miR-186-5p improves alveolar epithelial barrier function by targeting the wnt5a/β-catenin signaling pathway in sepsis-acute lung injury

BACKGROUND

Alveolar epithelial barrier dysfunction is one of the pathological features of sepsis-acute lung injury(ALI). However, the molecular mechanisms that regulate the function of alveolar epithelial barrier remain unclear. This study aimed to determine the regulatory role of miR-186-5p in alveolar epithelial barrier function in sepsis-ALI and its underlying molecular mechanism.

METHODS

We established sepsis-ALI models in vivo and in vitro, detected the miR-186-5p and wnt5a/β-catenin expressions, and observed the functional changes of the alveolar epithelial barrier by miR-186-5p overexpression. We used rescue experiments to clarify whether miR-186-5p works through wnt5a/β-catenin.

RESULTS

miR-186-5p expression was decreased, wnt5a expression was increased, and the wnt5a/β-catenin signaling pathway was activated in mouse lung tissues and A549 cells after inflammatory stimulation. miR-186-5p overexpression resulted in wnt5a/β-catenin signaling pathway inhibition, decreased apoptosis in A549 cells, improved alveolar epithelial barrier function, reduced lung tissue injury in ALI mice, decreased IL-6 and TNF-α levels, and increased claudin4 and ZO-1 expression. Using miRNA-related database prediction and dual-luciferase reporter gene analysis, the targeting relationship between miR-186-5p and wnt5a was determined. The protective effect produced by miR-186-5p overexpression on the alveolar barrier was reversed after the application of the wnt5a/β-catenin activator Licl.

CONCLUSION

Our experimental data suggest miR-186-5p targets the wnt5a/β-catenin pathway, thereby regulating alveolar epithelial barrier function. Furthermore, both miR-186-5p and wnt5a/β-catenin are potential therapeutic targets that could impact sepsis-ALI.

Sufentanil Suppresses Cell Carcinogenesis Via Targeting miR-186-5p/HMGB1 Axis and Wnt/β-Catenin Pathway in Non-Small-Cell Lung Cancer

Sufentanil is a common opioid anesthetic agent, which exerts anti-cancer properties in several cancer types. However, its action mechanisms in non-small cell lung cancer (NSCLC) are unclear. Therefore, the present study investigated the pharmacological effect of sufentanil on miRNAs in NSCLC treatment. In this study, after treatment with sufentanil, the proliferation, migration, invasion and apoptosis of A549 and H1299 NSCLC cell lines were measured by cell counting kit-8 (CCK-8) assay, colony formation assay, transwell assays and flow cytometry. Quantitative real time polymerase chain reaction (qRT-PCR) was utilized to detect the expression of miR-186-5p and high mobility group box-1 (HMGB1), and their interaction was analyzed using luciferase reporter assay. The proteins of HMGB1, and apoptosis- and Wnt/β-catenin pathway-related factors were detected by western blot. It was demonstrated that sufentanil significantly upregulated miR‑186‑5p to restrict NSCLC cell proliferation, migration, invasion, and boost apoptosis in vitro. Mechanically, miR-186-5p interacted with HMGB1 and negatively regulated HMGB1 in NSCLC cells. Furthermore, rescue assay showed that sufentanil exerted antitumor activities by upregulating miR-186-5p, which targeted HMGB1 and restrained Wnt/β-catenin signal pathway in NSCLC cells. In conclusion, these results suggested that sufentanil disrupts the oncogenicity of NSCLC cells by regulating miR-186-5p/HMGB1/β-catenin axis, providing a promising implication for the anti-oncogenic effect of sufentanil.

M1 Macrophage-Derived Exosome LncRNA PVT1 Promotes Inflammation and Pyroptosis of Vascular Smooth Muscle Cells in Abdominal Aortic Aneurysm by Inhibiting miR-186-5p and Regulating HMGB1

Abdominal aortic aneurysm (AAA) is a chronic vascular degenerative disease. Vascular smooth muscle cells (VSMCs) are essential for maintaining the integrity of healthy blood vessels. Macrophages play an important role in the inflammatory process of AAA. However, the effect of macrophage-derived exosome LncRNA PVT1 on VSMCs is unclear. Exosomes from M1 macrophages (M1φ-exos) were isolated and identified. The expression of LncRNA PVT1 in M1φ-exos was determined. AAA cell model was constructed by treating VSMCs with Ang-II. AAA cell model was treated with M1φ exosomes transfected with si-LncRNA PVT1 (M1φsi-LncRNA PVT1-exo). VSMCs were transfected with miR-186-5p mimic and oe-HMGB1. Cell viability was detected by CCK-8. The accumulation of LDH was detected by ELISA. Western blot was used to detect the expression of HMGB1, inflammatory factors (IL-6, TNF-α and IL-1β) and pyroptosis-related proteins (GSDMD, N-GSDMD, ASC, NLRP3, Caspase-1 and Cleaved-Capase-1). Cell pyroptosis rate was detected by flow cytometry. At the same time, the targeting relationship between miR-186-5p and LncRNA PVT1 and HMGB1 was verified by double fluorescein experiment. Exosomes from M1φ were successfully extracted. The expression of LncRNA PVT1 in M1φ-exos was significantly increased. M1φ-exo promotes inflammation and pyroptosis of VSMCs. M1φsi-LncRNA PVT1-exos inhibited the inflammation and pyroptosis of VSMCs. LncRNA PVT1 can sponge miR-186-5p mimic to regulate HMGB1 expression. MiR-186-5p mimic further inhibited inflammation and pyroptosis induced by M1φsi-LncRNA PVT1-exos. However, oe-HMGB1 could inhibit the reversal effect of miR-186-5p mimic. LncRNA PVT1 in exosomes secreted by M1φ can regulate HMGB1 by acting as ceRNA on sponge miR-186-5p, thereby promoting cell inflammatory and pyroptosis and accelerating AAA progression.

miR-186-5p targets TGFβR2 to inhibit RAW264.7 cell migration and proliferation during mouse skin wound healing

BACKGROUND

Active peptides play a vital role in the development of new drugs and the identification and discovery of drug targets. As the first reported native peptide homodimer with pro-regenerative potency, OA-GP11d could potentially be used as a novel molecular probe to help elucidate the molecular mechanism of skin wound repair and provide new drug targets.

METHODS

Bioinformatics analysis and luciferase assay were adopted to determine microRNAs (miRNAs) and its target. The prohealing potency of the miRNA was determined by MTS and a Transwell experiment against mouse macrophages. Enzyme-linked immunosorbent assay, realtime polymerase chain reaction, and western blotting were performed to explore the molecular mechanisms.

RESULTS

In this study, OA-GP11d was shown to induce Mus musculus microRNA-186-5p (mmu-miR-186-5p) down-regulation. Results showed that miR-186-5p had a negative effect on macrophage migration and proliferation as well as a targeted and negative effect on TGF-β type II receptor (TGFβR2) expression and an inhibitory effect on activation of the downstream SMAD family member 2 (Smad2) and protein-p38 kinase signaling pathways. Importantly, delivery of a miR-186-5p mimic delayed skin wound healing in mice.

CONCLUSION

miR-186-5p regulated macrophage migration and proliferation to delay wound healing through the TGFβR2/Smad2/p38 molecular axes, thus providing a promising new pro-repair drug target.

[Mechanism of miR-186-5p Regulating PRKAA2 to Promote Ferroptosis in Lung Adenocarcinoma Cells]

BACKGROUND

Lung adenocarcinoma (LUAD) is the most common type of non-small cell lung cancer, and any change of miRNAs expression will affect the degree of target regulation, thus affecting intracellular homeostasis. This study verified that miR-186-5p could inhibit the proliferation, migration and invasion of LUAD cells by regulating PRKAA2.

METHODS

Previous investigations found that the expression of miR-186-5p was markedly suppressed in LUAD. Bioinformatics method is used to predict the target protein related to ferroptosis downstream and inquire about its expression level in LUAD and its influence on the survival of patients. Double luciferase verified the binding site of PRKAA2 and miR-186-5p. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to detect the expression of PRKAA2. The effects of miR-186-5p of LUAD cells as well as the mechanism by which miR-186-5p inhibits Fer-1's sensitivity to ferroptosis were confirmed by EdU, Transwell, and scratch assays. The effect of miR-186-5p on the amount of reactive oxygen species (ROS) in LUAD cells was discovered using ROS experiment. Malondialdehyde (MDA) and glutathione (GSH) experiments were used to detect the effects of miR-186-5p and PRKAA2 on ferroptosis index of LUAD cells. The concentration of lipid ROS (L-ROS) in LUAD cells were measured using the L-ROS tests to determine the effects of miR-186-5p and PRKAA2.

RESULTS

The expression of PRKAA2 is up-regulated, and a high level of PRKAA2 expression was associated with a poor prognosis for patients with LUAD. Overexpression of miR-186-5p decreased the gene and protein expression of PRKAA2. By promoting ferroptosis, miR-186-5p overexpression prevented lung cancer cells from proliferating, invading, and migrating. ROS could be produced in higher amounts in LUAD cells due to miR-186-5p. Overexpression of miR-186-5p and knockdown PRKAA2 up-regulated MDA content and reduced GSH content in LUAD cells, respectively. miR-186-5p could increase the content of L-ROS and promote the ferroptosis sensitivity of LUAD cells by targeting PRKAA2.

CONCLUSIONS

miR-186-5p promotes ferroptosis of LUAD cells through targeted regulation of PRKAA2, thus inhibiting the proliferation, invasion and migration of LUAD.
.

