microRNA‐448 inhibits the progression of non‐small–cell lung cancer through regulating IRS2

LincRNA PRNCR1 activates the Wnt/β-catenin pathway to drive the deterioration of hepatocellular carcinoma via regulating miR-411-3p/ZEB1 axis

Hepatocellular carcinoma (HCC) is an intractable malignant disease with high incidence rate annually. LincRNA PRNCR1 has been confirmed as a tumor supporter, while its functions in HCC remain unclear. This study aims to explore the mechanism of LincRNA PRNCR1 in hepatocellular carcinoma. The qRT-PCR was applied to the quantification of non-coding RNAs. Cell counting Kit-8 (CCK-8), Transwell assay and flow cytometry assay were applied to reflect the change in the phenotype of HCC cells. Moreover, the databases including Targetscan and Starbase and dual-luciferase reporter assay were applied to investigate the interaction of the genes. The western blot was applied to detect the abundance of proteins and the activity of the related pathways. Elevated LincRNA PRNCR1 was dramatically upregulated in HCC pathological samples and cell lines. MiR-411-3p served as a target of LincRNA PRNCR1, and decreased miR-411-3p was found in the clinical samples and cell lines. LincRNA PRNCR1 downregulation could induce the expression of miR-411-3p, and LincRNA PRNCR1 silence could impede the malignant behaviors via increasing the abundance of miR-411-3p. Zinc finger E-box binding homeobox 1 (ZEB1) was confirmed as a target of miR-411-3p, which remarkably upregulated in HCC cells, and ZEB1 upregulation could significantly rescue the effect of miR-411-3p on malignant behaviors of HCC cells. Moreover, LincRNA PRNCR1 was confirmed to involve the Wnt/β-catenin pathway via regulating miR-411-3p/ZEB1 axis. This study suggested that LincRNA PRNCR1 could drive the malignant progression of HCC via regulating miR-411-3p/ZEB1 axis.

ASPSCR1::TFE3-mediated upregulation of insulin receptor substrate 2 (IRS-2) activates PI3K/AKT signaling and promotes malignant phenotype

The ASPSCR1::TFE3 fusion gene, resulting from chromosomal translocation, is detected in alveolar soft part sarcoma (ASPS) and a subset of renal cell carcinomas (RCC). The ASPSCR1::TFE3 oncoprotein, functioning as an aberrant transcription factor, contributes to tumor development and progression by inappropriately upregulating target genes. Here, we identified insulin receptor substrate 2 (IRS-2), a cytoplasmic adaptor protein, as a novel transcriptional target of ASPSCR1::TFE3. Ectopic expression of ASPSCR1::TFE3 led to increased IRS-2 mRNA and protein levels. Chromatin immunoprecipitation and luciferase assays demonstrated that ASPSCR1::TFE3 bound to the IRS-2 promoter region and enhanced its transcription. Moreover, IRS-2 was highly expressed in the ASPSCR1::TFE3-positive RCC cell line FU-UR1, while small interfering RNA-mediated depletion of ASPSCR1::TFE3 markedly decreased IRS-2 mRNA and protein levels. Functionally, IRS-2 knockdown attenuated activation of the PI3K/AKT pathway and reduced proliferation, migration, invasion, adhesion, and clonogenicity in FU-UR1 cells. Pharmacological inhibition of IRS-2 also reduced AKT activation as well as cell viability, clonogenicity, migration, invasion, and adhesion. These findings suggest that IRS-2, regulated by ASPSCR1::TFE3, promotes tumor progression by activating PI3K/AKT signaling and enhancing the malignant phenotype.

