Depletion of circ_0006459 protects human brain microvascular endothelial cells from oxygen-glucose deprivation-induced damage through the miR-940/FOXJ2 pathway

BACKGROUND

Multiple circular RNAs (circRNAs) play important roles in ischemic stroke. The present study aims to reveal the role and the mechanism of circ_0006459 in ischemic stroke.

METHODS

Human brain microvascular endothelial cells (HBMECs) were treated with oxygen-glucose deprivation (OGD) to mimic an in vitro ischemic stroke model. RNA expression of circ_0006459, microRNA-940 (miR-940), and forkhead box J2 (FOXJ2) was detected by quantitative real-time polymerase chain reaction. Cell proliferation was analyzed by cell counting kit-8 (CCK-8) and 5-Ethynyl-29-deoxyuridine (EdU) assays. Cell apoptotic rate was quantified by flow cytometry analysis. The protein expression of proliferating cell nuclear antigen (PCNA), clusters of differentiation 6 (CDK6), BCL2-associated x protein (Bax), B-cell lymphoma 2 (Bcl2), interleukin-1β (IL-1β), IL-8, IL-18 and tumor necrosis factor-α (TNF-α) was analyzed by Western blotting. The regulatory relationships among circ_0006459, miR-940, and F 《》 OXJ2 were identified by dual-luciferase reporter assay, RNA immunoprecipitation assay, and RNA pull-down assay.

RESULTS

Circ_0006459 and FOXJ2 expression were significantly upregulated, whereas miR-940 expression was downregulated in HBMECs after OGD. Circ_0006459 depletion assuaged OGD-induced inhibition in cell proliferation and promotion in cell apoptosis and inflammation in HBMECs. Circ_0006459 acted as a sponge for miR-940, and miR-940 targeted FOXJ2 in HBMECs. Besides, miR-940 silencing or FOXJ2 overexpression relieved circ_0006459 knockdown-induced promotion in cell proliferation and inhibition in cell apoptosis and inflammation in OGD-induced HBMECs. Further, circ_0006459 depletion decreased FOXJ2 protein expression by interacting with miR-940.

CONCLUSION

Depletion of circ_0006459 protected human brain microvascular endothelial cells from oxygen-glucose deprivation-induced damage through miR-940/FOXJ2 pathway, providing a promising therapeutic target for ischemic stroke.

Optimization of a method for the clinical detection of serum exosomal miR-940 as a potential biomarker of breast cancer

Serum exosomal microRNAs (miRNAs) are potential biomarkers for tumor diagnosis. Clinically, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) can be used to determine the expression of exosomal miRNAs in the serum of breast cancer patients. The prerequisites for obtaining meaningful serum exosomal miRNA data of breast cancer patients include a suitable extraction method for exosomes and RT-qPCR data standardized by internal reference genes. However, the appropriate methods for the extraction of exosomes and the applicability of reference genes for analyzing exosomal miRNAs in breast cancer patients remain to be studied. This study compared the effects of three exosome extraction methods as well as the expression of exosomal miRNA in different initial serum amounts and at different serum states to identify the selection of the best method for serum exosome extraction. Five candidate reference genes including miR-16, miR-484, miR-1228, miR-191 and miR-423 for standardizing serum exosomal miRNAs were screened using five algorithms and were used for the quantification of serum exosomal miR-940. Significant downregulation of serum exosomal miR-940 expression in breast cancer was detected using miR-191 and miR-1228, whereas no significant down or up regulation was observed with miR-484, miR-423 and miR-16. Previous studies have shown that the expression level of miR-940 is downregulated in breast cancer tissues. The absolute quantitative results showed that miR-940 was significantly downregulated in breast cancer serum exosomes, which was consistent with the results from the analysis using miR-191 or miR-1228 as reference genes. Therefore, miR-191 and miR-1228 could serve as reference genes for the relative quantification of serum exosomal miRNAs. This finding indicated the importance of rigorously evaluating the stability of reference genes and standardization for serum exosomal miRNA expression. Moreover, the level of serum exosomal miR-940 in breast cancer could reflect the presence of lymph node metastasis and the status of HER2/neu, which indicates its potential as a biomarker for breast cancer metastasis. In summary, an optimized protocol for the detection of serum exosomal miR-940 as a breast cancer marker was preliminarily established.

Circ_0020123 promotes NSCLC tumorigenesis via up-regulating KIAA1522 expression through miR-940

Circ_0020123 was highly expressed in NSCLC tissues and cell lines, and knockdown of circ_0020123 abolished cell growth, migration and invasion in vitro and hindered tumor growth in nude mice. Mechanically, circ_0020123 directly targeted miR-940, and KIAA1522 was a target of miR-940. Thereafter, a series of rescue experiments showed that circ_0020123 served its biological functions by miR-940/KIAA1522 axis. In all, circ_0020123 acted as an oncogene to promote the tumorigenesis of NSCLC via miR-940/KIAA1522 axis, suggesting a potential therapeutic target for NSCLC treatment.

LncRNA GATA2-AS1 suppresses esophageal squamous cell carcinoma progression via the mir-940/PTPN12 axis

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor worldwide. Long noncoding RNAs (lncRNAs) exhibit a regulatory role in the progression of ESCC. Our research was performed to investigate the potential molecular mechanism of lncRNA GATA2-AS1 in ESCC.

METHODS

The expression of GATA2-AS1 was identified by qRT-PCR. Cell function assays explored the potential effect of GATA2-AS1 on ESCC progression. The subcellular hierarchical localization method was executed to identify the subcellular localization of GATA2-AS1 in ESCC cells. A prediction website was utilized to discover the relationships among GATA2-AS1, miR-940 and PTPN12. Dual luciferase reporter gene, pull-down assays and RIP assays were executed to verify the binding activity among GATA2-AS1, miR-940 and PTPN12. Xenograft tumor experiments were performed to evaluate ESCC cell growth in vivo.

