miR-186-5p promotes cell growth, migration and invasion of lung adenocarcinoma by targeting PTEN

Identifying the driver miRNAs with somatic copy number alterations driving dysregulated ceRNA networks in cancers

BACKGROUND

MicroRNAs (miRNAs) play critical roles in cancer initiation and progression, which were critical components to maintain the dynamic balance of competing endogenous RNA (ceRNA) networks. Somatic copy number alterations (SCNAs) in the cancer genome could disturb the transcriptome level of miRNA to deregulate this balance. However, the driving effects of SCNAs of miRNAs were insufficiently understood.

METHODS

In this study, we proposed a method to dissect the functional roles of miRNAs under different copy number states and identify driver miRNAs by integrating miRNA SCNAs profile, miRNA-target relationships and expression profiles of miRNA, mRNA and lncRNA.

RESULTS

Applying our method to 813 TCGA breast cancer (BRCA) samples, we identified 29 driver miRNAs whose SCNAs significantly and concordantly regulated their own expression levels and further inversely dysregulated expression levels of their targets or disturbed the miRNA-target networks they directly involved. Based on miRNA-target networks, we further constructed dynamic ceRNA networks driven by driver SCNAs of miRNAs and identified three different patterns of SCNA interference in the miRNA-mediated dynamic ceRNA networks. Survival analysis of driver miRNAs showed that high-level amplifications of four driver miRNAs (including has-miR-30d-3p, has-mir-30b-5p, has-miR-30d-5p and has-miR-151a-3p) in 8q24 characterized a new BRCA subtype with poor prognosis and contributed to the dysfunction of cancer-associated hallmarks in a complementary way. The SCNAs of driver miRNAs across different cancer types contributed to the cancer development by dysregulating different components of the same cancer hallmarks, suggesting the cancer specificity of driver miRNA.

CONCLUSIONS

These results demonstrate the efficacy of our method in identifying driver miRNAs and elucidating their functional roles driven by endogenous SCNAs, which is useful for interpreting cancer genomes and pathogenic mechanisms.

Hsa_circ_0119412 Contributes to Development of Retinoblastoma by Targeting miR-186-5p/ELK4 Axis

Increasing evidences indicate the crucial role of circRNAs in tumorigenesis, but little is understood about their molecular mechanism in retinoblastoma (RB). This paper was designed for exploring the circ_0119412 function in cases with RB and the potential mechanism. RT-qPCR was utilized to ascertain circ_0119412 and miR-186-5p levels in RB tissues and cells, and western blotting was used to quantify ELK4 in RB cells. In addition, CCK-8 and scratch assays were carried out for evaluation of cell proliferation and migration, respectively. Apoptosis-related proteins levels (Bax and Bcl-2) were measure by western blotting. Tumor growth in vivo was detected utilizing xenograft tumor experiment. The targeting relationship between circ_0119412, miR-186-5p, and ELK4 was validated using a dual-luciferase reporter assay and an RNA immunoprecipitation (RIP) assay. In RB tissues and cells, Circ_0119412 and ELK4 expression were upregulated, while miR-186-5p expression was downregulated. In vitro assay revealed that downregulating circ_0119412 accelerated the cell apoptosis of RB cells and slowed down their migration and proliferation, and the in vivo assay indicated that circ_0119412 downregulation reduced the weight and volume of tumor in nude mice. In addition, miR-186-5p interference promoted the malignant behavior of RB cells, while ELK4 silencing showed an opposite trend. Mechanically, circ_0119412 can promote RB malignant phenotypes via miR-186-5p/ELK4 axis. Circ_0119412 was found to be upregulated in RB, and could accelerate the progression of RB via the miR-186-5p/ELK4 axis, indicating circ_0119412 may serve a promising clinical therapeutic target of RB.

Hsa_circ_0005085 may suppress cutaneous squamous cell carcinoma growth and metastasis through targeting the miR-186-5p/LAMC1 axis

BACKGROUND

Cutaneous squamous cell carcinoma (CSCC) is a severe malignancy derived from the skin. Mounting evidence suggests that circular RNAs (circRNAs) participate in diverse biological functions in human cancers, containing CSCC. However, the biological functions and underlying mechanism of hsa_circ_0005085 in CSCC have not been clearly studied.

METHODS

Expression levels of hsa_circ_0005085, microRNA-186-5p (miR-186-5p), and Laminin subunit gamma 1 (LAMC1) were detected by reverse transcription-quantitative polymerase chain reaction. Cell counting kit-8 assay, colony formation assay, and 5-Ethynyl-2'-deoxyuridine assay were used to assess cell proliferation. Transwell assay was conducted to detect cell migration and invasion. Cell apoptosis was analyzed by flow cytometry. Protein expression of LAMC1, E-cadherin, Snail, and slug were assessed using western blot assay. Using bioinformatics software, the binding between miR-186-5p and hsa_circ_0005085 or LAMC1 was predicted, followed by verification using a dual-luciferase reporter and RNA-Immunoprecipitation. The mouse xenograft model was established to investigate the role of hsa_circ_0005085 in vivo.

RESULTS

Hsa_circ_0005085 level was downregulated in CSCC tissues and cells. Overexpression of hsa_circ_0005085 inhibited cell proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), and promoted cell apoptosis in CSCC. MiR-186-5p could restore the effect of hsa_circ_0005085 overexpression on CSCC cells, and the knockdown of LAMC1 reversed the regulation of the miR-186-5p inhibitor. In mechanism, hsa_circ_0005085 served as a sponge for miR-186-5p to regulate LAMC1 expression. Overexpression of hsa_circ_0005085 reduced growth of tumor via miR-186-5p/LAMC1 axis in vivo.

CONCLUSION

In our study, hsa_circ_0005085 might inhibit CSCC development by targeting the miR-186-5p/LAMC1 axis, which might provide a promising therapeutic target for CSCC.

Risk factors and actionable molecular signatures in COVID-19-associated lung adenocarcinoma and lung squamous cell carcinoma patients

The molecular mechanism of COVID-19's pathogenic effect on lung cancer patients is yet unknown. In this study, we used differential gene expression pattern analysis to try to figure out the possible disease mechanism of COVID-19 and its associated risk factors in patients with the two most common types of non-small-cell lung cancer, lung adenocarcinoma and lung squamous cell carcinoma. We also used network-based approaches to identify potential diagnostic and molecular targets for COVID-19-infected lung cancer patients. Our study showed that lung cancer and COVID-19 patients share 36 genes that are expressed differently and in common. Most of these genes are expressed in lung tissues and are mostly involved in the pathogenesis of different respiratory tract diseases. Additionally, we also found that COVID-19 may affect the expression of several cancer-associated genes in lung cancer patients, such as the oncogenes JUN, TNC, and POU2AF1. Moreover, we also reported that COVID-19 may predispose lung cancer patients to other diseases like acute liver failure and respiratory distress syndrome. Also, our findings in concert with published literature suggest that molecular signatures like hsa-mir-93-5p, CCNB2, IRF1, CD163, and different immune cell-based approaches could help both diagnose and treat this group of patients. Overall, the scientific results of this research will aid in the formulation of suitable management strategies as well as the development of diagnostic and therapeutic methods for COVID-19-infected lung cancer patients.

