MicroRNA-361-3p regulates retinoblastoma cell proliferation and stemness by targeting hedgehog signaling

Hedgehog signaling in tissue homeostasis, cancers, and targeted therapies

The past decade has seen significant advances in our understanding of Hedgehog (HH) signaling pathway in various biological events. HH signaling pathway exerts its biological effects through a complex signaling cascade involved with primary cilium. HH signaling pathway has important functions in embryonic development and tissue homeostasis. It plays a central role in the regulation of the proliferation and differentiation of adult stem cells. Importantly, it has become increasingly clear that HH signaling pathway is associated with increased cancer prevalence, malignant progression, poor prognosis and even increased mortality. Understanding the integrative nature of HH signaling pathway has opened up the potential for new therapeutic targets for cancer. A variety of drugs have been developed, including small molecule inhibitors, natural compounds, and long non-coding RNA (LncRNA), some of which are approved for clinical use. This review outlines recent discoveries of HH signaling in tissue homeostasis and cancer and discusses how these advances are paving the way for the development of new biologically based therapies for cancer. Furthermore, we address status quo and limitations of targeted therapies of HH signaling pathway. Insights from this review will help readers understand the function of HH signaling in homeostasis and cancer, as well as opportunities and challenges of therapeutic targets for cancer.

The functional role of circular RNAs in the pathogenesis of retinoblastoma: a new potential biomarker and therapeutic target?

Retinoblastoma (RB) is a common cancer in infants and children. It is a curable disease; however, a delayed diagnosis or treatment makes the treatment difficult. Genetic mutations have a central role in the pathogenesis of RB. Genetic materials such as RNAs (coding and non-coding RNAs) are also involved in the progression of the tumor. Circular RNA (circRNA) is the most recently identified RNA and is involved in regulating gene expression mainly through "microRNA sponges". The dysregulation of circRNAs has been observed in several diseases and tumors. Also, various studies have shown that circRNAs expression is changed in RB tissues. Due to their role in the pathogenesis of the disease, circRNAs might be helpful as a diagnostic or prognostic biomarker in patients with RB. In addition, circRNAs could be a suitable therapeutic target to treat RB in a targeted therapy approach.

The role of Hedgehog and Notch signaling pathway in cancer

Notch and Hedgehog signaling are involved in cancer biology and pathology, including the maintenance of tumor cell proliferation, cancer stem-like cells, and the tumor microenvironment. Given the complexity of Notch signaling in tumors, its role as both a tumor promoter and suppressor, and the crosstalk between pathways, the goal of developing clinically safe, effective, tumor-specific Notch-targeted drugs has remained intractable. Drugs developed against the Hedgehog signaling pathway have affirmed definitive therapeutic effects in basal cell carcinoma; however, in some contexts, the challenges of tumor resistance and recurrence leap to the forefront. The efficacy is very limited for other tumor types. In recent years, we have witnessed an exponential increase in the investigation and recognition of the critical roles of the Notch and Hedgehog signaling pathways in cancers, and the crosstalk between these pathways has vast space and value to explore. A series of clinical trials targeting signaling have been launched continually. In this review, we introduce current advances in the understanding of Notch and Hedgehog signaling and the crosstalk between pathways in specific tumor cell populations and microenvironments. Moreover, we also discuss the potential of targeting Notch and Hedgehog for cancer therapy, intending to promote the leap from bench to bedside.

Role of lncRNA MIAT/miR-361-3p/CCAR2 in prostate cancer cells

The study was aimed to investigate the role and mechanism of long non-coding RNAs (lncRNA) myocardial infarction-associated transcript (MIAT) in prostate cancer. The relationships between lncRNA MIAT and miR-361-3p, miR-361-3p and cell cycle and apoptosis regulator 2 (CCAR2) were predicted by StarBase and TargetScan, and verified by dual-luciferase reporter assay and RNA pull-down assay. Quantitative real-time PCR assay was performed to detect the mRNA expression of lncRNA MIAT, miR-361-3p, CCAR2, Bax, and Bcl-2 in the prostate cancer tissues or cells. The protein levels of CCAR2, Bax, and Bcl-2 were detected by Western blot analysis. The cell viability and apoptosis were detected by MTT assay and Flow cytometry analysis, respectively. lncRNA MIAT was upregulated, while miR-361 was downregulated in the prostate cancer tissues and Du145 cells. lncRNA MIAT negatively regulated miR-361-3p expression in Du145 cells. Downregulating lncRNA MIAT decreased the cell viability, induced the cell apoptosis, increased Bax expression, and decreased Bcl-2 expression in Du145 cells, while the effects were reversed by downregulating miR-361-3p or CCAR2 upregulation. Moreover, CCAR2 upregulation reversed the effects of miR-361-3p upregulation on Du145 cell viability and apoptosis. In conclusion, lncRNA MIAT participated in prostate cancer by regulating cell proliferation and apoptosis via miR-361-3p/CCAR2 axis.

