MiR-30a-5p is induced by Wnt/β-catenin pathway and promotes glioma cell invasion by repressing NCAM

Fischer JDS. Proteomics reveals differentially regulated pathways when comparing grade 2 and 4 astrocytomas

Astrocytic tumors are known for their high progression capacity and high mortality rates; in this regard, proteins correlated to prognosis can aid medical conduct. Although several genetic changes related to progression from grade 2 to grade 4 astrocytoma are already known, mRNA copies do not necessarily correlate with protein abundance and therefore could shadow further comprehension about this tumor's biology. This motivates us to seek for complementary strategies to study tumor progression at the protein level. Here we compare the proteomic profile of biopsies from patients with grade 2 (diffuse, n = 6) versus grade 4 astrocytomas (glioblastomas, n = 10) using shotgun proteomics. Data analysis performed with PatternLab for proteomics identified 5,206 and 6,004 proteins in the 2- and 4-grade groups, respectively. Our results revealed seventy-four differentially abundant proteins (p < 0.01); we then shortlist those related to greater malignancy. We also describe molecular pathways distinctly activated in the two groups, such as differences in the organization of the extracellular matrix, decisive both in tumor invasiveness and in signaling for cell division, which, together with marked contrasts in energy metabolism, are determining factors in the speed of growth and dissemination of these neoplasms. The degradation pathways of GABA, enriched in the grade 2 group, is consistent with a favorable prognosis. Other functions such as platelet degranulation, apoptosis, and activation of the MAPK pathway were correlated to grade 4 tumors and, consequently, unfavorable prognoses. Our results provide an important survey of molecular pathways involved in glioma pathogenesis for these histopathological groups.

Integrating Multi-Omics Analysis for Enhanced Diagnosis and Treatment of Glioblastoma: A Comprehensive Data-Driven Approach

The most aggressive primary malignant brain tumor in adults is glioblastoma (GBM), which has poor overall survival (OS). There is a high relapse rate among patients with GBM despite maximally safe surgery, radiation therapy, temozolomide (TMZ), and aggressive treatment. Hence, there is an urgent and unmet clinical need for new approaches to managing GBM. The current study identified modules (MYC, EGFR, PIK3CA, SUZ12, and SPRK2) involved in GBM disease through the NeDRex plugin. Furthermore, hub genes were identified in a comprehensive interaction network containing 7560 proteins related to GBM disease and 3860 proteins associated with signaling pathways involved in GBM. By integrating the results of the analyses mentioned above and again performing centrality analysis, eleven key genes involved in GBM disease were identified. ProteomicsDB and Gliovis databases were used for determining the gene expression in normal and tumor brain tissue. The NetworkAnalyst and the mGWAS-Explorer tools identified miRNAs, SNPs, and metabolites associated with these 11 genes. Moreover, a literature review of recent studies revealed other lists of metabolites related to GBM disease. The enrichment analysis of identified genes, miRNAs, and metabolites associated with GBM disease was performed using ExpressAnalyst, miEAA, and MetaboAnalyst tools. Further investigation of metabolite roles in GBM was performed using pathway, joint pathway, and network analyses. The results of this study allowed us to identify 11 genes (UBC, HDAC1, CTNNB1, TRIM28, CSNK2A1, RBBP4, TP53, APP, DAB1, PINK1, and RELN), five miRNAs (hsa-mir-221-3p, hsa-mir-30a-5p, hsa-mir-15a-5p, hsa-mir-130a-3p, and hsa-let-7b-5p), six metabolites (HDL, N6-acetyl-L-lysine, cholesterol, formate, N, N-dimethylglycine/xylose, and X2. piperidinone) and 15 distinct signaling pathways that play an indispensable role in GBM disease development. The identified top genes, miRNAs, and metabolite signatures can be targeted to establish early diagnostic methods and plan personalized GBM treatment strategies.

Identification of Serum miRNAs as Effective Diagnostic Biomarkers for Distinguishing Primary Central Nervous System Lymphoma from Glioma

Invasive surgical cerebrum biopsy results in delayed treatment for the definitive diagnosis of primary central nervous system lymphoma (PCNSL). The existent research was aimed at confirming the underlying diagnostic miRNAs of distinguishing PCNSL from glioma. A publicly available miRNA expression profiles (GSE139031) from adult PCNSL as well as glioma specimens were provided by GEO datasets. Differentially expressed miRNAs (DEMs) were filtered between 42 PCNSL patients and 170 glioma patients. Candidate miRNAs were identified through SVM-RFE analysis and LASSO model. ROC assays were operated to determine the diagnostic value of serum miRNAs in distinguishing PCNSL from glioma. StarBase v2.0 was applied to screen the targeting genes of miRNAs, and KEGG analysis was applied using the targeting genes of miRNAs. In this study, we identified 12 dysregulated miRNAs between PCNSL and glioma samples. The ten critical miRNAs (miR-6820-3p, miR-6803-3p, miR-30a-3p, miR-4751, miR-3918, miR-146a-3p, miR-548am-3p, miR-371a-3p, miR-487a-3p, and miR-4756-5p) between these two algorithms were ultimately identified. The results of KEGG revealed that the targeting genes of hsa-miR-3918 were primarily related to MAPK signal pathway, PI3K-Akt signal pathway, and human papillomavirus infection. Overall, bioinformatics analysis revealed that ten miRNAs are potential biomarker for distinguishing PCNSL from glioma.

