Long noncoding RNA MNX1‐AS1 contributes to lung cancer progression through the miR‐527/BRF2 pathway

The role of EMG1 in lung adenocarcinoma progression: Implications for prognosis and immune cell infiltration

BACKGROUND AND AIMS

Lung adenocarcinoma (LUAD) is the most common and aggressive cancer with a high incidence. N1-specific pseudouridine methyltransferase (EMG1), a highly conserved nucleolus protein, plays an important role in the biological development of ribosomes. However, the role of EMG1 in the progression of LUAD is still unclear.

METHODS

The expression of EMG1 in LUAD cells, and LUAD tissues, and adjacent noncancerous tissues was quantified using real-time polymerase chain reaction (PCR) and western blotting. The roles of EMG1 in LUAD cell proliferation, migration, invasion and tumorigenicity were explored in vitro and in vivo. Western blot analysis to underlying molecular mechanism of EMG1 regulating the biological function of LUAD. EMG1 expression and its impact on tumor prognosis were analyzed using a range of databases including GEPIA, UALCAN, cBioPortal, LinkedOmics, and Kaplan-Meier Plotter.

RESULTS

EMG1 expression was elevated in LUAD patients compared to normal tissues, and EMG1 expression was strongly correlated with prognosis in LUAD patients. EMG1 expression correlated with age, gender, N stage, T stage, and pathologic stage. EMG1 expression was strongly positively correlated with MRPL51, PHB2, SNRPG, ATP5MD, and TPI1, and strongly negatively correlated with MACF1, DOCK9, RAPGEF2, SYNJ1, and KIDINS220, the major enrichment pathways for EMG1 and related genes include Cell cycle, DNA Replication and Pathways in cancer signaling pathways. EMG1 expression level was significantly increased in LUAD cell lines and tissues. Knockdown of EMG1 could inhibit LUAD cell proliferation, migration, invasion, and tumorigenicity. Besides, EMG1 overexpression could promote LUAD cell proliferation, migration, and invasion. High expression of EMG1 predicts poor prognosis in LUAD patients, and EMG1 may play an oncogenic role in the tumor microenvironment by participating in the infiltration of LUAD immune cells.

CONCLUSIONS

EMG1 regulated various functions in LUAD by directly mediating Akt/mTOR/p70s6k signaling pathways activation. The results suggest that EMG1 may be a novel biomarker for assessing prognosis and immune cell infiltration in LUAD.

Identification of a methyltransferase-related long noncoding RNA signature as a novel prognosis biomarker for lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) accounts for a high proportion of tumor deaths globally, while methyltransferase-related lncRNAs in LUAD were poorly studied.

METHODS

In our study, we focused on two distinct cohorts, TCGA-LUAD and GSE3021, to establish a signature of methyltransferase-related long non-coding RNAs (MeRlncRNAs) in LUAD. We employed univariate Cox and LASSO regression analyses as our main analytical tools. The GSE30219 cohort served as the validation cohort for our findings. Furthermore, to explore the differential pathway enrichments between groups stratified by risk, we utilized Gene Set Enrichment Analysis (GSEA). Additionally, single-sample GSEA (ssGSEA) was conducted to assess the immune infiltration landscape within each sample. Reverse transcription quantitative PCR (RT-qPCR) was also performed to verify the expression of prognostic lncRNAs in both clinically normal and LUAD samples.

RESULTS

In LUAD, we identified a set of 32 MeRlncRNAs. We further narrowed our focus to six prognostic lncRNAs to develop gene signatures. The TCGA-LUAD cohort and GSE30219 were utilized to validate the risk score model derived from these signatures. Our analysis showed that the risk score served as an independent prognostic factor, linked to immune-related pathways. Additionally, the analysis of immune infiltration revealed that the immune landscape in high-risk groups was suppressed, which could contribute to poorer prognoses. We also constructed a regulatory network comprising 6 prognostic lncRNAs, 19 miRNAs, and 21 mRNAs. Confirmatory RT-qPCR results aligned with public database findings, verifying the expression of these prognostic lncRNAs in the samples.

CONCLUSION

The prognostic gene signature of LUAD associated with MeRlncRNAs that we provided, may offer us a comprehensive picture of the prognosis prediction for LUAD patients.

Various LncRNA Mechanisms in Gene Regulation Involving miRNAs or RNA-Binding Proteins in Non-Small-Cell Lung Cancer: Main Signaling Pathways and Networks

Long non-coding RNAs (lncRNAs) are crucial players in the pathogenesis of non-small-cell lung cancer (NSCLC). A competing binding of lncRNAs and mRNAs with microRNAs (miRNAs) is one of the most common mechanisms of gene regulation by lncRNAs in NSCLC, which has been extensively researched in the last two decades. However, alternative mechanisms that do not depend on miRNAs have also been reported. Among them, the most intriguing mechanism is mediated by RNA-binding proteins (RBPs) such as IGF2BP1/2/3, YTHDF1, HuR, and FBL, which increase the stability of target mRNAs. IGF2BP2 and YTHDF1 may also be involved in m6A modification of lncRNAs or target mRNAs. Some lncRNAs, such as DLGAP1-AS2, MALAT1, MNX1-AS1, and SNHG12, are involved in several mechanisms depending on the target: lncRNA/miRNA/mRNA interactome and through RBP. The target protein sets selected here were then analyzed using the DAVID database to identify the pathways overrepresented by KEGG, Wikipathways, and the Reactome pathway. Using the STRING website, we assessed interactions between the target proteins and built networks. Our analysis revealed that the JAK-STAT and Hippo signaling pathways, cytokine pathways, the VEGFA-VEGFR2 pathway, mechanisms of cell cycle regulation, and neovascularization are the most relevant to the effect of lncRNA on NSCLC.

Potential plasma microRNAs signature miR-190b-5p, miR-215-5p and miR-527 as non-invasive biomarkers for prostate cancer

BackgroundProstate cancer (PCa) is the most prevalent (20%) pathological cancer among males globally. MicroRNAs (miRNAs) are short (19-22 nucleotide), conserved, noncoding molecules that regulate post-transcriptional processes either by repressing or degrading mRNA or by translation inhibition binding to complementary sites on mRNA. The goal of this study was to find out whether differentially expressed microRNA (DEM) could be used as a potential marker in the prognosis and diagnosis of PCa.MethodologyThe miRNAs profiling was done both from plasma and tissue samples of the same PCa patient (n = 3) by real-time quantitative PCR (qRT-PCR) and compared with BPH (benign prostatic hyperplasia) patients (n = 3) as controls and further validation of selected miRNAs.ResultsWe found 55 significant overexpressed DEMs, 44 significant underexpressed DEMs in plasma and 6 significant overexpressed DEMs, 27 significant underexpressed DEMs in tissue compared between PCa and BPH. Furthermore, there were eight miRNAs namely miR-190b, miR-215, miR-300, miR-329, miR-504, miR-525-3p, miR-527, miR-548a-3p found to be significantly differentially expressed in plasma and tissue samples via profiling, however only three showed concordant expression. After validation, miR-190b-5p were shown to be significantly downexpressed with fold changes of 0.4177 (p value - 0.0072) and 0.7264 (p value - 0.0143) in plasma and tissue samples, respectively. The expression of miR-215-5p was shown to be significantly overexpressed with fold change of 1.820 (p - 0.0016) and 1.476 (p - 0.0407) in plasma and tissue samples, respectively. Furthermore, miR-527 was shown to be significantly downexpressed with fold changes of 0.6018 (p - 0.0095) and 0.6917 (p - 0.0155) in plasma and tissue samples, respectively.ConclusionAccording to our findings, plasma miR-190b-5p, miR-215-5p, miR-527 levels alteration is consistently linked with PCa tissue. For establishing significant miRNAs as biomarkers, additional research of a larger population is needed.

Characteristics and Prognosis of 8p11.23-Amplified Squamous Lung Carcinomas

BACKGROUND

Copy number alterations are common genetic lesions in cancer. In squamous non-small cell lung carcinomas, the most common copy-number-altered loci are at chromosomes 3q26-27 and 8p11.23. The genes that may be drivers in squamous lung cancers with 8p11.23 amplifications are unclear.

METHODS

Data pertaining to copy number alterations, mRNA expression and protein expression of genes located in the 8p11.23 amplified region were extracted from various sources including The Cancer Genome Atlas, the Human Protein Atlas and the Kaplan Meier Plotter. Genomic data were analyzed using the cBioportal platform. Survival analysis of cases with amplifications compared to nonamplified cases was performed using the Kaplan Meier Plotter platform.

RESULTS

The 8p11.23 locus is amplified in 11.5% to 17.7% of squamous lung carcinomas. The most frequently amplified genes include NSD3, FGFR1 and LETM2. Only some of the amplified genes present concomitant overexpression at the mRNA level. These include NSD3, PLPP5, DDHD2, LSM1 and ASH2L, while other genes display lower levels of correlation, and still, some genes in the locus show no mRNA overexpression compared with copy-neutral samples. The protein products of most locus genes are expressed in squamous lung cancers. No significant difference in overall survival in 8p11.23-amplified squamous cell lung cancers versus nonamplified cancers is observed. In addition, there is no adverse effect of mRNA overexpression for relapse-free survival of any of the amplified genes.