Regulation and therapeutic potentials of microRNAs to non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, accounting for 80%-85% of total cases and leading to millions of deaths worldwide. Drug resistance is the primary cause of treatment failure in NSCLC, which urges scientists to develop advanced approaches for NSCLC treatment. Among novel approaches, the miRNA-based method has emerged as a potential approach as it allows researchers to modulate target gene expression. Subsequently, cell behaviors are altered, which leads to the death and the depletion of cancer cells. It has been reported that miRNAs possess the capacity to regulate multiple genes that are involved in various signaling pathways, including the phosphoinositide 3-kinase, receptor tyrosine kinase/rat sarcoma virus/mitogen-activated protein kinase, wingless/integrated, retinoblastoma, p53, transforming growth factor β, and nuclear factor-kappa B pathways. Dysregulation of these signaling pathways in NSCLC results in abnormal cell proliferation, tissue invasion, and drug resistance while inhibiting apoptosis. Thus, understanding the roles of miRNAs in regulating these signaling pathways may enable the development of novel NSCLC treatment therapies. However, a comprehensive review of potential miRNAs in NSCLC treatment has been lacking. Therefore, this review aims to fill the gap by summarizing the up-to-date information on miRNAs regarding their targets, impact on cancer-associated pathways, and prospective outcomes in treating NSCLC. We also discuss current technologies for delivering miRNAs to the target cells, including virus-based, non-viral, and emerging extracellular vesicle-based delivery systems. This knowledge will support future studies to develop an innovative miRNA-based therapy and select a suitable carrier to treat NSCLC effectively.

CirRNA circFAM126A Exerts Oncogenic Functions in NSCLC to Upregulate IRS2

Non-small cell lung cancer (NSCLC) is a common histological subtype of lung cancer, which occupies 80-85% of the proportion in all lung cancer cases. Therefore, this study was designed to clarify the role and underlying molecular mechanisms of circFAM126A in NSCLC. The real-time quantitative polymerase chain reaction (RT-qPCR) assay was conducted to assess circFAM126A, FAM126A, miR-613, and IRS2 expression in NSCLC tissues and cells. The proliferation ability of cells was measured by MTT, EdU, and colony-forming assays. The flow cytometry assay was performed to evaluate cell cycle distribution and apoptosis of NSCLC cells. The migration and invasion were determined by wound healing and transwell matrigel assays, respectively. The interaction relationship between miR-613 and circFAM126A or IRS2 was analyzed by dual-luciferase reporter and RNA pull-down assays. Tumorigenesis in nude mice was conducted to clarify the functional roles of circFAM126A inhibition in vivo. CircFAM126A was obviously overexpressed in NSCLC tissues and cells when compared with controls. The loss-of-functional experiments suggested that knockdown of circFAM126A suppressed proliferation, migration and invasion, as well as caused apoptosis and cell cycle arrest in NSCLC cells, which was abolished by silencing of miR-613. In addition, IRS2 was a target gene of miR-613. Overexpression of miR-613 exerted carcinoma inhibitor role in NSCLC by inhibition of IRS2 expression. Consistently, the silencing of circFAM126A also functioned anti-tumorigenic roles in nude mice in vivo. Mechanistically, circFAM126A could function as a miRNA sponge for miR-613 to regulate the expression of IRS2, thereby regulating proliferation, migration, invasion, apoptosis, and cell cycle arrest in NSCLC cells.

Long non-coding RNA AK006774 inhibits cardiac ischemia-reperfusion injury via sponging miR-448

In recent years, the incidence and mortality of myocardial infarction (MI) have been increasing throughout the world, threatening public health. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), play critical roles in the progression of MI. The present study aimed to investigate the role of lncRNA AK006774 in the progression of myocardial infarction and find out novel therapeutic or diagnostic target of myocardial infarction. A mouse ischemia/reperfusion (I/R) model and 2,3,5-Triphenyte-trazoliumchloride (TTC) staining were performed to evaluate the effects of AK006774 on I/R injury in vivo. Hypoxia/reoxygenation (H/R) models using primary cardiomyocytes have been established. Flow cytometry and Terminal Deoxynucleotide Transferase dUTP Nick End Labeling (TUNEL) assays were performed to evaluate the effects of AK006774 on cardiomyocyte apoptosis. Luciferase and RNA pull-down assays were performed to verify the interaction between miR-448 and its targets. Western blotting and quantitative PCR were performed to determine protein and gene expression, respectively. We first found that AK006774 overexpression reduced I/R-induced infarct area and cardiomyocyte apoptosis in vivo. Accordingly, AK006774 inhibited apoptosis and oxidative stress in cardiomyocytes subjected to H/R treatment in vitro. Mechanistically, AK006774 modulated the expression of bcl-2 by sponging miR-448. Overexpression of miR-448 antagonized the effects of AK006774 on cardiomyocyte apoptosis. The AK006774/miR-448/bcl-2 signaling axis acts as a key regulator of I/R injury and may be a potential therapeutic or diagnostic target for the treatment of MI.