Oncogenic Role of Exosomal Circular and Long Noncoding RNAs in Gastrointestinal Cancers

Circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) are differentially expressed in gastrointestinal cancers. These noncoding RNAs (ncRNAs) regulate a variety of cellular activities by physically interacting with microRNAs and proteins and altering their activity. It has also been suggested that exosomes encapsulate circRNAs and lncRNAs in cancer cells. Exosomes are then discharged into the extracellular environment, where they are taken up by other cells. As a result, exosomal ncRNA cargo is critical for cell-cell communication within the cancer microenvironment. Exosomal ncRNAs can regulate a range of events, such as angiogenesis, metastasis, immune evasion, drug resistance, and epithelial-to-mesenchymal transition. To set the groundwork for developing novel therapeutic strategies against gastrointestinal malignancies, a thorough understanding of circRNAs and lncRNAs is required. In this review, we discuss the function and intrinsic features of oncogenic circRNAs and lncRNAs that are enriched within exosomes.

Dysregulation of the miR-30a/BiP axis by cigarette smoking accelerates oral cancer progression

Background

Cigarette smoking is the most significant cause of oral cancer progression. Cigarette smoke condensate (CSC) has been shown to induce endoplasmic reticulum (ER) stress. Binding immunoglobulin protein (BiP) being as an ER stress regulator, has been reported to be implicated in malignant behaviors. Therefore, the aim of this study was to investigate the role of the ER stress-responsive protein, BiP, in CSC-induced oral squamous cell carcinoma (OSCC) malignancy.

Methods

The biological role of BiP in CSC-induced tumor progression was investigated in OSCC cells (YD38 and SCC25) and in a tumor xenograft mouse model. The expressions of related genes were investigated using quantitative RT-PCR and Western blot analysis. Cell migration and invasion were assessed using scratch wound healing and Transwell invasion assays. The effects of conditioned media from OSCC cells on the angiogenic activities of endothelial cells were analyzed using a tube formation assay. The interaction between miR-30a and BiP mRNA was detected using a luciferase reporter assay.

Results

Our results demonstrated that CSC increased the expression of BiP in time- and dose-dependent manners in YD38 and SCC25 cells, and that silencing BiP abrogated CSC-induced cell invasion and tumor-associated angiogenesis. Notably, the putative miR-30a binding site was observed in the 3′untranslated region (UTR) of BiP mRNA, and miR-30a suppressed BiP expression by targeting 3′UTR of BiP transcript. In addition, CSC increased the expression of BiP in OSCC cells by downregulating miR-30a. We also showed that BiP promoted invasion and tumor-associated angiogenesis by increasing the production and secretion of vascular endothelial growth factor in CSC-exposed OSCC cells. Moreover, BiP inhibition suppressed OSCC growth and reduced tumor vessel density in tumor-bearing mice administered with CSC.

Conclusions

These observations suggest that epigenetic regulation of BiP via miR-30a downregulation is involved in CSC-induced OSCC progression.

MicroRNAs: emerging driver of cancer perineural invasion

The perineural invasion (PNI), which refers to tumor cells encroaching on nerve, is a clinical feature frequently occurred in various malignant tumors, and responsible for postoperative recurrence, metastasis and decreased survival. The pathogenesis of PNI switches from 'low-resistance channel' hypothesis to 'mutual attraction' theory between peripheral nerves and tumor cells in perineural niche. Among various molecules in perineural niche, microRNA (miRNA) as an emerging modulator of PNI through generating RNA-induced silencing complex (RISC) to orchestrate oncogene and anti-oncogene has aroused a wide attention. This article systematically reviewed the role of microRNA in PNI, promising to identify new biomarkers and offer cancer therapeutic targets.

Bivalent Genes Targeting of Glioma Heterogeneity and Plasticity

Gliomas account for most primary Central Nervous System (CNS) neoplasms, characterized by high aggressiveness and low survival rates. Despite the immense research efforts, there is a small improvement in glioma survival rates, mostly attributed to their heterogeneity and complex pathophysiology. Recent data indicate the delicate interplay of genetic and epigenetic mechanisms in regulating gene expression and cell differentiation, pointing towards the pivotal role of bivalent genes. Bivalency refers to a property of chromatin to acquire more than one histone marks during the cell cycle and rapidly transition gene expression from an active to a suppressed transcriptional state. Although first identified in embryonal stem cells, bivalent genes have now been associated with tumorigenesis and cancer progression. Emerging evidence indicates the implication of bivalent gene regulation in glioma heterogeneity and plasticity, mainly involving Homeobox genes, Wingless-Type MMTV Integration Site Family Members, Hedgehog protein, and Solute Carrier Family members. These genes control a wide variety of cellular functions, including cellular differentiation during early organism development, regulation of cell growth, invasion, migration, angiogenesis, therapy resistance, and apoptosis. In this review, we discuss the implication of bivalent genes in glioma pathogenesis and their potential therapeutic targeting options.

