An Insight into the Increasing Role of LncRNAs in the Pathogenesis of Gliomas

Exosomal long non-coding RNAs in cancer: Interplay, modulation, and therapeutic avenues

In the intricate field of cancer biology, researchers are increasingly intrigued by the emerging role of exosomal long non-coding RNAs (lncRNAs) due to their multifaceted interactions, complex modulation mechanisms, and potential therapeutic applications. These exosomal lncRNAs, carried within extracellular vesicles, play a vital partin tumorigenesis and disease progression by facilitating communication networks between tumor cells and their local microenvironment, making them an ideal candidates for use in a liquid biopsy approach. However, exosomal lncRNAs remain an understudied area, especially in cancer biology. Therefore this review aims to comprehensively explore the dynamic interplay between exosomal lncRNAs and various cellular components, including interactions with tumor-stroma, immune modulation, and drug resistance mechanisms. Understanding the regulatory functions of exosomal lncRNAs in these processes can potentially unveil novel diagnostic markers and therapeutic targets for cancer. Additionally, the emergence of RNA-based therapeutics presents exciting opportunities for targeting exosomal lncRNAs, offering innovative strategies to combat cancer progression and improve treatment outcomes. Thus, this review provides insights into the current understanding of exosomal lncRNAs in cancer biology, highlighting their crucial roles, regulatory mechanisms, and the evolving landscape of therapeutic interventions. Furthermore, we have also discussed the advantage of exosomes as therapeutic carriers of lncRNAs for the development of personalized targeted therapy for cancer patients.

Clinical significance of lncRNA XIST expression in cholangiocarcinoma and its effect on cell migration and invasion

BACKGROUND

Cholangiocarcinoma is a malignant tumor that occurs in the bile duct system, and the prognosis of patients is poor. Currently, research suggests that long non-coding RNAs (lncRNAs) in the treatment and prevention of cholangiocarcinoma. This study primarily focuses on the regulation and potential mechanism of the lncRNA XIST (XIST) in cholangiocarcinoma.

METHODS

The levels of XIST and miR-126-3p in cholangiocarcinoma tissues and cells were detected using real-time quantitative polymerase chain reaction (RT-qPCR). Cell transfection status, including migration and invasion, was examined via the Transwell method. The relationship between XIST and miR-126-3p was observed by dual-luciferase gene reporter assay and verified by rescue assays. Additionally, the prognostic significance of XIST in cholangiocarcinoma was determined using Kaplan-Meier and multivariate Cox regression analyses.

RESULTS

XIST expression was increased in cholangiocarcinoma, while miR-126-3p was decreased, in both tissues and cells. The successful construction of silencing XIST was found to inhibit the count of cell migration and invasion. XIST directly targeted miR-126-3p to regulate the progression of cholangiocarcinoma.

CONCLUSION

XIST sponging miR-126-3p inhibited the progression of cholangiocarcinoma and improved the prognosis for patients. This finding provides new insights and opportunities for future studies on cholangiocarcinoma prognostic biomarkers.

Roles of AFAP1-AS1 in Gynecology and Urogenital System

BACKGROUND

Human disease onset and progression are strongly associated with aberrant long noncoding RNA (lncRNA) expression, highlighting the functional regulatory role of lncRNA. Actin filament-associated protein 1-antisense RNA 1 (AFAP1-AS1), a member of lncRNAs, is located on the antisense strand of Actin filament-associated protein 1 (AFAP1).

METHODS

We conducted a comprehensive review of AFAP1-AS1's functions in gynecology and urogenital systems using the "PubMed" database.

RESULTS

Our analysis reveals that AFAP1-AS1 is overexpressed and engages in the initiation and process of gynecological and urogenital diseases. The regulatory mechanisms employed by AFAP1-AS1 involve four major strategies: gene-level effects, competition for microRNA (miRNA) repression, protein binding, participation in signaling networks that influence cellular processes such as proliferative phenotype, migration, invasiveness, epithelial-mesenchymal transition (EMT), cycle regulation, drug resistance, and more. Furthermore, AFAP1-AS1 is implicated in guiding clinicopathological characteristics.

CONCLUSION

AFAP1-AS1 holds promise as a potent diagnostics and treatment option for gynecological and genitourinary systems in the future.

LncRNA CAI2 Contributes to Poor Prognosis of Glioma through the PI3K-Akt Signaling Pathway

AIMS

We aim to explore new potential therapeutic targets and markers in human glioma.

BACKGROUND

Gliomas are the most common malignant primary tumor in the brain.

OBJECTIVE

In the present research, we evaluated the effect of CAI2, a long non-coding RNA, on the biological behaviors of glioma and explored the related molecular mechanism.

METHODS

The expression of CAI2 was analyzed using qRT-PCR in 65 cases of glioma patients. The cell proliferation was determined with MTT and colony formation assays, and the PI3K-AKt signaling pathway was analyzed using western blot.

RESULTS

CAI2 was upregulated in human glioma tissue compared with the matched, adjacent nontumor tissue and was correlated with WHO grade. Survival analyses proved that the overall survival of patients with high CAI2 expression was poor compared to that of patients with low CAI2 expression. High CAI2 expression was an independent prognostic factor in glioma. The absorbance values in the MTT assay after 96 h were .712 ± .031 for the si-control and .465 ± .018 for the si- CAI2-transfected cells, and si-CAI2 inhibited colony formation in U251 cells by approximately 80%. The levels of PI3K, p-AKt, and AKt in si-CAI2-treated cells were decreased.

CONCLUSION

CAI2 may promote glioma growth through the PI3K-AKt signaling pathway. This research provided a novel potential diagnostic marker for human glioma.

Dissection of transcriptomic and epigenetic heterogeneity of grade 4 gliomas: implications for prognosis

BACKGROUND

Grade 4 glioma is the most aggressive and currently incurable brain tumor with a median survival of one year in adult patients. Elucidating novel transcriptomic and epigenetic contributors to the molecular heterogeneity underlying its aggressiveness may lead to improved clinical outcomes.

METHODS

To identify grade 4 glioma -associated 5-hydroxymethylcytosine (5hmC) and transcriptomic features as well as their cross-talks, genome-wide 5hmC and transcriptomic profiles of tissue samples from 61 patients with grade 4 gliomas and 9 normal controls were obtained for differential and co-regulation/co-modification analyses. Prognostic models on overall survival based on transcriptomic features and the 5hmC modifications summarized over genic regions (promoters, gene bodies) and brain-derived histone marks were developed using machine learning algorithms.

RESULTS

Despite global reduction, the majority of differential 5hmC features showed higher modification levels in grade 4 gliomas as compared to normal controls. In addition, the bi-directional correlations between 5hmC modifications over promoter regions or gene bodies and gene expression were greatly disturbed in grade 4 gliomas regardless of IDH1 mutation status. Phenotype-associated co-regulated 5hmC-5hmC modules and 5hmC-mRNA modules not only are enriched with different molecular pathways that are indicative of the pathogenesis of grade 4 gliomas, but also are of prognostic significance comparable to IDH1 mutation status. Lastly, the best-performing 5hmC model can predict patient survival at a much higher accuracy (c-index = 74%) when compared to conventional prognostic factor IDH1 (c-index = 57%), capturing the molecular characteristics of tumors that are independent of IDH1 mutation status and gene expression-based molecular subtypes.

CONCLUSIONS

The 5hmC-based prognostic model could offer a robust tool to predict survival in patients with grade 4 gliomas, potentially outperforming existing prognostic factors such as IDH1 mutations. The crosstalk between 5hmC and gene expression revealed another layer of complexity underlying the molecular heterogeneity in grade 4 gliomas, offering opportunities for identifying novel therapeutic targets.

Hub gene target of glioblastoma: LOX, SERPINH1 and TGFBI

Glioblastoma (GBM) is a malignant tumor. The long-term prognosis of the patients is poor. Therefore, it is of important clinical value to further explore the pathogenesis and look for molecular markers for early diagnosis and targeted treatment. Two expression profiling datasets [GSE50161 (GPL570 platform), GSE116520 (GPL10558 platform)] were respectively downloaded from the gene expression omnibus database. Volcano diagrams show the Differently expressed genes (DEGs) of GSE50161 and GSE116520. A Venn diagram revealed 467 common DEGs between the 2 datasets. Lysyl oxidase (LOX), serpin family H member 1 (SERPINH1) and transforming growth factor beta induced (TGFBI) were negatively correlated with the overall survival rate in patients with GBM. The hub genes are high in GBM tumor tissues. The relative expression levels of LOX, SERPINH1 and TGFBI were significantly higher in GBM samples, compared with the normal brain tissues groups. Bioinformatics technology could be a useful tool to predict progression of GBM and to explore the mechanism of GBM.LOX, SERPINH1 and TGFBI may be involved in the mechanism of the occurrence and development of GBM, and may be used as molecular targets for early diagnosis and specific treatment. DEGs identified using GEO2R. Functional annotation of DEGs using Kyoto Encyclopedia of Genes and Genomes and gene body pathway enrichment analysis. Construction of a protein-protein interaction network. The pathway and process enrichment analysis of the hub genes were performed by Metascape. Survival analysis was performed in gene expression profiling interactive analysis. Real-time fluorescent quantitative polymerase chain reaction assay was performed to verify. The animal model was established for western blot test analysis.

Long non-coding RNA LINC01018 inhibits human glioma cell proliferation and metastasis by directly targeting miRNA-182-5p

AIM

Accumulating evidence suggests that lncRNAs are potential biomarkers and key regulators of tumor development and progression. However, the precise function of most lncRNAs in glioma remains unknown. In this study, we explored the role of long intergenic non-protein coding RNA 1018 (LINC01018) in human glioma.