RESULTS

The expression of GATA2-AS1 and PTPN12 was reduced, while miR-940 expression was enhanced in ESCC tissues and cell lines. In vivo experiments showed that GATA2-AS1 inhibited the progression of ESCC cells toward malignancy. Bioinformatics analysis, dual luciferase and RIP assays revealed that GATA2-AS1 upregulated PTPN12 expression by competitively targeting miR-940. miR-940 reversed the inhibitory effect of GATA2-AS1 on the biological behavior of ESCC cells.

CONCLUSION

Our findings suggested that GATA2-AS1, expressed at low levels in ESCC, plays a crucial role in the progression of ESCC by targeting the miR-940/PTPN12 axis and could be a potential drug target to treat ESCC patients.

Zinc finger Asp-His-His-Cys palmitoyl -acyltransferase 19 accelerates tumor progression through wnt/β-catenin pathway and is upregulated by miR-940 in osteosarcoma

Osteosarcoma (OS) is the most frequent malignant primary bone tumor in children and young adults. Zinc finger Asp-His-His-Cys palmitoyl-acyltransferase 19 (ZDHHC19) is a key enzyme in protein palmitoylation and plays crucial roles in tumor progression. However, its expression profile and biological function in OS have been unclear. In the present study, the expression level of ZDHHC19 in OS cell lines was determined by qRT-PCR and Western blot. The effect of ZDHHC19 in cell growth, invasion and migration was analyzed by CCK8, EDU, transwell, wound healing assay in vitro, and xenograft tumor model in vivo. In addition, bioinformatics analysis was used to explore the potential mechanism of ZDHHC19 in OS. Furthermore, the luciferase reporter assay was conducted to determine the direct binding between miR-940 and ZDHHC19. We discovered that ZDHHC19 was overexpressed in OS cells compared with the normal cells. The functional investigation demonstrated that ZDHHC19 silencing could inhibit proliferation, invasion and migration of OS in vitro and suppress tumorigenicity and lung metastasis in a xenograft model in vivo. Mechanistically, we identified that ZDHHC19 was a direct target of miR-940 and forced ZDHHC19 expressions partially rescue the suppression of proliferation, migration and invasion induced by miR-940. Moreover, bioinformatics analysis combined with validation experiments revealed that activating wnt/β-catenin pathway contributed to the pro-oncogenic effect induced by ZDHHC19. Furthermore, rescue experiments further verified that miR-940/ZDHHC19 axis regulated wnt/β-catenin pathway. Overall, these findings indicated that miR-940/ZDHHC19 axis played a significant role in OS progression and might be considered as a novel target for OS treatment.Abbreviations: OS, osteosarcoma; miRNAs, microRNAs; 3'-UTR, 3'- untranslated region; TARGET, Therapeutically Applicable Research To Generate Effective Treatments; qRT-PCR, quantitative real-time PCR; IHC, Immunohistochemistry; GSVA, Gene Set Variation Analysis; GSEA, Gene Set Enrichment Analysis; KEGG, Kyoto Encyclopedia of Genes and Genomes.

Circ_0003340 downregulation mitigates esophageal squamous cell carcinoma progression by targeting miR-940/PRKAA1 axis

Background

Esophageal squamous cell carcinoma (ESCC) is a highly prevalent type of esophageal cancer (EC), usually found at an advanced stage with a high mortality rate, and it is now crucial to find new ways to diagnose and treat ESCC. This study analyzed the function of circular RNA_0003340 (circ_0003340)/microRNA‐940 (miR‐940)/protein kinase AMP‐activated alpha 1 catalytic subunit (PRKAA1) axis in ESCC.

Methods

Circ_0003340, miR‐940 and PRKAA1 contents were measured with the application of real‐time quantitative polymerase chain reaction (RT‐qPCR) and western blot. Cell proliferation, cell cycle, apoptosis, migration, invasion and angiogenesis were assessed with a cell counting kit‐8 (CCK8), 5‐ethynyl‐2′‐deoxyuridine (EdU), flow cytometry, wound healing, transwell and tube formation assays. We used both the luciferase reporter system and RNA immunoprecipitation (RIP) to analyze the relationship between miR‐940 and circ_0003340 or PRKAA1. Finally, xenograft models were applied to analyze the effect of circ_0003340 on tumor growth in vivo.

Results

Upregulated circ_0003340 and PRKAA1, and downregulated miR‐940 levels were detected in ESCC. Meanwhile, ESCC progression was apparently restrained by circ_0003340 knockdown in vitro. Circ_0003340 acted as a ceRNA for miR‐940 in regulating ESCC progression and miR‐940 was proved to target PRKAA1 to arrest ESCC progression in vitro. Finally, in vivo experiments established that silencing of circ_0003340 slowed tumor growth in vivo.

Conclusion

Circ_0003340 downregulation mitigated esophageal squamous cell carcinoma progression by targeting miR‐940/PRKAA1 axis.

LncRNA THEMIS2-211, a tumor-originated circulating exosomal biomarker, promotes the growth and metastasis of hepatocellular carcinoma by functioning as a competing endogenous RNA

Hepatocellular carcinoma (HCC) is a major challenge for human health. Finding reliable diagnostic biomarkers and therapeutic targets for HCC is highly desired in the clinic. Currently, circulating exosomal lncRNA is a promising biomarker for the diagnosis of cancer and lncRNA is also a potential target in cancer therapy. Here, the diagnostic value of a panel based on exosomal lncRNA THEMIS2-211 and PRKACA-202, superior to that of AFP, was identified for diagnosing human HCC. Besides, the performance of exosomal lncRNA THEMIS2-211 alone exceeds that of AFP in diagnosing early-stage HCC patients (stage I). Furthermore, lncRNA THEMIS2-211 is highly expressed in HCC tissues and correlated with the poor prognosis of HCC patients. LncRNA THEMIS2-211 is upregulated and localized in the cytoplasm of HCC cells. LncRNA THEMIS2-211 exerts its biological function as an oncogene that promotes the proliferation, migration, invasion, EMT of HCC cells by physically interacting with miR-940 and therefore promoting SPOCK1 expressions. Rescue assays show the regulation of SPOCK1 by lncRNA THEMIS2-211 dependents on miR-940. The discovery of lncRNA THEMIS2-211 further illuminates the molecular pathogenesis of HCC and the THEMIS2-211/miR-940/SPOCK1 axis may act as a potential therapeutic target for HCC.