KDM5B promotes self-renewal of hepatocellular carcinoma cells through the microRNA-448-mediated YTHDF3/ITGA6 axis

Histone methylation plays important roles in mediating the onset and progression of various cancers, and lysine-specific demethylase 5B (KDM5B), as a histone demethylase, is reported to be an oncogene in hepatocellular carcinoma (HCC). However, the mechanism underlying its tumorigenesis remains undefined. Hence, we explored the regulatory role of KDM5B in HCC cells, aiming to identify novel therapeutic targets for HCC. Gene Expression Omnibus database and StarBase were used to predict important regulatory pathways related to HCC. Then, the expression of KDM5B and microRNA-448 (miR-448) in HCC tissues was detected by RT-qPCR and Western blot analysis. The correlation between KDM5B and miR-448 expression was analysed by Pearson's correlation coefficient and ChIP experiments, and the targeting of YTH N6-methyladenosine RNA binding protein 3 (YTHDF3) by miR-448 was examined by luciferase assay. Additionally, the effect of KDM5B on the proliferation, migration, invasion and apoptosis as well as tumorigenicity of transfected cells was assessed using ectopic expression and depletion experiments. KDM5B was highly expressed in HCC cells and was inversely related to miR-448 expression. KDM5B demethylated H3K4me3 on the miR-448 promoter and thereby inhibited the expression of miR-448, which in turn targeted YTHDF3 and integrin subunit alpha 6 (ITGA6) to promote the malignant phenotype of HCC. Moreover, KDM5B accelerated HCC progression in nude mice via the miR-448/YTHDF3/ITGA6 axis. Our study uncovered that KDM5B regulates the YTHDF3/ITGA6 axis by inhibiting the expression of miR-448 to promote the occurrence of HCC.

Crosstalk of long non-coding RNAs and EMT: Searching the missing pieces of an incomplete puzzle for lung cancer therapy

BACKGROUND

Lung cancer is considered to be the first place among the cancer-related deaths worldwide and demands novel strategies in the treatment of this life-threatening disorder. The aim of this review is to explore regulation of epithelial-to-mesenchymal transition (EMT) by long non-coding RNAs (lncRNAs) in lung cancer.

INTRODUCTION

LncRNAs can be considered as potential factors for targeting in cancer therapy, since they regulate a bunch of biological processes, e.g. cell proliferation, differentiation and apoptosis. The abnormal expression of lncRNAs occurs in different cancer cells. On the other hand, epithelial-to-mesenchymal transition (EMT) is a critical mechanism participating in migration and metastasis of cancer cells.

METHOD

Different databases including Googlescholar, Pubmed and Sciencedirect were used for collecting articles using keywords such as "LncRNA", "EMT", and "Lung cancer".

RESULT

There are tumor-suppressing lncRNAs that can suppress EMT and metastasis of lung cancer cells. Expression of such lncRNAs undergoes down-regulation in lung cancer progression and restoring their expression is of importance in suppressing lung cancer migration. There are tumor-promoting lncRNAs triggering EMT in lung cancer and enhancing their migration.

CONCLUSION

LncRNAs are potential regulators of EMT in lung cancer, and targeting them, both pharmacologically and genetically, can be of importance in controlling migration of lung cancer cells.

