MiR-27a targets sFRP1 in hFOB cells to regulate proliferation, apoptosis and differentiation

RNA-binding protein AZGP1 inhibits epithelial cell proliferation by regulating the genes of alternative splicing in COPD

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) is characterized by high morbidity, disability, and mortality rates worldwide. RNA-binding proteins (RBPs) might regulate genes involved in oxidative stress and inflammation in COPD patients. Single-cell transcriptome sequencing (scRNA-seq) offers an accurate tool for identifying intercellular heterogeneity and the diversity of immune cells. However, the role of RBPs in the regulation of various cells, especially AT2 cells, remains elusive.

MATERIALS AND METHODS

A scRNA-seq dataset (GSE173896) and a bulk RNA-seq dataset acquired from airway tissues (GSE124180) were employed for data mining. Next, RNA-seq analysis was performed in both COPD and control patients. Differentially expressed genes (DEGs) were identified using criteria of fold change (FC ≥ 1.5 or ≤ 1.5) and P value ≤ 0.05. Lastly, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and alternative splicing identification analyses were carried out.

RESULTS

RBP genes exhibited specific expression patterns across different cell groups and participated in cell proliferation and mitochondrial dysfunction in AT2 cells. As an RBP, AZGP1 expression was upregulated in both the scRNA-seq and RNA-seq datasets. It might potentially be a candidate immune biomarker that regulates COPD progression by modulating AT2 cell proliferation and adhesion by regulating the expression of SAMD5, DNER, DPYSL3, GBP5, GBP3, and KCNJ2. Moreover, AZGP1 regulated alternative splicing events in COPD, particularly DDAH1 and SFRP1, holding significant implications in COPD.

CONCLUSION

RBP gene AZGP1 inhibits epithelial cell proliferation by regulating genes participating in alternative splicing in COPD.

The impact of substrate stiffness on morphological, transcriptional and functional aspects in RPE

Alterations in the structure and composition of Bruch's membrane (BrM) and loss of retinal pigment epithelial (RPE) cells are associated with various ocular diseases, notably age-related macular degeneration (AMD) as well as several inherited retinal diseases (IRDs). We explored the influence of stiffness as a major BrM characteristic on the RPE transcriptome and morphology. ARPE-19 cells were plated on soft ( E = 30 kPa ) or stiff ( E = 80 kPa ) polyacrylamide gels (PA gels) or standard tissue culture plastic (TCP). Next-generation sequencing (NGS) data on differentially expressed small RNAs (sRNAs) and messenger RNAs (mRNAs) were validated by qPCR, immunofluorescence or western blotting. The microRNA (miRNA) fraction of sRNAs grew with substrate stiffness and distinct miRNAs such as miR-204 or miR-222 were differentially expressed. mRNA targets of differentially expressed miRNAs were stably expressed, suggesting a homeostatic effect of miRNAs. mRNA transcription patterns were substrate stiffness-dependent, including components of Wnt/beta-catenin signaling, Microphthalmia-Associated Transcription Factor (MITF) and Dicer. These findings highlight the relevance of mechanical properties of the extracellular matrix (ECM) in cell culture experiments, especially those focusing on ECM-related diseases, such as AMD.

LncRNA MEG3 inhibits the proliferation and migration abilities of colorectal cancer cells by competitively suppressing MiR-31 and reducing the binding of MiR-31 to target gene SFRP1

To explore the potential mechanism of long-chain non-coding ribonucleic acid (lncRNA) maternal expression gene 3 (MEG3) in colorectal cancer (CRC). The relationship between MEG3 and miR-31 was detected by dual-luciferase assay. Quantitative polymerase chain reaction was utilized to determine the expression of MEG3 in CRC cell lines. Cell Counting Kit-8 assay was performed to detect cell proliferation. Transwell, cell scratch wound assay, and monoclonal proliferation assay were used to detect the proliferation, migration, and invasion of cells. In addition, cell motility was evaluated by detecting the expression of cellular pseudopodia protein α-actinin via immunofluorescence assay, and cell proliferation and motility were judged by determining the expressions of Ki-67, MMP2 and MMP9 via Western blotting. The effect of MEG3 and miR-31 on the development of colorectal cancer was verified by nude mouse tumor-bearing assay and HE staining. Transient transfection with MEG3 overexpression plasmid revealed that MEG3 inhibited the proliferation and motility of cells. The results of dual-luciferase assay showed that MEG3 could specifically inhibit the expression of miR-31, which inhibits the development of colorectal cancer. Transwell, cell scratch wound assay, and monoclonal proliferation experiment showed that miR-31 enhanced cell proliferation, migration and invasion. MEG3 overexpression plasmid was capable of reversing the proliferation and motility of CRC cells enhanced by miR-31. MEG3 can inhibit the proliferation and motility of CRC cells by competitively suppressing the binding of miR-31 to the target gene SFRP1, thus playing an inhibitory role in the pathogenesis of CRC.

Research progress on the regulation of bone marrow stem cells by noncoding RNAs in adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a common spinal deformity in young women, but its pathogenesis remains unclear. The primary pathogenic factors contributing to its development include genetics, abnormal bone metabolism, and endocrine factors. Bone marrow stem cells (BMSCs) play a crucial role in the pathogenesis of AIS by regulating its occurrence and progression. Noncoding RNAs (ncRNAs) are also involved in the pathogenesis of AIS, and their role in regulating BMSCs in patients with AIS requires further evaluation. In this review, we discuss the relevant literature regarding the osteogenic, chondrogenic, and lipogenic differentiation of BMSCs. The corresponding mechanisms of ncRNA-mediated BMSC regulation in patients with AIS, recent advancements in AIS and ncRNA research, and the importance of ncRNA translation profiling and multiomics are highlighted.

Evaluation of osteogenic induction potency of miR-27a-3p in adipose tissue-derived human mesenchymal stem cells (AD-hMSCs)

BACKGROUND

Bone tissue as a dynamic tissue is able to repair its minor injuries, however, sometimes the repair cannot be completed by itself due to the size of lesion. In such cases, the best treatment could be bone tissue engineering. The use of stem cells in skeletal disorders to repair bone defects has created bright prospects. On the other hand, changes in the expression level of microRNAs (miRs) can lead to the commitment of mesenchymal stem cells (MSCs) to cell lineage. Many studies reported that post-transcriptional regulations by miRNAs are involved in all stages of osteoblast differentiation.

METHOD

After the preparing adipose tissue-derived mesenchymal stem cells, the target cells from the third passage were cultured in two groups, transfected MSCs with miR-27a-3p (DM.C + P) and control group. In different times, 7 and 14 days after culture, differentiation of these cells into osteoblast were measured using various techniques including the ALP test and calcium content test, Alizarin Red staining, Immunocytochemistry technique (ICC). Also, the relative expression of bone differentiation marker genes including Osteonectin (ON), Osteocalcin (OC), RUNX Family Transcription Factor 2 (RUNX2), Collagen type I alpha 1 (COL1) was investigated by real-time RT PCR.

RESULTS

In comparison with control groups, overexpression of miR-27a-3p in transfected cells resulted in a significant increase in the expression of bone markers genes (ON, OC, RUNX2, COL1), alkaline phosphatase (ALP) activity, and calcium content (p < 0.05). In addition, the results obtained from ICC technique showed that osteocalcin protein is expressed at the surface of bone cells. Furthermore, the expression of APC, as a target of miR-27a-3p, decreased in transfected cells.

CONCLUSION

Our data suggest that miR-27a-3p may positively regulates adipose tissue-derived mesenchymal stem cell differentiation into bone by targeting APC and activating the Wnt/b-catenin pathway.

miRNA dysregulation in traumatic brain injury and epilepsy: a systematic review to identify putative biomarkers for post-traumatic epilepsy

Traumatic brain injury (TBI) leads to post-traumatic epilepsy (PTE); hence, both TBI and PTE share various similar molecular mechanisms. MicroRNA (miRNA) is a small noncoding RNA that acts as a gene-silencing molecule. Notably, the dysregulation of miRNAs in various neurological diseases, including TBI and epilepsy, has been reported in several studies. However, studies on commonly dysregulated miRNAs and the regulation of shared pathways in both TBI and epilepsy that can identify potential biomarkers of PTE are still lacking. This systematic review covers the peer-review publications of TBI and database studies of epilepsy-dysregulated miRNAs of clinical studies. For TBI, 290 research articles were identified after screening, and 12 provided data for dysregulated miRNAs in humans. The compiled data suggest that 85 and 222 miRNAs are consecutively dysregulated in TBI and epilepsy. In both, 10 miRNAs were found to be commonly dysregulated, implying that they are potentially dysregulated miRNAs for PTE. Furthermore, the targets and involvement of each putative miRNA in different pathways were identified and evaluated. Additionally, clusters of predicted miRNAs were analyzed. Each miRNA's regulatory role was linked with apoptosis, inflammation, and cell cycle regulation pathways. Hence, these findings provide insight for future diagnostic biomarkers.