METHODS

Expression levels of LINC01018 and miR-182-5p in clinical glioma tissues and cell lines were detected by quantitative real-time PCR (qRT-PCR). Cell proliferation, migration, and invasion were determined by Cell Counting Kit-8 (CCK-8) assay and Transwell assay. Epithelial-mesenchymal transition (EMT) related proteins were measured by Western blotting. Direct relationship between LINC01018 and miR-182-5p was tested by dual-luciferase reporter assay, RNA immunoprecipitation assay (RIP), and rescue assays. Lastly, bioinformatics analyses were conducted to predict the downstream factors of LINC01018/miR-182-5p axis in glioma.

RESULTS

LINC01018 was significantly down-regulated in glioma tissues and cell lines. Overexpression of LINC01018 dramatically inhibited cell proliferation, migration, and invasion and reverse EMT process in glioma. LINC01018 directly target to miR-182-5p. Forced up-regulation of miR-182-5p reversed the inhibitory effects on proliferative and metastatic abilities of glioma cells with LINC01018 overexpression. Lastly, the bioinformatics analyses revealed that LINC01018/miR-182-5p axis mediated a cluster of downstream genes (ADRA2C, RAB6B, RAB27B, RAPGEF5, STEAP2, TAGLN3, and UNC13C), which were potential key factors in the development of glioma.

CONCLUSION

LINC01018 inhibits cell proliferation and metastasis in human glioma by targeting miR-182-5p, and should be considered as a potential therapeutic target in this cancer.

Regulation of temozolomide resistance via lncRNAs: Clinical and biological properties of lncRNAs in gliomas (Review)

Gliomas are a primary types of intracranial malignancies and are characterized by a poor prognosis due to aggressive recurrence profiles. Temozolomide (TMZ) is an auxiliary alkylating agent that is extensively used in conjunction with surgical resection and forms the mainstay of clinical treatment strategies for gliomas. However, the frequent occurrence of TMZ resistance in clinical practice limits its therapeutic efficacy. Accumulating evidence has demonstrated that long non‑coding RNAs (lncRNAs) can play key and varied roles in glioma progression. lncRNAs have been reported to inhibit glioma progression by targeting various signaling pathways. In addition, the differential expression of lncRNAs has also been found to mediate the resistance of glioma to several chemotherapeutic agents, particularly to TMZ. The present review article therefore summarizes the findings of previous studies in an aim to report the significance and function of lncRNAs in regulating the chemoresistance of gliomas. The present review may provide further insight into the clinical treatment of gliomas.

Comprehensive analyses indicated the association between m6A related long non-coding RNAs and various pathways in glioma

BACKGROUND

Glioma is one of the most malignant brain tumors and diseases. N6-methyladenosine modification (m6A) is the most abundant and prevalent internal chemical modification of mRNA and long non-coding RNAs (lncRNAs) in eukaryotes. Nevertheless, the correlated pathways and clinical utilization of m6A-related lncRNAs have not been fully evaluated in glioma.

METHODS

Public RNA-sequencing and clinical annotation data were retrieved from TCGA, CGGA and GEO database. Differential expression analysis and univariate Cox regression analysis were performed to identify the m6A-related and differentially expressed lncRNAs with prognostic function (m6A-DELPF). The consensus clustering was performed to identify the expression pattern of m6A-DELPF. LASSO Cox regression analysis was performed to construct the lncRNA-based signature. The CIBERSORT and ESTIMATE algorithms were performed to analyze immune infiltration and tumor microenvironment, respectively. Immunotherapy sensitivity analysis was performed using data from TCIA. The small molecule drugs prediction analysis was performed using The Connectivity Map (CMap) database and STITCH database. A competing endogenous RNAs (ceRNA) network was constructed based on miRcode, miRDB, miRTarBase, TargetScan database.

RESULTS

Two clusters (cluster1 and cluster2) were identified after unsupervised cluster analysis based on m6A-DELPF. Additionally, a 15-gene prognostic signature namely m6A-DELPFS was constructed. Analyses of epithelial-mesenchymal-transition score, tumor microenvironment, immune infiltration, clinical characterization analysis, and putative drug prediction were performed to confirm the clinical utility and efficacy of m6A-DELPFS. The potential mechanisms including tumor immune microenvironment of m6A-DELPF influence the initiation and progression of glioma. A clinically accessible nomogram was also constructed based on the m6A-DELPF and other survival-relevant clinical parameters. Two miRNAs and 114 mRNAs were identified as the downstream of seven m6A-related lncRNAs in a ceRNA network.

CONCLUSION

Our present research confirmed the clinical value of m6A related lncRNAs and their high correlation with tumor immunity, tumor microenvironment, tumor mutation burden and drug sensitivity in glioma.

Potential Biological Roles of Exosomal Long Non-Coding RNAs in Gastrointestinal Cancer

Exosomes, a type of extracellular vesicles (EVs), are secreted by almost all cells and contain many cellular constituents, such as nucleic acids, lipids, and metabolites. In addition, they play a crucial role in intercellular communication and have been proved to be involved in the development and treatment of gastrointestinal cancer. It has been confirmed that long non-coding RNAs (lncRNAs) exert a range of biological functions, such as cell metastasis, tumorigenesis, and therapeutic responses. This review mainly focused on the emerging roles and underlying molecular mechanisms of exosome-derived lncRNAs in gastrointestinal cancer in recent years. The biological roles of exosomal lncRNAs in the pathogenesis and therapeutic responses of gastrointestinal cancers were also investigated.

lncRNA PRADX is a Mesenchymal Glioblastoma Biomarker for Cellular Metabolism Targeted Therapy

Glioblastoma (GBM) is the most common and lethal type of primary malignant central nervous system (CNS) tumor with an extremely poor prognosis, and the mesenchymal subtype of GBM has the worst prognosis. Here, we found that lncRNA PRADX was overexpressed in the mesenchymal GBM and was transcriptionally regulated by RUNX1-CBFβ complex, overexpressed PRADX suppressed BLCAP expression via interacting with EZH2 and catalyzing trimethylation of lysine 27 on histone H3 (H3K27me3). Moreover, we showed that BLCAP interacted with STAT3 and reduced STAT3 phosphorylation, overexpressed PRADX activated STAT3 phosphorylation, and promoted ACSL1 expression via suppressing BLCAP expression, accelerating tumor metabolism. Finally, we determined that combined of ACSL1 and CPT1 inhibitors could reverse the accelerated cellular metabolism and tumor growth induced by PRADX overexpression in vivo and in vitro. Collectively, PRADX/PRC2 complex activated the STAT3 pathway and energy metabolism in relation to mesenchymal GBM progression. Furthermore, our findings provided a novel therapeutic strategy targeting the energy metabolism activity of GBM.

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.

A positive feedback loop of lncRNA-RMRP/ZNRF3 axis and Wnt/β-catenin signaling regulates the progression and temozolomide resistance in glioma

Drug resistance strikingly limits the therapeutic effect of temozolomide (TMZ) (a common drug for glioma). Long non-coding RNA (lncRNA) RMRP has been found to be implicated in glioma progression. However, the effect of RMRP on TMZ resistance along with related molecular mechanisms is poorly defined in glioma. In the present study, RMRP, ZNRF3, and IGF2BP3 were screened out by bioinformatics analysis. The expression levels of lncRNAs and mRNAs were measured by RT-qPCR assay. Protein levels of genes were detected by western blot and immunofluorescence assays. ZNRF3 mRNA stability was analyzed using Actinomycin D assay. Cell proliferative ability and survival rate were determined by CCK-8 assay. Cell apoptotic pattern was estimated by flow cytometry. The effect of RMRP knockdown on the growth of TMZ-treated glioma xenograft tumors was explored in vivo. The relationships of IGF2BP3, RMRP, and ZNRF3 were explored by bioinformatics prediction analysis, RNA immunoprecipitation, luciferase, and RNA pull-down, and chromatin immunoprecipitation assays. The results showed that RMRP was highly expressed in glioma. RMRP knockdown curbed cell proliferation, facilitated cell apoptosis and reduced TMZ resistance in glioma cells, and hindered the growth of TMZ-treated glioma xenograft tumors. RMRP exerted its functions by down-regulating ZNRF3 in glioma cells. IGF2BP3 interacted with RMRP and ZNRF3 mRNA. IGF2BP3 knockdown weakened the interaction of Argonaute 2 (Ago2) and ZNRF3. RMRP reduced ZNRF3 expression and mRNA stability by IGF2BP3. RMRP knockdown inhibited β-catenin expression by up-regulating ZNRF3. The inhibition of Wnt/β-catenin signaling pathway by XAV-939 weakened RMRP-mediated TMZ resistance in glioma cells. β-catenin promoted RMRP expression by TCF4 in glioma cells. In conclusion, RMRP/ZNRF3 axis and Wnt/β-catenin signaling formed a positive feedback loop to regulate TMZ resistance in glioma. The sustained activation of Wnt/β-catenin signaling by RMRP might contribute to the better management of cancers.

LncRNA RP1-86C11.7 exacerbates the glioma progression and oncogenicity by hsa-miR-144-3p/TFRC signaling

•

High level of TFRC promotes the glioma development.

•

Hsa-miR-144-3p inhibitor glioma growth by targeting TFRC.

•

LncRNA RP1-86C11.7 exacerbates glioma progression through sponging to hsa-miR-144-3p, resulting in TFRC upregulation.