Exosomal long noncoding RNA MLETA1 promotes tumor progression and metastasis by regulating the miR-186-5p/EGFR and miR-497-5p/IGF1R axes in non-small cell lung cancer

BACKGROUND

Lung cancer is the most common and deadliest cancer worldwide, and approximately 90% of all lung cancer deaths are caused by tumor metastasis. Tumor-derived exosomes could potentially promote tumor metastasis through the delivery of metastasis-related molecules. However, the function and underlying mechanism of exosomal long noncoding RNA (lncRNA) in lung cancer metastasis remain largely unclear.

METHODS

Cell exosomes were purified from conditioned media by differential ultracentrifugation and observed using transmission electron microscopy, and the size distributions were determined by nanoparticle tracking analysis. Exosomal lncRNA sequencing (lncRNA-seq) was used to identify long noncoding RNAs. Cell migration and invasion were determined by wound-healing assays, two-chamber transwell invasion assays and cell mobility tracking. Mice orthotopically and subcutaneously xenografted with human cancer cells were used to evaluate tumor metastasis in vivo. Western blot, qRT‒PCR, RNA-seq, and dual-luciferase reporter assays were performed to investigate the potential mechanism. The level of exosomal lncRNA in plasma was examined by qRT‒PCR. MS2-tagged RNA affinity purification (MS2-TRAP) assays were performed to verify lncRNA-bound miRNAs.

RESULTS

Exosomes derived from highly metastatic lung cancer cells promoted the migration and invasion of lung cancer cells with low metastatic potential. Using lncRNA-seq, we found that a novel lncRNA, lnc-MLETA1, was upregulated in highly metastatic cells and their secreted exosomes. Overexpression of lnc-MLETA1 augmented cell migration and invasion of lung cancer. Conversely, knockdown of lnc-MLETA1 attenuated the motility and metastasis of lung cancer cells. Interestingly, exosome-transmitted lnc-MLETA1 promoted cell motility and metastasis of lung cancer. Reciprocally, targeting lnc-MLETA1 with an LNA suppressed exosome-induced lung cancer cell motility. Mechanistically, lnc-MLETA1 regulated the expression of EGFR and IGF1R by sponging miR-186-5p and miR-497-5p to facilitate cell motility. The clinical datasets revealed that lnc-MLETA1 is upregulated in tumor tissues and predicts survival in lung cancer patients. Importantly, the levels of exosomal lnc-MLETA1 in plasma were positively correlated with metastasis in lung cancer patients.

CONCLUSIONS

This study identifies lnc-MLETA1 as a critical exosomal lncRNA that mediates crosstalk in lung cancer cells to promote cancer metastasis and may serve as a prognostic biomarker and potential therapeutic target for lung cancer diagnosis and treatment.

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.

N6 -methyladenosine-modified circFUT8 competitively interacts with YTHDF2 and miR-186-5p to stabilize FUT8 mRNA to promote malignant progression in lung adenocarcinoma

BACKGROUND

Lung cancer is the leading cause of cancer related to mortality worldwide, and the main pathological type is lung adenocarcinoma (LUAD). Circular RNAs (circRNAs) have been reported to be modified by N6 -methyladenosine (m6A), which is involved in the progression of diverse tumors. However, the crosstalk between circRNAs and m6A modification has not been well elucidated in LUAD.

METHODS

MeRIP-seq and YTHDF2-RIP-seq datasets were explored to identify candidate circRNAs modified by YTHDF2. Dual-luciferase reporter assay, RIP, and rescue assays were performed to explore the relationship between circFUT8 and its parent mRNA of FUT8. In vitro and in vivo experiments were utilized to uncover the function of circFUT8.

RESULTS

In this study, we identified a novel m6A-modified circFUT8, derived from exon 3 of FUT8, which was elevated in tumor tissues compared with adjacent noncancerous tissues. The m6A reader YTHDF2 recognized and destabilized circFUT8 in an m6A-dependent manner. YTHDF2 also combined with the line form of FUT8 (mFUT8), and circFUT8 competitively interacted with YTHDF2, blunting its binding to mFUT8, to stabilize the mRNA level of FUT8. Additionally, circFUT8 sponged miR-186-5p to elevate the expression of mFUT8. Finally, we revealed that circFUT8 promoted the malignant progression of LUAD dependent on the oncogenic function of FUT8.

CONCLUSIONS

These findings identified a novel m6A-modified circFUT8 recognized and destabilized by YTHDF2, which competitively interacted with YTHDF2 and miR-186-5p to stabilize FUT8 mRNA to promote malignant progression in LUAD.

miR-186-ANXA9 signaling inhibits tumorigenesis in breast cancer

Breast cancer (BC) ranks as the highest incidence among cancer types in women all over the world. MicroRNAs (miRNAs) are a class of short endogenous non-coding RNA in cells mostly functioning to silence the target mRNAs. In the current study, a miRNA screening analysis identified miR-186-5p to be downregulated in human breast cancer tumors. Functional studies in vitro demonstrated that overexpression of miR-186-5p inhibited cellular proliferation and induced cell apoptosis in multiple breast cancer cell lines including MDA-MB-231, MCF-7, and BT549 cells. Transplantation of the miR-186-5p-overexpressing MDA-MB-231 cells into nude mice significantly inhibited mammary tumor growth in vivo. Sequence blast analysis predicted annexin A9 (ANXA9) as a target gene of miR-186-5p, which was validated by luciferase reporter assay, QRT-PCR analysis, and western blot. Additional gene expression analysis of clinical tumor samples indicated a negative correlation between miR-186-5p and ANXA9 in human breast cancer. Knockdown of ANXA9 mimicked the phenotype of miR-186-5p overexpression. Reintroduction of ANXA9 back rescued the miR-186-5p-induced cell apoptosis. In addition, miR-186-5p decreased the expression of Bcl-2 and increased the expression of p53, suggesting a mechanism regulating miR-186-5p-induced cellular apoptosis. In summary, our study is the first to demonstrate miR-186-5p-ANXA9 signaling in suppressing human breast cancer. It provided a potential therapeutic target in breast cancer.

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.

MicroRNA-186-5p inhibits H9c2 cells apoptosis induced by oxygen-glucose deprivation by targeting ERK1/2

Background

Serum miR-186-5p levels are increased in acute myocardial infarction (AMI) patients and might contribute to assessing the prognosis of AMI patients. In this study, we further investigated the underlying molecular mechanism of miR-186-5p that participated in the pathological processes of myocardial ischemia.

Methods

The AMI models of rats and oxygen-glucose deprivation (OGD) models of H9c2 cells were established. Bioinformatics databases, luciferase reporting, and western blotting assays were performed to identify the regulatory target of miR-186-5p. Transfection and functional experiments were conducted to further define the possible molecular mechanism of miR-186-5p during the process of glucose deficiency and hypoxia.

Results

The level of miR-186-5p was found to significantly decrease in H9c2 cells after OGD treatment, while it increased in the culture medium from OGD-treated H9c2 cells. Using bioinformatics databases, luciferase reporting, and western blotting assays, we identified that ERK1/2 might serve as the negative regulatory target of miR-186-5p. Combined with further transfection experiments, we indicated that miR-186-5p might inhibit the expression and activation of ERK1/2. This finding was also reflected in the reduction of their downstream cleaved caspase-3. Through functional experiments, we revealed that miR-186-5p might inhibit apoptosis and promote proliferation in OGD-treated H9c2 cells.

Conclusions

We demonstrated that miR-186-5p might suppress OGD-induced apoptosis in H9c2 cells by targeting the ERK1/2 pathway.

Silencing long non-coding RNA SNHG3 repairs the dysfunction of pulmonary microvascular endothelial barrier by regulating miR-186-5p/Wnt axis

Barrier permeability changes of human pulmonary microvascular endothelial cells (HPMVECs) are important in sepsis-related acute lung injury (ALI) pathogenesis. Long non-coding small nucleolar RNA host gene 3 (SNHG3) mediates the cell-biological phenotype of lung cancer cells and affects the progression of lung cancer, but its role in regulating functions of lung non-malignant cells is still rarely reported. Therefore, we evaluated the regulatory effect of SNHG3 on the function of PMVECs in sepsis-related ALI. Small interference RNA (siRNA)-mediated deletion of SNHG3 promoted the proliferation of PMVECs, reduced apoptosis and barrier permeability, and increased the expression of tight junction proteins claudin-5 and ZO-1. Knockdown of SNHG3 increased the miR-186-5p expression, while overexpression of SNHG3 upregulated the level of wnt5a. Through a dual luciferase reporter assay, we confirmed the binding between SNHG3 and miR-186-5p, miR-186-5p and wnt5a. We further found that knockout of miR-186-5p could inhibit cell proliferation, increase apoptosis and barrier permeability, and down-regulate claudin-5 and ZO-1. Importantly, silencing miR-186-5p and activating Wnt signal pathway could eliminate the barrier repair effect caused by down-regulation of SNHG3. To sum up, our results suggested that knockdown of long non-coding RNA SNHG3 repaired the dysfunction of pulmonary microvascular endothelial barrier through the miR-186-5p/Wnt axis.

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.

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.

Hsa_circ_0044907 promotes acute myeloid leukemia progression through upregulating oncogene KIT via sequestering miR-186-5p

BACKGROUND

It has been reported that circular RNA hsa_circ_0044907 (circ_0044907) expression is overtly elevated in acute myeloid leukemia (AML) patient-derived BMMCs. However, the effect of circ_0044907 on AML progression remains un-clarified.

