MicroRNAs: something important between the genes

Dynamic Nanostructure-Based DNA Logic Gates for Cancer Diagnosis and Therapy

DNA logic gates with dynamic nanostructures have made a profound impact on cancer diagnosis and treatment. Through programming the dynamic structure changes of DNA nanodevices, precise molecular recognition with signal amplification and smart therapeutic strategies have been reported. This enhances the specificity and sensitivity of cancer theranostics, and improves diagnosis precision and treatment outcomes. This review explores the basic components of dynamic DNA nanostructures and corresponding DNA logic gates, as well as their applications for cancer diagnosis and therapies. The dynamic DNA nanostructures would contribute to cancer early detection and personalized treatment.

Discovering genes and microRNAs involved in human lung development unveils IGFBP3/miR-34a dynamics and their relevance for alveolar differentiation

BACKGROUND

During pseudoglandular stage of the human lung development the primitive bronchial buds are initially conformed by simple tubules lined by endoderm-derived epithelium surrounded by mesenchyme, which will progressively branch into airways and start to form distal epithelial saculles. For first time alveolar type II (AT2) pneumocytes appears. This study aims to characterize the genes and microRNAs involved in this differentiation process and decipher its role in the starting alveolar differentiation.

METHODS

Gene and microRNA profiling was performed in human embryonic lungs from 7 to 12 post conception weeks (pcw). Protein expression location of candidate genes were analyzed by immunofluorescense in embryonic lung tissue sections. mRNA/miRNA target pairs were identified using computational approaches and their expression was studied in purified epithelial/mesenchymal cell populations and in isolated tips and stalks from the bronchial tree. Additionally, silencing experiments in human embryonic lung mesenchymal cells and in human embryonic tip-derived lung organoids were performed, as well as organoid differentiation studies. AT2 cell markers were studied by qRT-PCR and by immunofluorescence. The TGFB-β phosphorylated pathways was analyzed with membrane protein arrays. Lung explants were cultured in air/liquid interface with/without peptides.

RESULTS

We identified 88 differentially expressed genes, including IGFBP3. Although IGFBP3 mRNA was detected in both epithelial and mesenchymal populations, the protein was restricted to the epithelium, indicating post-transcriptional regulation preventing IGFBP3 protein expression in the mesenchyme. MicroRNA profiling identified miR-34a as an IGFBP3 regulator. miR-34a was up-regulated in mesenchymal cells, and its silencing in human embryonic lung mesenchymal cells increased IGFBP3 levels. Additionally, IGFBP3 expression showed a marked downregulation from 7 to 12 pcw, suggesting its involvement in the differentiation process. The differentiation of human tip-derived lung embryonic organoids showed a drastic reduction in IGFBP3, supported by the scRNAseq data. IGFBP3 silencing in organoids activated an alveolar-like differentiation process characterized by stem cell markers downregulation and upregulation of AT2 markers. This process was mediated by TGFβ signalling inhibition and BMP pathway activation.

CONCLUSIONS

The IGFBP3/miR-34a axis restricts IGFBP3 expression in the embryonic undifferentiated lung epithelium, and the progressive downregulation of IGFBP3 during the pseudoglandular stage is required for alveolar differentiation.

Ginsenoside Re inhibits myocardial fibrosis by regulating miR-489/myd88/NF-κB pathway

Background

Myocardial fibrosis (MF) is an advanced pathological manifestation of many cardiovascular diseases, which can induce heart failure and malignant arrhythmias. However, the current treatment of MF lacks specific drugs. Ginsenoside Re has anti-MF effect in rat, but its mechanism is still not clear. Therefore, we investigated the anti-MF effect of ginsenoside Re by constructing mouse acute myocardial infarction (AMI) model and AngⅡ induced cardiac fibroblasts (CFs) model.

Methods

The anti-MF effect of miR-489 was investigated by transfection of miR-489 mimic and inhibitor in CFs. Effect of ginsenoside Re on MF and its related mechanisms were investigated by ultrasonographic, ELISA, histopathologic staining, transwell test, immunofluorescence, Western blot and qPCR in the mouse model of AMI and the AngⅡ-induced CFs model.

Results

MiR-489 decreased the expression of α-SMA, collagenⅠ, collagen Ⅲ and myd88, and inhibited the phosphorylation of NF-κB p65 in normal CFs and CFs treated with AngⅡ. Ginsenoside Re could improve cardiac function, inhibit collagen deposition and CFs migration, promote the transcription of miR-489, and reduce the expression of myd88 and the phosphorylation of NF-κB p65.

Conclusion

MiR-489 can effectively inhibit the pathological process of MF, and the mechanism is at least partly related to the regulation of myd88/NF-κB pathway. Ginsenoside Re can ameliorate AMI and AngⅡ induced MF, and the mechanism is at least partially related to the regulation of miR-489/myd88/NF-κB signaling pathway. Therefore, miR-489 may be a potential target of anti-MF and ginsenoside Re may be an effective drug for the treatment of MF.

Role of lncRNA-MEG8/miR-296-3p axis in gestational diabetes mellitus

AIM

Gestational diabetes mellitus (GDM) is the most common complication in pregnancy. This study aimed to investigate the potential mechanism and effects of long-noncoding RNA maternally expressed 8 (lncRNA-MEG8) in GDM.

METHODS

Targeted interactions involving lncRNA-MEG8 and miR-296-3p were initially predicted using starBase software and then confirmed using dual-luciferase reporter gene analysis. The expression levels of lncRNA-MEG8 and miR-296-3p in peripheral blood samples from patients with GDM were measured using reverse transcription-quantitative polymerase chain reaction. Enzyme-linked immunosorbent assay was used to evaluate the overall levels of insulin and insulin secretion. Additionally, MTT and flow cytometric methods were used to detect cell viability and apoptosis. Cell apoptosis-associated proteins were determined by western blotting.

RESULTS

Our results indicated that lncRNA-MEG8 is a potential target of miR-296-3p. lncRNA-MEG8 level was higher, whereas that of miR-296-3p was lower in patients with GDM than in healthy individuals. LncRNA-MEG8-siRNA promoted insulin content and secretion. Furthermore, MEG8-siRNA increased cell viability and decreased apoptosis. However, these changes were reversed by an miR-296-3p inhibitor. Moreover, a miR-296-3p mimic had the same effect on INS-1 cells as MEG8-siRNA, as evidenced by enhanced insulin secretion, cell viability, and reduced apoptosis.

CONCLUSION

LncRNA-MEG8-siRNA promotes pancreatic β-cell function by upregulating miR-296-3p.

miR-18a-5p Reduces Inflammatory Response and Human Dermal Microvascular Endothelial Cells Permeability by Targeting Thrombospondin 1 in Chronic Idiopathic Urticaria

Chronic idiopathic urticaria (CIU) is a skin disease that has an acute attack when patient encounters an allergen. Previous research demonstrated that microRNA (miRNA) has a crucial role in CIU occurrence and development. This study aimed to investigate the role and mechanism of miR-18a-5p in CIU. StarBase and dual luciferase reporter gene assay confirmed that thrombospondin 1 (THBS1) was a direct target of miR-18a-5p. miR-18a-5p negatively regulated THBS1 expression in human mast cell line HMC-1 and human dermal microvascular endothelial cells (HDMECs). Further analysis indicated that miR-18a-5p mimic significantly reduced inflammatory factors including interleukin (IL)-6, IL-8, IL-1β and tumor necrosis factor (TNF)-α release, decreased the degranulation rate and histamine release rate of HMC-1 cells. Besides, we found that miR-18a-5p reduced the permeability of HDMECs by suppressing THBS1 expression. Finally, the data indicated that miR-18a-5p inhibited the transforming growth factor beta (TGF-β)/SMAD family member 3 (Smad3) signaling pathway in HDMECs by inhibiting the expression of THBS1. Taken together, the results suggested that miR-18a-5p reduced inflammation and human skin microvascular endothelial cell permeability in CIU by targeting THBS1. miR-18a-5p might be a new target for CIU treatment.

Significant role of long non-coding RNA MALAT1 in deep vein thrombosis via the regulation of vascular endothelial cell physiology through the microRNA-383-5p/BCL2L11 axis

Deep vein thrombosis (DVT) is a vascular disease. The long non-coding RNA (lncRNA), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), is positively expressed in DVT tissues, and regulates the biological behavior of endothelial progenitor cells. Here, we explored whether MALAT1 affected the physiology of human vascular endothelial cells (HUVECs) and analyzed its underlying mechanism. To overexpress/silence the expression of MALAT1 in HUVECs, MALAT1-plasmid/MALAT1-small interfering RNA (siRNA) was used. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and flow cytometry analyses were performed to observe the cell viability and apoptosis. Reverse transcription-quantitative polymerase chain reaction and western blotting were used to determine the apoptosis-related protein and gene expression levels. We used Starbase software to predict the associations among MALAT1, microRNA (miR)-383-5p, and BCL2-like 11 (BCL2L11). Luciferase reporter assay was used to validate their relationship. Compared to the control vector group, MALAT1-plasmid suppressed the viability and induced apoptosis of HUVECs, while improving Bcl-2-associated X protein (Bax) expression and decreasing Bcl-2 expression. There was an interaction between MALAT1 and miR-383-5p. Compared to the control siRNA group, MALAT1-siRNA increased the cell viability, reduced cell apoptosis, upregulated Bcl-2 expression, and suppressed Bax expression. These changes were reversed by the miR-383-5p inhibitor. Additionally, we verified that BCL2L11 is a target of miR-383-5p. miR-383-5p improved the cell proliferation, while decreasing cell apoptosis in HUVECs by targeting BCL2L11. Therefore, the lncRNA-MALAT1/miR-383-5p/BCL2L11 axis may be effective for DVT treatment.

