LncRNA MATN1-AS1 prevents glioblastoma cell from proliferation and invasion via RELA regulation and MAPK signaling pathway

Shedding light on function of long non-coding RNAs (lncRNAs) in glioblastoma

The brain tumors and especially glioblastoma, are affecting life of many people worldwide and due to their high mortality and morbidity, their treatment is of importance and has gained attention in recent years. The abnormal expression of genes is commonly observed in GBM and long non-coding RNAs (lncRNAs) have demonstrated dysregulation in this tumor. LncRNAs have length more than 200 nucleotides and they have been located in cytoplasm and nucleus. The current review focuses on the role of lncRNAs in GBM. There two types of lncRNAs in GBM including tumor-promoting and tumor-suppressor lncRNAs and overexpression of oncogenic lncRNAs increases progression of GBM. LncRNAs can regulate proliferation, cell cycle arrest and metastasis of GBM cells. Wnt, STAT3 and EZH2 are among the molecular pathways affected by lncRNAs in GBM and for regulating metastasis of GBM cells, these RNA molecules mainly affect EMT mechanism. LncRNAs are involved in drug resistance and can induce resistance of GBM cells to temozolomide chemotherapy. Furthermore, lncRNAs stimulate radio-resistance in GBM cells. LncRNAs increase PD-1 expression to mediate immune evasion. LncRNAs can be considered as diagnostic and prognostic tools in GBM and researchers have developed signature from lncRNAs in GBM.

Preparation and characterization of aspirin-fucoidan complex and its admirable antitumor activity on human non-small cell lung cancer cells

The purpose of this work is to prepare a novel acetylated derivative of Undaria pinnatifida fucoidan (UPFUC) with admirable antitumor activity. Fucoidan was first acetylated by acetylsalicylic acid (aspirin, ASA) to form the ASA-UPFUC complex. The antitumor efficacy results stated that ASA-UPFUC inhibited the proliferation of human non-small cell lung cancer A549 cells in a dose-dependent manner, with an IC50 value of 49.09 μg/mL, 50.20 % lower than that of UPFUC. Importantly, the acetylation process had no adverse effects on the backbone structure of UPFUC. Simultaneously, ASA-UPFUC demonstrated a larger charge density than UPFUC, leading to enhanced solubility, improved surface charge effects, and a greater potential for exerting biological activity. Consequently, ASA-UPFUC increased the formation of alkyl and hydrogen bonds with tumor necrosis factor related apoptosis-inducing ligand receptors DR4 and DR5, thereby effectively stimulating the generation of cellular reactive oxygen species, diminishing mitochondrial membrane potential, suppressing nuclear factor κB (NFκB) p65 phosphorylation, enhancing the contents of Bax and cleaved caspase 3, and reducing the level of Bcl-2. The collective effects ultimately triggered the mitochondrial apoptotic pathway, leading to apoptosis in A549 cells. The findings support the potential utilization of ASA-UPFUC as a novel dietary additive for human lung cancer chemoprevention.

Function of Long Noncoding RNAs in Glioma Progression and Treatment Based on the Wnt/β-Catenin and PI3K/AKT Signaling Pathways

Gliomas are a deadly primary malignant tumor of the central nervous system, with glioblastoma (GBM) representing the most aggressive type. The clinical prognosis of GBM patients remains bleak despite the availability of multiple options for therapy, which has needed us to explore new therapeutic methods to face the rapid progression, short survival, and therapy resistance of glioblastomas. As the Human Genome Project advances, long noncoding RNAs (lncRNAs) have attracted the attention of researchers and clinicians in cancer research. Numerous studies have found aberrant expression of signaling pathways in glioma cells. For example, lncRNAs not only play an integral role in the drug resistance process by regulating the Wnt/β-catenin or PI3K/Akt signaling but are also involved in a variety of malignant biological behaviors such as glioma proliferation, migration, invasion, and tumor apoptosis. Therefore, the present review systematically assesses the existing research evidence on the malignant progression and drug resistance of glioma, focusing on the critical role and potential function of lncRNAs in the Wnt/β-catenin and PI3K/Akt classical pathways to promote and encourage further research in this field.

The long non-coding RNA PANDAR regulates cell proliferation and epithelial-to-mesenchymal transition in glioma

Glioma is one of the most aggressive intracranial tumors in the central nervous system. The long non-coding RNA P21 associated ncRNA DNA damage activated (PANDAR) has been reported to be an oncogene or tumor suppressor in several cancers. However, the prognostic value and biological function of PANDAR in glioma have not been described. Here, we report that expression of PANDAR is significantly up-regulated in glioma tissues and cell lines. PANDAR expression was correlated with tumor size (p=0.044) and World Health Organization (WHO) grades (p=0.005), as shown by chi-squared test. Moreover, significant upregulation of PANDAR was found to correlate with poor prognosis in glioma, as shown using Kaplan-Meier method and Cox multivariate survival analysis. Furthermore, PANDAR knockdown suppressed cell proliferation, G1/S transition, migration and invasion, and promoted apoptosis in glioma cell lines (U251 and U87). PANDAR knockdown decreased expression of CDK4, Bcl-2, N-cadherin and Vimentin, but increased E-cadherin expression in glioma cells. In conclusion, our data suggest PANDAR as a potential prognostic biomarker and therapeutic candidate for glioma.