Hsa_circ_0062682 Promotes Serine Metabolism and Tumor Growth in Colorectal Cancer by Regulating the miR-940/PHGDH Axis

Colorectal cancer (CRC) is one of the most common malignancies globally. Increasing evidence indicates that circular RNAs (circRNAs) play a pivotal role in various cancers. The present study focused on exploring the role of a functionally unknown circRNA, hsa_circ_0062682 (circ_0062682), in CRC. By online analyses and experimental validations, we showed that circ_0062682 expression was aberrantly increased in CRC tissues compared with paired normal tissues. Increased expression of circ_0062682 in CRC notably correlated with a poor prognosis and advanced tumor stage. Functional experiments showed that circ_0062682 knockdown reduced CRC growth both in vitro and in vivo. Mechanistically, we revealed that circ_0062682 could sponge miR-940 and identified D-3-phosphoglycerate dehydrogenase (PHGDH), a key oxidoreductase involved in serine biosynthesis, as a novel target of miR-940. Silencing miR-940 expression could mimic the inhibitory effect of circ_0062682 knockdown on CRC proliferation. The expression of PHGDH was downregulated in circ_0062682-depleted or miR-940 overexpressing CRC cells at both the mRNA and protein levels. Circ_0062682 knockdown suppressed CRC growth by decreasing PHGDH expression and serine production via miR-940. Taken together, these data demonstrate, for the first time, that circ_0062682 promotes serine metabolism and tumor growth in CRC by regulating the miR-940/PHGDH axis, suggesting circ_0062682 as a potential novel therapeutic target for CRC.

MiR-940 Serves as a Diagnostic Biomarker in Patients with Sepsis and Regulates Sepsis-Induced Inflammation and Myocardial Dysfunction

Introduction

Sepsis is a heterogeneous syndrome with a life-long threat caused by infection. This study aimed to investigate the clinical function of miR-940 and its influence on cardiomyocyte models.

Methods

The relative expression of miR-940 was assessed by qRT-PCR and the roles in the clinical diagnosis of miR-940 were revealed by the ROC curve. The relationship between miR-940 and clinical parameters was validated by Pearson analysis. The sepsis rat models were established by treatment with cecal ligation and perforation (CLP) and clinical items including left ventricular systolic pressure (LVSP), left ventricular and end-diastolic pressure (LVEDP), maximum rate of increase/decrease in left ventricular blood pressure (± dp/dt_max) as well as troponin (cTnl), creatine kinase isoenzyme (CK-MB), TNF-α, IL-1β, and IL-6 were detected.

Results

The finding of qRT-PCR accentuated that the relative expression of miR-940 was significantly decreased in sepsis patients and CLP-stimulated models. The ROC curve proposed that miR-940 could be a satisfactory diagnostic biomarker for sepsis patients. Pearson analysis reinforced the expression of miR-940 was negatively associated with the PCT, WBC, CRP, Scr, SOFA score, and APACHE II score. The outcome of CLP-steered rat verified that overexpression of miR-940 inhibited the detrimental effects of CLP on myocardial dysfunction and inflammation reactions.

Conclusion

The downregulation of miR-940 was reported and it might be an underlying diagnostic marker in sepsis patients. Overexpression of miR-940 protected myocardial function from damage and inflammation induced by CLP.

miR-940 is a new biomarker with tumor diagnostic and prognostic value

miR-940 is a microRNA located on chromosome 16p13.3, which has varying degrees of expression imbalance in many diseases. It binds to the 3′ untranslated region (UTR) and affects the transcription or post-transcriptional regulation of target protein-coding genes. For a diversity of cellular processes, including cell proliferation, migration, invasion, apoptosis, epithelial-to-mesenchymal transition (EMT), cell cycle, and osteogenic differentiation, miR-940 can affect them not only by regulating protein-coding genes but also long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in pathways. Intriguingly, miR-940 participates in four pathways that affect cancer development, including the Wnt/β-catenin pathway, mitogen-activated protein kinase (MAPK) pathway, PD-1 pathway, and phosphatidylinositol 3-kinase (PI3K)-Akt pathway. Importantly, the expression of miR-940 is intimately correlated with the diagnosis and prognosis of tumor patients, as well as to the efficacy of tumor chemotherapy drugs. In conclusion, our main purpose is to outline the expression of miR-940 in various diseases and the molecular biological and cytological functions of target genes in order to reveal its potential diagnostic and prognostic value as well as its predictive value of drug efficacy.

MiR-940 promotes malignant progression of breast cancer by regulating FOXO3

Breast cancer (BC) is a common cancer with poor survival. The present study aimed to explore the effect of miR-940 on the process of BC cells and its target gene FOXO3. The expression of miR-940 was assessed in BC tissues and cells using qRT-PCR. Furthermore, the correlation between miR-940 and prognosis of BC patients from the TCGA database was analyzed. CCK8 assays and colony formation assays were used to explore the effect of miR-940 on BC cell proliferation. The invasion abilities were detected by transwell assays. Luciferase reporter assay was performed to scrutinize the relationship between miR-940 and FOXO3. Finally, rescue experiments were performed through FOXO3 down-regulation and miR-940 inhibitors by using CCK8 assays, colony formation assays and transwell assays. miR-940 was significantly up-regulated in BC cells and tissues. In addition, the high level of miR-940 correlated with poor survival of BC patients (P=0.023). CCK8 assays, colony formation assays and transwell assays indicated that miR-940 promoted the proliferation and invasion abilities of BC cells. The luciferase reporter assay suggested that miR-940 directly targeted FOXO3. Moreover, we found that the effect of si-FOXO3 was rescued by miR-940 inhibitors in BC cells. miR-940 may promote the proliferation and invasion abilities of BC cells by targeting FOXO3. Our study suggested that miR-940 could be a novel molecular target for therapies against BC.