DNA Logic Circuits for Cancer Theranostics

Cancer diagnosis and therapeutics (theranostics) based on the tumor microenvironment (TME) and biomarkers has been an emerging approach for precision medicine. DNA nanotechnology dynamically controls the self-assembly of DNA molecules at the nanometer scale to construct intelligent DNA chemical reaction systems. The DNA logic circuit is a particularly emerging approach for computing within the DNA chemical systems. DNA logic circuits can sensitively respond to tumor-specific markers and the TME through logic operations and signal amplification, to generate detectable signals or to release anti-cancer agents. In this review, the fundamental concepts of DNA logic circuits are clarified, the basic modules in the circuit are summarized, and how this advanced nano-assembly circuit responds to tumor-related molecules, how to perform logic operations, to realize signal amplification, and selectively release drugs through discussing over 30 application examples, are demonstrated. This review shows that DNA logic circuits have powerful logic judgment and signal amplification functions in improving the specificity and sensitivity of cancer diagnosis and making cancer treatment controllable. In the future, researchers are expected to overcome the existing shortcomings of DNA logic circuits and design smarter DNA devices with better biocompatibility and stability, which will further promote the development of cancer theranostics.

MicroRNA-30a contributes to pre-eclampsia through regulating the proliferation, apoptosis, and angiogenesis modulation potential of mesenchymal stem cells by targeting AVEN

Pre-eclampsia (PE) is a pregnancy-associated disease related to an unprecedented hypertension attack. Mesenchymal stem cells (MSCs) play a crucial role in PE pathology. . Our research was designed to illustrate the functions of microRNA-30a (miR-30a) in proliferation, apoptosis, and the potential of regulating angiogenesis in MSCs, and to analyze its potential molecular mechanisms. TargetScan software and the luciferase reporter assay were used to forecast and verify the relationship between miR-30a and AVEN. MiR-30a and AVEN expression in the decidual tissue and decidua (d)MSCs of healthy pregnant women and PE patients were assessed using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Cell proliferation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2 H-tetrazolium bromide (MTT), flow cytometry, and transwell assays were used to evaluate cell proliferation, growth, the cell cycle, apoptosis, and migration. Furthermore, the tube formation ability was evaluated using the human umbilical vein endothelial cell (HUVEC) tube formation assay. AVEN is the target gene of miR-30a. MiR-30a was upregulated in decidual tissues and dMSCs of PE patients. However, AVEN was weakly expressed, and AVEN expression was negatively related to miR-30a levels in decidual tissues and dMSCs of PE patients. Compared to the mimic control group, upregulation of miR-30a inhibited dMSC proliferation and cell growth, promoted G0/G1 phase arrest, and induced apoptosis. Furthermore, the miR-30a mimic transfected dMSC culture supernatant suppressed HTR-8/SVneo cell migration ability and HUVEC tube formation ability. However, AVEN reversed these changes. In conclusion, miR-30a/AVEN may serve as a new axis for PE treatment.

Rice microRNA171f/SCL6 module enhances drought tolerance by regulation of flavonoid biosynthesis genes

Plants have evolved sophisticated defense systems to enhance drought tolerance. These include the microRNA (miRNA) group of small noncoding RNAs that act as post-transcriptional regulators; however, details of the mechanisms by which they confer drought tolerance are not well understood. Here, we show that osa-MIR171f, a member of osa-MIR171 gene family, is mainly expressed in response to drought stress and regulates the transcript levels of SCARECROW-LIKE6-I (SCL6-I) and SCL6-II in rice (Oryza sativa). The SCL6 genes are known to be involved in shoot branching and flag leaf morphology. Osa-MIR171f-overexpressing (osa-MIR171f-OE) transgenic plants showed reduced drought symptoms compared with non-transgenic (NT) control plants under both field drought and polyethylene glycol (PEG)-mediated dehydration stress conditions. Transcriptome analysis of osa-MIR171f-OE plants and osa-mir171f-knockout (K/O) lines generated by clustered regularly interspaced short palindromic repeats (CRISPR/Cas9) revealed that osa-mature-miR171a-f (osa-miR171) regulates the expression of flavonoid biosynthesis genes, consequently leading to drought tolerance. This upregulation in the osa-MIR171f-OE plants, which did not occur in NT control plants, was observed under both normal and drought conditions. Our findings indicate that osa-miR171 plays a role in drought tolerance by regulating SCL6-I and SCL6-II transcript levels.

MicroRNA-300 Inhibits the Proliferation and Metastasis of Cervical Cancer Cells via Posttranscriptional Suppression of G Protein-Coupled Receptor 34 (GPR34)

Cervical cancer is one of the dominant gynecological disorders which has poor prognosis and often diagnosed at advanced stages where it becomes nearly impossible to effectively manage this disorder. MicroRNA-300 (miR-300) has dual role in human tumorogenesis. However, characterization of its regulatory action has not been made in cervical cancer. The molecular role of miR-300 in cervical cancer was thus explored in the present study with prime focus on elucidating its mechanism of action. The results showed significant (P < 0.05) downregulation of miR-300 in cervical cancer. Overexpression of miR-300 in cervical cancer cells inhibited their proliferation in vitro by inducing apoptosis. Cervical cancer cells overexpressing miR-300 also showed decreased rates of migration and invasion. G protein-coupled receptor 34 (GPR34) was found to be the functional regulatory target of miR-300 in cervical cancer. GPR34 was found to be significantly (P < 0.05) overexpressed in cervical cancer tissues and cell lines. Silencing of GPR34 inhibited the growth of the cervical cancer cells. However, overexpression of GPR34 could prevent the tumor-suppressive effects of miR-300 on cervical cancer cells. Collectively, the results of the current study are indicative of the tumor-suppressive regulatory role of miR-300 in cervical cancer and suggestive of the potential therapeutic value of miR-300/GPR34 molecular axis.

Ox-LDL Aggravates the Oxidative Stress and Inflammatory Responses of THP-1 Macrophages by Reducing the Inhibition Effect of miR-491-5p on MMP-9

Background: Oxidized low-density lipoprotein (ox-LDL) can induce oxidative stress and inflammatory responses in macrophages to facilitate the genesis and development of atherosclerosis. However, the intermediate links remain unclear. MiR-491-5P can inhibit matrix metalloproteinase 9 (MMP-9); however, it remains unclear whether ox-LDL enhances MMP-9 expression and aggravates the oxidative stress and inflammatory responses under the mediating effect of miR-491-5P.

Method: THP-1 macrophages were divided into 10 groups: blank (control), model (ox-LDL), miR-491-5P high-expression (miR-491-5P mimic), miR-491-5P control (mimic-NC), MMP-9 high-expression (MMP-9-plasmid), MMP-9 control (plasmid-NC), miR-491-5P+plasmid-NC, miR-491-5P+ MMP-9-plasmid, MMP-9 gene silencing (MMP-9-siRNA), and gene silencing control (siRNA-NC). The cells were transfected for 48 h and then treated with 50 μg/mL of ox-LDL for 24 h. MMP-9 mRNA and miR-491-5P expression levels in the cells were detected using reverse transcription-quantitative polymerase chain reaction, and the MMP-9 levels were detected with western blotting. The levels of oxidative stress factors (malondialdehyde [MDA]), reactive oxygen species (ROS), and antioxidant factors (superoxide dismutase [SOD]), and the expression levels of inflammatory factors (tumor necrosis factor [TNF-α] and interleukin-1β and−6 [IL-1β and IL-6]) in the supernatant were detected with enzyme-linked immunosorbent assay.

Results: MDA, ROS, TNF-α, IL-1β, IL-6, and MMP-9 levels were increased, SOD activity was reduced, and miR-491-5P expression was downregulated in the ox-LDL group compared to the control group. In the miR-491-5P mimic group, the MDA, ROS, TNF-α, IL-1β, IL-6, MMP-9 mRNA and protein levels were downregulated, and SOD activity was enhanced compared to the ox-LDL group. MMP-9-plasmid elevated the MDA, ROS, TNF-α, IL-1β, IL-6, MMP-9 mRNA and protein levels, and downregulated SOD activity and miR-491-5P expression. Following transfection with MMP-9-siRNA, the MMP-9-plasmid outcomes were nullified, and the resulting trends were similar to the miR-491-5p simulation group. Oxidative stress and inflammatory responses were higher in the miR-491-5P mimic+MMP-9-plasmid co-transfection group than in the miR-491-5P mimic group.