MicroRNA-101a enhances trabecular bone accrual in male mice

High-throughput microRNA sequencing was performed during differentiation of MC3T3-E1 osteoblasts to develop working hypotheses for specific microRNAs that control osteogenesis. The expression data show that miR-101a, which targets the mRNAs for the epigenetic enzyme Ezh2 and many other proteins, is highly upregulated during osteoblast differentiation and robustly expressed in mouse calvaria. Transient elevation of miR-101a suppresses Ezh2 levels, reduces tri-methylation of lysine 27 in histone 3 (H3K27me3; a heterochromatic mark catalyzed by Ezh2), and accelerates mineralization of MC3T3-E1 osteoblasts. We also examined skeletal phenotypes of an inducible miR-101a transgene under direct control of doxycycline administration. Experimental controls and mir-101a over-expressing mice were exposed to doxycycline in utero and postnatally (up to 8 weeks of age) to maximize penetrance of skeletal phenotypes. Male mice that over-express miR-101a have increased total body weight and longer femora. MicroCT analysis indicate that these mice have increased trabecular bone volume fraction, trabecular number and trabecular thickness with reduced trabecular spacing as compared to controls. Histomorphometric analysis demonstrates a significant reduction in osteoid volume to bone volume and osteoid surface to bone surface. Remarkably, while female mice also exhibit a significant increase in bone length, no significant changes were noted by microCT (trabecular bone parameters) and histomorphometry (osteoid parameters). Hence, miR-101a upregulation during osteoblast maturation and the concomitant reduction in Ezh2 mediated H3K27me3 levels may contribute to the enhanced trabecular bone parameters in male mice. However, the sex-specific effect of miR-101a indicates that more intricate epigenetic mechanisms mediate physiological control of bone formation and homeostasis.

Tear miRNA expression analysis reveals miR-203 as a potential regulator of corneal epithelial cells

Background

microRNAs (miRNAs) are small noncoding RNAs that negatively regulate gene expression. They are found within cells and in body fluids. Extracellular miRNAs have been shown to associate with the surrounding tissues. Therefore, we predicted that miRNAs in tears may contribute to regulate corneal epithelial cell function. However, information on the miRNA expression profile of tears is limited and the specific functions of tear miRNAs for corneal epithelial cells are still unknown. To study the role of tear miRNAs, we determined which miRNAs are highly expressed in tears and examined the involvement of miRNAs in corneal epithelial cell viability.

Methods

miRNAs extracted from monkey tears and sera were subjected to microarray analysis. miRNAs of which expression levels were higher in tears than in sera were selected, and their expression levels were quantified by quantitative polymerase chain reaction (qPCR). To examine miRNA function, mimics and inhibitors of miRNAs were transfected into human corneal epithelial (HCE-T) cells and incubated for 24 or 48 h. After transfection of miRNA mimics and inhibitors, the viability of HCE-T cells was measured using the water soluble tetrazolium salt (WST) assay, and microarray analysis and qPCR were performed using total RNA extracted from HCE-T cells. siRNAs of the candidate targets for miR-203 were transfected into HCE-T cells and the WST assay was performed. To determine a direct target gene for miR-203, a dual luciferase reporter assay was performed in HCE-T cells using a luciferase reporter plasmid containing 3′-UTR of human IGFBP5.

Results

Microarray and qPCR analyses showed that miR-184 and miR-203 were expressed significantly more highly in tears than in sera (165,542.8- and 567.8-fold, respectively, p < 0.05). Of these two miRNAs, transfection of a miR-203 mimic significantly reduced the viability of HCE-T cells (p < 0.05), while a miR-203 inhibitor significantly increased this viability (p < 0.05). miR-203 mimic downregulated insulin-like growth factor-binding protein 5 (IGFBP5) and nuclear casein kinase and cyclin-dependent kinase substrate 1 (NUCKS1), while miR-203 inhibitor upregulated these two genes. Transfection of IGFBP5-siRNA decreased the viability of HCE-T cells. miR-203 mimic significantly diminished the luciferase reporter activity.

Conclusions

In this study, we identified miRNAs that are highly expressed in tears, and the inhibition of miR-203 increases the viability of corneal epithelial cells. Our results suggest that miR-203 contributes to regulating the homeostasis of corneal epithelial cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02141-9.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Inhibit Osteoporosis via MicroRNA-27a-Induced Inhibition of DKK2-Mediated Wnt/β-Catenin Pathway

Osteoporosis (OP) is a systemic skeletal disease that promotes bone fragility and the risk of fractures. Recent studies have shown the relevance of microRNAs (miRNAs) in the development of OP. This study aimed to evaluate the possible mechanisms of action underlying miR-27a loaded by mesenchymal stem cell (MSC)-derived extracellular vesicles (MSC-EVs) in OP. Serum samples from OP patients and normal controls were collected for miRNA microarray analysis. The expression of filtered miRNA was upregulated in osteoblasts (OB) and osteoclasts (OCs) for biological activity assessment. After developing OP mice using ovariectomy (OVX) and confirming OP, the miR-27a expression level was upregulated in mice by MSC-EV application. Dual-luciferase assays were conducted to validate the relationship between miR-27a and DKK2 expression. The poor expression of miR-27a was observed in patients with OP. miR-27a increased the expression of OB markers, the number of ALP-positive cells, and the number of calcium nodules in OCs. In OVX mice, miR-27a increased bone density, improved bone structure damage recovery, decreased the levels of bone resorption markers, and decreased OC number. miR-27a transmitted by MSC-EVs interacted with DKK2. MSC-EVs exerted the same protective effects as miR-27a on OP, whereas miR-27a inhibitor abolished the attenuating effects of MSC-EVs. In contrast, DKK2 depletion reversed the stimulatory effects of the miR-27a inhibitor on OP. The Wnt/β-catenin pathway was activated upon MSC-EV application and DKK2 silencing and was impaired upon the downregulation of the expression of miR-27a. MSC-EVs are effective in preventing mouse OP. This mechanism is mediated by the miR-27a/DKK2/Wnt/β-catenin signaling pathway.

MicroRNAs Regulation in Osteogenic Differentiation of Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are a kind of pluripotent stem cell with the potential of self-renewal and multidirectional differentiation. They can be obtained from a variety of tissues and can differentiate into a variety of cell types under different induction conditions, including osteoblasts. Because of this osteogenic property, MSCs have attracted much attention in the treatment of bone metabolism-related diseases. MicroRNAs (miRNAs), as an epigenetic factor, are thought to play an important regulatory role in the process of osteogenic differentiation of MSCs. In recent years, increasingly evidence shows that miRNAs imbalance is involved in the regulation of osteoporosis and fracture. In this review, miRNAs involved in osteogenic differentiation and their mechanisms for regulating the expression of target genes are reviewed. In addition, we also discuss the potential clinical applications and possible directions of this field in the future.

MiR-27a-3p promotes the osteogenic differentiation by activating CRY2/ERK1/2 axis

Background

Osteoporosis seriously disturbs the life of people. Meanwhile, inhibition or weakening of osteogenic differentiation is one of the important factors in the pathogenesis of osteoporosis. It was reported that miR-27a-3p reduced the symptoms of osteoporosis. However, the mechanism by which miR-27a-3p in osteogenic differentiation remains largely unknown.

Methods

To induce the osteogenic differentiation in MC3T3-E1 cells, cells were treated with osteogenic induction medium (OIM). RT-qPCR was used to evaluate the mRNA expression of miR-27a-3p and CRY2 in cells. The protein levels of CRY2, Runt-related transcription factor 2 (Runx2), osteopontin (OPN), osteocalcin (OCN) and the phosphorylation level of extracellular regulated protein kinases (ERK) 1/2 in MC3T3-E1 cells were evaluated by western blotting. Meanwhile, calcium nodules and ALP activity were tested by alizarin red staining and ALP kit, respectively. Luciferase reporter gene assay was used to analyze the correlation between CRY2 and miR-27a-3p.

Results

The expression of miR-27a-3p and the phosphorylation level of ERK1/2 were increased by OIM in MC3T3-E1 cells, while CRY2 expression was decreased. In addition, OIM-induced increase of calcified nodules, ALP content and osteogenesis-related protein expression was significantly reversed by downregulation of miR-27a-3p and overexpression of CRY2. In addition, miR-27a-3p directly targeted CRY2 and negatively regulated CRY2. Meanwhile, the inhibitory effect of miR-27a-3p inhibitor on osteogenic differentiation was reversed by knockdown of CRY2 or using honokiol (ERK1/2 signal activator). Furthermore, miR-27a-3p significantly inhibited the apoptosis of MC3T3-E1 cells treated by OIM. Taken together, miR-27a-3p/CRY2/ERK axis plays an important role in osteoblast differentiation.

