Circulating miR-182 is a biomarker of colorectal adenocarcinoma progression. Oncotarget. 2014;5:6611-6619. [PMID: 25115394 PMCID: PMC4196150 DOI: 10.18632/oncotarget.2245]

IDH1 mutation produces R-2-hydroxyglutarate (R-2HG) and induces mir-182-5p expression to regulate cell cycle and tumor formation in glioma

BACKGROUND

Mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2), are present in most gliomas. IDH1 mutation is an important prognostic marker in glioma. However, its regulatory mechanism in glioma remains incompletely understood.

RESULTS

miR-182-5p expression was increased within IDH1-mutant glioma specimens according to TCGA, CGGA, and online dataset GSE119740, as well as collected clinical samples. (R)-2-hydroxyglutarate ((R)-2HG) treatment up-regulated the expression of miR-182-5p, enhanced glioma cell proliferation, and suppressed apoptosis; miR-182-5p inhibition partially eliminated the oncogenic effects of R-2HG upon glioma cells. By direct binding to Cyclin Dependent Kinase Inhibitor 2 C (CDKN2C) 3'UTR, miR-182-5p inhibited CDKN2C expression. Regarding cellular functions, CDKN2C knockdown promoted R-2HG-treated glioma cell viability, suppressed apoptosis, and relieved cell cycle arrest. Furthermore, CDKN2C knockdown partially attenuated the effects of miR-182-5p inhibition on cell phenotypes. Moreover, CDKN2C knockdown exerted opposite effects on cell cycle check point and apoptosis markers to those of miR-182-5p inhibition; also, CDKN2C knockdown partially attenuated the functions of miR-182-5p inhibition in cell cycle check point and apoptosis markers. The engineered CS-NPs (antagomir-182-5p) effectively encapsulated and delivered antagomir-182-5p, enhancing anti-tumor efficacy in vivo, indicating the therapeutic potential of CS-NPs(antagomir-182-5p) in targeting the miR-182-5p/CDKN2C axis against R-2HG-driven oncogenesis in mice models.

CONCLUSIONS

These insights highlight the potential of CS-NPs(antagomir-182-5p) to target the miR-182-5p/CDKN2C axis, offering a promising therapeutic avenue against R-2HG's oncogenic influence to glioma.

Cross-Kingdom Interaction of miRNAs and Gut Microbiota with Non-Invasive Diagnostic and Therapeutic Implications in Colorectal Cancer

Colorectal cancer (CRC) has one of the highest incidences among all types of malignant diseases, affecting millions of people worldwide. It shows slow progression, making it preventable. However, this is not the case due to shortcomings in its diagnostic and management procedure and a lack of effective non-invasive biomarkers for screening. Here, we discuss CRC-associated microRNAs (miRNAs) and gut microbial species with potential as CRC diagnostic and therapy biomarkers. We provide rich evidence of cross-kingdom miRNA-mediated interactions between the host and gut microbiome. miRNAs have emerged with the ability to shape the composition and dynamics of gut microbiota. Intestinal microbes can uptake miRNAs, which in turn influence microbial growth and provide the ability to regulate the abundance of various microbial species. In the context of CRC, targeting miRNAs could aid in manipulating the balance of the microbiota. Our findings suggest the need for correlation analysis between the composition of the gut microbiome and the miRNA expression profile.

Role of MicroRNA-223 and MicroRNA-182 as Novel Biomarkers in Early Detection of Colorectal Cancer

Background

Colorectal cancer is a common and lethal disease. It is estimated that approximately 145,600 new cases of large bowel cancer are diagnosed annually in the USA. MiRNA-223 and miRNA-182 have been reported in various cancers, such as lung, gastric, breast and colorectal cancer and proposed to be valid and reliable for diagnosis as well as prognosis.

Aim

This study aimed to determine the role of miR-223 and miR-182 as novel biomarkers for early detection and prognosis of CRC.

Patient and Methods

This case–control study was conducted at the department of Internal Medicine, Aswan University Hospital, in the period from the 1st of February 2020 to the 20th of April 2021. Thirty-five cases and thirty age- and sex-matched controls were included in the study. All patients were subject to complete clinical evaluation, routine investigations, occult blood in stool, serum levels of CEA and CA 19–9, serum levels of miR-223 and miR-182 by quantitative PCR.

Results

Significant difference between the two studied groups regarding biomarker changes was found. ROC curve analysis showed that the new markers had excellent diagnostic as well as prognostic criteria. Micro-RNA-223 diagnostic accuracy, sensitivity, specificity, PPV, NPV, FDR and FOR were 97%, 97.1%, 96.7%, 97%, 97%, 3.3% and 2.9%, respectively. Also, micro-RNA-182 diagnostic accuracy, sensitivity, specificity, PPV, NPV, FDR and FOR were 97%, 98%, 96%, 96%, 98%, 3.9% and 2%, respectively.

Conclusion

MiR-223 and miR-182 have been discovered to be relevant and reliable biomarkers for the early identification and prognosis of CRC. Increased levels of miR-223 and miR-182 were associated with increased risk of disease progression, and the more accurate the value of miR-223 and miR-182, the earlier the diagnosis of colorectal cancer.

miR-182 targeting reprograms tumor-associated macrophages and limits breast cancer progression

Breast cancer is a major threat of women’s health worldwide. Nontumor cell components play crucial roles in cancer. Macrophages, the cells of the innate immune system that normally exert antitumor activities, can be educated by tumors to an alternatively activated phenotype that is known to promote tumor progression. Understanding the mechanism of macrophage education by tumor cells will help the design of new therapeutic approaches. We find that breast tumor cells induce the expression of a microRNA, miR-182, in macrophages, and miR-182 promotes macrophage alternative activation to drive tumor development. Importantly, using cationized mannan-modified extracellular vesicles to load miR-182 inhibitors and deliver the inhibitors specifically into macrophages can effectively inhibit alternative activation of macrophages and suppress breast tumor development.

The protumor roles of alternatively activated (M2) tumor-associated macrophages (TAMs) have been well established, and macrophage reprogramming is an important therapeutic goal. However, the mechanisms of TAM polarization remain incompletely understood, and effective strategies for macrophage targeting are lacking. Here, we show that miR-182 in macrophages mediates tumor-induced M2 polarization and can be targeted for therapeutic macrophage reprogramming. Constitutive miR-182 knockout in host mice and conditional knockout in macrophages impair M2-like TAMs and breast tumor development. Targeted depletion of macrophages in mice blocks the effect of miR-182 deficiency in tumor progression while reconstitution of miR-182-expressing macrophages promotes tumor growth. Mechanistically, cancer cells induce miR-182 expression in macrophages by TGFβ signaling, and miR-182 directly suppresses TLR4, leading to NFκb inactivation and M2 polarization of TAMs. Importantly, therapeutic delivery of antagomiR-182 with cationized mannan-modified extracellular vesicles effectively targets macrophages, leading to miR-182 inhibition, macrophage reprogramming, and tumor suppression in multiple breast cancer models of mice. Overall, our findings reveal a crucial TGFβ/miR-182/TLR4 axis for TAM polarization and provide rationale for RNA-based therapeutics of TAM targeting in cancer.