MicroRNA-940 as a Potential Serum Biomarker for Prostate Cancer

Prostate cancer is one of the leading causes of death despite an astoundingly high survival rate for localized tumors. Though prostate specific antigen (PSA) test, performed in conjunction with digital rectal examinations, is reasonably accurate, there are major caveats requiring a thorough assessment of risks and benefits prior to conducting the test. MicroRNAs, a class of small non-coding RNAs, are stable molecules that can be detected in circulation by non-invasive methods and have gained importance in cancer prognosis and diagnosis in the recent years. Here, we investigate circulating miR-940, a miRNA known to play a role in prostate cancer progression, in both cell culture supernatants as well as patient serum and urine samples to determine the utility of miR-940 as a new molecular marker for prostate cancer detection. We found that miR-940 was significantly higher in serum from cancer patients, specifically those with clinically significant tumors (GS ≥ 7). Analysis of receiver operating characteristic curve demonstrated that miR-940 in combination with PSA had a higher area under curve value (AUC: 0.818) than the miR-940 alone (AUC: 0.75) for the diagnosis of prostate cancer. This study provides promising results suggesting the use of miR-940 for prostate cancer diagnosis.

LncRNA LINC02418 affects proliferation, migration, invasion, and apoptosis of hepatocellular carcinoma cells by regulating miR-940 expression

BACKGROUND

The long noncoding RNA (lncRNA) LINC02418 is up-regulated in non-small cell lung cancer, lung adenocarcinoma, colorectal cancer, and other tumors, and promotes the development of tumors. However, the role and mechanism of LINC02418 in the occurrence and development of liver cancer are unknown. Target gene prediction with LncBase Predicted v.2 shows that LINC02418 may target miR-940. This study hypothesized that LINC02418 can target and regulate miR-940 to affect the proliferation, migration, invasion, and apoptosis of liver cancer cells, thereby affecting the development of liver cancer.

AIM

To investigate the effect of lncRNA LINC02418 on the proliferation, migration, invasion, and apoptosis of hepatocellular carcinoma cells and the underlying mechanism.

METHODS

RT-qPCR was used to detect the expression levels of LINC02418 and miR-940 in hepatocellular carcinoma cancer tissues and adjacent tissues. After LINC02418 small interfering RNA or miR-940 mimic was transfected into liver cancer HCCLM3 cells, RT-qPCR was used to detect the transfection efficiency, and CCK-8 assay, Transwell assay, flow cytometry, and Western blot were used to detect the effects of LINC02418 down-regulation or miR-940 up-regulation on HCCLM3 cell viability, migration, invasion, and apoptosis, as well as the protein expression levels of CyclinD1, p21, MMP-2, MMP-9, Bcl-2, and Bax. The regulatory relationship between miR-940 and LINC02418 was verified by double luciferase reporter gene assay.

RESULTS

Compared with adjacent tissues, the expression of LINC02418 in hepatocellular carcinoma tissues increased (P < 0.05), while the expression of miR-940 decreased (P < 0.05). Down-regulating LINC02418 or up-regulating miR-940 reduced HCCLM3 cell viability, the number of migrating and invading cells, and the protein expression of CyclinD1, MMP-2, MMP-9, and Bcl-2 (P < 0.05), but increased apoptosis and the protein expression of p21 and Bax (P < 0.05). LINC02418 negatively regulated the expression of miR-940. Down-regulating miR-940 reversed the effects of down-regulating LINC02418 on the proliferation, migration, invasion, and apoptosis of HCCLM3 cells.

CONCLUSION

The expression of LINC02418 is elevated in liver cancer tissues, and down-regulating its expression may inhibit the malignant biological behavior of hepatocellular carcinoma cells by up-regulating miR-940, which could be used as a molecular target for liver cancer treatment.

Hsa_circ_0046263 Drives the Carcinogenesis and Metastasis of Non-Small Cell Lung Cancer Through the Promotion of NOVA2 by Absorbing Mir-940 as a Molecular Sponge

Background

Circular RNAs (circRNAs) have increasingly been investigated in different cancers due to their regulatory roles. In this study, hsa_circ_0046263 will be detailedly researched in non-small cell lung cancer (NSCLC).

Methods

The analyses of hsa_circ_0046263, microRNA-940 (miR-940), and neuro-oncological ventral antigen 2 (NOVA2) levels were administrated by quantitative real-time polymerase chain reaction (qRT-PCR). The proliferation detection was conducted using Cell Counting Kit-8 (CCK-8) and colony formation assays. Cell cycle and apoptosis were evaluated by flow cytometry. Transwell assay for migration and invasion was used to determine cell metastatic capacity. Overall protein levels were examined adopting Western blot. Target binding analysis was completed via dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. The effect of hsa_circ_0046263 on NSCLC in vivo was studied by xenograft model in mice.

Results

Hsa_circ_0046263 was overtly upregulated in NSCLC with important prognostic value. In vitro experiments indicated that hsa_circ_0046263 knockdown caused inhibitory effects on NSCLC cell proliferation, cell cycle, and metastasis but stimulative effect on apoptosis. Molecular mechanism analysis demonstrated that hsa_circ_0046263 served as a miR-940 sponge to act in the development of NSCLC. Moreover, miR-940 targeted NOVA2 and NOVA2 was regulated by hsa_circ_0046263/miR-940 axis. NOVA2 overexpression also neutralized the miR-940-mediated progression inhibition of NSCLC cells. In vivo assays suggested that hsa_circ_0046263 enhanced NSCLC tumorigenesis by targeting miR-940/NOVA2 axis.

