MiR-7-5p is frequently downregulated in glioblastoma microvasculature and inhibits vascular endothelial cell proliferation by targeting RAF1

microRNA involvement in the onset and progression of Barrett's esophagus: a systematic review

Esophageal adenocarcinoma (EAC) is a highly aggressive malignancy that develops from Barrett's esophagus (BE), an intestinal metaplasia of the distal esophagus. microRNAs (miRNAs), short non-coding regulatory RNAs, are frequently dysregulated in BE and are thought to play key roles in the onset of BE and its progression to EAC. miRNAs thus have potential diagnostic and prognostic value and are increasingly being used as cancer biomarkers. This review summarizes the current literature related to miRNAs that are dysregulated in BE within the context of Hedgehog, Notch, MAPK, NF kappa-B, Wnt and epithelial-mesenchymal transition (EMT) signaling which are thought to drive BE onset and progression. This comprehensive analysis of miRNAs and their associated signaling in the regulation of BE provides an overview of vital discoveries in this field and highlights gaps in our understanding of BE pathophysiology that warrant further investigation.

miR-7 Increases Cisplatin Sensitivity of Gastric Cancer Cells Through Suppressing mTOR

MicroRNAs have been reported to play an important role in diverse biological processes and cancer progression. MicroRNA-7 has been observed to be downregulated in human gastric cancer tissues, but the function of microRNA-7 in gastric cancer has not been well investigated. In this study, we demonstrate that the expression of microRNA-7 was significantly downregulated in 30 pairs of human gastric cancer tissues compared to adjacent normal tissues. Enforced expression of microRNA-7 inhibited cell proliferation and migration abilities of gastric cancer cells, BGC823 and SGC7901. Furthermore, microRNA-7 targeted mTOR in gastric cancer cells. In human clinical specimens, mTOR was higher expressed in gastric cancer tissues compared with adjacent normal tissues. More interestingly, microRNA-7 also sensitizes gastric cancer cells to cisplatin (CDDP) by targeting mTOR. Collectively, our results demonstrate that microRNA-7 is a tumor suppressor microRNA and indicate its potential application for the treatment of human gastric cancer in future.

Identification of the miRNA-target gene regulatory network in intracranial aneurysm based on microarray expression data

Intracranial aneurysm (IA) remains one of the most devastating neurological conditions. However, the pathophysiology of IA formation and rupture still remains unclear. The purpose of the present study was to identify the crucial microRNA (miRNA/miR) and genes involved in IAs and elucidate the mechanisms underlying the development of IAs. In the present study, novel miRNA regulation activities in IAs were investigated through the integration of public gene expression data of miRNA and mRNA using the Gene Expression Omnibus database, combined with bioinformatics prediction. A total of 15 differentially expressed miRNA and 1,447 differentially expressed mRNA between IAs and controls were identified. A number of miRNA-target gene pairs (770), whose expression levels were inversely correlated, were used to construct a regulatory network of miRNA-target genes in IAs. The biological functions and pathways of these target genes were revealed to be associated with IAs. Specific miRNA and genes, such as hsa-let-7f, hsa-let-7d, hsa-miR-7, RPS6KA3, TSC1 and IGF1 may possess key roles in the development of IAs. The integrated analysis in the present study may provide insights into the understanding of underlying molecular mechanisms of IAs and novel therapeutic targets.

Breviscapine suppresses the growth of non-small cell lung cancer by enhancing microRNA-7 expression

Breviscapine (BVP) has previously been shown to inhibit the proliferation of hepatocellular carcinoma cells. However, little is known about the effects of BVP on non-small cell lung cancer (NSCLC) growth. Here, we aimed to study the effects of BVP on human NSCLC growth. We employed A549, NCL-H460 and A549 cells transfected with microRNA-7 (miR-7) mimic and inhibitor to investigate the effect of BVP on cell proliferation, apoptosis and apoptosis-associated molecules. The results showed that BVP significantly reduced the growth of A549 and NCLH460 cells in a concentration-dependent and time-dependent manner, accompanied by a significant elevation of apoptosis. Additionally, the present study also confirmed that BVP-treated A549 cells showed increased levels of Bax and microRNA-7 (miR-7) and a decreased level of Bcl-2. The up-regulation of miR-7 enhanced the BVP sensitivity of NSCLC cells by suppressing cell proliferation and promoting cell apoptosis, while the inhibition of miR-7 reversed the anti-proliferative pro-apoptotic effects of BVP. Pre-treatment with miR-7 mimics enhanced the BVP-mediated down-regulation of Bax/Bcl-2 in NSCLC cells, while pre-treatment with the miR-7 inhibitor blocked the BVPmediated down-regulation of Bax/Bcl. Taken together, these results confirm that BVP effectively inhibits NSCLC proliferation and that miR-7, as a novel target, is likely involved in BVP-induced growth suppression and the apoptosis of NSCLC cells.