METHODS

Expression of circ_0044907 in BM and AML cells were detected with real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR). Cell viability, proliferation, apoptosis, and cycle progression were determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), 5-ethynyl-2'-deoxyuridine (EDU), and flow cytometry assays. The regulatory mechanism of circ_0044907 was predicted by bioinformatics analysis and validated by dual-luciferase reporter, RNA pull-down, and RNA immunoprecipitation (RIP) assays. In vivo experiments were carried out to verify the function of circ_0044907.

RESULTS

Circ_0044907 was overexpressed in AML patient-derived BM and AML cells. Furthermore, circ_0044907 could distinguish AML patients from healthy controls, and high circ_0044907 expression in BM had a poor prognosis for AML patients, implying that circ_0044907 served as a diagnostic and prognostic indicator for AML. Functionally, circ_0044907 silencing reduced cell viability, restrained cell proliferation, arrested cell cycle progression, and induced cell apoptosis in AML cells in vitro. Furthermore, circ_0044907 knockdown decreased AML cell growth in xenograft mouse models. Mechanically, circ_0044907 sponged miR-186-5p to block the inhibiting effect of miR-186-5p on KIT. Silenced miR-186-5p expression weakened circ_0044907 knockdown mediated suppression on AML cell viability, proliferation, and cycle progression. Also, forced KIT expression weakened miR-186-5p upregulation mediated inhibition on AML cell viability, proliferation, and cycle progression.

CONCLUSION

Circ_0044907 absorbed miR-186-5p to block the inhibiting impact of miR-186-5p on KIT, thus promoting AML progression.

Knockdown circZNF131 Inhibits Cell Progression and Glycolysis in Gastric Cancer Through miR-186-5p/PFKFB2 Axis

Gastric cancer (GC) is a prevalent and heterogeneous malignancy in the digestive system. Increasing studies have suggested that circular RNAs are implicated in GC pathogenesis. This study aimed to explore the biological role and underlying mechanism of circRNA zinc finger protein 131 (circZNF131) in GC. The expression pattern of circZNF131, microRNA-186-5p (miR-186-5p), and 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 2 (PFKFB2) mRNA in GC tissues and cells was detected by quantitative real-time polymerase chain reaction. The stability of circZNF131 was verified using ribonuclease R assay. Functional experiments were performed by colony formation assay for cloning ability analysis, transwell assay and wounding healing assay for cell metastasis, and flow cytometry for cell apoptosis. Glycolysis metabolism was investigated by determining the levels of glucose uptake and lactate production. The protein detection of apoptosis- or glycolysis-associated markers, PFKFB2, and Ki-67 was implemented by western blot or immunohistochemistry. Dual-luciferase reporter assay was conducted to identify the interaction between miR-186-5p and circZNF131 or PFKFB2. The role of circZNF131 on tumor growth in nude mice was investigated via xenograft tumor assay. Expression analysis indicated that circZNF131 was upregulated in GC tissues and cells in a stable structure. Functional analyses showed that circZNF131 knockdown suppressed GC cell colony formation ability, migration, invasion and glycolysis metabolism, and induced cell apoptosis. Mechanically, miR-186-5p was a target of circZNF131, and miR-186-5p could bind to PFKFB2. Rescue experiments presented that miR-186-5p inhibition reversed the effects of circZNF131 knockdown on GC cell growth and glycolysis, and PFKFB2 overexpression abolished the impacts of miR-186-5p restoration on GC cell progression. Moreover, circZNF131 could positively modulate PFKFB2 expression via sponging miR-186-5p. In vivo, circZNF131 knockdown hindered GC tumor growth by regulating the miR-186-5p/PFKFB2 axis. circZNF131 could exert an oncogenic role in GC malignant development through the miR-186-5p/PFKFB2 axis, which might provide novel targets for GC treatment.

SNHG1-miR-186-5p-YY1 feedback loop alleviates hepatic ischemia/reperfusion injury

As a common cause of liver injury, hepatic ischemia/reperfusion injury (HIRI) happens in various clinical conditions including trauma, hepatectomy and liver transplantation. Since transcription factor Yin Yang 1 (YY1) was reported to be downregulated after ischemia/reperfusion (I/R) injury, we focused on YY1 to explore its function in HIRI by functional assays like Cell Counting Kit-8 (CCK-8) assays and flow cytometry assays. The RT-qPCR assay revealed that YY1 was downregulated in hepatocytes after I/R injury. The function assays disclosed that YY1 facilitated cell viability and proliferation, but hindered cell apoptosis in hepatocytes after I/R injury. Through mechanism assays including luciferase reporter assay, RIP and RNA pulldown assay, miR-186-5p was found to bind with YY1 and promote hepatocyte apoptosis by targeting YY1. Subsequently, we verified that small nucleolar RNA host gene 1 (SNHG1) could sponge miR-186-5p to upregulate YY1. Importantly, we figured out that YY1 had a positive regulation on SNHG1. Along the way, YY1 was identified as the upstream transcription factor for SNHG1. In conclusion, our study unveiled a novel competing endogenous RNA (ceRNA) pattern of SNHG1/miR-186-5p/YY1 positive feedback loop in hepatic I/R injury, which might provide new insight into prevention of HIRI during liver transplantation or hepatic surgery.

miR-186-5p inhibits the progression of oral squamous cell carcinoma by targeting ITGA6 to impair the activity of the PI3K/AKT pathway

BACKGROUND

microRNAs (miRNAs) are pivotal regulators of multiple biological processes. miR-186-5p functions as a tumor suppressor in a variety of cancers and promotes the malignant proliferation of oral squamous cell carcinoma (OSCC). This study aimed to clarify the role and regulatory mechanism of miR-186-5p in OSCC.

METHODS

The levels of miR-186-5p and integrin subunit alpha 6 (ITGA6) were investigated in clinical specimens and OSCC cell lines by reverse transcription-quantitative polymerase chain reaction. The effects of miR-186-5p and ITGA6 on the cell migration, proliferation, and phosphatidylinositol 3-kinase (PI3K)/serine-threonine kinase (AKT) pathway activity were evaluated by transwell assay, cell counting kit 8 assay, and western blotting, respectively. A xenograft model was used to analyze the effect of miR-186-5p on tumor growth. Bioinformatic analyses were conducted to identify the putative targets of miR-186-5p in OSCC.

RESULTS

Decreased miR-186-5p expression levels were observed in OSCC tumor tissues and cell lines. The overexpression of miR-186-5p suppressed the proliferation and migration of OSCC cells, and weakened the phosphorylation of PI3K and AKT. Moreover, the overexpression of miR-186-5p in xenograft tumor models impedes tumor growth. miR-186-5p is bound to ITGA6 and negatively related to ITGA6 expression in tumor tissues. The forced expression of ITGA6 promoted OSCC cell proliferation and migration and enhanced the phosphorylation levels of PI3K and AKT, while additional miR-186-5p enrichment partly abolished these effects.

CONCLUSION

miR-186-5p binds to ITGA6 to impair the activity of the PI3K/AKT signaling pathway, thereby blocking the development of OSCC. This study provides insight to understand the pathogenesis of OSCC.

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.

miR-185-5p alleviates CCI-induced neuropathic pain by repressing NLRP3 inflammasome through dual targeting MyD88 and CXCR4

MicroRNAs (miRNAs) are important modulators in the evolvement and progression of neuropathic pain (NP). According to reports, miR-185-5p contributes to various diseases and inflammatory responses. However, it is not clear whether miR-185-5p mediates neuroinflammation and NP following chronic constrictive injury (CCI). The CCI model was constructed in rats to induce NP. Paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were employed to evaluate pain threshold in CCI rats. The expression of miR-185-5p, GFAP, Iba1, Caspase-3-positive cells, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-labeled apoptotic neurons, inflammatory mediators, including interleukin (IL)-6, IL-1β and tumor necrosis factor-α (TNF-α) in lumbar portion (L4-L6) of CCI rats were determined. Furthermore, the targets of miR-185-5p were predicted by the Starbase, and the binding association between miR-185-5p and MyD88, miR-185-5p and CXCR4 was verified by the dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. As shown by the data, miR-185-5p was distinctly reduced in L4-L6 spinal cord tissues of rats after CCI. Up-regulating miR-185-5p alleviated mechanical and thermal hyperalgesia, inactivated microglia and astrocytes accumulation, and abated the contents of IL-1β, IL-6 and TNF-α in L4-L6 spinal cord tissues of CCI rats. Bioinformatics analysis suggested that MyD88 and CXCR4 were potential target genes of miR-185-5p. Increasing miR-185-5p expression notably impeded the expression of MyD88, CXCR4 and NLRP3 inflammasome in BV2 microglia, while attenuating miR-185-5p expression exerted the opposite effects. Notably, down-regulating MyD88 and CXCR4 significantly enhanced the miR-185-5p-mediated anti-inflammatory effects, and reversed miR-185-5p inhibitor-mediated proinflammatory effects. Additionally, up-regulating miR-185-5p repressed BV2-induced neuronal apoptosis and increased neuronal viability. In conclusion, this study suggested that miR-185-5p chokes CCI-induced NP and neuroinflammation by targeting MyD88 and CXCR4, indicating that miR-186-5p is an underlying therapeutic target for NP.

