Overexpression of miR-128 specifically inhibits the truncated isoform of NTRK3 and upregulates BCL2 in SH-SY5Y neuroblastoma cells

Role of non-coding RNAs in neuroblastoma

Neuroblastoma is known as the most prevalent extracranial malignancy in childhood with a neural crest origin. It has been widely accepted that non-coding RNAs (ncRNAs) play important roles in many types of cancer, including glioma and gastrointestinal cancers. They may regulate the cancer gene network. According to recent sequencing and profiling studies, ncRNAs genes are deregulated in human cancers via deletion, amplification, abnormal epigenetic, or transcriptional regulation. Disturbances in the expression of ncRNAs may act either as oncogenes or as anti-tumor suppressor genes, and can lead to the induction of cancer hallmarks. ncRNAs can be secreted from tumor cells inside exosomes, where they can be transferred to other cells to affect their function. However, these topics still need more study to clarify their exact roles, so the present review addresses different roles and functions of ncRNAs in neuroblastoma.

Exploring the impact of miR-128 in inflammatory diseases: A comprehensive study on autoimmune diseases

microRNAs (miRNAs) play a crucial role in various biological processes, including immune system regulation, such as cell proliferation, tolerance (central and peripheral), and T helper cell development. Dysregulation of miRNA expression and activity can disrupt immune responses and increase susceptibility to neuroimmune disorders. Conversely, miRNAs have been shown to have a protective role in modulating immune responses and preventing autoimmunity. Specifically, reducing the expression of miRNA-128 (miR-128) in an Alzheimer's disease (AD) mouse model has been found to improve cognitive deficits and reduce neuropathology. This comprehensive review focuses on the significance of miR-128 in the pathogenesis of neuroautoimmune disorders, including multiple sclerosis (MS), AD, Parkinson's disease (PD), Huntington's disease (HD), epilepsy, as well as other immune-mediated diseases such as inflammatory bowel disease (IBD) and rheumatoid arthritis (RA). Additionally, we present compelling evidence supporting the potential use of miR-128 as a diagnostic or therapeutic biomarker for neuroimmune disorders. Collectively, the available literature suggests that targeting miR-128 could be a promising strategy to alleviate the behavioral symptoms associated with neuroimmune diseases. Furthermore, further research in this area may uncover new insights into the molecular mechanisms underlying these disorders and potentially lead to the development of novel therapeutic approaches.

The Role of miR-128 in Neurodegenerative Diseases

Several neurodegenerative disorders are characterized by the accumulation of misfolded proteins and are collectively known as proteinopathies. Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD) represent some of the most common neurodegenerative disorders whose steady increase in prevalence is having a major socio-economic impact on our society. Multiple laboratories have reported hundreds of changes in gene expression in selective brain regions of AD, PD, and HD brains. While the mechanisms underlying these changes remain an active area of investigation, alterations in the expression of noncoding RNAs, which are common in AD, PD, and HD, may account for some of the changes in gene expression in proteinopathies. In this review, we discuss the role of miR-128, which is highly expressed in mammalian brains, in AD, PD, and HD. We highlight how alterations in miR-128 may account, at least in part, for the gene expression changes associated with proteinopathies. Indeed, miR-128 is involved, among other things, in the regulation of neuronal plasticity, cytoskeletal organization, and neuronal death, events linked to various proteinopathies. For example, reducing the expression of miR-128 in a mouse model of AD ameliorates cognitive deficits and reduces neuropathology. Overall, the data in the literature suggest that targeting miR-128 might be beneficial to mitigate the behavioral phenotype associated with these diseases.

SIV Infection Regulates Compartmentalization of Circulating Blood Plasma miRNAs within Extracellular Vesicles (EVs) and Extracellular Condensates (ECs) and Decreases EV-Associated miRNA-128

Background: This is Manuscript 1 of a two-part Manuscript of the same series. Here, we present findings from our first set of studies on the abundance and compartmentalization of blood plasma extracellular microRNAs (exmiRNAs) into extracellular particles, including blood plasma extracellular vesicles (EVs) and extracellular condensates (ECs) in the setting of untreated HIV/SIV infection. The goals of the study presented in this Manuscript 1 are to (i) assess the abundance and compartmentalization of exmiRNAs in EVs versus ECs in the healthy uninfected state, and (ii) evaluate how SIV infection may affect exmiRNA abundance and compartmentalization in these particles. Considerable effort has been devoted to studying the epigenetic control of viral infection, particularly in understanding the role of exmiRNAs as key regulators of viral pathogenesis. MicroRNA (miRNAs) are small (~20-22 nts) non-coding RNAs that regulate cellular processes through targeted mRNA degradation and/or repression of protein translation. Originally associated with the cellular microenvironment, circulating miRNAs are now known to be present in various extracellular environments, including blood serum and plasma. While in circulation, miRNAs are protected from degradation by ribonucleases through their association with lipid and protein carriers, such as lipoproteins and other extracellular particles-EVs and ECs. Functionally, miRNAs play important roles in diverse biological processes and diseases (cell proliferation, differentiation, apoptosis, stress responses, inflammation, cardiovascular diseases, cancer, aging, neurological diseases, and HIV/SIV pathogenesis). While lipoproteins and EV-associated exmiRNAs have been characterized and linked to various disease processes, the association of exmiRNAs with ECs is yet to be made. Likewise, the effect of SIV infection on the abundance and compartmentalization of exmiRNAs within extracellular particles is unclear. Literature in the EV field has suggested that most circulating miRNAs may not be associated with EVs. However, a systematic analysis of the carriers of exmiRNAs has not been conducted due to the inefficient separation of EVs from other extracellular particles, including ECs. Methods: Paired EVs and ECs were separated from EDTA blood plasma of SIV-uninfected male Indian rhesus macaques (RMs, n = 15). Additionally, paired EVs and ECs were isolated from EDTA blood plasma of combination anti-retroviral therapy (cART) naïve SIV-infected (SIV+, n = 3) RMs at two time points (1- and 5-months post infection, 1 MPI and 5 MPI). Separation of EVs and ECs was achieved with PPLC, a state-of-the-art, innovative technology equipped with gradient agarose bead sizes and a fast fraction collector that allows high-resolution separation and retrieval of preparative quantities of sub-populations of extracellular particles. Global miRNA profiles of the paired EVs and ECs were determined with RealSeq Biosciences (Santa Cruz, CA) custom sequencing platform by conducting small RNA (sRNA)-seq. The sRNA-seq data were analyzed using various bioinformatic tools. Validation of key exmiRNAs was performed using specific TaqMan microRNA stem-loop RT-qPCR assays. Results: We showed that exmiRNAs in blood plasma are not restricted to any type of extracellular particles but are associated with lipid-based carriers-EVs and non-lipid-based carriers-ECs, with a significant (~30%) proportion of the exmiRNAs being associated with ECs. In the blood plasma of uninfected RMs, a total of 315 miRNAs were associated with EVs, while 410 miRNAs were associated with ECs. A comparison of detectable miRNAs within paired EVs and ECs revealed 19 and 114 common miRNAs, respectively, detected in all 15 RMs. Let-7a-5p, Let-7c-5p, miR-26a-5p, miR-191-5p, and let-7f-5p were among the top 5 detectable miRNAs associated with EVs in that order. In ECs, miR-16-5p, miR-451, miR-191-5p, miR-27a-3p, and miR-27b-3p, in that order, were the top detectable miRNAs in ECs. miRNA-target enrichment analysis of the top 10 detected common EV and EC miRNAs identified MYC and TNPO1 as top target genes, respectively. Functional enrichment analysis of top EV- and EC-associated miRNAs identified common and distinct gene-network signatures associated with various biological and disease processes. Top EV-associated miRNAs were implicated in cytokine-cytokine receptor interactions, Th17 cell differentiation, IL-17 signaling, inflammatory bowel disease, and glioma. On the other hand, top EC-associated miRNAs were implicated in lipid and atherosclerosis, Th1 and Th2 cell differentiation, Th17 cell differentiation, and glioma. Interestingly, infection of RMs with SIV revealed that the brain-enriched miR-128-3p was longitudinally and significantly downregulated in EVs, but not ECs. This SIV-mediated decrease in miR-128-3p counts was validated by specific TaqMan microRNA stem-loop RT-qPCR assay. Remarkably, the observed SIV-mediated decrease in miR-128-3p levels in EVs from RMs agrees with publicly available EV miRNAome data by Kaddour et al., 2021, which showed that miR-128-3p levels were significantly lower in semen-derived EVs from HIV-infected men who used or did not use cocaine compared to HIV-uninfected individuals. These findings confirmed our previously reported finding and suggested that miR-128 may be a target of HIV/SIV. Conclusions: In the present study, we used sRNA sequencing to provide a holistic understanding of the repertoire of circulating exmiRNAs and their association with extracellular particles, such as EVs and ECs. Our data also showed that SIV infection altered the profile of the miRNAome of EVs and revealed that miR-128-3p may be a potential target of HIV/SIV. The significant decrease in miR-128-3p in HIV-infected humans and in SIV-infected RMs may indicate disease progression. Our study has important implications for the development of biomarker approaches for various types of cancer, cardiovascular diseases, organ injury, and HIV based on the capture and analysis of circulating exmiRNAs.