Conclusion: Ox-LDL aggravates the oxidative stress and inflammatory responses of THP-1 macrophages by reducing the inhibition effect of miR-491-5p on MMP-9.

miR-489-3p overexpression inhibits lipopolysaccharide-induced nucleus pulposus cell apoptosis, inflammation and extracellular matrix degradation via targeting Toll-like receptor 4

Intervertebral disc degeneration (IDD) is a common disease with a high morbidity rate, which results in a significant deterioration in the quality of life of patients. MicroRNAs (miRNAs/miRs) are a class of endogenous small non-coding RNAs that influence target genes and serve critical roles in numerous biological processes. However, the role of miR-489-3p in lumbar disc degeneration is yet to be elucidated. In the present study, human NP cells were treated with 10 ng/ml lipopolysaccharide (LPS) for 24 h to investigate the role of miR-489-3p in IDD in an in vitro model. Reverse transcription-quantitative (RT-q)PCR was performed to determine the expression levels of miR-489-3p. Then, the TargetScan database was used to predict the potential binding sites between miR-489-3p and Toll-like receptor (TLR)4, and a dual-luciferase reporter assay was performed to verify the findings. Subsequently, RT-qPCR and western blotting were used to analyze the expression levels of TLR4. In addition, human nucleus pulposus (NP) cells were transfected with a miR-489-3p mimic and TLR4 overexpression plasmid to study the effects of miR-489-3p on LPS-induced human NP cells. Cell apoptosis and cell viability were also determined using flow cytometry and MTT assays, respectively. Finally, ELISAs were performed to analyze the levels of inflammatory factors. The expression levels of miR-489-3p were discovered to be downregulated in LPS-treated human NP cells. In addition, TLR4 was revealed to be a direct target gene of miR-489-3p, and its expression levels were upregulated in LPS-treated human NP cells. miR-489-3p was found to inhibit the LPS-induced decreases in cell viability and increases in apoptosis, and the concentration of inflammatory cytokines. Furthermore, miR-489-3p suppressed the LPS-induced decreases in extracellular matrix deposition via decreasing the expression levels of aggrecan and collagen type II in human NP cells. Finally, the results revealed that miR-489-3p inhibited the LPS-induced activation of the NF-κB signaling pathway in human NP cells. Conversely, all of the effects of miR-489-3p on LPS-induced human NP cells were reversed by the TLR4 overexpression plasmid. These findings suggested that miR-489-3p may represent a novel therapeutic target for the treatment of IDD.

miR-122-5p downregulation attenuates lipopolysaccharide-induced acute lung injury by targeting IL1RN

MicroRNAs (miRs) and inflammatory cytokines can induce acute lung injury (ALI), which can develop into acute respiratory distress syndrome in severe cases. Previous research has revealed that miR-122-5p participates in the development of ALI, and that its expression is positively associated with ALI. However, the mechanism by which miR-122-5p contributes to ALI remains to be determined. In the current study, TargetScan and dual luciferase reporter gene assays were used to confirm that IL-1 receptor antagonist (IL1RN) was a target of miR-122-5p. Subsequently, by referring to previous literature, a lipopolysaccharide (LPS)-induced ALI cell model was established. A549 cells were transfected with mimic control or miR-122-5p mimics for 24 h, and 10 µg LPS was used to treat the transfected cells for 12 h. The results revealed that miR-122-5p mimics decreased cell viability and promoted apoptosis. Lactate dehydrogenase (LDH) release assays indicated that miR-122-5p mimics increased LDH release. ELISA demonstrated that miR-122-5p mimics promoted TNF-α, IL-1β and IL-6 expression levels. A549 cells were transfected with inhibitor control, miR-122-5p inhibitor, miR-122-5p inhibitor + control-small interfering (si)RNA or miR-122-5p inhibitor + IL1RN-siRNA for 24 h, after which the cells were treated with 10 µg LPS for 12 h. The results revealed that the effects of the miR-122-5p inhibitor were the opposite of those of the miR-122-5p mimic. All the effects of miR-122-5p inhibitor on LPS-treated A549 cells were significantly reversed by IL1RN-siRNA. Overall, the results highlighted miR-122-5p as a potential novel target for the treatment of ALI.

MicroRNA-20a-5p suppresses tumor angiogenesis of non-small cell lung cancer through RRM2-mediated PI3K/Akt signaling pathway

The current therapeutic strategies for non-small cell lung cancer (NSCLC) are limited and unsatisfactory. MicroRNAs (miRNAs) participate in tumor angiogenesis in NSCLC. The aim of this study was to investigate the role of miR-20a-5p (miR-20a) in human NSCLC metastasis. In the current study, bioinformatics analysis and RT-PCR were performed to examine the expression level of miR-20a in tissues of NSCLC patients and NSCLC cell lines, respectively. Western blot was performed to test the protein levels. Cell proliferation, migration and angiogenesis capacity were tested by 5-ethynyl-29-deoxyuridine (EdU) assay, transwell assay and tube formation assay, respectively. Dual-luciferase reporter assay (DLR) was used to confirm the interaction between miR-20a and paired ribonucleotide reductase regulatory subunit M2 (RRM2). We found that the expression of RRM2 was upregulated, while the expression of miR-20a was downregulated in cancer tissues compared with adjacent tissues in NSCLC patients. We also detected the expression level of RRM2 and miR-20a in NSCLC cell lines, showing A549 cell line exhibited the lowest expression level of miR-20a and highest expression level of RRM2. Overexpressed miR-20a not only dramatically suppressed NSCLC cells proliferation, endothelial cells migration and tube formation in vitro, but also inhibited tumor growth and angiogenesis in vivo. It was demonstrated that miR-20a suppressed NSCLC growth by inhibiting RRM2-mediated PI3K/Akt signaling pathway. These findings indicate that the novel identified miR-20a could function as a tumor suppressor in NSCLC through modulating the RRM2-mediated PI3K/Akt axis, and it could be a valid molecular target for NSCLC treatment.

MicroRNA-182-5p relieves murine allergic rhinitis via TLR4/NF-κB pathway

Allergic rhinitis (AR) is one of the most common chronic diseases. This study examined whether microRNA (miR)-182-5p plays a role in AR by regulating toll-like receptor 4 (TLR4). First, data demonstrated that TLR4 was a target of miR-182-5p. Subsequently, AR mouse model was established to explore the role of miR-182-5p and TLR4 in AR in vivo. Initially, quantitative reverse transcription-PCR (qRT-PCR) analysis indicated that miR-182-5p was downregulated, while TLR4 expression was upregulated in AR mice. Then we found that miR-182-5p mimic reduced the frequency of sneezing and nose rubbing of the AR mice. In addition, miR-182-5p mimic significantly increased ovalbumin (OVA)-specific IgE and leukotriene C4 expression levels in nasal lavage fluid (NLF) and serum of AR mice. miR-182-5p mimic decreased the number of inflammatory cells in NLF of AR mice. It also reduced the levels of inflammatory factors in the serum of AR mice, such as interleukin (IL)-4, IL-5, IL-13, IL-17 and tumor necrosis factor (TNF)-α, while increasing the release of IFN-γ and IL-2. Finally, miR-182-5p mimic inhibited NF-κB signaling pathway activation in AR mice. However, all effects of miR-182-5p mimic on AR mice were reversed by TLR4-plasmid. In conclusion, miR-182-5p/TLR4 axis may represent a novel therapeutic target for AR.

Therapeutically Significant MicroRNAs in Primary and Metastatic Brain Malignancies

Simple Summary

The overall survival of brain cancer patients remains grim, with conventional therapies such as chemotherapy and radiotherapy only providing marginal benefits to patient survival. Cancers are complex, with multiple pathways being dysregulated simultaneously. Non-coding RNAs such as microRNA (miRNAs) are gaining importance due to their potential in regulating a variety of targets implicated in the pathology of cancers. This could be leveraged for the development of targeted and personalized therapies for cancers. Since miRNAs can upregulate and/or downregulate proteins, this review aims to understand the role of these miRNAs in primary and metastatic brain cancers. Here, we discuss the regulatory mechanisms of ten miRNAs that are highly dysregulated in glioblastoma and metastatic brain tumors. This will enable researchers to develop miRNA-based targeted cancer therapies and identify potential prognostic biomarkers.

Abstract

Brain cancer is one among the rare cancers with high mortality rate that affects both children and adults. The most aggressive form of primary brain tumor is glioblastoma. Secondary brain tumors most commonly metastasize from primary cancers of lung, breast, or melanoma. The five-year survival of primary and secondary brain tumors is 34% and 2.4%, respectively. Owing to poor prognosis, tumor heterogeneity, increased tumor relapse, and resistance to therapies, brain cancers have high mortality and poor survival rates compared to other cancers. Early diagnosis, effective targeted treatments, and improved prognosis have the potential to increase the survival rate of patients with primary and secondary brain malignancies. MicroRNAs (miRNAs) are short noncoding RNAs of approximately 18–22 nucleotides that play a significant role in the regulation of multiple genes. With growing interest in the development of miRNA-based therapeutics, it is crucial to understand the differential role of these miRNAs in the given cancer scenario. This review focuses on the differential expression of ten miRNAs (miR-145, miR-31, miR-451, miR-19a, miR-143, miR-125b, miR-328, miR-210, miR-146a, and miR-126) in glioblastoma and brain metastasis. These miRNAs are highly dysregulated in both primary and metastatic brain tumors, which necessitates a better understanding of their role in these cancers. In the context of the tumor microenvironment and the expression of different genes, these miRNAs possess both oncogenic and/or tumor-suppressive roles within the same cancer.