CONCLUSION

Several genes that are part of the commonly amplified locus 8p11.23 in squamous lung carcinomas are putative oncogenic candidates. A subset of genes of the centromeric part of the locus, which is amplified more commonly than the telomeric part, show high concomitant mRNA expression.

Activation of MYO1G by lncRNA MNX1-AS1 Drives the Progression in Lung Cancer

Lung cancer represents the most prevalent cancer worldwide and causes the death of many patients. Cancer stem cells (CSCs), a subpopulation of cancer cells, have the capacities of self-renewal, unlimited proliferation, and multiple differentiation potential. The purpose of this study was to explore the potential role of long noncoding RNA (lncRNA) MNX1-AS1 on maintaining the stemness of CSC in lung cancer. CSCs were firstly sorted by flow cytometry. After the determination of the target of the present study using Gene Expression Omnibus dataset, MNX1-AS1was found to be highly expressed in lung cancer tissues and cells. Deletion of MNX1-AS1 inhibited proliferation, migration, invasion and sphere-forming abilities of CSC. Furthermore, subcellular fractionation, fluorescence in situ hybridization, RNA immunoprecipitation, and dual-luciferase experiments demonstrated that MNX1-AS1 recruited the transcription factor POU domain class 2 transcription factor 2 (POU2F2) to the nucleus and activated the myosin IG (MYO1G) expression. MYO1G overexpression partially reversed the si-MNX1-AS1-decreased stemness of CSCs. Finally, MNX1-AS1 suppression significantly repressed the growth of xenografts in vivo. Our study highlights the importance of the MNX1-AS1/POU2F2/MYO1G axis in stem cell-like properties of lung cancer cells.

MNX1-AS1, a c-Myc induced lncRNA, promotes the Warburg effect by regulating PKM2 nuclear translocation

BACKGROUND

Altered glycolysis is the most fundamental metabolic change associated with the Warburg effect. Some glycolytic enzymes such as PKM2, the dominant pyruvate kinase in cancer cells, have been shown to engage in non-glycolytic functions that contribute to tumor metabolism. However, the precise mechanisms are not completely understood.

METHODS

The role of MNX1-AS1 in hepatocellular carcinoma progression was assessed both in vitro and in vivo. Northern blotting, RNA pulldown, mass spectrometry, RNA-binding protein immunoprecipitation, ChIP, luciferase reporter assays, RNA FISH and immunofluorescence staining were used to explore the detail molecular mechanism of MNX1-AS1 in hepatocellular carcinoma (HCC).

RESULTS

Here we dissect how MNX1-AS1, a long non-coding RNA (lncRNA), reinforces the Warburg effect through facilitating the non-glycolytic actions of PKM2 in the cell nucleus. We found that MNX1-AS1 expression was frequently overexpressed in HCC-derived cell lines and tissues compared to their normal hepatic cell counterparts, a finding consistent with its status as pan-cancer expressed lncRNA. In the context of HCC, we show MNX1-AS1 acts as a scaffold to promote interactions between PKM2 and importin α5. In response to EGFR activation, the resulting ternary complex drives the translocation of PKM2 into the nucleus. In consequence, glycolytic pathway components including key mediators of the Warburg effect (LDHA, GLUT1 and PDK1) are upregulated though the coactivator function of PKM2. Manipulating MNX1-AS1 elicited robust effects on glycolysis associated with marked changes in HCC growth in vitro and in xenograft models, indicative of the significant contribution of MNX1-AS1 to tumorigenic phenotypes. Moreover, while MNX1-AS1 expression is driven by c-Myc, its actions associated with PKM2 were shown to be downstream and independent of c-Myc.

CONCLUSIONS

Given the status of MNX1-AS1 as a pan-cancer upregulated lncRNA, this implicitly highlights the potential of targeting MNX1-AS1 to selectively counter the Warburg effect in a range of tumor types.

Pan-Cancer Analysis Identifies MNX1 and Associated Antisense Transcripts as Biomarkers for Cancer

The identification of diagnostic and prognostic biomarkers is a major objective in improving clinical outcomes in cancer, which has been facilitated by the availability of high-throughput gene expression data. A growing interest in non-coding genomic regions has identified dysregulation of long non-coding RNAs (lncRNAs) in several malignancies, suggesting a potential use as biomarkers. In this study, we leveraged data from large-scale sequencing projects to uncover the expression patterns of the MNX1 gene and its associated lncRNAs MNX1-AS1 and MNX1-AS2 in solid tumours. Despite many reports describing MNX1 overexpression in several cancers, limited studies exist on MNX1-AS1 and MNX1-AS2 and their potential as biomarkers. By employing clustering methods to visualise multi-gene relationships, we identified a discriminative power of the three genes in distinguishing tumour vs. normal samples in several cancers of the gastrointestinal tract and reproductive systems, as well as in discerning oesophageal and testicular cancer histological subtypes. Notably, the expressions of MNX1 and its antisenses also correlated with clinical features and endpoints, uncovering previously unreported associations. This work highlights the advantages of using combinatory expression patterns of non-coding transcripts of differentially expressed genes as clinical evaluators and identifies MNX1, MNX1-AS1, and MNX1-AS2 expressions as robust candidate biomarkers for clinical applications.

MicroRNAs, Tristetraprolin Family Members and HuR: A Complex Interplay Controlling Cancer-Related Processes

Simple Summary

AU-rich Element Binding Proteins (AUBPs) represent important post-transcriptional regulators of gene expression by regulating mRNA decay and/or translation. Importantly, AUBPs can interfere with microRNA-dependent regulation by (i) competing with the same binding sites on mRNA targets, (ii) sequestering miRNAs, thereby preventing their binding to their specific targets or (iii) promoting miRNA-dependent regulation. These data highlight a new paradigm where both miRNA and RNA binding proteins form a complex regulatory network involved in physiological and pathological processes. However, this interplay is still poorly considered, and our current models do not integrate this level of complexity, thus potentially giving misleading interpretations regarding the role of these regulators in human cancers. This review summarizes the current knowledge regarding the crosstalks existing between HuR, tristetraprolin family members and microRNA-dependent regulation.

Abstract

MicroRNAs represent the most characterized post-transcriptional regulators of gene expression. Their altered expression importantly contributes to the development of a wide range of metabolic and inflammatory diseases but also cancers. Accordingly, a myriad of studies has suggested novel therapeutic approaches aiming at inhibiting or restoring the expression of miRNAs in human diseases. However, the influence of other trans-acting factors, such as long-noncoding RNAs or RNA-Binding-Proteins, which compete, interfere, or cooperate with miRNAs-dependent functions, indicate that this regulatory mechanism is much more complex than initially thought, thus questioning the current models considering individuals regulators. In this review, we discuss the interplay existing between miRNAs and the AU-Rich Element Binding Proteins (AUBPs), HuR and tristetraprolin family members (TTP, BRF1 and BRF2), which importantly control the fate of mRNA and whose alterations have also been associated with the development of a wide range of chronic disorders and cancers. Deciphering the interplay between these proteins and miRNAs represents an important challenge to fully characterize the post-transcriptional regulation of pro-tumorigenic processes and design new and efficient therapeutic approaches.

lncRNA MNX1‑AS1 promotes prostate cancer progression through regulating miR‑2113/MDM2 axis

A growing number of dysregulated long non-coding (lnc)RNAs have been verified to serve an essential role in human prostate cancer. However, the underlying mechanisms of lncRNA MNX1 Antisense RNA 1 (MNX1-AS1) in prostate cancer has not been explored. Therefore, the present study aimed to explore the function of MNX1-AS1 in prostate cancer tumorigenesis and investigate the in-depth mechanism. The expression of MNX1-AS1, microRNA (miR)-2113 and murine double min 2 (MDM2) in prostate cancer tissues and corresponding normal tissues were assessed by reverse transcription-quantitative PCR. The protein expression levels of MDM2 were detected by western blotting. LNCaP and PC-3 cells were transfected with short hairpin (sh)-MNX1-AS1, miR-2113 mimics, miR-2113 inhibitor and pCDH-MDM2 vector using Lipofectamine^® 3000. Cell proliferation, migration and invasion abilities were assessed by CCK-8 assay, colony formation and Transwell assay, respectively. Dual luciferase reporter assay was carried out to confirm the putative targets of MNX1-AS1 and miR-2113. Tumor formation experiment in nude mice was applied to evaluate the tumor growth effect of MNX1-AS1 in vivo. The expression of MNX1-AS1 was significantly upregulated in the prostate cancer tissues and cell lines. MNX1-AS1 knockdown suppressed the abilities of cell viability and migration and invasion in vitro and inhibited tumor growth in vivo. Additionally, luciferase reporter assay revealed that MNX1-AS1 could target miR-2113 and negatively interacted with miR-2113 in prostate cancer cells. miR-2113 directly targeted to MDM2 and negatively modulated the expression of MDM2. Rescue assays suggested that the viability, migration and invasion of impaired cells triggered by transfection with sh-MNX1-AS1 alone could be recovered by co-transfection with sh-MNX1-AS1 + miR-2113 inhibitor or sh-MNX1-AS1 + pCDH- MDM2 vector. The present study demonstrated that MNX1-AS1 promoted prostate cancer progression through regulating miR-2113/ MDM2 axis.