Neural Cell Adhesion Molecule Regulates Osteoblastic Differentiation Through Wnt/β-Catenin and PI3K-Akt Signaling Pathways in MC3T3-E1 Cells

Neural cell adhesion molecule (NCAM) is involved in cell multi-directional differentiation, but its role in osteoblast differentiation is still poorly understood. In the present study, we investigated whether and how NCAM regulates osteoblastic differentiation. We found that NCAM silencing inhibited osteoblast differentiation in pre-osteoblastic MC3T3-E1 cells. The function of NCAM was further confirmed in NCAM-deficient mesenchymal stem cells (MSCs), which also had a phenotype with reduced osteoblastic potential. Moreover, NCAM silencing induced decrease of Wnt/β-catenin and Akt activation. The Wnt inhibitor blocked osteoblast differentiation, and the Wnt activator recovered osteoblast differentiation in NCAM-silenced MC3T3-E1 cells. We lastly demonstrated that osteoblast differentiation of MC3T3-E1 cells was inhibited by the PI3K-Akt inhibitor. In conclusion, these results demonstrate that NCAM silencing inhibited osteoblastic differentiation through inactivation of Wnt/β-catenin and PI3K-Akt signaling pathways.

Critical role of HOX transcript antisense intergenic RNA (HOTAIR) in gliomas

Despite extensive research, gliomas are associated with high morbidity and mortality, mainly attributed to the rapid growth rate, excessive invasiveness, and molecular heterogeneity, as well as regenerative potential of cancer stem cells. Therefore, elucidation of the underlying molecular mechanisms and the identification of potential molecular diagnostic and prognostic biomarkers are of paramount importance. HOX transcript antisense intergenic RNA (HOTAIR) is a well-studied long noncoding RNA, playing an emerging role in tumorigenesis of several human cancers. A growing amount of preclinical and clinical evidence highlights the pro-oncogenic role of HOTAIR in gliomas, mainly attributed to the enhancement of proliferation and migration, as well as inhibition of apoptosis. In vitro and in vivo studies demonstrate that HOTAIR modulates the activity of specific transcription factors, such as MXI1, E2F1, ATF5, and ASCL1, and regulates the expression of cell cycle-associated genes along with related signaling pathways, like the Wnt/β-catenin axis. Moreover, it can interact with specific miRNAs, including miR-326, miR-141, miR-148b-3p, miR-15b, and miR-126-5p. Of importance, HOTAIR has been demonstrated to enhance angiogenesis and affect the permeability of the blood-tumor barrier, thus modulating the efficacy of chemotherapeutic agents. Herein, we provide evidence on the functional role of HOTAIR in gliomas and discuss the benefits of its targeting as a novel approach toward glioma treatment.

miR-30a-3p participates in the development of asthma by targeting CCR3

This study aimed to investigate the role and relevant mechanism of miR-30a-3p action in asthma. The results of this study revealed that the expression levels of miR-30a-3p were significantly decreased in the peripheral blood of asthmatic patients. In addition, we found that the CC chemokine receptor (CCR3) was a target of miR-30a-3p. Subsequently, an asthma mouse model was established using ovalbumin (OVA). The results showed that the expression of miR-30a-3p and CCR3 was downregulated and upregulated, respectively, in the peripheral blood of asthmatic mice. Enzyme-linked immunosorbent assay (ELISA) in asthmatic mouse serum demonstrated that miR-30a-3p mimic treatment significantly decreased the secretion of OVA-specific IgE, eotaxin-1, interleukin (IL)-5, and IL-4. These results suggested that miR-30a-3p inhibited CCR3 signaling pathway and relieved the inflammatory response against asthma in vivo. Eosinophils have also been implicated in the asthmatic inflammatory response. Therefore, the in vitro effects of miR-30a-3p on eosinophil activity were determined. Findings suggested that miR-30a-3p mimic significantly reduced eosinophil viability and migration and induced apoptosis. In addition, CCR3 and eotaxin-1 downregulation were observed. The aforementioned results were significantly reversed following CCR3 overexpression. This study suggested that miR-30a-3p was involved in asthma by regulating eosinophil activity and targeting CCR3.

Identification of serum miR-30a-5p as a diagnostic and prognostic biomarker in colorectal cancer

BACKGROUND

Circulating microRNAs (miRNAs) have become increasingly appreciated in the diagnosis and prognosis of colorectal cancer (CRC).

OBJECTIVE

The aim of this study was to assess the potential diagnostic and prognostic significance of serum miR-30a-5p as a potential biomarker.