Emerging role of non-coding RNAs in the regulation of Sonic Hedgehog signaling pathway

Sonic Hedgehog (Shh) signaling cascade is one of the complex signaling pathways that control the accurately organized developmental processes in multicellular organisms. This pathway has fundamental roles in the tumor formation and induction of resistance to conventional therapies. Numerous non-coding RNAs (ncRNAs) have been found to interact with Shh pathway to induce several pathogenic processes, including malignant and non-malignant disorders. Many of the Shh-interacting ncRNAs are oncogenes whose expressions have been increased in diverse malignancies. A number of Shh-targeting miRNAs such as miR-26a, miR-1471, miR-129-5p, miR-361-3p, miR-26b-5p and miR-361-3p have been found to be down-regulated in tumor tissues. In addition to malignant conditions, Shh-interacting ncRNAs can affect tissue regeneration and development of neurodegenerative disorders. XIST, LOC101930370, lncRNA-Hh, circBCBM1, SNHG6, LINC‐PINT, TUG1 and LINC01426 are among long non-coding RNAs/circular RNAs that interact with Shh pathway. Moreover, miR-424, miR-26a, miR-1471, miR-125a, miR-210, miR-130a-5p, miR-199b, miR-155, let-7, miR-30c, miR-326, miR-26b-5p, miR-9, miR-132, miR-146a and miR-425-5p are among Shh-interacting miRNAs. The current review summarizes the interactions between ncRNAs and Shh in these contexts.

Integrated analysis of multiple bioinformatics studies to identify microRNA-target gene-transcription factor regulatory networks in retinoblastoma

Background

In children, retinoblastoma (RB) is one of the most common primary malignant ocular tumors and has a poor prognosis and high mortality. To understand the molecular mechanisms of RB, we identified microRNAs (miRNAs), key genes and transcription factors (TFs) using bioinformatics analysis to build potential miRNA-gene-TF networks.

Methods

We collected three gene expression profiles and one miRNA expression profile from the Gene Expression Omnibus (GEO) database. We used the limma R package to identify overlapping differentially expressed genes (DEGs) and differentially expressed miRNAs in RB tissues compared to noncancer tissues. The robust rank aggregation (RRA) method was implemented to identify key genes among the DEGs. Then, miRNA-key gene-TF networks were built using the online tools TransmiR and miRTarBase. Next, we used RT-qPCR to confirm the results.

Results

We identified 180 DEGs in RB tissues compared to nontumor tissues using integrative analysis, among which 109 genes were upregulated and 71 were downregulated. Gene ontology (GO) analysis revealed that these DEGs were primarily involved with chromosome segregation, condensed chromosome and DNA replication origin binding. The most highly enriched pathways obtained in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were cell cycle, DNA replication, homologous recombination, P53 signaling pathway and pyrimidine metabolism. Furthermore, two key differentially expressed miRNAs (DEMs) were also established: let-7a and let-7b. Finally, the potential regulatory networks of miRNA-target gene-TFs were examined.

Conclusions

This study identified key genes and built miRNA-target gene-TF regulatory networks in RB, which will deepen our understanding of the molecular mechanisms involved in the development of RB. These key genes and miRNAs may be potential targets and biomarkers for RB diagnosis and therapy.

The crosstalk between long non-coding RNAs and the hedgehog signaling pathway in cancer

Hedgehog (Hh) is a conserved signaling pathway that is involved in embryo development as well as adult tissue maintenance and repair in invertebrates and vertebrates. Abnormal activation of this pathway in various types of malignant drug- and apoptosis-resistant tumors has made it a therapeutic target against tumorigenesis. Thus, understanding the molecular mechanisms that promote the activation or inhibition of this pathway is critical. Long non-coding RNAs (lncRNAs), a subclass of non-coding RNAs with a length of > 200 nt, affect the expression of Hh signaling components via a variety of transcriptional and post-transcriptional processes. This review focuses on the crosstalk between lncRNAs and the Hh pathway in carcinogenesis, outlines the broad role of Hh-related lncRNAs in tumor progression, and illustrates their clinical diagnostic, prognostic, and therapeutic potential in tumors.

Noncoding RNAs related to the hedgehog pathway in cancer: clinical implications and future perspectives

Cancer is a type of malignant affliction threatening human health worldwide; however, the molecular mechanism of cancer pathogenesis remains to be elusive. The oncogenic hedgehog (Hh) pathway is a highly evolutionarily conserved signaling pathway in which the hedgehog-Patched complex is internalized to cellular lysosomes for degradation, resulting in the release of Smoothened inhibition and producing downstream intracellular signals. Noncoding RNAs (ncRNAs) with diversified regulatory functions have the potency of controlling cellular processes. Compelling evidence reveals that Hh pathway, ncRNAs, or their crosstalk play complicated roles in the initiation, metastasis, apoptosis and drug resistance of cancer, allowing ncRNAs related to the Hh pathway to serve as clinical biomarkers for targeted cancer therapy. In this review, we attempt to depict the multiple patterns of ncRNAs in the progression of malignant tumors via interactions with the Hh crucial elements in order to better understand the complex regulatory mechanism, and focus on Hh associated ncRNA therapeutics aimed at boosting their application in the clinical setting.

Applications of Non-Coding RNAs in Patients With Retinoblastoma

Retinoblastoma (RB) is the most common primary intraocular malignancy in childhood. In the carcinogenic process of neoplasms such as RB, the role of non-coding RNAs (ncRNAs) has been widely demonstrated recently. In this review, we aim to provide a clinical overview of the current knowledge regarding ncRNAs in relation to RB. Although ncRNAs are now considered as potential diagnostic biomarkers, prognostic factors, and therapeutic targets, further studies will facilitate enhanced understanding of ncRNAs in RB physiopathology and define the roles ncRNAs can play in clinical practice.