Conclusions

MiR-27a-3p promoted osteoblast differentiation via mediation of CRY2/ERK1/2 axis. Thereby, miR-27a-3p might serve as a new target for the treatment of osteoporosis.

Prostate Cancer Cell Extracellular Vesicles Increase Mineralisation of Bone Osteoblast Precursor Cells in an In Vitro Model

Simple Summary

Prostate cancer frequently metastasizes to the bone, where it forms primarily osteoblastic lesions. Currently there is no real therapeutic option for this late stage of disease, and understanding prostate cancer-bone interaction and communication is vital. Using a simple in vitro model of os-teoblast differentiation and mineralization, we studied this interaction and observed that prostate cancer cells secreted large quantities of extracellular vesicles containing microRNAs. When ex-posed to the extracellular vesicles, increased osteoblast differentiation and mineralization could be observed, and upon RNA-seq several of these microRNAs were implicated as upstream regulators of the mineralization process. These microRNAs also correlated with poor survival in online analysis of patient datasets. We characterized and validated four genes known to be targeted by microRNA-16, and found that extracellular vesicles could deliver miR-16, and increase minerali-zation.

Abstract

Skeletal metastases are the most common form of secondary tumour associated with prostate cancer (PCa). The aberrant function of bone cells neighbouring these tumours leads to the devel-opment of osteoblastic lesions. Communication between PCa cells and bone cells in bone envi-ronments governs both the formation/development of the associated lesion, and growth of the secondary tumour. Using osteoblasts as a model system, we observed that PCa cells and their conditioned medium could stimulate and increase mineralisation and osteoblasts’ differentiation. Secreted factors within PCa-conditioned medium responsible for osteoblastic changes included small extracellular vesicles (sEVs), which were sufficient to drive osteoblastogenesis. Using MiR-seq, we profiled the miRNA content of PCa sEVs, showing that miR-16-5p was highly ex-pressed. MiR-16 was subsequently higher in EV-treated 7F2 cells and a miR-16 mimic could also stimulate mineralisation. Next, using RNA-seq of extracellular vesicle (EV)-treated 7F2 cells, we observed a large degree of gene downregulation and an increased mineralisation. Ingenuity® Pathway Analysis (IPA^®) revealed that miR-16-5p (and other miRs) was a likely upstream effec-tor. MiR-16-5p targets in 7F2 cells, possibly involved in osteoblastogenesis, were included for val-idation, namely AXIN2, PLSCR4, ADRB2 and DLL1. We then confirmed the targeting and dow-regulation of these genes by sEV miR-16-5p using luciferase UTR (untranslated region) reporters. Conversely, the overexpression of PLSCR4, ADRB2 and DLL1 lead to decreased osteoblastogene-sis. These results indicate that miR-16 is an inducer of osteoblastogenesis and is transmitted through prostate cancer-derived sEVs. The mechanism is a likely contributor towards the for-mation of osteoblastic lesions in metastatic PCa.

MicroRNAs Modulate Signaling Pathways in Osteogenic Differentiation of Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) have been identified in many adult tissues and they have been closely studied in recent years, especially in view of their potential use for treating diseases and damaged tissues and organs. MSCs are capable of self-replication and differentiation into osteoblasts and are considered an important source of cells in tissue engineering for bone regeneration. Several epigenetic factors are believed to play a role in the osteogenic differentiation of MSCs, including microRNAs (miRNAs). MiRNAs are small, single-stranded, non-coding RNAs of approximately 22 nucleotides that are able to regulate cell proliferation, differentiation and apoptosis by binding the 3' untranslated region (3'-UTR) of target mRNAs, which can be subsequently degraded or translationally silenced. MiRNAs control gene expression in osteogenic differentiation by regulating two crucial signaling cascades in osteogenesis: the transforming growth factor-beta (TGF-β)/bone morphogenic protein (BMP) and the Wingless/Int-1(Wnt)/β-catenin signaling pathways. This review provides an overview of the miRNAs involved in osteogenic differentiation and how these miRNAs could regulate the expression of target genes.

Oncogenic miR-27a delivered by exosomes binds to SFRP1 and promotes angiogenesis in renal clear cell carcinoma

Exosomes derived from cancer cells have emerged as important mediators of malignant phenotypes of tumors, being involved in the transmission of biological signals between cells. Herein, we intended to clarify the role of exosome-mediated transfer of oncogenic microRNA-27a (miR-27a) in angiogenesis of renal clear cell carcinoma (RCCC). Through bioinformatics analysis, we identified the differentially expressed genes of RCCC and predicted miRNAs targeting SFRP1. We manipulated the expression of miR-27a and/or SFRP1 in RCCC cells to explore their roles in angiogenesis through Cell Counting Kit-8 (CCK-8), Transwell, and Matrigel tubule formation assays. miR-27a loaded in exosomes was overexpressed and downregulated in vitro and in vivo to verify its effect on angiogenesis. SFRP1 was poorly expressed and miR-27a was highly expressed in RCCC tissues, showing a negative correlation. Dual-luciferase assay verified that miR-27a targeted and downregulated SFRP1 expression. Notably, miR-27a enhanced angiogenesis by downregulating SFRP1 expression. miR-27a-loaded exosomes can be delivered from RCCC cells to human umbilical vein endothelial cells (HUVECs). In vitro and in vivo experiments substantiated that miR-27a-loaded exosomes from RCCC cells repressed SFRP1, augmenting the viability, migration, and angiogenesis of RCCC cells. Together, RCCC-derived miR-27a-loaded exosomes inhibit SFRP1 expression and accelerate tumor angiogenesis in RCCC.

miR‑27a‑3p negatively regulates osteogenic differentiation of MC3T3‑E1 preosteoblasts by targeting osterix

Osteoporosis is a complex multifactorial disorder characterized by microarchitectural deterioration, low bone mass, and increased risk of fractures or broken bones. Balanced bone remodeling is tightly regulated by the differentiation, activity and apoptosis of bone-forming osteoblasts and bone-resorbing osteoclasts. MicroRNAs (miRs) are dysregulated in osteoporosis, but whether they control osteogenic differentiation and skeletal biology, or could serve as therapeutic targets remains to be elucidated. The present study identified miR-27a-3p as a critical suppressor of osteoblastogenesis. Bioinformatics analysis and luciferase reporter assays demonstrated that miR-27a-3p directly targeted and controlled the expression of osterix (Osx), an early response gene essential for bone formation, through its 3′-untranslated region. miR-27a-3p functionally inhibited the differentiation of preosteoblasts by decreasing Osx expression, which synergistically contributed to bone formation. miR-27a-3p level was significantly decreased during osteogenic differentiation and increased in the serum of patients with osteoporosis. Together, miR-27a-3p contributed to diminished osteogenic function during osteogenic differentiation and might thus serve as a therapeutic target and diagnostic biomarker for osteoporosis.

Knockdown of LncRNAZFAS1 suppresses cell proliferation and metastasis in non-small cell lung cancer

To evaluate the effects of LncRNAZFAS1 on cell proliferation and tumor metastasis in non-small cell lung cancer (NSCLC), we detected the expression level of LncRNAZFAS1 in NSCLC-related tissues and cells. qRT-PCR results revealed that LncRNAZFAS1 in tumor tissues was significantly higher than that in normal lung tissue, especially significantly up-regulated in stage III / IV and in metastatic NSCLC tissues. LncRNAZFAS1 expression was dramatically up-regulated in 4 NSCLC-related cells (A549, SPC-A1, SK-MES-1, and NCI-H1299), with having the highest expression level in A549 cells. Furthermore, we implemented a knockdown of LncRNAZFAS1 in A549 cells, and the results of CCK8 and Transwell assays suggested that knockdown of LncRNAZFAS1 significantly inhibited NSCLC cell proliferation and metastasis. Next, we constructed a tumor xenograft model to evaluate the effect of LncRNAZFAS1 on the NSCLC cell proliferation in vivo. The results indicated that knockdown of LncRNAZFAS1 dramatically inhibited A549 cells proliferation and repressed tumor growth. Additionally, knockdown of LncRNAZFAS1 drastically weakened the expressions of MMP2, MMP9 and Bcl-2 proteins, whereas noticeably strengthened the expression of BAX protein. Our results altogether suggest that knockdown of LncRNAZFAS1 has a negative effect on the proliferation and metastasis of NSCLC cell, which implying LncRNAZFAS1 is a potential unfavorable biomarker in patients with NSCLC.