SNHG1/miR-186/FUT8 regulates cell migration and invasion in oral squamous cell carcinoma

Recently, lncRNAs are associated with the progression and development of various cancers. We aimed to explore the effects of lncRNA SNHG1 on the proliferation, apoptosis, migration, and invasion of oral squamous cell carcinoma (OSCC) cells. Quantitative real-time PCR (RT-qPCR) was used for measurement of SNHG1 in OSCC cells. Cell proliferation, apoptosis, migration, and invasion were detected by CCK-8 assay, flow cytometry, Cell Death Detection ELISA PLUS kit, and transwell assays. Dual-luciferase reporter assay and RNA-binding protein immunoprecipitation (RIP) assay were used to clarify the relationship between SNHG1 and miR-186. SNHG1 was overexpressed in OSCC cells. SNHG1 silencing prevented cell proliferation and increased the incidence of apoptosis, DNA fragments, cleaved-caspase 3, and Bax protein levels. Cell migration and invasion were reduced after SNHG1 deletion, and MMP2 and MMP9 protein levels were decreased. SNHG1 overexpression promoted cell survival, migration, and invasion, reduced DNA fragments formation. Mechanistically, we demonstrated that SNHG1 could directly bind to miR-186 and positively regulated α1, 6-fucosyltransferase (FUT8) level. Functional investigation showed that miR-186 depletion reversed the roles of SNHG1 silencing in cell proliferation, apoptosis, and migration. Taken together, our findings illuminated that SNHG1 regulated cell proliferation, migration, and invasion by sponging miR-186 to depress FUT8 expression.

LncRNA NUTM2A-AS1 aggravates the progression of hepatocellular carcinoma by activating the miR-186-5p/KLF7-mediated Wnt/beta-catenin pathway

Emerging evidence has uncovered that noncoding RNAs (ncRNAs) contribute to the development of hepatocellular carcinoma (HCC). Nevertheless, the functions of the majority of long ncRNAs (lncRNAs) in HCC are unknown. Here, we intend to probe the function of lncRNA NUTM2A-AS1 in the evolvement of HCC and the related mechanism. Expression levels of lncRNA NUTM2A-AS1, miR-186-5p and KLF7 mRNA in HCC tissues and adjacent non-tumor tissues were monitored. Gain- or loss-of-function assays were utilized to investigate the biological functions of lncRNA NUTM2A-AS1, miR-186-5p and KLF7 in HCC cell lines (including HCCLM3 and Huh7). Western blot was implemented for the detection of the epithelial-mesenchymal transition (EMT)-related proteins (including E-cadherin, Vimentin and Snail), KLF7, Wnt, β-catenin, and stemness-related proteins (Nanog, OCT4, YKL40, and CD133). Furthermore, the targeted associations between lncRNA NUTM2A-AS1, miR-186-5p, and KLF7 were verified by bioinformatics analysis, dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. As a result, lncRNA NUTM2A-AS1 and KLF7 profiles were heightened in the HCC tissues versus adjacent normal tissues, while miR-186-5p had the opposite expression tendency. Up-regulation of lncRNA NUTM2A-AS1 was related to tumor size, advanced tumor stage, and lymph node metastasis of HCC patients. Functionally, overexpression of lncRNA NUTM2A-AS1 heightened HCC cells' growth, invasion, EMT, and stemness and repressed their apoptosis by activating the Wnt/β-catenin pathway. In contrast, up-regulation of miR-186-5p or inhibition of KLF7 had reverse effects. In vivo, lncRNA NUTM2A-AS1 overexpression facilitated tumor growth and EMT, accompanied by declined miR-186-5p levels and enhanced KLF7 expression. The mechanistic studies revealed that miR-186-5p served as a common target of lncRNA NUTM2A-AS1 and KLF7. As hinted by the rescue experiments, NUTM2A-AS1 partly abated miR-186-5p-mediated anti-tumor effects in HCC cells, whereas KLF7 knockdown reversed the promotive effects of NUTM2A-AS1. LncRNA NUTM2A-AS1 accelerated the evolution of HCC by up-regulating the KLF7/Wnt/beta-catenin pathway through sponging miR-186-5p.

Long noncoding RNA WT1-AS regulates trophoblast proliferation, migration, and invasion via the microRNA-186-5p/CADM2 axis

This study aimed to determine the role of long noncoding RNA (lncRNA) WT1 antisense RNA (WT1-AS) in the occurrence and progression of preeclampsia (PE) and to determine the underlying molecular mechanisms. The associations between WT1-AS and microRNA (miR)-186-5p, and miR-186-5p and cell adhesion molecule 2 (CADM2) were predicted using StarBase software and verified via dual-luciferase assays. To explore the role of the human chorionic trophoblast line HTR-8/SVneo, gene (WT1-AS/miR-186-5p) gain/loss of function experiments were performed. Qualitative reverse transcription-polymerase chain reaction (RT-PCR) analysis was used to evaluate transfection efficiency. Cell proliferation, apoptosis, cell migration, and invasion were assessed using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), flow cytometry, and transwell analysis, respectively. Moreover, CADM2 protein expression was measured by western blotting. The results indicated that overexpression of WT1-AS inhibited cell viability, migration, and invasion, and induced apoptosis in HTR-8/SVneo cells. We observed that miR-186a-5p directly targeted WT1-AS, and miR-186a-5p knockdown reversed the effects of WT1-AS knockdown in HTR-8/SVneo cells. Binding sites were found between miR-186-5p and CADM2, and CADM2-overexpression reversed the influence of miR-186-5p mimic on HTR-8/SVneo cells. In summary, our findings demonstrated that lncRNA WT1-AS participates in PE by regulating the proliferation and invasion of placental trophoblasts, through the miR-186-5p/CADM2 axis.

miR-221-5p and miR-186-5p Are the Critical Bladder Cancer Derived Exosomal miRNAs in Natural Killer Cell Dysfunction

Bladder cancer (BC) is the tenth most commonly diagnosed cancer worldwide, and its carcinogenesis mechanism has not been fully elucidated. BC is able to induce natural killer (NK) cell dysfunction and escape immune surveillance. The present study found that exosomes derived from the urinary bladder cancer cell line (T24 cell) contribute in generating NK cell dysfunction by impairing viability, and inhibiting the cytotoxicity of the NK cell on target cells. Meanwhile, T24 cell-derived exosomes inhibited the expression of the important functional receptors NKG2D, NKp30, and CD226 on NK cells as well as the secretion of perforin and granzyme-B. The critical miRNAs with high expression in T24 cell-derived exosomes were identified using high-throughput sequencing. Furthermore, following dual-luciferase reporter assay and transfection experiments, miR-221-5p and miR-186-5p were confirmed as interfering with the stability of the mRNAs of DAP10, CD96, and the perforin gene in NK cells and may be potential targets used in the therapy for BC.