Conclusion

Hsa_circ_0046263 was identified as a cancer-promoting factor in NSCLC via sponging miR-940 and upregulating NOVA2, which presented a clear mechanism of NSCLC occurrence and progression.

The Hsa_circ_0091579/miR-940/TACR1 Axis Regulates the Development of Hepatocellular Carcinoma

Purpose

Circular RNAs (circRNAs) play important roles in hepatocellular carcinoma (HCC) development. The circRNA hsa_circ_0091579 (circ_0091579) is dysregulated in HCC, while the mechanism of circ_0091579 in HCC development is largely unknown.

Patients and Methods

Thirty paired cancer and adjacent normal tissues were harvested from HCC patients. SNU-387 and Huh7 cells were cultured in this study. circ_0091579, microRNA-940 (miR-940) and tachykinin-1 receptor (TACR1) abundances were measured via quantitative reverse transcription-polymerase chain reaction or Western blot. Cell viability, migration, invasion, colony ability, cell cycle distribution and apoptosis were assessed via 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, transwell assay, colony formation assay and flow cytometry. The interaction among circ_0091579, miR-940 and TACR1 was tested via dual-luciferase reporter analysis. The anti-HCC role of circ_0091579 knockdown in vivo was investigated using xenograft model.

Results

circ_0091579 expression was enhanced in HCC tissue samples and cells. circ_0091579 silence inhibited cell viability, migration, invasion and colony formation, induced cell cycle arrest at G0/G1 phase, and promoted apoptosis in HCC cells. miR-940 was targeted via circ_0091579 and miR-940 knockdown reversed the suppressive effect of circ_0091579 silence on HCC development. miR-940 targeted TACR1 to repress HCC development. circ_0091579 could regulate TACR1 expression by mediating miR-940. Down-regulation of circ_0091579 decreased xenograft tumor growth.

Conclusion

Knockdown of circ_0091579 repressed HCC development by mediating miR-940/TACR1 axis, indicating a new pathogenesis of HCC.

Circ_0058124 Upregulates MAPK1 Expression to Promote Proliferation, Metastasis and Metabolic Abilities in Thyroid Cancer Through Sponging miR-940

Background

Thyroid cancer (TC) is an endocrine disease, and its progression is regulated by many factors, including circular RNAs (circRNAs). However, as a new circRNA, the role of circ_0058124 in TC is worth further exploration.

Methods

The expression levels of circ_0058124, microRNA-940 (miR-940) and mitogen-activated protein kinase 1 (MAPK1) were assessed by quantitative polymerase chain reaction (q-PCR). The circular characteristic of circ_0058124 was identified by oligo (dT)₁₈ primers, Ribonuclease R (RNase R) and Actinomycin D (ActD), and its localization was determined by nuclear-cytoplasmic separation assay. Also, cell proliferation was detected by colony formation assay, and cell migration and invasion were assessed by transwell assay. Further, Seahorse XF Extracellular Flux Analyzer was used to measure the oxygen consumption rate (OCR) of cells. Besides, dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull-down assays were used to identify the mechanism of circ_0058124. Western blot (WB) analysis was used to test the MAPK1 protein level. In addition, mice xenograft models were constructed to test the effect of circ_0058124 on TC tumor growth in vivo.

Results

Circ_0058124 was highly expressed in TC and is a stable cyclic transcript, mainly located in the cytoplasm. Circ_0058124 knockdown suppressed proliferation, migration, invasion and metabolic abilities in TC cells. MiR-940 could be absorbed by circ_0058124, and the inhibition effect of its overexpression on TC progression could be reversed by overexpressed-circ_0058124. MAPK1 was a target of miR-940, and the suppression effect of its silencing on TC progression could be inverted by miR-940 inhibitor. Besides, MAPK1 expression was regulated by circ_0058124 and miR-940. Interference of circ_0058124 also reduced TC tumor growth in vivo.

Conclusion

Circ_0058124 might play a carcinogenic role in TC progression by regulating the miR-940/MAPK1 axis, which might provide a new idea for the treatment of TC.

Downregulation of Hsa_circ_0000735 Inhibits the Proliferation, Migration, Invasion, and Glycolysis in Non-small-cell Lung Cancer by Targeting miR-940/BMPER Axis

BACKGROUND

Lung cancer is the most commonly diagnosed cancer and the major cause of cancer-related deaths worldwide. The increasing studies have demonstrated that circular RNA (circRNA) was involved in the progression of various cancers, including non-small-cell lung cancer (NSCLC). This study was designed to assess the expression, roles and functional mechanisms of circ_0000735 in NSCLC.

MATERIALS AND METHODS

The expression levels of circ_0000735, miR-940 and bone morphogenetic protein binding endothelial cell precursor-derived regulator (BMPER) were estimated by the real-time quantitative polymerase chain reaction (RT-qPCR). The biological behaviors of NSCLC cells such as proliferation, migration and invasion were analyzed by cell counting kit-8 (CCK-8), colony-forming assays and transwell assay, respectively. Furthermore, extracellular acid ratio and lactate production were tested to assess glycolysis levels of NSCLC cells. The interaction relationship among circ_0000735, BMPER and miR-940 was analyzed by bioinformatics database and dual-luciferase reporter assay. The protein expression level of BMPER was assessed by Western blot assay. Tumorigenesis assay was established to clarify the functional roles of circ_0000735 in vivo.

RESULTS

Circ_0000735 was upregulated and significantly correlated with overall survival in patients with NSCLC. In addition, the loss-of-functional experiments revealed that knockdown of circ_0000735 repressed proliferation, migration, invasion and glycolysis of NSCLC cells and tumor growth in vivo, which was overturned by overexpression of BMPER. Similarly, overexpression of circ_0000735 enhanced proliferation, migration, invasion, and glycolysis of NSCLC cells. In addition, we also confirmed that overexpression of miR-940 impeded proliferation, migration, invasion, and glycolysis of NSCLC cells. Furthermore, overexpression of BMPER abolished si-circ_0000735 induced effects on NSCLC cells.