MicroRNA‑25‑3p regulates human nucleus pulposus cell proliferation and apoptosis in intervertebral disc degeneration by targeting Bim

Intervertebral disc degeneration (IDD) is a degenerative disease of the spine originating from the intervertebral disc. MicroRNAs (miRNAs or miRs) are a group of endogenous small non‑coding RNAs that act on target genes and play a critical role in numerous biological processes. However, the underlying mechanism of miR‑25‑3p in IDD remains unclear. Therefore, the present study aimed to explore the role of miR‑25‑3p in the pathogenesis of IDD. The results demonstrated that miR‑25‑3p was downregulated in rat degenerative nucleus pulposus (NP) cells and that Bcl‑2 interacting mediator of cell death (Bim) was a direct target of miR‑25‑3p. Next, to investigate the effect of miR‑25‑3p on normal NP cell proliferation and apoptosis, NP cells were transfected with an miR‑25‑3p inhibitor, a negative control of miR‑25‑3p inhibitor, miR‑25‑3p inhibitor + control‑small interference RNA (siRNA) or miR‑25‑3p inhibitor + Bim‑siRNA for 48 h and cell proliferation and apoptosis were then analyzed. The results demonstrated that the miR‑25‑3p inhibitor could decrease NP cell proliferation and induce cell apoptosis, and these effects were reversed by Bim‑siRNA. In addition, an in vitro cell model of IDD was established by subjecting NP cells to 10 ng/ml interleukin (IL)‑1β for 24 h. Further experiments suggested that IL‑1β treatment induced a reduction in NP cell proliferation and an increase in cell apoptosis, which were prevented by the miR‑25‑3p mimic. All the effects of miR‑25‑3p mimic on IL‑1β‑treated NP cells were significantly reversed by Bim upregulation. These findings suggested that miR‑25‑3p may be a novel therapeutic target for IDD prevention.

Impact of potassium deficiency on cotton growth, development and potential microRNA-mediated mechanism

The goal of this study was to investigate the impact of potassium deficiency on cotton seedling growth and development at the individual, physiological, biochemical, and molecular levels. Potassium is an important plant nutrient; our results show that potassium deficiency significantly affected cotton seedling growth and development, evidenced by reduced plant height, and total areas of the leaves and roots as well as further reduced both fresh and dry biomass of the entire plants. Potassium deficiency also significantly inhibited root and leaf respiration and leaf photosynthesis. Compared with the controls, potassium deficiency significantly inhibited root elongation and total root surface areas that further inhibited cotton seedlings to uptake nutrients from the medium. Potassium deficiency induced aberrant expression of both microRNAs (miRNAs) and their protein-coding targets. These miRNAs regulate plant root development as well as response to abiotic stresses. Potassium deficiency altered the expression of miRNAs that regulate the expression of protein-coding genes controlling root development and response to potassium deficiency. miRNAs regulate root development and further control plant development in cotton seedlings under potassium deficiency. In summary, potassium deficiency significantly affected the cotton seedling photosynthesis and respiration that resulted in inhibition of cotton seedling growth and development potentially due to the miRNA-mediated mechanism.

Identification of the differential expression of genes and upstream microRNAs in small cell lung cancer compared with normal lung based on bioinformatics analysis

Small cell lung cancer (SCLC) is one of the most lethal cancer, mainly attributing to its high tendency to metastasis. Mounting evidence has demonstrated that genes and microRNAs (miRNAs) are related to human cancer onset and progression including invasion and metastasis.An eligible gene dataset and an eligible miRNA dataset were downloaded from the Gene Expression Omnibus (GEO) database based our screening criteria. Differentially expressed genes (DE-genes) or DE-miRNAs for each dataset obtained by the R software package. The potential target genes of the top 10 DE-miRNAs were predicted by multiple databases. For annotation, visualization and integrated discovery, Metascape 3.0 was introduced to perform enrichment analysis for the DE-genes and the predicted target genes of the selected top 10 DE-miRNAs, including Pathway and Process Enrichment Analysis or protein-protein interaction enrichment analysis. The intersection of predicted target genes and DE-genes was taken as the final DE-genes. Then apply the predicted miRNAs-targets relationship of top 10 DE-miRNAs to the final DE-genes to gain more convinced DE-miRNAs, DE-genes and their one to one relationship.GSE19945 (miRNA microarray) and GSE40275 (gene microarray) datasets were selected and downloaded. 56 DE-miRNAs and 861 DE-genes were discovered. 297 miRNAs-targets relationships (284 unique genes) were predicted as the target of top 10 upregulating DE-miRNAs. 245 miRNAs-targets relationships (238 unique genes) were identified as the target of top 10 downregulating DE-miRNAs. The key results of enrichment analysis include protein kinase B signaling, transmembrane receptor protein tyrosine kinase signaling pathway, negative regulation of cell differentiation, response to growth factor, cellular response to lipid, muscle structure development, response to growth factor, signaling by Receptor Tyrosine Kinases, epithelial cell migration, cellular response to organic cyclic compound, Cell Cycle (Mitotic), DNA conformation change, cell division, DNA replication, cell cycle phase transition, blood vessel development, inflammatory response, Staphylococcus aureus infection, leukocyte migration, and myeloid leukocyte activation. Differential expression of genes-upstream miRNAs (RBMS3-hsa-miR-7-5p, NEDD9-hsa-miR-18a-5p, CRIM1-hsa-miR-18a-5p, TGFBR2-hsa-miR-9-5p, MYO1C-hsa-miR-9-5p, KLF4-hsa-miR-7-5p, EMP2-hsa-miR-1290, TMEM2-hsa-miR-18a-5p, CTGF-hsa-miR-18a-5p, TNFAIP3-hsa-miR-18a-5p, THBS1-hsa-miR-182-5p, KPNA2-hsa-miR-144-3p, GPR137C-hsa-miR-1-3p, GRIK3-hsa-miR-144-3p, and MTHFD2-hsa-miR-30a-3p) were identified in SCLC.RBMS3, NEDD9, CRIM1, KPNA2, GPR137C, GRIK3, hsa-miR-7-5p, hsa-miR-18a-5p, hsa-miR-144-3p, hsa-miR-1-3p along with the pathways included protein kinase B signaling, muscle structure development, Cell Cycle (Mitotic) and blood vessel development may gain a high chance to play a key role in the prognosis of SCLC, but more studies should be conducted to reveal it more clearly.

Downregulation of microRNA-3934-5p induces apoptosis and inhibits the proliferation of neuroblastoma cells by targeting TP53INP1

Neuroblastoma is the most common pediatric extracranial solid tumour in the world. miRNAs are a group of endogenous small non-coding RNAs that act on target genes to serve critical roles in many biological processes. Presently, the expression and role of miR-3934-5p in neuroblastoma remains unclear. Therefore, the aim of the present study was to investigate the expression of miR-3934-5p in neuroblastoma tissues and cell lines and to assess the role of miR-3934-5p in neuroblastoma. In the current study, the results revealed that miR-3934-5p was significantly upregulated in neuroblastoma tissues and cell lines. The data also identified TP53INP1 as a direct target gene of miR-3934-5p, which was negatively regulated by miR-3934-5p. The present study further demonstrated that TP53INP1 was downregulated in both neuroblastoma tissues and cell lines. Furthermore, the results of the current study indicate that miR-3934-5p downregulation may induce apoptosis and inhibit neuroblastoma cell viability. However, these effects were reversed via TP53INP1-siRNA. Data from the current study indicates that the miR-3934-5p/TP53INP1 axis may be a novel therapeutic target for neuroblastoma treatment.

Aberrant expression of miR‑130a‑3p in ankylosing spondylitis and its role in regulating T‑cell survival

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease. MicroRNAs (miRNAs) are a group of endogenous small non‑coding RNAs that regulate target genes, and play a critical role in many biological processes. However, the underlying mechanism of specific miRNA, miR‑130a‑3p, in AS remains largely unknown. Therefore, the present study aimed to explore the underlying mechanism of miR‑130a‑3p in the development of AS. In the present study, it was revealed that miR‑130a‑3p was downregulated in T cells from HLA‑B27‑positive AS patients compared with the HLA‑B27‑negative healthy controls. Next, bioinformatics software TargetScan 7.2 was used to predict the target genes of miR‑130a‑3p, and a luciferase reporter assay indicated that HOXB1 was the direct target gene of miR‑130a‑3p. Furthermore, it was determined that HOXB1 expression was upregulated in T cells from HLA‑B27‑positive AS patients. In addition, the results of the present study indicated that miR‑130a‑3p inhibitor significantly inhibited cell proliferation ability and induced cell apoptosis of Jurkat T cells, while the miR‑130a‑3p mimic promoted proliferation ability and inhibited cell apoptosis of Jurkat T cells. Notably, all the effects of the miR‑130a‑3p mimic on Jurkat T cells were reversed by HOXB1‑plasmid. Collectively, our data indicated that miR‑130a‑3p was decreased in T cells from AS patients and it could regulate T‑cell survival by targeting HOXB1.