LncRNA SOX2-OTinhibitionprotects against myocardialischemia/reperfusion-inducedinjury via themicroRNA-186-5p (miR-186-5p)/Yin Yang 1 (YY1)pathway

Long noncoding RNAs (lncRNAs) exert essential effects in regulating myocardial ischemia/reperfusion (MI/R)-induced injury. This work intended to explore the functions of lncRNA SOX2-OT and its regulatory mechanism within MI/R-induced injury. In this study, gene expression was determined by RT-qPCR. Western blotting was applied for the detection of protein levels. Pro-inflammatory cytokine concentrations, cardiomyocyte viability, and apoptosis were detected via ELISA, CCK-8 and flow cytometry. In the in vitro model, SOX2-OT and YY1 were both upregulated, while miR-186-5p was downregulated. SOX2-OT knockdown attenuated oxygen-glucose deprivation/reoxygenation (OGD/R)-induced cardiomyocyte dysregulation through relieving inflammation, promoting proliferation, and reducing apoptosis in OGD/R-treated H2C9 cells. SOX2-OT positively regulated YY1 expression via miR-186-5p. Moreover, miR-186-5p inhibition or YY1 upregulation abolished the effects of SOX2-OT blocking on the inflammatory responses, proliferation, and apoptosis of OGD/R-challenged H2C9 cells. In conclusion, our results, for the first time, demonstrated that SOX2-OT inhibition attenuated MI/R injury in vitro via regulating the miR-186-5p/YY1 axis, offering potential therapeutic targets for MI/R injury treatment.

Oleanolic Acid Inhibits Neuronal Pyroptosis in Ischaemic Stroke by Inhibiting miR-186-5p Expression

Ischaemic stroke is a common condition leading to human disability and death. Previous studies have shown that oleanolic acid (OA) ameliorates oxidative injury and cerebral ischaemic damage, and miR-186-5p is verified to be elevated in serum from ischaemic stroke patients. Herein, we investigated whether OA regulates miR-186-5p expression to control neuroglobin (Ngb) levels, thereby inhibiting neuronal pyroptosis in ischaemic stroke. Three concentrations of OA (0.5, 2, or 8 μM) were added to primary hippocampal neurons subjected to oxygen–glucose deprivation/reperfusion (OGD/R), a cell model of ischaemic stroke. We found that OA treatment markedly inhibited pyroptosis. qRT–PCR and western blot revealed that OA suppressed the expression of pyroptosis-associated genes. Furthermore, OA inhibited LDH and proinflammatory cytokine release. In addition, miR-186-5p was downregulated while Ngb was upregulated in OA-treated OGD/R neurons. MiR-186-5p knockdown repressed OGD/R-induced pyroptosis and suppressed LDH and inflammatory cytokine release. In addition, a dual luciferase reporter assay confirmed that miR-186-5p directly targeted Ngb. OA reduced miR-186-5p to regulate Ngb levels, thereby inhibiting pyroptosis in both OGD/R-treated neurons and MCAO mice. In conclusion, OA alleviates pyroptosis in vivo and in vitro by downregulating miR-186-5p and upregulating Ngb expression, which provides a novel theoretical basis illustrating that OA can be considered a drug for ischaemic stroke.

MiR-186-5p suppresses cell migration, invasion, and epithelial mesenchymal transition in bladder cancer by targeting RAB27A/B

Bladder cancer (BCa) is a common malignancy in the urinary system. Ras-related protein Rab-27A (RAB27A) and Ras-related protein Rab-27B (RAB27B) have been verified to be closely related to the development of many tumors. Since the role of both RAB27A and RAB27B in BCa have not been reported, we intended to explore the function and mechanism of RAB27A and RAB27B in BCa development. Reverse transcription quantitative polymerase chain reaction revealed that RAB27A/B showed high expression in BCa tissues and cells. Cell counting kit-8, wound healing and Transwell assays as well as western blot analyses revealed that silencing RAB27A/B suppressed BCa cell proliferation, migration and invasion as well as the epithelial-mesenchymal transition (EMT) process. Based on bioinformatics analysis and our experiments, microRNA-186-5p (miR-186-5p) was found to be the upstream miRNA of RAB27A/B in BCa. MiR-186-5p expression was significantly downregulated in BCa cells and tissues. MiR-186-5p directly targeted the 3'-untranslated region (3'-UTR) of RAB27A/B and downregulated both mRNA and protein levels of RAB27A/B in BCa cells. MiR-186-5p overexpression suppressed BCa cell proliferation, migration and invasion as well as the EMT process in vitro and inhibited tumor growth in vivo. Overexpressing RAB27A/B rescued the inhibitory effect of miR-186-5p on malignant phenotypes of BCa cells. Furthermore, miR-186-5p inactivated the phosphatidylinositol 3-Kinase (PI3K)/mitogen-activated protein kinase (MAPK) signaling pathway by downregulating the expression of RAB27A/B, as shown in western blot analysis. Overall, miR-186-5p suppressed BCa cell proliferation, migration, invasion and EMT process and inhibited xenograft tumor growth by targeting RAB27A/B to inactivate the PI3K/MAPK signaling.

LINC01291 promotes hepatocellular carcinoma development by targeting miR-186-5p/OXSR1 axis

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Recent studies have demonstrated that lncRNAs play an important role in tumorigenesis. LINC01291 has been proven to be involved in the proliferation and migration of different cancers, but the function of LINC01291 in HCC is still unknown.

METHODS

First, the expression of LINC01291 in 50 paired HCC tissues, adjacent normal tissues and HCC cell lines was measured by qRT-PCR. Then, the function of LINC01291 in HCC cell proliferation, migration and invasion was measured by colony formation, Cell Counting Kit-8 (CCK8) assays, wound healing assays and Transwell assays. In addition, E-cadherin, N-cadherin, vimentin and OXSR1 protein expression levels were assessed via western blotting. Luciferase reporter assays were used to prove the relationship between LINC01291 and miR-186-5p as well as miR-186-5p and OXSR1 mRNA. Rescue assays and in vivo experiments further confirmed the LINC01291/miR-186-5p/OXSR1 axis in the progression of HCC.

RESULTS

LINC01291 was upregulated in both HCC tissues and cell lines. Knockdown of LINC01291 inhibited the proliferation, migration, invasion and EMT progression of HCC cells. In addition, LINC01291 could overexpress OXSR1 by sponging miR-186-5p, and OXSR1 overexpression or miR-186-5p inhibition could rescue the effect of LINC01291 knockdown in YY-8103 cell lines. In addition, lentiviral sh-LINC01291 could effectively inhibit the growth of subcutaneous YY-8103 xenograft tumors, while the anticancer effect could be reversed by cotransfection with in-miR-186-5p or ov-OXSR1.

CONCLUSIONS

LINC01291 can promote the proliferation, migration, invasion and EMT of HCC cells via the miR-186-5p/OXSR1 axis, and sh-LINC01291 can inhibit tumor growth in a xenograft mouse model.

Circular RNAcirc_0076305 Promotes Cisplatin (DDP) Resistance of Non-Small Cell Lung Cancer Cells by Regulating ABCC1 Through miR-186-5p

Background: Lung cancer is a social problem of increasing concern, and non-small cell lung cancer (NSCLC) accounts for 80%-85% incidence of lung cancer. Cisplatin (DDP) is reported as a first-line chemotherapy drug for NSCLC, but the resistance has became a main obstacle for NSCLC treatment. The high level of circular RNA circ_0076305 was related to the DDP resistance in NSCLC. However, the mechanism of circ_0076305 remains unclear in DDP resistance of NSCLC. Materials and Methods: Exosomes were detected by a transmission electron microscope and nanoparticle tracking analysis. The protein levels of CD63, CD81, P-glycoprotein (P-gp), Lung resistance-related protein, and ATP-binding cassette subfamily C member 1 (ABCC1) were examined by Western blot assay. Circ_0076305, microRNA-186-5p (miR-186-5p), and ABCC1 levels were tested by real-time quantitative polymerase chain reaction. DDP resistance was examined by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide assay. The binding relationship between miR-186-5p and circ_0076305 or ABCC1 was predicted by circRNA interactome or starBase, and then verified by dual-luciferase reporter and RNA immunoprecipitation assays. The effect of circ_0076305 on DDP resistance in NSCLC was examined by xenograft tumor model in vivo. Results: Circ_0076305 was increased in NSCLC cell-derived exosomes, DDP-resistant NSCLC tissues and cells. Circ_0076305 knockdown elevated DDP sensitivity in vitro. Mechanically, circ_0076305 enhanced ABCC1 expression through sponging miR-186-5p, thus regulating DDP resistance of NSCLC. Furthermore, circ_0076305 silencing improved DDP sensitivity of NSCLC in vivo. Conclusion: The results from this study disclosed that circ_0076305 knockdown improved DDP sensitivity by the miR-186-5p/ABCC1 axis in NSCLC, hinting a potential circRNA-targeted therapy for NSCLC.

Hsa_circ_0008360 sponges miR-186-5p to target CCND2 to modulate high glucose-induced vascular endothelial dysfunction

Vascular endothelial dysfunction is associated with the progress of many diseases. Circular RNAs (circRNAs) take part in the dysfunction of vascular endothelium. CircRNA hsa_circ_0008360 (circ_0008360) is dysregulated in high glucose-treated vascular endothelium, while the role and mechanism of circ_0008360 in high glucose-induced dysfunction remain unknown. Human umbilical vascular endothelium cells (HUVEC) were stimulated via high glucose. The abundances of circ_0008360, miR-186-5p and cyclin D2 (CCND2) were examined via quantitative real-time polymerase chain reaction or western blot. Vascular endothelial dysfunction was assessed via cell viability, apoptosis, migration and tube formation. The target relationship between miR-186-5p and circ_0008360 or CCND2 was analyzed via dual-luciferase reporter, RNA pull-down and RNA immunoprecipitation analyses. Circ_0008360 expression was enhanced in high-glucose-treated HUVEC. Circ_0008360 silence mitigated high glucose-induced suppression of viability, migration, tube formation, and increase in apoptosis in HUVEC. MiR-186-5p was sponged by circ_0008360, and miR-186-5p inhibition reversed the effect of circ_0008360 silence on high glucose-induced vascular endothelial dysfunction. MiR-186-5p alleviated high glucose-induced vascular endothelial dysfunction via targeting CCND2. CCND2 interference abolished the aggravated effect of circ_0008360 on high glucose-induced vascular endothelial dysfunction. Circ_0008360 knockdown attenuated high glucose-induced vascular endothelial dysfunction via regulating miR-186-5p and CCND2, indicating circ_0008360 might act as a target for the treatment of vascular endothelial dysfunction.Abbreviations: circRNAs, circular RNAs; HUVEC, human umbilical vascular endothelium cells; CCND2, cyclin D2; XPNPEP3, X-prolyl aminopeptidase 3; ceRNAs, competing endogenous RNAs; miRNAs, microRNAs; qRT-PCR, quantitative real-time polymerase chain reaction; RIP, RNA immunoprecipitation; HIF-1α, hypoxia inducible factor 1 alpha; TLR3, toll-like receptor 3; AKAP12, A-Kinase Anchoring Protein 12; ox-LDL, oxidized low-density lipoprotein; HG, high glucose; NG, normal glucose.

