CircUGGT2 downregulation by METTL14-dependent m6A modification suppresses gastric cancer progression and cisplatin resistance through interaction with miR-186-3p/MAP3K9 axis.

Chemoresistance is a major therapeutic challenge in advanced gastric cancer (GC). N6-methyladenosine (m6A) RNA modification has been shown to play fundamental roles in cancer progression. However, the underlying mechanisms by which m6A modification of circRNAs contributes to GC and chemoresistance remain unknown. We found that hsa_circ_0030632 (circUGGT2) was a predominant m6A target of METTL14, and METTL14 knockdown (KD) reduced circUGGT2 m6A levels but increased its mRNA levels. The expression of circUGGT2 was markedly increased in cisplatin (DDP)-resistant GC cells. CircUGGT2 KD impaired cell growth, metastasis and DDP-resistance in vitro and in vivo, but circUGGT2 overexpression prompted these effects. Furthermore, circUGGT2 was validated to sponge miR-186-3p and upregulate MAP3K9 and could abolish METTL14-caused miR-186-3p upregulation and MAP3K9 downregulation in GC cells. circUGGT2 negatively correlated with miR-186-3p expression and harbored a poor prognosis in patients with GC. Our findings unveil that METTL14-dependent m6A modification of circUGGT2 inhibits GC progression and DDP resistance by regulating miR-186-3p/MAP3K9 axis.

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.

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.

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.

miR-186-5p targets TGFßR2 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-ß type II receptor (TGFßR2) 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 TGFßR2/Smad2/p38 molecular axes, thus providing a promising new pro-repair drug target.

Circular RNA circ_0008305 aggravates hepatocellular carcinoma growth through binding to miR-186 and inducing TMED2.

Dysregulation of circRNAs is reported to exert crucial roles in cancers, including hepatocellular carcinoma (HCC). So far, the function of circRNAs in HCC development remains poorly known. Currently, our data showed that circ_0008305 was highly elevated in HCC cell lines and 30 paired tissue samples of HCC. As evidenced, suppression of circ_0008305 repressed HCC cell growth significantly. Meanwhile, up-regulation of circ_0008305 significantly reduced HCC cell growth. Mechanistically, we displayed that circ_0008305 could bind with miR-186 by using bioinformatics analysis. miR-186 has been reported to be a crucial tumour oncogene in many cancers. In addition, we proved miR-186 was greatly decreased in HCC. The direct correlation between miR-186 and circ_0008305 was confirmed in our work. In addition, up-regulation of miR-186 obviously restrained HCC progression. Increased expression of transmembrane p24 trafficking protein 2 (TMED2) is significantly related to the unfavourable outcomes in cancer patients. At our present work, we proved that TMED2 could act as a direct target of miR-186. Mechanistically, we demonstrated that circ_0008305 up-regulated TMED2 expression by sponging miR-186, which resulted in significantly induced HCC progression in vitro and in vivo. These revealed the significant role of circ_0008305 in HCC progression, which might indicate a new perspective on circRNAs in HCC development.

Extracellular vesicle-mediated transfer of lncRNA CLDN10-AS1 aggravates low-density lipoprotein-induced vascular endothelial injury.

Oxidized low-density lipoprotein (ox-LDL) stimulation impairs the oxidation-reduction equilibrium in vascular endothelial cells (VECs) and contributes to atherosclerosis (AS). This study probed the mechanisms of extracellular vesicle (EV)-mediated transfer of lncRNA CLDN10 antisense RNA 1 (CLDN10-AS1) in ox-LDL-induced VEC injury. Initially, VEC injury models were established by treating human umbilical vein endothelial cells (HUVECs) with ox-LDL. EVs were isolated from HUVECs (HUVECs-EVs) and identified. CLDN10-AS1, microRNA (miR)-186, and Yin Yang 1 (YY1) expressions in ox-LDL-treated HUVECs and EVs derived from these cells (ox-EVs) were measured. HUVECs were incubated with EVs, after which the cell viability, apoptosis, and concentrations of proinflammatory cytokines and oxidative stress markers were measured. We discovered that CLDN10-AS1 and YY1 were upregulated in ox-LDL-treated HUVECs, whereas miR-186 was downregulated. ox-EVs treatment elevated CLDN10-AS1 expression in HUVECs and ox-EVs overexpressing CLDN10-AS1 promoted VEC injury. Besides, CLDN10-AS1 is competitively bound to miR-186 and promoted YY1 expression. Rescue experiments revealed that miR-186 overexpression or YY1 suppression partially reversed the roles of ox-EVs overexpressing CLDN10-AS1 in ox-LDL-induced VEC injury. Lastly, clinical serum samples were collected for verification. Overall, CLDN10-AS1 carried by HUVECs-EVs into HUVECs competitively bound to miR-186 to elevate YY1 expression, thereby aggravating ox-LDL-induced VEC injury.