CONCLUSION

Circ_0000735 regulated proliferation, migration, invasion, and glycolysis in NSCLC cells by targeting miR-940/BMPER axis.

MicroRNA-940 inhibits epithelial-mesenchymal transition of glioma cells via targeting ZEB2

MicroRNAs have been found ectopically expressed in many cancers and play essential roles in tumor EMT progress. Recent studies identified decreased miR-940 expression in glioma cells and may serve as a tumor-suppressor. However, whether miR-940 involve in glioma EMT remain poorly understood. Here we confirmed that miR-940 was significantly reduced in glioma cells and tissues. Introduction of miR-940 dramatically suppressed invasion and migration of glioma cells. Gain-of-function experiments showed ZEB2 as a direct target of miR-940, knockdown of ZEB2 evidently repressed invasive capacity of glioma cells through EMT. Moreover, reintroduction of ZEB2 effectively reversed the tumor suppressive effect of miR-940 treatment. In vivo study showed reduced tumor cell motion in miR-940-injected groups. Spearman's correlation analysis indicated inversely correlated expression of ZEB2 and miR-940 in gliomas and NBTs. Altogether, miR-940-ZEB2 cascade may play important roles in glioma cells invasion and EMT progression, and might provide new therapeutic approaches for better outcomes of GBM patients.

The better effects of microbubble ultrasound transfection of miR-940 on cell proliferation inhibition and apoptosis promotion in human cervical cancer cells

Purpose

Cervical cancer is the second leading cause of women’s cancer-related death. MiR-940 has been reported as a critical factor in various cancers. Based on the high transfection efficiency and low side effect, the clinical application of microbubble ultrasound contrast agent in gene treatment has attracted a widespread attention. In this study, we determined the mechanism of miR-940 inhibiting cell proliferation and cycle procession, and promoting cell apoptosis in cervical cancer Hela cells. In addition, we compared the effects of different transfection methods, including liposome, microbubble, ultrasound, and microbubble coupled with ultrasound.

Patients and methods

MTT assay, PI staining, and Annexin-Ⅴ/PI staining assays were, respectively, performed to evaluate cell proliferation status, cell cycle progression, and apoptosis status. RT-PCR and Western blot were conducted to measure the levels of cell cycle- and apoptosis-related factors, and the phosphorylation levels of PI3K and Akt.

Results

Results showed that the overexpression of miR-940 inhibited cell proliferation, blocked cell cycle, and promoted apoptosis by regulating cell cycle-related factors (such as inhibited Cyclin D1 and CDK4) and apoptosis-related factors (such as promoted Puma and Bax, inhibited Bcl-2 and Cleaved caspase9), and inhibiting the phosphorylation and activation of PI3K/AKT pathway. Among all of them, miR-940 transfected with microbubble and ultrasound showed the greatest changes.

Conclusion

It provides evidence that miR-940 could be a wonderful biomarker and treatment agent for cervical cancer, and microbubble ultrasound would have more wide application in the clinical treatment of cancers.

MicroRNA-940 inhibits glioma cells proliferation and cell cycle progression by targeting CKS1

Glioblastoma (GBM) is the most frequently occurred malignant human tumor that arise in brain with a poor prognosis. microRNAs (miRNAs) are vital small molecules during GBM initiation and progression. However, the expression of miR-940 and its potential function in GBM remain poor. Our study demonstrated that miR-940 was dramatically decreased in GBM cells and glioma tissues. Introduction of miR-940 significantly repressed proliferative ability of GBM cells. Notably, treatment of miR-940 dramatically suppressed tumor growth in an animal model, accompanied by decreased Ki67 expression. Functional experiments showed CKS1 as a target of miR-940, knockdown of CKS1 significantly induced the cell cycle arrest and restrained GBM cells proliferation, consistent with miR-940 treatment. Furthermore, reintroduction of CKS1 into glioma cells effectively rescued the tumor suppressive effect of miR-940. Correlation analysis indicated that miR-940 expression was inversely related to CKS1 mRNA levels in NBTs and gliomas. Together, miR-940/CKS1 signaling may be required for GBM progression and provide a new insight in diagnosis and prognosis of GBM patients.

miR-940 potentially promotes proliferation and metastasis of endometrial carcinoma through regulation of MRVI1

The specific functions and clinical significance of miR-940 in endometrial carcinoma (EC) have not been studied. First, we assessed the expression of miR-940 and MRVI1 in EC tissues collected from The Cancer Genome Atlas (TCGA) database and EC cell lines. miR-940 was significantly overexpressed in EC tissues and cell lines, particularly in RL95-2 cells. Correlation analysis showed that miR-940 expression level was remarkably associated with age, grade, and death. Moreover, the overall survival (OS) rate in the miR-940 low expression group was higher, compared with miR-940 high expression group. Univariate and multivariate models demonstrated that miR-940 expression, stage, and age were predictive indicators of OS. Moreover, there was no significance of the proliferation ability among the three EC cell lines (RL95-2, ISK, and KLE). To reveal the biological roles of miR-940, we respectively transfected RL95-2 cells with miR-940 mimics, miR-940 inhibitors, and control to further investigate the cell proliferation ability, and migration as well as invasion potential of RL95-2 cells. The transfection of miR-940 mimics significantly increased the proliferation and migration/invasion ability of RL95-2 cells. MRVI1 was predicted to be a potential target of miR-940 by means of in silico analysis followed by validation using luciferase reporter assays. MRVI1 was correlated with good prognosis. Moreover, forced expression of MRVI1 in miR-940 mimic transfected cells abolished the facilitation of miR-940 on cell proliferation, migration, and invasion of RL95-2 and KLE cells. In conclusion, our study demonstrates that miR-940 might function as a reliable diagnostic and prognostic signature in EC.