LncRNA MNX1-AS1: A novel oncogenic propellant in cancers

To date, recent studies have shown that long non-coding RNAs (lncRNAs) are key players in gene regulation processes involved in cancer pathogenesis. In general, Motor neuron and pancreas homeobox 1-antisense RNA1 (MNX1-AS1) is highly expressed in all cancers as reported so far and exerts oncogenic effects through different mechanisms. In this review, we comprehensively summarize the detailed mechanisms of potential functions of MNX1-AS1 in different cancer types as well as the latest knowledge highlighting the potential of MNX1-AS1 as a therapeutic target for cancer. Aberrant expression of MNX1-AS1 closely correlates with clinicopathological parameters. such as lymphatic metastasis, tumor size, tumor stage, OS and DFS. Thus, MNX1-AS1 can be used as a diagnostic and prognostic biomarker or even a therapeutic prognostic target. This article reviews its function, molecular mechanism and clinical prognosis in various malignancies.

LncRNA MAFG-AS1 Promotes Lung Adenocarcinoma Cell Migration and Invasion by Targeting miR-3196 and Regulating SOX12 Expression

Lung adenocarcinoma (LUAD) patients exhibit poor prognosis, primarily due to metastasis. Emerging studies have demonstrated that long noncoding RNAs (lncRNAs) play critical roles in cancer progression and metastasis besides their physiological function. Here, we investigated the potential role of lncRNA MAF BZIP Transcription Factor G Antisense RNA 1 (MAFG-AS1) in LUAD metastasis by analyzing its expression in The Cancer Genome Atlas (TCGA) LUAD database, and its function in LUAD using in vitro and in vivo experiments. We performed bioinformatics analysis, western blotting, dual-luciferase reporter gene assay, RNA immunoprecipitation (RIP), and rescue assays to reveal the molecular mechanisms underlying MAFG-AS1 function. We observed augmented expression of MAFG-AS1 in LUAD tissues compared with normal adjacent tissues, and its association with poor prognosis. Furthermore, MAFG-AS1 overexpression promoted LUAD cell migration, proliferation, invasion, and epithelial mesenchymal transition (EMT). Besides, MAFG-AS1 also targeted miR-3196 directly by acting as an endogenous sponge, thereby rescuing the inhibition of SOX12, a target of miR-3196. Thus, the rescue assays demonstrated that MAFG-AS1 promotes cell migration, invasion, and EMT by modulating the miR-3196/SOX12 pathway. In conclusion, our findings suggest that MAFG-AS1/miR-3196/SOX12 axis regulates LUAD progression and is a potential therapeutic target for LUAD.

The circular RNA hsa_circ_0001394 promotes hepatocellular carcinoma progression by targeting the miR-527/UBE2A axis

Circular RNAs (circRNAs) have been recognized as significant participants in the progression of different cancers; however, the detailed mechanisms of circRNAs in hepatocellular carcinoma (HCC) remain unclear. In this study, hsa_circ_0001394 was identified by RNA-seq analysis, and hsa_circ_0001394 was determined to be highly expressed in HCC specimens and cell lines. Patients with high expression of hsa_circ_0001394 tended to exhibit poor survival. Increased hsa_circ_0001394 expression in plasma was closely correlated with clinicopathological features including elevated vascular invasion and an advanced TNM stage, as indicated by alpha-fetoprotein (AFP) analysis. Hsa_circ_0001394 promoted the proliferation, migration, and invasion of HCC cells, whereas knockdown of hsa_circ_0001394 inhibited HCC tumorigenesis in vivo. In addition, mechanistic studies showed that miR-527 negatively interacted with hsa_circ_0001394. Furthermore, UBE2A was revealed to serve as a target of miR-527. Overall, the present study suggested that hsa_circ_0001394 may function as a sponge to promote HCC progression by regulating the miR-527/UBE2A pathway. Thus, hsa_circ_0001394 may become a promising biomarker and potential therapeutic target in HCC treatment.

Identification and Validation of 7-lncRNA Signature of Epigenetic Disorders by Comprehensive Epigenetic Analysis

The survival rate of patients with lung adenocarcinoma (LUAD) is low. This study analyzed the correlation between the expression of long noncoding RNA (lncRNA) and epigenetic alterations along with the investigation of the prognostic value of these outcomes for LUAD. Differentially expressed lncRNAs were identified based on multiomic data and positively related genes using DESeq2 in R, differentially histone-modifying genes specific to LUAD based on histone modification data, gene enhancers from information collected from the FANTOM5 (Function Annotation Of The Mammalian Genome-5) (fantom.gsc.riken.jp/5) human enhancer database, gene promoters using the ChIPseeker and the human lincRNAs Transcripts database in R, and differentially methylated regions (DMRs) using Bumphunter in R. Overall survival was estimated by Kaplan-Meier, comparisons were performed among groups using log-rank tests to derive differences between sample subclasses, and epigenetic lncRNAs (epi-lncRNAs) potentially relevant to LUAD prognosis were identified. A total of seven dysregulated epi-lncRNAs in LUAD were identified by comparing histone modifications and alterations in histone methylation regions on lncRNA promoter and enhancer elements, including H3K4me2, H3K27me3, H3K4me1, H3K9me3, H4K20me1, H3K9ac, H3K79me2, H3K27ac, H3K4me3, and H3K36me3. Furthermore, 69 LUAD-specific dysregulated epi-lncRNAs were identified. Moreover, lncRNAs-based prognostic analysis of LUAD samples was performed and explored that seven of these lncRNAs, including A2M-AS1, AL161431.1, DDX11-AS1, FAM83A-AS1, MHENCR, MNX1-AS1, and NKILA (7-EpiLncRNA), showed the potential to serve as markers for LUAD prognosis. Additionally, patients having a high 7-EpiLncRNA score showed a generally more unfavorable prognosis compared with those which scored lower. Seven lncRNAs were identified as markers of prognosis in patients with LUAD. The outcomes of this research will help us understand epigenetically aberrant regulation of lncRNA expression in LUAD in a better way and have implications for research advances in the regulatory role of lncRNAs in LUAD.

Novel long non‐coding RNA CYB561‐5 promotes aerobic glycolysis and tumorigenesis by interacting with basigin in non‐small cell lung cancer

Abnormally expressed long non‐coding RNAs (lncRNAs) have been recognized as potential diagnostic biomarkers or therapeutic targets in non‐small cell lung cancer (NSCLC). The role of the novel lnc‐CYB561‐5 in NSCLC and its specific biological activity remain unknown. In this study, lncRNAs highly expressed in NSCLC tissue samples compared with paired adjacent normal tissue samples and atypical adenomatous hyperplasia were identified by RNA‐seq analysis. Lnc‐CYB561‐5 is highly expressed in human NSCLC and is associated with a poor prognosis in lung adenocarcinoma. In vivo, downregulation of lnc‐CYB561‐5 significantly decreases tumour growth and metastasis. In vitro, lnc‐CYB561‐5 knockdown treatment inhibits cell migration, invasion and proliferation ability, as well as glycolysis rates. In addition, RNA pulldown and RNA immunoprecipitation (RIP) assays show that basigin (Bsg) protein interacts with lnc‐CYB561‐5. Overall, this study demonstrates that lnc‐CYB561‐5 is an oncogene in NSCLC, which is involved in the regulation of cell proliferation and metastasis. Lnc‐CYB561‐5 interacts with Bsg to promote the expression of Hk2 and Pfk1 and further lead to metabolic reprogramming of NSCLC cells.

H3K27ac-activated EGFR-AS1 promotes cell growth in cervical cancer through ACTN4-mediated WNT pathway

Background

Recently, extensive studies unveiled that lncRNAs exert critical function in the development and progression of cervical cancer (CC). EGFR-AS1 is a novel lncRNA which has not been well-explored in CC.

Aims

Our study aimed to research the function and molecular mechanism of EGFR-AS1 in CC cells. qRT-PCR analysis was performed to detect gene expression. Colony formation, EdU, flow cytometry, TUNEL, western blot and transwell assays were performed to assess the effect of EGFR-AS1 on CC cell growth. The regulatory mechanism of EGFR-AS1 was dug out through mechanism experiments.

Results

EGFR-AS1 was notably overexpressed in CC cell lines. Loss-of-functional experiments revealed that EGFR-AS1 promoted CC cell proliferation, migration and invasion, and suppressed cell apoptosis. Mechanistically, up-regulation of EGFR-AS1 was attributed to the activation of H3K27 acetylation (H3K27ac). Further, EGFR-AS1 was revealed to function as miR-2355-5p sponge. Additionally, miR-2355-5p was down-regulated in CC cells and ACTN4 was identified as a target gene of miR-2355-5p. Ultimately, overexpressed ACTN4 could reserve the suppressive role of EGFR-AS1 silencing in CC cell growth. Last but not least, EGFR-AS1 facilitated CC cell growth via ACTN4-mediated WNT pathway.

Conclusions

H3K27ac-activated EGFR-AS1 sponged miR-2355-5p and promoted CC cell growth through ACTN4-mediated WNT pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13062-021-00315-5.