Long non-coding RNA ZFAS1 exerts a protective role to alleviate oxygen and glucose deprivation-mediated injury in ischemic stroke cell model through targeting miR-186-5p/MCL1 axis

In recent years, accumulating articles have revealed that long non-coding RNAs (lncRNAs) play crucial roles in ischemic stroke (IS). A previous study found that lncRNA zinc finger antisense 1 (ZFAS1) was down-regulated in IS patients compared with healthy controls. However, the precise function of ZFAS1 in IS and its associated mechanism remain unclear. Cell viability was assessed by cell counting kit-8 (CCK8) assay. Cell apoptosis was analyzed by flow cytometry. Western blot assay and quantitative real-time polymerase chain reaction (qRT-PCR) were conducted to measure protein and RNA expression. The interaction between microRNA-186-5p (miR-186-5p) and ZFAS1 or MCL1 apoptosis regulator, BCL2 family member (MCL1) was confirmed by dual-luciferase reporter assay, RNA-pull down assay and RNA immunoprecipitation (RIP) assay. IS cell model was established through exposing N2a cells to oxygen and glucose deprivation (OGD). OGD exposure restrained the viability and induced the apoptosis of N2a cells. OGD exposure down-regulated the expression of ZFAS1 and up-regulated the level of miR-186-5p in a time-dependent manner. ZFAS1 overexpression alleviated OGD-mediated injury in IS cell model. MiR-186-5p was identified as a direct target of ZFAS1, and OGD-induced injury in IS cell model was attenuated by the silence of miR-186-5p. MiR-186-5p interacted with the 3' untranslated region (3'UTR) of MCL1 messenger RNA (mRNA). ZFAS1 positively regulated MCL1 mRNA expression by sequestering miR-186-5p in N2a cells. ZFAS1 overexpression-mediated protective effects in IS cell model were partly overturned by the overexpression of miR-186-5p. MCL1 silencing partly counteracted the protective effects mediated by miR-186-5p silencing in IS cell model. In conclusion, ZFAS1 overexpression exerted a protective role in IS cell model to attenuate OGD-induced injury through targeting miR-186-5p/MCL1 axis. ZFAS1/miR-186-5p/MCL1 signaling might be a novel diagnostic marker and promising treatment target for IS patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10616-021-00481-4.

LncRNA HCP5 Induces Gastric Cancer Cell Proliferation, Invasion, and EMT Processes Through the miR-186-5p/WNT5A Axis Under Hypoxia

Objective

To experimentally determine the involvement and mechanism of long non-coding RNA (lncRNA) HCP5 in the development of gastric cancer (GC).

Methods

Detection of HCP5, miR-186-5p, and WNT5A expression in clinical GC tissues and adjacent healthy tissues was performed, followed by Pearson correlation analysis. BGC-823 and AGS cells, with interferences of HCP5, miR-186-5p, and WNT5A, were cultured under hypoxia. MTT, colony formation assay, Caspase-3 activity assay, and transwell assay were applied for the determination of cell proliferation, viability, apoptosis, and invasion, respectively. Expressions of WNT5A and protein markers of epithelial-mesenchymal transition (EMT) in cells were detected by western blotting. And the binding of HCP5 and WNT5A to miR-186-5p was validated using dual-luciferase reporter assay.

Results

In GC tissues, an increase in HCP5 and WNT5A expressions and a reduction in miR-186-5p expression were found, and the negative correlation between miR-186-5p and HCP5/WNT5A was proven. Subsequently, under hypoxia, an increase in HCP5 and WNT5A expressions and a decrease in miR-186-5p expression in GC cells were confirmed. In addition, in GC cells under hypoxia, the inhibition of HCP5 suppressed cell biological activity and EMT, while the inhibition of miR-186-5p or the overexpression of WNT5A led to the opposite changes.

Conclusion

An upregulation of WNT5A expression by HCP5 competitively binding to miR-186-5p promotes GC cell development.

Overexpression of lncRNA TUG1 Alleviates NLRP3 Inflammasome-Mediated Cardiomyocyte Pyroptosis Through Targeting the miR-186-5p/XIAP Axis in Coronary Microembolization-Induced Myocardial Damage

Coronary microembolization (CME) is a complicated problem that commonly arises in the context of coronary angioplasty. The lncRNA taurine-up regulated gene 1 (TUG1), significantly contributes to cardiovascular diseases; however, its contribution to CME-induced myocardial damage remains elusive. Herein, we establish the rat CME model and investigate the role of TUG1 in CME. The cell viability was evaluated via CCK-8 assay. Serum and cell culture supernatant samples were evaluated via ELISA. The dual luciferase reporter (DLR) assay, RIP, and RNA-pull down were conducted to validate the associations between TUG1 and miR-186-5p as well as miR-186-5p and XIAP. The expression of TUG1, miR-186-5p, and XIAP mRNA were determined by RT-qPCR, and proteins were evaluated via immuneblotting. As a result, TUG1 and XIAP were significantly down-regulated, and the miR-186-5p level was found to be remarkably up-regulated in CME myocardial tissues. Overexpression of TUG1 alleviated CME-induced myocardial injury and pyroptosis, whereas TUG1 knockdown showed the opposite effects. The DLR assay, RIP, and RNA-pull down results reveal that TUG1 directly targets miR-186-5p and miR-186-5p directly targets XIAP. In vitro rescue experiments show that TUG1 overexpression alleviates LPS-caused cardiomyocyte injury and pyroptosis via sponging miR-186-5p and regulating XIAP, and depression of miR-186-5p reduces LPS-induced cardiomyocyte injury and pyroptosis by targeting XIAP. Concludingly, the overexpression of TUG1 alleviates NLRP3 inflammasome-mediated cardiomyocyte pyroptosis through targeting the miR-186-5p/XIAP axis in CME-induced myocardial injury.

Circ_0068087 Silencing Ameliorates Oxidized Low-Density Lipoprotein-Induced Dysfunction in Vascular Endothelial Cells Depending on miR-186-5p-Mediated Regulation of Roundabout Guidance Receptor 1

Background: Circular RNAs (circRNAs) are endogenous non-coding RNAs involved in the progression of atherosclerosis (AS). We investigated the role of circ_0068087 in AS progression and its associated mechanism.

Methods: The 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay, flow cytometry, and enzyme-linked immunosorbent assay (ELISA) were performed to analyze the viability, apoptosis, and inflammatory response of HUVECs, respectively. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and the Western blot assay were performed to measure the expression of RNA and protein. Cell oxidative stress was analyzed using commercial kits. The dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to verify the interaction between microRNA-186-5p (miR-186-5p) and circ_0068087 or roundabout guidance receptor 1 (ROBO1).

Results: Oxidized low-density lipoprotein (ox-LDL) exposure upregulated the circ_0068087 level in HUVECs. ox-LDL-induced dysfunction in HUVECs was largely attenuated by the silence of circ_0068087. Circ_0068087 negatively regulated the miR-186-5p level by interacting with it in HUVECs. Circ_0068087 knockdown restrained ox-LDL-induced injury in HUVECs partly by upregulating miR-186-5p. ROBO1 was a downstream target of miR-186-5p in HUVECs. Circ_0068087 positively regulated ROBO1 expression by sponging miR-186-5p in HUVECs. MiR-186-5p overexpression exerted a protective role in ox-LDL-induced HUVECs partly by downregulating ROBO1.

Conclusion: Circ_0068087 interference alleviated ox-LDL-induced dysfunction in HUVECs partly by reducing ROBO1 expression via upregulating miR-186-5p.

LncRNA HCP5 promotes neuroblastoma proliferation by regulating miR-186-5p/MAP3K2 signal axis

INTRODUCTION

Neuroblastoma (NB) is the most common solid tumor in children. Studies showed that long-chain noncoding RNA (lncRNA) HCP5 played an important role in tumorigenesis, but its role in NB remained unclear. This study aims to determine the role of HCP5 in NB and its possible molecular mechanism.

METHODS

We analyzed the expression levels of miRNA-186-5p and HCP5 in neuroblastoma and neuroblastoma cell lines SHSY-5Y, Kelly, NBL-S and SK-N-AS, and explored their roles.

RESULTS

We found that the HCP5 expression was up-regulated in NB tissues and cells. The higher the HCP5 expression in NB cells, the stronger the ability of clone formation. Down regulation of the HCP5 expression inhibited the proliferation of NB cells and the growth of subcutaneous transplanted tumor in nude mice. HCP5 could competitively bind miR-186-5p, while miR-186-5p could target the 3'-UTR of MAP3K2. The expression level of miR-186-5p was down regulated while the expression level of MAP3K2 was up-regulated in NB tissues. The expression level of HCP5 and miR-186-5p, the expression level of miR-186-5p and MAP3K2 were negatively correlated. The decreased proliferation of NB cells induced by down-regulation of HCP5 expression can be counteracted by miR-186-5p inhibitor or MAP3K2, and vice versa.