Glioblastoma (GBM) remains the most common and malignant tumor of the human central nervous system. Increasing evidence has highlighted that tumor cells with high transferrin receptor (TFRC) expression show advantages in growth. Long noncoding RNAs (lncRNAs) are related to glioma progression by mediating microRNAs (miRNAs). However, the underlying mechanism among TFRC, miRNA and lncRNA in GBM is limited. In the current study, we identified a new lncRNA-induced signaling mechanism that regulates the TFRC levels in GBM. The TFRC level was higher in glioma cell lines, and elevated TFRC expression promoted the proliferation and survival of glioma cells. Further study showed that hsa-miR-144a-3p bound to the 3′-UTR of TFRC mRNA and inhibited its expression, preventing the malignant properties of glioma cells, such as proliferation and survival. We also found that the lncRNA RP1-86C11.7 sponges hsa-miR-144-3p to suppress its protective role in glioma. RP1-86C11.7 overexpression in glioma cells elevated TFRC expression, increased the intracellular free iron level, and deteriorated oncogenicity, with a significant reduction in hsa-miR-144-3p. By contrast, silencing RP1-86C11.7 upregulated the hsa-miR-144-3p level, resulting in decreased TFRC expression and repressed glioma progression. However, the effect of silencing RP1-86C11.7 was reversed with simultaneous hsa-miR-144-3p inhibitor treatment: the TFRC level, intracellular iron level and proliferation in glioma cells increased. Mechanistically, our data indicated that RP1-86C11.7 exacerbates the malignant behavior of glioma through the hsa-miR-144-3p/TFRC axis. RP1-86C11.7 may be a potential biomarker or target to treat glioma in the future.

Comprehensive Analysis of YTH Domain Family in Lung Adenocarcinoma: Expression Profile, Association with Prognostic Value, and Immune Infiltration

Background

All YTH domain family members are m⁶A reader proteins accounting for the methylation modulation involved in the process of tumorgenesis and tumor progression. However, the expression profiles and roles of the YTH domain family in lung adenocarcinoma (LUAD) remain to be further illustrated.

Methods

GEPIA2 and TNMplot databases were used to generate the expression profiles of the YTH family. Kaplan-Meier plotter database was employed to analysis the prognostic value of the YTH family. Coexpression profiles and genetic alterations analysis of the YTH family were undertaken using the cBioPortal database. YTH family protein-associated protein-protein interaction (PPI) network was identified by using STRING. Functional enrichment analysis was performed with the help of the WebGestalt database. The correlation analysis between the YTH family and immune cell infiltration in LUAD was administrated by using the TIMER2.0 database.

Results

mRNA expression of YTHDC1 and YTHDC2 was significantly lower in LUAD, whereas YTHDF1, YTHDF2, and YTHDF3 with apparently higher expression. YTHDF2 expression was observed to be the highest in the nonsmoker subgroup, and its expression gradually decreased with the increased severity of smoking habit. LUAD patients with low expression of YTHDC2, YTHDF1, and YTHDF2 were correlated with a better overall survival (OS) time. The YTHDF1 genetic alteration rate was 26%, which was the highest in the YTH family. The major cancer-associated functions of YTH family pointed in the direction of immunomodulation, especially antigen processing and presentation. Most of the YTH family members were significantly correlated with the infiltration of CD4+ T cells, CD8+ T cells, macrophages, and neutrophils, indicating the deep involvement of the YTH domain family in the immune cell infiltration in LUAD.

Conclusion

The molecular and expression profiles of the YTH family were dysregulated in LUAD. YTH family members (especially YTHDC2) were promising biomarkers and potential therapeutic targets that may bring benefit for the patients with LUAD.

Genome-wide profiling of alternative splicing in glioblastoma and their clinical value

Background

Alternative splicing (AS), one of the main post-transcriptional biological regulation mechanisms, plays a key role in the progression of glioblastoma (GBM). Systematic AS profiling in GBM is limited and urgently needed.

Methods

TCGA SpliceSeq data and the corresponding clinical data were downloaded from the TCGA data portal. Survival-related AS events were identified through Kaplan–Meier survival analysis and univariate Cox analysis. Then, splicing correlation network was constructed based on these AS events and associated splicing factors. LASSO regression followed by multivariate Cox analysis was performed to validate independent AS biomarkers and to construct a risk prediction model. Enrichment analysis was subsequently conducted to explore potential signaling pathways of these AS events.

Results

A total of 132 TCGA GBM samples and 45,610 AS events were included in our study, among which 416 survival-related AS events were identified. An AS correlation network, including 54 AS events and 94 splicing factors, was constructed, and further functional enrichment was performed. Moreover, the novel risk prediction model we constructed displayed moderate performance (the area under the curves were > 0.7) at both one, two and three years.

Conclusions

Survival-related AS events may be vital factors of both biological function and prognosis. Our findings in this study can deepen the understanding of the complicated mechanisms of AS in GBM and provide novel insights for further study. Moreover, our risk prediction model is ready for preliminary clinical applications. Further verification is required.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08681-z.

Long Non-coding RNA: An Emerging Contributor and Potential Therapeutic Target in Renal Fibrosis

Renal fibrosis (RF) is a pathological process that culminates in terminal renal failure in chronic kidney disease (CKD). Fibrosis contributes to progressive and irreversible decline in renal function. However, the molecular mechanisms involved in RF are complex and remain poorly understood. Long non-coding RNAs (lncRNAs) are a major type of non-coding RNAs, which significantly affect various disease processes, cellular homeostasis, and development through multiple mechanisms. Recent investigations have implicated aberrantly expressed lncRNA in RF development and progression, suggesting that lncRNAs play a crucial role in determining the clinical manifestation of RF. In this review, we comprehensively evaluated the recently published articles on lncRNAs in RF, discussed the potential application of lncRNAs as diagnostic and/or prognostic biomarkers, proposed therapeutic targets for treating RF-associated diseases and subsequent CKD transition, and highlight future research directions in the context of the role of lncRNAs in the development and treatment of RF.

A positive feedback loop of LINC00662 and STAT3 promotes malignant phenotype of glioma

BACKGROUND

Long noncoding RNAs (lncRNAs) have been reported to be associated with tumorigenesis and development of glioma. LINC00662 has been involved in the pathogenesis of various human cancers. However, the mechanism underlying which LINC00662 exerts its role in glioma needs further exploration. In addition, regulation mechanism of LINC00662 expression in glioma remains unknown.

METHODS AND MATERIALS

RT-qPCR was performed to evaluate the expression levels of LINC00662, miR-340-5p in glioma tissues and cell lines. The effect of LINC00662 and miR-340-5p in cell proliferation and invasion was assessed by Cell Counting Kit-8(CCK-8), clone colony formation and Transwell assay. Luciferase reporter assays and RNA immunoprecipitation assay validated the miR-340-5p-target relationships with LINC00662 or STAT3. CHIP-qPCR and Luciferase reporter assays were used to demonstrate the interaction between STAT3 and the promoter region of LINC00662. A tumor xenografts model was implemented to verify the effect of LINC00662 on glioma development in vivo.

RESULTS

We found that LINC00662 was frequently highly expressed and related to the malignant phenotype of glioma. LINC00662 knockdown inhibited the proliferation, invasion and glioma genesis of glioma. LINC00662 acted as a ceRNA sponging miR-340-5p to protect the expression of STAT3. In addition, STAT3 was forced to the promoter region of LINC00662 and promoted its transcription. In vivo experiments demonstrated that targeting LINC00662 may be a potential strategy in glioma therapy.

CONCLUSION

There was a positive regulation loop between LINC00662 and STAT3 in glioma. LINC00662 might be an oncogene in glioma. Targeting LINC00662 was a potential strategy in glioma therapy.

Expression and regulatory roles of lncRNAs in G-CIMP-low vs G-CIMP-high Glioma: an in-silico analysis

BACKGROUND

Clinically relevant glioma subtypes, such as the glioma-CpG island methylator phenotype (G-CIMP), have been defined by epigenetics. In this study, the role of long non-coding RNAs in association with the poor-prognosis G-CMIP-low phenotype and the good-prognosis G-CMIP-high phenotype was investigated. Functional associations of lncRNAs with mRNAs and miRNAs were examined to hypothesize influencing factors of the aggressive phenotype.

METHODS

RNA-seq data on 250 samples from TCGA's Pan-Glioma study, quantified for lncRNA and mRNAs (GENCODE v28), were analyzed for differential expression between G-CIMP-low and G-CIMP-high phenotypes. Functional interpretation of the differential lncRNAs was performed by Ingenuity Pathway Analysis. Spearman rank order correlation estimates between lncRNA, miRNA, and mRNA nominated differential lncRNA with a likely miRNA sponge function.

RESULTS

We identified 4371 differentially expressed features (mRNA = 3705; lncRNA = 666; FDR ≤ 5%). From these, the protein-coding gene TP53 was identified as an upstream regulator of differential lncRNAs PANDAR and PVT1 (p = 0.0237) and enrichment was detected in the "development of carcinoma" (p = 0.0176). Two lncRNAs (HCG11, PART1) were positively correlated with 342 mRNAs, and their correlation estimates diminish after adjusting for either of the target miRNAs: hsa-miR-490-3p, hsa-miR-129-5p. This suggests a likely sponge function for HCG11 and PART1.

CONCLUSIONS

These findings identify differential lncRNAs with oncogenic features that are associated with G-CIMP phenotypes. Further investigation with controlled experiments is needed to confirm the molecular relationships.

Long non-coding RNAs in brain tumors

Long non-coding RNAs (lncRNAs) have been found to be central players in the epigenetic, transcriptional and post-transcriptional regulation of gene expression. There is an accumulation of evidence on newly discovered lncRNAs, their molecular interactions and their roles in the development and progression of human brain tumors. LncRNAs can have either tumor suppressive or oncogenic functions in different brain cancers, making them attractive therapeutic targets and biomarkers for personalized therapy and precision diagnostics. Here, we summarize the current state of knowledge of the lncRNAs that have been implicated in brain cancer pathogenesis, particularly in gliomas and medulloblastomas. We discuss their epigenetic regulation as well as the prospects of using lncRNAs as diagnostic biomarkers and therapeutic targets in patients with brain tumors.