Circular RNA ciRS-7-A Promising Prognostic Biomarker and a Potential Therapeutic Target in Colorectal Cancer

Purpose: Colorectal cancer is one of the most common malignancies worldwide. Recently, a novel circular RNA, ciRS-7, was proposed to be a potential miR-7 sponge. As miR-7, a putative tumor-suppressor, regulates the expression of several important drivers of colorectal cancer, we analyzed the clinical significance of ciRS-7 in colorectal cancer patients.Experimental Design: Initially, we evaluated the expression levels of ciRS-7 in a training cohort comprising of 153 primary colorectal cancer tissues and 44 matched normal mucosae. We subsequently confirmed its clinical relevance in an independent validation cohort (n = 165), and evaluated the effect of ciRS-7 on miR-7, and its target genes EGFR and RAF1. Functional analyses were performed in cell lines and an animal model to support clinical findings.Results: Our data revealed that ciRS-7 was significantly upregulated in colorectal cancer tissues compared with matched normal mucosae (P = 0.0018), and its overexpression was associated with poor patient survival (P = 0.0224 and 0.0061 in the training and validation cohorts, respectively). Multivariate survival analysis revealed that ciRS-7 emerged as an independent risk factor for overall survival (P = 0.0656 and 0.0324 in the training and validation cohorts, respectively). Overexpression of ciRS-7 in HCT116 and HT29 cells led to the blocking of miR-7 and resulted in a more aggressive oncogenic phenotype, and ciRS-7 overexpression permitted the inhibition of miR-7 and subsequent activation of EGFR and RAF1 oncogenes.Conclusions: CiRS-7 is a promising prognostic biomarker in colorectal cancer patients and may serve as a therapeutic target for reducing EGFR-RAF1 activity in colorectal cancer patients. Clin Cancer Res; 23(14); 3918-28. ©2017 AACR.

Plasma miRNA expression profiles in rheumatoid arthritis associated interstitial lung disease

Background

Interstitial lung disease (ILD) is frequently associated with rheumatoid arthritis (RA), and is designated RA-associated ILD (RA-ILD). RA-ILD has a large impact on the prognosis of RA. Here, we investigated the micro RNAs (miRNAs) profiles to determine whether they may be useful for diagnosing RA-ILD.

Methods

RNA was isolated from plasma samples and cDNA was synthesized. Real-time RT-PCR analysis was performed to evaluate 752 miRNA expression profiles in plasma pools from RA patients with or without RA-ILD. Sixteen selected miRNA levels were analyzed in individual plasmas from 64 RA patients with or without RA-ILD.

Results

Expression levels of hsa-miR-214-5p (mean relative expression level ± standard deviation, 8.1 ± 28.2 in RA with ILD, 0.2 ± 0.9 in RA without ILD, P = 0.0156) and hsa-miR-7-5p (56.2 ± 260.4 in RA with ILD, 4.7 ± 11.8 in RA without ILD, P = 0.0362) were higher in RA patients with RA-ILD than in those without. The values of miRNA index (214, 7) generated from hsa-miR-214-5p and hsa-miR-7-5p for ILD were significantly elevated in RA patients with RA-ILD compared with those without (0.122 ± 0.332 in RA with ILD, 0.006 ± 0.013 in RA without ILD, P = 0.0010). The area under the curve value of the receiver operating characteristic curve for the miRNA index (214, 7) was 0.740.

Conclusions

To the best of our knowledge, this is the first report of miRNA profiles in RA-ILD. The expression levels of hsa-miR-214-5p and hsa-miR-7-5p were increased in RA with ILD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1389-4) contains supplementary material, which is available to authorized users.