METTL3/LINC00662/miR-186-5p feedback loop regulates docetaxel resistance in triple negative breast cancer

Insight into the mechanism of docetaxel resistance in breast cancer may help to improve prognosis. We aimed to investigate the role of N6-methyladenosine (m6A) and the METTL3/LINC00662/miR-186-5p pathway in regulating docetaxel resistance in triple negative breast cancer (TNBC). We have recruited 193 pathologically diagnosed TNBC patients from 2016 to 2017 in our hospital. Quantitative real-time PCR was used to evaluate the expression of LINC00662 and miR-186-5p both in vivo and in vitro. CCK8 tests were used to assess cell viability. ELISA was used for protein expression evaluation. Dual luciferase reporter gene assay and RNA pull-down were used to evaluate the interaction between LINC00662 and miR-186-5p. m6A levels were enhanced in breast cancer tissues and cells. LINC00662, miR-186-5p and METTL3 were differentially expressed in vivo, and METTL3 expression was associated with LINC00662 and miR-186-5p expression. LINC00662 and miR-186-5p were differentially expressed in vitro; LINC00662 promoted cell viability and decreased the apoptosis rate, whereas miR-186-5p inhibited cell viability and increased the apoptosis rate. Furthermore, we found that METTL3 regulated m6A levels in docetaxel-resistant breast cancer cells by regulating the expression of LINC00662. Moreover, LINC00662 and miR-186-5p regulated the cell viability rate of docetaxel-resistant breast cancer cells. Further experiments showed that LINC00662 directly interacted with miR-186-5p to exert biological functions; besides miR-186-5p could regulate the expression of METTL3. METTL3 promotes m6A levels and docetaxel resistance in breast cancer by regulating the expression of LINC00662 and miR-186-5p; more experiments are needed to clarify the role of m6A regulation in drug resistance.

MiR-96-5p Facilitates Lung Adenocarcinoma Cell Phenotypes by Inhibiting FHL1

Objective

FHL1 is understood as a tumor repressor gene in various cancers and a possible target for cancer treatment. We investigated the influences of FHL1 on cell functions as well as its molecular mechanisms in lung adenocarcinoma (LUAD) cells.

Methods

The miRNA-mRNA modulatory axis was predicted by bioinformatics. The expression levels of FHL1 mRNA and protein in LUAD cells were, respectively, analyzed by qRT-PCR and western blot. Dual luciferase analysis was introduced to verify the interaction between miR-96-5p and FHL1. CCK-8, cell colony formation, and Transwell assays were utilized to analyze proliferation, colony formation, migration, and invasion of A549 cells.

Results

Expression of FHL1 mRNA and protein in LUAD tissue and cells was downregulated, which was linked with poor prognoses of patients. In addition, FHL1 overexpression could hamper colony formation, proliferation, invasion, and migration of LUAD cells. In addition, dual-luciferase analysis verified miR-96-5p as an upstream regulator of FHL1. Overexpression of miR-96-5p suppressed FHL1 expression in LUAD cells and promoted proliferation, invasion, and migration of LUAD cells, while overexpression of FHL1 could simultaneously restore the above-mentioned promoting effect.

Conclusion

MiR-96-5p fostered cell malignant behaviors by targeting FHL1. This research uncovered the regulatory mechanism of FHL1 in LUAD and offered optional therapeutic targets for LUAD patients.

Circ_ROBO2/miR-186-5p/TRIM14 axis regulates oxidized low-density lipoprotein-induced cardiac microvascular endothelial cell injury

Background

Coronary artery disease (CAD) is one of the main risks of death, which is mainly caused by coronary arteries arteriosclerosis. Circular RNAs (circRNAs) have shown important regulatory roles in cardiovascular diseases. We amid to explore the role of circ_ROBO2 in CAD.

Methods

Cardiac microvascular endothelial cells (CMECs) stimulated by oxidized low-density lipoprotein (ox-LDL) were served as the cellular model of CAD. Real-time quantitative polymerase chain reaction (RT-qPCR) and western blot assay were performed to detect RNA levels and protein levels, respectively. Cell proliferation was assessed by 5-ethynyl-2′-deoxyuridine (EdU) assay and Cell Counting Kit-8 (CCK-8) assay. Flow cytometry was employed for measuring cell apoptosis. Matrigel tube formation assay was used to evaluate angiogenesis ability. The intermolecular interaction was predicted by bioinformatics analysis and verified by dual-luciferase reporter and RNA-pull down assays.

Results

The expression of circ_ROBO2 was upregulated in CAD patients and ox-LDL-induced CMECs. Treatment of ox-LDL suppressed cell proliferation and angiogenic ability as well as promoted the apoptosis of CMECs partly by upregulating circ_ROBO2. MicroRNA-186-5p (miR-186-5p) was identified as a target of circ_ROBO2, and circ_ROBO2 knockdown attenuated ox-LDL-induced damage in CMECs by sponging miR-186-5p. Tripartite motif containing 14 (TRIM14) acted as a target of miR-186-5p, and TRIM14 overexpression alleviated miR-186-5p-mediated inhibitory effect on ox-LDL-induced injury in CMECs. Circ_ROBO2 positively regulated TRIM14 expression by sponging miR-186-5p.

Conclusion

Circ_ROBO2 played a promoting role in ox-LDL-induced CMECs injury by sponging miR-186-5p and regulating TRIM14, providing a promising treatment strategy for CAD.