LncRNA RP11-84E24.3 drives tumorigenesis and epithelial-to-mesenchymal transition of glioma cells by promoting TFAP2C-mediated activation of SNAI1

PURPOSE

Long noncoding RNAs (LncRNAs) are essential epigenetic regulators with critical roles in tumor initiation and malignant progression; however, the mechanism by which aberrantly expressed lncRNA RP11-84E24.3 regulates the pathogenesis of glioma is not fully understood. Here, we investigate the function of lncRNA RP11-84E24.3 in glioma onset and progression as well as identify a molecular pathway regulated by this lncRNA.

METHODS

Differentially expressed lncRNAs related to glioma were identified. The aberrant expression of lncRNA RP11-84E24.3 was verified in samples from patients with glioma as well as glioma cell lines. The role of lncRNA RP11-8424.3 in proliferation, apoptosis, migration, and invasion was assessed using gain- and loss-of function approaches, EdU incorporation, flow cytometry, wound healing and Transwell invasion assays. Western blot analysis was utilized to examine the expression of proteins associated with epithelial-to-mesenchymal transition (EMT). The interaction between lncRNA RP11-84E24.3, TFAP2C and SNAI1 was confirmed using RNA pull-down, ChIP and luciferase reporter assays.

RESULTS

LncRNA RP11-84E24.3 was up-regulated in both glioma tissues and cell lines. LncRNA RP11-84E24.3 overexpression enhanced the proliferation, migration and invasion of glioma cells while reducing apoptosis. This was associated with a decrease in E-cadherin expression and an increase in N-cadherin and Vimentin expression. LncRNA RP11-84E24.3 directly targeted TFAP2C protein, resulting in increased SNAI1 expression. Knockdown of TFAP2C or SNAI1 reversed the effects of lncRNA RP11-84E24.3 overexpression, while silencing lncRNA RP11-84E24.3 inhibited tumor formation of glioma cells in vivo.

CONCLUSIONS

LncRNA RP11-84E24.3 increased SNAI1 expression by forming a complex with TFAP2C protein, promoting EMT in glioma cells and tumor formation.

Dysregulation of lnc-SNHG1 and miR-216b-5p correlate with chemoresistance and indicate poor prognosis of serous epithelial ovarian cancer

Aim

This study aimed to explore whether the dysregulation of lnc-small nucleolar RNA host gene 1 (SNHG1) and miR-216b-5p correlated with chemoresistance and indicated poor prognosis of serous epithelial ovarian cancer (EOC).

Methods and results

The expression of lnc-SNHG1 was upregulated, while miR-216b-5p showed low expression in patients with chemoresistant EOC compared with patients with chemosensitive EOC. The multivariate Cox regression analysis showed that the expression of miR-216b-5p and FIGO stage were independent prognostic factors for the overall survival (OS) of patients with serous EOC. Kaplan–Meier curves revealed a significant association of the increased expression level of lnc-SNHG1 with shorter OS and disease-free survival (DFS). Patients with a low expression level of miR-216b-5p also had shorter OS and DFS. The biological functions were tested using CCK-8 assay, colony formation assay, wound healing assay, and cell apoptosis. The knockdown of SNHG1 and the overexpression of miR-216b-5p stimulated paclitaxel sensitivity in A2780/Taxol cells through inhibiting cell growth and migration and promoting apoptosis. The inhibition of miR-216b-5p could rescue the effect of lnc-SNHG1 inhibition on the sensitivity of A2780/Taxol cells to paclitaxel. Luciferase reporter assay, RNA Binding Protein Immunoprecipitation Assay (RIP), and quantitative reverse transcription–polymerase chain reaction (qRT-PCR) indicated that lnc-SNHG1 acted as a sponge of miR-216b-5p in A2780/Taxol cells.

Conclusions

This study showed that the overexpression of lnc-SNHG1 and decreased expression level of miR-216b-5p correlated with the chemoresistance of patients with serous EOC and indicated shorter OS and DFS. Lnc-SNHG1 functioned as a ceRNA with miR-216b-5p, which was critical in modulating the paclitaxel sensitivity of ovarian cancer cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-020-00750-4.

lnc-HOTAIR predicts hepatocellular carcinoma in chronic hepatitis C genotype 4 following direct-acting antivirals therapy

Emerging hepatocellular carcinoma (HCC) has been sequentially reported in chronic hepatitis C virus (HCV) treated with direct-acting antivirals (DAAs). Homeobox transcript antisense RNA (HOTAIR), an oncogene, has been reported to be associated with cancer. We investigated the predictive value of lnc-HOTAIR for HCC surveillance in chronic HCV patients following DAAs therapy. The expression levels of lnc-HOTAIR and ATG-7 genes were measured in 220 with chronic HCV, following a DAAs based therapy for 12 weeks, the patients were followed-up for attentive surveillance of HCC for 12 months after starting DAAs. In terms of lnc-HOTAIR, patients with HCC and high viral load had significantly higher median expression levels of HOTAIR of (68 vs. 24; p = .001) and (94 vs. 52; p = .001), respectively. Moreover, the median expression level of ATG-7 was higher in those who developed HCC (114 vs. 51; p = .001). The expression of lnc-HOTAIR and ATG-7 are significant predictors of the development of HCC in HCV-4 infected patients treated with DAAs, with a cut-off value of 37 and 86, respectively. The increased expression levels of lnc-HOTAIR more than 68 in HCC patients following DAAs were correlated with poorer disease outcomes compared to those with lower expression levels; however, ATG-7 expression levels more than 114 were correlated with worse overall survival but not the progression-free one. We suggest that high expression levels of lnc-HOTAIR could serve as a risk assessment biomarker for HCC before and during DAAs course therapy in Chronic HCV-4 patients, and should be rigorously taken into consideration before DAAs.

ncDRMarker: a computational method for identifying non-coding RNA signatures of drug resistance based on heterogeneous network

Background

Drug resistance is the primary cause of failure in the treatment of cancer. Identifying signatures of chemoresistance will help to overcome this problem. Current drug resistance studies focus on protein-coding genes and ignore non-coding RNAs (ncRNAs), rendering it a challenging task to systematically identify ncRNAs involved in drug resistance.

Methods

In this study, protein-protein, miRNA-target gene, miRNA-lncRNA interactions were integrated to construct a mRNA-miRNA-lncRNA network. Then, the random walk with restart (RWR) method was extended to the network for identifying ncRNA signatures of drug resistance. The leave-one-out cross validation (LOOCV) and receiver operating characteristic curve (ROC) were used to estimate the performance of ncDRMarker. Wilcoxon rank-sum test was used to validate the identified ncRNAs in NCI-60 cancer cell lines. KEGG pathway enrichment analysis was implemented to characterize the biological function of some identified ncRNAs.

Results

We performed this method on ten common clinical chemotherapy drugs and analyzed the results in detail. The region beneath the ROC was up to 0.881–0.951, which did not change significantly in the incomplete network, indicating the high performance and robustness of the method. Further, we confirmed the role of the identified ncRNAs in drug resistance, i.e., miR-92a-3p, a candidate chemoresistance ncRNA of tamoxifen and paclitaxel, can significantly classify cancer cell lines into sensitive or resistant to tamoxifen (or paclitaxel). We also dissected the mRNA-miRNA-lncRNA composite network and found that some hub ncRNAs, such as miR-124-3p, were involved in resistance of multiple drugs and engaged in many significant cancer-related pathways. Lastly, we have provided a ncDRMarker platform for users to identify candidate ncRNAs of drug resistance, which is available at http://bio-bigdata.hrbmu.edu.cn/ncDRMarker/index.

Conclusions

Our findings suggest that ncDRMarker is an effective computational technique for prioritizing candidate ncRNAs of drug resistance. Additionally, the identified ncRNAs could be targeted to overcome drug resistance and help realize individualized treatment.

LncRNA SNHG16 Promotes Proliferation, Migration, and Invasion of Glioma Cells Through Regulating the miR-490/PCBP2 Axis

Background: Glioma is the most common tumor of the central nervous system, which has a high mortality and recurrence rate. Increasing evidence shows that long noncoding RNAs (lncRNA) are closely related to the occurrence of cancer. However, the mechanism of lncRNA small nucleolar RNA host gene 16 (SNHG16) in glioma remains to be studied. Materials and Methods: The expression levels of SNHG16, microRNA-490 (miR-490), and poly(C)-binding proteins 2 (PCBP2) in tissues and cells were determined by quantitative real-time polymerase chain reaction. 3-(4, 5-dimethyl-2 thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) and transwell assays were used to evaluate the proliferation, migration, and invasion abilities of glioma cells. Moreover, Western blot analysis was performed to assess the levels of PCBP2 and proliferation-related and metastasis-related proteins. Dual-luciferase reporter assay was used to verify the interaction among SNHG16, miR-490, and PCBP2. Results: SNHG16 was highly expressed in glioma tissues and cells, and silenced-SNHG16 suppressed the proliferation, migration, and invasion of glioma cells. Besides, SNHG16 could interact with miR-490. The aberrant expression of SNHG16 restored the inhibitory effect of miR-490 overexpression on the proliferation, migration, and invasion of glioma cells. Moreover, PCBP2 was a target of miR-490. MiR-490 inhibitor recovered the suppression effect of PCBP2 knockdown on glioma progression, and PCBP2 overexpression also could reverse the inhibition effect of miR-490 mimic on glioma progression. In addition, SNHG16 promoted the expression of PCBP2, while miR-490 inhibited its expression. Conclusions: The authors' data revealed that SNHG16 might function as an oncogene in glioma through regulating the miR-490/PCBP2 axis, and the elucidating of the mechanism of SNHG16 provided a potential therapeutic target for glioma.