Identification and bioinformatic analysis of dysregulated microRNAs in human oligodendroglial cells infected with borna disease virus

MicroRNAs (miRNAs) are recognized as important regulators of gene expression via translational depression or mRNA degradation. Previously, dysregulated miRNAs have been found in neurodegenerative and neuropsychiatric disorders. Borna disease virus (BDV) is a neurotropic, negative single‑stranded RNA virus, which may be a cause of human neuropsychiatric disease. BDV is regarded as an ideal model to analyze the molecular mechanisms of mental disorders caused by viral infection. In the present study, 10 miRNAs were dysregulated in human oligodendrocytes (OL cells) infected with the BDV strain, Hu‑H1 (OL/BDV). The predicted target genes of those different miRNAs were closely associated with DNA binding, receptor activity, cytoplasm and membrane, biopolymer metabolic process and signal transduction, which were ranked highest using Gene Ontology (GO) analysis, and were predominantly involved in 'Immune system and adaptive Immune system pathways' on pathway analysis. Reverse transcription‑quantitative polymerase chain reaction analysis confirmed that seven miRNAs (miR‑1290, miR‑1908, miR‑146a‑5p, miR‑424‑5p, miR‑3676‑3p, miR‑296‑3p and miR‑7‑5p) were significantly downregulated in the OL/BDV cells, whereas two miRNAs (miR‑1244 and miR‑4521) showed no significant differences between the two groups. The present study revealed for the first time, to the best of our knowledge, the miRNA profile of BDV Hu‑H1‑infected human OL cells. Based on GO and pathway analyses, further investigation of the signaling processes in BDV‑infected oligodendrocytes may offer particular promise in improving understanding of the neuropathogenesis of BDV.

Zinc and zinc-containing biomolecules in childhood brain tumors

Zinc ions are essential cofactors of a wide range of enzymes, transcription factors, and other regulatory proteins. Moreover, zinc is also involved in cellular signaling and enzymes inhibition. Zinc dysregulation, deficiency, over-supply, and imbalance in zinc ion transporters regulation are connected with various diseases including cancer. A zinc ion pool is maintained by two types of proteins: (i) zinc-binding proteins, which act as a buffer and intracellular donors of zinc and (ii) zinc transporters responsible for zinc fluxes into/from cells and organelles. The decreased serum zinc ion levels have been identified in patients suffering from various cancer diseases, including head and neck tumors and breast, prostate, liver, and lung cancer. On the contrary, increased zinc ion levels have been found in breast cancer and other malignant tissues. Zinc metalloproteomes of a majority of tumors including brain ones are still not yet fully understood. Current knowledge show that zinc ion levels and detection of certain zinc-containing proteins may be utilized for diagnostic and prognostic purposes. In addition, these proteins can also be promising therapeutic targets. The aim of the present work is an overview of the importance of zinc ions, zinc transporters, and zinc-containing proteins in brain tumors, which are, after leukemia, the second most common type of childhood cancer and the second leading cause of death in children after accidents.

MicroRNAs in glioblastoma multiforme pathogenesis and therapeutics

Glioblastoma multiforme (GBM) is the most common and lethal cancer of the adult brain, remaining incurable with a median survival time of only 15 months. In an effort to identify new targets for GBM diagnostics and therapeutics, recent studies have focused on molecular phenotyping of GBM subtypes. This has resulted in mounting interest in microRNAs (miRNAs) due to their regulatory capacities in both normal development and in pathological conditions such as cancer. miRNAs have a wide range of targets, allowing them to modulate many pathways critical to cancer progression, including proliferation, cell death, metastasis, angiogenesis, and drug resistance. This review explores our current understanding of miRNAs that are differentially modulated and pathologically involved in GBM as well as the current state of miRNA-based therapeutics. As the role of miRNAs in GBM becomes more well understood and novel delivery methods are developed and optimized, miRNA-based therapies could provide a critical step forward in cancer treatment.

Bystander autophagy mediated by radiation-induced exosomal miR-7-5p in non-targeted human bronchial epithelial cells

Radiation-induced bystander effect (RIBE) describes a set of biological effects in non-targeted cells that receive bystander signals from the irradiated cells. RIBE brings potential hazards to adjacent normal tissues in radiotherapy, and imparts a higher risk than previously thought. Excessive release of some substances from irradiated cells into extracellular microenvironment has a deleterious effect. For example, cytokines and reactive oxygen species have been confirmed to be involved in RIBE process via extracellular medium or gap junctions. However, RIBE-mediating signals and intercellular communication pathways are incompletely characterized. Here, we first identified a set of differentially expressed miRNAs in the exosomes collected from 2 Gy irradiated human bronchial epithelial BEP2D cells, from which miR-7-5p was found to induce autophagy in recipient cells. This exosome-mediated autophagy was significantly attenuated by miR-7-5p inhibitor. Moreover, our data demonstrated that autophagy induced by exosomal miR-7-5p was associated with EGFR/Akt/mTOR signaling pathway. Together, our results support the involvement of secretive exosomes in propagation of RIBE signals to bystander cells. The exosomes-containing miR-7-5p is a crucial mediator of bystander autophagy.