CONCLUSION

This study showed that lncRNA HCP5, as ceRNA, regulated MAP3K2 to promote NB progression through competitive binding of miR-186-5p. We revealed a new signaling pathway that mediates NB, which provided a new target for the diagnosis and treatment of NB.

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.

MicroRNA profiling identifies Forkhead box transcription factor M1 (FOXM1) regulated miR-186 and miR-200b alterations in triple negative breast cancer

Breast cancer (BC) is the most commonly diagnosed malignancy. MicroRNAs (miRNAs) play important roles in the tumorigenesis, metastasis and progression of BC. Forkhead Box M1 (FOXM1) oncogenic transcription factor is involved in events considered as hallmarks of cancer. However, the specific mechanism by which FOXM1 exerts its oncogenic effects remains unclear and little is known about its effects on the regulation of miRNA expression. We have found that FOXM1 is upregulated in breast cancer cells and that its expression is associated with shortened overall survival and poor prognosis in patients with BC. Using microarray technology, we assessed the expression profiles of 752 miRNAs in highly aggressive and metastatic triple negative breast cancer (TNBC) cells in response to FOXM1 knockdown and identified 13 differentialy expressed miRNAs (3 miRNAs upregulated and 10 miRNAs down-regulated). We validated the results of the miRNA expression profile in two different TNBC cells by performing qRT-PCR and identified that miR-186-5p and miR-200b-5p were consistently down- or up-regulated, respectively, after knockdown of FOXM1. We further performed KEGG pathway analysis and GO enrichment analysis for miR-186-5p and miR-200b-5p, and identified that these miRNAs are associated with cancer development and progression involving toll-like receptor signaling, cell cycle, AMPK, p53 and NF-kappa B signaling pathways. Taken together, our results suggest that increased FOXM1 expression is associated with poor patient survival and leads to induction of oncomiR miR-186-5p expression and tumor-suppressor inhibition miR-200b-5p, suggesting that the FOXM1/miRNA signaling pathway may contribute to poor patient prognosis and may be a potential therapeutic target in TNBC.

Regulation of miR-186-YY1 axis by the p53 translational isoform ∆40p53: implications in cell proliferation

We have earlier shown that p53-FL and its translational isoform ∆40p53 are differentially regulated. In this study, we have investigated the cellular effect of ∆40p53 regulation on downstream gene expression, specifically miRNAs. Interestingly, ∆40p53 showed antagonistic regulation of miR-186-5p as compared to either p53 alone or a combination of both the isoforms. We have elucidated the miR-186-5p mediated effect of ∆40p53 in cell proliferation. Upon expression of ∆40p53, we observed a significant decrease in YY1 levels, an established target of miR-186-5p, which is involved in cell proliferation. Further assays with anti-miR-186 established the interdependence of ∆40p53- miR-186-5p-YY1- cell proliferation. The results unravel a new dimension toward the understanding of ∆40p53 functions, which seems to regulate cellular fate independent of p53FL.

Targeting SNHG3/miR-186-5p reverses the increased m6A level caused by platinum treatment through regulating METTL3 in esophageal cancer

Background

Platinum-based chemotherapy is a mainstay for treating esophageal cancer patients. In this manuscript, we have provided clues for influence of platinum on overall m6A level and further investigated the potential regulatory mechanism.

Methods

qRT-PCR was used to measure SNHG3 and miR-186-5p expression; ELISA and western blot were used to measure the expression of METTL3. CCK8 was used to measure the cell proliferation rate. Caspase 3/7 activity was used to measure the apoptosis rate. Dual luciferase reporter gene assay and RNA pull down assay were used to investigate the potential crosstalk between miR-186-5p and SNHG3; and miR-186-5p and METTL3.

Results

m6A level was increased when treated with platinum (CDDP, CPB and L-OHP). Besides, SNHG3 expression was induced and miR-186-5p expression was suppressed by platinum. Furthermore, SNHG3 could promote the m6A level, however miR-186-5p inhibited the m6A level through targeting METTL3. SNHG3 interacts with miR-186-5p to negatively regulate the expression of miR-186-5p; and miR-186-5p might bind to the 3′UTR of METTL3 to regulate its expression.

Conclusion

Platinum can increase the overall m6A level of esophageal cancer. SNHG3/miR-186-5p, induced by platinum, was involved in regulating m6A level by targeting METTL3. Our manuscript has provided clues that regulating m6A level might be a novel way to enhance the platinum efficacy.

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.

Up-regulating lncRNA OIP5-AS1 protects neuron injury against cerebral hypoxia-ischemia induced inflammation and oxidative stress in microglia/macrophage through activating CTRP3 via sponging miR-186-5p

BACKGROUND

Inflammation and oxidative stress is closely associated with the development of ischemic brain stroke. Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1), a novel identified long non-coding RNA (lncRNA), has been suggested to play an important role in the development of many types of human cancers. However, the functional involvement of OIP5-AS1 in ischemic stroke is still unknown.

METHODS

Quantitative real-time polymerase chain reaction and /or western blot were conducted to determine the expression profiles of OIP5-AS1, C1q/TNF-related protein 3 (CTRP3) and miR-186-5p in the serum of stroke patients, as well as in the ischemic penumbra of rats with middle cerebral artery occlusion/reperfusion (MCAO/R) injury and microglial cells treated with oxygen glucose deprivation/re-oxygenation (OGD/R). Upon selective regulation of OIP5-AS1 and miR-186-5p, the inflammation and oxidative stress responses in microglia/macrophage as well as neurologic functions in MCAO/R rats were detected. Furthermore, the interactions between OIP5-AS1 and miR-186-5p, miR-186-5p and CTRP3 were investigated by RNA immunoprecipitation (RIP) assay, luciferase report assay and bioinformation anaylsis.

RESULTS

We observed markedly increased infarct volume, neuronal apoptosis, inflammation and oxidative stress responses in the infarcted lesions of MCAO/R rats, in line with down-regulated levels of OIP5-AS1 and CTRP3 while up-regulated miR-186-5p. Functional studies demonstrated that up-regulation of OIP5-AS1 attenuated infarct volume, neuronal apoptosis, microglia/macrophage inflammation and oxidative stress responses induced by MCAO/R or OGD/R. In terms of mechanism, we revealed that OIP5-AS1-miR-186-5p-CTRP3 axis played a vital role in modulating microglia/macrophage activation and neuronal apoptosis.

CONCLUSION

Up-regulating lncRNA OIP5-AS1 protects neuron injury against MCAO/R induced inflammation and oxidative stress in microglia/macrophage through activating CTRP3 via sponging miR-186-5p.

Long noncoding RNA SNHG14 regulates ox-LDL-induced atherosclerosis cell proliferation and apoptosis by targeting miR-186-5p/WIPF2 axis

To investigate the role of small nucleolus RNA host gene 14 (SNHG14) in the progression of atherosclerosis (AS), bioinformatics analysis, and other relevant experiments (cell counting kit-8, flow cytometry, quantitative real-time polymerase chain reaction, luciferase reporter, RNA immunoprecipitation, RNA pull-down, and western blot assays) were done. The current study revealed that SNHG14 level was high in the serum of AS patients and oxidized low-density lipoprotein (ox-LDL)-induced AS cell lines. Besides, we found that SNHG14 accelerated cell proliferation while inhibited cell apoptosis in ox-LDL-induced AS cell lines. Next, SNHG14 was confirmed to be a sponge for miR-186-5p in AS cells, and it was validated that SNHG14 regulated AS cell proliferation and apoptosis by sponging miR-186-5p. Moreover, we uncovered that WAS-interacting protein family member 2 (WIPF2) was a downstream target of miR-186-5p in AS cells. Finally, it was demonstrated that miR-186-5p modulated AS cell proliferation and apoptosis via targeting WIPF2. To conclude, our research disclosed that SNHG14 affected ox-LDL-induced AS cell proliferation and apoptosis through miR-186-5p/WIPF2 axis, which may provide a theoretical basis for the treatment and diagnosis of AS.

LncRNA TUG1 facilitates proliferation, invasion and stemness of ovarian cancer cell via miR-186-5p/ZEB1 axis

LncRNA TUG1 has been rarely studied in ovarian cancer (OC), our objective was to explore the role of TUG1 in the regulation of malignant phenotypes of OC. Vectors of sh-TUG1, miR-186-5p and pcDNA-ZEB1 were, respectively, constructed and used to infect OC cells. MTT and transwell assays were applied for representing cell proliferation and invasion, respectively. Sphere formation experiment was used to detect the stemness of OC cells. Western blotting and qRT-PCR were employed for detecting the expression of multiple biomarkers on protein and RNA levels, respectively. The luciferase assay was performed to reveal the interactions between miR-186-5p and TUG1 or ZEB1. The silencing of TUG1 and upregulation of miR-186-5p both suppressed the cell proliferation, invasion and cancer stem cell (CSC) properties. Additionally, luciferase assay verified that miR-186-5p directly binds TUG1 and ZEB1. Moreover, overexpression of ZEB1 rescued the impact on the proliferation, invasion and stemness of TUG1 silencing in OC. TUG1 sponges miR-186-5p to release ZEB1 and promotes the proliferation, invasion and stemness of OC cells, suggesting that TUG1 could be a potential therapeutic target for OC therapy. SIGNIFICANCE OF THE STUDY: LncRNA TUG1 could promote proliferation, invasion and stemness of ovarian cancer cells. Our study first discovered that TUG1 play a tumourigenic role in ovarian cancer by regulating stemness of cancer cells. Mechanism research exhibited the regulation role of TUG1 in ovarian cancer cells was miR-186-5p/ZEB1 axis depended. These results provided a new perspective to understand the pathogenesis and development of ovarian cancer; it will offer new evidence for better diagnosis and treatment therapy of ovarian cancer.