Circulating Exosomal microRNAs as Predictive Biomarkers of Neoadjuvant Chemotherapy Response in Breast Cancer

Background: Neoadjuvant chemotherapy (NACT) is an increasingly used approach for treatment of breast cancer. The pathological complete response (pCR) is considered a good predictor of disease-specific survival. This study investigated whether circulating exosomal microRNAs could predict pCR in breast cancer patients treated with NACT. Method: Plasma samples of 20 breast cancer patients treated with NACT were collected prior to and after the first cycle. RNA sequencing was used to determine microRNA profiling. The Cancer Genome Atlas (TCGA) was used to explore the expression patterns and survivability of the candidate miRNAs, and their potential targets based on the expression levels and copy number variation (CNV) data. Results: Three miRNAs before that NACT (miR-30b, miR-328 and miR-423) predicted pCR in all of the analyzed samples. Upregulation of miR-127 correlated with pCR in triple-negative breast cancer (TNBC). After the first NACT dose, pCR was predicted by exo-miR-141, while miR-34a, exo-miR182, and exo-miR-183 predicted non-pCR. A significant correlation between the candidate miRNAs and the overall survival, subtype, and metastasis in breast cancer, suggesting their potential role as predictive biomarkers of pCR. Conclusions: If the miRNAs identified in this study are validated in a large cohort of patients, they might serve as predictive non-invasive liquid biopsy biomarkers for monitoring pCR to NACT in breast cancer.

The oncogenic role of HIF-1α/miR-182-5p/ZFP36L1 signaling pathway in nasopharyngeal carcinoma

Background

Accumulating evidence indicates that dysregulation of miR-182-5p can serve as diagnostic and prognostic biomarkers for some cancers, whereas the role of miR-182-5p has not been explored in nasopharyngeal carcinoma (NPC). Our study aims to elucidate the biological function of miR-182-5p in NPC and the potential molecular mechanism involved.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to determine miR-182-5p expression in NPC primary tissues and cell lines. Immunohistochemistry (IHC) for ZFP36L1 was conducted in NPC samples. Western blot was used to evaluate protein expression in cell lines. A series of functional assays were carried out to evaluate the roles of miR-182-5p and ZFP36L1 in tumor development and progression of NPC. Bioinformatics tools and luciferase reporter assays were utilized to identify the potential mechanisms of action. Moreover, rescue experiments were applied to explore whether ZFP36L1 mediated the effects of miR-182-5p in NPC.

Results

Up-regulation of miR-182-5p was significantly associated with tumor development and poor prognosis in patients with NPC. Functional study demonstrated that miR-182-5p overexpression enhanced, whereas suppression of miR-182-5p impeded NPC cell proliferation, migration, tumorigenesis and metastasis. Mechanistically, miR-182-5p interacted with ZFP36L1 at two sites in its 3′ un-translated region (UTR) and repressed ZFP36L1 expression in NPC. Consistently, an inverse correlation was observed between the expression levels of miR-182-5p and ZFP36L1 using clinical NPC tissues, and down-regulation of ZFP36L1 in NPC predicts poor survival. Furthermore, overexpression of miR-182-5p in NPC was partly attributable to the transcriptional activation effect induced by hypoxia-inducible factor 1α (HIF-1α).

Conclusions

Our data suggests that miR-182-5p facilitates cell proliferation and migration in NPC through its ability to down-regulate ZFP36L1 expression, and that the HIF-1α/miR-182-5p/ZFP36L1 axis may serve as a novel therapeutic target in the management of NPC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02177-3.

miRNA Clusters with Up-Regulated Expression in Colorectal Cancer

Simple Summary

As miRNAs show the capacity to be used as CRC biomarkers, we analysed experimentally validated data about frequently up-regulated miRNA clusters in CRC tissue. We identified 15 clusters that showed increased expression in CRC: miR-106a/363, miR-106b/93/25, miR-17/92a-1, miR-181a-1/181b-1, miR-181a-2/181b-2, miR-181c/181d, miR-183/96/182, miR-191/425, miR-200c/141, miR-203a/203b, miR-222/221, mir-23a/27a/24-2, mir-29b-1/29a, mir-301b/130b and mir-452/224. Cluster positions in the genome are intronic or intergenic. Most clusters are regulated by several transcription factors, and by long non-coding RNAs. In some cases, co-expression of miRNA with other cluster members or host gene has been proven. miRNA expression patterns in cancer tissue, blood and faeces were compared. The members of the selected clusters target 181 genes. Their functions and corresponding pathways were revealed with the use of Panther analysis. Clusters miR-17/92a-1, miR-106a/363, miR-106b/93/25 and miR-183/96/182 showed the strongest association with metastasis occurrence and poor patient survival, implicating them as the most promising targets of translational research.

Abstract

Colorectal cancer (CRC) is one of the most common malignancies in Europe and North America. Early diagnosis is a key feature of efficient CRC treatment. As miRNAs can be used as CRC biomarkers, the aim of the present study was to analyse experimentally validated data on frequently up-regulated miRNA clusters in CRC tissue and investigate their members with respect to clinicopathological characteristics of patients. Based on available data, 15 up-regulated clusters, miR-106a/363, miR-106b/93/25, miR-17/92a-1, miR-181a-1/181b-1, miR-181a-2/181b-2, miR-181c/181d, miR-183/96/182, miR-191/425, miR-200c/141, miR-203a/203b, miR-222/221, mir-23a/27a/24-2, mir-29b-1/29a, mir-301b/130b and mir-452/224, were selected. The positions of such clusters in the genome can be intronic or intergenic. Most clusters are regulated by several transcription factors, and miRNAs are also sponged by specific long non-coding RNAs. In some cases, co-expression of miRNA with other cluster members or host gene has been proven. miRNA expression patterns in cancer tissue, blood and faeces were compared. Based on experimental evidence, 181 target genes of selected clusters were identified. Panther analysis was used to reveal the functions of the target genes and their corresponding pathways. Clusters miR-17/92a-1, miR-106a/363, miR-106b/93/25 and miR-183/96/182 showed the strongest association with metastasis occurrence and poor patient survival, implicating them as the most promising targets of translational research.

MicroRNAs in Medullary Thyroid Carcinoma: A State of the Art Review of the Regulatory Mechanisms and Future Perspectives

Medullary thyroid carcinoma (MTC) is a rare malignant neoplasia with a variable clinical course, with complete remission often difficult to achieve. Genetic alterations lead to fundamental changes not only in hereditary MTC but also in the sporadic form, with close correlations between mutational status and prognosis. In recent years, microRNAs (miRNAs) have become highly relevant as crucial players in MTC etiology. Current research has focused on their roles in disease carcinogenesis and development, but recent studies have expounded their potential as biomarkers and response predictors to novel biological drugs for advanced MTC. One such element which requires greater investigation is their mechanism of action and the molecular pathways involved in the regulation of gene expression. A more thorough understanding of these mechanisms will help realize the promising potential of miRNAs for MTC therapy and management.