Inhibition of miR-7 promotes angiogenesis in human umbilical vein endothelial cells by upregulating VEGF via KLF4

Recent lentiviral-based microRNA (miRNA) library screening has identified miRNA-7 (miR-7) as an anti‑angiogenic miRNA in human umbilical vein endothelial cells (HUVECs). However, the underlying mechanism of miR-7 in the suppression of angiogenesis remains largely unknown. In the present study, we report that miR-7 inhibition promoted angiogenesis by upregulating vascular endothelial growth factor (VEGF) and directly targeting Krüppel-like factor 4 (KLF4). Downregulation of miR-7 promoted tube formation of HUVECs, accompanied by upregulation of mRNA and protein levels of both VEGF and KLF4. miR-7 directly targeted KLF4 as demonstrated by luciferase reporter assay and miR-7 mimics decreased KLF4. Furthermore, bioinformatic analysis revealed the presence of multiple DNA-binding elements of KLF4 in the VEGF promoter. Chromatin immunoprecipitation (ChIP) demonstrated that the KLF4 antibody specifically pulled down the VEGF promoter in the HUVECs. Furthermore, ectopic overexpression of KLF4 induced VEGF mRNA and protein levels. In addition, KLF4 silencing inhibited the angiogenesis induced by the miR-7 inhibitor in the HUVECs. Our results demonstrated that KLF4 is a direct target of miR-7 and a transcription activator of VEGF. These findings indicate that the miR-7-KLF4-VEGF signaling axis plays an important role in the regulation of angiogenesis in HUVECs, suggesting that miR-7 is a potential agent for the development of anti-angiogenic therapeutics in vascular diseases and solid tumors.

PPM1A Methylation Is Associated With Vascular Recurrence in Aspirin-Treated Patients

BACKGROUND AND PURPOSE

Despite great efforts by pharmacogenetic studies, the causes of aspirin failure to prevent the recurrence of ischemic events remain unclear. Our aim was to study whether epigenetics could be associated with the risk of vascular recurrence in aspirin-treated stroke patients.

METHODS

We performed an epigenetic joint analysis study in 327 patients treated with aspirin. In the discovery stage, we performed a nested case-control study in 38 matched ischemic stroke patients in whom 450 000 methylation sites were analyzed. Nineteen patients presented vascular recurrence after stroke, and 19 matched patients did not present vascular recurrence during the first year of follow-up. In a second stage, 289 new patients were analyzed by EpiTYPER.

RESULTS

The following 3 differentially methylated candidate CpG sites, were identified in the discovery stage and analyzed in the second stage: cg26039762 (P=9.69×10(-06), RAF1), cg04985020 (P=3.47×10(-03), PPM1A), and cg08419850 (P=3.47×10(-03), KCNQ1). Joint analysis identified an epigenome-wide association for cg04985020 (PPM1A; P=1.78×10(-07)), with vascular recurrence in patients treated with aspirin.

CONCLUSIONS

The pattern of differential methylation in PPM1A is associated with vascular recurrence in aspirin-treated stroke patients.

Differential expression of PDGFRB and EGFR in microvascular proliferation in glioblastoma

Glioblastoma (GBM) is the highly malignant glioma and exhibits microvascular proliferation. PCR mRNA arrays and immunohistochemical stains on tissue microarray demonstrated that the expression level of PDGFRB in GBM microvascular proliferation was significantly higher than that in GBM tumor cells while the expression level of EGFR was lower in microvascular proliferation than in GBM tumor cells. PDGFRB protein was selectively expressed in pericytes in GBM microvascular proliferation. By analyzing The Cancer Genome Atlas (TCGA) datasets for GBM, it was found that genomic DNA alterations were the main reason for the high expression of EGFR in GBM tumor cells. Our miRNA microarray data showed that microRNAs (miRNAs) (miR-193b-3p, miR-518b, miR-520f-3p, and miR-506-5p) targeting PDGFRB were downregulated in microvascular proliferation, which might be the most likely reason for the high expression of PDGFRB in GBM microvascular proliferation. The increase of several miRNAs (miR-133b, miR-30b-3p, miR-145-5p, and miR-146a-5p) targeting EGFR in GBM microvascular proliferation was one of the reasons for the lack of expression of EGFR in GBM microvascular proliferation. These findings implicated that miRNAs, such as miR-506, miR-133b, miR-145, and miR-146a, that target PDGFRB or EGFR, might be potential therapeutic agents for GBM. A new generation of targeted therapeutic agents against both EGFR and PDGFRB might be developed in the future.