MicroRNAs as prospective biomarkers, therapeutic targets and pharmaceuticals in neuroblastoma

Neuroblastomas, the most prevalent malignant solid neoplasms of childhood, originate from progenitor cells of the sympathetic nervous system. Their genetic causation is diverse and involves multiple molecular mechanisms. This review highlights multiple roles of microRNA in neuroblastoma pathogenesis and discusses the prospects of harnessing these important natural regulator molecules as biomarkers, therapeutic targets and pharmaceuticals in neuroblastoma.

The role of miR-128 in cancer development, prevention, drug resistance, and immunotherapy

A growing body of evidence has revealed that microRNA (miRNA) expression is dysregulated in cancer, and they can act as either oncogenes or suppressors under certain conditions. Furthermore, some studies have discovered that miRNAs play a role in cancer cell drug resistance by targeting drug-resistance-related genes or influencing genes involved in cell proliferation, cell cycle, and apoptosis. In this regard, the abnormal expression of miRNA-128 (miR-128) has been found in various human malignancies, and its verified target genes are essential in cancer-related processes, including apoptosis, cell propagation, and differentiation. This review will discuss the functions and processes of miR-128 in multiple cancer types. Furthermore, the possible involvement of miR-128 in cancer drug resistance and tumor immunotherapeutic will be addressed.

A Review of Molecular Interplay between Neurotrophins and miRNAs in Neuropsychological Disorders

Various neurotrophins (NTs), including nerve growth factor, brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4, promote cellular differentiation, survival, and maintenance, as well as synaptic plasticity, in the peripheral and central nervous system. The function of microRNAs (miRNAs) and other small non-coding RNAs, as regulators of gene expression, is pivotal for the appropriate control of cell growth and differentiation. There are positive and negative loops between NTs and miRNAs, which exert modulatory effects on different signaling pathways. The interplay between NTs and miRNAs plays a crucial role in the regulation of several physiological and pathological brain procedures. Emerging evidence suggests the diagnostic and therapeutic roles of the interactions between NTs and miRNAs in several neuropsychological disorders, including epilepsy, multiple sclerosis, Alzheimer's disease, Huntington's disease, amyotrophic lateral sclerosis, schizophrenia, anxiety disorders, depression, post-traumatic stress disorder, bipolar disorder, and drug abuse. Here, we review current data regarding the regulatory interactions between NTs and miRNAs in neuropsychological disorders, for which novel diagnostic and/or therapeutic strategies are emerging. Targeting NTs-miRNAs interactions for diagnostic or therapeutic approaches needs to be validated by future clinical studies.

Suppressed miR-128-3p combined with TERT overexpression predicts dismal outcomes for neuroblastoma

BACKGROUND

Molecular and clinical diversity of neuroblastomas is notorious. The activating TERT rearrangements have been associated with dismal prognosis. Suppression of miR-128-3p may complement and enhance the adverse effects of TERT overexpression.

OBJECTIVE

The study aimed at evaluation of prognostic significance of the miR-128-3p/TERT expression in patients with primary neuroblastoma.

METHODS

RNA samples isolated from fresh-frozen tumor specimens (n= 103) were reverse transcribed for evaluation of miR-128-3p and TERT expression by qPCR. The normalized expression levels were tested for correlations with the event-free survival (EFS). ROC-analysis was used to establish threshold expression levels (TLs) for the possible best prediction of the outcomes. The median follow-up was 57 months.

RESULTS

Both TERT overexpression and miR-128-3p downregulation were independently associated with superior rates of adverse events (p= 0.027, TL =-2.32 log10 and p= 0.080, TL =-1.33 log10, respectively). The MYCN single-copy patients were stratified into groups based on the character of alterations in expression of the studied transcripts. Five-year EFS in the groups of patients with elevated TERT/normal miR-128-3p expression and normal TERT/reduced miR-128-3p expression were 0.74 ± 0.08 and 0.60 ± 0.16, respectively. The patients with elevated TERT/reduced miR-128-3p expression had the worst outcomes, with 5-year EFS of 0.40 ± 0.16 compared with 0.91 ± 0.06 for the patients with unaltered levels of both transcripts (p< 0.001). Cumulative incidence of relapse/progression for the groups constituted 0.23 ± 0.08, 0.40 ± 0.16, 0.60 ± 0.16 and 0.09 ± 0.06, respectively. Moreover, the loss of miR-128-3p was qualified as independent adverse predictor which outperformed the conventional clinical and genetic risk factors in the multivariate Cox regression model of EFS.

CONCLUSIONS

Combined expression levels of miR-128-3p and TERT represent a novel prognostic biomarker for neuroblastoma.

Identifying Key MicroRNA Signatures for Neurodegenerative Diseases With Machine Learning Methods

Neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease, and many other disease types, cause cognitive dysfunctions such as dementia via the progressive loss of structure or function of the body's neurons. However, the etiology of these diseases remains unknown, and diagnosing less common cognitive disorders such as vascular dementia (VaD) remains a challenge. In this work, we developed a machine-leaning-based technique to distinguish between normal control (NC), AD, VaD, dementia with Lewy bodies, and mild cognitive impairment at the microRNA (miRNA) expression level. First, unnecessary miRNA features in the miRNA expression profiles were removed using the Boruta feature selection method, and the retained feature sets were sorted using minimum redundancy maximum relevance and Monte Carlo feature selection to provide two ranking feature lists. The incremental feature selection method was used to construct a series of feature subsets from these feature lists, and the random forest and PART classifiers were trained on the sample data consisting of these feature subsets. On the basis of the model performance of these classifiers with different number of features, the best feature subsets and classifiers were identified, and the classification rules were retrieved from the optimal PART classifiers. Finally, the link between candidate miRNA features, including hsa-miR-3184-5p, has-miR-6088, and has-miR-4649, and neurodegenerative diseases was confirmed using recently published research, laying the groundwork for more research on miRNAs in neurodegenerative diseases for the diagnosis of cognitive impairment and the understanding of potential pathogenic mechanisms.

LINC02381-ceRNA exerts its oncogenic effect through regulation of IGF1R signaling pathway in glioma

PURPOSE

LncRNAs play essential roles in the cellular and molecular biology of glioma. Some LncRNAs exert their role through sponging miRNAs and regulating multiple signaling pathways. LINC02381 is involved in several cancer types as either oncogene or tumor suppressor. Here, we intended to find the molecular mechanisms of the LINC02381 effect during the glioma progression in related cell lines.

METHODS AND RESULTS

RNA-seq data analysis indicated the oncogenic characteristics of LINC02381, and RT-qPCR results confirmed its upregulation compared to normal tissues. Besides its expression was relatively stronger in invasive glioma cell lines. Furthermore, in silico analysis revealed LINC02381 is concentrated in the cytoplasm and predicted its sponging effect against miR-128 and miR-150, which was verified through dual luciferase assay. When LINC02381 was overexpressed in 1321N1, U87, and A172 cell lines, IGF1R and TrkC receptors as well as their downstream pathways (PI3K and RAS/MAPK), were upregulated, detected by RT-qPCR, and verified by western analysis. Consistently, LINC02381 overexpression was followed by an increased proliferation rate of transfected glioma cell lines, detected by flow cytometry and MTT assay, and RT-qPCR. It also resulted in elevated EMT and stemness markers expression level, increased migration rate, and reduced apoptosis rate, detected by RT-qPCR, western analysis, scratch test, and Annexin/PI flow cytometry analysis, respectively.

CONCLUSION

The overall results indicated that LINC02381 exerts its oncogenic effect in glioma cells through sponging miR-128 and miR-150 to upregulate the IGF1R signaling pathway. Our results introduce LINC02381 and miR-128, and miR-150 as potential prognosis and therapy targets for the treatment of glioma.