Aberrant expression and mechanism of miR-130b-3p/phosphatase and tensin homolog in nephroblastoma in children

Nephroblastoma is the most common renal tumor in children. Abnormal expression of microRNAs (miRs) has been reported to be involved in the progression of various types of cancers. However, the role and underlying mechanism of miR-130b-3p in nephroblastoma remains unknown. Therefore, the present study aimed to explore the role and possible mechanism of miR-130b-3p in nephroblastoma in children. The present study identified that miR-130b-3p was highly expressed in nephroblastoma tissues obtained from children with nephroblastoma. To better understand the functions and the molecular mechanisms of miR-130b-3p in nephroblastoma, TargetScan was used to identify the potential targets of miR-130b-3p. Phosphatase and tensin homolog (PTEN), was identified as a target gene of miR-130b-3p, and it was observed to be downregulated in nephroblastoma. Further analysis indicated that miR-130b-3p inhibitor could significantly reduce cell proliferation, induce apoptosis and suppress the Akt/nuclear factor-κB/survivin signaling pathway in nephroblastoma cells. Notably, all these effects of miR-130b-3p on nephroblastoma cells were reversed by PTEN-small interfering RNA. In summary, the present study suggested that the miR-130b-3p/PTEN axis could serve a critical role in the progression and development of nephroblastoma. It also suggests that miR-130b-3p might be a valuable clinical biomarker and therapeutic target for nephroblastoma in children.

Lidocaine inhibits the progression of retinoblastoma in vitro and in vivo by modulating the miR‑520a‑3p/EGFR axis

Retinoblastoma (RB) is a common malignant tumor in children. Lidocaine is a local anesthetic and anti-arrhythmic drug, and has been reported to possess anti-tumor properties. MicroRNAs (miRs) are a group of endogenous small noncoding RNAs that have important roles in various biological processes via actions on target genes. The aim of the present study was to investigate the effect of lidocaine on retinoblastoma in vitro and in vivo. CCK-8 assay and flow cytometry assay were used to measure cell viability and apoptosis. The relationship between miR-520a-3p and EGFR was predicted and confirmed by TargetScan and dual-luciferase reporter assay. For in vivo study, tumor xenograft was performed. In addition, gene and protein expression was detected using reverse transcription-quantitative polymerase chain reaction and western blotting respectively. In the present study, it was observed that lidocaine inhibited the proliferation and induced the apoptosis of RB cells. miR-520a-3p was reported to be downregulated in RB tissues and cell lines; treatment with lidocaine increased the expression of miR-520a-3p in RB cells. The human epidermal growth factor receptor (EGFR) was identified as a direct target of miR-520a-3p, and its expression was negatively associated with that of miR-520a-3p. Additionally, EGFR was upregulated in RB tissues and cell lines; treatment with lidocaine decreased the expression of EGFR in RB cells. Furthermore, compared with treatment with lidocaine alone, the combination of transfection with miR-520a-3p inhibitor and lidocaine treatment significantly decreased the expression of miR-520a-3p, increased EGFR expression, promoted RB cell proliferation and reduced the apoptosis of cells in vitro, and increased tumor volume and weight in vivo. The results indicated that lidocaine reduced the proliferation and induced the apoptosis of RB cells by decreasing EGFR expression via the upregulation of miR-520a-3p, suggesting that the miR-520a-3p/EGFR axis may be a novel therapeutic target in the treatment of RB.

miR‑148a modulates the viability, migration and invasion of oral squamous cell carcinoma cells by regulating HLA‑G expression

Oral squamous cell carcinoma (OSCC) is a common malignancy of the oral and maxillofacial regions. MicroRNAs (miRs) are a group of endogenous small noncoding RNAs that inhibit gene expression by binding to the mRNA of target genes, and serve important roles in numerous biological processes. Reverse transcription-quantitative polymerase chain reaction and western blotting were used to detect gene and protein expression levels, respectively. Cell proliferation, migration and invasion were detected using MTT, wound healing and Matrigel assays, respectively. The association between miR-148a and human leukocyte antigen-G (HLA-G) was analyzed using Targetscan and Luciferase reporter assays. In the present study, miR-148a was revealed to be significantly downregulated in OSCC cells. To further investigate the functions of miR-148a in OSCC, the viability, migration, and invasive abilities of SCC-9 cells were investigated following transfection with miR-148a mimics or miR-148a inhibitor. It was revealed that transfection with miR-148a mimics significantly reduced the viability, migration and invasion of cells, whereas miR-148a inhibitor significantly enhanced these properties. In addition, HLA-G was identified as a direct target of miR-148a and demonstrated to be downregulated in OSCC cells. Furthermore, it was revealed that transfection with miR-148a mimics decreased the expression levels of HLA-G mRNA and protein in SCC-9 cells, whereas transfection with miR-148a inhibitor increased the expression of HLA-G mRNA and protein. The results indicated that there was an association between miR-148a and HLA-G expression, and suggested that miR-148a may be a potential target in the treatment of OSCC.

Regulation of BTG3 by microRNA-20b-5p in non-small cell lung cancer

The present study aimed to evaluate microRNA- 20b-5p (miR-20b-5p) expression in non-small cell lung cancer (NSCLC), and investigate the effects of miR-20b-5p expression on NSCLC cell proliferation and migration. Reverse transcription-quantitative polymerase chain reaction was performed to measure the expression level of miR-20b-5p in NSCLC tissues and cell lines. Cell Counting Kit-8 and wound healing assays were used to measure cell proliferation and migration. A dual-luciferase reporter assay was performed to validate B-cell translocation gene 3 (BTG3) as a target of miR-20b-5p. It was identified that the expression level of miR-20b-5p is elevated in NSCLC tissues and cell lines. miR-20b-5p overexpression was revealed to promote NSCLC cell proliferation and migration. Furthermore, BTG3 was identified as a direct target of miR-20b-5p, and BTG3 overexpression reversed a miR-20b-5p mimic-induced increase in cell proliferation and migration. In summary, the present study revealed that miR-20b-5p promotes NSCLC cell proliferation and migration by targeting BTG3, which may assist with the development of a novel therapeutic target for the treatment of NSCLC.

CircDOCK1 suppresses cell apoptosis via inhibition of miR‑196a‑5p by targeting BIRC3 in OSCC

Oral squamous cell carcinoma (OSCC) is the most frequent oral cancer in the world, accounting for more than 90% of all oral cancer diagnosis. Circular RNAs (circRNAs) are large types of non-coding RNAs, demonstrating a great capacity of regulating the expression of genes. However, most of the functions of circRNAs are still unknown. Recent research revealed that circRNAs could serve as a miRNA-sponge, consequently regulating the expression of target genes indirectly, including oncogenes. In this study, we built an apoptotic model with TNF-α, and then we confirmed a circRNA associated with the apoptosis of OSCC cells, circDOCK1 by comparing the expression profile of circRNAs in an apoptotic model with that in untreated OSCC cells. We ascertained the presence of circDOCK1 with qRT-PCR and circRNA sequencing. The knockdown of the expression of circDOCK1 led to the increase of apoptosis. Utilizing multiple bioinformatics methods, we predicted the interactions among circRNAs, miRNAs and genes, and built the circDOCK1/miR-196a-5p/BIRC3 axis. Both the silencing of circDOCK1 with small interfering RNA and the upregulation of the expression of miR-196a-5p with mimics led OSCC cells to increase apoptosis and decrease BIRC3 formation. We further confirmed this outcome by comparing the expression of circDOCK1, miR-196a-5p and BIRC3 in oral squamous carcinoma tissue with those in para-carcinoma tissue, and examining the expression profile of circRNAs in oral squamous carcinoma tissue and para-carcinoma tissue with microarray. Our results demonstrated that circDOCK1 regulated BIRC3 expression by functioning as a competing endogenous RNA (ceRNA) and participated in the process of OSCC apoptosis. Thus, we propose that circDOCK1 could represent a novel potential biomarker and therapeutic target of OSCC.

ghr-miR5272a-mediated regulation of GhMKK6 gene transcription contributes to the immune response in cotton

Fusarium wilt is a major biotic stress affecting the productivity of cotton (Gossypium hirsutum). Although mitogen-activated protein kinase (MAPK) cascades play critical roles in plant disease resistance, their intricate regulation under fungal stress remains unclear, especially with regards to microRNA-mediated regulation of MAPK gene expression. In this study, we report that the MAPK kinase gene GhMKK6 and ghr-miR5272a work together in cotton resistance to Fusarium wilt. Silencing GhMKK6 in cotton decreased resistance to F. oxysporum by repressing the expression of known disease-resistance genes. Furthermore, although GhMKK6 played a positive role in disease resistance, excessive GhMKK6 activation caused an excessive hypersensitive response. ghr-miR5272a, a major regulator, prevents this excessive response by regulating GhMKK6 expression. ghr-miR5272a targets the GhMKK6 3'-untranslated region in cotton. Overexpressing miR5272a decreased the expression of GhMKK6 and disease-resistance genes, and increased sensitivity to F. oxysporum, yielding a similar phenotype to GhMKK6-silenced cotton. Overall, these results demonstrate that the ghr-miR5272a-mediated regulation of GhMKK6 expression contributes to the immune response in cotton, and reveal a new feedback loop mechanism in plant disease response.