Circulating microRNA Expression in Cushing's Syndrome

Context

Cushing's syndrome (CS) is a rare disease of endogenous hypercortisolism associated with high morbidity and mortality. Diagnosis and classification of CS is still challenging.

Objective

Circulating microRNAs (miRNAs) are minimally invasive diagnostic markers. Our aim was to characterize the circulating miRNA profiles of CS patients and to identify distinct profiles between the two major CS subtypes.

Methods

We included three groups of patients from the German Cushing's registry: ACTH-independent CS (Cortisol-Producing-Adenoma; CPA), ACTH-dependent pituitary CS (Cushing's Disease; CD), and patients in whom CS had been ruled out (controls). Profiling of miRNAs was performed by next-generation-sequencing (NGS) in serum samples of 15 CS patients (each before and after curative surgery) and 10 controls. Significant miRNAs were first validated by qPCR in the discovery cohort and then in an independent validation cohort of 20 CS patients and 11 controls.

Results

NGS identified 411 circulating miRNAs. Differential expression of 14 miRNAs were found in the pre- and postoperative groups. qPCR in the discovery cohort validated 5 of the significant miRNAs from the preoperative group analyses. Only, miR-182-5p was found to be significantly upregulated in the CD group of the validation cohort. Comparing all CS samples as a group with the controls did not reveal any significant differences in expression.

Outcome

In conclusion, our study identified miR-182-5p as a possible biomarker for CD, which has to be validated in a prospective cohort. Furthermore, our results suggest that presence or absence of ACTH might be at least as relevant for miRNA expression as hypercortisolism itself.

miR-182-3p/Myadm contribute to pulmonary artery hypertension vascular remodeling via a KLF4/p21-dependent mechanism

Rationale: There is a continued need for investigating the roles of microRNAs and their targets on the pathogenesis of pulmonary arterial hypertension (PAH) vascular remodeling. We recently identified the association of myeloid miR-182-3p and its new target, Myeloid-Associated Differentiation Marker (Myadm), with vascular remodeling. Here, we aimed to determine the role of miR-182-3p/Myadm on PAH vascular remodeling and the underlying molecular mechanism. Methods: The miR-182-3p/Myadm expression profiles were detected in PAH patients and experimental rodent models. Loss-of-function and gain-of-function studies using gene knock-in or gene knock-out and the combinations of the proteomic technology and genome-wide ChIP-Seq were employed to determine the downstream targets of miR-182-3p/Myadm in response to monocrotaline (MCT)-induced PAH. Results: The miR-182-3p/Myadm expression was altered in PAH patients and experimental rodent models. Both miR-182-3p inhibitor and overexpression of Myadm augmented the pathological progression in rats in response to MCT-induced PAH. In contrast, miR-182-3p mimic and Myadm gene knockout attenuated the changes in the hemodynamics and structure of the cardio-pulmonary system in MCT-induced PAH in rats. Myadm mediated the proliferation of pulmonary artery smooth muscle cells (PASMCs) by altering the cell cycle kinase inhibitor (p21/Cip1) expression through the transcription factor Krüppel-like factor 4 (KLF4) translocation into the cytoplasm. Conclusion: Our findings indicate the prognostic and therapeutic significance of miR-182-3p in PAH and provide a new regulatory model of the myeloid-derived miR-182-3p/Myadm/KLF4/p21 axis in PAH vascular remodeling.

Prognostic values and prospective pathway signaling of MicroRNA-182 in ovarian cancer: a study based on gene expression omnibus (GEO) and bioinformatics analysis

BACKGROUND

Ovarian carcinoma (OC) is a common cause of death among women with gynecological cancer. MicroRNAs (miRNAs) are believed to have vital roles in tumorigenesis of OC. Although miRNAs are broadly recognized in OC, the role of has-miR-182-5p (miR-182) in OC is still not fully elucidated.

METHODS

We evaluated the significance of miR-182 expression in OC by using analysis of a public dataset from the Gene Expression Omnibus (GEO) database and a literature review. Furthermore, we downloaded three mRNA datasets of OC and normal ovarian tissues (NOTs), GSE14407, GSE18520 and GSE36668, from GEO to identify differentially expressed genes (DEGs). Then the targeted genes of hsa-miR-182-5p (TG_miRNA-182-5p) were predicted using miRWALK3.0. Subsequently, we analyzed the gene overlaps integrated between DEGs in OC and predicted target genes of miR-182 by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. STRING and Cytoscape were used to construct a protein-protein interaction (PPI) network and the prognostic effects of the hub genes were analyzed.

RESULTS

A common pattern of up-regulation for miR-182 in OC was found in our review of the literature. A total of 268 DEGs, both OC-related and miR-182-related, were identified, of which 133 genes were discovered from the PPI network. A number of DEGs were enriched in extracellular matrix organization, pathways in cancer, focal adhesion, and ECM-receptor interaction. Two hub genes, MCM3 and GINS2, were significantly associated with worse overall survival of patients with OC. Furthermore, we identified covert miR-182-related genes that might participate in OC by network analysis, such as DCN, AKT3, and TIMP2. The expressions of these genes were all down-regulated and negatively correlated with miR-182 in OC.

CONCLUSIONS

Our study suggests that miR-182 is essential for the biological progression of OC.

MiRNAs roles in the diagnosis, prognosis and treatment of colorectal cancer

Introduction: The liver is the main location for metastasization in stage IV colorectal cancers. Areas covered: This review intends to comprehensively present the most important studies conducted in the past few years concerning the role of miRNAs in colorectal cancer liver metastases, trying to clarify some aspects regarding tumor biology and favorite liver metastasization site. Expert commentary: Recent advances in tissue and serum RNA extraction has considerably improved the field of microRNAs studies. These molecules known to play a crucial role in the metastatic stage indicate a starting point in the development of clinical biomarkers with a possible role in the stratification of high-risk patients for adequate treatment.

Silencing of miR-182 is associated with modulation of tumorigenesis through apoptosis induction in an experimental model of colorectal cancer

BACKGROUND

miR-182-5p (miR-182) is an oncogenic microRNA (miRNA) found in different tumor types and one of the most up-regulated miRNA in colorectal cancer (CRC). Although this microRNA is expressed in the early steps of tumor development, its role in driving tumorigenesis is unclear.

METHODS

The effects of miR-182 silencing on transcriptomic profile were investigated using two CRC cell lines characterized by different in vivo biological behavior, the MICOL-14^h-tert cell line (dormant upon transfer into immunodeficient hosts) and its tumorigenic variant, MICOL-14^tum. Apoptosis was studied by annexin/PI staining and cleaved Caspase-3/PARP analysis. The effect of miR-182 silencing on the tumorigenic potential was addressed in a xenogeneic model of MICOL-14^tum transplant.