Circular RNA (circ)_0129047 upregulates bone morphogenetic protein receptor type 2 expression to inhibit lung adenocarcinoma progression by sponging microRNA (miR)-1206

Circular RNAs (circRNAs) play significant roles in the tumorigenesis and progression of various cancers, including lung adenocarcinoma (LAC). However, their underlying biological functions in LAC remain unclear. Here, we investigated the tumor suppressor role of the newly identified circRNA, circ_0129047, in LAC tumorigenesis and progression. The expression levels of circ_0129047, microRNA (miR)-1206, and bone morphogenetic protein receptor type 2 (BMPR2) mRNA in LAC cells and tissues were monitored using reverse transcription-quantitative polymerase chain reaction. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays were used to confirm the targeting relationships among circ_0129047, miR-1206, and BMPR2 mRNA. Functional experiments for A549 and PC9 cells were performed using cell counting kit-8, bromodeoxyuridine enzyme-linked immunosorbent, caspase-3 activity, cell adhesion, wound healing, and transwell assays. Circ_0129047 expression levels were reduced in LAC cells and tissues. Mechanistically, we discovered that circ_0129047 could sponge miR-1206, and miR-1206 could directly target BMPR2. In addition, circ_0129047 or BMPR2 knockdown facilitated the viability, proliferation, adhesion, migration, and invasion, while inhibiting the apoptosis of LAC cells. Furthermore, the inhibitory effects of circ_0129047 or BMPR2 overexpression on the malignant phenotype of LAC cells could be reversed by the overexpression of miR-1206. In conclusion, circ _0129047 was found to play a tumor suppressive role in LAC progression; it upregulated BMPR2 expression to inhibit LAC progression by sponging miR-1206.

Abbreviations: non-small cell lung cancer (NSCLC); small cell lung cancer (SCLC); lung adenocarcinoma (LAC); Circular RNA (circRNA); MicroRNA (miRNA); bone morphogenetic protein (BMP); squamous cell lung cancer (SCC); RNA immunoprecipitation (RIP)

MiR-30a-3p Suppresses the Growth and Development of Lung Adenocarcinoma Cells Through Modulating GOLM1/JAK-STAT Signaling

A considerable amount of people succumbs to lung adenocarcinoma (LUAD) due to its high incidence and mortality. This study attempted to reveal the impacts of GOLM1 on LUAD. This work analyzed GOLM1 expression in LUAD and normal tissue and studied its prognostic value utilizing data from The Cancer Genome Atlas. RNA and protein levels were, respectively, determined utilizing qRT-PCR and western blot. Cell-aggressive behaviors were assessed employing Cell Counting Kit-8, scratch healing, and Transwell assays. The targetting relationship between GOLM1 and miR-30a-3p was assayed by dual-luciferase method. GOLM1 up-regulation in LUAD was found in TCGA and it was also a negative factor for survival in patients. GOLM1 overexpression promoted cell progression in LUAD. Down-regulated miR-30a-3p in LUAD was an upstream regulatory miRNA of GOLM1 in terms of molecular mechanism. Further, rescue assays illustrated that miR-30a-3p overexpression attenuated the GOLM1 facilitating impacts on LUAD progression. Finally, we proved that miR-30a-3p/GOLM1 regulated progression of LUAD cells via JAK-STAT pathway. Collectively, the inhibitory impacts of miR-30a-3p on LUAD growth may be mediated by GOLM1/JAK-STAT, which may contribute to the diagnosis of LUAD therapy and the development of therapeutic tools.

FTX Attenuates Cerebral Ischemia-Reperfusion Injury by Inhibiting Apoptosis and Oxidative Stress via miR-186-5p/MDM4 Pathway

LncRNA five prime to Xist (FTX) has been identified to exert a protective effect in multiple diseases. However, whether and how FTX attenuates cerebral ischemia-reperfusion injury (CI/RI) is still unclear. To simulate CI/RI, an in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) HT22 cell model and an in vivo middle cerebral artery occlusion/reperfusion (MCAO/R) Sprague-Dawley rat model were respectively constructed. In CI/RI plasma samples, OGD/R-challenged HT22 cells, and brain tissues from MCAO/R rats, FTX and mouse double minute 4 (MDM4) expressions were substantially decreased while miR-186-5p abundance was evidently increased. It was also revealed that FTX obviously improved neuronal damage induced by OGD/R through increasing proliferation, reducing apoptosis, and alleviating oxidative stress in OGD/R-challenged HT22 cells. Additionally, FTX positively regulated MDM4 level in OGD/R-treated HT22 cells as a sponge of miR-186-5p. Moreover, miR-186-5p upregulation or MDM4 suppression restored the inhibitory effects of FTX upregulation on OGD/R-triggered neuronal damage in HT22 cells. Therefore, these results suggest that FTX might ameliorate CI/RI by regulating the miR-186-5p/MDM4 pathway, providing a new target for stroke impairment treatment.

Using biological information to analyze potential miRNA-mRNA regulatory networks in the plasma of patients with non-small cell lung cancer

Background

Lung cancer is the most common malignant tumor, and it has a high mortality rate. However, the study of miRNA-mRNA regulatory networks in the plasma of patients with non-small cell lung cancer (NSCLC) is insufficient. Therefore, this study explored the differential expression of mRNA and miRNA in the plasma of NSCLC patients.

Methods

The Gene Expression Omnibus (GEO) database was used to download microarray datasets, and the differentially expressed miRNAs (DEMs) were analyzed. We predicted transcription factors and target genes of the DEMs by using FunRich software and the TargetScanHuman database, respectively. The Database for Annotation, Visualization, and Integrated Discovery (DAVID) was used for GO annotation and KEGG enrichment analysis of downstream target genes. We constructed protein-protein interaction (PPI) and DEM-hub gene networks using the STRING database and Cytoscape software. The GSE20189 dataset was used to screen out the key hub gene. Using The Cancer Genome Atlas (TCGA) and UALCAN databases to analyze the expression and prognosis of the key hub gene and DEMs. Then, GSE17681 and GSE137140 datasets were used to validate DEMs expression. Finally, the receiver operating characteristic (ROC) curve was used to verify the ability of the DEMs to distinguish lung cancer patients from healthy patients.

Results

Four upregulated candidate DEMs (hsa-miR199a-5p, hsa-miR-186-5p, hsa-miR-328-3p, and hsa-let-7d-3p) were screened from 3 databases, and 6 upstream transcription factors and 2253 downstream target genes were predicted. These genes were mainly enriched in cancer pathways and PI3k-Akt pathways. Among the top 30 hub genes, the expression of KLHL3 was consistent with the GSE20189 dataset. Except for let-7d-3p, the expression of other DEMs and KLHL3 in tissues were consistent with those in plasma. LUSC patients with high let-7d-3p expression had poor overall survival rates (OS). External validation demonstrated that the expression of hsa-miR-199a-5p and hsa-miR-186-5p in peripheral blood of NSCLC patients was higher than the healthy controls. The ROC curve confirmed that the DEMs could better distinguish lung cancer patients from healthy people.