The Role of the SOX9/lncRNA ANXA2P2/miR-361-3p/SOX9 Regulatory Loop in Cervical Cancer Cell Growth and Resistance to Cisplatin

Cervical cancer is a highly prevalent female malignancy. Presently, cisplatin (DDP) is a first-line agent for cervical cancer chemotherapy. However, its curative effect is limited because of chemo-resistance. It has been previously reported that SOX9 targeted and activated oncogenic genes, enhancing cervical cancer cell resistance to DDP. The effects of the SOX9/lncRNA ANXA2P2/miR-361-3p/SOX9 regulatory loop on cervical cancer cell growth and resistance to DDP have been demonstrated. miR-361-3p expression was decreased in DDP-resistant cervical cancer cells and tissues. Moreover, miR-361-3p overexpression inhibited the growth of resistant cervical cancer cells and the resistance to DDP, whereas miR-361-3p inhibition exerted opposite effects. miR-361-3p inhibited SOX9 expression through binding; the effects of miR-361-3p inhibition were partially reversed by SOX9 knockdown. LncRNA ANXA2P2 expression was elevated in DDP-resistant cervical cancer cells and tissues. LncRNA ANXA2P2 inhibited miR-361-3p expression by binding, thereby upregulating SOX9. LncRNA ANXA2P2 knockdown inhibited DDP-resistant cervical cancer cell growth and resistance to DDP, whereas the effects of lncRNA ANXA2P2 knockdown were partially reversed by miR-361-3p inhibition. SOX9 expression was elevated in DDP-resistant cervical cancer cells and tissues, and SOX9 activated lncRNA ANXA2P2 transcription by binding. Collectively, SOX9, lncRNA ANXA2P2, and miR-361-3p form a regulatory loop, modulating DDP-resistant cervical cancer cell growth and response to DDP treatment.

MicroRNA-361 reduces the viability and migratory ability of pancreatic cancer cells via mediation of the MAPK/JNK pathway

Previous research has revealed that microRNA-361 (miR-361) functions as a fundamental modulator in non-small-cell lung cancer and esophageal carcinoma. However, its involvement in pancreatic cancer (PC) is yet to be elucidated. Therefore, the present study aimed to examine the mechanism and function of miR-361 during the regulation of PC cell migration and viability. It was demonstrated that miR-361 expression decreased in PC cell lines and tissues, and the overexpression of miR-361 suppressed in vivo PC cell proliferation in mice. Moreover, flow cytometry and MTT assays indicated that the miR-361 mimic decreased the viability and increased the apoptosis of PC cells. Both Transwell migration and wound healing assays identified that miR-361 ameliorated the migratory ability of PC cells. Using dual-luciferase reporter assays, it was found that miR-361 targeted mitogen-activated protein kinase (MAPK)/JNK 3'-untranslated regions, inducing the downregulation of this gene. In PC cells, overexpression of MAPK/JNK diminished the pro-apoptotic effect of the miR-361 mimic, while restoring the migratory activity of PC cells. Collectively, the present results suggested novel molecular mechanisms underlying PC progression and development.

Therapeutic effects of mesenchymal stem cells-derived extracellular vesicles' miRNAs on retinal regeneration: a review

Extracellular vesicles (EVs), which consist of microvesicles and exosomes, are secreted from all cells to transform vital information in the form of lipids, proteins, mRNAs and small RNAs such as microRNAs (miRNAs). Many studies demonstrated that EVs' miRNAs have effects on target cells. Numerous people suffer from the blindness caused by retinal degenerations. The death of retinal neurons is irreversible and creates permanent damage to the retina. In the absence of acceptable cures for retinal degenerative diseases, stem cells and their paracrine agents including EVs have become a promising therapeutic approach. Several studies showed that the therapeutic effects of stem cells are due to the miRNAs of their EVs. Considering the effects of microRNAs in retinal cells development and function and studies which provide the possible roles of mesenchymal stem cells-derived EVs miRNA content on retinal diseases, we focused on the similarities between these two groups of miRNAs that could be helpful for promoting new therapeutic techniques for retinal degenerative diseases.

Circular RNA SERPINE2 promotes development of glioblastoma by regulating the miR-361-3p/miR-324-5p/BCL2 signaling pathway

Circular RNA (circRNA) is a new type of long-sequence RNA formed by a noncanonical form of alternative splicing called back-splicing. Emerging evidence has revealed that circRNAs are involved in cancer progression, regulating cancer-related genes through sponging microRNAs (miRNAs). In our study, we identified a novel upregulated circRNA, circSERPINE2, through analyzing circRNAs microarray data of glioblastoma from GEO datasets (GSE146463). Quantitative real-time PCR was used to further confirm the upregulation of circSERPINE2 in glioblastoma cell lines and tissues. Silencing circSERPINE2 inhibits glioblastoma proliferation in vivo and in vitro through cell counting kit-8 (CCK-8) assay, colony formation assay, flow cytometry analysis, and western blot analysis and xenograft tumor model. Mechanistically, circSERPINE2 could directly sponge miR-324-5p and miR-361-3p. BCL2, known as a novel anti-apoptosis gene, is a target gene both of miR-324-5p and miR-361-3p. Thus, circSERPINE2 promotes BCL2 expression through sponging miR-324-5p and miR-361-3p. In conclusion, our study revealed the biological function and mechanism of circSERPINE2 in glioblastoma progression and that circSERPINE2 could be a potential therapeutic target for glioblastoma.