METHODS

The expression levels of serum miR-30a-5p were measured in 138 cases with CRC, 50 cases with benign lesions (colorectal adenoma and polyps) and 60 healthy volunteers by quantitative real time polymerase chain reaction (qRT-PCR).

RESULTS

The results showed that serum miR-30a-5p levels were frequently downregulated in patients with CRC and benign lesions in comparison with normal controls. Moreover, serum miR-30a-5p levels in early-stage CRC patients were significantly increased after surgery. Receiver-operating characteristic (ROC) curve analysis demonstrated serum miR-30a-5p could well distinguish CRC patients, early-stage CRC patients from healthy controls with a relative high value of area under the curve (AUC). Furthermore, low serum miR-30a-5p expression was more frequently occurred in CRC patients with aggressive clinical variables. Additionally, CRC patients exhibiting high serum miR-30a-5p expression had significantly prolonged overall survival than those exhibiting low expression. Finally, both univariate and multivariate analyses revealed that serum miR-30a-5p expression was an independent prognostic factor for overall survival in CRC patients.

CONCLUSIONS

Collectively, these findings suggested serum miR-30a-5p might act as a novel biomarker for the diagnosis and prognosis of CRC.

Comparative analysis of milk microRNA in the therian lineage highlights the evolution of lactation

Milk is a complex secretion that has an important role in mammalian reproduction. It is only recently that sequencing technologies have allowed the identification and quantification of microRNA (miRNA) in milk of a growing number of mammalian species. This provides a novel window on the study of the evolution and functionality of milk through the comparative analysis of milk miRNA content. Here, milk miRNA sequencing data from five species (one marsupial (tammar wallaby) and four eutherians (human, mouse, cow and pig)) have been retrieved from public depositories and integrated in order to perform a comparison of milk miRNA profiles. The study shows that milk miRNA composition varies widely between species, except for a few miRNAs that are ubiquitously expressed in the milk of all mammals and indicates that milk miRNA secretion has broadly evolved during mammalian evolution. The putative functions of the most abundant milk miRNAs are also discussed.

Trichostatin A‑induced miR‑30a‑5p regulates apoptosis and proliferation of keloid fibroblasts via targeting BCL2

Keloids are benign fibrous overgrowths that occur as a result of abnormal wound healing following cutaneous injury. MicroRNAs (miRNAs/miRs) are short non-coding RNAs that serve critical roles in numerous important biological processes, such as cell proliferation, differentiation and apoptosis. However, their role in keloid development remains largely unknown. In the present study, the role of miR-30a-5p, a miRNA regulated by Trichostatin A (TSA), in apoptosis within cultured keloid fibroblasts was investigated. An MTT assay was used to detect the proliferation of cultured keloid fibroblasts treated with TSA. Cell apoptosis and cell cycle phases were analyzed using flow cytometry. In addition, an miRNA microarray was performed to compare expression profiles between cultured keloid fibroblasts treated with or without 1,000 nM TSA. Reverse transcription-quantitative polymerase chain reaction analysis was conducted to estimate miRNA expression levels. The direct target of miR-30a-5p was identified using a dual-luciferase reporter assay. Western blotting was employed to assess protein expression levels in keloid fibroblasts. The results demonstrated that TSA inhibited the proliferation of keloid fibroblasts in a time- and dose-dependent manner. The miRNA microarray revealed alterations in the expression of numerous miRNA sequences in response to TSA when compared with controls. Notably, the expression of miR-30a-5p was downregulated in keloid tissues. In addition, overexpression of miR-30a-5p induced apoptosis by targeting B-cell lymphoma 2, which was similar to that observed in response to TSA. These results provide important information regarding a novel miR-30a-5p-mediated signaling pathway induced by TSA treatment, and suggest a potential use for TSA and miR-30a-5p as effective therapeutic strategies for keloids.

A positive feedback loop of miR-30a-5p-WWP1-NF-κB in the regulation of glioma development

Previous studies demonstrated that miR-30a-5p promotes glioma cell growth and invasion. Furthermore, WWP1 (WW domain containing E3 ubiquitin protein ligase 1) inhibits NF-κB activation that is strongly correlated with gliomagenesis. Using the GEO database and bioinformatics analyses, we identified WWP1 was downregulated in glioma tissues and might be a putative target for miR-30a-5p. Hence, this study aims to explore the interaction among miR-30a-5p, WWP1, and NF-κB and their roles in the regulation of glioma development. We found decreased WWP and increased miR-30a-5p expression and p65 phosphorylation in glioma tissues. Furthermore, WWP1 mRNA level was negatively correlated with miR-30a-5p expression in glioma tissues. Interestingly, miR-30a-5p targeted WWP1 expression. Additionally, NF-κB p65 overexpression increased miR-30a-5p expression through direct binding of NF-κB RelA subunit to the promoter of miR-30a-5p. We also confirmed that WWP1 overexpression decreased phosphorylation of NF-κB p65. Importantly, miR-30a-5p promoted glioma cell proliferation, migration, and invasion via targeting WWP1. Furthermore, NF-κB p65 overexpression inhibited WWP1 expression and promoted glioma cell malignant behaviors via inducing miR-30a-5p transcription. Moreover, WWP1 overexpression decreased miR-30a-5p expression and inhibited glioma cell malignant behaviors via inhibiting NF-κB p65. Our further assay showed that WWP1 inhibited in vivo growth of xenograft tumors of glioma cells, accompanied with a decrease in miR-30-5p expression and phosphorylation of NF-κB p65. In conclusion, there is a "miR-30a-5p-WWP1-NF-κB" positive feedback loop, which plays an important role in regulating glioma development and might provide a potential therapeutic strategy for treating glioma.