Conclusion

The results showed that miR-199a-5p and miR-186-5p may be noninvasive diagnostic biomarkers for NSCLC patients. MiR-199a-5p-KLHL3 may be involved in the occurrence and development of NSCLC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09281-1.

MiR-186 Suppressed Growth, Migration, and Invasion of Lung Adenocarcinoma Cells via Targeting Dicer1

Objective

Globally, the fatal form of lung cancer is non-small-cell lung cancer (NSCLC), and its most common subtype is lung adenocarcinoma (LUAD). In cancer development and progression, miRNAs play key roles primarily in interacting with cancer-related genes. The main focus of this research was to examine the biological roles of miR-186 in LUAD.

Methods

We examined tissues of LUAD and lung cancer cell lines. The expressions of miR-186, Dicer1, Ki-67, and PCNA were determined by immunohistochemistry (IHC), real-time quantitative PCR (RT-PCR), and western blot assays. The CCK-8 and transwell assays were used to determine cell proliferation, migration, and invasion. To determine the association between miR-186 and Dicer1, a luciferase assay was used.

Results

MiR-186 expression was found to be lower in LUAD tissues, and this was correlated to TNM stage and lymph node metastasis in LUAD patients. miR-186 upregulation significantly reduced the proliferation rate and the level of Ki67 and PCNA of LUAD cell lines HCC827 and A549. Transwell assay exhibited that miR-186 upregulation considerably reduced HCC827 and A549 cells' migration and invasion abilities. Furthermore, we also confirmed that Dicer1 was a direct target of miR-186. Importantly, Dicer1 overexpression abolished the suppression of miR-186 mimics on cell proliferation, migration, and invasion of HCC827 and A549 cells.

Conclusion

These results indicated that the miR-186/Dicer1 pathway is critical for regulating LUAD cell proliferation, migration, and invasion.

Expression Profiling of microRNA From Peripheral Blood of Dairy Cows in Response to Staphylococcus aureus-Infected Mastitis

As the main pathogen causing dairy cow mastitis, Staphylococcus aureus can cause subclinical mastitis, which is difficult to be diagnosed. It seriously affects milk quality and the economic benefits of the dairy industry. Therefore, it is very necessary to find biomarkers for early diagnosis of S. aureus-infected mastitis in peripheral blood of dairy cows. In this study, S. aureus was used to infect the mammary gland tissues of dairy cows, and a mastitis model was successfully constructed. The RNAseq technology was used to determine the expression profiles of microRNA (miRNA) from peripheral blood of dairy cows infected with S. aureus at 0, 1, 3, 5, and 7 days. A total of 288 differentially expressed miRNAs (DIE-miRNAs) were found, of which 108 were known miRNAs and 180 were novel predicted miRNAs. Bioinformatics analysis results showed that the above DIE-miRNAs might be involved in 10 immune system-related signaling pathways (i.e., chemokine signaling pathway, leukocyte transendothelial migration, natural killer cell-mediated cytotoxicity, toll-like receptor signaling pathway, Jak-STAT signaling pathway, MAPK signaling pathway, Wnt signaling pathway, cell adhesion molecules, cytokine-cytokine receptor interaction, and ECM-receptor interaction), thus regulating the process of S. aureus mastitis. It was also found that the expression variation of up-regulated expression of miR-320a, miR-19a, and miR-19b as well as down-regulated expression of miR-143, miR-205, and miR-24 reached a significant level on the 5th and 7th day of infection, suggesting that they might play an important biological role in mastitis and provide a direction for the research and development of molecular therapy technology for mastitis. However, at different times after S. aureus infection, miR-1301 was significantly up-regulated in peripheral blood. miR-2284r was significantly down-regulated, suggesting that these two miRNAs might be the new blood biomarkers for S. aureus-infected dairy cow mastitis. The above results laid a new foundation for the research and development of molecular diagnosis and biological therapy technology for S. aureus-infected mastitis in dairy cow.

Chronic and Intermittent Hyperglycemia Modulates Expression of Key Molecules of PI3K/AKT Pathway in Differentiating Human Visceral Adipocytes

Background: Due to its prominence in the regulation of metabolism and inflammation, adipose tissue is a major target to investigate alterations in insulin action. This hormone activates PI3K/AKT pathway which is essential for glucose homeostasis, cell differentiation, and proliferation in insulin-sensitive tissues, like adipose tissue. The aim of this work was to evaluate the impact of chronic and intermittent high glucose on the expression of biomolecules of insulin signaling pathway during the differentiation and maturation of human visceral preadipocytes. Methods: Human visceral preadipocytes (HPA-V) cells were treated with high glucose (30 mM)during the proliferation and/or differentiation and/or maturation stage. The level of mRNA (by Real-Time PCR) and protein (by Elisa tests) expression of IRS1, PI3K, PTEN, AKT2, and GLUT4 was examined after each culture stage. Furthermore, we investigated whether miR-29a-3p, miR-143-3p, miR-152-3p, miR-186-5p, miR-370-3p, and miR-374b-5p may affect the expression of biomolecules of the insulin signaling pathway. Results: Both chronic and intermittent hyperglycemia affects insulin signaling in visceral pre/adipocytes by upregulation of analyzed PI3K/AKT pathway molecules. Both mRNA and protein expression level is more dependent on stage-specific events than the length of the period of high glucose exposure. What is more, miRs expression changes seem to be involved in PI3K/AKT expression regulation in response to hyperglycemic stimulation.

Overexpressed Hsa_circ_0001326 Contributes to the Decreased Cell Viability in SWAN71 Cells by Regulating MiR-186-5p/p27 Kip1 Axis

Preeclampsia (PE) is a severe pregnancy-specific complication responsible for a majority of maternal and fetal mortality. The dysfunction of trophoblast cells is known to be associated with the etiology of PE. Moreover, elevated expression of hsa_circ_0001326 was found in patients with PE without elucidating specific mechanisms. Thus, this study aimed to investigate the role of hsa_circ_0001326 in the dysfunction of trophoblast cells in vitro. Human trophoblast SWAN71 cells were used in this study. Cell proliferation, apoptosis and cell cycle were detected by 5-ethynyl-2'-deoxyuridine (EdU) staining, cell counting kit-8 assay, Annexin V/propidium iodide (PI) staining and flow cytometry, respectively. Dual luciferase assay was performed to validate the predicted targets. Additionally, Western blot was conducted for protein detection. The results indicated overexpression (OE) of hsa_circ_0001326 remarkably decreased the viability and proliferation of SWAN71 cells. MiR-186-5p was identified as the target of hsa_circ_0001326. Meanwhile, p27 Kip1 was validated as the target of hsa_miR-186-5p. Moreover, the increased apoptosis and decreased migration induced by hsa_circ_0001326 OE were inhibited by p27 Kip1 knockdown. Hsa_circ_0001326 OE upregulated p27 Kip1 and cleaved caspase3 and downregulated CDK2 and cyclin E1 in cells, while these phenomena were reversed by p27 Kip1 knockdown. In addition, hsa_circ_0001326 OE induced G0/G1 cell cycle arrest was also attenuated in the presence of p27 Kip1 knockdown. Taken together, hsa_circ_0001326 OE contributed to the decreased viability of SWAN71 cells by targeting miR-186-5p via upregulation of p27 Kip1. Our findings were helpful to uncover the pathophysiological process of PE, as well as inspire the development of novel targeted therapy against PE.