Targeting non-coding RNAs for the treatment of retinal diseases

Maintaining visual function is key to establishing improved longevity. However, the numbers of patients with diseases of the retina, the most important tissue for vision and the key to age-related blindness, are not declining due to the increase in the number of aging subjects worldwide and the technological advances in the delivery of premature infants. The primary treatment option for retinal diseases is still surgical intervention and includes laser or photocoagulation, which are associated with various complications and side effects. Many aspects of the pathogenesis of these retinal diseases are still unknown, thereby impeding drug discovery. This has led to an increase in the number of studies focused on the underlying pathogenic mechanisms of retinal diseases. Growing evidence suggests that non-coding RNAs play critical roles in the pathogenesis of retinal diseases. Herein, we have summarized the known functional roles of non-coding RNAs, emphasizing their contribution to the underlying pathogenesis of retinal diseases. In addition, we discuss the modulation of non-coding RNAs as potential therapeutics and the methods to control the non-coding RNAs for the treatment. We expect that targeting non-coding RNAs could be crucial for developing novel therapeutics for progressive diseases including diseases of the retina.

The Effect of miR-361-3p Targeting TRAF6 on Apoptosis of Multiple Myeloma Cells

microRNA-361-3p (miR-361-3p) is involved in the carcinogenesis of oral cancer and pancreatic catheter adenocarcinoma, and has anti-carcinogenic effects on non-small cell lung cancer (NSCLC). However, its effect on multiple myeloma (MM) is less reported. Here, we found that upregulating the expression of miR-361-3p inhibited MM cell viability and promoted MM apoptosis. We measured expressions of tumor necrosis factor receptor-associated factor 6 (TRAF6) and miR-361-3p in MM cells and detected the viability, colony formation rate, and apoptosis of MM cells. In addition, we measured expressions of apoptosis-related genes Bcl-2, Bax, and Cleaved caspase-3 (C caspase-3). The binding site between miR-361-3p and TRAF6 was predicted by TargetScan. Our results showed that miR-361-3p was low expressed in the plasma of MM patients and cell lines, while its overexpression inhibited viability and colony formation of MM cells and increased the cell apoptosis. Furthermore, TRAF6, which was predicted to be a target gene of miR-361-3p, was highexpressed in the plasma of patients and cell lines with MM. Rescue experiments demonstrated that the effect of TRAF6 on MM cells was opposite to that of miR-361-3p. Upregulation of miR-361-3p induced apoptosis and inhibited the proliferation of MM cells through targeting TRAF6, suggesting that miR-361-3p might be a potential target for MM therapy.

Regulation of breast cancer metastasis signaling by miRNAs

Despite the decline in death rate from breast cancer and recent advances in targeted therapies and combinations for the treatment of metastatic disease, metastatic breast cancer remains the second leading cause of cancer-associated death in U.S. women. The invasion-metastasis cascade involves a number of steps and multitudes of proteins and signaling molecules. The pathways include invasion, intravasation, circulation, extravasation, infiltration into a distant site to form a metastatic niche, and micrometastasis formation in a new environment. Each of these processes is regulated by changes in gene expression. Noncoding RNAs including microRNAs (miRNAs) are involved in breast cancer tumorigenesis, progression, and metastasis by post-transcriptional regulation of target gene expression. miRNAs can stimulate oncogenesis (oncomiRs), inhibit tumor growth (tumor suppressors or miRsupps), and regulate gene targets in metastasis (metastamiRs). The goal of this review is to summarize some of the key miRNAs that regulate genes and pathways involved in metastatic breast cancer with an emphasis on estrogen receptor α (ERα+) breast cancer. We reviewed the identity, regulation, human breast tumor expression, and reported prognostic significance of miRNAs that have been documented to directly target key genes in pathways, including epithelial-to-mesenchymal transition (EMT) contributing to the metastatic cascade. We critically evaluated the evidence for metastamiRs and their targets and miRNA regulation of metastasis suppressor genes in breast cancer progression and metastasis. It is clear that our understanding of miRNA regulation of targets in metastasis is incomplete.

MicroRNA-34b-5p inhibits proliferation, stemness, migration and invasion of retinoblastoma cells via Notch signaling

Retinoblastoma (RB) is one of the most common forms of childhood intraocular cancer. While the occurrence of RB is traditionally associated with dysregulation of the RB1 gene, efforts have been made to assess the role of several other pathways that may result in RB. The Notch signaling pathway has been identified as one of the sentinel pathways in retinal development and has been indicated to serve as a tumor suppressor. However, epigenetic modifications of the Notch signaling pathway, and their consequences on tumor establishment and progression, have received little attention. The present study attempted to elucidate the microRNA (miR)-mediated dysregulation of the Notch signaling pathway and its implications on tumor initiation. Upon recruitment of patients with RB (age, 4-25 months), the levels of miR-34b-5p were determined in tumor and adjacent healthy tissues. Simultaneously, the serum levels of miR-34b-5p were measured in tumor and healthy samples using reverse transcriptase-quantitative PCR (RT-qPCR). Binding of miR-34b-5p to Notch1 and Notch2 were confirmed bioinformatically. In vitro studies were performed in Y79 and Weri-Rb-1 RB cell lines. The cell lines were transfected with miR-34b-5p constructs and miR-34b-5p overexpression was confirmed using RT-qPCR. The impact of miR-34b-5p overexpression on cell growth and cancer stemness markers (Sox-2, Nanog, and CD133) was examined. The expression levels of Notch1 and Notch2 were evaluated in the presence of miR-34b-5p. The rescue of cell growth and cancer stemness phenotypes was evaluated by co-transfection of miR-34b-5p with Notch1 or Notch2. The results of the present study indicated that the expression levels of miR-34b-5p were reduced in patient tissues and serum samples compared with those in healthy tissues and samples. Notch1 and Notch2 expression level was negatively correlated with the expression level of miR-34b-5p. Overexpression of miR-34b-5p resulted in reduced cell proliferation, migration, invasion and cancer stemness compared with the control group. Further in vivo experiments confirmed the inhibitory effects of miR-34b-5p on RB cell proliferation. Upon co-transfection of miR-34b-5p with Notch1 or Notch2, these phenotypes were rescued with reversal of cell growth and tumor sphere formation. Collectively, the results indicated that miR-34b-5p functions as a tumor suppressor in RB via regulating the Notch signaling pathway. Therefore, miR-34b-5p may be explored for its utility as a therapeutic target in RB.