LINC01291 promotes hepatocellular carcinoma development by targeting the 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 confirmed to be involved in the proliferation and migration of different cancers, although 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 a quantitative real-time polymerase chain reaction. Then, the function of LINC01291 in HCC cell proliferation, migration and invasion was measured by colony formation, Cell Counting Kit-8 assays, wound healing assays and transwell assays. In addition, E-cadherin, N-cadherin, vimentin and oxidative stress-responsive 1 (OXSR1) protein expression levels were assessed via western blotting. Luciferase reporter assays were used to confirm 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 epithelial-mesenchymal progression (EMT) 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, whereas 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.

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.

Hsa_circRNA_0001971 contributes to oral squamous cell carcinoma progression via miR-186-5p/Fibronectin type III domain containing 3B axis.

BACKGROUND: Circular RNAs (circRNAs) are closely associated with the progression of oral squamous cell carcinoma (OSCC). circRNA_0001971 has been proved to accelerate the OSCC development. Here, we aim to identify the new molecular mechanism of hsa_circRNA_0001971 (circRNA_0001971) in OSCC. METHODS: The levels of circRNA_0001971, miR-186-5p, and fibronectin type III domain containing 3B (FNDC3B) in tissues and cells were verified by qRT-PCR or Western blotting. The interaction between circRNA_0001971, miR-186-5p, and FNDC3B was identified by bioinformatics analysis, luciferase assay, and RIP assay. The effect of circRNA_0001971/miR-186-5p/FNDC3B axis on OSCC cell proliferation, migration, and invasion by cell functional experiments including CCK8, wound healing, and transwell assays. RESULTS: Our study displayed that circRNA_0001971 and FNDC3B were elevated in OSCC, whereas miR-186-5p was declined in OSCC. Silencing circRNA_0001971 attenuated the malignancy of OSCC cells by suppressing proliferation, migration, and invasion. In OSCC cells, circRNA_0001971 sponged miR-186-5p to enhance FNDC3B. Due to the interaction between circRNA_0001971, miR-186-5p, and FNDC3B, FNDC3B overexpression relieved the negative function of silencing circRNA_0001971 in OSCC cells. CONCLUSION: Overall, our study discovered that circRNA_0001971 was a tumor promoter in OSCC progression by targeting miR-186-5p/FNDC3B axis.

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.

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.

Diagnostic Performance of Circulating miRNAs and Extracellular Vesicles in Acute Ischemic Stroke.