The Role of Carcinogenesis-Related Biomarkers in the Wnt Pathway and Their Effects on Epithelial-Mesenchymal Transition (EMT) in Oral Squamous Cell Carcinoma

As oral squamous cell carcinoma (OSCC) can develop from potentially malignant disorders (PMDs), it is critical to develop methods for early detection to improve the prognosis of patients. Epithelial-mesenchymal transition (EMT) plays an important role during tumor progression and metastasis. The Wnt signaling pathway is an intercellular pathway in animals that also plays a fundamental role in cell proliferation and regeneration, and in the function of many cell or tissue types. Specific components of master regulators such as epithelial cadherin (E-cadherin), Vimentin, adenomatous polyposis coli (APC), Snail, and neural cadherin (N-cadherin), which are known to control the EMT process, have also been implicated in the Wnt cascade. Here, we review recent findings on the Wnt signaling pathway and the expression mechanism. These regulators are known to play roles in EMT and tumor progression, especially in OSCC. Characterizing the mechanisms through which both EMT and the Wnt pathway play a role in these cellular pathways could increase our understanding of the tumor genesis process and may allow for the development of improved therapeutics for OSCC.

Role of Secreted Frizzled-Related Protein 1 in Early Mammary Gland Tumorigenesis and Its Regulation in Breast Microenvironment

In mice, the lack of secreted frizzled-related protein 1 (SFRP1) is responsible for mammogenesis and hyperplasia, while, in bovines, its overexpression is associated with post-lactational mammary gland involution. Interestingly, there are no reports dealing with the role of SFRP1 in female involution. However, SFRP1 dysregulation is largely associated with human tumorigenesis in the literature. Indeed, the lack of SFRP1 is associated with both tumor development and patient prognosis. Considering the increased risk of breast tumor development associated with incomplete mammary gland involution, it is crucial to demystify the "grey zone" between physiological age-related involution and tumorigenesis. In this review, we explore the functions of SFRP1 involved in the breast involution processes to understand the perturbations driven by the disappearance of SFRP1 in mammary tissue. Moreover, we question the presence of recurrent microcalcifications identified by mammography. In bone metastases from prostate primary tumor, overexpression of SFRP1 results in an osteolytic response of the tumor cells. Hence, we explore the hypothesis of an osteoblastic differentiation of mammary cells induced by the lack of SFRP1 during lobular involution, resulting in a new accumulation of hydroxyapatite crystals in the breast tissue.

MicroRNAs in breast cancer: Roles, functions, and mechanism of actions

Breast cancer is one of the most lethal malignancies in women in the world. Various factors are involved in the development and promotion of the malignancy; most of them involve changes in the expression of certain genes, such as microRNAs (miRNAs). MiRNAs can regulate signaling pathways negatively or positively, thereby affecting tumorigenesis and various aspects of cancer progression, particularly breast cancer. Besides, accumulating data demonstrated that miRNAs are a novel tool for prognosis and diagnosis of breast cancer patients. Herein, we will review the roles of these RNA molecules in several important signaling pathways, such as transforming growth factor, Wnt, Notch, nuclear factor-κ B, phosphoinositide-3-kinase/Akt, and extracellular-signal-regulated kinase/mitogen activated protein kinase signaling pathways in breast cancer.

Inhibition of long non-coding RNA-AWPPH decreases osteosarcoma cell proliferation, migration and invasion

Long non-coding RNAs (lncRNAs) serve a crucial role in various types of cancer. The lncRNA AWPPH has been reported to promote hepatocellular carcinoma and bladder cancer progression. However, to the best of our knowledge, the biological roles of AWPPH in osteosarcoma (OS) remain unclear. In the present study, the levels of AWPPH in OS tissues and cell lines were determined by reverse transcription-quantitative polymerase chain reaction. An MTT assay was used to detect OS cell proliferation. The levels of proteins associated with the PI3K/Akt signaling pathway and apoptosis were determined by western blotting. Wound-healing and Transwell assays were conducted to determine cell migration and invasion, respectively. The results demonstrated that AWPPH was highly expressed in OS tissues and cells. Functional analyses revealed that AWPPH depletion significantly inhibited OS cell proliferation and migration, and promoted OS cell apoptosis. Furthermore, AWPPH downregulation significantly inhibited the PI3K/AKT pathway. The present study demonstrated that AWPPH was highly expressed in OS, and that AWPPH promoted OS cell proliferation and migration, and inhibited OS cell apoptosis, which may be mediated by PI3K/AKT pathway activation.

Wnt signaling pathway in osteoporosis: Epigenetic regulation, interaction with other signaling pathways, and therapeutic promises

Wnt is a major signaling pathway involved in multifaceted roles of various biological processes. Bones are dynamic tissues which are able to remodel and maintain the tissue homeostasis. Wnt signaling cascade leads to the promotion of bone formation and suppression of bone resorption, leading to a balance in bone remodeling. Recent evidence has reinforced the inevitable role of Wnt signaling in osteoporosis. The complex genetic and epigenetic regulations of Wnt signaling factors and their interaction with other master signaling pathways such as TGF-β, BMP, PI3K/AKT, and Hedgehog outline their importance in diagnosis and treatment of osteoporosis. In this review, we highlighted the recent advances in function of Wnt signaling-related epigenetic regulation, different signaling pathways interacting with Wnt, and their roles in osteoporosis. Finally, we discussed novel promises in molecular targeted therapy of osteoporosis.

Silencing microRNA-27a inhibits proliferation and invasion of human osteosarcoma cells through the SFRP1-dependent Wnt/β-catenin signaling pathway

Osteosarcoma is the most common malignant tumor of bone with a high potential for metastasis. Importantly, microRNA-27a (miR-27a) is involved in the progression of osteosarcoma. The present study aims to discuss the effects of miR-27a and its target gene secreted frizzled related protein 1 (SFRP1) on proliferation and invasion of human osteosarcoma cells via Wnt/β-catenin signaling pathway. The expression of miR-27a and SFRP1 in osteosarcoma tissues and cells was detected, followed by identification of their relations. Subsequently, miR-27a mimic, miR-27a inhibitor, or siRNA against SFRP1 were introduced into cells (HOS and U2OS) to investigate their role in cell proliferation and invasion. The expression of Wnt/β-catenin signaling pathway-related gene was analyzed to further uncover the regulatory mechanism of miR-27a. The osteosarcoma tissues and cells exhibited elevated miR-27 expression and reduced SFRP1 expression. SFRP1 was verified to be a target gene of miR-27a. Meanwhile, silenced miR-27a inhibited proliferation and invasion of human osteosarcoma cells. Finally, silencing miR-27a inhibited the activation of Wnt/β-catenin signaling pathway, evidenced by reduced β-catenin expression. Our study draws a conclusion that silencing miR-27a dampens osteosarcoma progression, which might be achieved through the inactivation of the Wnt/β-catenin signaling pathway by up-regulating SFRP1.

Relationship between microRNA-27a and efficacy of neoadjuvant chemotherapy in gastric cancer and its mechanism in gastric cancer cell growth and metastasis

Objective: The aim of the present study is to investigate the relationship between microRNA-27a (miR-27a) and the efficacy of neoadjuvant chemotherapy in gastric cancer (GC) and its mechanism in the growth and metastasis of GC cells.

Methods: The expression of miR-27a in serum of 74 GC patients received neoadjuvant chemotherapy was detected by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Clinical value and prognosis of miR-27a expression in predicting the efficacy of neoadjuvant chemotherapy in GC were evaluated. Besides, GC cells with low miR-27a expression were transfected with miR-27a mimics, and cells with high miR-27a expression were transfected with miR-27a inhibitors and secreted frizzled-related protein 1 (SFRP1) siRNA. A series of experiments were applied for the determination of cell viability, invasion and migration of GC cells.

Results: After neoadjuvant chemotherapy, the expression of miR-27a in serum of GC patients decreased significantly. Additionally, the expression of miR-27a in GC cell line was significantly higher than that in normal gastric mucosa cell line. Meanwhile, after down-regulating the expression of miR-27a in GC cells, the mRNA and protein expression of SFRP1 increased, the proliferation rate of cells slowed down, and the ability of invasion and migration decreased. Furthermore, combined with low expression of miR-27a and SFRP1, the proliferation rate of GC cells increased and the ability of invasion and migration increased.

Conclusion: Collectively, our study highlights that the high expression of miR-27a indicates the poor efficacy and prognosis of neoadjuvant chemotherapy in GC patients. Down-regulation of miR-27a can inhibit the growth and metastasis of GC cells via up-regulation of SFRP1.