Silencing of Long Noncoding RNA SNHG6 Inhibits Esophageal Squamous Cell Carcinoma Progression via miR-186-5p/HIF1α Axis

AIMS

Long noncoding RNA (lncRNA) small nucleolar RNA host gene 6 (SNHG6) has been shown to be upregulated in esophageal squamous cell carcinoma (ESCC). However, its detailed function in ESCC remains unknown. We investigated its specific roles in ESCC cell proliferation, invasion, and migration.

METHODS

Gene expression was evaluated by quantitative reverse transcriptase polymerase chain reaction and western blot. The subcellular localization of lncRNA SNHG6 was determined using subcellular location assay. Luciferase reporter assay and RNA pull-down assay were applied to determine the interaction between lncRNA SNHG6, miR-186-5p, and hypoxia-inducible factor 1α (HIF1α). The cell proliferation, migration, and invasion abilities were evaluated by using cell count kit-8, colony formation assay, and transwell migration and invasion assays.

RESULTS

LncRNA SNHG6 and HIF1α were upregulated, while miR-186-5p was downregulated in ESCC tissues and cell lines. Knockdown of lncRNA SNHG6 inhibits ESCC cell proliferation, migration, and invasion. A negative correlation between lncRNA SNHG6 and miR-186-5p expression was found in ESCC tissues. Similarly, there is a positive correlation between lncRNA SNHG6 and HIF1α expression in ESCC tissues. Conversely, miR-186-5p expression was negatively correlated with HIF1α expression in ESCC tissues. Furthermore, lncRNA SNHG6 was identified as a decoy for miR-186-5p, thereby promoting the expression of miR-186-5p target HIF1α. More significantly, restoration of SNHG6 or HIF1α could reverse the inhibitory effect of miR-186-5p on ESCC cell proliferation, migration, and invasion.

CONCLUSIONS

Downregulation of SNHG6 inhibited the proliferation, migration, and invasion of ESCC cells through regulating miR-186-5p/HIF1α axis, providing a novel therapeutic target for ESCC.

DSCAM-AS1 accelerates cell proliferation and migration in osteosarcoma through miR-186-5p/GPRC5A signaling

Osteosarcoma (OS) is one of the most primary bone malignancies, often occurring in adolescents or children. Numerous scientific findings have introduced that long noncoding RNAs (lncRNAs) can be involved in tumor occurrence and development. Although DSCAM-AS1 has been studied in several cancers, its role and mechanism in OS are poorly understood. In this work, high level of DSCAM-AS1 was validated in OS cell lines. Depleting DSCAM-AS1 inhibited cell proliferation, migration and EMT process in OS. Subsequently, we disclosed that DSCAM-AS1 was mainly observed in the cytoplasm of OS cells and could bind with miR-186-5p in OS. Moreover, inhibiting miR-186-5p rescued the impact of silenced DSCAM-AS1 on OS progression. Additionally, GPRC5A was verified as the target downstream of miR-186-5p, and it was negatively modulated by miR-186-5p but positively regulated by DSCAM-AS1. More importantly, DSCAM-AS1 enhanced GPRC5A level in OS by sequestering miR-186-5p. Finally, up-regulating GPRC5A reversed the influences of DSCAM-AS1 repression on the oncogenic behaviors of OS cells. Knockdown of DSCAM-AS1 suppressed NPC tumor growth in vivo. All findings uncovered that DSCAM-AS1 aggravated OS progression through sponging miR-186-5p to up-regulate GPRC5A expression. Thus, we proposed DSCAM-AS1 as a probable target for OS treatment.

circ-NRIP1 Promotes Glycolysis and Tumor Progression by Regulating miR-186-5p/MYH9 Axis in Gastric Cancer

Background

Gastric cancer (GC) is a severe threat to human life, with high incidence and mortality. Circular RNAs (circRNAs) play crucial roles in the progression of GC. This study attempted to investigate the potential role of circ-NRIP1 and associated action mechanisms in GC cells.

Methods

The expression of circ-NRIP1 and miR-186-5p was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability, apoptosis, and migration were assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, flow cytometry assay, and transwell assay, respectively. Cellular glycolysis, including cellular glucose uptake, lactate, and ATP/ADP ratios, was also detected by commercial assay kits. The protein levels of hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2) were quantified by Western blot. The relationship between miR-186-5p and circ-NRIP1 or myosin heavy chain 9 (MYH9) was predicted by the online bioinformatics tool, starBase, and verified by dual-luciferase reporter assay. Xenograft tumor model was used to evaluate biological function in vivo.

Results

The expression of circ-NRIP1 was up-regulated in tissues of GC patients and cells, as well as negatively associated with that of miR-186-5p in tissues. circ-NRIP1 knockdown inhibited cell proliferation, migration, and glycolysis, but induced apoptosis in HGC-27 and AGS cells. circ-NRIP1 competitively targeted miR-186-5p, and MYH9 was a target of miR-186-5p. miR-186-5p knockdown inverted the bio-function effects and glycolytic activation from circ-NRIP1 silencing in HGC-27 and AGS cells. Meanwhile, MYH9 overexpression could rescue the effects of miR-186-5p. Besides, miR-186-5p knockdown inverted the expression pattern of si-circ-NRIP1 transfection in GC cells. Additionally, in vivo experiments confirmed that sh-circ-NRIP1 inhibited tumor growth.

Conclusion

circ-NRIP1 accelerated the glycolysis and GC progression by modulating MYH9 via miR-186-5p, suggesting that circ-NRIP1 was a promising biomarker for the treatment of GC.

MORC2 promotes cell growth and metastasis in human cholangiocarcinoma and is negatively regulated by miR-186-5p

Microrchidia family CW-type zinc finger 2 (MORC2) is a ubiquitously expressed protein that contributes to chromatin remodeling, DNA repair, and lipogenesis. However, its role in cholangiocarcinoma (CCA) remains largely unknown. The aim of this study was to investigate the expression profile of MORC2 and its potential functions in CCA progression. The results showed that MORC2 was upregulated in human CCA specimens and cell lines. MORC2 expression was significantly associated with serum CA19-9 levels (P = 0.009), TNM stage (P = 0.003) and lymph node invasion (P = 0.004). Furthermore, high MORC2 expression was associated with poor 5-year survival (P = 0.016). Functional experiments revealed that MORC2 knockdown could suppress CCA cell proliferation, migration, and invasion both in vivo and in vitro. Mechanically, we found that MORC2 promoted CCA cell metastasis through the EMT process and enhanced proliferation via the Akt signaling pathway. Moreover, MORC2 was negatively regulated by miR-186-5p. MiR-186-5p could influence CCA cell proliferation, migration and metastasis by regulating MORC2. Taken together, the findings of this study demonstrated the oncogenic role of MORC2 in CCA tumorigenesis and metastasis, and clarified an underlying regulatory mechanism mediating MORC2 upregulation, which may provide a novel therapeutic target in CCA treatment.

Silencing circular RNA circZNF609 restrains growth, migration and invasion by up-regulating microRNA-186-5p in prostate cancer

Background: Prostate cancer (PC) fearfully impacts men's health. We explored the efficacy and mechanism of circular RNA circZNF609 (circZNF609) on colony formation, viability, apoptosis, migration and invasion and in PC cells. Methods: Colony formation, CCK-8, flow cytometry, migration and invasion assay were respectively used to detect the functions of circZNF609 and microRNA (miR)-186-5p on cell colony ability, viability, apoptosis, migration and invasion. circZNF609 and miR-186-5p expression were changed by cell transfection and tested by RT-qPCR. Moreover, Cleaved-Caspase-3, Cleaved-Caspase-9, matrix metalloproteinase-9 (MMP-9), Vimentin and relate-proteins of cell pathways were examined through Western blot. Results: circZNF609 was highly expressed at PC tissues. circZNF609 declined cell colony ability, viability, migration and invasion and caused apoptosis. Furthermore, circZNF609 negatively regulated miR-186-5p, miR-186-5p inhibitor could reverse impacts of circZNF609. Finally, circZNF609 restrained the YAP1 and AMPK pathways by up-regulating miR-186-5p. Conclusion: Silencing circZNF609 restrained growth, migration and invasion of PC cells by up-regulating miR-186-5p via YAP1 and AMPK pathways. Highlights circZNF609 is highly expressed in PC tissues; circZNF609 restrains cell growth, migration and invasion; circZNF609 exerts its function by up-regulating miR-186-5p; circZNF609 exerts its function by YAP1 and AMPK signaling pathways.

Long Intergenic Non-Protein Coding RNA 665 Regulates Viability, Apoptosis, and Autophagy via the MiR-186-5p/MAP4K3 Axis in Hepatocellular Carcinoma

PURPOSE

Long intergenic non-protein coding RNA 665 (LINC00665) plays a vital role in the development of cancer. Its function in hepatocellular carcinoma (HCC), however, remains largely unknown.