LINC02381 aggravates breast cancer through the miR-1271-5p/FN1 axis to activate PI3K/AKT pathway

Emerging investigations have demonstrated that lncRNAs are key crucial modulators in cancer. In this study, we investigated the role of LINC02381 in breast cancer (BC). Reverse transcriptase quantitative polymerase chain reaction measured the LINC02381 level in BC tissues and cells. Colony formation, EdU staining, wound healing and Transwell experiments examined the impact of LINC02381 depletion on BC cell phenotypes. Relationship among miR-1271-5p, LINC02381, and FN1 was tested through applying RIP, luciferase reporter, and RNA pull-down assays. We found that LINC02381 expression was elevated in BC. Functionally, LINC02381 knockdown hampered BC cell proliferation, migration, and invasion. LINC02381 overexpression accelerated tumor formation in vivo. Mechanistically, LINC02381 acted as a ceRNA to increase FN1 via decoying miR-1271-5p. Additionally, LINC02381 activated PI3K/AKT pathway by upregulating FN1. Rescue assays indicated that FN1 upregulation or PI3K/AKT activation rescued the LINC02381 knockdown-mediated inhibition on malignant phenotypes of BC cells. Overall, LINC02381 exerts carcinogenic effects in BC by the miR-1271-5p/FN1 axis to activate PI3K/AKT pathway.

Clinical significance of long noncoding RNA MNX1-AS1 in human cancers: a meta-analysis of cohort studies and bioinformatics analysis based on TCGA datasets

MNX1-AS1 expression has been proposed to be abnormally upregulated in multiple human malignancies and be linked with the survival outcome of patients. However, relevant conclusions were yielded based on the limited samples. Therefore, we herein implemented a meta-analysis of the published cohort studies to further decipher the relationship of MNX1-AS1 level to prognosis and clinicopathological features in various cancers. Additionally, using The Cancer Genome Atlas (TCGA) datasets we carried out a bioinformatics analysis to make a further evaluation on the prognostic value of MNX1-AS1 expression. The results of meta-analysis indicated elevated MNX1-AS1 level closely correlated with poorer overall survival (OS) (HR = 1.97, 95% CI, 1.73-2.24; P < 0.00001), and disease-free survival (DFS) (HR = 2.24, 95% CI, 1.48-3.38; P = 0.0001) in cancers, which was confirmed by the bioinformatics analysis. Besides, it was observed the upregulated MNX1-AS1 level was significantly related to invasion depth, disease stage, tumor metastasis, and differentiation. Collectively, high MNX1-AS1 level correlated with poor survival outcome and aggressive clinicopathological characteristics in various cancers, suggesting that MNX1-AS1 may be applied as a prognostic marker and even a therapeutic target. Nevertheless, more high-quality studies designed with a large sample size should be conducted to further determine the clinical role of MNX1-AS1 in specific cancer types.

LncRNA MNX1-AS1 promotes ovarian cancer process via targeting the miR-744-5p/SOX12 axis

Purpose

Ovarian cancer (OC) is the most common malignancy in women with high mortality. Increasing studies have revealed that long non-coding RNA (lncRNA) MNX1-AS1 has a promoting effect on various cancers. However, the mechanisms of MNX1-AS1 in OC are still unclear. Therefore, this study focused on exploring the mechanisms of MNX1-AS1 in OC.

Materials and methods

The expression of SOX12 at the protein level was detected by western blot. Cell proliferation was detected by CCK8 assay and colony formation assay. Cell cycle and cell apoptosis were detected by flow cytometry. Wound-healing assay, transwell assay and western blot were used to detect the ability of cell migration and invasion. The target binding was confirmed through the luciferase reporter assay.

Results

The expression of MNX1-AS1 was increased in OC tumor tissues and cells. Elevated MNX1-AS1 expression is associated with advanced stage and lower overall survival rate. Knockdown of MNX1-AS1 inhibited cell proliferation, migration and invasion, blocked cell cycle, and promoted cell apoptosis in SKOV-3 and OVCAR-3 cells. MNX1-AS1 was competitively binding with miR-744-5p, and its downstream target gene was SOX12. miR-544-5p expression was decreased, while SOX12 expression was increased in OC tumor tissues and cells. Overexpression of miR-744-5p inhibited cell proliferation, migration, invasion and promoted cell apoptosis in SKOV-3 and OVCAR-3 cells.

Conclusion

MNX1-AS1 promoted the development of OC through miR-744-5p/SOX12 axis. This study revealed a novel mechanism of MNX1-AS1 in OC, which may provide a new treatment or scanning target for OC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00910-0.

Genomic Instability Promotes the Progression of Clear Cell Renal Cell Carcinoma Through Influencing the Immune Microenvironment

Background: Long non-coding RNAs (lncRNAs) are now under discussion as novel promising biomarkers for clear cell renal cell carcinoma (ccRCC). However, the role of genomic instability-associated lncRNA signatures in tumors has not been thoroughly uncovered. The purpose of our study is to probe the role of genomic instability-derived lncRNA signature (GILncSig) and to further investigate the mechanism of genomic instability-mediated ccRCC progression. Methods: The transcriptome data and somatic mutation profiles of ccRCC as well as clinical characteristics used in this study were obtained from The Cancer Genome Atlas database and Gene Expression Omnibus database. Lasso regression analysis was performed to construct the GILncSig. Gene set enrichment analysis (GSEA) was performed to elucidate the biological functions and relative pathways. CIBERSORT and EPIC algorithm were applied to calculate the proportion of immune cells in ccRCC. ESTIMATE algorithm was utilized to compute the immune microenvironment scores. Results: In total, 148 novel genomic instability-derived lncRNAs in ccRCC were identified. Immediately, on the basis of univariate cox analysis and lasso analysis, a GILncSig was appraised, through which the patients were allocated into High-Risk and Low-Risk groups with significantly different characteristics and prognoses. In addition, we confirmed that the somatic mutation count, tumor mutation burden, and the expression of UBQLN4, which were ascertainably associated with genomic instability, were significantly correlated with the GILncSig, indicating its reliability as a measurement of the genomic instability. Furthermore, the efficiency of GILncSig in prognostic aspects was better than the single mutation gene in ccRCC. In addition, MNX1-AS1 was defined to be a potential biomarker characterized by strong correlation with clinical features. Moreover, GSEA results indicated that the IL6/JAK/STAT3/SIGNALING pathway could be considered as a potential mechanism of genomic instability to influence tumor progression. Besides, the immune microenvironment showed significant differences between the GS-like group and the GU-like group, which was specifically manifested as high expression of CTLA4, GITR, TNFSF14, and regulatory T cells (Tregs) as well as low expression of endothelial cells (ECs) in the GU-like group. Finally, the prognostic value and clinical relevance of GILncSig were verified in GEO datasets and other urinary tumors in TCGA dataset. Conclusion: In conclusion, our study provided a new perspective for the role of lncRNAs in genomic instability and revealed that genomic instability may mediate tumor progression by affecting immunity. Besides, MNX1-AS1 played critical roles in promoting the progression of ccRCC, which may be a potential therapeutic target. What is more, the immune atlas of genomic instability was characterized by high expression of CTLA4, GITR, TNFSF14, and Tregs, and low expression of ECs.

LINC01234 aggravates cell growth and migration of triple-negative breast cancer by activating the Wnt pathway

Triple-negative breast cancer (TNBC) is a common cancer with increasing incidence and mortality in female. Increasing studies have revealed that long noncoding RNAs (lncRNAs) are novel molecules regulating tumors. Long intergenic non-protein coding RNA 1234 (LINC01234) has been demonstrated to function as an oncogene in several tumors. However, the role of LINC01234 in TNBC remains unelucidated. Herein, RT-qPCR showed that LINC01234 expression was upregulated in both TNBC tissues and cell lines. Functionally, knockdown of LINC01234 suppressed proliferation, migration, invasion, epithelial-mesenchymal transition (EMT) process, and promoted apoptosis in TNBC cells. Xenograft mouse models revealed that LINC01234 downregulation inhibited TNBC tumor growth in vivo. Furthermore, LINC01234 was transcriptionally elevated by Sp1 transcription factor (SP1) in TNBC cells. Mechanistically, LINC01234 interacted with miR-525-5p and miR-525-5p targeted MEIS2. Rescue assays manifested that MEIS2 overexpression rescued the cellular processes inhibited by silenced LINC01234. Moreover, we validated that LINC01234 regulated the activation of the Wnt pathway through modulating MEIS2 in TNBC cells. In conclusion, LINC01234 aggravated TNBC cell growth, migration, invasion and EMT by modulating the miR-525-5p/MEIS2 axis and activating the Wnt/β-catenin signaling pathway.