Role of microRNAs in osteogenesis of stem cells

Osteogenic differentiation is a controlled developmental process in which external and internal factors including cytokines, growth factors, transcription factors (TFs), signaling pathways and microRNAs (miRNAs) play important roles. Various stimulatory and inhibitory TFs contribute to osteogenic differentiation and are responsible for bone development. In addition, cross-talk between several complex signaling pathways regulates the osteogenic differentiation of some stem cells. Although much is known about regulatory genes and signaling pathways in osteogenesis, the role of miRNAs in osteogenic differentiation still needs to be explored. miRNAs are small, approximately 22 nucleotides, single-stranded nonprotein coding RNAs which are abundant in many mammalian cell types. They paly significant regulated roles in various biological processes and serve as promising biomarkers for disease states. Recently, emerging evidence have shown that miRNAs are the key regulators of osteogenesis of stem cells. They may endogenously regulate osteogenic differentiation of stem cells through direct targeting of positive or negative directors of osteogenesis and depending on the target result in the promotion or inhibition of osteogenic differentiation. This review aims to provide a general overview of miRNAs participating in osteogenic differentiation of stem cells and explain their regulatory effect based on the genes targeted with these miRNAs.

Deregulated miRNAs in bone health: Epigenetic roles in osteoporosis

MicroRNA (miRNA) has shown to enhance or inhibit cell proliferation, differentiation and activity of different cell types in bone tissue. The discovery of miRNA actions and their targets has helped to identify them as novel regulations actors in bone. Various studies have shown that miRNA deregulation mediates the progression of bone-related pathologies, such as osteoporosis. The present review intends to give an exhaustive overview of miRNAs with experimentally validated targets involved in bone homeostasis and highlight their possible role in osteoporosis development. Moreover, the review analyzes miRNAs identified in clinical trials and involved in osteoporosis.

Aberrant expression of microRNAs in peripheral blood mononuclear cells as candidate biomarkers in patients with axial spondyloarthritis

OBJECTIVES

Axial spondyloarthritis (axSpA) is a chronic inflammatory arthritis involving the axial skeleton. Recent evidence suggests that microRNAs (miRNAs) play a critical role in ankylosing spondylitis (AS). In this study, we aimed to investigate whether miR-17-5p, miR-27a, miR-29a and miR-126-3p can be verified as potential biomarkers of axSpA.

METHODS

Peripheral blood mononuclear cell (PBMC) miRNA expression was evaluated by quantitative real-time polymerase chain reaction among 43 patients with AS, 26 patients with non-radiographic axSpA (nr-axSpA) and 39 healthy controls. Detailed clinical histories were recorded and the correlation of miRNAs and clinical features were analyzed.

RESULTS

When compared to controls, both patients with AS and nr-axSpA had significantly higher expression levels of miR-17-5p, miR-27a, miR-29a and miR-126-3p. MiR-27a was negatively correlated with Ankylosing Spondylitis Disease Activity Score as well as C-reactive protein in patients with nr-axSpA (r = -0.51, P < 0.01 and r = -0.42, P = 0.034 respectively). No other clinical features were found to correlate with the four miRNAs in patients with AS. Mir-29a showed highest area under the curve with 0.952 and these four miRNAs may be potential biomarkers in patients with axSpA.

CONCLUSIONS

We reported elevated miR-17-5p, miR-27a, miR-29a and miR-126-3p expression in PBMCs of patients with axSpA, and the expression of these four miRNAs might be used as useful diagnostic markers in axSpA.

Down-regulation of microRNA-31-5p inhibits proliferation and invasion of osteosarcoma cells through Wnt/β-catenin signaling pathway by enhancing AXIN1

OBJECTIVES

Recently, the role of microRNA-31-5p (miR-31-5p) in gene expression regulation has been reported in various cancers. Studies have shown that Wnt/β-catenin signaling pathway is involved in the proliferation and invasion of osteosarcoma (OS) cells. Therefore, this study aims to probe into the regulatory role of miR-31-5p targeting AXIN1 in OS cells through Wnt/β-catenin signaling pathway.

METHODS

Firstly, microarray expression profiles were used to screen differentially expressed miRNAs associated with OS. Next, OS and normal fibrous connective tissues as well as OS cell lines were obtained for investigating the role of miR-31-5p on OS. Then, the putative binding sites between miR-31-5p and AXIN1 were predicted and verified. The regulatory effects of miR-31-5p on proliferation and invasion as well as tumorigenic potential of OS cells targeting AXIN1 were also analyzed. Besides, the relationship between miR-31-5p and Wnt/β-catenin signaling pathway was assessed by immunofluorescence staining.

RESULTS

The microarray dataset GSE63939 showed that miR-31-5p and AXIN1 were involved in OS. miR-31-5p expression increased while the expression of AXIN1 decreased in OS tissues and cells. AXIN1 was identified as a target gene of miR-31-5p, intense expression of which inhibited the transcription of AXIN1. Down-regulated miR-31-5p suppressed proliferation, invasion and tumorigenicity of OS cells through promoting AXIN1. Decreased miR-31-5p activated Wnt/β-catenin signaling pathway, as reflected by increased β-catenin translocation into nuclei, through up-regulating the transcription of AXIN1.

CONCLUSIONS

All in all, repression of miR-31-5p targets AXIN1 to activate the Wnt/β-catenin signaling pathway, thus suppressing proliferation, invasion and tumorigenicity of OS cells.

Retracted: Inhibition of microRNA-940 suppresses the migration and invasion of human osteosarcoma cells through the secreted frizzled-related protein 1-mediated Wnt/β-catenin signaling pathway

Osteosarcoma (OS) is the most common malignant tumor of bone with a high potential for metastasis. This study intends to explore whether microRNA-940 (miR-940) affects the development of OS cells and the underlying mechanism. OS and adjacent normal tissues were collected from OS patients; the OS cell line with the highest expression of miR-940 was selected, which was then subjected to transfection of miR-940 mimic, miR-940 inhibitor, siRNA-secreted frizzled-related protein 1 (SFRP1) or LiCl (agonists of Wnt/β-catenin pathway) to identify regulation of miR-940 to OS cells through SFRP1. The targeting relationship between miR-940 and SFRP1 was verified using dual-luciferase reporter gene assay. Reverse-transcription quantitative polymerase chain reaction and Western blot assay were performed to determine miR-940, SFRP1, β-catenin, and cyclinD1 and apoptosis-related genes Fas, Bax, and Bcl-2. MTT (3-(4, 5-dimethylthiazol-2-Yl)-2, 5-diphenyltetrazolium bromide) assay, scratch test, transwell assay, and flow cytometry were carried out to detect proliferation, migration, invasion, and apoptosis, respectively. Nude mice models were established to observe the tumor formation. Higher expression of miR-940, β-catenin, and cyclinD1 and lower SFRP1 expression were identified in OS tissues. miR-940 targeted and negatively regulated SFRP1 expression. Furthermore, upregulated miR-940 expression activated the Wnt/β-catenin signaling pathway in OS. With the treatment of miR-940 mimic, LiCL, or siRNA-SFRP1, OS cells showed promoted proliferation, migration, invasion, tumor formation, and impeded apoptosis (further reflected by elevated Bcl-2 expression and reduced Fas and Bax expression). The study demonstrates that miR-940 can promote the proliferation, migration, and invasion but suppress the apoptosis of human OS cells by downregulating SFRP1 through activating Wnt/β-catenin signaling pathway.

MiR-27a targets DKK2 and SFRP1 to promote reosseointegration in the regenerative treatment of peri-implantitis

In the inflamed microenvironment of peri-implantitis, limited osteogenesis on the implant surface impedes well-established reosseointegration using current clinical therapies. MicroRNAs (miRNAs) function as potent molecular managers that may simultaneously regulate multiple endogenous processes such as inflammation and osteogenesis. The delivery of miRNAs may provide a way to effectively treat some diseases. In this study, we showed that miR-27a was differentially downregulated in samples from a canine peri-implantitis model. We found that overexpressing miR-27a positively regulated osteogenesis-angiogenesis coupling by ameliorating the TNF-α inhibition of bone formation in vitro. Mechanistically, we identified Dickkopf2 (DKK2) and secreted frizzled related protein 1 (SFRP1) as two essential direct miR-27a targets that were osteogenic and angiogenic. Furthermore, we constructed a miR-27a-enhanced delivery system to repair the bone defect around implants in a canine peri-implantitis model. The results demonstrated that the miR-27a-treated group could optimize new bone formation and reosseointegration in vivo. Our assay provides evidence that this strategy exerts therapeutic effects on peri-implantitis, suggesting that it represents a feasible method to maintain the stability and masticatory function of dental implants. © 2018 American Society for Bone and Mineral Research.