MicroRNA-448 targets SATB1 to reverse the cisplatin resistance in lung cancer via mediating Wnt/β-catenin signalling pathway

This study aims to examine whether miR-448 reverses the cisplatin (DDP) resistance in lung cancer by modulating SATB1. QRT-PCR and immunohistochemistry were used to examine the miR-448 and SATB1 expressions in DDP-sensitive and -resistant lung cancer patients. A microarray was used to investigate the cytoplasmic/nucleic ratio (C/N ratios) of genes in A549 cells targeted by miR-448, followed by Dual-luciferase reporter gene assay. A549/DDP cells were transfected with miR-448 mimics/inhibitors with or without SATB1 siRNA followed by MTT assay, Edu staining, flow cytometry, qRT-PCR and western blotting. MiR-448 was lower but SATB1 was increased in DDP-resistant patients and A549/DDP cells. And the patients showed low miR-448 expression or SATB1 positive expression had poor prognosis. SATB1, as a target gene with higher C/N ratios (>1), was found negatively regulated by miR-448. Besides, miR-448 inhibitors increased resistance index of A549/DDP cells, promoted cell proliferation, increased cell distribution in S phrase, declined cell apoptosis and activated Wnt/β-catenin pathway. However, SATB1 siRNA could reverse the above effect caused by miR-448 inhibitors. MiR-448 targeting SATB1 to counteract the DDP resistance of lung cancer cells via Wnt/β-catenin pathway.

circRNA Hsa_circ_0020850 Silence Represses the Development of Lung Adenocarcinoma via Regulating miR-195-5p/IRS2 Axis

Background

The dysregulated circular RNAs (circRNAs) are relevant to lung adenocarcinoma development. Nevertheless, the function and mechanism of hsa_circ_0020850 (circ_0020850) in lung adenocarcinoma development are uncertain.

Methods

A total of 35 lung adenocarcinoma patients were recruited, and the tumor and normal tissue samples were harvested. A549 and PC-9 cells were exhibited for the experiments in vitro. circ_0020850, microRNA-195-5p (miR-195-5p) and insulin receptor substrate 2 (IRS2) abundances were detected via quantitative reverse transcription-polymerase chain reaction or Western blot. Cell proliferation, apoptosis, migration and invasion were measured via cell counting kit-8 (CCK8) assay, colony formation, flow cytometry, transwell and Western blot. The relationship between miR-195-5p and circ_0020850 or IRS2 was tested via dual-luciferase reporter analysis. The function of circ_0020850 on cell growth in vivo was measured via xenograft model.

Results

circ_0020850 expression was enhanced in lung adenocarcinoma tissues and cells. circ_0020850 silence suppressed cell proliferation, migration and invasion and facilitated apoptosis. miR-195-5p was targeted via circ_0020850, and its knockdown reversed the inhibitive effect of circ_0020850 silence on lung adenocarcinoma development. IRS2 was targeted via miR-195-5p, and miR-195-5p inhibited cell proliferation, migration and invasion and induced apoptosis via decreasing IRS2. circ_0020850 knockdown decreased IRS2 expression via regulating miR-195-5p. circ_0020850 down-regulation decreased lung adenocarcinoma xenograft tumor growth.

Conclusion

circ_0020850 knockdown repressed lung adenocarcinoma cell proliferation, migration and invasion and promoted apoptosis via regulating miR-195-5p and IRS2.

RETRACTED: KDM5B-mediated microRNA-448 up-regulation restrains papillary thyroid cancer cell progression and slows down tumor growth via TGIF1 repression

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Transwell assay results shown in Figures 3G, 6F, and 7F, which appear to contain image similarities within some of the panels, as detailed here: https://pubpeer.com/publications/7680482DF471CF3FADB2D14154BCFF and here: https://docs.google.com/spreadsheets/d/1r0MyIYpagBc58BRF9c3luWNlCX8VUvUuPyYYXzxWvgY/edit#gid=262337249. In addition, several suspected image similarities were detected within the whole brain images in Figure 7I, and within the Transwell assays of Figure 7G. The journal requested the corresponding author comment on these concerns and provide the raw data. However, the authors were not able to satisfactorily fulfill this request and therefore the Editor-in-Chief decided to retract the article.