ATP5A1 and ATP5B are highly expressed in glioblastoma tumor cells and endothelial cells of microvascular proliferation

Glioblastoma (GBM) is the most common primary malignant brain tumor. Microvascular proliferation is one of the characteristic pathologic features of GBM. Mitochondrial dysfunction plays an important role in the pathogenesis of GBM. In this study, microvascular proliferation from GBM and normal brain blood vessels were laser microdissected and total RNA was isolated from these microvasculatures. The difference of mRNA expression profiles among GBM microvasculature, normal brain blood vessels and GBM tumor cells was evaluated by mitochondria and metabolism PCR gene arrays. It was found that the mRNA levels of ATP5A1 and ATP5B in GBM tumor cells as well as microvascular proliferation were significantly higher compared with normal brain blood vessels. Immunohistochemical stains with anti-ATP5A1 antibody or anti-ATP5B antibody were performed on tissue microarray, which demonstrated strongly positive expression of ATP5A1 and ATP5B in GBM tumor cells and GBM microvascular proliferation while normal blood vessels were negative. By analyzing The Cancer Genome Atlas data sets for GBM and other cancers, genomic DNA alterations (mutation, amplification or deletion) were less likely the reason for the high expression of ATP5A1 and ATP5B in GBM. Our miRNA microarray data showed that miRNAs that target ATP5A1 or ATP5B were down-regulated, which might be the most likely reason for the high expression of ATP5A1 and ATP5B in GBM tumor cells and microvascular proliferation. These findings help us better understand the pathogenesis of GBM, and agents against ATP5A1 and/or ATP5B might effectively kill both tumor cells and microvascular proliferation in GBM. MiRNAs, such as Let-7f, miR-16, miR-23, miR-100 and miR-101, that target ATP5A1 or ATP5B, might be potential therapeutic agents for GBM.

MicroRNA-219-5p exerts tumor suppressor function by targeting ROBO1 in glioblastoma

Previous studies have shown that miR-219-5p is dysregulated and exerts tumor-suppressive effects in cancer development and progression. However, the molecular function and mechanism of miR-219-5p in glioblastoma growth and invasion are still unclear. In the present study, we show that miR-219-5p was downregulated in a panel of glioma tissues with different grades and in all the human glioma cell lines examined. Ectopic expression of miR-219-5p inhibited proliferation and invasion and induced apoptosis in vitro, and xenograft formation in vivo. ROBO1 was found to be a direct target of miR-219-5p, and when overexpressed in miR-219-5p-expressing glioma cells, was able to restore proliferative and invasive ability. Finally, in vivo investigation confirmed that miR-219-5p was a tumor suppressor that regulated ROBO1 expression. Taken together, these studies demonstrate that miR-219-5p inhibited cancer cell growth and invasion by direct targeting ROBO1, implicating miR-219-5p as an attractive candidate for cancer therapy.

MicroRNA-7: a promising new target in cancer therapy

The incidence of tumors with life-threatening effects has increased gradually over time; however, the mechanisms involved in tumor development have not been fully elucidated. Recent studies have shown that microRNA-7 (miR-7), which is endogenous non-coding RNA molecules of approximately 23 nucleotides, plays an important role in the occurrence and development of tumors as a key tumor suppressor. Mechanistic evidence showed that miR-7 is closely related to the growth, metastasis, and prognosis of various malignant tumors through regulating different target molecules, which suggest that miR-7 may be a new target for the clinical diagnosis and treatment of various tumors. In this review, we summarize current knowledge of the relationship between miR-7 and tumor development, diagnosis, and treatment.

Recent advance in molecular angiogenesis in glioblastoma: the challenge and hope for anti-angiogenic therapy

Glioblastoma (GBM) is the most highly malignant brain tumor in the human central nerve system. In this paper, we review new and significant molecular findings on angiogenesis and possible resistance mechanisms. Expression of a number of genes and regulators has been shown to be upregulated in GBM microvessel cells, such as interleukin-8, signal transducer and activator of transcription 3, Tax-interacting protein-1, hypoxia induced factor-1 and anterior gradient protein 2. The regulator factors that may strongly promote angiogenesis by promoting endothelial cell metastasis, changing the microenvironment, enhancing the ability of resistance to anti-angiogenic therapy, and that inhibit angiogenesis are reviewed. Based on the current knowledge, several potential targets and strategies are proposed for better therapeutic outcomes, such as its mRNA interference of DII4-Notch signaling pathway and depletion of b1 integrin expression. We also discuss possible mechanisms underlying the resistance to anti-angiogenesis and future directions and challenges in developing new targeted therapy for GBM.