Identification of a Novel Splice Variant of Neural Cell Adhesion Molecule in Glioblastoma Through Proteogenomics Analysis

Splice variants are known to be important in the pathophysiology of tumors, including the brain cancers. We applied a proteogenomics pipeline to identify splice variants in glioblastoma (GBM, grade IV glioma), a highly malignant brain tumor, using in-house generated mass spectrometric proteomic data and public domain RNASeq dataset. Our analysis led to the identification of a novel exon that maps to the long isoform of Neural cell adhesion molecule 1 (NCAM1), expressed on the surface of glial cells and neurons, important for cell adhesion and cell signaling. The presence of the novel exon is supported with the identification of five peptides spanning it. Additional peptides were also detected in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gel separated proteins from GBM patient tissue, underscoring the presence of the novel peptides in the intact brain protein. The novel exon was detected in the RNASeq dataset in 18 of 25 GBM samples and separately validated in additional 10 GBM tumor tissues using quantitative real-time-polymerase chain reaction (qRT-PCR). Both transcriptomic and proteomic data indicate downregulation of NCAM1, including the novel variant, in GBM. Domain analysis of the novel NCAM1 sequence indicates that the insertion of the novel exon contributes extra low-complexity region in the protein that may be important for protein-protein interactions and hence for cell signaling associated with tumor development. Taken together, the novel NCAM1 variant reported in this study exemplifies the importance of future multiomics research and systems biology applications in GBM.

LINC00461 promotes cell migration and invasion in breast cancer through miR-30a-5p/integrin β3 axis

Mounting evidence has demonstrated that long noncoding RNAs (lncRNAs) are dysregulated and implicated in the occurrence and development of a wide range of human malignancies. LINC00461, a novel cancer-related lncRNA, has been reported to be highly expressed and serve as oncogene in glioma; however, its biological role in breast cancer (BC) remains obscure. This study aimed to explore the role of LINC00461 in BC and elucidate the potential molecular mechanisms involved. In the current study, LINC00461 was found to be significantly upregulated in both BC tissues and cell lines. Besides, we found that high LINC00461 expression was associated with TNM stage and differentiation. Furthermore, functional studies demonstrated that LINC00461 expedited BC cell migration and invasion. Notably, LINC00461 was observed to enhance the expression of vimentin and zinc-finger E-box binding homeobox factor 1, suppress the expression of E-cadherin, and promote the activation of extracellular signal-regulated kinase and AKT signaling pathways. Mechanical investigations revealed that LINC00461 positively modulated integrin β3 (ITGB3) expression as miR-30a-5p sponge in BC cells. Taken together, LINC00461 exerts an oncogenic role in BC through miR-30a-5p/ITGB3 axis. Our data indicate that LINC00461 may be used to be a novel candidate therapeutic target and a valuable diagnostic biomarker for BC.

MicroRNA-30a suppresses the proliferation, migration and invasion of human renal cell carcinoma cells by directly targeting ADAM9

An increasing number of studies reported that microRNA (miR)-30a was dysregulated in several types of human cancer and may contribute to cancer carcinogenesis and progression. However, its expression and roles in renal cell carcinoma (RCC) remain unknown. In the present study, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to quantify miR-30a expression in RCC tissues and cell lines. The cell counting kit-8 assay, migration and invasion assays were used to evaluate the roles of miR-30a on the proliferation, migration and invasion of RCC cells. The target gene of miR-30a was identified by luciferase reporter assays, RT-qPCR and western blotting. The results indicated that miR-30a was downregulated in RCC tissues and cell lines compared with corresponding noncancerous tissues and normal renal cell line, respectively. Re-expression of miR-30a inhibited the proliferation, migration and invasion of RCC cells. Additionally, ADAM metallopeptidase domain 9 (ADAM9) was validated as a direct target of miR-30a. Furthermore, the knockdown of ADAM9 by small interfering RNAs was able to mimic the effects of miR-30a overexpression in RCC cells. These results highlight the important role for miR-30a in the occurrence and development of RCC, and the restoration of miR-30a might be investigated as a potential strategy for treating RCC.