Particulate Matters Affecting lncRNA Dysregulation and Glioblastoma Invasiveness: In Silico Applications and Current Insights

With a reported rise in global air pollution, more than 50% of the population remains exposed to toxic air pollutants in the form of particulate matters (PMs). PMs, from various sources and of varying sizes, have a significant impact on health as long-time exposure to them has seen a correlation with various health hazards and have also been determined to be carcinogenic. In addition to disrupting known cellular pathways, PMs have also been associated with lncRNA dysregulation-a factor that increases predisposition towards the onset or progression of cancer. lncRNA dysregulation is further seen to mediate glioblastoma multiforme (GBM) progression. The vast array of information regarding cancer types including GBM and its various precursors can easily be obtained via innovative in silico approaches in the form of databases such as GEO and TCGA; however, a need to obtain selective and specific information correlating anthropogenic factors and disease progression-in the case of GBM-can serve as a critical tool to filter down and target specific PMs and lncRNAs responsible for regulating key cancer hallmarks in glioblastoma. The current review article proposes an in silico approach in the form of a database that reviews current updates on correlation of PMs with lncRNA dysregulation leading to GBM progression.

Crosstalk between PI3K/AKT/mTOR and WNT/β-Catenin signaling in GBM - Could combination therapy checkmate the collusion?

Glioblastoma multiforme is one of the calamitous primary glial brain tumors with extensive heterogeneity at cellular and molecular levels. While maximal surgical resection trailed by radio and chemotherapy employing temozolomide remains the gold-standard treatment for malignant glioma patients, the overall prognosis remains dismal and there exists an unmet need for effective therapeutic strategies. In this context, we hypothesize that proper understanding of signaling pathways responsible for glioblastoma multiforme proliferation would be the first trump card while searching for novel targeted therapies. Among the pathways aberrantly activated, PI3K/AKT/mTOR is the most significant pathway, that is clinically implicated in malignancies such as high-grade glioma. Further, the WNT/β-Catenin cascade is well-implicated in several malignancies, while its role in regulating glioma pathogenesis has only emerged recently. Nevertheless, oncogenic activation of both these pathways is a frequent event in malignant glioma that facilitates tumor proliferation, stemness and chemo-resistance. Recently, it has been reported that the cross-talk of PI3K/AKT/mTOR pathway with multiple signaling pathways could promote glioma progression and reduce the sensitivity of glioma cells to the standard therapy. However, very few studies had focused on the relationship between PI3K/AKT/mTOR and WNT/β-Catenin pathways in glioblastoma multiforme. Interestingly, in homeostatic and pathologic circumstances, both these pathways depict fine modulation and are connected at multiple levels by upstream and downstream effectors. Thus, gaining deep insights on the collusion between these pathways would help in discovering unique therapeutic targets for glioblastoma multiforme management. Hence, the current review aims to address, "the importance of inter-play between PI3K/AKT/mTOR and WNT/β-Catenin pathways", and put forward, "the possibility of combinatorially targeting them", for glioblastoma multiforme treatment enhancement.

Stage-Specific Non-Coding RNA Expression Patterns during In Vitro Human B Cell Differentiation into Antibody Secreting Plasma Cells

The differentiation of B cells into antibody secreting plasma cells (PCs) is governed by a strict regulatory network that results in expression of specific transcriptomes along the activation continuum. In vitro models yielding significant numbers of PCs phenotypically identical to the in vivo state enable investigation of pathways, metabolomes, and non-coding (ncRNAs) not previously identified. The objective of our study was to characterize ncRNA expression during human B cell activation and differentiation. To achieve this, we used an in vitro system and performed RNA-seq on resting and activated B cells and PCs. Characterization of coding gene transcripts, including immunoglobulin (Ig), validated our system and also demonstrated that memory B cells preferentially differentiated into PCs. Importantly, we identified more than 980 ncRNA transcripts that are differentially expressed across the stages of activation and differentiation, some of which are known to target transcription, proliferation, cytoskeletal, autophagy and proteasome pathways. Interestingly, ncRNAs located within Ig loci may be targeting both Ig and non-Ig-related transcripts. ncRNAs associated with B cell malignancies were also identified. Taken together, this system provides a platform to study the role of specific ncRNAs in B cell differentiation and altered expression of those ncRNAs involved in B cell malignancies.

Non-Coding RNAs and Brain Tumors: Insights Into Their Roles in Apoptosis

A major terrifying ailment afflicting the humans throughout the world is brain tumor, which causes a lot of mortality among pediatric and adult solid tumors. Several major barriers to the treatment and diagnosis of the brain tumors are the specific micro-environmental and cell-intrinsic features of neural tissues. Absence of the nutrients and hypoxia trigger the cells’ mortality in the core of the tumors of humans’ brains: however, type of the cells’ mortality, including apoptosis or necrosis, has been not found obviously. Current studies have emphasized the non-coding RNAs (ncRNAs) since their crucial impacts on carcinogenesis have been discovered. Several investigations suggest the essential contribution of such molecules in the development of brain tumors and the respective roles in apoptosis. Herein, we summarize the apoptosis-related non-coding RNAs in brain tumors.