Coding of Glioblastoma Progression and Therapy Resistance through Long Noncoding RNAs

Glioblastoma is the most aggressive and lethal primary brain malignancy, with an average patient survival from diagnosis of 14 months. Glioblastoma also usually progresses as a more invasive phenotype after initial treatment. A major step forward in our understanding of the nature of glioblastoma was achieved with large-scale expression analysis. However, due to genomic complexity and heterogeneity, transcriptomics alone is not enough to define the glioblastoma “fingerprint”, so epigenetic mechanisms are being examined, including the noncoding genome. On the basis of their tissue specificity, long noncoding RNAs (lncRNAs) are being explored as new diagnostic and therapeutic targets. In addition, growing evidence indicates that lncRNAs have various roles in resistance to glioblastoma therapies (e.g., MALAT1, H19) and in glioblastoma progression (e.g., CRNDE, HOTAIRM1, ASLNC22381, ASLNC20819). Investigations have also focused on the prognostic value of lncRNAs, as well as the definition of the molecular signatures of glioma, to provide more precise tumor classification. This review discusses the potential that lncRNAs hold for the development of novel diagnostic and, hopefully, therapeutic targets that can contribute to prolonged survival and improved quality of life for patients with glioblastoma.

Mir-370-3p Impairs Glioblastoma Stem-Like Cell Malignancy Regulating a Complex Interplay between HMGA2/HIF1A and the Oncogenic Long Non-Coding RNA (lncRNA) NEAT1

Glioblastoma (GBM) is the most aggressive and prevalent form of a human brain tumor in adults. Several data have demonstrated the implication of microRNAs (miRNAs) in tumorigenicity of GBM stem-like cells (GSCs). The regulatory functions of miRNAs in GSCs have emerged as potential therapeutic candidates for glioma treatment. The current study aimed at investigating the function of miR-370-3p in glioma progression, as aberrant expression of miR-370-3p, is involved in various human cancers, including glioma. Analyzing our collection of GBM samples and patient-derived GSC lines, we found the expression of miR-370-3p significantly downregulated compared to normal brain tissues and normal neural stem cells. Restoration of miR-370-3p expression in GSCs significantly decreased proliferation, migration, and clonogenic abilities of GSCs, in vitro, and tumor growth in vivo. Gene expression analysis performed on miR-370-3p transduced GSCs, identified several transcripts involved in Epithelial to Mesenchymal Transition (EMT), and Hypoxia signaling pathways. Among the genes downregulated by the restored expression of miR-370-3p, we found the EMT-inducer high-mobility group AT-hook 2 (HMGA2), the master transcriptional regulator of the adaptive response to hypoxia, Hypoxia-inducible factor (HIF)1A, and the long non-coding RNAs (lncRNAs) Nuclear Enriched Abundant Transcript (NEAT)1. NEAT1 acts as an oncogene in a series of human cancers including gliomas, where it is regulated by the Epidermal Growth Factor Receptor (EGFR) pathways, and contributes to tumor growth and invasion. Noteworthy, the expression levels of miR-370-3p and NEAT1 were inversely related in both GBM tumor specimens and GSCs, and a dual-luciferase reporter assay proved the direct binding between miR-370-3p and the lncRNAs NEAT1. Our results identify a critical role of miR-370-3p in the regulation of GBM development, indicating that miR-370-3p acts as a tumor-suppressor factor inhibiting glioma cell growth, migration and invasion by targeting the lncRNAs NEAT1, HMGA2, and HIF1A, thus, providing a potential candidate for GBM patient treatment.

Long noncoding RNA DANCR knockdown inhibits proliferation, migration and invasion of glioma by regulating miR-135a-5p/BMI1

Background

Glioma is the most common and aggressive primary brain tumor with high mortality rate around the world. LncRNAs have been identified to play key roles in tumorigenesis in various cancers, including glioma. However, the precise mechanism of DANCR in progression of glioma remains poorly defined.

Methods

The expression levels of DANCR, miR-135a-5p and BMI1 were measured by qRT-PCR in glioma tissues and cells. Cell proliferation, migration and invasion were detected by CCK-8 assay and transwell assay, respectively. The possible binding sites of miR-135a-5p and DANCR or BMI1 were predicted by online software and verified using luciferase report assay and RNA immunoprecipitation (RIP) assay. Western blot analysis was carried out to detect the protein of BMI1 expression. A xenograft tumor model was established to investigate the functions of DANCR in glioma progression in vivo.

Results

DANCR was upregulated and miR-135a-5p was downregulated in glioma tissues and cells. Knockdown of DANCR inhibited cell proliferation, migration and invasion in glioma cells. In addition, miR-135a-5p was a direct target of DANCR, and its elevated expression could reverse miR-135a-5p inhibition-mediated progression of glioma. Moreover, miR-135a-5p could specially bind to BMI1, and the expression of BMI1 was obviously elevated in glioma tissues and cells. Furthermore, DANCR acted as a ceRNA to regulate BMI1 expression and BMI1-mediated effects on progression of glioma by sponging miR-135a-5p. Besides, inhibition of DANCR limited tumor growth by regulating miR-135a-5p and BMI1 expression in vivo.

Conclusion

DANCR knockdown inhibited cell proliferation, migration and invasion in glioma cells through regulating miR-135a-5p/BMI1 axis, providing viable therapeutic avenues for treatment of glioma.

Identification of a long non-coding RNA signature for predicting prognosis and biomarkers in lung adenocarcinoma

Long non-coding RNAs (lncRNAs) have a number of functions in various cellular processes and are potential prognostic factors for lung adenocarcinoma (LUAD). A gene risk model could provide novel evidence to improve the prediction of overall outcomes and provide more potential biomarkers. The present study aimed improve a previously published method of gene signature construction to make it more robust and accurate. The lncRNA expression profiles from 594 patients with LUAD were obtained from The Cancer Genome Atlas (TCGA) database and samples were divided into high- and low-risk groups based on median risk scores calculated using a prognosis-related risk score formula. Univariate Cox regression, least absolute shrinkage and selection operator algorithm and multivariate Cox regression were performed to construct a gene signature based on the differentially expressed lncRNAs in patients with LUAD. The robustness and accuracy of the present model was assessed using area under the calculated curves (AUC) and Kaplan-Meier (K-M) survival analysis of the high- and low-risk cohorts. Potential biomarkers associated with survival status were then identified using K-M survival analysis and potential biomarker functions were predicted using enrichment analysis of co-expressed mRNAs. The gene signature constructed contained 44 lncRNAs. The AUCs for 3- and 5-year survival with the model were 0.836 and 0.818, respectively, of a time-dependent receiver operator characteristic curve. Moreover, lncRNAs AC124804.1 and MIR34AHG were identified using K-M survival analysis and the potential function of these two lncRNAs was predicted using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional enrichment. The present lncRNA model provides novel insight which may improve prediction of prognosis for patients with LUAD and identify potentially novel biomarkers for the diagnosis.

Downregulation of SNRPG induces cell cycle arrest and sensitizes human glioblastoma cells to temozolomide by targeting Myc through a p53-dependent signaling pathway

Objective: Temozolomide (TMZ) is commonly used for glioblastoma multiforme (GBM) chemotherapy. However, drug resistance limits its therapeutic effect in GBM treatment. RNA-binding proteins (RBPs) have vital roles in posttranscriptional events. While disturbance of RBP-RNA network activity is potentially associated with cancer development, the precise mechanisms are not fully known. The SNRPG gene, encoding small nuclear ribonucleoprotein polypeptide G, was recently found to be related to cancer incidence, but its exact function has yet to be elucidated. Methods:SNRPG knockdown was achieved via short hairpin RNAs. Gene expression profiling and Western blot analyses were used to identify potential glioma cell growth signaling pathways affected by SNRPG. Xenograft tumors were examined to determine the carcinogenic effects of SNRPG on glioma tissues. Results: The SNRPG-mediated inhibitory effect on glioma cells might be due to the targeted prevention of Myc and p53. In addition, the effects of SNRPG loss on p53 levels and cell cycle progression were found to be Myc-dependent. Furthermore, SNRPG was increased in TMZ-resistant GBM cells, and downregulation of SNRPG potentially sensitized resistant cells to TMZ, suggesting that SNRPG deficiency decreases the chemoresistance of GBM cells to TMZ via the p53 signaling pathway. Our data confirmed that SNRPG suppression sensitizes GBM cells to TMZ by targeting Myc via the p53 signaling cascade. Conclusions: These results indicated that SNRPG is a probable molecular target of GBM and suggested that suppressing SNRPG in resistant GBM cells might be a substantially beneficial method for overcoming essential drug resistance.

Correlation between polymorphisms in IGF2/H19 gene locus and epithelial ovarian cancer risk in Chinese population

To investigate the association between SNPs in human IGF2/H19 gene locus and epithelial ovarian cancer (EOC) risk, we performed a case-control study in 422 individuals (219 EOC patients and 203 cancer-free controls). Four SNPs (rs2525885, rs2839698, rs3741206, rs3741219) were found to be related with EOC risk. Specifically, the minor allele C of rs2525885 and allele A of rs2839698 was associated with elevated EOC genetic susceptibility under both dominant and recessive models (TC + CC vs TT: adjusted OR: 1.61, P = .031; CC vs TT + TC: adjusted OR: 4.87, P = .014; GA + AA vs GG: adjusted OR: 1.63, P = .023; AA vs GG + GA: adjusted OR: 2.43, P = .007). For rs3741206, the genotype TC + CC was associated with a significant decrease in EOC risk with the TT genotype as reference in a dominant genetic model (adjusted OR: 0.44, P = .003), while for rs3741219, genotype AA was associated with a 59% decrease in EOC risk only in the recessive model (adjusted OR: 0.41, P = .038). In the stratified analysis, an increased risk associated with the variant genotypes was observed in only subjects aged >47 years for rs2525885 (adjusted OR = 2.04, P = .024), rs2839698 (adjusted OR = 2.50, P = .047) and rs3741206 (adjusted OR = 0.37, P = .009), respectively. What's more, the TC + CC genotype of rs2525885 was significantly associated with advanced FIGO stage (III vs II, adjusted OR = 2.73, P = .040).