Downregulation of miR‑146a promotes proliferation and migration of AOB‑treated embryoid body via PDGFRA induction

Antioxidant of bamboo leaves (AOB) has been proven to have antioxidant activity and an inhibitory effect on free radicals that induce deterioration of macromolecules. The multi‑target regulation of microRNAs (miRs) in the complicated process of vasculogenesis and angiogenesis lead to the use of miRNA therapy in vascular development. In the present study, the role of miRNAs on early embryo vascular development upon AOB stimulation was investigated. For this purpose, mouse embryonic stem cells were spontaneously differentiated as embryoid bodies (EBs) and were examined by phase contrast microscopy. miR‑146a mimic and scramble control were transfected into EBs and potential targets of miR‑146a were predicted. Cell proliferation and migration were detected by cell viability and wound‑healing and migration assays, respectively. Angiogenesis was determined by the Spheroid sprouting assay. It was demonstrated that EBs transfected with miR‑146a mimic had an increased growth rate compared with the control cells. miR‑146a‑transfected cells were very susceptible to AOB treatment. Furthermore, among the predicted miR‑146a targets, platelet‑derived growth factor receptor alpha (PDGFRA) was identified as a bona fide target of miR‑146a. In conclusion, PDGFRA was demonstrated to participate in the modulation of cell migration and proliferation of mouse EBs. The present study expanded the current understanding of AOB biology and elucidated the mechanisms underlying early embryo vascular development upon AOB stimulation.

MiR-34a regulates mitochondrial content and fat ectopic deposition induced by resistin through the AMPK/PPARα pathway in HepG2 cells

Resistin is an adipocyte-derived cytokine and was named for its role in the development of insulin resistance. Increased serum resistin levels are also associated with steatohepatitis and non-alcoholic fatty liver disease. In a previous study, resistin was observed to reduce mitochondrial content and upregulate miR-34a significantly in the liver. In this study, male C57BL/6 mice were injected with agomir-34a or control agomir, and HepG2 cells were transfected with miR-34a mimics or inhibitors to assess their role in resistin-induced fat deposition. The overexpression of miR-34a increased liver and HepG2 cell TAG content, decreased mitochondrial content, changed mitochondrial morphology and impaired mitochondrial function. In contrast, a miR-34a inhibitor significantly restored the TAG content and mitochondrial transmembrane potential. A study of transcriptional regulation revealed that C/EBPβ is essential for upregulating miR-34a by resistin. Furthermore, miR-34a inhibited the PPARα signaling pathway by binding to sites in the 3'UTR of AdipoR2 genes and the AMPK pathway. Consequently, this increased the fat content and decreased the mitochondrial content in HepG2 cells. This paper reveals a novel mechanism for mitochondrial regulation, which suggests that normal mitochondrial content and function is crucial for lipid metabolism in the liver.

miR-9 induces cell arrest and apoptosis of oral squamous cell carcinoma via CDK 4/6 pathway

Oral cancer remains a major public concern with considerable socioeconomic impact in the world, especially in southeast Asia. Despite substantial advancements have been made in treating oral cancer, the five-year survival rate for OSCC remained undesirable, and 35-55% patients developed recurrence within two years even with multimodality therapeutic strategies. Hence, identification of novel biomarkers for diagnosis and evaluating clinical outcome is of vital importance. MicroRNAs are 22-24 nt non-coding RNAs that could bind to 3' UTR of target mRNAs, thereby inducing degradation of mRNA or inhibiting translation. Due to its implication in regulation of post-transcriptional processes, the role of miRNAs in malignancies has been extensively studied, among which the discovery of functional miR-9 in oral squamous cell carcinoma (OSCC) remained to be elucidated. We first demonstrated that miR-9 was down-regulated in 21 OSCC patients, and we further found that forced expression of miR-9 could result in deterred cell proliferation and decreased ability to migrate and form colonies. Flow cytometry displayed cell-cycle arrested at G0/G1 phase. We next used Targetscan to predict target genes of miR-9. CDK6, a protein highly implicated in cell cycle control, was chosen for verification. Down-regulation of CDK6 and Cyclin D1 in Tca8113 transfected with miR-9 mimics indicate that the complex formed by both proteins may be the effector of the antiproliferative function of miR-9 in OSCCs. Considering small molecules are developed to target CDK4/6, our finding may provide valuable scientific evidence for research and development of therapies and diagnostic methodology in OSCCs.

MicroRNAs: A novel potential biomarker for diagnosis and therapy in patients with non-small cell lung cancer

BACKGROUND

Lung cancer is still one of the most serious causes of cancer-related deaths all over the world. MicroRNAs (miRNAs) are defined as small non-coding RNAs which could play a pivotal role in post-transcriptional regulation of gene expression. Increasing evidence demonstrated dysregulation of miRNA expression associates with the development and progression of NSCLC.

AIMS

To emphasize a variety of tissue-specific miRNAs, circulating miRNAs and miRNA-derived exosomes could be used as potential diagnostic and therapeutic biomarkers in NSCLC patients.

MATERIALS & METHODS

In the current review, we paid attention to the significant discoveries of preclinical and clinical studies, which performed on tissue-specific miRNA, circulating miRNA and exosomal miRNA. The related studies were obtained through a systematic search of Pubmed, Web of Science, Embase.

RESULTS

A variety of tissue-specific miRNAs and circulating miRNAs with high sensitivity and specificity which could be used as potential diagnostic and therapeutic biomarkers in NSCLC patients. In addition, we emphasize that the miRNA-derived exosomes become novel diagnostic biomarkers potentially in these patients with NSCLC.

CONCLUSION

MiRNAs have emerged as non-coding RNAs, which have potential to be candidates for the diagnosis and therapy of NSCLC.

Identification and characterization of the expression profile of the microRNAs in the Amazon species Colossoma macropomum by next generation sequencing

Colossoma macropomum is a resistant species native of Amazonas and Orinoco river basins. It is regarded as the second largest finfish of Solimões and Amazon rivers, representing a major fishery resource in Amazonas and an important species in tropical aquaculture. MicroRNAs are non-coding endogenous riboregulators of nearly 22 nucleotides that play a key role in post-transcriptional gene regulation of several organisms. We analyzed samples of liver and skin from specimens of C. macropomum using next generation sequencing. The dataset was evaluated using computational programs to check the quality of sequences, identification of miRNAs, as well as to evaluate the expression levels of these microRNAs and interaction of target genes. We identified 279 conserved miRNAs, being 257 from liver and 272 from skin, with several miRNAs shared between tissues, with divergence in the number of reads. The strands miR-5p and miR-3p were observed in 72 miRNAs, some of them presenting a higher number of 3p reads. The functional annotation of the most expressed miRNAs resulted in 27 pathways for the liver and skin mainly related to the "biological processes" domain. Based on the identified pathways, we visualized a large gene network, suggesting the regulation of selected miRNA over this interactive dataset. We were able to identify and characterize the expression levels of miRNAs in two tissues of great activity in C. macropomum, which stands out as the beginning of several studies that can be carried out to elucidate the influence of miRNAs in this species and their applicability as biotechnological tools.

MicroRNA-152 inhibits tumor cell growth by directly targeting RTKN in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common form of adult liver cancer and accounts for approximately 90% of all cases of primary liver cancer annually. Rhotekin (RTKN), which functions as a cancer promoter, can be frequently detected in many human cancers, including gastric cancer, colorectal carcinoma and bladder carcinoma. The aim of this study was to investigate the role of RTKN in HCC. Using HCC cells and tissues from patients with liver cancer, we demonstrated that RTKN was significantly increased in HCC. To examine the effect of RTKN on HCC, RTKN overexpressed or silenced HepG2 and Hep3B cells were constructed. Cell proliferation and apoptosis were measured by RT-PCR and flow cytometry. The results showed that RTKN can function as an oncogene and promote the proliferation, while inhibiting apoptosis, of HepG2 and Hep3B cells. Furthermore, we identified that RTKN is a direct gene target of miR-152. miR-152 can reverse the growth promoting effect of RTKN on HCC cells through G2/M phase arrest and nuclear factor-κB (NF-κB) signal inhibition. In conclusion, our research identified that miRNA-152 can inhibit tumor cell growth by targeting RTKN in HCC.

Downregulation of miR-18a induces CTGF and promotes proliferation and migration of sodium hyaluronate treated human corneal epithelial cells

Properly controlled corneal epithelial wound healing is critical for health of cornea, which involves cell proliferation, migration, anchoring and differentiation. Sodium hyaluronate (SH) has been proven to exert beneficial pharmacological effect on corneal wound healing, though the underlying mechanism remained open to investigation. MicroRNAs (miRNAs) are small single-stranded RNAs that could bind to 3'UTR of mRNAs of target genes. The multi-target regulation of miRNAs may favor treatment of corneal wound given the complicated processes implicated in the healing process, which has inspired initiatives to develop miRNA therapy in corneal wound healing. In this light, we used miRNAs profiling to detect whether miRNAs are also implicated in the mechanism underlying the stimulatory effect of SH on corneal epithelial wound healing. We found miR-18a was most susceptible to SH treatment, the target prediction of which were enriched in a bunch of pathways implicated in corneal wound healing. Connective tissue growth factor (CTGF) was found to be overrepresented in most significant enriched pathways and was experimentally confirmed as a bona fide target of miR-18a, which modulated cell migration and proliferation of human corneal epithelial cells.