Exosomal microRNAs from mesenchymal stem/stromal cells: Biology and applications in neuroprotection

Mesenchymal stem/stromal cells (MSCs) are extensively studied as cell-therapy agents for neurological diseases. Recent studies consider exosomes secreted by MSCs as important mediators for MSCs’ neuroprotective functions. Exosomes transfer functional molecules including proteins, lipids, metabolites, DNAs, and coding and non-coding RNAs from MSCs to their target cells. Emerging evidence shows that exosomal microRNAs (miRNAs) play a key role in the neuroprotective properties of these exosomes by targeting several genes and regulating various biological processes. Multiple exosomal miRNAs have been identified to have neuroprotective effects by promoting neurogenesis, neurite remodeling and survival, and neuroplasticity. Thus, exosomal miRNAs have significant therapeutic potential for neurological disorders such as stroke, traumatic brain injury, and neuroinflammatory or neurodegenerative diseases and disorders. This review discusses the neuroprotective effects of selected miRNAs (miR-21, miR-17-92, miR-133, miR-138, miR-124, miR-30, miR146a, and miR-29b) and explores their mechanisms of action and applications for the treatment of various neurological disease and disorders. It also provides an overview of state-of-the-art bioengineering approaches for isolating exosomes, optimizing their yield and manipulating the miRNA content of their cargo to improve their therapeutic potential.

The Neurotrophin Receptor TrkC as a Novel Molecular Target of the Antineuroblastoma Action of Valproic Acid

Neurotrophins and their receptors are relevant factors in controlling neuroblastoma growth and progression. The histone deacetylase (HDAC) inhibitor valproic acid (VPA) has been shown to downregulate TrkB and upregulate the p75NTR/sortilin receptor complex. In the present study, we investigated the VPA effect on the expression of the neurotrophin-3 (NT-3) receptor TrkC, a favorable prognostic marker of neuroblastoma. We found that VPA induced the expression of both full-length and truncated (TrkC-T1) isoforms of TrkC in human neuroblastoma cell lines without (SH-SY5Y) and with (Kelly, BE(2)-C and IMR 32) MYCN amplification. VPA enhanced cell surface expression of the receptor and increased Akt and ERK1/2 activation by NT-3. The HDAC inhibitors entinostat, romidepsin and vorinostat also increased TrkC in SH-SY5Y, Kelly and BE(2)-C but not IMR 32 cells. TrkC upregulation by VPA involved induction of RUNX3, stimulation of ERK1/2 and JNK, and ERK1/2-mediated Egr1 expression. In SH-SY5Y cell monolayers and spheroids the exposure to NT-3 enhanced the apoptotic cascade triggered by VPA. Gene silencing of both TrkC-T1 and p75NTR prevented the NT-3 proapoptotic effect. Moreover, NT-3 enhanced p75NTR/TrkC-T1 co-immunoprecipitation. The results indicate that VPA upregulates TrkC by activating epigenetic mechanisms and signaling pathways, and sensitizes neuroblastoma cells to NT-3-induced apoptosis.

MiRNA-128-3p Restrains Malignant Melanoma Cell Malignancy by Targeting NTRK3

The functions of non-coding RNA, including microRNA (miRNA), have attracted considerable attention in the field of oncology, In this report, we examined the roles and molecular mechanisms of miR-128-3p, as related to the biological behaviors of malignant melanoma (MM). We found that miR-128-3p was expressed in low levels in these MM cells and may serve as a tumor suppressor by inhibiting proliferation, migration, and invasion, as well as inducing apoptosis in these MM cells. Moreover, neurotrophin receptor 3 (NTRK3), which serves as an oncogene that can enhance malignant behaviors of MM cells, was up-regulated in MM cells. Our current survey disclosed a complementary binding between miR-128-3p and the NTRK3 3' untranslated regions (3'-UTR), while luciferase activities of NTRK3 3'-UTR were restrained by miR-128-3p in 293T cells. The effects of pre-miR-128-3p and sh-NTRK3 as well as anti-miR-128-3p and NTRK3(+) appeared to function synergistically in producing malignant progression. Moreover, there were possible to have counteracted effects for pre-miR-128-3p and NTRK3(+) in malignant progression. These findings established that miR-128-3p can function as a tumor suppressor by inhibiting carcinogenesis of the oncogene, NTRK3. Collectively, miR-128-3p and NTRK3 genes participate in modulating the malignant behavior of MM, and may represent new therapeutic targets for MM.

MiR-128 suppresses metastatic capacity by targeting metadherin in breast cancer cells

Background

Breast cancer, the most common cancer in women worldwide, causes the vast majority of cancer-related deaths. Undoubtedly, tumor metastasis and recurrence are responsible for more than 90 percent of these deaths. MicroRNAs are endogenous noncoding RNAs that have been integrated into almost all the physiological and pathological processes, including metastasis. In the present study, the role of miR-128 in breast cancer was investigated.

Results

Compared to the corresponding adjacent normal tissue, the expression of miR-128 was significantly suppressed in human breast cancer specimens. More importantly, its expression level was reversely correlated to histological grade of the cancer. Ectopic expression of miR-128 in the aggressive breast cancer cell line MDA-MB-231 could inhibit cell motility and invasive capacity remarkably. Afterwards, Metadherin (MTDH), also known as AEG-1 (Astrocyte Elevated Gene 1) and Lyric that implicated in various aspects of cancer progression and metastasis, was further identified as a direct target gene of miR-128 and its expression level was up-regulated in clinical samples as expected. Moreover, knockdown of MTDH in MDA-MB-231 cells obviously impaired the migration and invasion capabilities, whereas re-expression of MTDH abrogated the suppressive effect caused by miR-128.

Conclusions

Overall, these findings demonstrate that miR-128 could serve as a novel biomarker for breast cancer metastasis and a potent target for treatment in the future.

Expression and clinical value of miR-128 and IGF-1 in patients with acute ischemic stroke

BACKGROUND

The aim of this study is to investigate the expression and clinical value of miRNA-128 (miR-128) and insulin-like growth factor-1 (IGF-1) in patients with acute ischemic stroke (AIS).

METHODS

Eighty patients with acute ischemic stroke hospitalized in Rizhao Hospital of TCM from August 2016 to August 2018 were selected as the experimental group. Sixty healthy patients with normal physical examination during the same period were selected as the control group. The expression levels of miR-128 and IGF-1 were compared between the two groups and between AIS patients with different levels of nervous functional defects, different infarct size and different prognosis. ROC curve of serum miR-128 and IGF-1 expressions for AIS diagnosis alone and in combination was analyzed.

RESULTS

The expression level of miR-128 in the serum of patients in the experimental group was higher than that of the control group, and the expression level of IGF-1 was lower than that of the control group (P<0.001). The serum miR-128 expression of patients in the ineffective group was higher than that of the effective group, and the expression of IGF-1 was lower than that of the effective group (P<0.001). The expression level of serum miR-128 in AIS patients was higher than that in healthy subjects and increased with the aggravation of the disease. The expression level of IGF-1 of AIS patients was lower than that of healthy subjects and decreased with the aggravation of the disease. The two factors were involved in the formation and deterioration of the disease.

CONCLUSIONS

The expression levels can reflect the severity of the disease to a certain extent and provide references for the early diagnosis and prognostic treatment in patients with acute ischemic stroke.

Roles of TrkC Signaling in the Regulation of Tumorigenicity and Metastasis of Cancer

Tropomyosin receptor kinase (Trk) C contributes to the clinicopathology of a variety of human cancers, and new chimeric oncoproteins containing the tyrosine kinase domain of TrkC occur after fusion to the partner genes. Overexpression of TrkC and TrkC fusion proteins was observed in patients with a variety of cancers, including mesenchymal, hematopoietic, and those of epithelial cell lineage. Both microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) were involved in the regulation of TrkC expression through transcriptional and posttranscriptional alteration. Aberrant activation of TrkC and TrkC fusion proteins markedly induces the epithelial-mesenchymal transition (EMT) program, growth rate, tumorigenic capacity via constitutive activation of Ras-MAP kinase (MAPK), PI3K-AKT, and the JAK2-STAT3 pathway. The clinical trial of TrkC or TrkC fusion-positive cancers with newly developed Trk inhibitors demonstrated that Trk inhibitors were highly effective in inducing tumor regression in patients who do not harbor mutations in the kinase domain. Recently, there has been a progressive accumulation of mutations in TrkC or the TrkC fusion protein detected in the clinic and its related cancer cell lines caused by high-throughput DNA sequencing. Despite given the high overall response rate against Trk or Trk fusion proteins-positive solid tumors, acquired drug resistance was observed in patients with various cancers caused by mutations in the Trk kinase domain. To overcome acquired resistance caused by kinase domain mutation, next-generation Trk inhibitors have been developed, and these inhibitors are currently under investigation in clinical trials.