LINC01342 silencing upregulates microRNA-508-5p to inhibit progression of lung cancer by reducing cysteine-rich secretory protein 3

Long noncoding RNAs (lncRNAs) are critical players during cancer progression. Nevertheless, the effect of most lncRNAs in lung cancer (LC) remains unclear. We aimed to explore the role of LINC01342 in LC development through the microRNA-508-5p (miR-508-5p)/cysteine-rich secretory protein 3 (CRISP3) axis. LINC01342, miR-508-5p, and CRISP3 expression in clinical samples and cell lines were determined, and their correlations in LC were analyzed. The prognostic role of LINC01342 in LC patients was evaluated. LC cells were screened and, respectively, transfected to alter the expression of LINC01342, miR-508-5p, and CRISP3. Then, proliferation, migration, invasion, and apoptosis of transfected LC cells were determined, and the in vivo tumor growth was observed as well. Binding relationships between LINC01342 and miR-508-5p, and between miR-508-5p and CRISP3 were identified. LINC01342 and CRISP3 were upregulated and miR-508-5p was downregulated in LC tissues and cells. High LINC01342 expression indicated a poor prognosis of LC patients. The LINC01342/CRISP3 silencing or miR-508-5p elevation inhibited proliferation, migration, and invasion of LC cells and promoted LC cell apoptosis, and also suppressed the in vivo tumor growth. LINC01342 bound to miR-508-5p and miR-508-5p targeted CRISP3. LINC01342 plays a prognostic role in LC and LINC01342 silencing upregulates miR-508-5p to inhibit the progression of LC by reducing CRISP3.

circ_C20orf11 enhances DDP resistance by inhibiting miR-527/YWHAZ through the promotion of extracellular vesicle-mediated macrophage M2 polarization in ovarian cancer

Ovarian cancer is a fatal gynecologic tumor, and conventional treatment is mainly limited by chemoresistance. The mechanism contributing to chemoresistance in ovarian cancer has yet to be established. This study aimed to investigate the specific role of circ_C20orf11 in regulating chemoresistance to cisplatin (DDP)in ovarian cancer. We first established two DDP-resistant ovarian cancer cell lines. Then, we identified the effect of circ_C20orf11 on specific cellular characteristics (proliferation, apoptosis, DDP resistance) via a series of experiments. The binding sites between circ_C20orf11 and miR-527 and between miR-527 and YWHAZ were predicted using a bioinformatics tool and confirmed with a dual-luciferase reporter assay. Furthermore, extracellular vesicles (EVs) derived from DDP-resistant cell lines were identified, and the effect of EVs on macrophage polarization was examined. circ_C20orf11 was upregulated in ovarian cancer. Increased circ_C20orf11 expression enhanced DDP resistance and cell proliferation and reduced cell apoptosis in DDP-resistant cell lines after DDP treatment by sponging miR-527 and promoting YWHAZ expression. In addition, we found that DDP-resistant cell-derived EVs can induce macrophage M2 polarization, whereas silencing of circ_C20orf11 inhibited EV-induced macrophage M2 polarization. Consistent with these results, silencing of circ_C20orf11 enhanced sensitivity to DDP in vivo. Importantly, we proved that circ_C20orf11 expression was upregulated in EVs extracted from the serum of DDP-resistant patients. Our study demonstrated that silencing circ_C20orf11 sensitizes ovarian cancer to DDP by promoting miR-527/YWHAZ signaling and EV-mediated macrophage M2 polarization.

The Regulatory Network and Potential Role of LINC00973-miRNA-mRNA ceRNA in the Progression of Non-Small-Cell Lung Cancer

Background

The occurrence and development of cancer could be promoted by abnormally competing endogenous RNAs (ceRNA) network. This article aims to determine the prognostic biomarker of ceRNA for non-small-cell lung cancer (NSCLC) prognosis.

Methods

The expression and clinical significance of LINC00973 in NSCLC tissues were analyzed via the The Cancer Genome Atlas (TCGA), Gene Expression Profiling Interactive Analysis (GEPIA), lnCAR, and clinical samples in Taihe Hospital. The biological functions and signaling pathways involved in target genes of ceRNA network were analyzed via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Survival analysis, univariate and multivariate Cox regression analysis were used for prognostic-related mRNA.

Results

Expression of LINC00973 was increased in NSCLC tissues. High expression of LINC00973 was associated with poor prognosis of NSCLC patients. There were 15 miRNA and 238 differential mRNA in the INC00973-miRNA-mRNA ceRNA network, involving cell migration, endothelial cell proliferation, tumor growth factor (TGF)-β, cellular senescence, phosphatidylinositol 3-hydroxy kinase (PI3K)-Akt, Hippo, Rap1, mitogen-activated protein kinase (MAPK), cell cycle signaling pathway, etc. The expression levels of RTKN2, NFIX, PTX3, BMP2 and LOXL2 were independent risk factors for the poor prognosis of NSCLC patients.

Conclusions

LINC00973-miRNA-mRNA ceRNA network might be the basis for determining pivotal post-translational regulatory mechanisms in the progression of NSCLC. BMP2, LOXL2, NFIX, PTX3 and RTKN2 might be valuable prognostic markers and potential therapeutic targets.

Long non-coding RNA LINC01116 is activated by EGR1 and facilitates lung adenocarcinoma oncogenicity via targeting miR-744-5p/CDCA4 axis

Background

Lung adenocarcinoma (LAD) is one of the most frequently diagnosed pathological categories of human lung cancer. Nevertheless, the link between long non-coding RNA (lncRNA) LINC01116 and LAD remains poorly investigated.

Methods

QRT-PCR and western blot were applied for quantifying the expression of RNAs and proteins. Both functional experiments assays in vitro and xenografts model in vivo were implemented for analyzing LINC01116 function in LAD while molecular relationship among RNAs was investigated via mechanism experiments.

Results

LINC01116 was expressed at an abnormally high level in LAD, which was induced by transcription activator EGR1. LINC01116 depletion restrained proliferation, migration and invasion, yet facilitated apoptosis of LAD cells. MiR-744-5p could bind to LINC01116. MiR-744-5p inhibitor reversed the inhibitory effects of silencing LINC01116 on LAD malignant behaviors. In addition, cell division cycle-associated protein 4 (CDCA4) shared binding sites with miR-744-5p. Silencing LINC01116 elicited decline in CDCA4 mRNA and protein levels. Moreover, CDCA4 up-regulation could counteract the biological effects of LINC01116 knockdown on LAD cells.

Conclusion

Our data revealed that LINC01116 promoted malignant behaviors of LAD cells by targeting miR-744-5p/CDCA4 axis, implying the theoretical potential of LINC01116 as a novel target for LAD treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01994-w.

A novel autophagy-related lncRNA survival model for lung adenocarcinoma

Long non‐coding RNA (lncRNA) is an important regulatory factor in the development of lung adenocarcinoma, which is related to the control of autophagy. LncRNA can also be used as a biomarker of prognosis in patients with lung adenocarcinoma. Therefore, it is important to determine the prognostic value of autophagy‐related lncRNA in lung adenocarcinoma. In this study, autophagy‐related mRNAs‐lncRNAs were screened from lung adenocarcinoma and a co‐expression network of autophagy‐related mRNAs‐lncRNAs was constructed by using The Cancer Genome Atlas (TCGA). The univariate and multivariate Cox proportional hazard analyses were used to evaluate the prognostic value of the autophagy‐related lncRNAs and finally obtained a survival model composed of 11 autophagy‐related lncRNAs. Through Kaplan‐Meier analysis, univariate and multivariate Cox regression analysis and time‐dependent receiver operating characteristic (ROC) curve analysis, it was further verified that the survival model was a new independent prognostic factor for patients with lung adenocarcinoma. In addition, based on the survival model, gene set enrichment analysis (GSEA) was used to illustrate the function of genes in low‐risk and high‐risk groups. These 11 lncRNAs were GAS6‐AS1, AC106047.1, AC010980.2, AL034397.3, NKILA, AL606489.1, HLA‐DQB1‐AS1, LINC01116, LINC01806, FAM83A‐AS1 and AC090559.1. The hazard ratio (HR) of the risk score was 1.256 (1.196‐1.320) (P < .001) in univariate Cox regression analysis and 1.215 (1.149‐1.286) (P < .001) in multivariate Cox regression analysis. And the AUC value of the risk score was 0.809. The 11 autophagy‐related lncRNA survival models had important predictive value for the prognosis of lung adenocarcinoma and may become clinical autophagy‐related therapeutic targets.

Long noncoding RNA-dependent methylation of nonhistone proteins

In the last decade, an intriguing new paradigm of regulation has emerged in which some transcripts longer than 200 nucleotides and no coding potential, long noncoding RNA (lncRNAs), exhibit the capability to control posttranslational modifications of nonhistone proteins in both invertebrates and vertebrates. The extent of such a regulation is still largely unknown. We performed a systematic review to identify and evaluate the potential impact of lncRNA-dependent methylation of nonhistone proteins. Collectively, these lncRNAs primarily act as scaffolds upon which methyltransferases (MTases) and targets are brought in proximity. In this manner, the N-MTase activity of EZH2, protein arginine-MTase 1/4/5, and SMYD2 is exploited to modulate the stability or the compartmentalization of several nonhistone proteins with roles in cell signaling, gene expression, and RNA processing. Moreover, these lncRNAs can indirectly affect the methylation of nonhistone proteins by transcriptional or posttranscriptional regulation of MTases. Strikingly, the lncRNAs/MTases/nonhistone proteins networking seem to be relevant to carcinogenesis and neurological disorders. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.

