verification.

RESULTS

FGD5-AS1 and FXR1 levels were high, but miR-124-3p level was low in glioma tissues. Likewise, glioma cells had downregulated miR-124-3p expression. Mechanistically, FGD5-AS1 negatively bound to miR-124-3p, and FXR1 was positively correlated and interacted with FGD5-AS1. miR-124-3p overexpression or FGD5-AS1 or FXR1 knockdown restricted cell invasion, proliferation, migration, and angiogenesis in gliomas. miR-124-3p inhibition abrogated the repressive impacts of FXR1 knockdown on the malignant progression of gliomas. Also, FXR1 constrained tumor growth and angiogenesis in mice, which was counterweighed by inhibiting miR-124-3p.

CONCLUSION

FXR1 might act as an oncogene in gliomas by declining miR-124-3p through FGD5-AS1.

Evolving Insights Into the Biological Function and Clinical Significance of Long Noncoding RNA in Glioblastoma

Glioblastoma (GBM) is one of the most prevalent and aggressive cancers worldwide. The overall survival period of GBM patients is only 15 months even with standard combination therapy. The absence of validated biomarkers for early diagnosis mainly accounts for worse clinical outcomes of GBM patients. Thus, there is an urgent requirement to characterize more biomarkers for the early diagnosis of GBM patients. In addition, the detailed molecular basis during GBM pathogenesis and oncogenesis is not fully understood, highlighting that it is of great significance to elucidate the molecular mechanisms of GBM initiation and development. Recently, accumulated pieces of evidence have revealed the central roles of long noncoding RNAs (lncRNAs) in the tumorigenesis and progression of GBM by binding with DNA, RNA, or protein. Targeting those oncogenic lncRNAs in GBM may be promising to develop more effective therapeutics. Furthermore, a better understanding of the biological function and underlying molecular basis of dysregulated lncRNAs in GBM initiation and development will offer new insights into GBM early diagnosis and develop novel treatments for GBM patients. Herein, this review builds on previous studies to summarize the dysregulated lncRNAs in GBM and their unique biological functions during GBM tumorigenesis and progression. In addition, new insights and challenges of lncRNA-based diagnostic and therapeutic potentials for GBM patients were also introduced.

Knockdown lncRNA DLEU1 Inhibits Gliomas Progression and Promotes Temozolomide Chemosensitivity by Regulating Autophagy

Gliomas are the most fatal malignant cerebral tumors. Temozolomide (TMZ), as the primary chemotherapy drug, has been widely used in clinics. However, resistance of TMZ still remains to poor defined. LncRNAs have been reported to play crucial roles in progression of various cancers and resistance of multiple drugs. However, the biological function and underlying mechanisms of most lncRNAs in glioma still remains unclear. Based on the TCGA database, a total of 94 differentially expressed lncRNAs, including 16 up-regulated genes and 78 downregulated genes were identified between gliomas and normal brain tissues. Subsequently, lncRNA DLEU1, HOTAIR, and LOC00132111 were tested to be significantly related to overall survival (OS) between high- and low-expression groups. Additionally, we verified that lncRNA DLEU1 was high expressed in 108 gliomas, compared with 19 normal brain tissues. And high expression of lncRNA DLEU1 predicted a poor prognosis (HR = 1.703, 95%CI: 1.133–2.917, p-value = 0.0159). Moreover, functional assays revealed that knockdown of lncRNA DLEU1 could suppress the proliferation by inducing cell cycle arrest at G1 phase and reducing the S phase by down-regulating the CyclinD1 and p-AKT, as the well as migration and invasion by inhibiting the epithelial–mesenchymal transition (EMT) markers, such as ZEB1, N-cadherin, β-catenin and snail in glioma cells. Furthermore, silencing lncRNA DLEU1 suppressed TMZ-activated autophagy via regulating the expression of P62 and LC3, and promoted sensitivity of glioma cells to TMZ by triggering apoptosis. Conclusively, our study indicated that lncRNA DLEU1 might perform as a prognostic potential target and underlying therapeutic target for sensitivity of glioma to TMZ.