E2F transcription factor 1/small nucleolar RNA host gene 18/microRNA-338-5p/forkhead box D1: an important regulatory axis in glioma progression

This study aims to probe the biological functions of long non-coding RNA small nucleolar RNA host gene 18 (SNHG18) on glioma cells and its underlying mechanism. In this study, SNHG18 expression in glioma tissues was quantified employing GEPIA database; quantitative real-time PCR was adopted to examine the expressions of SNHG18, microRNA-338-5p (miR-338-5p) and forkhead box D1 (FOXD1) mRNA in glioma tissues and cell lines; cell proliferation, migration and invasion were detected utilizing cell counting kit-8, EdU and Transwell assays; Western blot was utilized to quantify the protein expressions of E-cadherin, N-cadherin, Vimentin and FOXD1; dual-luciferase reporter gene and RNA immunoprecipitation experiments were utilized to validate the targeting relationships between SNHG18 and miR-338-5p, as well as miR-338-5p and FOXD1 mRNA 3ʹUTR; dual-luciferase reporter gene and chromatin immunoprecipitation assays were utilized to verify the binding of E2F transcription factor 1 (E2F1) to the SNHG18 promoter region. It was revealed that, SNHG18 expression in glioma was up-regulated and associated with unfavorable prognosis of the patients; knockdown of SNHG18 repressed the malignant biological behaviors of glioma cells, enhanced E-cadherin expression and repressed N-cadherin and Vimentin expressions. MiR-338-5p was a target of SNHG18, and SNHG18 promoted the expression of FOXD1 by decoying miR-338-5p. Additionally, E2F1 could bind to the promoter of SNHG18 to elevate its expression. In conclusion, SNHG18 accelerates glioma progression via regulating the miR-338-5p/FOXD1 axis.

A System Bioinformatics Approach Predicts the Molecular Mechanism Underlying the Course of Action of Radix Salviae Reverses GBM Effects

Objective

This study used in vitro techniques to investigate the therapeutic effect of Radix Salviae on human glioblastoma and decode its underlying molecular mechanism.

Methods

The active components and targets of the Radix Salviae were identified from the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP). The targets of human glioblastoma were obtained from the GeneCards Database. The Radix Salviae-mediated antiglioblastoma was evaluated by Gene Ontology (GO) analyses and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses. Finally, mechanism of action of Radix Salviae against human glioblastoma was deduced by molecular docking and experiments.

Results

We screened 66 active ingredients and 45 targets of the Radix Salviae. The enrichment analysis based on the targets mentioned above suggested a possible role in protein phosphorylation, cell transcription, apoptosis, and inflammatory factor signaling pathways. Further study demonstrated that cryptotanshinone, an essential component of Radix Salviae, played a significant role in killing human glioblastoma cells and protecting the body by inhibiting the AKT, IKB, and STAT3 signaling pathways.

Conclusions

Radix Salviae could inhibit the proliferation and invasion of human glioblastoma by regulating STAT3, Akt, and IKB signaling pathways. Radix Salviae has potential therapeutic value in the future for human glioblastoma.

Noncoding RNAs in tumor metastasis: molecular and clinical perspectives

Metastasis is the main culprit of cancer-associated mortality and involves a complex and multistage process termed the metastatic cascade, which requires tumor cells to detach from the primary site, intravasate, disseminate in the circulation, extravasate, adapt to the foreign microenvironment, and form organ-specific colonization. Each of these processes has been already studied extensively for molecular mechanisms focused mainly on protein-coding genes. Recently, increasing evidence is pointing towards RNAs without coding potential for proteins, referred to as non-coding RNAs, as regulators in shaping cellular activity. Since those first reports, the detection and characterization of non-coding RNA have explosively thrived and greatly enriched the understanding of the molecular regulatory networks in metastasis. Moreover, a comprehensive description of ncRNA dysregulation will provide new insights into novel tools for the early detection and treatment of metastatic cancer. In this review, we focus on discussion of the emerging role of ncRNAs in governing cancer metastasis and describe step by step how ncRNAs impinge on cancer metastasis. In particular, we highlight the diagnostic and therapeutic applications of ncRNAs in metastatic cancer.

LncRNA DLGAP1-AS1 accelerates glioblastoma cell proliferation through targeting miR-515-5p/ROCK1/NFE2L1 axis and activating Wnt signaling pathway

INTRODUCTION

Glioblastoma (GBM), the primary malignant tumor in the central nervous system, features high aggressiveness and mortality. Long noncoding RNAs (lncRNAs) can exert the crucial function in regulating various human diseases, including GBM. However, the function and mechanism of lncRNA DLGAP1 antisense RNA 1 (DLGAP1-AS1) in GBM remain still unknown.