Hsa-miR-186-5p regulates TGFβ signaling pathway through expression suppression of SMAD6 and SMAD7 genes in colorectal cancer

TGFβ signaling is a known pathway to be involved in colorectal cancer (CRC) progression and miRNAs play crucial roles by regulating different components of this pathway. Hence, finding the link between miRNAs and the pathway could be beneficial for CRC therapy. Array data indicated that miR-186-5p is a differentially expressed miRNA in colorectal Tumor/Normal tissues and bioinformatics tools predicted SMAD6/7 (inhibitory SMADs) as bona fide targets of this miRNA. Here, we intended to investigate the regulatory effect of the miR-186-5p expression on TGFβ signaling in CRC. Firstly, the miR-186-5p overexpression in HCT116 cells resulted in a significant reduction of SMAD6/7 expression, measured through RT-qPCR. Then, the direct interactions of miR-186-5p with SMAD6/7 3'UTRs were supported through dual luciferase assay. Furthermore, miR-186-5p overexpression suppressed proliferation, cell viability, and migration while, it increased apoptosis in CRC cells, assessed by cell cycle, MTT, scratch and Annexin V/PI apoptosis assays. Consistently, miR-186-5p overexpression resulted in reduced CyclinD1 protein using western blot, and also resulted in increased P21 and decreased c-Myc expression. Overall, these results introduced miR-186-5p as a cell cycle suppressor through downregulation of SMAD6/7 expression. Thus, miR-186-5p might be served as a novel tumor suppressive biomarker and therapeutic target in CRC treatment.

MicroRNA‑186‑5p downregulation inhibits osteoarthritis development by targeting MAPK1

As a chronic degenerative joint disease, the characteristics of osteoarthritis (OA) are degeneration of articular cartilage, subchondral bone sclerosis and bone hyperplasia. It has been reported that microRNA (miR)-186-5p serves a key role in the development of various tumors, such as osteosarcoma, non-small-cell lung cancer cells, glioma and colorectal cancer. The present study aimed to investigate the effect of miR-186-5p in OA. Different concentrations of IL-1β were used to treat the human chondrocyte cell line CHON-001 to simulate inflammation, and CHON-001 cell injury was assessed by detecting cell viability, apoptosis, caspase-3 activity and the levels of TNF-α, IL-8 and IL-6. Subsequently, reverse transcription-quantitative PCR was performed to measure miR-186-5p expression. The results demonstrated that following IL-1β treatment, CHON-001 cell viability was suppressed, apoptosis was promoted, the caspase-3 activity was significantly enhanced and the release of TNF-α, IL-8 and IL-6 was increased. In addition, IL-1β treatment significantly upregulated miR-186-5p expression in CHON-001 cells. It was also identified that MAPK1 was a target gene of miR-186-5p, and was negatively regulated by miR-186-5p. miR-186 inhibitor and MAPK1-small interfering RNA (siRNA) were transfected into CHON-001 cells to investigate the effect of miR-186-5p on CHON-001 cell injury induced by IL-1β. The results demonstrated that miR-186 inhibitor suppressed the effects of IL-1β on CHON-001 cells, and these effects were reversed by MAPK1-siRNA. In conclusion, the present results indicated that miR-186-5p could attenuate IL-1β-induced chondrocyte inflammation damage by increasing MAPK1 expression, suggesting that miR-186-5p may be used as a potential therapeutic target for OA.

LncRNA NEAT1 promotes cell proliferation, migration, and invasion via the miR-186-5p/PTP4A1 axis in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a highly aggressive and malignant tumor. In this study, the effect and molecular mechanism of nuclear enriched abundant transcript 1 (NEAT1) in CCA were elucidated. The expressions of NEAT1, microRNA-186-5p (miR-186-5p), and PTP4A1 were measured by quantitative real-time PCR. The protein levels were measured by Western blotting. Kaplan-Meier analysis was performed to create survival curves. The interactions between NEAT1, miR-186-5p, and PTP4A1 were assessed through the dual luciferase reporter assay. Additionally, the cell proliferation, apoptosis, migration, and invasion were measured by colony formation, flow cytometry, the Transwell assay, and the wound healing assay, respectively. NEAT1 and PTP4A1 were significantly upregulated in CCA tissues and cells, but miR-186-5p was downregulated. NEAT1 expression was negatively correlated with the survival of CCA patients and has remarkable correlation with serum CA199 levels and lymph node metastasis. Besides, NEAT1 could act as a molecular sponge for miR-186-5p to upregulate PTP4A1 expression. More importantly, the knockdown of NEAT1 or overexpression of miR-186-5p inhibited the proliferation, migration and invasion of CCA cells, and the inhibition of miR-186-5p reversed the effects of the knockdown of NEAT1. In addition, NEAT1 could also activate the PI3K/AKT signaling pathway and regulate the epithelial-mesenchymal transition (EMT) through the miR-186-5p/PTP4A1 axis. In conclusion, NEAT1 was involved in cell proliferation, migration and invasion in CCA, and the NEAT1/miR-186-5p/PTP4A1/PI3K/AKT axis indicated novel regulatory mechanisms and therapeutics for the treatment of CCA.