MiR-139-5p, miR-940 and miR-193a-5p inhibit the growth of hepatocellular carcinoma by targeting SPOCK1

The study was aimed to screen out miRNAs with differential expression in hepatocellular carcinoma (HCC), and to explore the influence of the expressions of these miRNAs and their target gene on HCC cell proliferation, invasion and apoptosis. MiRNAs with differential expression in HCC were screened out by microarray analysis. The common target gene of these miRNAs (miR‐139‐5p, miR‐940 and miR‐193a‐5p) was screened out by analysing the target genes profile (acquired from Targetscan) of the three miRNAs. Expression levels of miRNAs and SPOCK1 were determined by quantitative real time polymerase chain reaction (qRT‐PCR). The target relationships were verified by dual luciferase reporter gene assay and RNA pull‐down assay. Through 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide,thiazolyl blue tetrazolium bromide (MTT) and transwell assays and flow cytometry, HCC cell viability, invasion and apoptosis were determined. In vivo experiment was conducted in nude mice to investigate the influence of three miRNAs on tumour growth. Down‐regulation of miR‐139‐5p, miR‐940 and miR‐193a‐5p was found in HCC. Overexpression of these miRNAs suppressed HCC cell viability and invasion, promoted apoptosis and inhibited tumour growth. SPOCK1, the common target gene of miR‐139‐5p, miR‐940 and miR‐193a‐5p, was overexpressed in HCC. SPOCK1 overexpression promoted proliferation and invasion, and restrained apoptosis of HCC cells. MiR‐139‐5p, miR‐940 and miR‐193a‐5p inhibited HCC development through targeting SPOCK1.

MicroRNA-940 inhibits glioma progression by blocking mitochondrial folate metabolism through targeting of MTHFD2

The aggressiveness and recurrence of glioma are major obstacles for the treatment of this type of tumor. Further understanding of the molecular mechanisms of glioma is necessary to improve the efficacy of therapy. MicroRNAs have been widely studied in many human cancers. Here, we found that miR-940 was one of the primary downregulated miRNAs in clinical samples and glioma cell lines through bioinformatics analysis and qRT-PCR. Upregulating miR-940 expression significantly inhibited the proliferation and invasion and promoted apoptosis of U87 and U118 cells. In addition, experiments in vivo showed that upregulation of miR-940 expression inhibited xenograft growth. Methylenetetrahydrofolate dehydrogenase (MTHFD2), a dual-functional metabolic enzyme, is involved in the one-carbon metabolism of folate in mitochondria. We found MTHFD2 to be overexpressed in glioma tissues and our clinical samples by qRT-PCR and Western blot assays. Through TargetScan prediction and luciferase assays, we found that miR-940 directly targets MTHFD2. Upregulation of miR-940 expression inhibited the expression of MTHFD2 and led to intracellular one-carbon metabolism dysfunction. Furthermore, the antitumor effects of miR-940 could be attenuated by overexpression of MTHFD2. Together, the results of our study suggest that miR-940 may be a new therapeutic target for the treatment of glioma through targeting of MTHFD2.

Long noncoding RNA lncHERG promotes cell proliferation, migration and invasion in glioblastoma

Long noncoding RNAs have recently been proven to regulate tumorgenesis in many cancers. However, their biological functions in glioblastoma remain largely unknown. Here we found an uncharacteristic lncRNA lncHERG that is highly expressed in human glioblastoma (GBM). We found that lncHERG knockdown inhibited cell proliferation, migration and invasion in glioblastoma in vitro and in vivo. Moreover, the higher expression of lncHERG in patients with glioblastoma indicated lower survival rate and poorer prognosis. Mechanistically, we found that lncHERG can serve as a sponge for miR-940 which is a tumor suppressor in cervical cancer and whose function has not been defined in glioblastoma. We showed that miR-940 was down-regulated in glioblastoma tissues compared to peritumor tissues. LncHERG knockdown impaired cell proliferation, migration and invasion while inhibition of miR-940 in the meantime reversed this trend. In conclusion, our study highlights the essential role of lncHERG in glioblastoma by acting as a competing endogenous RNA of miR-940, which may serve as a new prognostic biomarker in glioblastoma.

Exosomal miR-940 maintains SRC-mediated oncogenic activity in cancer cells: a possible role for exosomal disposal of tumor suppressor miRNAs

Exosomes have emerged as important mediators of diverse biological functions including tumor suppression, tumor progression, invasion, immune escape and cell-to-cell communication, through the release of molecules such as mRNAs, miRNAs, and proteins. Here, we identified differentially expressed exosomal miRNAs between normal epithelial ovarian cell line and both resistant and sensitive ovarian cancer (OC) cell lines. We found miR-940 as abundant in exosomes from SKOV3-IP1, HeyA8, and HeyA8-MDR cells. The high expression of miR-940 is associated with better survival in patients with ovarian serous cystadenocarcinoma. Ectopic expression of miR-940 inhibited proliferation, colony formation, invasion, and migration and triggered G0/G1 cell cycle arrest and apoptosis in OC cells. Overexpression of miR-940 also inhibited tumor cell growth in vivo. We showed that proto-oncogene tyrosine-protein kinase (SRC) is directly targeted by miR-940 and that miR-940 inhibited SRC expression at mRNA and protein levels. Following this inhibition, the expression of proteins downstream of SRC, such as FAK, paxillin and Akt was also reduced. Collectively, our results suggest that OC cells secrete the tumor-suppressive miR-940 into the extracellular environment via exosomes, to maintain their invasiveness and tumorigenic phenotype.

Expressions of miRNAs in papillary thyroid carcinoma and their associations with the clinical characteristics of PTC

BACKGROUND

The sensitivity and specificity of biomarkers which have been used in clinical practice for diagnosis of papillary thyroid carcinoma (PTC) are low, it is essential to develop novel diagnostic and prognostic biomarkers for PTC.

OBJECTIVE

To explore the expressions of miR-940, miR-15a, miR-16 and IL-23 in PTC tissues and plasma and their associations with the clinical characteristics of PTC.