METHODS

DLGAP1-AS1 expression in GBM cells was detected by RT-qPCR. Functional assays were conducted to determine GBM cell proliferation and apoptosis. RIP, RNA pull down, and luciferase reporter assay were applied for measuring the interplay of DLGAP1-AS1 with other RNAs.

RESULTS

DLGAP1-AS1 was distinctly upregulated in GBM cells. DLGAP1-AS1 depletion inhibited cell proliferation, but induced apoptosis. MiR-515-5p could be sponged by DLGAP1-AS1 in GBM cells and to repress cell proliferation in GBM. Further, Rho-associated coiled-coil containing protein kinase 1 (ROCK1) and Nuclear factor erythroid-2 like 1 (NFE2L1) were confirmed as the target gene of miR-515-5p. Wnt signaling pathway could be activated by DLGAP1-AS1 via regulating ROCK1 and NFE2L1 expression. Rescue assays proved that overexpression of both ROCK1 and NFE2L1 could totally reverse the inhibitory effect of silencing DLGAP1-AS1 on GBM cell proliferation.

CONCLUSION

LncRNA DLGAP1-AS1 accelerated cell proliferation in GBM via targeting miR-515-5p/ROCK1/NFE2L1 axis and activating Wnt signaling pathway.

Metastasis associated long noncoding RNAs in glioblastoma: Biomarkers and therapeutic targets

Glioblastoma (GBM) is the most aggressive, malignant, and therapeutically challenging Grade IV tumor of the brain. Although the possibility of distant metastasis is extremely rare, GBM is known to cause intracranial metastasis forming aggressive secondary lesions resulting in a dismal prognosis. Metastasis also plays an important role in tumor dissemination and recurrence making GBM largely incurable. Recent studies have indicated the importance of long noncoding RNAs (lncRNAs) in GBM metastasis. lncRNAs are a class of regulatory noncoding RNAs (>200 nt) that interact with DNA, RNA, and proteins to regulate various biological processes. This is the first comprehensive review summarizing the lncRNAs associated with GBM metastasis and the underlying molecular mechanism involved in migration/invasion. We also highlight the complex network of lncRNA/miRNA/protein that collaborate/compete to regulate metastasis-associated genes. Many of these lncRNAs also show attractive potential as diagnostic/prognostic biomarkers. Finally, we discuss various therapeutic strategies and potential applications of lncRNAs as therapeutic targets for the treatment of GBM.

Long Non-Coding RNAs in Diagnosis, Treatment, Prognosis, and Progression of Glioma: A State-of-the-Art Review

Glioma is the most common malignant central nervous system tumor with significant mortality and morbidity. Despite considerable advances, the exact molecular pathways involved in tumor progression are not fully elucidated, and patients commonly face a poor prognosis. Long non-coding RNAs (lncRNAs) have recently drawn extra attention for their potential roles in different types of cancer as well as non-malignant diseases. More than 200 lncRNAs have been reported to be associated with glioma. We aimed to assess the roles of the most investigated lncRNAs in different stages of tumor progression and the mediating molecular pathways in addition to their clinical applications. lncRNAs are involved in different stages of tumor formation, invasion, and progression, including regulating the cell cycle, apoptosis, autophagy, epithelial-to-mesenchymal transition, tumor stemness, angiogenesis, the integrity of the blood-tumor-brain barrier, tumor metabolism, and immunological responses. The well-known oncogenic lncRNAs, which are upregulated in glioma, are H19, HOTAIR, PVT1, UCA1, XIST, CRNDE, FOXD2-AS1, ANRIL, HOXA11-AS, TP73-AS1, and DANCR. On the other hand, MEG3, GAS5, CCASC2, and TUSC7 are tumor suppressor lncRNAs, which are downregulated. While most studies reported oncogenic effects for MALAT1, TUG1, and NEAT1, there are some controversies regarding these lncRNAs. Expression levels of lncRNAs can be associated with tumor grade, survival, treatment response (chemotherapy drugs or radiotherapy), and overall prognosis. Moreover, circulatory levels of lncRNAs, such as MALAT1, H19, HOTAIR, NEAT1, TUG1, GAS5, LINK-A, and TUSC7, can provide non-invasive diagnostic and prognostic tools. Modulation of expression of lncRNAs using antisense oligonucleotides can lead to novel therapeutics. Notably, a profound understanding of the underlying molecular pathways involved in the function of lncRNAs is required to develop novel therapeutic targets. More investigations with large sample sizes and increased focus on in-vivo models are required to expand our understanding of the potential roles and application of lncRNAs in glioma.

Long non-coding RNAs in brain tumors: roles and potential as therapeutic targets

Brain tumors are associated with adverse outcomes despite improvements in radiation therapy, chemotherapy, and photodynamic therapy. However, treatment approaches are evolving, and new biological phenomena are being explored to identify the appropriate treatment of brain tumors. Long non-coding RNAs (lncRNAs), a type of non-coding RNA longer than 200 nucleotides, regulate gene expression at the transcriptional, post-transcriptional, and epigenetic levels and are involved in a variety of biological functions. Recent studies on lncRNAs have revealed their aberrant expression in various cancers, with distinct expression patterns associated with their instrumental roles in cancer. Abnormal expression of lncRNAs has also been identified in brain tumors. Here, we review the potential roles of lncRNAs and their biological functions in the context of brain tumors. We also summarize the current understanding of the molecular mechanisms and signaling pathways related to lncRNAs that may guide clinical trials for brain tumor therapy.