BACKGROUND: Increased inflammation activates blood coagulation system, higher platelet activation plays a key role in the pathophysiology of ischemic stroke (IS). During platelet activation and aggregation process, platelets may cause increased release of several proinflammatory, and prothrombotic mediators, including microRNAs (miRNAs) and extracellular vesicles (EVs). In the current study we aimed to assess circulating miRNAs profile related to platelet function and inflammation and circulating EVs from platelets, leukocytes, and endothelial cells to analyse their diagnostic and predictive utility in patients with acute IS. METHODS: The study population consisted of 28 patients with the diagnosis of the acute IS. The control group consisted of 35 age- and gender-matched patients on acetylsalicylic acid (ASA) therapy without history of stroke and/or TIA with established stable coronary artery disease (CAD) and concomitant cardiovascular risk factors. Venous blood samples were collected from the control group and patients with IS on ASA therapy (a) 24 h after onset of acute IS, (b) 7-days following index hospitalization. Flow cytometry was used to determine the concentration of circulating EVs subtypes (from platelets, leukocytes, and endothelial cells) in platelet-depleted plasma and qRT-PCR was used to determine several circulating plasma miRNAs (miR-19a-3p, miR-186-5p and let-7f). RESULTS: Patients with high platelet reactivity (HPR, based on arachidonic acid-induced platelet aggregometry) had significantly elevated platelet-EVs (CD62+) and leukocyte-EVs (CD45+) concentration compared to patients with normal platelet reactivity at the day of 1 acute-stroke (p = 0.012, p = 0.002, respectively). Diagnostic values of baseline miRNAs and EVs were evaluated with receiver operating characteristic (ROC) curve analysis. The area under the ROC curve for miR-19a-3p was 0.755 (95% CI, 0.63-0.88) p = 0.004, for let-7f, it was 0.874 (95% CI, 0.76-0.99) p = 0.0001; platelet-EVs was 0.776 (95% CI, 0.65-0.90) p = 0.001, whereas for leukocyte-EVs, it was 0.715 (95% CI, 0.57-0.87) p = 0.008. ROC curve showed that pooling the miR-19a-3p expressions, platelet-EVs, and leukocyte-EVs concentration yielded a higher AUC than the value of each individual biomarker as AUC was 0.893 (95% CI, 0.79-0.99). Patients with moderate stroke had significantly elevated miR-19a-3p expression levels compared to patients with minor stroke at the first day of IS. (AUC: 0.867, (95% CI, 0.74-0.10) p = 0.001). CONCLUSION: Combining different biomarkers of processes underlying IS pathophysiology might be beneficial for early diagnosis of ischemic events. Thus, we believe that in the future circulating biomarkers might be used in the prehospital phase of IS. In particular, circulating plasma EVs and non-coding RNAs including miRNAs are interesting candidates as bearers of circulating biomarkers due to their high stability in the blood and making them highly relevant biomarkers for IS diagnostics.

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.

HOXB-AS1 accelerates the tumorigenesis of glioblastoma via modulation of HOBX2 and HOBX3 at transcriptional and posttranscriptional levels.

Glioblastoma (GBM) is the most universal and invasive brain tumor among adults. Increasing studies have reported that long noncoding RNAs play vital roles in regulating downstream molecules at the transcriptional or posttranscriptional level in tumor progression. The purpose of the current research was to inquire the modulation mechanism by which homeobox B cluster antisense RNA 1 (HOXB-AS1) functioned in GBM. Our study first discovered the lifted expression of HOXB-AS1 and its nearby genes HOXB2 and HOXB3 in GBM and the positive relationship between HOXB-AS1 and HOXB2 or HOXB3. Loss-of-function assays and in vivo study detected that silencing of HOXB-AS1, HOXB2, or HOXB3 restrained the proliferation and induced the apoptosis in GBM. In addition, mechanism experiments demonstrated that HOXB-AS1 recruited interleukin enhancer-binding factor 3 (ILF3) to regulate HOXB2 and HOXB3 expression at the transcriptional level, and HOXB-AS1 sponged miR-186-5p to modulate HOXB2 and HOXB3 expression at posttranscriptional level. Finally, the regulatory mechanism of HOXB-AS1 in GBM was certified through rescue experiments. Our results indicated that HOXB-AS1 boost the HOXB2 or HOXB3 expression at the transcriptional and posttranscriptional levels. We detected the HOXB-AS1-ILF3-HOXB2/HOXB3 axis and HOXB-AS1-miR-186-5p-HOXB2/HOXB3 axis driving the GBM progression, which might generate more effective diagnostic biomarkers and therapeutic targets for patients with GBM.

Aerobic exercise improves VCI through circRIMS2/miR-186/BDNF-mediated neuronal apoptosis.