METHODS

We investigated the expressions of miR-940, miR-15a, miR-16 and IL-23 in plasma and thyroid tissues of PTC, nodular goiter and healthy people with qRT-PCR, and further analyzed the associations between their levels and the clinical characteristics of PTC.

RESULTS

Level of IL-23 expression was higher while levels of miR-940, miR-15a and miR-16 expression in the PTC tissues were lower compared with the nodular goiter tissues and perineoplastic thyroid tissues. And the levels of miR-940, miR-15a, miR-16 and IL-23 expression in the PTC tissues were associated with some clinical characteristics of PTC, including bilateral tumor, multicentricity, extrallyroidal invasion, cervical lymph node metastasis, distant metastasis and clinical advanced stages (III/IV).

CONCLUSIONS

Expressions of miR-940, miR-15a, miR-16 and IL-23 in PTC tissues might be useful biomarkers and promising targets in the diagnosis of papillary thyroid carcinoma.

Over-expression of microRNA-940 promotes cell proliferation by targeting GSK3β and sFRP1 in human pancreatic carcinoma

Increasing study reports that Wnt/β-catenin signaling pathway plays an essential role in numerous cancers growth, progression and metastasis. Aberrant miR-940 expression has been studied in gastric and breast cancer. However, the molecular mechanism of miR-940 enhancing proliferation and metastatic ability in human pancreatic carcinoma is far from to know. Real-time PCR was used to quantify miR-940 expression. Luciferase reporter assays here were performed to verify the activity of Wnt/β-catenin signaling pathway and targeting gene relationships, and immunofluorescence assay was applied to observe β-catenin expressed intensity. Bioinformatics analysis together with in vivo and vitro functional analysis indicated the potential targeting genes of miR-940. Specimens from 15 pairs of patients with human pancreatic carcinoma were involoved to confirm the relationship between miR-940 expression and the GSK3β/sFRP1 through real-time PCR and western blot assays. Bioinformatics combined with cell luciferase function researches determined the possible regulation of miR-940 on the 3'-UTR of the GSK3β and sFRP1 genes, resulting in the Wnt/β-catenin signaling activation. Further, miR-940 knockdown significantly recovered GSK3β and sFRP1 expression and relieved Wnt/β-catenin-mediated cell invasion, migration, metastasis and proliferation. The ectopic up-regulation of miR-940 significantly suppressed GSK3β/sFRP1 expression and promoted pancreatic carcinoma proliferation and invasion. Our study suggested mechanistic relationship between miR-940 and Wnt/β-catenin in the development and progression of pancreatic carcinoma through regulation of GSK3β and sFRP1.

MicroRNA-940 promotes tumor cell invasion and metastasis by downregulating ZNF24 in gastric cancer

Growing evidence indicates that microRNA (miRNA) plays a vital role in progression and metastasis of gastric cancer (GC). However, the underlying mechanism of miRNA-mediated metastasis has not been fully understood. Recently, miRNA-940 (miR-940) was found to be overexpressed in GC, which correlated with malignant progression and poor survival. Mechanistically, we found that miR-940 promoted GC cell migration, invasion, and metastasis in vivo by directly and functionally repressing the expression of Zinc Finger Transcription Factor 24 (ZNF24). Importantly, upregulation of ZNF24 could re-inhibit miR-940-induced migration and invasion. Hence, we demonstrated the oncogenic role of miR-940 in GC, finding that miR-940 promoted GC progression by directly downregulating ZNF24 expression, and targeting miR-940 could serve as a novel strategy for future GC therapy.

Plasma miR-940 may serve as a novel biomarker for gastric cancer

It was reported that circulating microRNAs could be applied as non-invasive biomarkers for cancer monitoring. The purpose of this study was to identify plasma miRNA that may serve as a novel biomarker for gastric cancer and to evaluate its clinical application. MicroRNA profiles were generated from plasma samples of 5 patients with gastric cancer (GC) versus 5 healthy controls (HC). MicroRNA-940 (miR-940) was one of the most downregulated miRNAs with fold change of 0.164. It was revealed that the expression of miR-940 was downregulated in both the initial set (N = 30, P < 0.0001) and the validation set (N = 80, P < 0.0001) of plasma samples of patients with gastric cancer. The sensitivity was obviously higher than the current biomarkers CEA and CA19-9 (81.25 % vs. 22.54 % and 15.71 %). MiR-940 was also significantly downregulated in gastric cancer tissue samples (N = 34, P = 0.0015), as well as in cancer cell lines (N = 7). Importantly, miR-940 was significantly highly expressed in stomach tissue samples than in other types of tissue samples including the liver, breast, thyroid, and lung. Moreover, there was a trend of lower expression of miR-940 from early to advanced stage of gastric cancer. Target prediction suggested that miR-940 regulated cell signaling including NF-κB and Wnt/β-catenin, as well as pathways of cell communication and adhesion. These pathways play critical roles in gastric cancer initiation and progression. It is the first report that miR-940 may mainly express in the stomach. Downregulation of plasma miR-940 may serve as a novel biomarker for detection of gastric cancer.

MiR-940 inhibits hepatocellular carcinoma growth and correlates with prognosis of hepatocellular carcinoma patients

Hepatocellular carcinoma (HCC) is among the leading causes of cancer-related death in China. Deregulation of microRNA (miRNA) contributes to HCC development by influencing cell growth, apoptosis, migration or invasion. It has been proved that miR-940 plays important roles in various cancers. Here we investigated the role of miR-940 in HCC. We found that miR-940 was remarkably decreased in HCC tissues and cell lines. Importantly, lower miR-940 expression in HCC tissues significantly correlated with the reduced patient's survival rate. Overexpression of miR-940 inhibited HCC cell line growth and induced cell apoptosis, and vice versa. Estrogen-related receptor gamma (ESRRG) was targeted by miR-940, and suppression of ESRRG inhibited HCC cell lines growth and induced cell apoptosis. In conclusion, we found that a lower level of miR-940 in HCC promoted cellular proliferation via ESRRG, which may lead to the short survival period of HCC patients.