Study on Expression Modes and Cleavage Role of miR156b/c/d and its Target Gene Vv-SPL9 During the Whole Growth Stage of Grapevine

miR156 regulates the expression of its target SPL (PROMOTER BINDING-LIKE) genes during flower and fruit development, diverse developmental stage transitions, especially from vegetative to reproductive growth phases, by cleaving the target mRNA SPL of one plant-specific transcription factor. However, systematic reports on grapevine have yet to be presented. Here, the precise sequence of miR156 (vvi-miR156b/c/d) in grapevine "Takatsuma" was cloned with a previously cloned grapevine SPL (Vv-SPL9). Expression profiles in 18 grapevine tissues were identified through stem-loop RT-PCR. The interaction mode between vvi-miR156b/c/d and Vv-SPL9 was further validated by detecting the cleavage site and cleavage products of 3'- and 5'-ends via an integrated approach of 5'-RLM-RACE (RNA ligase-mediated 5'-rapid amplification of cDNA ends), 3'-PPM-RACE (poly(A) polymerase-mediated 3'-rapid amplification of cDNA ends), and qRT-PCR (real time reverse transcriptase-polymerase chain reaction). The variation in their cleavage roles in the whole growth stage of grapevine was also systematically investigated. Results showed that vvi-miR156b/c/d exhibited typical temporal-spatial-specific expression levels. The expression levels were higher in vegetative organs, such as leaf, than in reproductive organs, such as tendrils, flowers, and berries. A significant variation was observed during vegetative-to-reproductive transition. The expression patterns of Vv-SPL9 showed the opposite trends with those of vvi-miR156b. We confirmed that the cleavage site was at the 10th site of vvi-miR156b/c/d complementary to Vv-SPL9 in "Takatsuma" grapevine. We also identified the temporal-spatial variation of the cleavage products. This variation can indicate the regulatory function of miR156 on SPL in grapevines. Our findings provide further insights into the functions of vvi-miR156b/c/d and its target Vv-SPL9, and also help enrich our knowledge of small RNA-mediated regulation in grapevine.

The Tomato Spotted Wilt Virus Genome Is Processed Differentially in its Plant Host Arachis hypogaea and its Thrips Vector Frankliniella fusca

Thrips-transmitted tospoviruses are economically important viruses affecting a wide range of field and horticultural crops worldwide. Tomato spotted wilt virus (TSWV) is the type member of the Tospovirus genus with a broad host range of more than 900 plant species. Interactions between these viruses and their plant hosts and insect vectors via RNAi pathways are likely a key determinant of pathogenicity. The current investigation, for the first time, compares biogenesis of small RNAs between the plant host and insect vector in the presence or absence of TSWV. Unique viral small interfering RNA (vsiRNA) profiles are evident for Arachis hypogaea (peanut) and Frankliniella fusca (thrips vector) following infection with TSWV. Differences between vsiRNA profiles for these plant and insect species, such as the relative abundance of 21 and 22 nt vsiRNAs and locations of alignment hotspots, reflect the diverse siRNA biosynthesis pathways of their respective kingdoms. The presence of unique vsiRNAs in F. fusca samples indicates that vsiRNA generation takes place within the thrips, and not solely through uptake via feeding on vsiRNAs produced in infected A. hypogaea. The study also shows key vsiRNA profile differences for TSWV among plant families, which are evident in the case of A. hypogaea, a legume, and members of Solanaceae (S. lycopersicum and Nicotiana benthamiana). Distinctively, overall small RNA (sRNA) biogenesis in A. hypogaea is markedly affected with an absence of the 24 nt sRNAs in TSWV-infected plants, possibly leading to wide-spread molecular and phenotypic perturbations specific to this species. These findings add significant information on the host-virus-vector interaction in terms of RNAi pathways and may lead to better crop and vector specific control strategies.

Identification and Characterization of miRNAs in Chondrus crispus by High-Throughput Sequencing and Bioinformatics Analysis

Chondrus crispus, an economically and medicinally important red alga, is a medicinally active substance and important for anti-tumor research. In this study, 117 C. crispus miRNAs (108 conserved and 9 novel) were identified from 2,416,181 small-RNA reads using high-throughput sequencing and bioinformatics methods. According to the BLAST search against the miRBase database, these miRNAs belonged to 110 miRNA families. Sequence alignment combined with homology searching revealed both the conservation and diversity of predicted potential miRNA families in different plant species. Four and 19 randomly selected miRNAs were validated by northern blotting and stem-loop quantitative real-time reverse transcription polymerase chain reaction detection, respectively. The validation rates (75% and 94.7%) demonstrated that most of the identified miRNAs could be credible. A total of 160 potential target genes were predicted and functionally annotated by Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes analysis. We also analyzed the interrelationship of miRNAs, miRNA-target genes and target genes in C. crispus by constructing a Cytoscape network. The 117 miRNAs identified in our study should supply large quantities of information that will be important for red algae small RNA research.

microRNA miR-10b inhibition reduces cell proliferation and promotes apoptosis in non-small cell lung cancer (NSCLC) cells

Lung cancer is one of the most common and serious types of cancer. Till now, the treatment of lung cancer has been unsatisfactory, which is associated with poor prognosis and high mortality. Therefore, there is an urgent requirement to investigate the molecular mechanisms underlying lung tumorigenesis. To study the potential function of miR-10b involved in the regulation of lung tumors, we monitored NSCLC cell behaviour including proliferation, apoptosis and cell cycle using CCK-8 and flow cytometry analysis. Real-time PCR was used to detect the expression levels of miR-10b in 75 NSCLC patients' tissues and Western blot was also used to analyze the expression level of genes correlated with apoptosis in NSCLC cells. miR-10b expression levels were higher in NSCLC tissues compared with an adjacent normal tissue control. Silencing of miR-10b inhibited cancer cell progress by arresting cell cycle progression in the G0/G1 phase and promoted apoptosis in NSCLC cells. Western blot analysis of miR-10b-silenced cells revealed up-regulation of apoptosis-inducing members Fas, FasL, Bax and caspase 3, and down-regulation of apoptosis-inhibiting factors Bcl-2 and PCNA. And, a significant inverse correlation between the level of miR-10b and klotho was observed, which has been demonstrated to be a novel tumor suppressor gene. A further in vivo tumor formation study in nude mice indicated that inhibition of miR-10b in lung cancer cells delayed the progress of tumor formation. These findings indicated that miR-10b might serve as a useful potential target for treatment of NSCLC.

Identification and characterization of microRNAs in Eucheuma denticulatum by high-throughput sequencing and bioinformatics analysis

Eucheuma denticulatum, an economically and industrially important red alga, is a valuable marine resource. Although microRNAs (miRNAs) play an essential role in gene post-transcriptional regulation, no research has been conducted to identify and characterize miRNAs in E. denticulatum. In this study, we identified 134 miRNAs (133 conserved miRNAs and one novel miRNA) from 2,997,135 small-RNA reads by high-throughput sequencing combined with bioinformatics analysis. BLAST searching against miRBase uncovered 126 potential miRNA families. A conservation and diversity analysis of predicted miRNA families in different plant species was performed by comparative alignment and homology searching. A total of 4 and 13 randomly selected miRNAs were respectively validated by northern blotting and stem-loop reverse transcription PCR, thereby demonstrating the reliability of the miRNA sequencing data. Altogether, 871 potential target genes were predicted using psRobot and TargetFinder. Target genes classification and enrichment were conducted based on Gene Ontology analysis. The functions of target gene products and associated metabolic pathways were predicted by Kyoto Encyclopedia of Genes and Genomes pathway analysis. A Cytoscape network was constructed to explore the interrelationships of miRNAs, miRNA-target genes and target genes. A large number of miRNAs with diverse target genes will play important roles for further understanding some essential biological processes in E. denticulatum. The uncovered information can serve as an important reference for the protection and utilization of this unique red alga in the future.

miR-RACE: an effective approach to accurately determine the sequence of computationally identified miRNAs

Computational prediction of microRNAs (miRNAs) is one of the most important approaches in microRNA studies. While validation of the predicted microRNAs' precise sequences is essential for further studies on their biogenesis, evolution, and functions, computational miRNA prediction methods, however, often fail to predict the accurate sequence of the mature miRNA within the precursor at the nucleotide precision level. Here, we depict a highly efficient method for determining the precise sequences of computationally predicted miRNAs. The method combines the generation of miRNA-enriched libraries, with 5'- and 3'-end adaptors being linked to the miRNA molecules, the reverse transcription of small RNAs with an oligo-d(T) anchor primer, two specific 5'- and 3'-miRNA-RACE (miR-RACE) PCR reactions and sequence-directed cloning. The efficiency of this method was demonstrated by the precise sequence validation of computationally predicted miRNAs in citrus, apple, and other fruit crops. Our ongoing research indicates that miR-RACE is also very useful to verify the sequences of putative miRNAs obtained by deep sequencing of small RNA libraries. The protocol of miR-RACE is rapid and can be completed within 2-3 days. miR-RACE should make the bioinformatic prediction of miRNAs more powerful and accurate.