MicroRNAs in neuroblastoma tumorigenesis, therapy resistance, and disease evolution

Neuroblastoma (NB) deriving from neural crest cells is the most common extra-cranial solid cancer at infancy. NB originates within the peripheral sympathetic ganglia in adrenal medulla and along the midline of the body. Clinically, NB exhibits significant heterogeneity stretching from spontaneous regression to rapid progression to therapy resistance. MicroRNAs (miRNAs, miRs) are small (19-22 nt in length) non-coding RNAs that regulate human gene expression at the post-transcriptional level and are known to regulate cellular signaling, growth, differentiation, death, stemness, and maintenance. Consequently, the function of miRs in tumorigenesis, progression and resistance is of utmost importance for the understanding of dysfunctional cellular pathways that lead to disease evolution, therapy resistance, and poor clinical outcomes. Over the last two decades, much attention has been devoted to understanding the functional roles of miRs in NB biology. This review focuses on highlighting the important implications of miRs within the context of NB disease progression, particularly miRs’ influences on NB disease evolution and therapy resistance. In this review, we discuss the functions of both the “oncomiRs” and “tumor suppressor miRs” in NB progression/therapy resistance. These are the critical components to be considered during the development of novel miR-based therapeutic strategies to counter therapy resistance.

Plk2 Regulated by miR-128 Induces Ischemia-Reperfusion Injury in Cardiac Cells

Ischemia-reperfusion (I/R) injury occurs during cardiac surgery and is the major factor leading to heart dysfunction and heart failure. Our previous study showed that gene and microRNA expression profiles are altered in heart grafts with extended I/R injury. In this study, we, for the first time, demonstrated that I/R injury upregulates the expression of Polo-like kinase 2 (Plk2) but decreases miR-128 expression in heart cells both in vitro and in vivo. Silencing Plk2 using small interfering RNA (siRNA) protects cells from Antimycin A-induced cell apoptosis/death. Silencing Plk2 also decreases phosphorylated p65 expression but increases Angiopoietin 1 expression. In addition, Plk2 is negatively regulated by miR-128. miR-128 exerts a protective effect on cell apoptosis similar to Plk2 siRNA in response to I/R stress. Methylation inhibitor 5-azacytidine (5-AZ) increases the expression of miR-128 and subsequently reduces Plk2 expression and cell apoptosis. In conclusion, this study demonstrated that Plk2 regulated by miR-128 induces cell apoptosis/death in response to I/R stress through activation of the nuclear factor κB (NF-κB) signal pathway. miR-128 and Plk2 are new targets for preventing cardiac I/R injury or oxidative stress-mediated injury.

MicroRNA signature associated with treatment response in myasthenia gravis: A further step towards precision medicine

Myasthenia gravis (MG) is an autoimmune disorder affecting neuromuscular transmission currently treated with chronic immunosuppression. Inter-subject variation in treatment response and side effects highlight the need for personalized therapies by identification of biomarkers predictive of drug efficacy in individual patients, still lacking in MG. MicroRNAs (miRNAs) play a key role in immune response and drug metabolism modulation. This study, part of an Italian-Israeli collaborative project, aimed to identify specific miRNAs as biomarkers associated with immunosuppressive treatment response in MG patients. Whole miRNome sequencing, followed by miRNA validation by real-time PCR, was performed in peripheral blood from Italian MG patients (n = 40) classified as responder and non-responder to immunosuppressive therapies. MiRNA sequencing identified 41 miRNAs differentially expressed in non-responder compared to responder Italian MG patients. Validation phase pointed out three miRNAs, miR-323b-3p, -409-3p, and -485-3p, clustered on chromosome 14q32.31, the levels of which were significantly decreased in non-responder versus responder patients, whereas miR-181d-5p and -340-3p showed an opposite trend. ROC curve analysis showed sensitivity and specificity performance results indicative of miR-323b-3p, -409-3p, and -485-3p predictive value for responsiveness to immunosuppressive drugs in MG. Validated miRNAs were further analyzed in blood from responder and non-responder MG patients of the Israeli population (n = 33), confirming a role for miR-323b-3p, -409-3p, -485-3p, -181d-5p and -340-3p as biomarkers of drug efficacy. Gene Ontology enrichment analysis, mRNA target prediction, and in silico modeling for function of the identified miRNAs disclosed functional involvement of the five miRNAs, and their putative target genes, in both immune (i.e. neurotrophin TRK and Fc-epsilon receptor signaling pathways) and drug metabolism processes. Our overall findings thus revealed a blood "miR-323b-3p, -409-3p, -485-3p, -181d-5p, and -340-3p" signature associated with drug responsiveness in MG patients. Its identification sets the basis for precision medicine approaches based on "pharmacomiRs" as biomarkers of drug responsiveness in MG, promising to improve therapeutic success in a cost/effective manner.

Upregulation of MicroRNA-128 in the Peripheral Blood of Acute Ischemic Stroke Patients is Correlated with Stroke Severity Partially through Inhibition of Neuronal Cell Cycle Reentry

MiR-128, one of the most enriched miRNAs in the human brain, has been reported to protect MCAO mice via inhibiting P38α MAPK. Whether it is involved in pathogenesis in acute ischemic stroke patients remains to be determined. The present study focused on the clinical importance of miR-128 and its underlying mechanisms. We detected miR-128 levels in the circulating lymphocytes, neutrophils, and plasma of acute ischemic stroke patients by using RT-PCR. miR-128 levels were significantly elevated in circulating lymphocytes, neutrophils, and plasma of patients with acute ischemic stroke. In addition, miR-128 levels in circulating lymphocytes correlated positively with the infarction volume, NIHSS scores at 7 days and mRS at 90 days after ischemic stroke onset. Subsequent KEGG pathway analysis showed that the MAPK signaling pathway and cell cycle are among the pathways targeted by miR-128. Although no correlation was found between miR-128 in plasma and peripheral inflammatory cell numbers, miR-128 decreased in the penumbra and increased in the infarction core of ipsilateral brain tissues in MCAO mice. Moreover, an in vitro study demonstrated that miR-128 antagomir aggravated primary neuronal damage and exacerbated cell cycle reactivation induced by OGD/R stimulation; the underlying mechanism involved increasing cyclin A2, PTEN, and ERK expression and promoting phosphorylation of PTEN and ERK. From the above results, we concluded that the upregulation of miR-128 in circulating lymphocytes of acute ischemic stroke patients was correlated with stroke severity and miR-128 antagomir exacerbated ischemia-reperfusion induced neuronal injury via promoting neuronal cell cycle reentry.

miR-128b Promotes Cerebral Infarction by Regulating the Expressions of BCL-2 and CAPASE3

OBJECTIVE

To investigate the effect of miR-128b on apoptosis and BCL-2 and CAPASE3 expression in a rat middle cerebral artery occlusion (MCAO) model.

METHODS

The MCAO model was established by the thread embolism method. miR-128b agomir and antagomir were injected into the ventricle of MCAO rats by stereotaxic intracerebral injection. Then the rats were divided into a sham group, model group, miR-128b agomir group, and miR-128b antagomir group. Zea Longa was used to score the modeling rats. The area of cerebral infarction was assessed by 2,3,5-triphenyltetrazolium chloride staining. Apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. The miR-128b relative expression was detected by real-time polymerase chain reaction. The expressions of BCL-2 and CAPASE3 were detected by immunohistochemistry and Western blotting.

RESULTS

The MCAO model was constructed successfully. The expressions of miR-128b in the MCAO groups were higher than that of the sham group (P < 0.05). Compared with the model group, the cerebral infarction area in the miR-128b agomir group was significantly bigger and that of the miR-128b antagomir group was smaller (P < 0.05). The number of apoptotic cells in the miR-128b agomir group was more and that of miR-128b antagomir group was less (P < 0.05 vs. model group). The BCL-2 expression reduced and CAPASE3 expression increased in the MCAO groups (P < 0.05 vs. sham group). Compared with the model group, the Bcl-2 expression decreased and Caspase 3 expression increased in the miR-128b agomir group, and those in the miR-128b antagomir group were opposite.

CONCLUSIONS

miR-128b promoted cerebral infarction in MCAO rats by regulating Bcl-2 and Caspase 3 expression.