RESULTS

Endogenous miR-182 expression was higher in MICOL-14^tum than in MICOL-14^h-tert cells. Interestingly, miR-182 silencing had a strong impact on gene expression profile, and the positive regulation of apoptotic process was one of the most affected pathways. Accordingly, annexin/PI staining and caspase-3/PARP activation demonstrated that miR-182 treatment significantly increased apoptosis, with a prominent effect in MICOL-14^tum cells. Moreover, a significant modulation of the cell cycle profile was exerted by anti-miR-182 treatment only in MICOL-14^tum cells, where a significant increase in the fraction of cells in G0/G1 phases was observed. Accordingly, a significant growth reduction and a less aggressive histological aspect were observed in tumor masses generated by in vivo transfer of anti-miR-182-treated MICOL-14^tum cells into immunodeficient hosts.

CONCLUSIONS

Altogether, these data indicate that increased miR-182 expression may promote cell proliferation, suppress the apoptotic pathway and ultimately confer aggressive traits on CRC cells.

Protective potential of miR-146a-5p and its underlying molecular mechanism in diverse cancers: a comprehensive meta-analysis and bioinformatics analysis

Background/aims

Studies have shown that miR-146a-5p was differentially expressed in diverse cancers, but the associations between miR-146a-5p expression and prognosis across multiple types of cancer as well its potential targets and downstream pathways have not been comprehensively analyzed. In this study, we performed the first meta-analysis of the prognostic value of miR-146a-5p expression in diverse malignancies and explored prospective targets of miR-146a-5p and related signaling pathways.

Methods

A thorough search for articles related to miR-146a-5p was performed, and RNA-seq data from The Cancer Genome Atlas (TCGA) and microarray data from gene expression omnibus profiles were used to collect information about the prognostic value of miR-146a-5p. A comprehensive meta-analysis was conducted. Twelve platforms in miRWalk 2.0 were applied to predict targets of miR-146a-5p. TCGA RNA-seq data were used to validate the inverse relationships between miR-146a-5p and its likely targets. Subsequently, gene ontology and pathway analyses were conducted using Funrich version 3.1.3. Potential protein–protein interaction (PPI) networks were constructed. Potential target genes of miR-146a-5p in lung cancer were validated by RT-qPCR.

Results

We included 10 articles in the meta-analysis. In a pooled analysis, the high miR-146a-5p expression group showed a better overall survival in solid cancers, particularly in reproductive system cancers and digestive system cancers. A total of 120 predicted target genes were included in a bioinformatics analysis. Five pathways involving phospholipase C (PLC) and aquaporins (AQPs) were the most significantly enriched Kyoto Encyclopedia of Genes and Genomes pathways. Moreover, the PPI network displayed the related signaling pathways and interactions among proteins. AQP1 and FYN were validated by RT-qPCR to be potential targets of miR-146a-5p in lung cancer.

Conclusion

There is a close link between high miR-146a-5p expression and better overall survival in 21 types of solid cancer, especially in reproductive system and digestive system cancers. Furthermore, miR-146a-5p could inhibit diverse malignancies by modulating pathways linked to PLC or AQPs. In summary, miR-146a-5p is a potential prognostic biomarker and therapeutic target for various cancers.

Role of kinesin superfamily in gastrointestinal cancer

Kinesins constitute a protein superfamily that belongs to motor proteins. Kinesins move along microtubules to exert their functions. They play a crucial role in intracellular transportation, mitosis, cell formation, and cell function. Kinesin are not only responsible for the transport of various membrane organelles, protein complexes, mRNA and so on to ensure the basic activity of cells, but also can regulate intracellular molecular signal pathways. Numerous studies have shown that kinesins are closely associated with the development of a variety of human diseases, especially the formation and development of gastrointestinal tumors. This article reviews the role of kinesins in gastrointestinal cancer.

MicroRNA-182 inhibits HCMV replication through activation of type I IFN response by targeting FOXO3 in neural cells

Human cytomegalovirus (HCMV) has led to kinds of clinical disorders and great morbidity worldwide, such as sensorineural hearing loss (SNHL), mental retardation, and developmental delays in immunocompromised individuals. Congenital HCMV infection is a leading cause of birth defects, primarily manifesting as neurological disorders. Previous studies reported that HCMV has evolved a variety of mechanisms to evade the immune system, such as dysregulation of miRNAs. However, reports concerning the role of miRNA in HCMV infection in neural cells are limited. Here, we reported that a host microRNA, miR-182, was significantly up-regulated by HCMV infection in U-251MG and NPCs cells. Subsequently, our results of in vitro and in vivo experiments demonstrated that miR-182 was a positive regulator of interferon regulatory factor 7 (IRF7) by directly targeting FOXO3, resulting in the induction of IFN-I response and suppression of HCMV replication in neural cells. Taken together, our findings provide detailed molecular mechanisms of the antiviral function of miR-182 against HCMV infection in neural cells, and suggest an intrinsic anti-HCMV therapeutic target.

Elevated circulating miR-182 acts as a diagnostic biomarker for early colorectal cancer

Purpose

Globally, colorectal cancer (CRC) is one of the most common cancers with high mortality. Although CRC patients in stages I–II are curable after surgical resection, due to the lack of sensitive and specific biomarkers, many patients are in the advanced stages when diagnosed. This study aimed to investigate whether circulating miRNAs in plasma could act as biomarkers for early CRC diagnosis.

Patients and methods

All healthy subjects and patients were from Nanjing First Hospital. We first selected 2 differential miRNAs by integrated analysis of 4 Gene Expression Omnibus (GEO) data sets and The Cancer Genome Atlas (TCGA) database. Next, the expression of these 2 miRNAs in tissue and plasma samples were examined through quantitative real-time polymerase chain reaction. Training phase and validation phase were designed to investigate the diagnostic utility of these differential miRNAs using receiver operating characteristic (ROC) curve analysis.

Results

After integrated analysis of 4 GEO and TCGA databases, upregulated miR-182 and miR-20a were selected to further investigate their diagnostic potential for CRC. We discovered that miR-182 and miR-20a were upregulated in CRC tissue and plasma and that circulating miR-182 and miR-20a in the plasma of CRC patients were tumor derived. The area under the ROC curve (AUC) of circulating miR-182 was 0.929 (95% CI 0.875–0.983) in the training phase and 0.891 (95% CI 0.821–0.961) in the validation phase. The AUC of circulating miR-20a expression was 0.801 (95% CI 0.695–0.906) in the training phase and 0.736 (95% CI 0.631–0.842) in the validation phase.

Conclusion

Circulating miR-182 is a novel potential biomarker for early CRC diagnosis.