Vitamin D3 mitigates lipopolysaccharide-induced oxidative stress, tight junction damage and intestinal inflammatory response in yellow catfish, Pelteobagrus fulvidraco

The present study explored the possible mitigative effects of vitamin D₃ (VD₃) on lipopolysaccharide (LPS)-induced intestinal oxidative stress, inflammatory response and tight junction damage in yellow catfish, Pelteobagrus fulvidraco. Herein, four experimental groups were established by injecting yellow catfish with NaCl, LPS, VD₃ or LPS plus VD₃. The results showed that LPS induced oxidative stress and that exogenous VD₃ mitigated the adverse effects of LPS. Additionally, LPS suppressed the activity of antioxidant enzymes (Cat, Sod and Gr) and upregulated the mRNA expression of proinflammatory cytokines (Tnf-α, Il-1β, Il-8). Furthermore, the mRNA expression of "fencing" tight junctions (Claudin-1, Claudin-5, Occludin, Zo-1) was downregulated, while that of "pore-forming" tight junctions (Claudin-2, Claudin-12) was upregulated, however no effect on apoptosis genes was observed (p53, Bax, Caspase-3 and Caspase-9). These LPS-induced effects were significantly reversed by pretreatment with VD₃. Taken together, this study suggests that exogenous VD₃ substantially alleviates LPS-induced intestinal inflammation by upregulating antioxidant activity, suppressing inflammation and promoting fencing tight junctions in the intestine.

UBE2R2-AS1 Inhibits Xenograft Growth in Nude Mice and Correlates with a Positive Prognosis in Glioma

Our previous study showed that the lncRNA UBE2R2-AS1 inhibits the growth and invasion of glioma cells and promotes apoptosis through the miR-877-3p/TLR4 pathway. In this study, it was further found that the expression of UBE2R2-AS1 in glioma tissues was decreased significantly, and gradually decreased with increasing clinical stage. Chi-square analysis showed that the expression of UBE2R2-AS1 was significantly correlated with the WHO stage of tumor and epilepsy. Using Kaplan-Meier univariate survival analysis, it was found that the expression of UBE2R2-AS1 correlated positively with the overall survival of patients with glioma, while multiple Cox regression analysis showed that the expression of UBE2R2-AS1 correlated positively with the overall survival of patients with glioma as a protective factor for glioma prognosis. The analysis of data from TCGA also showed that patients with high UBE2R2-AS1 levels or low miR-877-3p expression were more likely to have good survival outcomes. Further construction of a glioma xenograft model in nude mice showed that UBE2R2-AS1 overexpression inhibited the growth of tumors, and the inhibition of miR-877-3p expression had a similar effect. Simultaneous UBE2R2-AS1 overexpression and miR-877-3p inhibition further decreased the growth rate of tumors in nude mice. Taken together, the results of our study suggest that UBE2R2-AS1 is an important tumor suppressor gene in glioma, which may be a good marker and treatment target for the clinical detection of glioma.

Long Noncoding RNA LINC-PINT Suppresses Cell Proliferation, Invasion, and EMT by Blocking Wnt/β-Catenin Signaling in Glioblastoma

Background: Glioblastoma (GBM) represents the most aggressive glioma with high invasive potential. Recent studies proved the involvement of epithelial-mesenchymal transition (EMT) process in increasing the malignancy and invasiveness of GBM. LncRNAs have been verified to play pivotal roles in human disease including GBM. However, the molecular mechanisms of lncRNA-mediated EMT in GBM remain largely unknown. LINC-PINT, a LncRNA which has never been studied in GBM before, was predicted to be negatively associated with EMT in GBM. This study aimed to explore the biological function and the EMT relevance of LINC-PINT in GBM and further explore the molecular mechanism.

Methods: The bioinformatic prediction data of LINC-PINT in GBM was derived from The Cancer Genome Atlas (TCGA) database by R software and GEPIA website. qRT-PCR assay was performed to detect the expression level of LINC-PINT in GBM cell lines. Cell counting kit-8 (CCK8), clone formation, transwell, and wound healing assays were performed to determine the biological function of LINC-PINT in vivo. Tumor xenograft experiment and tumor peritoneal metastasis experiments were performed to verify the in vivo function. Western blot and immunofluorescence staining assays were carried out to detect the relevance of LINC-PINT with EMT and Wnt/β-catenin signaling. Rescue assays were performed to check the regulation mechanism of LINC-PINT/Wnt signaling/EMT axis in GBM.

Results: LINC-PINT was downregulated in GBM cell lines. LINC-PINT suppressed cell progression, invasion, and EMT in GBM. LINC-PINT blocked Wnt/β-catenin signaling in GBM.