MiR-30a: A Novel Biomarker and Potential Therapeutic Target for Cancer

MicroRNAs (miRNAs) are small, highly conserved noncoding RNAs molecules, consisting of 18–25 nucleotides that regulate gene expression by binding to complementary binding sites within the 3′untranslated region (3′UTR) of target mRNAs. MiRNAs have been involved in regulating gene expression and diverse physiological and pathological processes. Several studies have reported that miR-30a, situated on chromosome 6q.13, is produced by an intronic transcriptional unit. Moreover, miR-30a has demonstrated its role in biological processes, including inhibiting proliferation and metastasis in many tumors, autophagy in chronic myelogenous leukemia, and regulating TGF-b1-induced epithelial-mesenchymal transition. However, based on the pathogenetic relationship between miR-30a and cancer in tumorigenesis, we believe that miR-30a may serve as tumor promising biomarker. Moreover, it would offer a therapeutic target for the treatment of cancer.

Alternative-splicing defects in cancer: Splicing regulators and their downstream targets, guiding the way to novel cancer therapeutics

Defects in alternative splicing are frequently found in human tumors and result either from mutations in splicing-regulatory elements of specific cancer genes or from changes in the regulatory splicing machinery. RNA splicing regulators have emerged as a new class of oncoproteins and tumor suppressors, and contribute to disease progression by modulating RNA isoforms involved in the hallmark cancer pathways. Thus, dysregulation of alternative RNA splicing is fundamental to cancer and provides a potentially rich source of novel therapeutic targets. Here, we review the alterations in splicing regulatory factors detected in human tumors, as well as the resulting alternatively spliced isoforms that impact cancer hallmarks, and discuss how they contribute to disease pathogenesis. RNA splicing is a highly regulated process and, as such, the regulators are themselves tightly regulated. Differential transcriptional and posttranscriptional regulation of splicing factors modulates their levels and activities in tumor cells. Furthermore, the composition of the tumor microenvironment can also influence which isoforms are expressed in a given cell type and impact drug responses. Finally, we summarize current efforts in targeting alternative splicing, including global splicing inhibition using small molecules blocking the spliceosome or splicing-factor-modifying enzymes, as well as splice-switching RNA-based therapeutics to modulate cancer-specific splicing isoforms. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing.

Bivalent Chromatin Domains in Glioblastoma Reveal a Subtype-Specific Signature of Glioma Stem Cells

Glioblastoma multiforme (GBM) can be clustered by gene expression into four main subtypes associated with prognosis and survival, but enhancers and other gene-regulatory elements have not yet been identified in primary tumors. Here, we profiled six histone modifications and CTCF binding as well as gene expression in primary gliomas and identified chromatin states that define distinct regulatory elements across the tumor genome. Enhancers in mesenchymal and classical tumor subtypes drove gene expression associated with cell migration and invasion, whereas enhancers in proneural tumors controlled genes associated with a less aggressive phenotype in GBM. We identified bivalent domains marked by activating and repressive chromatin modifications. Interestingly, the gene interaction network from common (subtype-independent) bivalent domains was highly enriched for homeobox genes and transcription factors and dominated by SHH and Wnt signaling pathways. This subtype-independent signature of early neural development may be indicative of poised dedifferentiation capacity in glioblastoma and could provide potential targets for therapy.Significance: Enhancers and bivalent domains in glioblastoma are regulated in a subtype-specific manner that resembles gene regulation in glioma stem cells. Cancer Res; 78(10); 2463-74. ©2018 AACR.

Down-regulation of miR-30a-3p/5p promotes esophageal squamous cell carcinoma cell proliferation by activating the Wnt signaling pathway

AIM

To investigate the potential role of microRNA-30a (miR-30a) in esophageal squamous cell carcinoma (ESCC).

METHODS

Expression of miR-30a-3p/5p was analyzed using microarray data and fresh ESCC tissue samples. Both in vitro and in vivo assays were used to investigate the effects of miR-30a-3p/5p on ESCC cell proliferation. Furthermore, Kyoto Encyclopedia of Genes and Genomes analysis was performed to explore underlying mechanisms involved in ESCC, and then, assays were carried out to verify the potential molecular mechanism of miR-30a in ESCC.

RESULTS

Low expression of miR-30a-3p/5p was closely associated with advanced ESCC progression and poor prognosis of patients with ESCC. Knock-down of miR-30a-3p/5p promoted ESCC cell proliferation. Increased miR-30a-3p/5p expression inhibited the Wnt signaling pathway by targeting Wnt2 and Fzd2.

CONCLUSION

Down-regulation of miR-30a-3p/5p promotes ESCC cell proliferation by activating the Wnt signaling pathway through inhibition of Wnt2 and Fzd2.