MicroRNA-564 is downregulated in glioblastoma and inhibited proliferation and invasion of glioblastoma cells by targeting TGF-β1

Increasing evidence has indicated that aberrant expression of miRNAs has been shown to be strongly implicated in the initiation and progression of glioblastoma. Here, we identified a novel tumor suppressive miRNA, miR-564, and investigated its role and therapeutic effect for glioblastoma. We showed that miR-564 was down-regulated in human glioblastoma tissues and cell lines. Introduction of miR-564 dramatically inhibited cell growth and invasion in glioblastoma cells. Subsequent experiments revealed that Transforming growth factor-β1 (TGF-β1) was a direct and functional target of miR-564 in glioblastoma cells. Furthermore, overexpression of miR-564 decreased p-SMAD and SMAD4 expression, which are the downstream signaling molecules of TGF-β. Meanwhile, ectopic of miR-564 reduced the messenger RNA (mRNA) and protein expression of epidermal growth factor receptor (EGFR) and MMP9. Furthermore, the upregulation of miR-564 suppressed TGF-β-mediated U87 proliferation and migration. The expression of EGFR and MMP9 was upregulated in glioblastoma tissues compared to their normal tissues. The EGFR and MMP9 expression levels were inverse correlated with the expression of miR-564. miR-564 suppressed the growth of U87-engrafted tumors. These findings reveal that miR-564/TGF-β1 signaling that may be required for glioblastoma development and may consequently serve as a new therapeutic target for the treatment of glioblastoma.

Dysregulation and functional roles of miR-183-96-182 cluster in cancer cell proliferation, invasion and metastasis

Previous studies have reported aberrant expression of the miR-183-96-182 cluster in a variety of tumors, which indicates its' diagnostic or prognostic value. However, a key characteristic of the miR-183-96-182 cluster is its varied expression levels, and pleomorphic functional roles in different tumors or under different conditions. In most tumor types, the cluster is highly expressed and promotes tumorigenesis, cancer progression and metastasis; yet tumor suppressive effects have also been reported in some tumors. In the present study, we discuss the upstream regulators and the downstream target genes of miR-183-96-182 cluster, and highlight the dysregulation and functional roles of this cluster in various tumor cells. Newer insights summarized in this review will help readers understand the different facets of the miR-183-96-182 cluster in cancer development and progression.

Secretory microRNAs as biomarkers of cancer

MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression predominantly by inhibiting transcription and/or promoting degradation of target mRNAs also in addition to being involved in non-canonical mechanisms regulating transcription, translation and cell signaling processes. Extracellular secretory miRNAs, either in complex with specific proteins or encapsulated in microvesicles called exosomes, are transported between cells as means of intercellular communication. Secretory miRNAs in circulation remain functional after delivery to recipient cells, regulating target genes and their corresponding signaling pathways. Cancer cell secreted miRNA-mediated intercellular communication affects physiological processes associated with the disease, such as, angiogenesis, metabolic reprogramming, immune modulation, metastasis, and chemo-resistance. Given the stability of miRNAs in body fluids and their well-documented roles in deregulating cancer-relevant genetic pathways, there is considerable interest in developing secretory miRNAs as liquid biopsy biomarkers for detection, diagnosis and prognostication of cancer. In this review, we discuss salient features of miRNA biogenesis, secretion and function in cancer as well as the current state of secretory miRNA isolation and profiling methods. Furthermore, we discuss the challenges and opportunities of secretory miRNA biomarker assay development, which need to be addressed for clinical applications.

Serum miR-125b is a non-invasive predictive biomarker of the pre-operative chemoradiotherapy responsiveness in patients with rectal adenocarcinoma

Background

Therapeutic management of Locally Advanced Rectal Cancer (LARC) involves pre-operative chemoradiotherapy (pCRT) followed by surgery. However, after pCRT the complete pathological response is approximately 20%, whereas in 20 to 40% of patients the response is poor or absent.

Methods

Cancer biopsy specimens (n= 38) and serum samples (n= 34) obtained before pCRT from 38 LARC patients were included in the study. Patients were classified in responders (R, tumor regression grade [TRG] 1-2; n= 16) and non-responders (NR, TRG 3-5; n= 22) according to the pathological response observed upon surgery. We performed miRNA microarrays analysis on biopsy specimens, and validated the selected candidates both by qRT-PCR (tissue and serum) and by in situ hybridization (tissue, miR-125b) analyses.

Results

Eleven miRNAs were significantly different between R and NR (miR-154, miR-409-3p, miR-127-3p, miR-214*, miR-299-5p and miR-125b overexpressed in NR; miR-33a, miR-30e, miR-338-3p, miR-200a and miR-378 decreased). In particular, miR-125b resulted to be the best candidate to discriminate the two groups (AUC of 0.9026; 95% CI, 0.7618-1.043). Additionally, miR-125b serum levels were significantly overexpressed in NR patients compared to R (p-value=0.0087), with an excellent discriminating power (AUC of 0.782; 95% CI, 0.6123-0.9518).

Conclusions

The obtained results further support the clinical impact of miRNA analysis. High miR-125b expression in tissue and serum were associated with a poor treatment response in LARC patients, therefore miR-125b could be considered as a possible novel non-invasive biomarker of response in LARC treatment.

Circulating miRNAs expression profiling in drug-resistant epilepsy: Up-regulation of miR-301a-3p in a case of sudden unexpected death

Sudden and unexpected death in epilepsy (SUDEP) represents one of the most challenging fields for clinical, forensic and preventative pathology. Several authors have emphasized the search of innovative biomarkers related to drug-resistance for an appropriate risk stratification in these patients. However, no reliable biomarker has been implemented into clinical practice, so far. Herein, we present a case of SUDEP due to drug-resistant mesial temporal lobe epilepsy (MTLE) in which we performed miRNA expression profiling (miR-301a-3p, miR-194-5p, miR-30b-5p, mIR-342-5p, and miR-4446-3p) from both the plasma and the temporal lobe in comparison to ten autopsies for traumatic or asphyxia deaths. A significant up-regulation of miR-301a-3p in both the plasma (2.3 increase vs. controls) and the hippocampus (3.2-fold increase vs. controls) was evidenced, whereas the other tested miRNAs showed no significant expression differences between case and controls. Even preliminary, our results support miRNAs as an innovative class of biomarkers compatible with an adequate analysis of biospecimens obtained from forensic autopsies.

Small RNAs in Circulating Exosomes of Cancer Patients: A Minireview

Extracellular vesicles (EVs) secreted from many cell types play important roles in intercellular communication, both as paracrine and endocrine factors, as they can circulate in biological fluids, including plasma. Amid EVs, exosomes are actively secreted vesicles that contain proteins, lipids, soluble factors, and nucleic acids, including microRNAs (miRNAs) and other classes of small RNAs (sRNA). miRNAs are prominent post-transcriptional regulators of gene expression and epigenetic silencers of transcription. We concisely review the roles of miRNAs in cell-fate determination and development and their regulatory activity on almost all the processes and pathways controlling tumor formation and progression. Next, we consider the evidence linking exosomes to tumor progression, particularly to the setting-up of permissive pre-metastatic niches. The study of exosomes in patients with different survival and therapy response can inform on the possible correlations between exosomal cargo and disease features. Moreover, the exploration of circulating exosomes as possible sources of non-invasive biomarkers could give new implements for anti-cancer therapy and metastasis prevention. Since the characterization of sRNAs in exosomes of cancer patients sparks opportunities to better understand their roles in cancer, we briefly present current experimental and computational protocols for sRNAs analysis in circulating exosomes by RNA-seq.