Exploring miRNA-Associated Signatures with Diagnostic Relevance in Glioblastoma Multiforme and Breast Cancer Patients

The growing attention that non-coding RNAs have attracted in the field of cancer research in recent years is undeniable. Whether investigated as prospective therapeutic targets or prognostic indicators or diagnostic biomarkers, the clinical relevance of these molecules is starting to emerge. In addition, identification of non-coding RNAs in a plethora of body fluids has further positioned these molecules as attractive non-invasive biomarkers. This review will first provide an overview of the synthetic cascade that leads to the production of the small non-coding RNAs microRNAs (miRNAs) and presents their strengths as biomarkers of disease. Our interest will next be directed at exploring the diagnostic utility of miRNAs in two types of cancer: the brain tumor glioblastoma multiforme (GBM) and breast cancer. Finally, we will discuss additional clinical implications associated with miRNA detection as well as introduce other non-coding RNAs that have generated recent interest in the cancer research community.

Genome-wide small noncoding RNA profiling of pediatric high-grade gliomas reveals deregulation of several miRNAs, identifies downregulation of snoRNA cluster HBII-52 and delineates H3F3A and TP53 mutant-specific miRNAs and snoRNAs

Pediatric high-grade gliomas (HGGs) are highly malignant tumors that remain incurable and relatively understudied. The crucial role of noncoding RNAs (ncRNAs) has been reported in various cancers. However, the study on miRNAs in pediatric HGGs is scant and there is no report till date on the status of other small ncRNAs. Genome-wide microarray analysis was performed to investigate small ncRNA expression in pediatric HGG (n = 14) and compared to adult glioblastoma (GBM) signature. The validation of miRNAs and small nucleolar RNAs (snoRNAs) was done by real-time polymerase chain reaction. TP53 and H3F3A mutation-specific miRNA and snoRNA profiles were generated and analyzed. Pediatric HGGs showed upregulation of miR-17/92 and its paralog clusters (miR106b/25 and miR-106a/363), whereas majority of downregulated miRNAs belonged to miR379/656 cluster (14q32). Unsupervised hierarchical clustering identified two distinct groups. Interestingly, Group 2 with downregulated 14q32 cluster showed better overall survival. The miRNAs unique to pediatric HGG as compared to adult GBM were predicted to affect PDGFR and SMAD2/3 pathways. Similarities were seen between pediatric HGG and TP53 mutant miRNA profiles as compared to wild types. Several of H3F3A mutation-regulated genes were found to be the targets of H3F3A mutant-specific miRNAs. Remarkably, a significant downregulation of HBII-52 snoRNA cluster was found in pediatric HGGs, and was specific to H3F3A nonmutants. This is the first genome-wide profiling study on miRNAs and snoRNAs in pediatric HGGs with respect to H3F3A and TP53 mutations. The comparison of miRNA profiles of pediatric HGGs and adult GBM reiterates the overlaps and differences as also seen with their gene expression and methylation signatures.

The molecular mechanisms and therapeutic potential of microRNA-7 in cancer

INTRODUCTION

Increasing evidence supports that microRNAs (miRNAs) play crucial roles in cancer through post-transcriptional gene silencing of their target genes, therefore, more and more effort has been devoted to develop miRNA-targeting therapeutics in cancer. MicroRNA-7 (miR-7) has been characterized as a potential tumor suppressor and regulates diverse fundamental biological processes of cancer cells including initiation, proliferation, migration, invasion, survival and death by targeting a number of oncogenic signaling pathways.

AREAS COVERED

This review examines evidence of the biological responses of miR-7 in cancer, with an emphasis on its regulation of the vital oncogenic signaling pathways. It also discusses the rationale, strategies and challenges of miR-7 as a potential therapeutic target for cancer.

EXPERT OPINION

With the increasing understanding of molecular mechanisms of miR-7-mediated regulatory networks and the advancement of miRNA-based therapeutics, targeting miR-7 may be a potential and promising strategy for cancer therapy.