Identification of the key miRNAs associated with survival time in stomach adenocarcinoma

Stomach adenocarcinoma (STAD) is one of the leading causes of cancer morbidity and mortality worldwide. The present study aimed to identify the microRNAs associated with STAD survival time. The clinical information and microarray miRNA and mRNA expression profiles of STAD patients were downloaded from The Cancer Genome Atlas. Differential expression (DE) analysis was performed to identify DEmiRNAs and DEmRNAs in STAD. The DEmiRNAs associated with the survival time of patients with STAD were identified through DE analysis, negative correlation pair analysis, miRNA target gene prediction, univariate Cox regression analysis and Kaplan-Meier analysis. The functions of the target genes of the DEmiRNAs were predicted with Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. A total of 355 DEmiRNAs and 1,722 DEmRNAs were identified between STAD and normal tissues. A total of 5 DEmiRNAs were identified to be associated with STAD survival, including 4 risk-associated DEmiRNAs (miR-30a, -143, -145 and -133b) and 1 protective DEmiRNA (miR-135b). The target DEmRNAs were significantly enriched for DNA metabolic process in the biological process GO category, and in KEGG cell cycle signaling pathways. Kaplan-Meier curves indicated that the overall survival time in the miR-30a, -143, -145 and -133b high expression groups was significantly shorter than that in the low expression groups, whereas the survival time was prolonged in the miR-135b high expression group compared with that in the low expression group. Therefore, miR-30a, -143, -145, -133b and -135b may be involved in the tumorigenesis and development of STAD, and may be potential biomarkers for its early diagnosis and prognosis.

[Yiqihuoxue prescription promotes nerve regeneration by miR-124-mediated regulation of Wnt signaling in rats]

OBJECTIVE

To investigate the effect of Yiqihuoxue prescription (NLXT) on nerve regeneration in MCAO-R rat models of qi deficiency and blood stasis syndrome and explore the underlying mechanisms.

METHODS

The rats were randomized into 4 groups, namely the control group, model group, NLXT group and TXL group. The rats in NLXT group and TXL group were treated with gavage of NLXT and TXL solutions, respectively. The NFDS, QDSS and BSSS of the rats were evaluated. The regional cerebral blood flow (rCBF) were dynamically monitored with laser Doppler scanning, and the volume of cerebral infarction was detected with TTC-dye; the expression levels of nestin and BrdU were assayed with immunohistochemistry and mmunofluorescent staining. The expressions of miRNA-124, Wnt3a, GSK3β and β-catenin in the rat brain tissue were detected with PCR or Western blotting.

RESULTS

NLXT and TXL both improved the neurological functions of the model rats, reduced NFDS, QDSS, and BSSS scores, decreased the volume of cerebral infarction, and promoted the recovery of the rCBF (P<0.01). Nestin and BrdU expression levels were significantly increased in the rat brain tissue in NLXT group and TXL group. NLXT significantly inhibited high expressions of miRNA-124 and Wnt3a in response to stress, and increased β-catenin expression level (P<0.01). NLXT and TXL produced no obvious effect on GSK3β expression in the model rats (P>0.05).

CONCLUSION

NLXT can activate Wnt signaling by affecting miRNA-124 expression to offer neuroprotection and promote nerve regeneration in rats with cerebral ischemia with qi deficiency and blood stasis syndrome.

Oncogenic Role of MicroRNA-30b-5p in Glioblastoma Through Targeting Proline-Rich Transmembrane Protein 2

MicroRNAs (miRs) have been found to play promoting or suppressive roles in different human cancers. However, the exact regulatory mechanism of miR-30b in glioblastoma remains unknown. Here we have shown that the expression of miR-30b is significantly increased in glioblastoma tissues and cell lines. Moreover, a high expression of miR-30b is significantly associated with a shorter survival time for glioblastoma patients. Knockdown of miR-30b caused a significant reduction in the proliferation, migration, and invasion of U87 and A172 cells. Proline-rich transmembrane protein 2 (PRRT2) was further identified as a novel target gene of miR-30b, and its protein expression is negatively regulated by miR-30b in U87 and A172 cells. Furthermore, PRRT2 is significantly downregulated in glioblastoma tissues and cell lines, and we found an inverse correlation between miR-30b and PRRT2 expression in glioblastoma tissues. In addition, inhibition of PRRT2 reversed the suppressive effect of miR-30b downregulation on the malignant phenotypes of U87 and A172 cells. Accordingly, we demonstrated that miR-30b promotes glioblastoma cell proliferation, migration, and invasion via targeting PRRT2. Therefore, miR-30b may be used as a promising therapeutic target for glioblastoma.

The role of miR-130a in cancer

MicroRNAs (miRs) are short and highly conserved non-coding RNAs molecules consisting of 18-25 nucleotides that regulate gene expression at post-transcriptional level by direct binding to complementary binding sites within the 3'untranslated region (3'UTR) of target mRNAs. New evidences have demonstrated that miRNAs play an important role in diverse physiological processes, including regulating cell growth, apoptosis, metastasis, drug resistance, and invasion. In chromosomes 11 and 22 of the miR-130 family, paralogous miRNA sequences, miR-130a and miR-130b are situated, respectively. MiR-130a has participated in different pathogenesis, including hepatocellular carcinoma, cervical cancer, ovarian cancer, glioblastoma, prostate carcinoma, leukemia, etc. Most important of all, more and more evidences indicate that miR-130a is associated with drug resistance and acts as an intermediate in PI3 K/Akt/PTEN/mTOR, Wnt/β-catenin and NF-kB/PTEN drug resistance signaling pathways. Drug resistance has emerged as a major obstacle to successful treatment of cancer nowadays and in this review, we will reveal the function of miR-130a in cancer, especially in drug resistance. Therefore, it will provide a new therapeutic target for the treatment of cancer, especially in chemotherapy.