Inhibition of miR-128 Abates Aβ-Mediated Cytotoxicity by Targeting PPAR-γ via NF-κB Inactivation in Primary Mouse Cortical Neurons and Neuro2a Cells

PURPOSE

Alzheimer's disease (AD) is the sixth most common cause of death in the United States. MicroRNAs have been identified as vital players in neurodegenerative diseases, including AD. microRNA-128 (miR-128) has been shown to be dysregulated in AD. This study aimed to explore the roles and molecular mechanisms of miR-128 in AD progression.

MATERIALS AND METHODS

Expression patterns of miR-128 and peroxisome proliferator-activated receptor gamma (PPAR-γ) messenger RNA in clinical samples and cells were measured using RT-qPCR assay. PPAR-γ protein levels were determined by Western blot assay. Cell viability was determined by MTT assay. Cell apoptotic rate was detected by flow cytometry via double-staining of Annexin V-FITC/PI. Caspase 3 and NF-κB activity was determined by a Caspase 3 Activity Assay Kit or NF-κB p65 Transcription Factor Assay Kit, respectively. Bioinformatics prediction and luciferase reporter assay were used to investigate interactions between miR-128 and PPAR-γ 3'UTR.

RESULTS

MiR-128 expression was upregulated and PPAR-γ expression was downregulated in plasma from AD patients and amyloid-β (Aβ)-treated primary mouse cortical neurons (MCN) and Neuro2a (N2a) cells. Inhibition of miR-128 decreased Aβ-mediated cytotoxicity through inactivation of NF-κB in MCN and N2a cells. Moreover, PPAR-γ was a target of miR-128. PPAR-γ upregulation attenuated Aβ-mediated cytotoxicity by inactivating NF-κB in MCN and N2a cells. Furthermore, PPAR-γ downregulation was able to abolish the effect of anti-miR-128 on cytotoxicity and NF-κB activity in MCN and N2a cells.

CONCLUSION

MiR-128 inhibitor decreased Aβ-mediated cytotoxicity by upregulating PPAR-γ via inactivation of NF-κB in MCN and N2a cells, providing a new potential target in AD treatment.

Up-regulation of protective neuronal MicroRNAs by FTY720 and novel FTY720-derivatives

In searching for Parkinson's disease (PD) pharmacotherapies we began studying FTY720, a food and drug administration (FDA) approved drug. We also created derivatives, FTY720-C2 and FTY720-Mitoxy, and began assessing them. Here we treated dopaminergic MN9D cells with FTY720s then measured microRNA (miRNA) levels by PCR arrays. We discovered that all three FTY720s increased miR376b-3p, while FTY720-C2 also increased miR-128-3p, miR-146b-5p, miR-7a-5p, and miR-9-5p, and FTY720-Mitoxy also increased miR-30d-5p. Investigations revealed that some miRNAs downregulate alpha-synuclein, while others reduce apoptosis, suggesting that FTY720s may act to reduce synucleinopathy and dopaminergic neuron loss in PD and related disorders.

Angiogenic miRNAs, the angiopoietin axis and related TIE2-expressing monocytes affect outcomes in cholangiocarcinoma

Background

Tumour angiogenesis is modulated on both an epigenetic and protein level and has potential implications for immune cell responses. However, the importance of related angiogenic biomarkers in cholangiocarcinoma (CCA) is unknown. This study assessed human CCA samples for the expression of angiogenesis-associated microRNAs, angiopoietins (Angs) and monocytes expressing the Ang-receptor, TIE2, with regards to prognostic significance after liver resection.

Methods

Angiogenic miRNAs were analysed in frozen samples of intrahepatic CCA (iCC; n = 43) and hilar CCA (HC; n = 45). Ang-1 and Ang-2, as well as TIE2-expressing monocytes (TEMs), were detected in paraffin-embedded iCC sections (n = 88). MiRNA expression and the abundance of TEMs and Angs were correlated with clinicopathological characteristics and survival.

Results

MiR-126 was downregulated in 76.7% of all CCA samples, with high relative expression associated with smaller tumours and reduced lymph node metastasis. High Ang-1 expression was associated with less lymphangiosis carcinomatosa and better histological grading (all p < 0.05). The absence of TEMs in iCC correlated with elevated CA19-9 levels. High relative miR-126 and low miR-128 levels were associated with improved survival in iCC and HC, respectively (all p < 0.05). High miR-126, low miR-128 and TEMs were independent prognostic factors for recurrence-free and overall survival (all p < 0.05).

Conclusions

These results suggest that angiogenic miRNAs, Angs and TEMs are of prognostic value in CCA. In addition to the possible functional links between angiogenic miRNA expression profiles, Angs and immune-cell responses by TEMs, these data have clinical implications as novel diagnostic tools.

CRISPR/Cas9 nickase mediated targeting of urokinase receptor gene inhibits neuroblastoma cell proliferation

Neuroblastoma is a tumor arising from pluripotent sympathoadrenal precursor cells of neural cell origin. Neuroblastoma is one of the most aggressive childhood tumors with highly invasive and metastatic potential. The increased expression of urokinase and its receptor is often associated with a negative prognosis in neuroblastoma patients.

We have shown that targeting of the Plaur gene in mouse neuroblastoma Neuro 2A cells by CRISPR/Cas9n results in ~60% decrease in cell proliferation (p<0.05), reduction in the number of Ki-67 positive cells, caspase 3 activation and PARP-1 cleavage. Knockout of uPAR leads to downregulation of mRNA encoding full-length TrkC receptor, which is involved in p38^MAPK and Akt signalling pathways. This finding provides a rationale to study a role of uPAR in neuroblastoma progression, since uPAR could be considered a potential therapeutic target in neuroblastoma treatment.

Exosomal small RNA sequencing uncovers the microRNA dose markers for power frequency electromagnetic field exposure

PURPOSE

The potential health risks caused by power frequency electromagnetic field (PFEMF) have led to increase public health concerns. However, the diagnosis and prognosis remain challenging in determination of exact dose of PFEMF exposure.

MATERIALS AND METHODS

Mice were exposed to different magnetic doses of PFEMF for the following isolation of serum exosomes, microRNAs (miRNAs) extraction and small RNA sequencing. After small RNA sequencing, bioinformatic analysis, quantitative real-time PCR (qRT-PCR) validation and serum exosomal miRNA biomarkers were determined.

RESULTS

Significantly changed serum exosomal miRNA as biomarkers of 0.1, 0.5, 2.5 mT and common PFEMF exposure were confirmed. Gene ontology (GO) and Kyoto encyclopaedia of genes and genomes (KEGG) pathway analysis of the downstream target genes of the above-identified exosomal miRNA markers indicated that, exosomal miRNA markers were predicted to be involved in critical pathophysiological processes of neural system and cancer- or other disease-related signalling pathways.

CONCLUSIONS

Aberrantly-expressed serum exosomal miRNAs, including miR-128-3p for 0.1 mT, miR-133a-3p for 0.5 mT, miR-142a-5p for 2.5 mT, miR-218-5p and miR-199a-3p for common PFEMF exposure, suggested a series of informative markers for not only identifying the exact dose of PFEMF exposure, also consolidating the base for future clinical intervention.

CXCR4/RhoA signaling pathway is involved in miR-128-regulated proliferation and apoptosis of human thyroid cancer cells

microRNA-128 (miR-128), a kind of short, noncoding RNAs, functioned as a tumor marker. However, the underlying function and mechanism of miR-128 in human thyroid cancer were uncertain. Therefore, in the present study, the effects of miR-128 on the proliferation and apoptosis of cultured human thyroid cancer cells were investigated. After slicing miR-128 in human thyroid cancer cells, the proliferation was measured by methyl thiazolyl tetrazolium (MTT) method, the expression of miR-128, CCAAT/enhancer binding protein-α (C/EBPα), peroxisome proliferator-activated receptor-γ (PPARγ), Caspase-3 and Caspase-9 was determined by RT-PCR, and protein expression of chemokine receptor 4 (CXCR4) and Ras homolog gene family, member A (RhoA) was analyzed by Western blot. It was found that knockdown of miR-128 promoted the optical density (OD) value of cells, enhanced mRNA expression of PPARγ and C/EBPα, while inhibited cell apoptotic rate, and Caspase-3, Caspase-9 expression. Furthermore, higher protein expression of CXCR4 and RhoA was found in the absence of miR-128. Notably, miRNA-128 over-expression-inhibited proliferation and induced-apoptosis of human thyroid cancer cells were partially changed following the block of CXCR4/RhoA signaling pathway by the CXCR4 inhibitor (AMD3100). It was indicated that miR-128 down-regulated proliferation while promoted apoptosis of human thyroid cancer cells through suppression of CXCR4/RhoA signaling pathway.