MATERIALS AND METHODS

The expressions of LINC00665, miR-186-5p, and MAP4K3 were determined by qRT-PCR. Cell viability and apoptosis were evaluated by MTT and flow cytometry, respectively. Autophagic puncta formation was observed by fluorescence microscopy. Bioinformatics analysis, luciferase reporter assay, RNA immunoprecipitation, and RNA pulldown were performed to identify associations among LINC00665, miR-186-5p, and MAP4K3. Western blot was utilized to examine the expressions of MAP4K3, Beclin-1, and LC3. Tumor growth was evaluated in a xenograft model.

RESULTS

Elevations in LINC00665 were observed in HCC tissues and cells. The overall survival of HCC patients with high levels of LINC00665 was shorter than those with low levels. In vitro, LINC00665 depletion inhibited viability and induced apoptosis and autophagy. miR-186-5p interacted with LINC00665 and was downregulated in HCC tissues and cells. Upregulation of miR-186-5p inhibited viability and induced apoptosis and autophagy, which were attenuated by upregulation of LINC00665. MAP4K3 was found to possess binding sites with miR-186-5p and was upregulated in HCC tissues and cells. MAP4K3 depletion inhibited viability and induced apoptosis and autophagy, which were attenuated by miR-186-5p inhibitor. In vivo, miR-186-5p expression was negatively correlated with LINC00665 or MAP4K3 in HCC tissues, while LINC00665 was positively correlated with MAP4K3. LINC00665 knockdown suppressed tumor growth.

CONCLUSION

LINC00665 was involved in cell viability, apoptosis, and autophagy in HCC via miR-186-5p/MAP4K3 axis, which may provide a new approach for HCC treatment.

The lncRNA-DLEU2/miR-186-5p/PDK3 axis promotes the progress of glioma cells

Long non-coding RNAs (lncRNAs) have great value in research on tumour targeted therapy, including for glioma. In the present study, we investigated the role of the lncRNA deleted in lymphocytic leukaemia 2 (lncRNA-DLEU2) in glioma. First, we found that lncRNA-DLEU2 is highly expressed in glioma tissues and cell lines. Next, experiments in cells showed that lncRNA-DLEU2 knockdown inhibited, whereas lncRNA-DLEU2 overexpression promoted, the clone formation, migration and invasion of glioma cells. A luciferase reporter assay and an RNA immunoprecipitation assay demonstrated that lncRNA-DLEU2 acts as a sponge for miR-186-5p in glioma cells. Further, studies suggested that miR-186-5p inhibits the expression of PDK3, which is an oncogene in glioma. Moreover, with rescue experiments, we demonstrated that lncRNA-DLEU2 regulates the expression of PDK3 and the progression of glioma in a miR-186-5p-dependent manner. Finally, we also showed that lncRNA-DLEU2 promotes glioma growth in a manner that is related to miR-186-5p and PDK3 in vivo. In conclusion, our study reported for the first time that lncRNA-DLEU2 promotes glioma progression by targeting the miR-186-5p/PDK3 axis. These findings provide novel strategies for the gene therapy treatment of glioma.

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

OBJECTIVE

To explore the expression of miR-186-5p in lung adenocarcinoma (LUAD) and its possible function associated with cancer cell proliferation, migration and invasion.

METHODS

MiR-186-5p expression levels in LUAD samples, human LUAD cell lines H1299 and NCI-H1975, and normal human lung epithelial cell line BEAS-IB were assessed by quantitative real-time PCR (qRT-PCR). H1299 and NCI-H1975 cells were transfected with miR-186-5p mimic or miRNA negative control. CCK-8 assay was performed to evaluate the cell proliferation. Transwell assay and transwell-matrigel™ invasion assay were applied to assess the migration and invasion abilities of H1299 and NCI-H1975 cells.

RESULTS

miR-186-5p expression was significantly up-regulated in LUAD tumor tissues and LUAD cell lines as compared with tumor-adjacent tissues and normal human lung epithelial cells, respectively. MiR-186-5p overexpression remarkably promoted the proliferation, migration and invasion of LUAD cells. Furthermore, phosphatase and tensin homolog (PTEN) was a direct target of miR-186-5p verified by luciferase reporter assay. Overexpression of PTEN significantly suppressed LUAD cells to proliferate, migrate and invade. MiR-186-5p overexpression-induced LUAD cell phenotype could be partially rescued by co-overexpression of miR-186-5p and PTEN.

CONCLUSION

This study demonstrated that miR-186-5p is up-regulated in LUAD, and functionally associated with cell proliferation, migration and invasion. MiR-186-5p promotes the proliferation, migration and invasion of LUAD cells by targeting PTEN. MiR-186-5p may be utilized as a novel molecular marker and therapeutic target of LUAD.

miR-186-5p Functions as a Tumor Suppressor in Human Osteosarcoma by Targeting FOXK1

BACKGROUND/AIMS

Aberrantly expressed miRNAs play a vital role in the development of some cancers, such as human osteosarcoma (OS). However, the detailed molecular mechanisms underlying miR-186-5p-involved osteosarcoma are unclear.

METHODS

qRT-PCR and western blot analysis were employed to measure the expressions of miR-186-5p and forkhead box k1 (FOXK1). CCK-8 assay evaluated the effect of miR-186-5p and FOXK1 on cell proliferation. Transwell assay confirmed cell migration and invasion. Eventually, the dual-luciferase reporter assay validated 3'-untranslated region (3'-UTR) of FOXK1 as a direct target of miR-186-5p.

RESULTS

Down-regulation of miR-186-5p was identified in OS tissues and cell lines, and negatively correlated with distant metastasis, Enneking stage and poor 5-year prognosis as well as the expression of forkhead box k1 (FOXK1) protein. Further assays demonstrated that miR-186-5p overexpression had inhibitory effects on in-vitro cell proliferation, cell cycle, and in-vivo tumor growth. miR-186-5p overexpression also inhibited the epithelial-tomesenchymal transition (EMT), migration and invasion of OS cells. Importantly, miR-186-5p directly targeted FOXK1 3'-UTR and negatively regulated its expression. Silencing of FOXK1 expression enhanced the inhibitory effects of miR-186-5p on OS cell proliferation, migration and invasion.

CONCLUSION

These findings highlighted miR-186-5p as a tumor suppressor in the regulation of progression and metastatic potential of OS, and may benefit the development of therapies targeting miR-186-5p in patients with OS.

HOXD-AS1 promotes the epithelial to mesenchymal transition of ovarian cancer cells by regulating miR-186-5p and PIK3R3

Background

Epithelial ovarian cancer (EOC) is one of the most malignant gynecological tumors worldwide. Deregulation of long non-coding RNAs (lncRNAs) has been implicated in various oncogenic processes in multiple cancers. In this study, we aim to identify and characterize clinically relevant lncRNA deregulation in EOC.

Methods

LncRNAs, mRNAs and miRNAs were profiled using expression microarrays and validated using reverse transcription quantitative PCR in EOC cells and tissues. siRNAs targeting either HOXD-AS1 or PIK3R3 together with miR-186-5p inhibitors were used to modulate endogenous target expression in EOC cell lines in vitro. In vitro wound healing assay, trans-well assay, Western-blot assay,and Dual-luciferase reporter assay were used to explore the biological roles and molecular function underlying HOXD-AS1 in the EOC cells. Progression-free survival (PFS) and overall survival (OS) were statistically analyzed by Kaplan-Meier method test.

Results

HOXD-AS1 was found to be significantly over-expressed in EOC tumors. High HOXD-AS1 expression significantly correlated with poorer PFS and OS of EOC patients. Multivariate Cox proportional hazards modeling indicated that HOXD-AS1 was an independent risk predictor of EOC patients (HR = 1.92, p = 0.004). SiRNA inhibition of HOXD-AS1 reduced cell migration, invasion, and epithelial-mesenchymal transition (EMT) in EOC cells in vitro by preventing HOXD-AS1 directly binding to miR-186-5p, and resulting in down-regulating of PIK3R3. The novel HOXD-AS1/miR-186-5p/PIK3R3 pathway was clinically relevant as we observed a significantly inverse correlation between HOXD-AS1/miR-186-5p and between miR-186-5p/PIK3R3 in an independent cohort of 200 EOC tissues.

Conclusions

HOXD-AS1/miR-186-5p/PIK3R3 is a novel pathway to promote cell migration, invasion, and EMT in EOC.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1103-5) contains supplementary material, which is available to authorized users.

MicroRNA-186-5p controls GluA2 surface expression and synaptic scaling in hippocampal neurons

Homeostatic synaptic scaling is a negative feedback response to fluctuations in synaptic strength induced by developmental or learning-related processes, which maintains neuronal activity stable. Although several components of the synaptic scaling apparatus have been characterized, the intrinsic regulatory mechanisms promoting scaling remain largely unknown. MicroRNAs may contribute to posttranscriptional control of mRNAs implicated in different stages of synaptic scaling, but their role in these mechanisms is still undervalued. Here, we report that chronic blockade of glutamate receptors of the AMPA and NMDA types in hippocampal neurons in culture induces changes in the neuronal mRNA and miRNA transcriptomes, leading to synaptic upscaling. Specifically, we show that synaptic activity blockade persistently down-regulates miR-186-5p. Moreover, we describe a conserved miR-186-5p-binding site within the 3'UTR of the mRNA encoding the AMPA receptor GluA2 subunit, and demonstrate that GluA2 is a direct target of miR-186-5p. Overexpression of miR-186 decreased GluA2 surface levels, increased synaptic expression of GluA2-lacking AMPA receptors, and blocked synaptic scaling, whereas inhibition of miR-186-5p increased GluA2 surface levels and the amplitude and frequency of AMPA receptor-mediated currents, and mimicked excitatory synaptic scaling induced by synaptic inactivity. Our findings elucidate an activity-dependent miRNA-mediated mechanism for regulation of AMPA receptor expression.