TUSC7 acts as a tumor suppressor in colorectal cancer

Increasing studies showed that long non-coding RNAs (lncRNAs) played important roles in the development and progression of tumors. Previous evidences suggested that Tumor suppressor candidate 7 (TUSC7) was involved in several tumors initiation. However, the role of TUSC7 in colorectal cancer is still unknown. In this study, we indicated that the expression of TUSC7 was downregulated in colorectal cancer cell lines and tissues. Moreover, the expression of TUSC7 was lower in the high-grade (Dukes C and D) colorectal cancer patients compared to that in the low-grade colorectal cancer patients (Dukes A and B). Colorectal cancer patients with a lower level of TUSC7 expression had worse overall survival rate. Elevated expression of TUSC7 suppressed SW480 and HT29 cell proliferation and invasion. In addition, we demonstrated that overexpression of TUSC7 inhibited the expression of miR-10a and enhanced the expression of PTEN and EphA8, which were the direct target genes of miR-10a. Furthermore, the expression of miR-10a was upregulated in colorectal cancer cell lines and tissues. TUSC7 suppressed colorectal cancer cell proliferation and invasion partly through targeting miR-10a. These results suggested that TUSC7 played as a tumor suppressor gene in colorectal cancer partly through inhibiting miR-10a expression.

miR-194 as predictive biomarker of responsiveness to neoadjuvant chemoradiotherapy in patients with locally advanced rectal adenocarcinoma

AIMS

Curative surgery remains the primary form of treatment for locally advanced rectal cancer (LARC). Recent data support the use of preoperative chemoradiotherapy (pCRT) to improve the prognosis of LARC with a significant reduction of local relapse and an increase of overall survival. Unfortunately, only 20% of the patients with LARC present complete pathological response after pCRT, whereas in 20%-40%, the response is poor or absent.

METHODS

We investigated the expression level of miR-194 in n=38 patients with LARC using our public microRNA (miRNA) expression dataset. miR-194 expression was further validated by real-time quantitative PCR (qRT-PCR) and in situ hybridisation (ISH). Protein-protein interaction network and pathway enrichment analysis were performed on miR-194 targets.

RESULTS AND DISCUSSION

Using biopsy samples collected at diagnosis, mir-194 was significantly upregulated in patients responding to treatment (p value=0.016). The data was confirmed with qRT-PCR (p value=0.0587) and ISH (p value=0.026). Protein-protein interaction network and pathway enrichment analysis reveal a possible mechanism of susceptibility to pCRT involving Wnt pathway via its downstream mediator TRAF6. Finally, we interrogated the Comparative Toxicogenomics Database database in order to identify those chemical compounds able to mimic the biological effects of miR-194 as new possible therapeutic option in LARC treatment. The present study combining miRNA expression profiling with integrative computational biology identified miR-194 as predictive biomarker of response to pCRT. Using known and predicted drug mechanism of action, we then identified possible chemical compounds for further in vitro validation.

Upregulation of microRNA-135b and microRNA-182 promotes chemoresistance of colorectal cancer by targeting ST6GALNAC2 via PI3K/AKT pathway

MicroRNAs (miRNAs) are increasingly involved in the development of drug resistance, including 5-fluorouracil (5-FU) resistance in colorectal cancer (CRC). Aberrant sialylation is correlated with human CRC. The study was to explore whether miR-135b and miR-182 modulated 5-FU chemoresistance of CRC by targeting ST6GALNAC2 via PI3K/AKT pathway. MiR-135b and miR-182 were found to be up-regulated in CRC tissues and 5-FU resistant CRC cell lines. Forced miR-135b and miR-182 expression also affected ST6GALNAC2 levels. Using reporter-gene assay, ST6GALNAC2 was identified as direct target of miR-135b and miR-182, while ST6GALNAC2 expression exhibited patterns opposite to that of miR-135b and miR-182 in CRC samples and cell lines. Interestingly, up-regulation of miR-135b or miR-182 increased drug resistance and proliferation, but decreased apoptosis in 5-FU resistant CRC cell lines. Suppression of these miRNAs implicated an inverse function, while altered expression of ST6GALNAC2 mediated CRC progression upon transfection with miR-135b/-182 mimic or inhibitor. Furthermore, miR-135b and miR-182 were clarified to regulate the activity of phosphoinositide-3 kinase (PI3K)/AKT pathway. Inhibition of the PI3K/AKT pathway enhanced the chemosensitivity to 5-FU in HCT-8/5-FU and LoVo/5-FU. Taken together, miR-135b and miR-182 may reverse the resistance to 5-FU in CRC cells by targeting ST6GALNAC2 via PI3K/AKT pathway, which render potential chemotherapy targets for the treatment of CRC.

MicroRNA-761 promotes the sensitivity of colorectal cancer cells to 5-Fluorouracil through targeting FOXM1

Resistance to chemotherapy is a big challenge for treatment of patients with colorectal cancer; however; the mechanism underlying chemoresistance in colorectal cancer cell has not been elucidated. MicroRNAs (miRNAs) are new players in the development of drug chemoresistance. In our study, we indicated that overexpression of miR-761 promoted the sensitivity of colorectal cancer cells to 5-Fluorouracil (5-FU). miR-761 expression was downregulated in colorectal cancer cell lines and tissues. miR-761 expression was lower in patients with low grade than in patients with high grade. In additon, we showed that elevated expression of miR-761 suppressed colorectal cancer cell proliferation, cell cycle, colony formation and cell invasion. We identified that FOXM1 was a direct target gene of miR-761 in colorectal cancer cell. FOXM1 expression was upregulated in colorectal cancer tissues compare to the adjacent non-tumor tissues. MiR-761 expression was negatively associated with the expression of FOXM1 in colorectal cancer tissues. Elevated expression of FOXM1 suppressed the sensitivity of miR-761-overexpressing HT29 cells to 5-FU. We also indicated that FOXM1 overexpression promoted cell proliferation, cycle and invasion of miR-761-overexpressing HT29 cells. These data suggested that miR-761 played a tumor suppressor miRNA in colorectal cancer progression and reduced miR-761 expression might be a major mechanism for 5-FU resistance in colorectal cancer cell.

The role of microRNAs in colorectal liver metastasis: Important participants and potential clinical significances

Colorectal cancer is one of the most common cancers in the world, and liver metastasis is the leading direct cause of cancer-related deaths in colorectal cancer. MicroRNA is involved in tumor metastasis in many aspects; mounting studies have shown that microRNAs play important roles in colorectal liver metastasis. Although lots of reviews about the association between microRNAs and colorectal cancer metastasis have been published, the reviews specifically focusing on microRNAs and colorectal liver metastasis are still lacking in the literature. To address this issue, here, we summarize the underlying mechanisms of microRNAs in colorectal liver metastasis and explore their potential clinical applications in this aspect.