Identification of Novel lncRNA Markers in Glioblastoma Multiforme and Their Clinical Significance: A Study Based on Multiple Sequencing Data

Background

Long non-coding RNAs (lncRNAs) have been verified to have a vital role in the progression of glioblastoma multiforme (GBM). Our research was about to identify the potential lncRNAs which was closely associated with the pathogenesis and prognosis of glioblastoma multiforme.

Methods

All RNA sequence profiling data from patients with GBM were obtained from The Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA). Differently expressed genes identified from GBM and control samples were used to construct competing endogenous RNA (ceRNA) network and perform corresponding functional enrichment analysis. Univariate Cox regression followed by lasso regression and multivariate Cox was used to validate independent lncRNA factors and construct a risk prediction model. Quantitative polymerase chain reaction (qPCR) was performed to verify the expression levels of potential lncRNA biomarkers in human GBM clinical specimens. A gene set enrichment analysis (GSEA) was subsequently conducted to explore potential signaling pathways in which critical lncRNAs may be involved. Moreover, nomogram plot was applied based on our prediction model and significant clinical covariates to visualize the prognosis of GBM patients.

Results

A total of 2023 differentially expressed genes (DEGs) including 56 lncRNAs, 1587 message RNAs (mRNAs) and 380 other RNAs were included. Based on predictive databases, 16lncRNAs, 32 microRNAs (miRNAs) and 99 mRNAs were used to construct a ceRNA network. Moreover, we performed a novel risk prediction model with 5 potential prognostic lncRNAs, in which 4 of them were newly identified in GBM, to predict the prognosis of GBM patients. Finally, a nomogram plot was constructed to illustrate the potential relationship between the prognosis of GBM and our risk prediction model and significant clinical covariates.

Conclusion

In this study, we identified 4 novel potential lncRNA biomarkers and constructed a prediction model of GBM prognosis. A simple-to-use nomogram was provided for further clinical application.

Long non-coding RNA PAXIP1-AS1 facilitates cell invasion and angiogenesis of glioma by recruiting transcription factor ETS1 to upregulate KIF14 expression

Background

Gliomas are common life-threatening cancers, mainly due to their aggressive nature and frequent invasiveness and long non-coding RNAs (lncRNAs) are emerging as promising molecular targets. Therefore, we explored the regulatory mechanisms underlying the putative involvement of the lncRNA PAX-interacting protein 1- antisense RNA1/ETS proto-oncogene 1/kinesin family member 14 (PAXIP1-AS1/ETS1/KIF14) axis in glioma cell invasion and angiogenesis.

Methods

Firstly, we identified differentially expressed lncRNA PAXIP1-AS1 as associated with glioma based on bioinformatic data. Then, validation experiments were conducted to confirm a high expression level of lncRNA PAXIP1-AS1 in glioma tissues and cells, accompanied by upregulated KIF14. We further examined the binding between lncRNA PAXIP1-AS1, KIF14 promoter activity, and transcription factor ETS1. Next, overexpression vectors and shRNAs were delivered to alter the expression of lncRNA PAXIP1-AS1, KIF14, and ETS1 to analyze their effects on glioma progression in vivo and in vitro.

Results

LncRNA PAXIP1-AS1 was mainly distributed in the nucleus of glioma cells. LncRNA PAXIP1-AS1 could upregulate the KIF14 promoter activity by recruiting transcription factor ETS1. Overexpression of lncRNA PAXIP1-AS1 enhanced migration, invasion, and angiogenesis of human umbilical vein endothelial cells in glioma by recruiting the transcription factor ETS1 to upregulate the expression of KIF14, which was further confirmed by accelerated tumor growth in nude mice.

Conclusions

The key findings of this study highlighted the potential of the lncRNA PAXIP1-AS1/ETS1/KIF14 axis as a therapeutic target for glioma treatment, due to its role in controlling the migration and invasion of glioma cells and its angiogenesis.

Targeting Long Non-Coding RNAs in Nervous System Cancers: New Insights in Prognosis, Diagnosis and Therapy

Long non-coding RNAs (lncRNAs) constitute one of the most broad and diverse classes of cellular transcripts, playing key roles as regulatory molecules in many biological processes. Although the biology of lncRNAs is a new and emerging field of research, several studies have already shown that alterations in the expression of lncRNAs are associated with the development and progression of cancer in different organs and tissues, including central and peripheral nervous system. In this review, we summarize the oncogenic and tumor suppressive roles of lncRNAs in malignant tumors of the nervous system, such as glioma and neuroblastoma, focusing on their functional interactions with DNA, other RNA and protein molecules. We further discuss the potential use of lncRNAs as biomarkers for diagnosis, prognosis and tumor treatment. Gaining insight into the functional association between nervous system malignancies and lncRNAs could offer new perspectives to the development of promising therapeutic tools against cancer.

Novel Function of lncRNA ADAMTS9-AS2 in Promoting Temozolomide Resistance in Glioblastoma via Upregulating the FUS/MDM2 Ubiquitination Axis

Background

LncRNAs have been shown to play essential roles in cancer therapeutic response. However, the detailed mechanism of lncRNAs in temozolomide (TMZ) resistance in glioblastoma (GBM) remain to be elucidated.

Methods

To elucidate the mechanism maintaining TMZ resistance, we constructed two TMZ-resistant GBM cell lines (T98G-R/U118-R). LncRNAs from four public datasets were reanalyzed, and the candidate lncRNA ADAMTS9-AS2 was evaluated in TMZ-treated GBM patients and in vitro cell lines.

Results

Reanalysis of lncRNA expression profiles identified ADAMTS9-AS2 as significantly overexpressed in TMZ-resistant GBM cells and as positively associated with the IC₅₀ of TMZ in GBM cells. Overexpression of ADAMTS9-AS2 was also significantly associated with poor TMZ response and shorter progression-free survival (PFS) in TMZ-treated GBM patients. Knockdown of ADAMTS9-AS2 inhibited proliferation and attenuated the IC₅₀ of TMZ, as well as mitigating invasion and migration in TMZ-resistant GBM cells. Subsequent investigations indicated that reduced expression of ADAMTS9-AS2 significantly suppressed expression of the FUS protein, which was predicted as a direct substrate of ADAMTS9-AS2. Expression trends of FUS were directly correlated with those of ADAMTS9-AS2, as shown by increasing concentrations and prolonged treatment with TMZ. RNA pull-down and RIP assays indicated that both endogenous and exogenous ADAMTS9-AS2 directly binds to the RRM and Znf_RanBP2 domains of FUS, consequently increasing FUS protein expression. Knockdown of ADAMTS9-AS2 reduced the half-life of FUS and decreased FUS protein stability via K48 ubiquitin degradation. Moreover, the E3 ubiquitin-protein ligase MDM2 interacts with and down regulates FUS, while the RRM and Znf_RanBP2 domains of FUS facilitate its binding with MDM2. ADAMTS9-AS2 decreased the interaction between MDM2 and FUS, which mediates FUS K48 ubiquitination. Additionally, knockdown of the ADAMTS9-AS2/FUS signaling axis significantly alleviated progression and metastasis in TMZ-resistant cells.

Conclusion

ADAMTS9-AS2 possessed a novel function that promotes TMZ resistance via upregulating the FUS/MDM2 axis in GBM cells. The RRM or Znf_RanBP2 domains of FUS facilitate the combination of ADAMTS9-AS2 and FUS, competitively inhibiting MDM2-dependent FUS K48 ubiquitination and resulting in enhanced FUS stability and TMZ resistance. Our results suggest that the ADAMTS9-AS2/FUS/MDM2 axis may represent a suitable prognostic biomarker and a potential target in TMZ-resistant GBM therapy.

Clinical prognostic value of isocitrate dehydrogenase mutation, O-6-methylguanine-DNA methyltransferase promoter methylation, and 1p19q co-deletion in glioma patients

Background

Gliomas are the most frequently occurring malignant brain cancers. Recently, isocitrate dehydrogenase (IDH) mutations, O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation, and 1p/19q co-deletion have been suggested to indicate a favorable prognosis in gliomas. However, the clinical prognostic value of these genetic tests in human gliomas is not fully understood.

Methods

We included glioma patients who accepted genetic testing including IDH, MGMT and 1p/19q at Xiangya Hospital, Central South University in China (Jan 2015 to Jun 2017) and further analyzed the effect of the above gene states in high-grade gliomas.

Results

In 103 high-grade glioma patients, IDH mutation, MGMT promoter methylation, and 1p/19q co-deletion had better progression-free survival (PFS) than IDH wild-type (P=0.005), MGMT unmethylated promoter (P=0.002), and without 1p19q co-deletion (P=0.008), respectively. Additionally, we classified the above gliomas into 5 molecular groups, triple-positive, IDH mutation and MGMT methylation, methylation in MGMT only, mutation in IDH only, and triple-negative, according to characteristics of recruited patients. We found that triple-positive gliomas had better PFS than triple-negative cases in high-grade patients (P=0.016). Moreover, the IDH mutation and MGMT methylation groups had prolonged PFS compared to triple-negative (P=0.029).