MicroRNAs: Emerging oncogenic and tumor-suppressive regulators, biomarkers and therapeutic targets in lung cancer

Lung cancer is one of the most common solid tumors worldwide and the leading cause of cancer-related deaths, causing a devastating impact on human health. The clinical prognosis of lung cancer is usually restricted by delayed diagnosis and resistance to anticancer therapies. MicroRNAs, a range of small endogenous noncoding RNAs 22 nucleotides in length, have emerged as one of the most important players in cancer initiation and progression in recent decades. Current evidence reveals pivotal roles of microRNAs in regulating cell proliferation, migration, invasion and metastasis in lung cancer. An increasing number of preclinical and clinical studies have also explored the potential of microRNAs as promising biomarkers and new therapeutic targets for lung cancer. The current review summarizes the most recent progress on the functional mechanisms of microRNAs involved in lung cancer development and progression and further discusses the clinical application of miRNAs as putative therapeutic targets for molecular diagnosis and prognostic prediction in lung cancer.

microRNAs Mediated Regulation of the Ribosomal Proteins and its Consequences on the Global Translation of Proteins

Ribosomal proteins (RPs) are mostly derived from the energy-consuming enzyme families such as ATP-dependent RNA helicases, AAA-ATPases, GTPases and kinases, and are important structural components of the ribosome, which is a supramolecular ribonucleoprotein complex, composed of Ribosomal RNA (rRNA) and RPs, coordinates the translation and synthesis of proteins with the help of transfer RNA (tRNA) and other factors. Not all RPs are indispensable; in other words, the ribosome could be functional and could continue the translation of proteins instead of lacking in some of the RPs. However, the lack of many RPs could result in severe defects in the biogenesis of ribosomes, which could directly influence the overall translation processes and global expression of the proteins leading to the emergence of different diseases including cancer. While microRNAs (miRNAs) are small non-coding RNAs and one of the potent regulators of the post-transcriptional gene expression, miRNAs regulate gene expression by targeting the 3' untranslated region and/or coding region of the messenger RNAs (mRNAs), and by interacting with the 5' untranslated region, and eventually finetune the expression of approximately one-third of all mammalian genes. Herein, we highlighted the significance of miRNAs mediated regulation of RPs coding mRNAs in the global protein translation.

Regulatory role of microRNAs on PTEN signaling

Phosphatase and tensin homolog (PTEN) gene encodes a tumor suppressor protein which is altered in several malignancies. This protein is a negative regulator of the PI3K/AKT signaling. Several transcription factors regulate the expression of PTEN in positive or negative directions. Moreover, numerous microRNAs (miRNAs) have functional interactions with PTEN and inhibit its expression. Suppression of PTEN can attenuate the response of cancer cells to chemotherapeutic agents. Based on the critical role of this tumor suppressor gene, the identification of negative regulators of its expression has practical significance particularly in the prevention and management of cancer. Meanwhile, the interaction between miRNAs and PTEN has functional consequences in non-malignant disorders including myocardial infarction, osteoporosis, cerebral ischemic stroke, and recurrent abortion. In the present review, we describe the role of miRNAs in the regulation of expression and activity of PTEN.

Paired‑related homeobox 1 overexpression promotes multidrug resistance via PTEN/PI3K/AKT signaling in MCF‑7 breast cancer cells

Multidrug resistance (MDR) is a major cause of disease relapse and mortality in breast cancer. Paired‑related homeobox 1 (PRRX1) is associated with the epithelial‑mesenchymal transition (EMT), which is involved in tumor development, including cell invasion and MDR. However, the effect of PRRX1 on MDR had not clearly established. The present study investigated the influence of PRRX1 on MDR and the underlying molecular mechanisms in MCF‑7 breast cancer cells. MCF‑7 cells were divided into PRRX1+ group (cells transfected with a recombinant plasmid carrying the PRRX1 gene), negative control group (cells transfected with a blank vector) and blank group (untreated cells). It was found that the relative protein and mRNA expression levels of PRRX1, N‑cadherin, vimentin and P‑glycoprotein were significantly higher in PRRX1‑overexpressing MCF‑7 cells compared with those in control cells. The half‑maximal inhibitory concentration of three groups after treatment with docetaxel and cis‑platinum complexes were significantly higher in PRRX1‑overexpressing MCF‑7 cells compared with those in control cells. Furthermore, relative PTEN expression decreased significantly and levels of phosphorylated PI3K and AKT increased substantially in PRRX1‑overexpressing MCF‑7 cells. These results indicated that PRRX1 overexpression may induce MDR via PTEN/PI3K/AKT signaling in breast cancer. It is highly recommended that PRRX1 gene expression detection should be performed in patients with breast cancer to aid the selection of more appropriate treatments, which will lead to an improved prognosis in clinical practice.

Lnc00462717 regulates the permeability of the blood-brain tumor barrier through interaction with PTBP1 to inhibit the miR-186-5p/Occludin signaling pathway

Blood-brain tumor barrier (BTB) severely restricts the efficient delivery of chemotherapeutic drugs into brain tumor tissue, which is a critical obstacle for glioma treatment. Recently, long noncoding RNAs (lncRNAs) have shown as regulation factors of numerous biological processes. In this study, we identified that Lnc00462717 was upregulated in glioma endothelial cells (GECs), and that knockdown of Lnc00462717 significantly increased the BTB permeability. Both bioinformatics and RNA immunoprecipitation (RIP) results revealed that Lnc00462717 interacts with polypyrimidine tract binding protein (PTBP1). Moreover, overexpression of PTBP1 significantly reversed the increase in BTB permeability caused by siLnc00462717. Furthermore, the binding sites between miR-186 and PTBP1 as well as between miR-186 and 3'UTR of Occludin mRNA were confirmed by RIP and luciferase assays, respectively. And the interaction of Lnc00462717 and PTBP1 significantly facilitated the binding of PTBP1 to 3'UTR of Occludin mRNA and then blocked the miR-186-5p-induced downregulation of Occludin. In addition, we identified that knockdown of Lnc00462717 or overexpression of miR-186-5p increased the accumulation of doxorubicin (Dox) in brain glioma via the ultrafast liquid chromatography-mass spectrometry system (UFLC-MS/MS system) and decreased the intracranial glioma volume in BALB/c nude mice. Taken together, these results show a novel molecular pathway in BTB that may provide a potential innovative strategy for glioma therapy.

Icariin Attenuates Amyloid-β (Aβ)-Induced Neuronal Insulin Resistance Through PTEN Downregulation

Neuronal insulin resistance is implicated in neurodegenerative diseases. Icariin has been reported to improve insulin resistance in skeletal muscle cells and to restore impaired hypothalamic insulin signaling in the rats with chronic unpredictable mild stress. In addition, icariin can exert the neuroprotective effects in the mouse models of neurodegenerative diseases. However, the molecular mechanisms by which icariin affects neuronal insulin resistance are poorly understood. In the present study, amyloid-β (Aβ) was used to induce insulin resistance in human neuroblastoma SK-N-MC cells. Insulin sensitivity was evaluated by measuring insulin-stimulated Akt T308 phosphorylation and glucose uptake. We found that the phosphatase and tensin homologue deleted on chromosome 10 (PTEN) mediated Aβ-induced insulin resistance. Icariin treatment markedly reduced Aβ-enhanced PTEN protein levels, leading to an improvement in Aβ-induced insulin resistance. Accordingly, PTEN overexpression obviously abolished the protective effects of icariin on Aβ-induced insulin resistance. Furthermore, icariin activated proteasome activity. The proteasome inhibitor MG132 attenuated the effects of icariin on PTEN protein levels. Taken together, these results suggest that icariin protects SK-N-MC cells against Aβ-induced insulin resistance by activating the proteasome-dependent degradation of PTEN. These findings provide an experimental background for the identification of novel molecular targets of icariin, which may help in the development of alternative therapeutic approaches for neurodegenerative diseases.