Regulation of Hedgehog Signaling by miRNAs and Nanoformulations: A Possible Therapeutic Solution for Colorectal Cancer

Hedgehog (Hh) signaling aberrations trigger differentiation and proliferation in colorectal cancer (CRC). However, the current approaches which inhibit this vital cellular pathway provoke some side effects. Therefore, it is necessary to look for new therapeutic options. MicroRNAs are small molecules that modulate expression of the target genes and can be utilized as a potential therapeutic option for CRC. On the other hand, nanoformulations have been implemented in the treatment of plethora of diseases. Owing to their excessive bioavailability, limited cytotoxicity and high specificity, nanoparticles may be considered as an alternative drug delivery platform for the Hh signaling mediated CRC. This article reviews the Hh signaling and its involvement in CRC with focus on miRNAs, nanoformulations as potential diagnostic/prognostic and therapeutics for CRC.

Long noncoding RNA LINC00460 promotes the progression of cervical cancer via regulation of the miR-361-3p/Gli1 axis

Mounting evidence indicates that the long non-coding RNA (lncRNA) LINC00460 plays an oncogenic role in tumor progression; however, the role of LINC00460 in cervical cancer (CC) remains unknown. In this study, we found that LINC00460 was frequently upregulated in CC tissues and cell lines. Knockdown of LINC00460 repressed CC cell growth and invasion in vitro and attenuated tumorigenesis in vivo. Mechanistically, miR-361-3p was predicted as a direct target of LINC00460 by bioinformatics analysis, which was further confirmed by qRT-PCR, dual-luciferase reporter assays, and rescue experiments. Furthermore, miR-361-3p targeted the 3' untranslated region (UTR) of Gli1 mRNA and repressed its expression. Taken together, our study revealed that LINC00460 functions as an oncogenic lncRNA in CC, indicating the likely participation of the LINC00460/miR-361-3p/Gli1 pathway in the disease. Accordingly, our results provide new insight into CC tumorigenesis.

Upregulation of miR-361-3p suppresses serotonin-induced proliferation in human pulmonary artery smooth muscle cells by targeting SERT

Background

Abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs) is a key mechanism in pulmonary arterial hypertension (PAH). Serotonin (5-hydroxytryptamine, 5-HT) can induce abnormal proliferation of PASMCs. The role of miR-361-3p in serotonin-induced abnormal PASMCs proliferation remains unclear.

Methods

The miR-361-3p level was analyzed in plasma from PAH patients and normal controls and in human PASMCs (hPASMCs) using RT-PCR. The hPASMCs were transfected with an miR-361-3p mimic and then treated with serotonin. Untransfected hPASMCs were used as the control. Cell proliferation was evaluated using an MTS assay and 5-ethynyl-2′-deoxyuridine (EdU) staining. The cell cycle stages were evaluated using flow cytometry. The association between miR-361-3p and serotonin transporter (SERT) was determined using a luciferase reporter assay and anti-AGO2 RNA immunoprecipitation assay. The protein expression was evaluated via western blotting.

Results

The miR-361-3p level was lower in plasma from PAH patients than in plasma from the any of the normal control subjects. The mean pulmonary arterial pressure, pulmonary vascular resistance and pulmonary vascular resistance index were higher in PAH patients whose miR-361-3p level was lower than the median value for patients than in those whose miR-361-3p level was higher than the median. Serotonin treatment reduced miR-361-3p expression in the hPASMCs. MiR-361-3p overexpression suppressed cell proliferation, promoted apoptosis, induced G1 arrest, and decreased the phosphorylation level of ERK1/2 in serotonin-treated hPASMCs. SERT was identified as an miR-361-3p target. Its overexpression alleviated the effect of miR-361-3p overexpression on serotonin-induced hPASMC proliferation and upregulation of phosphorylated ERK1/2.

Conclusions

The miR-361-3p level is lower in the plasma of PAH patients. Upregulation of miR-361-3p suppresses serotonin-induced proliferation of hPASMCs by targeting SERT. Our results suggest that miR-361-3p is a potential therapeutic target in PAH.