miRNA Enriched in Human Neuroblast Nuclei Bind the MAZ Transcription Factor and Their Precursors Contain the MAZ Consensus Motif

While the cytoplasmic function of microRNA (miRNA) as post-transcriptional regulators of mRNA has been the subject of significant research effort, their activity in the nucleus is less well characterized. Here we use a human neuronal cell model to show that some mature miRNA are preferentially enriched in the nucleus. These molecules were predominantly primate-specific and contained a sequence motif with homology to the consensus MAZ transcription factor binding element. Precursor miRNA containing this motif were shown to have affinity for MAZ protein in nuclear extract. We then used Ago1/2 RIP-Seq to explore nuclear miRNA-associated mRNA targets. Interestingly, the genes for Ago2-associated transcripts were also significantly enriched with MAZ binding sites and neural function, whereas Ago1-transcripts were associated with general metabolic processes and localized with SC35 spliceosomes. These findings suggest the MAZ transcription factor is associated with miRNA in the nucleus and may influence the regulation of neuronal development through Ago2-associated miRNA induced silencing complexes. The MAZ transcription factor may therefore be important for organizing higher order integration of transcriptional and post-transcriptional processes in primate neurons.

miR-151-3p Targets TWIST1 to Repress Migration of Human Breast Cancer Cells

TWIST1 is a highly conserved basic helix-loop-helix transcription factor that contributes to cancer metastasis by promoting an epithelial-mesenchymal transition and repressing E-cadherin gene expression in breast cancer. In this study, we explored the potential role of miR-151 in TWIST1 expression and cancer properties in human breast cancer cells. We found that the human TWIST1 3’UTR contains a potential binging site for miR-151-3p at the putative target sequence 5’-CAGUCUAG-3’. Using a TWIST1-3’UTR luciferase reporter assay, we demonstrated that the target sequence within the TWIST1 3’UTR is required for miR-151-3p regulation of TWIST1 expression. Moreover, we found that ectopic expression of miR-151-3p by infection with adenoviruses expressing miR-151 significantly decreased TWIST1 expression, migration and invasion, but did not affect cell growth and tumorsphere formation of human breast cancer cells. In addition, overexpression of the protein coding region without the 3’UTR of TWIST1 reversed the repression of cell migration by miR-151-3p. Furthermore, knockdown of miR-151-3p increased TWIST1 expression, reduced E-cadherin expression, and enhanced cell migration. In conclusion, these results suggest that miR-151-3p directly regulates TWIST1 expression by targeting the TWIST1 3’UTR and thus repressing the migration and invasion of human breast cancer cells by enhancing E-cadherin expression. Our findings add to accumulating evidence that microRNAs are involved in breast cancer progression by modulating TWIST1 expression.

In Silico Characterization of miRNA and Long Non-Coding RNA Interplay in Multiple Myeloma

The identification of deregulated microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in multiple myeloma (MM) has progressively added a further level of complexity to MM biology. In addition, the cross-regulation between lncRNAs and miRNAs has begun to emerge, and theoretical and experimental studies have demonstrated the competing endogenous RNA (ceRNA) activity of lncRNAs as natural miRNA decoys in pathophysiological conditions, including cancer. Currently, information concerning lncRNA and miRNA interplay in MM is virtually absent. Herein, we investigated in silico the lncRNA and miRNA relationship in a representative datasets encompassing 95 MM and 30 plasma cell leukemia patients at diagnosis and in four normal controls, whose expression profiles were generated by a custom annotation pipeline to detect specific lncRNAs. We applied target prediction analysis based on miRanda and RNA22 algorithms to 235 lncRNAs and 459 miRNAs selected with a potential pivotal role in the pathology of MM. Among pairs that showed a significant correlation between lncRNA and miRNA expression levels, we identified 11 lncRNA-miRNA relationships suggestive of a novel ceRNA network with relevance in MM.

MiR-31 and miR-128 regulates poliovirus receptor-related 4 mediated measles virus infectivity in tumors

Oncolytic measles virus strains are currently being evaluated in several clinical trials, as a promising novel oncolytic platform. Poliovirus receptor-related 4 (PVRL4) was recently identified as a potent measles virus (MV) receptor; however, its regulation is not yet understood. Increased levels of PVRL4 protein were observed in cell membrane, cytoplasm and nuclei of glioblastoma, breast and ovarian tumor clinical samples with no significant change in PVRL4 mRNA levels in glioblastoma and breast cancer compared with their corresponding control samples, suggesting that PVRL4 is likely post-transcriptionally regulated. Therefore, we sought to investigate the potential role of miRNAs in PVRL4 regulation and thus MV infectivity. We demonstrated that miR-31 and miR-128 can bind to the 3'UTR of PVRL4 and decrease PVRL4 levels while anti-miR-31/128 increase PVRL4 levels suggesting that PVRL4 is miRNA targeted. Furthermore, miR-31/128 expression levels were down-regulated in glioblastoma and breast tumor samples and showed significant negative correlations with PVRL4 levels. Infection with an MV strain that exclusively utilizes PVRL4 as its receptor showed that over-expression of miR-31/128 decreases MV infectivity while inhibition of the respective miRNAs via anti-miRs increase MV infectivity and reduce tumor size in mouse xenograft models of glioblastoma, breast and ovarian cancer. Additionally, miR-128 levels showed significant correlations with MV infection and in vivo anti-tumor effect, while MV infection increased miR-31 expression and thereby contributed to the observed decrease in PVRL4 levels. This study suggests that PVRL4 is post-transcriptionally regulated by miR-128 and miR-31 and harbors possible miRNA targets that could modulate MV infectivity and in turn enhance MV based oncolytic therapeutic strategies.

The Paradoxical Signals of Two TrkC Receptor Isoforms Supports a Rationale for Novel Therapeutic Strategies in ALS

Full length TrkC (TrkC-FL) is a receptor tyrosine kinase whose mRNA can be spliced to a truncated TrkC.T1 isoform lacking the kinase domain. Neurotrophin-3 (NT-3) activates TrkC-FL to maintain motor neuron health and function and TrkC.T1 to produce neurotoxic TNF-α; hence resulting in opposing pathways. In mouse and human ALS spinal cord, the reduction of miR-128 that destabilizes TrkC.T1 mRNA results in up-regulated TrkC.T1 and TNF-α in astrocytes. We exploited conformational differences to develop an agonistic mAb 2B7 that selectively activates TrkC-FL, to circumvent TrkC.T1 activation. In mouse ALS, 2B7 activates spinal cord TrkC-FL signals, improves spinal cord motor neuron phenotype and function, and significantly prolongs life-span. Our results elucidate biological paradoxes of receptor isoforms and their role in disease progression, validate the concept of selectively targeting conformational epitopes in naturally occurring isoforms, and may guide the development of pro-neuroprotective (TrkC-FL) and anti-neurotoxic (TrkC.T1) therapeutic strategies.

MicroRNA Genetic Variation: From Population Analysis to Functional Implications of Three Allele Variants Associated with Cancer

Nucleotide variants in microRNA regions have been associated with disease; nevertheless, few studies still have addressed the allele-dependent effect of these changes. We studied microRNA genetic variation in human populations and found that while low-frequency variants accumulate indistinctly in microRNA regions, the mature and seed regions tend to be depleted of high-frequency variants, probably as a result of purifying selection. Comparison of pairwise population fixation indexes among regions showed that the seed had higher population fixation indexes than the other regions, suggesting the existence of local adaptation in the seed region. We further performed functional studies of three microRNA variants associated with cancer (rs2910164:C > G in MIR146A, rs11614913:C > T in MIR196A2, and rs3746444:A > G in both MIR499A and MIR499B). We found differences in the expression between alleles and in the regulation of several genes involved in cancer, such as TP53, KIT, CDH1, CLH, and TERT, which may result in changes in regulatory networks related to tumorigenesis. Furthermore, luciferase-based assays showed that MIR499A could be regulating the cadherin CDH1 and the cell adhesion molecule CLH1 in an allele-dependent fashion. A better understanding of the effect of microRNA variants associated with disease could be key in our way to a more personalized medicine.