BACKGROUND: Vascular cognitive impairment (VCI) is a common cognitive disorder caused by cerebrovascular disease, ranging from mild cognitive impairment to dementia. Studies have shown that aerobic exercise might alleviate the pathological development of VCI, and our previous study observed that aerobic exercise could alleviate VCI through NF-κB/miR-503/BDNF pathway. However, there are few studies on the mechanism. Therefore, it is of great significance to fill the gaps in the mechanism for the early diagnosis of VCI and the clinical prevention and treatment of vascular dementia. METHODS: CircRNA microarray analysis and quantitative real-time PCR were used to detect the expression of circRNA regulating synaptic be exocytosis 2 (RIMS2) (circRIMS2). Cell apoptosis was determined by TdT-mediated dUTP nick-end labeling (TUNEL) assay. The dual-luciferase reporter assay was performed to verify the interaction between circRIMS2 and miR-186, as well as miR-186 and BDNF. RNA pull-down assay detected the binding between circRIMS2 and miR-186. A VCI mouse model was established by repeated ligation of bilateral common carotid arteries (2VO). The lentiviral interfering vector was injected into the VCI mice through the lateral ventricle. The mice in the aerobic exercise group performed 30 min (12 m/min) running for 5 days a week. A Morris water maze test was performed after 4 weeks. RESULTS: The expression of circRIMS2 and BDNF in the serum of VCI patients was significantly reduced, miR-186 expression was increased, and the expression of circRIMS2 was increased in the 2VO group of mice undergoing aerobic exercise. The expression levels of circRIMS2 and BDNF in the oxygen and glucose deprivation-treated (OGD-treated) cells were decreased, the miR-186 expression and cell apoptosis were increased, while the effect was weakened after transfection with the lentiviral vector pLO-ciR-RIMS2. CircRIMS2 could bind to miR-186, and after interference with circRIMS2 in HT22 cells, the expression of miR-186 was increased. Besides, miR-186 could bind to BDNF, and BDNF expression was decreased because of the overexpression of miR-186 in HT22 cells. The expression level of BDNF in the pLO-ciR-RIMS2 group was increased, and apoptosis was decreased, but the miR-186 mimic weakened the effect of pLO-ciR-RIMS2. Aerobic exercise could shorten the average time that mice reached the platform in the Morris water maze, increase the expression level of circRIMS2 and BDNF, reduce miR-186 expression, and inhibit neuronal apoptosis. However, the interference with circRIMS2 weakened this effect. CONCLUSION: The expression of circRIMS2 was down-regulated in VCI and aerobic exercise reduced neuronal apoptosis, and circRIMS2 improved VCI through the circRIMS2/miR-186/BDNF axis.

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

TGFß 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 TGFß 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.

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.

Hsa_circ_0004058 inhibits apoptosis of SRA01/04 cells by promoting autophagy via miR-186/ATG7 axis.

Senile cataract is a common age-related disease in ophthalmology. Hsa_circ_0004058 has been reported to be down-regulated in the lens epithelial cells of senile cataract patients, suggesting that hsa_circ_0004058 is associated with senile cataract. However, the underlying mechanism is still unknown. This study attempted to determine the functional role of hsa_circ_0004058 in senile cataract. We treated human lens epithelial cells (SRA01/04) with H2O2 as senile cataract model, and found that cell viability and autophagy of SRA01/04 cells were severely decreased by H2O2 treatment. Hsa_circ_0004058 was notably down-regulated in H2O2-treated SRA01/04 cells. Moreover, hsa_circ_0004058 overexpression reduced apoptotic cells and the expression of Cleaved-caspase-3 and Bax, and enhanced Bcl-2 expression in H2O2-treated SRA01/04 cells. However, hsa_circ_0004058 silencing caused the opposite results. Hsa_circ_0004058 up-regulation accelerated the expression of autophagy-related proteins LC3-II/LC3-I and Beclin-1 in H2O2-treated SRA01/04 cells, which was partly abolished by 3-Methyladenine (autophagy inhibitor). Additionally, hsa_circ_0004058 functioned as a competing endogenous RNA to competitive binding miR-186, and thus accelerated the expression of its down-stream target, ATG7. Hsa_circ_0004058 promoted autophagy of SRA01/04 cells by regulating miR-186/ATG7 axis. In conclusion, these data demonstrates that hsa_circ_0004058 inhibits apoptosis of SRA01/04 cells by promoting autophagy, which attributes to regulate miR-186/ATG7 axis. Thus, hsa_circ_0004058 may be a potential target for senile cataract treatment.

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.