Down-regulation of MicroRNA-133 predicts poor overall survival and regulates the growth and invasive abilities in glioma

miRNAs were reported as oncogene or tumour suppressors in various cancers and played important roles in tumour development and progression. Dysregulated miR-133 has been reported in several cancers, however, the expression and biological function of miR-133 in glioma remained unclear. In this study, we found that miR-133 expression level was significantly decreased in glioma tissues and cell lines by RT-qPCR. Then miR-133 mimics were used to evaluate the effects of miR-133 on cell proliferation and invasion in vitro. We found that overexpressed miR-133 could significantly suppress cell growth, and invasion in U87 cells. Additionally, we found that forkhead box C1 (FOXC1) was overexpressed in glioma tissue and it was directly regulated by miR-133. Overall, this study is the first proof to demonstrate that miR-133 function as tumour suppressor in glioma and inhibit cell proliferation and invasioned by directly targeting FOXC1, implying miR-133 as a potential therapeutic target for glioma.

Exosomal microRNA miR-1246 induces cell motility and invasion through the regulation of DENND2D in oral squamous cell carcinoma

Metastasis is associated with poor prognosis in cancers. Exosomes, which are packed with RNA and proteins and are released in all biological fluids, are emerging as an important mediator of intercellular communication. However, the function of exosomes remains poorly understood in cancer metastasis. Here, we demonstrate that exosomes isolated by size-exclusion chromatography from a highly metastatic human oral cancer cell line, HOC313-LM, induced cell growth through the activation of ERK and AKT as well as promoted cell motility of the poorly metastatic cancer cell line HOC313-P. MicroRNA (miRNA) array analysis identified two oncogenic miRNAs, miR-342–3p and miR-1246, that were highly expressed in exosomes. These miRNAs were transferred to poorly metastatic cells by exosomes, which resulted in increased cell motility and invasive ability. Moreover, miR-1246 increased cell motility by directly targeting DENN/MADD Domain Containing 2D (DENND2D). Taken together, our findings support the metastatic role of exosomes and exosomal miRNAs, which highlights their potential for applications in miRNA-based therapeutics.

How Wnt Signaling Builds the Brain: Bridging Development and Disease

Wnt/β-catenin signaling plays a crucial role throughout all stages of brain development and remains important in the adult brain. Accordingly, many neurological disorders have been linked to Wnt signaling. Defects in Wnt signaling during neural development can give rise to birth defects or lead to neurological dysfunction later in life. Developmental signaling events can also be hijacked in the adult and result in disease. Moreover, knowledge about the physiological role of Wnt signaling in the brain might lead to new therapeutic strategies for neurological diseases. Especially, the important role for Wnt signaling in neural differentiation of pluripotent stem cells has received much attention as this might provide a cure for neurodegenerative disorders. In this review, we summarize the versatile role of Wnt/β-catenin signaling during neural development and discuss some recent studies linking Wnt signaling to neurological disorders.

MiR-301a is activated by the Wnt/β-catenin pathway and promotes glioma cell invasion by suppressing SEPT7

BACKGROUND

miR-301a is frequently dysregulated and specific to human tumors, playing a critical role in tumorigenesis; however, the exact functions and regulatory mechanisms of miR-301a in glioma cells remain largely unknown. Herein, we show that miR-301a activated by the Wnt/β-catenin pathway promoted the invasion of glioma cells by directly targeting SEPT7.

METHODS

Biochemical, luciferase reporter, and hromatin immunoprecipitation PCR assays characterized the function and regulatory mechanisms of miR-301a in glioma invasion.

RESULTS

Initially, we detected the expression of miR-301a in glioma tissues and identified that miR-301a had increased, with ascending grades of the tumor. Furthermore, high levels of miR-301a were associated with a poorer prognosis in glioma patients. It is important to note that the Wnt/β-catenin/TCF4 pathway enhanced miR-301a expression by binding to the promoter region. To determine the oncogenic functions of miR-301a in glioma, SEPT7 was supported as the direct target gene. In addition, the Wnt/β-catenin pathway repressed SEPT7 expression, which was dependent on miR-301a in glioma cells. Finally, miR-301a was activated by Wnt/β-catenin and then promoted invasion of glioma cells by inhibiting the expression of SEPT7 in vitro and in vivo.

CONCLUSIONS

Our findings revealed the mechanism of action for miR-301a in tumor cell invasion. Moreover, the Wnt/miR-301a/SEPT7 signaling axis might be a novel target in treating glioma.