An overview of circulating cell-free microRNAs as putative biomarkers in Alzheimer's and Parkinson's Diseases

Circulating cell-free microRNAs (miRNAs) are stable in many biological fluids and their expression profiles can suffer changes under different physiological and pathological conditions. In the last few years, miRNAs have been proposed as putative noninvasive biomarkers in diagnosis, prognosis and response to treatment for several diseases, including neurodegenerative disorders as Alzheimer's disease (AD) and Parkinson's disease (PD). Cognitive and/or motor impairments are usually considered for establishing clinical diagnosis, and at this stage, the majority of the neurons may already be lost making difficult attempts of novel therapies. In this review, we intend to survey the circulating cell-free miRNAs found as dysregulated in cerebrospinal fluid, serum and plasma samples in AD and PD patients, and show how those miRNAs can be useful for early and differential diagnosis. Beyond that, we highlighted the miRNAs that are possibly related to common molecular mechanisms in the neurodegeneration process, as well those miRNAs related to specific disease pathways.

Altered hippocampal microRNA expression profiles in neonatal rats caused by sevoflurane anesthesia: MicroRNA profiling and bioinformatics target analysis

Although accumulating evidence has suggested that microRNAs (miRNAs) have a serious impact on cognitive function and are associated with the etiology of several neuropsychiatric disorders, their expression in sevoflurane-induced neurotoxicity in the developing brain has not been characterized. In the present study, the miRNAs expression pattern in neonatal hippocampus samples (24 h after sevoflurane exposure) was investigated and 9 miRNAs were selected, which were associated with brain development and cognition in order to perform a bioinformatic analysis. Previous microfluidic chip assay had detected 29 upregulated and 24 downregulated miRNAs in the neonatal rat hippocampus, of which 7 selected deregulated miRNAs were identified by the quantitative polymerase chain reaction. A total of 85 targets of selected deregulated miRNAs were analyzed using bioinformatics and the main enriched metabolic pathways, mitogen-activated protein kinase and Wnt pathways may have been involved in molecular mechanisms with regard to neuronal cell body, dendrite and synapse. The observations of the present study provided a novel understanding regarding the regulatory mechanism of miRNAs underlying sevoflurane-induced neurotoxicity, therefore benefitting the improvement of the prevention and treatment strategies of volatile anesthetics related neurotoxicity.

Interferon-β Inhibits Neurotrophin 3 Signalling and Pro-Survival Activity by Upregulating the Expression of Truncated TrkC-T1 Receptor

Although clinically useful for the treatment of various diseases, type I interferons (IFNs) have been implicated as causative factors of a number of neuroinflammatory disorders characterized by neuronal damage and altered CNS functions. As neurotrophin 3 (NT3) plays a critical role in neuroprotection, we examined the effects of IFN-β on the signalling and functional activity of the NT3/TrkC system. We found that prolonged exposure of differentiated human SH-SY5Y neuroblastoma cells to IFN-β impaired the ability of NT3 to induce transphosphorylation of the full-length TrkC receptor (TrkC-FL) and the phosphorylation of downstream signalling molecules, including PLCγ1, Akt, GSK-3β and ERK1/2. NT3 was effective in protecting the cells against apoptosis triggered by serum withdrawal or thapsigargin but not IFN-β. Prolonged exposure to the cytokine had little effects on TrkC-FL levels but markedly enhanced the messenger RNA (mRNA) and protein levels of the truncated isoform TrkC-T1, a dominant-negative receptor that inhibits TrkC-FL activity. Cell depletion of TrkC-T1 by small interfering RNA (siRNA) treatment enhanced NT3 signalling through TrkC-FL and allowed the neurotrophin to counteract IFN-β-induced apoptosis. Furthermore, the upregulation of TrkC-T1 by IFN-β was associated with the inhibition of NT3-induced recruitment of the scaffold protein tamalin to TrkC-T1 and tamalin tyrosine phosphorylation. These data indicate that IFN-β exerts a negative control on NT3 pro-survival signalling through a novel mechanism involving the upregulation of TrkC-T1.

miR-128 downregulation promotes growth and metastasis of bladder cancer cells and involves VEGF-C upregulation

MicroRNA-128 (miR-128) serves an important role in regulating growth, invasiveness, stem cell-like traits, differentiation and apoptosis of different types of tumor cells. Vascular endothelial growth factor-C (VEGF-C) has been associated with angiogenesis, lymphangiogenesis and regional lymph node metastasis and has previously been reported to have an anti-apoptotic and proliferative role in bladder cancer (BC). To investigate the regulation of miR-128 on VEGF-C expression and their effects on proliferation and metastasis of bladder cancer, T24 and 5637 BC cells were transfected with pre-miR-128, anti-miR-128 and their respective negative control. miR-128 was downregulated in BC tissues and cell lines, while the expression levels of VEGF-C were upregulated. The present results indicated that miR-128 negatively regulated VEGF-C expression in BC T24 and 5637 BC cells. VEGF-C is a direct target of miR-128 in BC cells. Overexpression of miR-128 inhibited cell proliferation, migration and invasion. Knockdown of miR-128 promoted proliferation, migration and invasion in BC cells. Therefore, downregulation mediated malignant progression of BC may be partly attributed to increased VEGF-C expression. Consequently, the findings of the present study provide a molecular basis for the role of miR-128/VEGF-C in the progression of human BC and indicate a novel target for treatment of BC.

Chemoresistance, cancer stem cells, and miRNA influences: the case for neuroblastoma

Neuroblastoma is a type of cancer that develops most often in infants and children under the age of five years. Neuroblastoma originates within the peripheral sympathetic ganglia, with 30% of the cases developing within the adrenal medulla, although it can also occur within other regions of the body such as nerve tissue in the spinal cord, neck, chest, abdomen, and pelvis. MicroRNAs (miRNAs) regulate cellular pathways, differentiation, apoptosis, and stem cell maintenance. Such miRNAs regulate genes involved in cellular processes. Consequently, they are implicated in the regulation of a spectrum of signaling pathways within the cell. In essence, the role of miRNAs in the development of cancer is of utmost importance for the understanding of dysfunctional cellular pathways that lead to the conversion of normal cells into cancer cells. This review focuses on highlighting the recent, important implications of miRNAs within the context of neuroblastoma basic research efforts, particularly concerning miRNA influences on cancer stem cell pathology and chemoresistance pathology for this condition, together with development of translational medicine approaches for novel diagnostic tools and therapies for this neuroblastoma.

Prognostic implications of tissue and serum levels of microRNA-128 in human prostate cancer

BACKGROUND AND PURPOSE

MicroRNA-128 (miR-128) has been identified as a negative regulator of malignant phenotypes of prostate cancer (PCa) cells. The aim of this study was to evaluate the prognostic implications of both tissue and serum levels of miR-128 expression in PCa patients undergoing radical prostatectomy.

METHODS

A series of 128 cases with PCa were evaluated for both tissue and serum levels of miR-128 expression by quantitative reverse-transcription PCR.

RESULTS

Compared with non-cancerous prostate tissues and normal sera, both tissue and serum levels of miR-128 expression were significantly decreased in PCa patients (both P<0.001). Importantly, there was a close correlation between tissue and serum levels of miR-128 expression in PCa patients (rs=0.808, P<0.001). Then, low miR-128 expression in both PCa tissues and patients' sera were dramatically associated with aggressive clinicopathological features, including advanced pathological stage (both P=0.001), positive lymph node metastasis (P=0.006 and 0.01, respectively), high preoperative PSA (both P=0.01) and positive angiolymphatic invasion (both P=0.02). Moreover, Kaplan-Meier survival analysis showed that low miR-128 expression in both PCa tissues and patients' sera were significantly associated with short biochemical recurrence (BCR)-free survival. Furthermore, multivariate analysis indicated that both tissue and serum levels of miR-128 expression were independent prognostic factors for BCR-free survival of PCa patients.

CONCLUSION

Our data suggest that the decreased expression of miR-128 in both tissue and serum samples of PCa patients may be associated with tumor malignant progression and BCR-free survival. Particularly, serum miR-128 may be developed as a novel noninvasive biomarker for PCa diagnosis and prognosis.