MiR-34a is Involved in the Decrease of ATP Contents Induced by Resistin Through Target on ATP5S in HepG2 Cells

Resistin is associated with metabolic syndrome and deciphering its developmental and molecular mechanisms may help the development of new treatments. MiRNAs serve as negative regulators in many physiological and pathological processes. Here, miRNA microarrays were used to detect differences in expression between resistin-treated and control mice, and results showed miR-34a to be upregulated by resistin. The purpose of this study was to determine whether miR-34a played a role in resistin-induced decrease of ATP contents. Transient transfection of miR-34a mimics was used to overexpress miR-34a and quantitative RT-PCR was used to detect its expression. Western blot analysis was used to determine the rate of expression at the protein level. ATP content was measured using an ATP assay kit. The target gene of miR-34a was analyzed using bioinformatics and confirmed with dual-luciferase report system. MiR-34a was upregulated by resistin in HepG2 cells, and overexpression of miR-34a was found to diminish ATP levels significantly. This study is the first to show that ATP5S is one of the target genes of miR-34a. Resistin diminishes ATP content through the targeting of ATP5S mRNA 3'UTR by miR-34a.

Genome-Wide Mapping and Analysis of Grapevine MicroRNAs and Their Potential Target Genes

MicroRNAs (miRNAs) are single-stranded, nonprotein-coding, endogenously expressed, small RNAs 19 to 25 nucleotides in length. Recognizing the lack of specific and systematic studies on genome-wide mapping of grapevine (Vitis vinifera L.) miRNAs, we conducted genome-wide mapping of Vv-miRNAs (V. vinifera miRNAs), SB-miRNAs (V. vinifera L. 'Summer Black' miRNAs), and Va-miRNAs (V. amurensis Rupr. miRNAs). The mapping results revealed that many of miRNAs located within the intergenic region had independent transcription units. To further validate the mapping results and existence of miRNAs, 12 randomly selected precursors of miRNAs (pre-miRNAs) were successfully cloned and sequenced. Subsequently, 15 conserved and 29 nonconserved intragenic (intronic, exonic) Vv-miRNA genes, 24 nonconserved intragenic SB-miRNA genes, and 23 nonconserved intragenic Va-miRNA genes were labeled on the basis of their locations in host genes, and 15 MIRNA clusters were detected. Interestingly, five miRNA pairs, namely, Vv-MIR395b and Vv-MIR395c, Vv-MIR482 and Vv-MIRC13, Vv-MIR172a and Va-MIR057, SB-MIR024 and Vv-MIRC35, and Vv-MIRC36 and Va-MIR073 were clustered in the host genes GSVIVT01011558001, GSVIVT01008132001, GSVIVT01031524001, GSVIVT01028156001, and GSVIVT01024516001, respectively. To validate the existence of target genes and miRNA-guided cleavage sites, 3'-end product of four predicted target messenger RNAs were amplified by RNA ligase-mediated 5' rapid amplification of cDNA ends. In addition, we also conducted contrastive analysis on the genomic location of miRNAs and their potential target genes. Results showed that the order of priority of miRNA-target interaction may be less closely related with their genomic location. These findings could benefit some further study on grapevine functional genomics and will provide new insights into the regulatory mechanisms and evolution of miRNAs in Vitis species.

Integrated network analysis identifies fight-club nodes as a class of hubs encompassing key putative switch genes that induce major transcriptome reprogramming during grapevine development

We developed an approach that integrates different network-based methods to analyze the correlation network arising from large-scale gene expression data. By studying grapevine (Vitis vinifera) and tomato (Solanum lycopersicum) gene expression atlases and a grapevine berry transcriptomic data set during the transition from immature to mature growth, we identified a category named "fight-club hubs" characterized by a marked negative correlation with the expression profiles of neighboring genes in the network. A special subset named "switch genes" was identified, with the additional property of many significant negative correlations outside their own group in the network. Switch genes are involved in multiple processes and include transcription factors that may be considered master regulators of the previously reported transcriptome remodeling that marks the developmental shift from immature to mature growth. All switch genes, expressed at low levels in vegetative/green tissues, showed a significant increase in mature/woody organs, suggesting a potential regulatory role during the developmental transition. Finally, our analysis of tomato gene expression data sets showed that wild-type switch genes are downregulated in ripening-deficient mutants. The identification of known master regulators of tomato fruit maturation suggests our method is suitable for the detection of key regulators of organ development in different fleshy fruit crops.

MicroRNA-194 inhibits the epithelial-mesenchymal transition in gastric cancer cells by targeting FoxM1

AIM

We hypothesized that miR-194 may control Forkhead box protein M1 (FoxM1) expression in gastric cancer cells and therefore may have therapeutic potential in gastric cancer.

METHODS

The expression level of miR-194 was examined using real-time PCR in human gastric cancer and noncancerous gastric tissues, gastric cancer cell and normal gastric mucosal epithelial cell. We examined whether the miR-194 regulates cell migration and invasion, and the epithelial-mesenchymal transition Phenotype by inhibiting FoxM1 in gastric cancer cells.

RESULTS

The expression of miR-194 was significantly lower in gastric cancer compared with non-cancerous gastric tissues and cells. Exogenous expression of miR-194 inhibited cell migration, invasion, and the epithelial-mesenchymal transition phenotype in gastric cancer cells. Moreover, we discovered a novel post-transcriptional regulatory mechanism of FoxM1 expression that is mediated by miR-194.

CONCLUSION

Our study clearly demonstrates that miR-194 inhibits the acquisition of the EMT phenotype in gastric cancer cells by downregulating FoxM1, thereby inhibiting cell migration and invasion during cancer progression.

A comprehensive genome-wide study on tissue-specific and abiotic stress-specific miRNAs in Triticum aestivum

Productivity of wheat crop is largely dependent on its growth and development that, in turn, is mainly regulated by environmental conditions, including abiotic stress factors. miRNAs are key regulators of gene expression networks involved in diverse aspects of development and stress responses in plants. Using high-throughput sequencing of eight small RNA libraries prepared from diverse abiotic stresses and tissues, we identified 47 known miRNAs belonging to 20 families, 49 true novel and 1030 candidate novel miRNAs. Digital gene expression analysis revealed that 257 miRNAs exhibited tissue-specific expression and 74 were associated with abiotic stresses. Putative target genes were predicted for miRNAs identified in this study and their grouping into functional categories indicated that the putative targets were involved in diverse biological processes. RLM-RACE of predicted targets of three known miRNAs (miR156, miR160 and miR164) confirmed their mRNA cleavage, thus indicating their regulation at post-transcriptional level by the corresponding miRNAs. Mapping of the sequenced data onto the wheat progenitors and closely related monocots revealed a large number of evolutionary conserved miRNAs. Additional expression profiling of some of these miRNAs in other abiotic stresses underline their involvement in multiple stresses. Our findings provide valuable resource for an improved understanding of the role of miRNAs in stress tolerance as well as plant development.

MiRNA-145 is involved in the development of resistin-induced insulin resistance in HepG2 cells

BACKGROUND

Resistin is associated with insulin resistance, and determining its developmental and molecular mechanisms may help the development of novel treatments. MicroRNAs (miRNAs) are involved in many physiological and pathological processes as negative regulators. However, it remains unclear whether miRNAs play a role in resistin-induced insulin resistance. We performed mouse liver miRNA microarrays to analyze the differences in expression between resistin-treated and control mice. Resistin upregulated miR-145 both in vivo and in vitro. Therefore, we aimed to study whether miR-145 played a role in resistin-induced insulin resistance.

METHODS AND RESULTS

We transfected HepG2 cells, and used miR-145 mimics and inhibitors to assess the role of miR-145 in resistin-induced insulin resistance. The overexpression of miR-145 inhibited glucose uptake in HepG2 cells, diminished the phosphorylation of Akt and IRS-1, and induced insulin resistance in hepatocytes. Next, a study of transcriptional regulation revealed that p65 was essential for the upregulation of miR-145 by resistin, and chromatin immunoprecipitation (ChIP) confirmed that p65 could bind to the promoter region of miR-145.

CONCLUSION

miR-145 plays a role in the development of resistin-induced insulin resistance via the p65 pathway.

Transcriptome-wide analysis of dynamic variations in regulation modes of grapevine microRNAs on their target genes during grapevine development

MicroRNAs (miRNAs) play critical regulatory roles mainly through cleaving their target mRNAs or repressing gene translation during plant development. Grapevines are among the most economically important fruit crops with available whole genome sequences. Studies on grapevine miRNAs (Vv-miRNAs) are also widely available. However, studies on the regulation mode of Vv-miRNAs on their target mRNAs during grapevine development have not been studied well, especially at the transcriptome-wide level. Here, six small RNA and mRNA libraries from various grapevine tissues were constructed for Illumina and Degradome sequencing. Subsequently, we systematically analyzed the spatiotemporal variations in the regulation of the target genes of regulation of Vv-miRNAs. In total, 242 known and 132 novel Vv-miRNAs and 193 target mRNAs were identified, including 103 target mRNAs for known and 90 target mRNAs for novel miRNAs, were validated in one or more of the tissues examined. More than 50 % of novel miRNAs were expressed exclusively in the flowers and berries, where they cleaved their target genes in a tissue-specific manner, especially, the breadth of their cleavage sites in flower tissues. Moreover, six novel miRNAs in berries responded to exogenous gibberellin and/or ethylene under a quantitative real time RT-PCR analysis, which confirmed their regulatory functions during berry development. Up to 93.6 % of the known miRNAs were highly conserved in various tissues, where their expression levels exhibited dynamic variations during grapevine development. Significantly, some Vv-miRNA families had one key member that acted as the main regulator of their target genes during grapevine development.