Circular RNA has_circ_0000034 accelerates retinoblastoma advancement through the miR-361-3p/ADAM19 axis

Retinoblastoma (RB) is an intraocular malignancy that mainly occurs in infants and young children under 5 years of age. Circular RNA hsa_circ_0000034 (circ_0000034) was reported to be upregulated in RB tissues. Nevertheless, the function and mechanism of circ_0000034 in RB are unclear. Expression of circ_0000034, microRNA-361-3p (miR-361-3p), and a disintegrin and metalloproteinase 19 (ADAM19) was examined via quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability, migration, invasion, and apoptosis were determined though Cell Counting Kit-8 (CCK-8), transwell, or flow cytometry assays. Caspase-3 activity was detected using a caspase-3 activity assay kit. Some protein levels were examined using Western blot analysis. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay, or RNA pull-down assay were performed to verify the relationship between circ_0000034 or ADAM19 and miR-361-3p. The function of circ_0000034 in vivo was confirmed via animal experiment. We verified that circ_0000034 expression was elevated in RB tissues and cells. Circ_0000034 silencing reduced RB growth in vivo, repressed viability, migration, invasion, and EMT, and induced apoptosis of RB cells in vitro. Circ_0000034 acted as a sponge for miR-361-3p, which targeted ADAM19 in RB cells. Furthermore, the inhibition of miR-361-3p restored circ_0000034 knockdown-mediated impacts on viability, migration, invasion, apoptosis, and EMT of RB cells. Moreover, ADAM19 overexpression abolished the influence of miR-361-3p mimic on viability, migration, invasion, apoptosis, and EMT of RB cells. Circ_0000034 expedited RB progression through upregulating ADAM19 via sponging miR-361-3p, which indicated that circ_0000034 might a target for RB therapy.

Circular RNA UBAP2 contributes to tumor growth and metastasis of cervical cancer via modulating miR-361-3p/SOX4 axis

Background

Increasing researches have reported that circular RNA UBAP2 (circUBAP2) may be a potential prognosis biomarker and participate in the development of several cancers; however, the role of circUBAP2 in cervical cancer (CC) remains largely unclear.

Methods

We applied qRT-PCR and Western blot to examine expression levels of circUBAP2, miR-361-3p, SOX4, Bax, Bcl-2, Cleaved caspase 3, N-cadherin, Vimentin and E-cadherin. Cell proliferation, apoptosis, invasion and migration were analyzed by MTT assay, Flow cytometry, and Transwell assay, respectively. The interaction between miR-361-3p and circUBAP2 or SOX4 was confirmed by luciferase reporter assay and pull-down assay. Murine xenograft model was established by injecting SiHa cells which stably transfected sh-circUBAP2.

Results

CircUBAP2 was up-regulated in CC tissues and cell lines and high circUBAP2 expression predicated poor outcome. Knockdown of circUBAP2 suppressed cell proliferation, migration, invasion and EMT, while induced apoptosis in CC in vitro, and inhibited tumor growth and metastasis in vivo. MiR-361-3p directly bound to circUBAP2 or SOX4, and circUBAP2 could regulate SOX4 expression by sponging miR-361-3p in CC cells. Furthermore, rescue assay results demonstrated that the inhibitory effects of circUBAP2 knockdown on cell growth and metastasis were partially reversed by miR-361-3p down-regulation or SOX4 up-regulation in CC.

Conclusion

CircUBAP2 represents a prognostic marker and contributes to tumor growth and metastasis via modulating miR-361-3p/SOX4 axis in CC, which indicates a potential therapeutic target for CC treatment.

High-Throughput MicroRNA Profiling of Vitreoretinal Lymphoma: Vitreous and Serum MicroRNA Profiles Distinct from Uveitis

Purpose: Vitreoretinal lymphoma (VRL) is a non-Hodgkin lymphoma of the diffuse large B cell type (DLBCL), which is an aggressive cancer causing central nervous system related mortality. The pathogenesis of VRL is largely unknown. The role of microRNAs (miRNAs) has recently acquired remarkable importance in the pathogenesis of many diseases including cancers. Furthermore, miRNAs have shown promise as diagnostic and prognostic markers of cancers. In this study, we aimed to identify differentially expressed miRNAs and pathways in the vitreous and serum of patients with VRL and to investigate the pathogenesis of the disease. Materials and Methods: Vitreous and serum samples were obtained from 14 patients with VRL and from controls comprising 40 patients with uveitis, 12 with macular hole, 14 with epiretinal membrane, 12 healthy individuals. The expression levels of 2565 miRNAs in serum and vitreous samples were analyzed. Results: Expression of the miRNAs correlated significantly with the extracellular matrix (ECM) ‒receptor interaction pathway in VRL. Analyses showed that miR-326 was a key driver of B-cell proliferation, and miR-6513-3p could discriminate VRL from uveitis. MiR-1236-3p correlated with vitreous interleukin (IL)-10 concentrations. Machine learning analysis identified miR-361-3p expression as a discriminator between VRL and uveitis. Conclusions: Our findings demonstrate that aberrant microRNA expression in VRL may affect the expression of genes in a variety of cancer-related pathways. The altered serum miRNAs may discriminate VRL from uveitis, and serum miR-6513-3p has the potential to serve as an auxiliary tool for the diagnosis of VRL.

LncRNA BBOX1-AS1 upregulates HOXC6 expression through miR-361-3p and HuR to drive cervical cancer progression

Objectives

Over the past years, growing attention has been paid to deciphering the pivotal role of long non‐coding RNAs (lncRNAs) in regulating the occurrence and development of human malignancies, cervical cancer (CC) included. Nonetheless, the regulatory role of lncRNA BBOX1 antisense RNA 1 (BBOX1‐AS1) has not been explored as yet.