Interplay between microRNAs and Wnt, transforming growth factor-β, and bone morphogenic protein signaling pathways promote osteoblastic differentiation of mesenchymal stem cells

Osteoblasts are terminally differentiated cells with mesenchymal origins, known to possess pivotal roles in sustaining bone microstructure and homeostasis. These cells are implicated in the pathophysiology of various bone disorders, especially osteoporosis. Over the last few decades, strategies to impede bone resorption, principally by bisphosphonates, have been mainstay of treatment of osteoporosis; however, in recent years more attention has been drawn on bone-forming approaches for managing osteoporosis. MicroRNAs (miRNAs) are a broad category of noncoding short sequence RNA fragments that posttranscriptionally regulate the expression of diverse functional and structural genes in a negative manner. An accumulating body of evidence signifies that miRNAs direct mesenchymal stem cells toward osteoblast differentiation and bone formation through bone morphogenic protein, transforming growth factor-β, and Wnt signaling pathways. MiRNAs are regarded as excellent future therapeutic candidates because of their small size and ease of delivery into the cells. Considering their novel therapeutic significance, this review discusses the main miRNAs contributing to the anabolic aspects of bone formation and illustrates their interactions with corresponding signaling pathways involved in osteoblastic differentiation.

[Role of miR-144-3p and its target gene in regulating osteogenic differentiation of rat bone marrow mesenchymal stem cells in vitro]

OBJECTIVE

To investigate the role of miR-144-3p in regulating osteogenic differentiation of bone marrow mesenchymal stem cells and predict its target genes.

METHODS

Rat bone marrow mesenchymal stem cells (BMSCs) with induced osteogenic differentiation were examined for the expressions of Runx2, OCN and miR-144-3p. The effects of transfection with a miR-144-3p mimic or a miR-144-3p inhibitor were tested on the osteogenic differentiation of the BMSCs. The changes in the expressions of the predicted target of miR-144-3p in the BMSCs during induced osteogenic differentiation were examined using Western blotting and qRT-PCR.

RESULTS

Rat BMSCs with induced differentiation into osteoblasts exhibited a progressive increase in the expressions of Runx2 and OCN (two markers of osteogenic differentiation), while the expression of miR-144-3p gradually decreased during the differentiation till reaching the lowest level at 21 days of induction. In rat BMSCs, transfection with the miR-144-3p mimic significantly decreased ALP activity (P < 0.05) wile transfection with the miR-144-3p inhibitor significantly increased ALP activity (P < 0.05) in rat BMSCs. Analysis based on miRanda, microRNA.org database and TargetScan suggested that Smad4 was the most likely target gene of miR-144-3p. The results of qRT-PCR showed no significant differences in expression levels of Smad4 among the cells with different treatments (P > 0.05), while Western blotting revealed a significantly decreased expression of Smad4 in the cells transfected with miR-144-3p mimics and an increased Smad4 expression in the cells transfected with the miR-144-3p inhibitor as compared with the control cells (P < 0.05).

CONCLUSIONS

miR-144-3p participates in the regulation of osteogenic differentiation of rat BMSCs, and its inhibitory effect on osteogenic differentiation is achieved probably by decreasing the expression level of Smad4.

Obesity-associated miR-27a upregulation promotes hepatocellular carcinoma metastasis through suppressing SFRP1

Background

Obesity was a recognized risk factor for the development and progression of hepatocellular carcinoma (HCC). However, the effects and mechanisms by which obesity promotes HCC metastasis remain poorly understood.

Materials and methods

We cultured adipocyte induced by preadipocyte 3T3-L1 in vitro and established HCC metastasis model in obesity mouse in vivo to mimic the tumor microenvironment in obese status. The mechanisms underlying obesity-associated miR-27a upregulation promoting HCC metastasis were investigated.

Results

In this study, we showed that miR-27a was upregulated in adipocytes, obese mouse model and clinical samples, and the increased miR-27a level promoted migration and invasion in HCC cells, increased the number of metastasis nodes in obese mouse model, and was associated with poor clinical outcomes. Overexpressed secreted frizzled-related protein 1 in HCC cells and tissues significantly alleviated the upregulation of β-catenin and matrix metalloproteinase-7 induced by high level of miR-27a. Meanwhile, the E-cadherin expression decreased and Vimentin expression increased, linking with high level of β-catenin in high-fat group.

Conclusion

Taken together, our results have elucidated the critical role of extracellular miR-27a as a pro-metastatic factor in HCC and revealed that obesity-associated miR-27a upregulation promoted HCC metastasis through activated Wnt/β-catenin signaling by suppressing secreted frizzled-related protein 1. Our findings shed light on the novel mechanism underlying HCC metastasis and provided miR-27a as a promising target for obese liver cancer therapy.

Effects of active acromegaly on bone mRNA and microRNA expression patterns

OBJECTIVE

To evaluate the response of bone to chronic long-term growth hormone (GH) and insulin-like growth factor-1 (IGF1) excess by measuring the expression of selected mRNA and microRNA (miR) in bone tissue samples of patients with active acromegaly.

DESIGN

Case-control study.

METHODS

Bone tissue samples were obtained during transsphenoidal adenomectomy from the sphenoid bone (sella turcica) from 14 patients with clinically and biochemically confirmed acromegaly and 10 patients with clinically non-functioning pituitary adenoma (NFPA) matched by sex and age. Expression of genes involved in the regulation of bone remodeling was studied using quantitative polymerase chain reaction (qPCR).

RESULTS

Of the genes involved in osteoblast and osteoclast activity, only alkaline phosphatase (ALP) mRNA was 50% downregulated in patients with acromegaly. GH excess caused increased expression of the Wnt signaling antagonists (DKK1) and agonists (WNT10B) and changes in the levels of miR involved in mesenchymal stem cell commitment to chondrocytes (miR-199a-5p) or adipocytes (miR-27-5p, miR-125b-5p, miR-34a-5p, miR-188-3p) P < 0.05; q < 0.1. Relevant compensatory mechanisms were found through the changes in miR involved in osteoblastogenesis (miR-210-5p, miR-135a-5p, miR-211, miR-23a-3p, miR-204-5p), but the expression of TWIST1 was 50% downregulated and RUNX2 was unchanged.

CONCLUSIONS

Acromegaly had minimal effects on tested mRNAs specific to osteoblast or osteoclast function except for downregulated ALP expression. The expressions of miR known to be involved in mesenchymal stem cell commitment and downregulated TWIST1 expression suggest acromegaly has a negative effect on osteoblastogenesis.

The power of precise bioinformatics prediction of miRNA:mRNA interactions:miR-4699 as a potential inducer of Wnt signaling pathway

microRNAs have attracted interest because of their regulatory effects on gene expression. Experimental detection of potential targets of miRNAs is a laborious task. Considering the expensive techniques of detection, computational approaches for miRNA target prediction can be used as the first step in miRNA research. A large number of tools and algorithms have been developed during the last two decades, led to problems such as confusion in selecting an appropriate tool and false positive or negative results. Therefore, one of the most frequent problems and critical issues of miRNA research is finding a reliable miRNA target prediction tool. In this study, we have proposed a research direction and introduced user-friendly and current databases and tools with the highest accuracy. To verify whether our proposed research direction is practical, we have provided a case example of predicting a miRNA which can target negative regulators of osteogenesis and experimentally evaluated the accuracy of the prediction results by Real-Time PCR and Luciferase assay. The results of RT-qPCR and Luciferase assay indicated a significant decline in expression of Dickkopf-related protein 1 (DKK1) and tumor necrosis factor ligand superfamily member 11 (TNFSF11) as the key negative regulators of osteogenesis upon overexpression of miR-4699-3p. The results emphasize the validity and importance of accurate in silico investigation as the first step in experimental studies. This is the first report detailing the prediction and validation of miR-4699-3p target genes. We suggest hsa-miR-4699 for further investigation as an osteogenic miRNA for therapeutics purposes.

Expression profiling of microRNAs in human bone tissue from postmenopausal women

Bone tissue is composed of several cell types, which express their own microRNAs (miRNAs) that will play a role in cell function. The set of total miRNAs expressed in all cell types configures the specific signature of the bone tissue in one physiological condition. The aim of this study was to explore the miRNA expression profile of bone tissue from postmenopausal women. Tissue was obtained from trabecular bone and was analyzed in fresh conditions (n = 6). Primary osteoblasts were also obtained from trabecular bone (n = 4) and human osteoclasts were obtained from monocyte precursors after in vitro differentiation (n = 5). MicroRNA expression profiling was obtained for each sample by microarray and a global miRNA analysis was performed combining the data acquired in all the microarray experiments. From the 641 miRNAs detected in bone tissue samples, 346 (54%) were present in osteoblasts and/or osteoclasts. The other 46% were not identified in any of the bone cells analyzed. Intersection of osteoblast and osteoclast arrays identified 101 miRNAs shared by both cell types, which accounts for 30-40% of miRNAs detected in these cells. In osteoblasts, 266 miRNAs were detected, of which 243 (91%) were also present in the total bone array, representing 38% of all bone miRNAs. In osteoclasts, 340 miRNAs were detected, of which 196 (58%) were also present in the bone tissue array, representing 31% of all miRNAs detected in total bone. These analyses provide an overview of miRNAs expressed in bone tissue, broadening our knowledge in the microRNA field.