Importance of miR-299-5p in colorectal cancer

Background

MicroRNAs (miRNAs) are effective regulators of gene expression that play a pivotal role in the pathogenesis of colorectal cancer (CRC) and various other cancers. The high prevalence of aberrant miRNA expression in CRC suggests that they can be used as biomarkers and anticancer molecules for therapeutic purposes. There is evidence that microRNA-299-5p (miR-299-5p) is associated with vital cell processes (e.g. epithelial-mesenchymal transition, proliferation, and tumorigenicity) and its improper expression with tumorigenesis in many types of human cancer. This prospective study investigated the contribution of miR-299-5p to CRC tumorigenesis.

Methods

The real-time reverse transcription-polymerase chain reaction was used to examine miR-299-5p expression levels prospectively in 40 sample pairs of CRC tissue and adjacent noncancerous tissue (>2 cm from cancer tissue). The ability of miR-299-5p to function as a tumor marker was also examined.

Results

The expression levels of miR-299-5p were significantly downregulated in the group of CRC samples compared with matched noncancerous tissue samples. No significant relationship was found between miR-299-5p expression levels and clinicopathological features. Receiver operating characteristic analysis gave an area under the curve of 71% for miR-299-5p with 68% sensitivity and 78% specificity (P=0.001).

Conclusion

The miRNA miR-299-5p may be considered as a tumor marker in CRC and could be of assistance as a potential predictive biomarker in the diagnosis of this cancer.

Early miR-223 Upregulation in Gastroesophageal Carcinogenesis

OBJECTIVES

To test miR-223 upregulation during gastric (intestinal-type) and Barrett esophageal carcinogenesis.

METHODS

miR-223 expression was assessed by quantitative reverse transcription polymerase chain reaction in a series of 280 gastroesophageal biopsy samples representative of the whole spectrum of phenotypic changes involved in both carcinogenetic cascades. The results were further validated by in situ hybridization on multiple tissue specimens obtained from six surgically treated gastroesophageal adenocarcinomas. miR-223 expression was also assessed in plasma samples from 30 patients with early stage (ie, stages I and II) gastroesophageal adenocarcinoma and relative controls.

RESULTS

In both gastric and esophageal models, miR-223 expression significantly increased along with the severity of the considered lesions (analysis of variance, P  <   .001). Among atrophic gastritis and long-segment Barrett esophagus samples, miR-223 overexpression was significantly associated with the score of intestinal metaplasia. miR-223 plasma levels were significantly upregulated in patients with cancer compared with controls ( t test, both P  <   .001).

CONCLUSIONS

miR-223 early upregulation observed in tissue samples and its diagnostic value in discriminating patients with early adenocarcinoma by plasma testing provide a solid rationale for further exploring the diagnostic reliability of this microRNA as a novel biomarker in gastroesophageal adenocarcinoma secondary prevention strategies.

Colorectal adenoma and carcinoma specific miRNA profiles in biopsy and their expression in plasma specimens

BACKGROUND

MiRNA expression markers are well characterized in colorectal cancer (CRC), but less is known about miRNA expression profiles in colorectal adenomas. Genome-wide miRNA and mRNA expression analyses were conducted through the colorectal adenoma dysplasia sequence. Furthermore, analysis of the expression levels of miRNAs in matched plasma samples was performed, focusing on biomarker candidates; miRNA and mRNA expression analyses were performed on colorectal biopsies and plasma samples (20 normals; 11 tubular and 9 tubulovillous adenomas; 20 colorectal carcinomas) by miRNA 3.0 and Human Transcriptome Array (Affymetrix) and validated by RT-qPCR. Microarray data were analyzed using Expression Console and mRNA targets were predicted using miRWALK 2.0.

RESULTS

Based on microarray analysis, 447 miRNAs were expressed in tissue and 320 in plasma. Twelve were upregulated (miR-31, 8-fold p < 0.001) and 11 were downregulated (miR-10b 3-fold p < 0.001) in neoplastic lesions compared to normal group. Eleven miRNAs showed altered expression between adenoma subtypes (miR-183 2.8-fold change, p < 0.007). Expression level of 24 miRNAs differed between adenoma and CRC groups (including miR-196a, 3.5-fold). Three miRNAs (miR-31, miR-4506, miR-452*) were differentially expressed in adenoma compared to normal both in tissue and plasma samples. miRNA expression data were confirmed by RT-PCR both in plasma and matched tissue samples.

CONCLUSIONS

MiRNAs showed characteristic expression changes during CRC development in tissue. miRNAs were also presented in plasma and positively correlated with matched tissue expression levels. The identified miRNA expression changes could be verified RT-PCR methods facilitating routine application.

Blood-based microRNAs as biomarkers for the diagnosis of colorectal cancer: a systematic review and meta-analysis

Background:

Colorectal cancer (CRC) is common and associated with significant mortality. Current screening methods for CRC lack patient compliance. microRNAs (miRNAs), identified in body fluids, are negative regulators of gene expression and are dysregulated in many cancers, including CRC. This paper summarises studies identifying blood-based miRNAs dysregulated in CRC compared with healthy controls in an attempt to evaluate their use as a screening tool for the diagnosis of CRC.

Methods:

A search of electronic databases (PubMed and EMBASE) and grey literature was performed between January 2002 and April 2016. Studies reporting plasma or serum miRNAs in the diagnosis of CRC compared with healthy controls were selected. Patient demographics, type of patient sample (serum or plasma), method of miRNA detection, type of normalisation, and the number of significantly dysregulated miRNAs identified were recorded. Statistical evaluation of dysregulated miRNAs using sensitivity, specificity, and area under the curve (AUC) was performed.

Results:

Thirty-four studies investigating plasma or serum miRNAs in the diagnosis of CRC were included. A total of 31 miRNAs were found to be either upregulated (n=17) or downregulated (n=14) in CRC cases as compared with controls. Fourteen studies identified panels of ⩾2 dysregulated miRNAs. The highest AUC, 0.943, was identified using a panel of 4 miRNAs with 83.3% sensitivity and 93.1% specificity. Meta-analysis of studies identifying a single dysregulated miRNA in CRC cases compared with controls was performed. Overall sensitivity and specificity of 28 individual miRNAs in the diagnosis of CRC were 76% (95% CI 72%–80%) and 76% (95% CI 72%–80%), respectively, indicating good discriminative ability of miRNAs as biomarkers for CRC. These data did not change with sensitivity analyses.

Conclusions:

Blood-based miRNAs distinguish patients with CRC from healthy controls with high sensitivity and specificity comparable to other common and invasive currently used screening methods for CRC. In future, miRNAs may be used as a relatively non-invasive blood-based marker for detection of CRC.

MiR-182 promotes cancer invasion by linking RET oncogene activated NF-κB to loss of the HES1/Notch1 regulatory circuit

Background

Dominant-activating mutations in the RET proto-oncogene, a receptor tyrosine kinase, are responsible for the development of medullary thyroid carcinoma (MTC) and causative for multiple endocrine neoplasia (MEN) type 2A and 2B. These tumors are highly aggressive with a high propensity for early metastasis and chemoresistance. This attribute makes this neoplasia an excellent model for probing mechanisms underlying cancer progression.