LncRNA MNX1-AS1 Contributes to Laryngeal Squamous Cell Carcinoma Growth and Migration by Regulating mir-744-5p/bcl9/β-Catenin Axis

Increasing evidence has indicated that long noncoding RNAs (lncRNAs) are involved in the progression of laryngeal squamous cell carcinoma (LSCC). Here, we aimed to disclose the role of MNX1-AS1 in LSCC progression, and explore whether MNX1-AS1 participates in LSCC progression via targeting miR-744-5p to active BCL9/β-catenin signaling. Sixty-five human LSCC tissues and the paracancerous normal tissues were recruited to determine the levels of MNX1-AS1, miR-744-5p and BCL9 using qRT-PCR. The interaction of miR-744-5p and MNX1-AS1/BCL9 was determined by using the RNA immunoprecipitation (RIP) assay and/or luciferase gene reporter assay. Cell viability, in vivo tumor formation, invasion and migration abilities were detected by MTT, Xenograft models and Transwell assays. MNX1-AS1 level was increased significantly in human LSCC tissues as compared with the normal tissues, which showed a positive correlation with BCL9 level while a negative correlation with miR-744-5p level. High level of MNX1-AS1 predicted a poor prognosis and an advanced clinical process in LSCC patients. miR-744-5p targeted upregulation weakened the luciferase activity of MNX1-AS1 and /BCL9, and downregulated their expression levels-wt, while showed no effect when the binding sites were mutated. Knockdown of MNX1-AS1 markedly weakened cell viability, migration, and invasion abilities, while BCL9 overexpression abolished these tendencies. In addition, MNX1-AS1 downregulation induced decreases in tumor volumes and weights in vivo, accompanied by reductions in BCL9, Ki-67 and β-catenin expression and an increase in miR-744-5p expression. Collectively, this study reveals that MNX1-AS1 contributes to cell growth and migration by regulating miR-744-5p/BCL9/β-catenin axis in LSCC.

Let-7b-3p inhibits tumor growth and metastasis by targeting the BRF2-mediated MAPK/ERK pathway in human lung adenocarcinoma

Background

Lung cancer is a malignant tumor with the highest morbidity and mortality rates worldwide, of which lung adenocarcinoma (LUAD) is the most common subtype. Overall, current treatments of LUAD are not satisfactory; therefore, novel targets need to be explored. Let-7b-3p is an important member of the let-7 family of microRNAs (miRNAs), and has not been studied separately in LUAD. This study aimed to investigate the role and molecular mechanism of let-7b-3p in LUAD.

Methods

Herein, let-7b-3p expression was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and fluorescence in situ hybridization (FISH) assays. MTT, colony formation assay, flow cytometry analysis, wound-healing, Transwell and in vivo experiments were conducted to assess let-7b-3p’s function in LUAD. The downstream target TFIIB-related factor 2 (BRF2) was predicted using bioinformatics analyses and confirmed by dual-luciferase reporter assay and rescue experiments. Additionally, BRF2 was found to affect the MAPK/ERK pathway through transcriptome sequencing analysis and western blot (WB) assay.

Results

Let-7b-3p is downregulated in LUAD cells and tissue samples and low let-7b-3p expression is correlated with a poor prognosis in LUAD patients. Let-7b-3p suppresses the proliferation and metastasis of LUAD cells both in vivo and in vitro by directly targeting the BRF2-mediated MAPK/ERK pathway.

Conclusions

Let-7b-3p inhibits the development of LUAD and is an ideal novel therapeutic target for the treatment of LUAD.

LncRNA MNX1-AS1 drives aggressive laryngeal squamous cell carcinoma progression and serves as a ceRNA to target FoxM1 by sponging microRNA-370

Long non-coding RNA (LncRNA) MNX1 antisense RNA 1(MNX1-AS1) is associated with the pathology of numerous cancers. But, the role and underlying pathways of MNX1-AS1 in the regulation of laryngeal squamous cell carcinoma (LSCC) is not known. We demonstrated remarkably elevated levels of MNX1-AS1 in the LSCC tissues, which was correlated with poor disease prognosis. Moreover, MNX1-AS1-silencing strongly suppressed LSCC cell proliferation, migration, and invasion. We also demonstrated that MNX1-AS1 sequesters that activity of miR-370, thereby releasing Forkhead Box ml (FoxM1) from the inhibitory actions of MNX1-AS1. Furthermore, the positive correlation of MNX1-AS1 and FoxM1 as well as the converse correlation between miR-370 and MNX1-AS1 (or FoxM1) were revealed in LSCC tissues using experiments. Based on rescue assays, FoxM1 overexpression or miR-370 downregulation partially recovered the inhibitory effect of MNX1-AS1 silencing on LSCC cells. Moreover, knockdown of MNX1-AS1 retarded tumor growth in nude mice model. In summary, these findings verified that MNX1-AS1 modulated LSCC progression by competitively binding with miR-370 to regulate FoxM1.

Long Non-coding RNA LINC01969 Promotes Ovarian Cancer by Regulating the miR-144-5p/LARP1 Axis as a Competing Endogenous RNA

Accumulating evidence has shown that long non-coding RNAs (lncRNAs) can be used as biological markers and treatment targets in cancer and play various roles in cancer-related biological processes. However, the lncRNA expression profiles and their roles and action mechanisms in ovarian cancer (OC) are largely unknown. Here, we assessed the lncRNA expression profiles in OC tissues from The Cancer Genome Atlas (TCGA) database, and one upregulated lncRNA, LINC01969, was selected for further study. LINC01969 expression levels in 41 patients were verified using quantitative real-time polymerase chain reaction (qRT-PCR). The in vitro effects of LINC01969 on OC cell migration, invasion, and proliferation were determined by the CCK-8, ethynyl-2-deoxyuridine (EdU), wound healing, and Transwell assays. Epithelial–mesenchymal transition (EMT) was evaluated using qRT-PCR and Western blotting. The molecular mechanisms of LINC01969 in OC were assessed through bioinformatics analysis, RNA-binding protein immunoprecipitation (RIP), dual luciferase reporter gene assays, and a rescue experiment. Finally, in vivo experiments were conducted to evaluate the functions of LINC01969. The results of the current study showed that LINC01969 was dramatically upregulated in OC, and patients with lower LINC01969 expression levels tended to have better overall survival. Further experiments demonstrated that LINC01969 promoted the migration, invasion, and proliferation of OC cells in vitro and sped up tumor growth in vivo. Additionally, LINC01969, which primarily exists in the cytoplasm, boosted LARP1 expression by sponging miR-144-5p and promoted the malignant phenotypes of OC cells. In conclusion, the LINC01969/miR-144-5p/LARP1 axis is a newly identified regulatory signaling pathway involved in OC progression.

circRNA_0005529 facilitates growth and metastasis of gastric cancer via regulating miR-527/Sp1 axis

BACKGROUND

Circular RNAs (circRNAs) are endogenous non-coding RNAs, which are associated with various biological processes, including microRNA (miRNA) interaction, protein binding and regulatory splicing. circRNA_0005529 (circ_0005529) is derived from vacuolar protein sorting 33 homologue B (VPS33B), and its biological role in gastric cancer (GC) has not been examined. In this study, the expression and location of circ_0005529 and microRNA-527 (miR-527) were determined by qRT-PCR and fluorescence in situ hybridization (FISH). Cell proliferation and cell migration were determined by MTT, EdU incorporation, colony formation, wound scratch and transwell assays. In addition, immunohistochemistry and western blotting were performed to determine the expressions of specificity protein 1 (Sp1), PCNA, c-myc, E-cadherin and N-cadherin. Western blotting and luciferase reporter assay were performed to study the interaction between circ_0005529 and miR-527 or miR-527 and Sp1. The functional effects of circ_0005529 on GC through regulating Sp1 were further evaluated using xenograft and metastatic mouse models in vivo.

RESULTS

Our results showed that circ_0005529 was upregulated in GC tissues and cells, and had promoting effects on cell proliferation and cell migration. Mechanism analysis suggested that circ_0005529 could bind to microRNA-527 (miR-527) and reduce its expression. The interaction between miR-527 and Sp1 in GC was systematically studied. In addition, the results indicated that Sp1 upregulation could rescue the effects on cell proliferation and migration caused by circ_0005529. Moreover, the inhibitory effects of circ_0005529 downregulation on GC growth and metastasis were evaluated in mouse models. These findings suggested that the axis of circ_0005529/miR-527/Sp1 may serve as a promising treatment target for GC diagnosis and treatment.

CONCLUSIONS

These findings suggested that the signal axis of circ_0005529/miR-527/Sp1 may has the potential to be explored as a novel therapeutic target for GC diagnosis and treatment. Mechanism diagram: During GC development, overexpressed circ_0005529 sponged miR-527 and then upregulated the expression of Sp1. Subsequently, epithelial-mesenchymal transition (EMT), cell proliferation and cell migration were promoted, which ultimately facilitated the tumor metastasis.

The ceRNA network of lncRNA and miRNA in lung cancer

Since lung cancer is a major causative for cancer-related deaths, the investigations for discovering biomarkers to diagnose at an early stage and to apply therapeutic strategies have been continuously conducted. Recently, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are being exponentially studied as promising biomarkers of lung cancer. Moreover, supportive evidence provides the competing endogenous RNA (ceRNA) network between lncRNAs and miRNAs participating in lung tumorigenesis. This review introduced the oncogenic or tumor-suppressive roles of lncRNAs and miRNAs in lung cancer cells and summarized the involvement of the lncRNA/miRNA ceRNA networks in carcinogenesis and therapeutic resistance of lung cancer.