Material and Methods

The expression of BBOX1‐AS1 was detected by reverse transcription real‐time quantitative polymerase chain reaction (RT‐qPCR). Cell Counting Kit‐8 (CCK‐8), colony formation, TUNEL, Western blot, transwell and immunofluorescence assays testified the critical role of BBOX1‐AS1 in CC. The relationship between RNAs (BBOX1‐AS1, miR‐361‐3p, HOXC6 and HuR) was analysed by luciferase reporter, RNA Immunoprecipitation (RIP) and RNA pull‐down assays.

Results

BBOX1 antisense RNA 1 antisense RNA 1 was revealed to be highly expressed in CC. Decreased expression of BBOX1‐AS1 had suppressive effects on CC cell growth and migration. Molecular mechanism assays verified that BBOX1‐AS1 had negative interaction with miR‐361‐3p in CC. Additionally, homeobox C6 (HOXC6) was validated to be a downstream target of miR‐361‐3p in CC. Furthermore, ELAV‐like RNA‐binding protein 1, also known as HuR, was uncovered to be capable of regulating the mRNA stability of HOXC6 in CC. More importantly, rescue assays delineated that knockdown of HuR after overexpressing miR‐361‐3p could reverse BBOX1‐AS1 upregulation‐mediated effect on CC progression. Similarly, the function induced by BBOX1‐AS1 upregulation on CC progression could be countervailed by HOXC6 depletion.

Conclusions

BBOX1 antisense RNA 1 facilitates CC progression by upregulating HOXC6 expression via miR‐361‐3p and HuR.

Long noncoding RNA MALAT1 promotes high glucose-induced inflammation and apoptosis of vascular endothelial cells by regulating miR-361-3p/SOCS3 axis

Vascular complications are the important pathophysiologic manifestations of patients with diabetes mellitus (DM) and many long non-coding RNAs (LncRNAs) are involved in this process. In this study, we aimed to investigate the relationships among LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), microRNA-361-3p (miR-361-3p), and suppressor of cytokine signaling 3 (SOCS3) in high glucose (HG)-induced human umbilical vein endothelial cell (HUVEC) injury and its underlying mechanism. We found that HG treatment significantly promotes MALAT1 and SOCS3 expressions, but inhibits miR-361-3p expression in HUVECs. Furthermore, through bioinformatics analysis and dual luciferase assay, we found that MALAT1 directly sponges miR-361-3p to counteract its suppression on SOCS3 expression. Moreover, knockdown of MALAT1 evidently inhibits HG-induced inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 expressions in HUVECs (and HUVEC apoptosis) by regulating the miR-361-3p/SOCS3 axis. In conclusion, our results indicate that knockdown of MALAT1 inhibits HG-induced vascular endothelial injury through regulating miR-361-3p/SOCS3 axis, suggesting that inhibition of MALAT1 as a potential target for endothelial injury therapy for DM.

MicroRNA-361-3p is a potent therapeutic target for oral squamous cell carcinoma

MicroRNAs (miRNAs) can act not only as tumor suppressor genes but also as oncogenes. Oncogenic miRNAs (oncomiRs) could therefore provide opportunities for the treatment of human malignancies. Here, we aimed to identify oncomiRs present in oral squamous cell carcinoma (OSCC) and addressed whether targeting these miRNAs might be useful in treatment for cancer. Functional screening for oncomiRs in a human OSCC cell line (GFP‐SAS) was carried out using the miRCURY LNA microRNA Knockdown Library – Human version 12.0. We identified a locked nucleic acid (LNA)/DNA antisense oligonucleotide against miR‐361‐3p (LNA‐miR‐361‐3p) which showed the largest degree of growth inhibition of GFP‐SAS cells. Transfection with a synthetic mimic of mature miR‐361‐3p resulted in an approximately 20% increase in the growth of GFP‐SAS cells. We identified odd‐skipped related 2 (OSR2) as a miR‐361‐3p target gene. Transfection of GFP‐SAS cells with LNA‐miR‐361‐3p caused a significant increase in the expression levels of OSR2. Cotransfection of a OSR2 3′‐UTR luciferase reporter plasmid and LNA‐miR‐361‐3p into GFP‐SAS cells produced higher levels of luciferase activity than in cells cotransfected with the LNA‐nontarget. We assessed the effect of LNA‐miR‐361‐3p on the in vivo growth of GFP‐SAS cells. We found that LNA‐miR‐361‐3p significantly reduced the size of s.c. xenografted GFP‐SAS tumors, compared to the control group treated with LNA‐NT. Finally, we observed that miR‐361‐3p is overexpressed in OSCC tissues. These results suggest that miR‐361‐3p supports the growth of human OSCC cells both in vitro and in vivo and that targeting miR‐361‐3p could be a useful therapeutic approach for patients with OSCC.

miR-584 inhibits cell proliferation, migration and invasion in vitro and enhances the sensitivity to cisplatin in human cervical cancer by negatively targeting GLI1