MicroRNA-186-5p serves as a diagnostic biomarker in atherosclerosis and regulates vascular smooth muscle cell proliferation and migration

Objective

MicroRNA dysregulation occurs in many human diseases, including atherosclerosis. Here, we examined the serum expression and clinical significance of miR-186-5p in patients with atherosclerosis, and explored its influence on vascular smooth muscle cell (VSMC) proliferation and migration.

Methods

Blood samples were collected from 104 patients with asymptomatic atherosclerosis and 80 healthy controls. Quantitative real-time PCR was applied to measure the miR-186-5p level. An ROC curve was established to assess the discriminatory ability of the serum miR-186-5p level for identifying atherosclerosis from controls. CCK-8 and Transwell assays were used to evaluate the impact of miR-186-5p on cell behaviors.

Results

Serum expression of miR-186-5p was significantly higher in atherosclerosis patients than in the control group. The serum miR-186-5p level showed a positive correlation with CIMT and could be used to distinguish atherosclerosis patients from healthy controls, with an area under the curve (AUC) score of 0.891. In VSMCs, overexpression of miR-186-5p significantly promoted cell proliferation and migration, while the opposite results were observed when miR-186-5p was downregulated.

Conclusion

Overexpression of miR-186-5p has a certain diagnostic significance for atherosclerosis. Upregulation of miR-186-5p stimulates VSMC proliferation and migration. Therefore, it is a possible target for atherosclerosis interventions.

MiR-186 bidirectionally regulates cisplatin sensitivity of ovarian cancer cells via suppressing targets PIK3R3 and PTEN and upregulating APAF1 expression

Ovarian cancer is a highly lethal malignancy in the female reproductive system. Platinum drugs, represented by cisplatin, are the first-line chemotherapeutic agents for treatment of various malignancies including ovarian cancer, but drug resistance leads to chemotherapy failure. MicroRNAs emerged as promising molecules in reversal of cisplatin resistance. MiR-186 was reported to be downregulated in the cisplatin-resistant ovarian cell lines and miR-186 expression increased cisplatin sensitivity. However, we found the bidirectional regulatory effects of miR-186 on cisplatin sensitivity for the first time that overexpression of miR-186 at low concentration increased the cisplatin sensitivity of ovarian cancer cells A2780/DDP, while high concentration of miR-186 decreased the cisplatin sensitivity. The survival assay in other types of cancer cell lines verified the bidirectional regulatory function of miR-186 on cisplatin sensitivity in dose and cell type dependent manners. MiR-186 suppressed the protein levels of PTEN and PIK3R3 dose-dependently, which are opposite regulatory molecules of the oncogenic AKT pathway. MiR-186 also enhanced the protein levels of apoptotic gene APAF1 dose-dependently. We proposed the final effects of PTEN and APAF1 outweighed PIK3R3 when miR-186 at low concentration so as to increase the cisplatin sensitivity of ovarian cancer cells, while the final effects of PIK3R3 outweighed PTEN and APAF1 when miR-186 at high concentration so as to decrease the cisplatin sensitivity. We concluded the outcome of regulation of these opposite functional molecules contributed to the bidirectional regulatory effects of miR-186 in ovarian cancer cisplatin sensitivity. It deserves more attentions when developing therapeutic strategies based on the bidirectional functional miRNAs.

The Dual Role of miR-186 in Cancers: Oncomir Battling With Tumor Suppressor miRNA

MicroRNAs (miRNAs) are a class of small non-coding RNAs which regulate gene expression at post-transcriptional level. Alterations of miR-186 expression were demonstrated in numerous cancers, shown to play a vital role in oncogenesis, invasion, metastasis, apoptosis, and drug resistance. MiR-186 was documented as a tumor suppressor miRNA in the majority of studies, while conflicting reports verified miR-186 as an oncomir. The contradictory role in cancers may impede the application of miR-186, as well as other dual-functional miRNAs, as a diagnostic and therapeutic target. This review emphasizes the alterations and functions of miR-186 in cancers and discusses the mechanisms behind the contradictory findings. Among these, target abundance and dose-dependent effects of miR-186 are highlighted. The paper aims to review the challenges involved in developing diagnostic and therapeutic strategies for cancer treatment based on dual-functional miRNAs.

MicroRNA-186-5p Inhibits Proliferation And Metastasis Of Esophageal Cancer By Mediating HOXA9

Objective

MicroRNA (miRNA) is an endogenous, non-coding small RNA that plays a key role in regulating organism biology and pathology. The aim of this study was to investigate the expression characteristics of microRNA-186-5p in esophageal cancer (ECa) and its correlation with clinical progression and prognosis, and to further explore its underlying mechanisms.

Methods

Real-time quantitative PCR (qRT-PCR) was used to detect microRNA-186-5p level in 45 pairs of ECa tissue samples and adjacent ones, and to analyze the expression of microRNA-186-5p and clinical progression of ECa and prognosis. The relationship between microRNA-186-5p level in ECa cell lines was further verified by qRT-PCR. Finally, the potential mechanism was explored using luciferase reporter gene assay and cell recovery experiment.

Results

QRT-PCR results revealed that the expression of microRNA-186-5p in ECa tissues was remarkably lower than that in adjacent tissues, and the difference was statistically significant. Compared with patients with high expression of microRNA-186-5p, patients with low expression of microRNA-186-5p had higher incidence of pathological stage and lower overall survival rate. Besides, compared with the miR-NC group, the microRNA-186-5p mimics group had a significant decrease in proliferation and metastasis ability of ECa cells. Subsequent qRT-PCR validation in ECa cell lines and tissues indicated a significant increase in HOXA9 expression and a negative correlation with microRNA-186-5p.

Conclusion

The expression of microRNA-186-5p was remarkably decreased in ECa, which was remarkably correlated with pathological stage, distant metastasis and poor prognosis of ECa. The results suggested that microRNA-186-5p may inhibit cell proliferation of ECa by regulating HOXA9.