Conclusions

Our study reinforced the clinical value of biomarkers, including 1p/19q co-deletion, IDH mutation, and the most prominent MGMT methylation, as previously described in glioma prognosis. Further, triple-negative patients have poorer PFS, indicating that the states of these genes can be divided into subgroups as a potential prognostic marker for clinical treatment, which requires a larger, multicenter study to testify.

Identification of key candidate genes and pathways in glioblastoma by integrated bioinformatical analysis

Glioblastoma (GBM), characterized by high morbidity and mortality, is one of the most common lethal diseases worldwide. To identify the molecular mechanisms that contribute to the development of GBM, three cohort profile datasets (GSE50161, GSE90598 and GSE104291) were integrated and thoroughly analyzed; these datasets included 57 GBM cases and 22 cases of normal brain tissue. The current study identified differentially expressed genes (DEGs), and analyzed potential candidate genes and pathways. Additionally, a DEGs-associated protein-protein interaction (PPI) network was established for further investigation. Then, the hub genes associated with prognosis were identified using a Kaplan-Meier analysis based on The Cancer Genome Atlas database. Firstly, the current study identified 378 consistent DEGs (240 upregulated and 138 downregulated). Secondly, a cluster analysis of the DEGs was performed based on functions of the DEGs and signaling pathways were analyzed using the enrichment analysis tool on DAVID. Thirdly, 245 DEGs were identified using PPI network analysis. Among them, two co-expression modules comprising of 30 and 27 genes, respectively, and 35 hub genes were identified using Cytoscape MCODE. Finally, Kaplan-Meier analysis of the hub genes revealed that the increased expression of calcium-binding protein 1 (CABP1) was negatively associated with relapse-free survival. To summarize, all enriched Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways may participate in mechanisms underlying GBM occurrence and progression, however further studies are required. CABP1 may be a key gene associated with the biological process of GBM development and may be involved in a crucial mechanism of GBM progression.

Expression and clinical significance of CPS1 in glioblastoma multiforme

Carbamoyl phosphate synthetase-1 (CPS1), the first rate-limiting mitochondrial enzyme in the urea cycle, regulates proliferation and differentiation during tumor progression. However, the detailed function of CPS1 in glioblastoma Multiforme (GBM) is still unclear. Here, we highlight mechanisms for CPS1 upregulation and the effects of upregulated CPS1 on GBM tumorigenesis. The transcriptome data from several public databases, such as Oncomine and GEPIA, revealed that CPS1 transcriptional level was significantly upregulated in GBM tissues and cells. Moreover, CPS1 was hypomethylated in GBM tissues. The Wanderer database, linked to the Cancer Genome Atlas (TCGA), showed the association between CPS1 expression or its methylation values and the clinicopathological parameters in GBM patients. Our work fully demonstrated that CPS1 expression was upregulated in GBM and this gene could be used as a potential diagnostic and prognosis indicator for GBM.

Long noncoding RNA HOXD-AS2 regulates cell cycle to promote glioma progression

Now, numerous exciting findings have been found that long noncoding RNAs (lncRNAs) play a vital role in cancer malignant progression. However, their potential involvement in glioma is not well understood. Here, we performed a high-throughput microarray to detect the lncRNA expression profiles between glioma cell lines and normal astrocyte cell lines. HOXD-AS2 was increased in glioma cells and it was associated with glioma grade and poor prognosis. Loss of HOXD-AS2 can inhibit glioma cell growth by inducing cell-cycle G1 arrest in vitro. The proliferation of glioma was inhibited followed by knocking down the expression of HOXD-AS2 not only in subcutaneous injection model but also in orthotopic implantation model. These findings indicate that HOXD-AS2 promotes the glioma progression and may serve as a potential target for glioma diagnosis and therapy.

Roles of Non-Coding RNAs in Normal Human Brain Development, Brain Tumor, and Neuropsychiatric Disorders

One of modern biology’s great surprises is that the human genome encodes only ~20,000 protein-coding genes, which represents less than 2% of the total genome sequence, and the majority of them are transcribed into non-coding RNAs (ncRNAs). Increasing evidence has shown that ncRNAs, including miRNAs, long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), play important roles in regulating a wide range of biological processes of the human brain. They not only regulate the pathogenesis of brain tumors, but also the development of neuropsychiatric diseases. This review provides an integrated overview of the roles of ncRNAs in normal human brain function, brain tumor development, and neuropsychiatric disease. We discussed the functions and molecular mechanisms of miRNAs, lncRNAs, and circRNAs in normal brain function and glioma, respectively, including those in exosome vesicles that can act as a molecular information carrier. We also discussed the regulatory roles of ncRNAs in the development of neuropsychiatric diseases. Lastly, we summarized the currently available platforms and tools that can be used for ncRNA identification and functional exploration in human diseases. This study will provide comprehensive insights for the roles of ncRNAs in human brain function and disease.

The effects and the mechanisms of autophagy on the cancer-associated fibroblasts in cancer

Cancer-associated fibroblasts (CAFs) plays an essential role in cancer cell growth, metabolism and immunoreaction. Autophagy is an intracellular self-degradative process that balances cell energy source and regulates tissue homeostasis. Targeting autophagy has gained interest with multiple preclinical and clinical trials, such as the pharmacological inhibitor chloroquine or the inducer rapamycin, especially in exploiting its ability to modulate the secretory capability of CAFs to enhance drug delivery or inhibit it to prevent its influence on cancer cell chemoresistance. In this review, we summarize the reports on autophagy in cancer-associated fibroblasts by detailing the mechanism and role of autophagy in CAFs, including the hypoxic-autophagy positive feedback cycle, the metabolic cross-talk between CAFs and tumors induced by autophagy, CAFs secreted cytokines promote cancer survival by secretory autophagy, CAFs autophagy-induced EMT, stemness, senescence and treatment sensitivity, as well as the research of antitumor chemicals, miRNAs and lncRNAs. Additionally, we discuss the evidence of molecules in CAFs that are relevant to autophagy and the contribution to sensitive treatments as a potential target for cancer treatment.

ZEB1-AS1 is associated with poor prognosis in non-small-cell lung cancer and influences cell migration and apoptosis by repressing ID1

Long non-coding RNAs (lncRNAs) have been reported to play a vital role in non-small-cell lung cancer (NSCLC). ZEB1-AS1 overexpression predicts a poor prognosis in osteosarcoma and colorectal cancers. In the current study, we determined the clinical significance and prognostic value of ZEB1-AS1 in patients with NSCLC. The expression of ZEB1-AS1 and inhibitor of differentiation-1 (ID1) was measured using qRT-PCR and Western blot. Cell growth, migration, and invasion were determined using colony formation assays, Transwell assay, and flow cytometry, respectively. Tumor growth was determined with a xenograft model. ZEB1-AS1 was significantly up-regulated in NSCLC tissues compared with normal samples. ZEB1-AS1 overexpression was significantly associated with advanced tumor, lymph node, and metastases (TNM) stage and tumor size, as well as poorer overall survival. Moreover, ZEB1-AS1 knockdown inhibited NSCLC cell proliferation and migration, and promoted cell apoptosis. In addition, a chromatin immunoprecipitation assay revealed that ZEB1-AS1 interacted with STAT3, thereby repressing ID1 expression. Furthermore, rescue experiments indicated that ZEB1-AS1 functioned as an oncogene partly by repressing ID1 in NSCLC cells. Taken together, our findings indicate that ZEB1-AS1 serves as a promising therapeutic target to predict the prognosis of NSCLC.

Functional Long Noncoding RNAs (lncRNAs) in Clear Cell Kidney Carcinoma Revealed by Reconstruction and Comprehensive Analysis of the lncRNA-miRNA-mRNA Regulatory Network

BACKGROUND A variety of treatment strategies have been developed for clear cell kidney carcinoma (KIRC); however, there is still a need for effective therapeutic targets and prognostic molecular biomarkers. Given that long noncoding RNAs (lncRNAs) has been emerging as an important regulator in tumorigenesis, we explored potential functional lncRNAs in KIRC by comprehensively analyzing the lncRNA-miRNA-mRNA regulatory network with bioinformatics processing tools. MATERIAL AND METHODS RNA-seq/miRNA-seq data of KIRC in The Cancer Genome Atlas (TCGA) were obtained and analyzed. The "edgeR" package in R software was used to identify differentially expressed lncRNAs (DElncRNAs, differentially expressed long noncoding RNAs), miRNAs (DEmiRNAs, differentially expressed micro RNAs), and mRNAs (DEmRNAs, differentially expressed messenger RNAs) in KIRC and normal samples. A global triple network was conducted based on the competing endogenous RNA (ceRNA) theory, and survival analysis was conducted by "survival" package in R software. RESULTS A total of 4246 DElncRNAs, 179 DEmiRNAs, and 5758 DEmRNAs were identified, among which a subset of them (321 lncRNAs, 26 miRNAs, and 1068 mRNAs) were found to constitute a global ceRNA network in KIRC. Four lncRNAs (ENTPD3-AS1, FGD5-AS1, LIFR-AS1, and UBAC2-AS1) were revealed to be potential therapeutic targets as well as prognostic biomarkers of KIRC by our extensive functional analysis. CONCLUSIONS We reported here the identification of functional lncRNAs in KIRC via a TCGA data-based bioinformatics analysis. We believe that this study might contribute to improving the comprehension of the lncRNA-mediated ceRNA regulatory mechanisms in the tumorigenesis of KIRC. Meanwhile, our results suggested that 4 lncRNAs might act as potential therapeutic targets or candidate prognostic biomarkers in KIRC.