Conclusion: LINC-PINT suppressed cell proliferation, invasion, and EMT by blocking Wnt/β-catenin signaling in GBM.

Expression, Prognosis, and Immune Infiltrates Analyses of E2Fs in Human Brain and CNS Cancer

Objective

We investigated the expression patterns, potential functions, unique prognostic value, and potential therapeutic targets of E2Fs in brain and CNS cancer and tumor-infiltrating immune cell microenvironments.

Methods

We analyzed E2F mRNA expression levels in diverse cancer types via Oncomine and GEPIA databases, respectively. Moreover, we evaluated the prognostic values using GEPIA database and TCGAportal database and the correlation of E2F expression with immune infiltration and the correlation between immune cell infiltration and GBM and LGG prognosis via TIMER database. Then, cBioPortal, GeneMANIA, and DAVID databases were used for mutation analysis, PPI network analysis of coexpressed gene, and functional enrichment analysis.

Results

E2F1-8 expression increased in most cancers, including brain and CNS cancer. Higher expression in E2F1, 2, 4, 6, 7, and 8 indicated poor OS of LGG. Higher E2F3–6 and E2F1–8 expressions correlated with poor prognosis and increased immune infiltration levels in CD8+ T cells, macrophages, neutrophils, and DCs in GBM and CD8+ T cells, B cells, CD4+ T cells, neutrophils, macrophages, and DCs in LGG, respectively.

Conclusion

E2F1–8 and E2F2–8 could be hopeful prognostic biomarkers of GBM and LGG, respectively. E2F3–6 and E2F1–8 could be likely therapeutic targets in patients with immune cell infiltration of GBM and LGG, respectively.

Adsorption of miR-218 by lncRNA HOTAIR regulates PDE7A and affects glioma cell proliferation, invasion, and apoptosis

OBJECTIVE

To evaluate the role of targeted adsorption of miR-218 by long-chain non-coding RNAHOTAIR to regulate PDE7A on glioma cell proliferation, invasion, and apoptosis.

METHODS

The expressions of lncRNA HOTAIR, miR-218, and PDE7A in glioma tissues and normal parcancer tissues, NHA and glioma cell lines were determined, and correlations among the three genes were analyzed. The subcellular localization of lncRNA HOTAIR was determined by fluorescent in situ hybridization. Dual-luciferase reporter assay was used to validate the targeted relationship between lncRNA HOTAIR/miR-218/PDE7A. Glioma cells were grouped to receive intervention of lncRNA HOTAIR or miR-218. MTT, transwell, and flow cytometry were performed to determine the proliferation, invasion, and apoptosis of cells.

RESULTS

Compared with the normal tissues and cells, the expression of lncRNA HOTAIR was increased while miR-218 was suppressed in glioma tissues samples and cells (all P<0.05). Inhibition of lncRNA HOTAIR expression, was able to induce apoptosis and suppress the proliferation and invasion of cells (all P<0.05). LncRNA HOTAIR is mainly localized in the cytoplasm, and is able to adsorb miR-218 as ceRNA. The effect of knockdown of HOTAIR on glioma cells could be partially rescued by miR-218 inhibitor. The expression of PDE7A was enhanced in glioma tissues and cells compared to normal tissues and cells (all P<0.05), which positively correlated with the expression of HOTAIR (r=0.546, P<0.05) and negatively correlated with the expression of miR-218 (r=0.363, P<0.05). The targeted relationship between miR-218 and PDE7A was validated: Overexpression of miR-218 was able to suppress the proliferation and invasion of glioma cells and restrain apoptosis compared to the miR-NC group (all P<0.05). The effect of miR-218 on glioma cells could be partially rescued by PDE7A.

CONCLUSION

lncRNA HOTAIR can adsorb miR-218 to regulate expression of PDE7A and promote the malignant biologic behavior of glioma cells.

Exploring the Roles of lncRNAs in GBM Pathophysiology and Their Therapeutic Potential

Glioblastoma (GBM) remains the most devastating primary central nervous system malignancy with a median survival of around 15 months. The past decades of research have not yielded significant advancements in the treatment of GBM. In that same time, a novel class of molecules, long non-coding RNAs (lncRNAs), has been found to play a multitude of roles in cancer and normal biology. The increased accessibility of next generation sequencing technologies and the advent of lncRNA-specific microarrays have facilitated the study of lncRNA etiology. Molecular and computational methods can be applied to predict lncRNA function. LncRNAs can serve as molecular decoys, scaffolds, super-enhancers, or repressors. These molecules can serve as phenotypic switches for GBM cells at the expression and/or epigenetic levels. LncRNAs can affect stemness/differentiation, proliferation, invasion, survival, DNA damage response, and chromatin dynamics. Aberrant expression of these transcripts may facilitate therapy resistance, leading to tumor recurrence. LncRNAs could serve as novel theragnostic or prognostic biomarkers in GBM and other cancers. RNA-based therapeutics may also be employed to target lncRNAs as a novel route of treatment for primary or recurrent GBM. In this review, we explore the roles of lncRNAs in GBM pathophysiology and posit their novel therapeutic potential for GBM.