In vivo and in vitro effects of microRNA-27a on proliferation, migration and invasion of breast cancer cells through targeting of SFRP1 gene via Wnt/β-catenin signaling pathway

This study aims to explore the effects of microRNA-27a (miR-27a) targeting of SFRP1 on the proliferation, migration and invasion of breast cancer (BC) cells through the regulation of Wnt/β-catenin signaling pathway. BC and normal breast tissues were obtained from 396 female BC patients and 308 female patients with benign breast lesions respectively. Human normal mammary epithelial (MCF-10A) and BC cell lines (BT-20, MCF-7, T-47D and MDA-MB-231) were cultured. After cell transfection, BC cells were assigned to six groups: control, miR-27a mimics, miR-27a inhibitors, negative control (NC), si-SFRP1 and si-SFRP1 + miR-27a inhibitors groups. qRT-PCR assay and Western blot were employed to detect the expressions of miR-27a, SFRP1, Wnt, β-catenin and GSK3β. MTT assay, wound-healing test and Transwell assay were used to test cell proliferation, migration and invasion. BC tissues were found to have higher miR-27a expression and lower SFRP1 mRNA and protein expressions than MCF-10A cells and normal breast tissues. Compared with the control and NC groups, the miR-27a mimics and si-SFRP1 groups exhibited down-regulation of SFRP1, up-regulation of Wnt, β-catenin and GSK3β, and promotion of cell proliferation, migration and invasion. The miR-27a inhibitor group showed up-regulation of SFRP1 and inhibition of cell proliferation, migration and invasion in comparison to the miR-27a mimic group. The si-SFRP1 + miR-27a inhibitors group also exhibited up-regulation of SFRP1 and inhibition of cell proliferation, migration and invasion in comparison to the si-SFRP1 group. miR-27a may activate the Wnt/β-catenin signaling pathway by negatively regulating SFRP1 to promote the proliferation, migration and invasion of BC cells.

IL-17A Inhibits Osteogenic Differentiation of Bone Mesenchymal Stem Cells via Wnt Signaling Pathway

Background

Interleukin-17A (IL-17A) is not only an important modulator of inflammatory reactions, but also affects bone metabolism, which is involved in osteogenic differentiation of stem cells. However, the role and mechanism of IL-17A in osteogenic differentiation of bone mesenchymal stem cells (BMSCs) are not fully understood. In this study, we investigated the role and mechanism of IL-17A in osteogenic differentiation of BMSCs.

Material/Methods

The osteogenic differentiation of BMSCs was induced by osteoblast-induction medium with IL-17A or without IL-17A. The osteogenic differentiation of BMSCs was confirmed by the alkaline phosphatase and alizarin red staining. The lentiviral plasmid was used to construct the sFRP1-shRNA expression vector. The associated osteogenic differentiation marks (RUNX2, ALP, OPN), Wnt signaling pathway inhibitor (sFRP1), and modulators of Wnt signaling pathway (Wnt3, Wnt6) were detected by qRT-PCR and Western blot method.

Results

The results showed that the addition of IL-17A inhibited osteogenic differentiation of BMSCs. IL-17A induced up-regulated expression of sFRP1 and down-regulated expression of Wnt3 and Wnt6 in BMSCs. In addition, sFRP1-shRNA abolished the inhibition effect of IL-17A in osteogenic differentiation of BMSCs and induced up-regulated expression of Wnt3 and Wnt6 in the Wnt signaling pathway in BMSCs.

Conclusions

Our findings show that IL-17A inhibits osteogenic differentiation of bone mesenchymal stem cells via the Wnt signaling pathway.

Transcriptional suppression of microRNA-27a contributes to laryngeal cancer differentiation via GSK-3β-involved Wnt/β-catenin pathway

miR-27a regulates cell differentiation in a variety of diseases. However, whether and how miR-27a participates in laryngeal cancer cell differentiation remains unknown. Therefore, we explored role and molecular mechanism of miR-27a in laryngeal cancer differentiation in the study. We found that miR-27a expression was inversely correlated with laryngeal cancer differentiation degree based on the clinical pathological diagnosis of each patient. miR-27 asignificantly rescued differentiation and inhibited β-catenin, LEF1, OCT4 and SOX2 in Wnt/β-catenin pathway in all-trans-retinoic acid (ATRA)-induced laryngeal cancer cells. Bindings of RARα to miR-27a and miR-27a to GSK-3β were confirmed by ChIP and Luciferase reporter assays, respectively. In conclusion, miR-27a is a negative regulator in laryngeal cancer differentiation. RARα-mediated miR-27a transcriptional inactivation releases the inhibition of miR-27a on GSK-3β leading to laryngeal cancer differentiation through GSK-3β-involved Wnt/β-catenin pathway, suggesting that miR-27a is a usefully therapeutic target at least in ATRA-induced laryngeal cancer differentiation.

MicroRNA-542-3p inhibits oral squamous cell carcinoma progression by inhibiting ILK/TGF-β1/Smad2/3 signaling

In this study, we investigated the effects of microRNA-542-3p (miR-542-3p) on ILK/TGF-β1/Smad2/3 signaling and oral squamous cell carcinoma (OSCC) progression. Levels of miR-542-3p were lower in OSCC tissues (n=108) than adjacent normal tissues, whereas levels of ILK, TGF-β1 and Smad2/3 were higher. Patients with undifferentiated tumors, advanced TNM stage and lymph node metastasis showed low miR-542-3p levels. This was accompanied by high ILK expression and poor survival. Dual luciferase reporter assays of SCC-9 cells showed that miR-542-3p inhibited ILK gene expression by binding to its 3’UTR at 233-240 bp. SCC-9 cells transfected with miR-542-3p mimics exhibited elevated miR-542-3p and decreased ILK, TGF-β1 and Smad2/3 expression. They also showed reduced self-renewal (fewer CD44⁺ cells and tumor-spheres), invasiveness, migration, proliferation and survival. Conversely, miR-542-3p inhibitors promoted increased self-renewal (more CD44⁺ cells and tumor-spheres), invasiveness, migration, proliferation and survival. In xenograft experiments with nude mice, SCC-9 cells transfected with miR-542-3p mimics or siRNA-ILK yielded tumors with smaller volumes and weights than control tumors. These results demonstrate that miR-542-3p is a tumor suppressor that inhibits ILK/TGF-β1/Smad2/3 signaling, thereby inhibiting OSCC progression.

MicroRNA expression analysis during FK506-induced osteogenic differentiation in rat bone marrow stromal cells

FK506 (also known as tacrolimus) is a potent immunosuppressive agent that is widely used in the treatment of graft-rejection and autoimmune diseases. FK506 has attracted additional attention owing to its potential role in osteogenic differentiation and bone formation. MicroRNAs (miRNAs) have been demonstrated to serve important roles in the regulation of osteogenic differentiation; however, identification of specific miRNAs and their roles in regulating FK506-induced osteogenic differentiation have been poorly examined. In the present study, osteodifferentiation of rat bone marrow stromal cells (BMSCs) was induced with varying concentrations of FK506 (5–5,000 nM) for 3, 7 and 14 days. Differentially expressed miRNAs were profiled using miRNA array, verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and subjected to gene ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Results from the present study identified a subset of miRNAs that were differentially expressed, of which five upregulated miRNAs (miR-106b-5p, miR-101b-3p, miR-193a-3p, miR-485-3p and miR-142-3p) and four downregulated miRNAs (miR-27a-3p, miR-207, miR-218a-2-3p and let-7a-5p) were confirmed by RT-qPCR. GO and KEGG analysis revealed that the predicted target genes of these miRNAs are involved in multiple biological processes and signaling pathways, including cell differentiation and the mitogen-activated protein kinase (MAPK) signaling pathway. Verification of the miRNA-target genes revealed that Smad5, Jagged 1 and MAPK9 were significantly upregulated, whereas Smad7, BMP and activin membrane-bound inhibitor, and dual-specificity phosphatase 2 were significantly downregulated during FK506-induced osteodifferentiation. The present study may provide an experimental basis for further research on miRNA functions during FK506-induced osteogenic differentiation in rat BMSCs.