Regulatory networks between neurotrophins and miRNAs in brain diseases and cancers

Neurotrophins are involved in many physiological and pathological processes in the nervous system. They regulate and modify signal transduction, transcription and translation in neurons. It is recently demonstrated that the neurotrophin expression is regulated by microRNAs (miRNAs), changing our views on neurotrophins and miRNAs. Generally, miRNAs regulate neurotrophins and their receptors in at least two ways: (1) miRNAs bind directly to the 3′ untranslated region (UTR) of isoform-specific mRNAs and post-transcriptionally regulate their expression; (2) miRNAs bind to the 3′ UTR of the regulatory factors of neurotrophins and regulate their expression. On the other hand, neurotrophins can regulate miRNAs. The results of BNDF research show that neurotrophins regulate miRNAs in at least three ways: (1) ERK stimulation enhances the activation of TRBP (HIV-1 TAR RNA-binding protein) and Dicer, leading to the upregulation of miRNA biogenesis; (2) ERK-dependent upregulation of Lin28a (RNA-binding proteins) blocks select miRNA biogenesis; (3) transcriptional regulation of miRNA expression through activation of transcription factors, including CREB and NF-κB. These regulatory processes integrate positive and negative regulatory loops in neurotrophin and miRNA signaling pathways, and also expand the function of neurotrophins and miRNAs. In this review, we summarize the current knowledge of the regulatory networks between neurotrophins and miRNAs in brain diseases and cancers, for which novel cutting edge therapeutic, delivery and diagnostic approaches are emerging.

miR-20a promotes prostate cancer invasion and migration through targeting ABL2

The aberrant expression of microRNAs (miRNAs) has been found in various types of cancer. The present study found miR-20a was significantly up-regulated in prostate cancer compared with normal prostate tissues. Patients with a higher miR-20a expression had a Gleason score of 7-10 and shorter survival time. The transwell and wound healing assays revealed that blocking expression of miR-20a by miR-20a ASO suppresses the invasion and migration of PC-3 and DU145 cells in vitro and also inhibits tumor growth in vivo. Furthermore, we identified miR-20a directly targets the ABL family non-receptor tyrosine kinases ABL2 and negatively regulates the phosphorylation of its downstream gene p190RhoGAP. Knockdown of ABL2 promoted cell invasion and migration and we identified miR-20a-induced cell invasion and migration can be rescued by ABL2. In conclusion, our findings show that miR-20a significantly contributes to the progression of prostate cancer by targeting ABL2.

microRNAs and Neurodegenerative Diseases

microRNAs (miRNAs) are small, noncoding RNA molecules that through imperfect base-pairing with complementary sequences of target mRNA molecules, typically cleave target mRNA, causing subsequent degradation or translation inhibition. Although an increasing number of studies have identified misregulated miRNAs in the neurodegenerative diseases (NDDs) Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis, which suggests that alterations in the miRNA regulatory pathway could contribute to disease pathogenesis, the molecular mechanisms underlying the pathological implications of misregulated miRNA expression and the regulation of the key genes involved in NDDs remain largely unknown. In this chapter, we provide evidence of the function and regulation of miRNAs and their association with the neurological events in NDDs. This will help improve our understanding of how miRNAs govern the biological functions of key pathogenic genes in these diseases, which potentially regulate several pathways involved in the progression of neurodegeneration. Additionally, given the growing interest in the therapeutic potential of miRNAs, we discuss current clinical challenges to developing miRNA-based therapeutics for NDDs.

Regulation of a TrkB Alternative Transcript by microRNAs

Background/Aims

Tropomyosin-related kinase B receptor (TrkB)-mediated signaling is vital for neuronal differentiation, survival, plasticity, and cognition. In this study, the focus was placed on TrkB-Shc, a neuron-specific transcript, to determine if microRNAs (miRNAs) play a role in TrkB-Shc regulation.

Methods

A combination of bioinformatics and molecular gene expression analysis techniques was used to assess the effect of miR-409-3p and miR-216b on TrkB-Shc expression.

Results

miR-409-3p and miR-216b were found to regulate the TrkB-Shc 3′UTR through the identified putative binding sites. When the effect of the miRNAs on TrkB was assessed using SHSY5Y neuronal cells, differential effects were observed between mRNA and protein expression.

Conclusion

This study highlights the importance of miRNA-mediated regulation in TrkB signaling.

microRNA-128a dysregulation in transgenic Huntington's disease monkeys

BACKGROUND

Huntington's Disease (HD) is a progressive neurodegenerative disorder with a single causal mutation in the Huntingtin (HTT) gene. MicroRNAs (miRNAs) have recently been implicated as epigenetic regulators of neurological disorders, however, their role in HD pathogenesis is not well defined. Here we study transgenic HD monkeys (HD monkeys) to examine miRNA dysregulation in a primate model of the disease.

RESULTS

In this report, 11 miRNAs were found to be significantly associated (P value < 0.05) with HD in the frontal cortex of the HD monkeys. We further focused on one of those candidates, miR-128a, due to the corresponding disruption in humans and mice with HD as well as its intriguing lists of gene targets. miR-128a was downregulated in our HD monkey model by the time of birth. We then confirmed that miR-128a was also downregulated in the brains of pre-symptomatic and post-symptomatic HD patients. Additionally, our studies confirmed a panel of canonical HD signaling genes regulated by miR-128a, including HTT and Huntingtin Interaction Protein 1 (HIP1).

CONCLUSION

Our studies found that miR-128a may play a critical role in HD and could be a viable candidate as a therapeutic or biomarker of the disease.

miRNA-199a-5p regulates VEGFA in endometrial mesenchymal stem cells and contributes to the pathogenesis of endometriosis

It is believed that endometrial miRNAs contribute to the aetiology of endometriosis in stem cells; however, the mechanisms remain unclear. Here we collected serum samples from patients with or without endometriosis and characterized the miRNA expression profiles of these two groups. MicroRNA-199a-5p (miR-199a-5p) was dramatically down-regulated in patients with endometriosis compared with control patients. In addition, we found that the tumour suppressor gene, SMAD4, could elevate miR-199a-5p expression in ectopic endometrial mesenchymal stem cells. Up-regulation of miR-199a-5p suppressed cell proliferation, motility and angiogenesis of these ectopic stem cells by targeting the 3' untranslated region of VEGFA. Furthermore, we established an animal model of endometriosis and found that miR-199a-5p could decrease the size of endometriotic lesions in vivo. Taken together, this newly identified miR-199a-5p module provides a new avenue to the understanding of the processes of endometriosis development, especially proliferation, motility and angiogenesis, and may facilitate the development of potential therapeutics against endometriosis.

Peripherally restricted acute phase response to a viral mimic alters hippocampal gene expression

We have previously shown that peripherally restricted acute phase response (APR) elicited by intraperitoneal (i.p.) injection of a viral mimic, polyinosinic-polycytidylic acid (PIC), renders the brain hypersusceptible to excitotoxic insult as seen from profoundly exacerbated kainic acid (KA)-induced seizures. In the present study, we found that this hypersusceptibility was protracted for up to 72 h. RT-PCR profiling of hippocampal gene expression revealed rapid upregulation of 23 genes encoding cytokines, chemokines and chemokine receptors generally within 6 h after PIC challenge. The expression of most of these genes decreased by 24 h. However, two chemokine genes, i.e., Ccl19 and Cxcl13 genes, as well as two chemokine receptor genes, Ccr1 and Ccr7, remained upregulated for 72 h suggesting their possible involvement in the induction and sustenance of seizure hypersusceptibility. Also, 12 genes encoding proteins related to glutamatergic and GABAergic neurotransmission featured initial upregulation or downregulation followed by gradual normalization. The upregulation of the Gabrr3 gene remained upregulated at 72 h, congruent with its plausible role in the hypersusceptible phenotype. Moreover, the expression of ten microRNAs (miRs) was rapidly affected by PIC challenge, but their levels generally exhibited oscillating profiles over the time course of seizure hypersusceptibility. These results indicate that protracted seizure susceptibility following peripheral APR is associated with a robust polygenic response in the hippocampus.

Brain microRNAs and insights into biological functions and therapeutic potential of brain enriched miRNA-128

MicroRNAs, the non-coding single-stranded RNA of 19–25 nucleotides are emerging as robust players of gene regulation. Plethora of evidences support that the ability of microRNAs to regulate several genes of a pathway or even multiple cross talking pathways have significant impact on a complex regulatory network and ultimately the physiological processes and diseases. Brain being a complex organ with several cell types, expresses more distinct miRNAs than any other tissues. This review aims to discuss about the microRNAs in brain development, function and their dysfunction in brain tumors. We also provide a comprehensive summary of targets of brain specific and brain enriched miRNAs that contribute to the diversity and plasticity of the brain. In particular, we uncover recent findings on miRNA-128, a brain-enriched microRNA that is induced during neuronal differentiation and whose aberrant expression has been reported in several cancers. This review describes the wide spectrum of targets of miRNA-128 that have been identified till date with potential roles in apoptosis, angiogenesis, proliferation, cholesterol metabolism, self renewal, invasion and cancer progression and how this knowledge might be exploited for the development of future miRNA-128 based therapies for the treatment of cancer as well as metabolic diseases.