LncRNA HOXA-AS3 promotes the malignancy of glioblastoma through regulating miR-455-5p/USP3 axis

Our objective was to determine the molecular mechanisms by which lncRNA HOXA‐AS3 regulates the biological behaviour of glioblastoma multiforme (GBM). We used an lncRNA microarray assay to identify GBM‐related lncRNA expression profiles. Qrt‐PCR was used to survey the levels of expression of long non‐coding RNA (lncRNA) HOXA‐AS3 and the target gene. Dual‐luciferase reporter assays were used to investigate the interaction of lncRNA HOXA‐AS3, the target gene and miRNA. Western blot analysis was used to examine the expression of USP3 and epithelial‐mesenchymal transition (EMT) genes. The MTT assay, transwell assay and wound healing assay were used to analyse the effects of lncRNA HOXA‐AS3 on GBM cell viability, mobility and invasiveness, respectively. Our results showed that lncRNA HOXA‐AS3 was significantly up‐regulated in GBM cells and could promote GBM cell proliferation, invasion and migration in vitro and in vivo. HOXA‐AS was found to be associated with poor survival prognosis in glioma patients. The dual‐luciferase reporter assay also revealed that lncRNA HOXA‐AS3 acts as a mir‐455‐5p sponge by up‐regulating USP3 expression to promote GBM progression. Western blot analysis showed that lncRNA HOXA‐AS3 could up‐regulate EMT‐related gene expression in GBM. Experiments showed mir‐455‐5p could rescue the effect of lncRNA HOXA‐AS3 on cell proliferation and invasion. The newly identified HOXA‐AS3/mir‐455‐5p/USP3 pathway offers important clues to understanding the key mechanisms underlying the action of lncRNA HOXA‐AS3 in glioblastoma.

Long Noncoding RNA WEE2-AS1 Plays an Oncogenic Role in Glioblastoma by Functioning as a Molecular Sponge for MicroRNA-520f-3p

The long noncoding RNA WEE2 antisense RNA 1 (WEE2-AS1) plays an oncogenic role in hepatocellular carcinoma and triple negative breast cancer progression. In this study, we investigated the expression and roles of WEE2-AS1 in glioblastoma (GBM). Furthermore, the molecular mechanisms behind the oncogenic actions of WEE2-AS1 in GBM cells were explored in detail. WEE2-AS1 expression was detected using quantitative real-time polymerase chain reaction. The roles of WEE2-AS1 in GBM cells were evaluated by the cell counting kit-8 assay, flow cytometric analysis, Transwell cell migration and invasion assays, and tumor xenograft experiments. WEE2-AS1 expression was evidently enhanced in GBM tissues and cell lines compared with their normal counterparts. An increased level of WEE2-AS1 was correlated with the average tumor diameter, Karnofsky Performance Scale score, and shorter overall survival among GBM patients. Functionally, depleted WEE2-AS1 attenuated GBM cell proliferation, migration, and invasion in vitro, promoted cell apoptosis, and impaired tumor growth in vivo. Mechanistically, WEE2-AS1 functioned as a molecular sponge for microRNA-520f-3p (miR-520f-3p) and consequently increased specificity protein 1 (SP1) expression in GBM cells. A series of recovery experiments revealed that the inhibition of miR-520f-3p and upregulation of SP1 could partially abrogate the influences of WEE2-AS1 downregulation on GBM cells. In conclusion, WEE2-AS1 can adsorb miR-520f-3p to increase endogenous SP1 expression, thereby facilitating the malignancy of GBM. Therefore, targeting the WEE2-AS1–miR-520f-3p–SP1 pathway might be a promising therapy for the management of GBM in the future.

LncRNA CSMD1-1 promotes the progression of Hepatocellular Carcinoma by activating MYC signaling

Emerging evidence suggests that long non-coding RNAs (lncRNA) play critical roles in the development and progression of diverse cancers including hepatocellular carcinoma (HCC), but the underlying molecular mechanisms of lncRNAs that are involved in hepatocarcinogenesis have not been fully explored.

Methods: In this study, we profiled lncRNA expression in 127 pairs of HCC and nontumor liver tissues (a Discovery Cohort) using a custom microarray. The expression and clinical significance of lncCSMD1-1 were then validated with qRT-PCR and COX regression analysis in a Validation Cohort (n=260) and two External Validation Cohorts (n=92 and n=124, respectively). In vitro and in vivo assays were performed to explore the biological effects of lncCSMD1-1 on HCC cells. The interaction of lncCSMD1-1 with MYC was identified by RNA pull-down and RNA immunoprecipitation. The role of LncCSMD1-1 in the degradation of MYC protein was also investigated.