Circ_0000003 promotes the proliferation and metastasis of non-small cell lung cancer cells via miR-338-3p/insulin receptor substrate 2

Background: Circular RNAs (circRNAs) play a pivotal regulatory role in a variety of tumors.Nevertheless, the detailed function of circ_0000003 in non-small cell lung cancer (NSCLC) and its regulatory mechanism remain elusive.Methods: RT-PCR was carried out to detect the expressions of circ_0000003, miR-338-3p and insulin receptor substrate 2 (IRS2)in NSCLC tissues. Besides, western blot was done to monitor IRS2 expression in NSCLC cells. The correlation between circ_0000003 and clinicopathologic characteristics of NSCLC patients was analyzed as well.CCK8 and BrdUassays were used to monitor cell proliferation; flow cytometry was used to detect apoptosis; and transwell assay was conducted to detect its migration and invasion.Moreover, dual luciferase reporter gene assay was done to verify the targeting relationship between circ_0000003 and miR-338-3p.Additionally, the effect of circ_0000003 on the growth of NSCLC cells in vivo was evaluated by tumorigenesis assay in nude mice.Results: The expression of circ_0000003 was significantly high in NSCLC tissues and cell lines, and its high expression level was notably correlated with lymph node metastasis andTNM staging.In vitro experiments showed that overexpression of circ_0000003 facilitated the proliferation, migration, invasion and inhibited the apoptosis of NSCLC cells, while the knockdown of circ_0000003 had the opposite effect.In vivo experiments revealed that knockdown of circ_0000003 impeded tumor growth and metastasis. Further, the underlying mechanism showed that circ_0000003 functioned as endogenous competitive RNA and directly targeted miR-338-3p to positively regulated IRS2 expression.Conclusion: Circ_0000003 promotes the proliferation and metastasis of NSCLC cells via modulating miR-338-3p/IRS2 axis.

MicroRNA‑718 serves a tumor‑suppressive role in non‑small cell lung cancer by directly targeting CCNB1

MicroRNA‑718 (miR‑718) serves crucial roles in tumorigenesis and in the progression of a number of cancers. However, the expression profile, specific functions and mechanisms of action of miR‑718 in non‑small cell lung cancer (NSCLC) are still elusive. The aims of the present study were to quantify the expression of miR‑718, determine its biological roles and elucidate the molecular mechanisms responsible for its activities in NSCLC cells. Reverse transcription‑quantitative PCR was carried out to assess miR‑718 expression in NSCLC tissue samples and cell lines. The Cell Counting Kit‑8 assay, flow cytometry, cell migration and invasion assays, and a tumor xenograft experiment were performed to evaluate the effects of miR‑718 overexpression on the malignant biological behaviors of NSCLC cells. miR‑718 expression was demonstrated to be significantly decreased in NSCLC tissue samples and cell lines. This reduced expression was significantly associated with tumor, node, metastasis stage, tumor size, lymph node metastasis and poor overall survival among patients with NSCLC. Exogenous miR‑718 expression suppressed NSCLC cell proliferation, migration and invasion, and promoted apoptosis in vitro; whereas it hindered tumor growth in vivo. Experiments to elucidate the mechanisms involved revealed that miR‑718 functions by directly targeting cyclin B1 (CCNB1) mRNA. CCNB1 expression was found to be upregulated in NSCLC and inversely correlated with miR‑718 levels. CCNB1 depletion had effects similar to those of miR‑718 overexpression in NSCLC cells. Furthermore, restoration of CCNB1 expression attenuated the tumor‑suppressive effects of miR‑718 overexpression in NSCLC cells. These results indicated that miR‑718 suppressed NSCLC progression in vitro and in vivo by directly targeting CCNB1 mRNA, which may indicate a potential target for the diagnosis and treatment of this fatal disease.