Amplification of 8p11.23 in cancers and the role of amplicon genes

Copy number alterations are widespread in cancer genomes and are part of the genomic instability underlying the pathogenesis of neoplastic diseases. Recurrent copy number alterations of specific chromosomal loci may result in gains of oncogenes or losses of tumor suppressor genes and become entrenched in the genomic framework of certain types of cancers. The locus at chromosome 8p11.23 presents recurrent amplifications most commonly in squamous lung carcinomas, breast cancers, squamous esophageal carcinomas, and urothelial carcinomas. Amplification is rare in other cancers. The amplified segment involves several described oncogenes that may promote cancer cell survival and proliferation, as well as less well characterized genes that could also contribute to neoplastic processes. Genes proposed to be "drivers" in 8p11.23 amplifications include ZNF703, FGFR1 and PLPP5. Additional genes in the locus that could be functionally important in neoplastic networks include co-chaperone BAG4, lysine methyltransferase NSD3, ASH2L, a member of another methyltransferase complex, MLL and the mRNA processing and translation regulators LSM1 and EIF4EBP1. In this paper, genes located in the amplified segment of 8p11.23 will be examined for their role in cancer and data arguing for their importance for cancers with the amplification will be presented.

LncRNA SLCO4A1-AS1 promotes colorectal cancer cell proliferation by enhancing autophagy via miR-508-3p/PARD3 axis

Aberrant expressions of various long non-coding RNAs (lncRNAs) have been involved in the progression and pathogenesis of various carcinomas. However, the expression and biological function of SLCO4A1-AS1 in colorectal cancer (CRC) remain poorly understood. Gain- and loss-of-function assays were applied to determine the roles of SLCO4A1-AS1 in autophagy and CRC progression. qRT-PCR and in situ hybridization (ISH) results showed that SLCO4A1-AS1 was positively associated with PARD3 expression in CRC tissues. In vitro and in vivo studies revealed that SLCO4A1-AS1 knockdown repressed cytoprotective autophagy as assayed by transmission electron microscopy (TEM), and inhibited cell proliferation by directly targeting partition-defective 3 (PARD3). Mechanistically, SLCO4A1-AS1 acted as a sponge of miR-508-3p, leading to upregulation of PARD3 and promotion of CRC cell proliferation. The current study demonstrates that the SLCO4A1-AS1/miR-508-3p/PARD3/autophagy pathway play a critical role in CRC cell proliferation, and might provide novel targets for developing therapeutic strategies for CRC.

Silencing of BRF2 inhibits the growth and metastasis of lung cancer cells

Transcription factor II B (TFIIB)‑related factor 2 (BRF2) is involved in the development of cancer, but its role in lung cancer is underreported. The present study aimed to explore the role of BRF2 in the regulation of lung cancer cells. Immunofluorescence staining and immunohistochemistry were performed to detect BRF2 protein expression in human lung cancer cells and tissues. Following cell transfection with small interfering RNA for silencing BRF2, the cell proliferation was examined by Cell Counting Kit‑8 and MTT assays. Cell apoptosis, migration and invasion were determined by flow cytometry, wound‑healing and Transwell assay. The expression levels of Akt, phosphorylated (p)‑Akt, Bax, E‑cadherin, Bcl‑2, N‑cadherin, Snail and epidermal growth factor receptor (EGFR) in human lung cancer A549 cells were detected by western blotting. The results demonstrated that BRF2 expression was increased in human lung cancer cells and tissues, and that silencing of BRF2 promoted cell apoptosis but inhibited cell proliferation and migration. The protein expression levels of Akt, E‑cadherin, p‑Akt, Bcl‑2, N‑cadherin, Snail and EGFR in A549 cells were inhibited by silencing of BRF2, while expression levels of Bax and E‑cadherin were increased by silencing BRF2. In conclusion, BRF2 demonstrates high expression in lung cancer and silencing of BRF2 inhibits the growth and metastasis of lung cancer cells. The current findings provide a novel approach for the treatment of lung cancer.

CircZNF609 enhances hepatocellular carcinoma cell proliferation, metastasis, and stemness by activating the Hedgehog pathway through the regulation of miR-15a-5p/15b-5p and GLI2 expressions

Emerging evidence has revealed that aberrantly expressed circular RNAs (circRNAs) play vital roles in tumorigenesis and progression of diverse human malignancies. Although an existing literature has elucidated the regulatory role of circZNF609 in breast cancer, the crucial function that circZNF609 exerted on hepatocellular carcinoma (HCC) remains unclear. Herein, we determined to explore the molecular mechanism of circZNF609 in HCC. In this study, circZNF609 was conspicuously overexpressed and featured with loop structure in HCC. Functional tests revealed that decreased expression of circZNF609 suppressed cell proliferation, metastasis and stemness, whereas induced cell apoptosis in HCC. Subsequent molecular mechanism assays indicated that circZNF609 contributed to HCC progression through activation of Hedgehog pathway. Moreover, circZNF609 was found to be negatively correlated with miR-15a-5p/15b-5p but positively correlated with GLI2. Moreover, there was a negative correlation between miR-15a-5p/15b-5p and GLI2. Rescue experiments testified that GLI2 overexpression could recover circZNF609 depletion-mediated function on HCC development while miR-15a-5p/15b-5p inhibition could partially rescue circZNF609 silencing-mediated effect on HCC progression. Final experiments in vivo further elucidated the suppressive function of circZNF609 knockdown on the tumorigenesis of HCC. Briefly, circZNF609 enhances HCC cell proliferation, metastasis, and stemness by activating the Hedgehog pathway through the regulation of miR-15a-5p/15b-5p and GLI2 expressions.

LBX2-AS1/miR-219a-2-3p/FUS/LBX2 positive feedback loop contributes to the proliferation of gastric cancer

BACKGROUND

Long non-coding RNAs (lncRNAs) are increasingly investigated in numerous carcinomas containing gastric cancer (GC). The aim of our research is to inquire about the expression profile and role of LBX2-AS1 in GC.

METHODS

The expressions of LBX2-AS1, miR-219a-2-3p, FUS and LBX2 were measured by qRT-PCR. Western blot evaluated FUS and LBX2 protein levels. Cell proliferation and apoptosis were, respectively, evaluated by CCK-8, colony formation, EdU, flow cytometry and TUNEL assays. FISH and subcellular fractionation assays examined the position of LBX2-AS1. The binding between genes were certified by RIP, RNA pull-down, ChIP and luciferase reporter assays. Pearson correlation analysis analyzed the association of genes. Kaplan-Meier method detected the relationship of LBX2-AS1 expression with overall survival.

RESULTS

The up-regulation of LBX2-AS1 in GC tissues and cells was verified. Function assays proved that LBX2-AS1 down-regulation restricted the proliferation ability. Then, we unveiled the LBX2-AS1/miR-219a-2-3p/FUS axis. Additionally, LBX2-AS1 positively regulated LBX2 mRNA stability via FUS. LBX2 transcriptionally modulated LBX2-AS1. In the end, rescue and in vivo experiments validated the whole regulatory mechanism.

CONCLUSION

LBX2-AS1/miR-219a-2-3p/FUS/LBX2 positive feedback loop mainly affected the proliferation and apoptosis abilities of GC cells, offering novel therapeutic targets for the treatment of patients with GC.

Non-coding RNA profile in lung cancer

Lung cancer is the most frequently diagnosed malignancy and the leading source of cancer-associated mortality. This kind of cancer has heterogeneous nature and is divided into two broad classes of small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). In addition to aberrant expression of several signaling pathways and oncogenes, lung cancer is associated with dysregulation of expression of non-coding RNAs including both long non-coding RNAs (lncRNAs) and miRNAs. These aberrantly expressed transcripts are putative therapeutic targets and diagnostic/ prognostic markers. Integrative assessment of expression of lncRNAs, miRNAs and mRNAs has led to construction of competing endogenous RNA networks in which several lncRNAs act as molecular sponges to inhibit regulatory function of miRNAs on mRNAs. Notably, some of these networks seem to have subtype-specific functions in lung cancer. In this review, we summarize recent findings about the importance of these networks in the pathogenesis of lung cancer and provide a list of onco-miRNAs, tumor suppressor miRNAs, oncogenic lncRNAs and tumor suppressor lncRNAs based on their roles in the carcinogenic process in lung cancer.

LncRNA HOXB-AS1 promotes cell growth in multiple myeloma via FUT4 mRNA stability by ELAVL1

Multiple myeloma (MM) is defined as the second most common hematological tumor in the globe. Long noncoding RNAs (lncRNAs) have been reported to play stimulative or suppressive role in the progression of different carcinomas. The investigation of lncRNAs in MM is still inadequate. LncRNA HOXB cluster antisense RNA 1 (HOXB-AS1) was once revealed to facilitate glioma progression by affecting cellular activities of glioma cells. However, whether HOXB-AS1 participates in the development of MM still remains an enigma. In this study, we unveiled that HOXB-AS1 was highly expressed in MM and loss-of-function assays certified that HOXB-AS1 obstruction suppressed MM cell proliferation, and stimulated cell apoptosis. In addition, HOXB-AS1 could modulate fucosyltransferase 4 (FUT4) and FUT4-mediated Wnt/β-catenin pathway. In subsequence, it was observed from mechanism assays that HOXB-AS1 enhanced the interaction between ELAVL1 and FUT4 so as to stabilize FUT4 messenger RNA. In the end, rescue experiments affirmed that HOXB-AS1 affected the cell growth through FUT4 in MM. In conclusion, the whole modulation mechanism of HOXB-AS1/ELAVL1/FUT4 axis in MM was validated in this study, which suggested that HOXB-AS1 might function as a powerful and promising therapeutic biomarker for the clinical treatment of patients with MM.