Results: With microarray, we identified a highly upregulated lncRNA, lncCSMD1-1, which was associated with tumor progression and poor prognosis in the Discovery Cohort, and validated in another 3 HCC cohorts. Consistently, ectopic expression of lncCSMD1-1 notably promotes cell proliferation, migration, invasion, tumor growth and metastasis of HCC cells in in vitro and in vivo experiments. Gene expression profiling on HCC cells and gene sets enrichment analysis indicated that the MYC target gene set was significantly enriched in HCC cells overexpressing lncCSMD1-1, and lncCSMD1-1 was found to directly bind to MYC protein in the nucleus of HCC cells, which resulted in the elevation of MYC protein. Mechanistically, lncCSMD1-1 interacted with MYC protein to block its ubiquitin-proteasome degradation pathway, leading to activation of its downstream target genes.

Conclusion: lncCSMD1-1 is upregulated in HCC and promotes progression of HCC by activating the MYC signaling pathway. These results provide the evidence that lncCSMD1-1 may serve as a novel prognostic marker and potential therapeutic target for HCC.

Long Non-Coding RNA SLC25A21-AS1 Promotes Multidrug Resistance in Nasopharyngeal Carcinoma by Regulating miR-324-3p/IL-6 Axis

Background

Nasopharyngeal carcinoma (NPC), one of the most common types of head and neck tumor, occurred in the epithelial lining of the nasopharynx and is mainly prevalent in Southeast Asia and Southern China. However, the molecular mechanisms of NPC multidrug resistance still remained largely unclear.

Methods

The qRT-PCR assay was performed to examine SLC25A21-AS1, miR-324-3p and IL-6 expression in NPC tissues and cell. The CCK8 assay and colony formation assay were used to detect cell growth. In addition, CCK8 assay was performed to detect IC₅₀ values of different drugs in NPC cell.

Results

In this study, we found that SLC25A21-AS1 expression was increased in NPC tissues and cell line, and knockdown of SLC25A21-AS1 inhibited cell growth and MDR in NPC cell. Moreover, SLC25A21-AS1 acted as a ceRNA for miR-324-3p and facilitates NPC cell growth and MDR by regulating the miR-324-3p/IL-6 axis.

Conclusion

Our findings demonstrated the role of SLC25A21-AS1/miR-324-3p/IL-6 axis in cell growth and MDR in NPC, which might be a potential prognostic and diagnostic marker in NPC patients and provide new insight into the molecular mechanism of MDR in NPC chemotherapy.

Current advances of long non-coding RNAs mediated by wnt signaling in glioma

Glioma is the most common and aggressive brain tumor in the central nervous system (CNS), in which Wnt signaling pathway has been verified to play a pivotal role in regulating the initiation and progression. Currently, numerous studies have indicated that long non-coding RNAs (lncRNAs) have critical functions across biological processes including cell proliferation, colony formation, migration, invasion and apoptosis via Wnt signaling pathway in glioma. This review depicts canonical and non-canonical Wnt/β-catenin signaling pathway properties and relative processing mechanisms in gliomas, and summarizes the function and regulation of lncRNAs mediated by Wnt signaling pathway in the development and progression of glioma. Ultimately, we hope to seek out promising biomarkers and reliable therapeutic targets for glioma.

SNHG7 Facilitates Glioblastoma Progression by Functioning as a Molecular Sponge for MicroRNA-449b-5p and Thereby Increasing MYCN Expression

BACKGROUND AND AIMS

Long noncoding RNA (small nucleolar RNA host gene 7) has been reported to be involved in multiple malignancies and acts as an oncogene. However, the potential mechanism of small nucleolar RNA host gene 7 in glioblastoma is rarely known. In this study, we attempted to elucidate the biological effects of small nucleolar RNA host gene 7 and the possible molecular mechanism in glioblastoma.

METHODS

The expression level of small nucleolar RNA host gene 7 in glioblastoma tissues and corresponding tumor cell lines was evaluated by using quantitative real-time polymerase chain reaction. Bioinformatics analyses and dual-luciferase reporter gene assay were conducted to verify the correlation among small nucleolar RNA host gene 7, miR-449b-5p, and MYCN. The role of small nucleolar RNA host gene 7 on cell viability, migration, and invasion was measured.

RESULTS

Small nucleolar RNA host gene 7 expression was markedly increased in glioblastoma tumor tissue. Small nucleolar RNA host gene 7 can sponge miR-449b-5p and negatively regulate miR-449b-5p expression. MiR-449b-5p was remarkably repressed in glioblastoma tissues. Reduction of miR-449b-5p reversed the repressive effects of small nucleolar RNA host gene 7 knockdown on cellular behaviors in glioblastoma. In addition, miR-449b-5p can directly bind with MYCN. Compared with normal samples, MYCN expression was increased. The MYCN expression was negatively related to miR-449b-5p expression while positively related to small nucleolar RNA host gene 7 expression. Rescue experiments revealed that MYCN overexpression reversed the repressive role of small nucleolar RNA host gene 7 knockdown on viability, migration, and invasion of U251 cells.

CONCLUSION

In summary, our results demonstrated that small nucleolar RNA host gene 7 regulates glioblastoma proliferation, migration, and invasion via regulating miR-449b-5p and its target gene MYCN, thereby providing a potential therapeutic target for glioblastoma.