Potential Epigenetic-Based Therapeutic Targets for Glioma

Glioma is characterized by a high recurrence rate, short survival times, high rates of mortality and treatment difficulties. Surgery, chemotherapy and radiation (RT) are the standard treatments, but outcomes rarely improve even after treatment. With the advancement of molecular pathology, recent studies have found that the development of glioma is closely related to various epigenetic phenomena, including DNA methylation, abnormal microRNA (miRNA), chromatin remodeling and histone modifications. Owing to the reversibility of epigenetic modifications, the proteins and genes that regulate these changes have become new targets in the treatment of glioma. In this review, we present a summary of the potential therapeutic targets of glioma and related effective treating drugs from the four aspects mentioned above. We further illustrate how epigenetic mechanisms dynamically regulate the pathogenesis and discuss the challenges of glioma treatment. Currently, among the epigenetic treatments, DNA methyltransferase (DNMT) inhibitors and histone deacetylase inhibitors (HDACIs) can be used for the treatment of tumors, either individually or in combination. In the treatment of glioma, only HDACIs remain a good option and they provide new directions for the treatment. Due to the complicated pathogenesis of glioma, epigenetic applications to glioma clinical treatment are still limited.

Long noncoding RNA AC003092.1 promotes temozolomide chemosensitivity through miR-195/TFPI-2 signaling modulation in glioblastoma

Temozolomide (TMZ) and radiation therapy combination for glioblastoma (GB) patients has been considered as the most effective therapy after surgical procedure. However, the overall clinical prognosis remains unsatisfactory due to intrinsic or developing resistance to TMZ. Recently, increasing evidence suggested that long noncoding RNAs (lncRNAs) play a critical role in various biological processes of tumors, and have been implicated in resistance to various drugs. However, the role of lncRNAs in TMZ resistance is poorly understood. Here, we found that the expression of lncRNA AC003092.1 was markedly decreased in TMZ resistance (TR) of GB cells (U87TR and U251TR) compared with their parental cells (U87 and U251). In patients with glioma, low levels of lncRNA AC003092.1 were correlated with increased TMZ resistance, higher risk of relapse, and poor prognosis. Overexpression of lncRNA AC003092.1 enhances TMZ sensitivity, facilitates cell apoptosis, and inhibits cell proliferation in TMZ-resistant GB cells. In addition, we identified that lncRNA AC003092.1 regulates TMZ chemosensitivity through TFPI-2-mediated cell apoptosis in vitro and in vivo. Mechanistically, further investigation revealed that lncRNA AC003092.1 regulates TFPI-2 expression through miR-195 in GB. Taken together, these data suggest that lncRNA AC003092.1 could inhibit the function of miR-195 by acting as an endogenous CeRNA, leading to increased expression of TFPI-2; this promotes TMZ-induced apoptosis, thereby making GB cells more sensitive to TMZ. Our findings indicate that overexpression of lncRNA AC003092.1 may be a potential therapy to overcome TMZ resistance in GB patients.

PR-LncRNA signature regulates glioma cell activity through expression of SOX factors

Long non-coding RNAs (LncRNAs) have emerged as a relevant class of genome regulators involved in a broad range of biological processes and with important roles in tumor initiation and malignant progression. We have previously identified a p53-regulated tumor suppressor signature of LncRNAs (PR-LncRNAs) in colorectal cancer. Our aim was to identify the expression and function of this signature in gliomas. We found that the expression of the four PR-LncRNAs tested was high in human low-grade glioma samples and diminished with increasing grade of disease, being the lowest in glioblastoma samples. Functional assays demonstrated that PR-LncRNA silencing increased glioma cell proliferation and oncosphere formation. Mechanistically, we found an inverse correlation between PR-LncRNA expression and SOX1, SOX2 and SOX9 stem cell factors in human glioma biopsies and in glioma cells in vitro. Moreover, knock-down of SOX activity abolished the effect of PR-LncRNA silencing in glioma cell activity. In conclusion, our results demonstrate that the expression and function of PR-LncRNAs are significantly altered in gliomagenesis and that their activity is mediated by SOX factors. These results may provide important insights into the mechanisms responsible for glioblastoma pathogenesis.

Long non-coding RNAs in brain tumours: Focus on recent epigenetic findings in glioma

Glioma biology is a major focus in tumour research, primarily due to the aggressiveness and high mortality rate of its most aggressive form, glioblastoma. Progress in understanding the molecular mechanisms behind poor prognosis of glioblastoma, regardless of treatment approaches, has changed the classification of brain tumours after nearly 100 years of relying on anatomopathological criteria. Expanding knowledge in genetic, epigenetic and translational medicine is also beginning to contribute to further elucidating molecular dysregulation in glioma. Long non‐coding RNAs (lncRNAs) and their main representatives, large intergenic non‐coding RNAs (lincRNAs), have recently been under scrutiny in glioma research, revealing novel mechanisms of pathogenesis and reinforcing others. Among those confirmed was the reactivation of events significant for foetal brain development and neuronal commitment. Novel mechanisms of tumour suppression and activation of stem‐like behaviour in tumour cells have also been examined. Interestingly, these processes involve lncRNAs that are present both during normal brain development and in brain malignancies and their reactivation might be explained by epigenetic mechanisms, which we discuss in detail in the present review. In addition, the review discusses the lncRNAs‐induced changes, as well as epigenetic changes that are consequential for tumour formation, affecting, in turn, the expression of various types of lncRNAs.

Lico A Causes ER Stress and Apoptosis via Up-Regulating miR-144-3p in Human Lung Cancer Cell Line H292

During our study on the bioactivities of natural flavonoids, we found that the total flavonoids (TFs) and the main constituent of it, licochalcone A (lico A), activated unfolded protein response (UPR) and induced autophagy and thereby apoptosis in H292 cells. MicroRNAs, such as the tumor repressor miR-144-3p, were reported to be differentially expressed in lung cancer cells and were linked to ER stress, autophagy, and apoptosis. However, the underlying miRNA-based mechanism for lico A modulating proliferation, autophagy and apoptosis in lung cancer cells is elusive. In this study, we found that miR-144-3p was down-regulated in H292 cells comparing to normal embryonic lung cells WI-38, and lico A (10 μM) could increase miR-144-3p level in H292 cells. Knockdown of miR-144-3p significantly abrogated the apoptosis and proliferation-inhibiting effects of lico A, and lico A could enhance the proliferation-inhibiting effect and apoptosis induced by miR-144-3p overexpression. Moreover, overexpression miR-144-3p could induce ER stress by down-regulating Nrf2, and lico A enhanced the Nrf2 down-regulation caused by miR-144-3p overexpression. Co-transfection experiments showed that lico A potentially increased the dicing of pre-miR-144 so as to increase the mature miR-144-3p level. Interestingly, high level of lico A (40 μM) up-regulated CHOP protein, but failed to increase the downstream genes levels of CHOP, including Bim and Bcl-2 in H292 cells. Docking studies indicated that CHOP-mediated pathway was potentially blocked by high dose of lico A. Our results suggested that lico A could cause UPR, autophagy and apoptosis, and the underlying mechanism involved up-regulation of miR-144-3p, and increased lico A level would also increase the potential for lico A inhibiting CHOP-dependent apoptosis in H292 cells.

Exploring Long Noncoding RNAs in Glioblastoma: Regulatory Mechanisms and Clinical Potentials

Gliomas are primary brain tumors presumably derived from glial cells. The WHO grade IV glioblastoma (GBM), characterized by rapid cell proliferation, easily recrudescent, high morbidity, and mortality, is the most common, devastating, and lethal gliomas. Molecular mechanisms underlying the pathogenesis and progression of GBMs with potential diagnostic and therapeutic value have been explored industriously. With the advent of high-throughput technologies, numerous long noncoding RNAs (lncRNAs) aberrantly expressed in GBMs were discovered recently, some of them probably involved in GBM initiation, malignant progression, relapse and resistant to therapy, or showing diagnostic and prognostic value. In this review, we summarized the profile of lncRNAs that has been extensively investigated in glioma research, with a focus on their regulatory mechanisms. Then, their diagnostic, prognostic, and therapeutic implications were also discussed.

Long noncoding RNA MIAT regulates apoptosis and the apoptotic response to chemotherapeutic agents in breast cancer cell lines

The long noncoding RNA myocardial infarction associated transcript (MIAT) is involved in a number of diseases, including myocardial infarction and diabetic retinopathy. Emerging evidence suggests that MIAT expression levels are increased in different type of cancers, including breast cancer. In the present study, we further evaluated the role of MIAT in breast cancer and investigated the consequences of its silencing on breast cancer response to chemotherapeutic agents. Expression levels of MIAT mRNA in breast cancer were determined using TissueScan™ Breast Cancer cDNA Arrays. Breast cancer cell lines were transfected with MIAT specific siRNAs, with silencing confirmed using RT-qPCR and the effects on breast cancer cell survival and response to different apoptotic stimuli determined. MIAT transcript levels were significantly elevated in breast cancer samples. Such increase was specific to the early stages of the disease, ER, PR +ve, HER –ve, and triple negative breast cancer samples. Silencing of MIAT induced growth arrest and increased basal apoptosis. Reduced levels of MIAT augmented the apoptotic response of breast cancer cells to a wide range of apoptotic stimuli. Our results also showed that MIAT down-regulation was associated with a decrease in OCT4 mRNA, suggesting the existence of a MIAT/OCT4 regulatory loop, similar to that observed in malignant mature B cells. Taken together with the recent demonstration of oncogene characteristics, our observations suggest that MIAT plays an important role in breast tumorigenesis. Strategies to decrease MIAT expression levels may improve sensitivity to therapy in breast cancer by enhancing the apoptotic responses to conventional chemotherapies.