Long Noncoding RNA MNX1 antisense RNA 1 Exerts Oncogenic Functions in Bladder Cancer by Regulating miR-218-5p/RAB1A Axis

LncRNA MNX1 antisense RNA 1 (MNX1-AS1) is significantly overexpressed in patients with bladder cancer, suggesting that it might be associated with bladder cancer. However, the molecular mechanism of MNX1-AS1 in bladder cancer remained indistinct. To illustrate the role of MNX1-AS1 in bladder cancer, the gain- and loss-of-function experiments were conducted in bladder cancer cells. Reduced expression of MNX1-AS1 could suppress cell proliferation, migration, invasion, and epithelial-mesenchymal transition in bladder cancer cells, whereas overexpression of MNX1-AS1 resulted in the opposite effects. Mechanistic analysis demonstrated that miR-218-5p was a direct target of RAB1A. MNX1-AS1 could competitively bind to miR-218-5p to regulate RAB1A expression in bladder cancer cells. Furthermore, in vivo experiments revealed that reduced expression of MNX1-AS1 inhibited tumor growth and metastasis. Taken together, MNX1-AS1 functions as a sponge to miR-218-5p to modulate RAB1A expression in bladder cancer, which suggests that MNX1-AS1 might serve as a novel therapeutic target and a novel biomarker for metastasis and prognosis in bladder cancer. SIGNIFICANCE STATEMENT: Our study demonstrates that long noncoding RNA MNX1-AS1 promotes the initiation and progression of bladder cancer. MNX1-AS1 regulates RAB1A expression to promote proliferation, migration, invasion, and epithelial-mesenchymal transitions of bladder cancer cells via miR-218-5p, which contributes to the tumor growth and metastasis of bladder cancer. Collectively, these results suggest that MNX1-AS1 might serve as a potential biomarker for bladder cancer.

PITPNA-AS1 abrogates the inhibition of miR-876-5p on WNT5A to facilitate hepatocellular carcinoma progression

LncRNA PITPNA-AS1 was a newly identified lncRNA which has never been studied in cancers. Whether PITPNA-AS1 participated in the development of hepatocellular carcinoma (HCC) is obscure. Given the coaction of lncRNAs and miRNAs to carcinogenesis, the purpose of the present research is to inquire how PITPNA-AS1 affects HCC progression. Firstly, PITPNA-AS1 was observed to be heightened in HCC tissues. Then function assays proved that overexpressing or silencing PITPNA-AS1 could manipulate the proliferation and motility of HCC cells. Besides, PITPNA-AS1 was located in the cytoplasm. Among the candidate miRNAs of PITPNA-AS1, miR-876-5p was an obvious target. Moreover, mechanism experiments validated that PITPNA-AS1 modulated WNT5A expression by targeting miR-876-5p. Rescue experiments affirmed that WNT5A silencing rescued the miR-876-5p suppression-induced cellular processes in PITPNA-AS1-silenced Hep3B cells. And in vivo experiments determined that PITPNA-AS1 regulated HCC progression in vivo via miR-876-5p/WNT5A pathway. In conclusion, this work shed lights on the modulatory mechanism of PITPNA-AS1/miR-876-5p/WNT5A axis in HCC, which might be pivotal for exploring effective diagnostic biomarkers and treatment strategies for HCC patients.

YY1-mediated overexpression of long noncoding RNA MCM3AP-AS1 accelerates angiogenesis and progression in lung cancer by targeting miR-340-5p/KPNA4 axis

Lung cancer is famous as an aggressive malignant tumor and is the main cause of cancer-associated mortality globally. Tumor angiogenesis is a vital part in cancer, which influences cell proliferation and metastasis. Increasing studies have claimed that long noncoding RNAs (lncRNAs) were involved in the progression of several cancers. Based on previous studies, this study focused on the role and mechanism of lncRNA MCM3AP antisense RNA 1 (MCM3AP-AS1) in lung cancer. At first, MCM3AP-AS1 expression was found to be elevated in lung cancer cells. Depletion of MCM3AP-AS1 repressed cell proliferation, migration, and angiogenesis in lung cancer cells. YY1 was confirmed to mediate MCM3AP-AS1 transcription in lung cancer cells. Moreover, the molecular mechanism investigation revealed that MCM3AP-AS1 could sponge miR-340-5p and elevate KPNA4 expression. On the basis of rescue assays, we identified that the overexpression of KPNA4 partly counteracted the suppressed effect of MCM3AP-AS1 knockdown on angiogenesis and progression in lung cancer cells. Conclusively, the YY1-mediated overexpression of MCM3AP-AS1 accelerated angiogenesis and progression in lung cancer by targeting miR-340-5p/KPNA4 axis, which highlighted the possibility of MCM3AP-AS1 as a promising therapeutic target for lung cancer.

Double mutation of BRF1 and BRF2 leads to sterility in Arabidopsis thaliana

The TFIIB-related factor (BRF) family plays vital roles in RNA polymerase (Pol) III transcription initiation. However, little is known about the role of BRF in plants. Here, we report BRF1 and BRF2 are involved in Arabidopsis reproduction. In this study, we generated BRF1 and BRF2 double mutant plants. We found that no homozygous double mutants of brf1brf2 were obtained when brf1 and brf2 were crossed, although brf1 and brf2 mutants individually developed and reproduced normally. Further experiments revealed that heterozygous brf1/ + brf2/ + produced abnormal pollen and had no seeds in some placentas of siliques. Genetic data derived from reciprocal crosses showed that BRF2 plays a dominant role in Arabidopsis reproduction. Taken together, a double mutation of BRF1 and BRF2 results in a high degree of aborted macrogametes and microgametes and complete failure in zygote generation, ultimately leading to sterility.

LINC00958 regulated miR-627-5p/YBX2 axis to facilitate cell proliferation and migration in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC), the subtype of head and neck cancers, is notorious for its high incidence and death rate. The role of long non-coding RNAs (lncRNAs) is discovered to be significant for the canceration and cancer progression. Long intergenic non-protein coding RNA 958 (LINC00958) is discovered as a carcinogene in multiple cancers, such as gastric cancer, pancreatic cancer, and glioma, but there has been no report about how LINC00958 functions in OSCC. The objective of our study is to unfold function and mechanism investigation on LINC00958 in OSCC. First, TCGA database showed the upregulation and prognostic significance of LINC00958 in head and neck squamous carcinoma. Then, we discovered in OSCC clinical samples that LINC00958 presented high expression and predicted poor prognosis. Also, LINC00958 was elevated in OSCC cells. In vitro gain- and loss-function experiments proved that LINC00958 facilitated cell growth, retarded apoptosis, accelerated migration, and epithelial-to-mesenchymal transition (EMT) in OSCC. Mechanistically, we confirmed the cytoplasmic expression of LINC00958 in OSCC cells, and revealed that LINC00958 sequestered miR-627-5p to upregulate YBX2 expression. Rescue assays indicated that LINC00958 regulated OSCC cell proliferation, motility and EMT through YBX2. Together, we showed that LINC00958 promoted OSCC progression through miR-627-5p/YBX2 axis, indicating LINC00958 as a new prognostic marker, and provided new perspectives for molecular targeted treatment for OSCC.

LncRNA MNX1-AS1 promotes progression of esophageal squamous cell carcinoma by regulating miR-34a/SIRT1 axis

BACKGROUND

Long non-coding RNAs (lncRNAs) are powerful factors influencing the tumorigenesis and metastasis of multiple carcinomas. LncRNA MNX1-AS1 plays critical roles in the progression of tumor formation according to recent research, while its roles in esophageal squamous cell carcinoma (ESCC) remains unknown.

METHODS

The expression levels of lncRNA MNX1-AS1 were examined in ESCC tissues by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The role of lncRNA MNX1-AS1 was performed by WST-1 proliferation assays, migration and invasion assays. Besides, the molecular mechanism of lncRNA MNX1-AS1 was verified by online bioinformatics, qRT-PCR and rescue assays.

RESULTS

MNX1-AS1 was signifcantly upregulated in ESCC tissues. It was conformed that high MNX1-AS1 expression was associated with ESCC lymph node metastasis. Moreover, we found that knockdown of MNX1-AS1 apparently suppressed the cell proliferation, migration, and invasion capacity. Flow cytometry analysis showed MNX1-AS1 regulated ESCC cell cycle and apoptosis progression. Mechanism analysis revealed that miR-34a inhibitor could rescue the influence of inhibiting MNX1-AS1 on ESCC cells migration by serving as competing endogenous RNA (ceRNAs). Furthermore, we found that miR-34a specifically targeted SIRTI.

CONCLUSIONS

Taken together, we demonstrated that lncRNA MNX1-AS1/miR-34a/SIRT1 regulatory axis could play an important role in ESCC progression, and MNX1-AS1 may act as a novel potential biomarker for esophageal squamous cell carcinoma.