Cervical cancer is the most lethal malignancy amongst women worldwide. MicroRNAs (miRNAs/miRs) play a critical role in the progression of cervical cancer. Compelling evidence indicates that miR-584 acts as a tumor suppressor in some types of cancers. However, the function of miR-584 in cervical cancer has not been illustrated. In the present study, the effects and mechanism of miR-584 in the process of proliferation, migration and invasion, and drug sensitivity to cisplatin in cervical cancer were determined. miR-584 expression decreased markedly in cervical cancer tissues and cell lines compared with healthy control samples. Dual-luciferase reporter assays confirmed that glioma-associated oncogene 1 (GLI1) is a novel molecular target of miR-584. The overexpression of miR-584 inhibited the expression of GLI1, reduced cell proliferation, migration and invasion, and induced apoptosis in HeLa cells. However, the silencing of miR-584 in CaSki cells produced the opposite effects. In addition, the overexpression of GLI1 in HeLa-cells overexpressing miR-584 markedly reversed the miR-584-induced inhibitory effect. Flow cytometry results showed that miR-584 enhanced cisplatin sensitivity by promoting chemotherapy-induced apoptosis. Therefore, miR-584 acted as a tumor suppressor miRNA and might be a novel target gene for future cervical cancer treatments.

Non-Coding RNAs in Retinoblastoma

Retinoblastoma (Rb) is the most common ocular pediatric malignancy that arises from the retina and is caused by a mutation of the two alleles of the tumor suppressor gene, RB1. Although early detection provides the opportunity of controlling the primary tumor with effective therapies, metastatic activity is fatal. Non-coding RNAs (ncRNAs) have emerged as important modifiers of a plethora of biological mechanisms including those involved in cancer. They are classified into short and long ncRNAs according to their length. Deregulation of all these molecules has also been shown to play a critical role in Rb pathogenesis and progression. It is believed that ncRNAs can provide new insights into novel regulatory mechanisms associated with clinical pathological characteristics, facilitating the development of therapeutic alternatives for the treatment of Rb. In this review, we describe a variety of ncRNAs, which capable of regulating the most likely candidate genes involved in the tumorigenesis of Rb, could prove useful in analyzing different aspects of this cancer.

circ-MYBL2 Serves As A Sponge For miR-361-3p Promoting Cervical Cancer Cells Proliferation And Invasion

Background

Circular RNAs (circRNAs) have been considered as a key regulator in tumor carcinogenesis. However, the roles and underlying mechanisms of circRNAs in cervical cancer (CC) remain largely unknown. In this study, we explored the effects of circ-MYBL2 (hsa_circ_0060467) on CC progression.

Methods

Levels of circ-MYBL2 and miR-361-3p were examined by qRT-PCR. CCK-8 assay, colony formation assay and transwell invasion assay were used to determine the roles of circ-MYBL2 in CC. Dual-luciferase reporter and RNA pull down assays were employed to verify the relationship between circ-MYBL2 and miR-361-3p.

Results

We showed that the expression of circ-MYBL2 was significantly upregulated and positively associated with advanced FIGO stage, larger tumor size, lymph node metastasis, and poor prognosis in CC patients. Function assays revealed that circ-MYBL2 inhibition suppressed CC cells’ proliferation, invasion and epithelial–mesenchymal transition (EMT) processes. In mechanism, miR-361-3p was identified as a direct target of circ-MYBL2, rescue assays showed that miR-361-3p suppression reversed the effects of si-circ-MYBL2 on CC cells’ progression.

Conclusion

Our findings suggested that circ-MYBL2 promoted CC progression by regulating miR-361-3p expression, which provided a novel therapeutic target for the treatment of CC patients.

Non-canonical Hedgehog Signaling Pathway in Cancer: Activation of GLI Transcription Factors Beyond Smoothened

The Hedgehog-GLI (HH-GLI) pathway is a highly conserved signaling that plays a critical role in controlling cell specification, cell–cell interaction and tissue patterning during embryonic development. Canonical activation of HH-GLI signaling occurs through binding of HH ligands to the twelve-pass transmembrane receptor Patched 1 (PTCH1), which derepresses the seven-pass transmembrane G protein-coupled receptor Smoothened (SMO). Thus, active SMO initiates a complex intracellular cascade that leads to the activation of the three GLI transcription factors, the final effectors of the HH-GLI pathway. Aberrant activation of this signaling has been implicated in a wide variety of tumors, such as those of the brain, skin, breast, gastrointestinal, lung, pancreas, prostate and ovary. In several of these cases, activation of HH-GLI signaling is mediated by overproduction of HH ligands (e.g., prostate cancer), loss-of-function mutations in PTCH1 or gain-of-function mutations in SMO, which occur in the majority of basal cell carcinoma (BCC), SHH-subtype medulloblastoma and rhabdomyosarcoma. Besides the classical canonical ligand-PTCH1-SMO route, mounting evidence points toward additional, non-canonical ways of GLI activation in cancer. By non-canonical we refer to all those mechanisms of activation of the GLI transcription factors occurring independently of SMO. Often, in a given cancer type canonical and non-canonical activation of HH-GLI signaling co-exist, and in some cancer types, more than one mechanism of non-canonical activation may occur. Tumors harboring non-canonical HH-GLI signaling are less sensitive to SMO inhibition, posing a threat for therapeutic efficacy of these antagonists. Here we will review the most recent findings on the involvement of alternative signaling pathways in inducing GLI activity in cancer and stem cells. We will also discuss the rationale of targeting these oncogenic pathways in combination with HH-GLI inhibitors as a promising anti-cancer therapies.