MicroRNA-27a-3p Modulates the Wnt/β-Catenin Signaling Pathway to Promote Epithelial-Mesenchymal Transition in Oral Squamous Carcinoma Stem Cells by Targeting SFRP1

This study aimed to elucidate how microRNA27a-3p (miR-27a-3p) modulates the Wnt/β-catenin signaling pathway to promote the epithelial-mesenchymal transition (EMT) in oral squamous carcinoma stem cells (OSCSCs) by targeting secreted frizzled-related protein 1 (SFRP1). Flow cytometry was used to sort OSCSCs from the SCC-9 and Tca8113 cell lines. The OSCSCs were randomly assigned into the miR-27a-3p inhibitors group, the miR-27a-3p inhibitors-NC group, the si-SFRP1 group, the si-SFRP1 + miR-27a-3p inhibitors group and the blank group. A luciferase reporter, immunofluorescence and Transwell assays were performed to detect luciferase activity, SFRP1, and cell migration and invasion, respectively. The mRNA expression of miR-27a-3p, SFRP1 and EMT markers (E-cadherin, N-cadherin, vimentin and ZEB1) were detected using qRT-PCR. The protein expression of SFRP1, EMT markers and the proteins of the Wnt/β-catenin signaling pathway was detected by Western blotting. OSCSCs showed up-regulated miR-27a-3p, Wnt/β-catenin signaling pathway-related proteins, vimentin, N-cadherin and ZEB1 and down-regulated SFRP1 and E-cadherin. MiR-27a-3p targeted SFRP1. Down-regulated miR-27a-3p resulted in increased E-cadherin and SFRP1 but decreased vimentin, N-cadherin, ZEB1, the Wnt/β-catenin signaling pathway-related proteins, and invasive and migratory cells. Silenced SFRP1 reversed this effect. We found that miR-27a-3p modulated the Wnt/β-catenin signaling pathway to promote EMT in OSCSCs by down-regulating SFRP1.

Dysregulated miR-27a-3p promotes nasopharyngeal carcinoma cell proliferation and migration by targeting Mapk10

miRNA-27a-3p is an important regulator of carcinogenesis and other pathological processes. However, its role in laryngeal carcinoma is still unknown. In our previous research, we found that miR-27a-3p expression was upregulated in nasopharyngeal carcinoma (NPC) using a microarray chip. In the present study, we identified miR-27a-3p as an endogenous promoter of metastatic invasion. The expression levels of miR-27a-3p were correlated with human metastatic progression outcomes and Kaplan-Meier survival. In silico database analyses revealed that Mapk10 is a potential target of miR-27a-3p, and luciferase reporter assay results revealed that miR-27a-3p directly inhibits the Mapk10 3 untranslated region (3′UTR). Real-time PCR and western blotting results ascertained that Mapk10 expression was regulated by miR-27a-3p. In addition, miR-27a-3p gain-of-function promoted cell proliferation, migration and invasion in 5–8 F NPC cells. These effects partially depended on Mapk10, and loss of miR-27a-3p function had the opposite effects.

Genetic variants in the 3' untranslated region of sFRP1 gene and risk of gastric cancer in a Chinese population

BACKGROUND

Secreted frizzled-related protein 1 (sFRP1), a negative regulator of the Wnt signaling pathway, is frequently inactivated in human gastric cancer. Genetic variants in the 3' untranslated region (UTR) of the gene may influence the strength of miRNA binding and the regulation of mRNA transcription, affecting the individual's cancer risk. This study aims to investigate the impact of variants in the 3' UTR of sFRP1 on the gastric cancer susceptibility in a Chinese population.

PATIENTS AND METHODS

The association between 2 sFRP1 gene variation loci (rs1127379 and rs10088390) with minor allele frequency more than 0.1 in the 3' UTR and gastric cancer risk was assessed in a case-control study including 419 gastric cancer cases and 571 healthy controls. PCR-restriction fragment length polymorphism analysis was used for genotyping; the odds ratio and 95% confidence interval were calculated to estimate the relative risk.

RESULTS

Compared with the AA genotype, the GG genotype of rs1127379 was significantly associated with a reduced risk of gastric cancer overall. In the subgroup analysis, the protective effect of the GG genotype was also found for noncardia cancer and intestinal gastric cancer. Furthermore, haplotype analysis showed that the A rs1127379 G rs10088390 haplotype conferred a risk effect for gastric cancer.

CONCLUSIONS

Genetic variants at the sFRP1 gene may be involved in gastric tumorigenesis, especially in noncardia and intestinal gastric cancer. Further prospective studies with different ethnicities and large sample sizes are needed to confirm our findings.

MiRNA-27a promotes the proliferation and invasion of human gastric cancer MGC803 cells by targeting SFRP1 via Wnt/β-catenin signaling pathway

This study aims to elucidate the effects of microRNA-27a (miR-27a) on the proliferation and invasion of gastric cancer (GC) cells by targeting SFRP1 via Wnt/β-catenin signaling pathway. GC and normal adjacent tissues were collected from 273 GC patients. Human gastric cancer cell line (MGC803) and normal human gastric mucosal cell line (GES-1) were cultured. The miR-27a mRNA expression was analyzed using Quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemistry (IHC) test was used to detect miR-27a and SFRP1 protein expressions. After transfection, cells were divided into five groups: the negative control (NC) group, the miR-27a inhibitor group, the miR-27a mimics group, the miR-27a inhibitor + SFRP1 siRNA group and the miR-27a mimics + SFRP1 overexpression group. Western blotting was conducted to test SFRP1 and Wnt/β-catenin protein expression. Analysis for the target gene of miR-27a was performed using Luciferase assay. Cell proliferation, migration and invasion were determined by CCK8 and Transwell assay. The dual-luciferase reporter assay system was applied to analyze the effects of miR-27a on Wnt/β-catenin signaling pathway. In GC tissue and cell line, miR-27a protein and mRNA expressions were up-regulated, and SFRP1 protein and mRNA expressions were down-regulated. Luciferase assay indicated that miR-27a might target SFRP1 and regulate its expressions. When miR-27a was down-regulated, SFRP1 was up-regulated, and β-catenin, Wnt, p-β-catenin, and p-Wnt were significantly down-regulated. Compared with the NC group, the proliferation, migration and invasion of GC cells were remarkably increased in the miR-27a group, but these were declined in the miR-27a mimics + SFRP1 overexpression group. The proliferation, migration and invasion of GC cells were elevated in the miR-27a inhibitor + SFRP1 siRNA group compared with the miR-27a inhibitor group. These results showed that miR-27a was highly expressed in GC tissues and cells, and it might promote cell proliferation, migration and invasion by targeting SFRP1 via the activation of Wnt/β-catenin signaling pathway.

MicroRNAs in bone development and their diagnostic and therapeutic potentials in osteoporosis

MicroRNAs (miRNAs) are small non-coding RNAs approximately 22 nucleotides in length. miRNAs play an important role in the posttranscriptional regulation of gene expression via translational repression and targeting messenger RNA for degradation. In vivo and in vitro evidence has established the importance of miRNAs in physiology and developmental processes such as cell proliferation, differentiation, survival and apoptosis. miRNA dysregulation is associated with the pathogenesis of cardiovascular diseases, metabolic syndromes, and degenerative diseases. An increasing number of miRNAs have been found to play an important role in bone homeostasis. In this review, the roles of miRNAs in the regulation of bone formation and resorption as well as miRNAs that regulate key transcription factors of osteogenesis are discussed. A special emphasis is given to miRNAs whose direct targets have been identified. The miRNAs that contribute to the pathogenesis of osteoporosis and their therapeutic potential are also considered.

miR-27a attenuates adipogenesis and promotes osteogenesis in steroid-induced rat BMSCs by targeting PPARγ and GREM1

The imbalance between adipogenic and osteogenic differentiation in bone marrow mesenchymal stem cells (BMSCs) plays a significant role in the pathogenesis of steroid-induced osteonecrosis of the femoral head (ONFH). Several microRNAs (miRNAs) are involved in regulating adipogenesis and osteogenesis. In this study, we established a steroid-induced ONFH rat model to identify the potential relevant miRNAs. We identified 9 up-regulated and 28 down-regulated miRNAs in the ONFH rat model. Of these, miR-27a was down-regulated and negatively correlated with peroxisome proliferator-activated receptor gamma (PPARγ) and gremlin 1 (GREM1) expression. Further studies confirmed that PPARγ and GREM1 were direct targets of miRNA-27a. Additionally, adipogenic differentiation was enhanced by miR-27a down-regulation, whereas miRNA-27a up-regulation attenuated adipogenesis and promoted osteogenesis in steroid-induced rat BMSCs. Moreover, miRNA-27a up-regulation had a stronger effect on adipogenic and osteogenic differentiation in steroid-induced rat BMSCs than si-PPARγ and si-GREM1. In conclusion, we identified 37 differentially expressed miRNAs in the steroid-induced ONFH model, of which miR-27a was down-regulated. Our results showed that miR-27a up-regulation could inhibit adipogenesis and promote osteogenesis by directly targeting PPARγ and GREM1. Thus, miR-27a is likely a key regulator of adipogenesis in steroid-induced BMSCs and a potential therapeutic target for ONFH treatment.