Methods

The expression level of miR-182 was measured in MTC tumor specimens and in TT cells by real-time RT-PCR. TT cells and modified NThy-ori 3.1 that stably express RETM918T were used to investigate RET-dependent regulation of miR-182. Identification and validation of miR-182 targets and pathways was accomplished with luciferase assays, qRT-PCR, Western blotting and immunofluorescence. In vitro, overexpression and knockdown experiments were carried out to examine the impact of miR-182 and HES1 on invasion and migration.

Results

We found that miR-182 expression is significantly upregulated in MTC patient samples and tumor-derived cell lines harboring mutated RET. Inhibition of RET oncogenic signaling through a dominant-negative RET∆TK mutant in TT cells reduces miR-182, whereas overexpression of RETM918T in NThy-ori 3.1 cells increases miR-182 levels. We further show that overexpression of this miRNA in NThy.miR-182 cells promotes the invasive and migratory properties without affecting cell proliferation. MiR-182 is upregulated after RET induced NF-κB translocation into the nucleus via binding of NF-κB to the miR-182 promoter. Database analysis revealed that HES1, a repressor of the Notch pathway, is a target of miR-182, whose upregulation correlates with loss of HES1 transcription in MTC tissue samples and mutant RET cell lines. Moreover, we demonstrated that the 3′UTR of the HES1 mRNA bearing the targeting sequence for miR-182 clearly reduced luciferase reporter activity in cells expressing miR-182. Decreased expression of HES1 promotes migration by upregulating Notch1 inhibitor Deltex1 and consequent repression of Notch1.

Conclusion

We demonstrate a novel mechanism for MTC aggressiveness in which mutated RET/NF-κB-driven expression of miR-182 impedes HES1 activation in a negative feedback loop. This observation might open new possibilities to treat RET oncogene associated metastatic cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-016-0563-x) contains supplementary material, which is available to authorized users.

Gene and MicroRNA Expression Are Predictive of Tumor Response in Rectal Adenocarcinoma Patients Treated With Preoperative Chemoradiotherapy

Preoperative chemoradiotherapy (pCRT) followed by surgery is the standard treatment for locally advanced rectal cancer (LARC). However, tumor response to pCRT is not uniform, and there are no effective predictive methods. This study investigated whether specific gene and miRNA expression are associated with tumor response to pCRT. Tissue biopsies were obtained from patients before pCRT and resection. Gene and miRNA expression were analyzed using a one-color microarray technique that compares signatures between responders (R) and non-responders (NR), as measured based on tumor regression grade. Two groups composed of 38 "exploration cohort" and 21 "validation cohort" LARC patients were considered for a total of 32 NR and 27 R patients. In the first cohort, using SAM Two Class analysis, 256 genes and 29 miRNAs that were differentially expressed between the NR and R patients were identified. The anti-correlation analysis showed that the same 8 miRNA interacted with different networks of transcripts. The miR-630 appeared only with the NR patients and was anti-correlated with a single transcript: RAB5B. After PAM, the following eight transcripts were strong predictors of tumor response: TMEM188, ITGA2, NRG, TRAM1, BCL2L13, MYO1B, KLF7, and GTSE1. Using this gene set, an unsupervised cluster analysis was applied to the validation cohort and correctly assigned the patients to the NR or R group with 85.7% accuracy, 90% sensitivity, and 82% specificity. All three parameters reached 100% when both cohorts were considered together. In conclusion, gene and miRNA expression profiles may be helpful for predicting response to pCRT in LARC patients. J. Cell. Physiol. 232: 426-435, 2017. © 2016 Wiley Periodicals, Inc.

miR-182-5p Induced by STAT3 Activation Promotes Glioma Tumorigenesis

Malignant glioma is an often fatal type of cancer. Aberrant activation of STAT3 leads to glioma tumorigenesis. STAT3-induced transcription of protein-coding genes has been extensively studied; however, little is known about STAT3-regulated miRNA gene transcription in glioma tumorigenesis. In this study, we found that abnormal activation or decreased expression of STAT3 promotes or inhibits the expression of miR-182-5p, respectively. Bioinformatics analyses determined that tumor suppressor protocadherin-8 (PCDH8) is a candidate target gene of miR-182-5p. miR-182-5p negatively regulated PCDH8 expression by directly targeting its 3'-untranslated region. PCDH8 knockdown induced the proliferative and invasive capacities of glioma cells. Silencing of PCDH8 or miR-182-5p mimics could reverse the inhibitory effect of WP1066, a STAT3 inhibitor, or STAT3 knockdown in vitro and in vivo on glioma progression. Clinically, expression levels of PCDH8 were inversely correlated with those of p-STAT3 or miR-182-5p in glioblastoma tissues. These findings reveal that the STAT3/miR-182-5p/PCDH8 axis has a critical role in glioma tumorigenesis and that targeting the axis may provide a new therapeutic approach for human glioma. Cancer Res; 76(14); 4293-304. ©2016 AACR.

New trends in molecular and cellular biomarker discovery for colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer death worldwide, which is consequence of multistep tumorigenesis of several genetic and epigenetic events. Since CRC is mostly asymptomatic until it progresses to advanced stages, the early detection using effective screening approaches, selection of appropriate therapeutic strategies and efficient follow-up programs are essential to reduce CRC mortalities. Biomarker discovery for CRC based on the personalized genotype and clinical information could facilitate the classification of patients with certain types and stages of cancer to tailor preventive and therapeutic approaches. These cancer-related biomarkers should be highly sensitive and specific in a wide range of specimen(s) (including tumor tissues, patients’ fluids or stool). Reliable biomarkers which enable the early detection of CRC, can improve early diagnosis, prognosis, treatment response prediction, and recurrence risk. Advances in our understanding of the natural history of CRC have led to the development of different CRC associated molecular and cellular biomarkers. This review highlights the new trends and approaches in CRC biomarker discovery, which could be potentially used for early diagnosis, development of new therapeutic approaches and follow-up of patients.

Aberrant plasma levels of circulating miR-16, miR-107, miR-130a and miR-146a are associated with lymph node metastasis and receptor status of breast cancer patients

Within the multicenter SUCCESS trial, we investigated the association of plasma microRNAs with different subtypes of invasive breast cancer.

Six miRs (miR-16, miR-27a, miR-107, miR-130a, miR-132 and miR-146a) were selected from microarray profiling and further validated in plasma of 111 breast cancer patients before and after chemotherapy and 46 healthy women by quantitative real-time PCR.

Plasma levels of miR-16 (p = 0.0001), miR-27a (p = 0.039) and miR-132 (p = 0.020) were higher in breast cancer patients before chemotherapy than healthy women. With the exception of miR-16, the increased levels of miR-27a (p = 0.035) and miR-132 (p = 0.025) decreased after chemotherapy to those observed in healthy women. Levels of miR-16 (p = 0.019), miR-107 (p = 0.036), miR-130a (p = 0.027) and miR-146a (p = 0.047) were different between lymph node -positive and -negative patients, while the levels of miR-130a (p = 0.001) and miR-146a (p = 0.025) also differed between HER2-positive and -negative status. Estrogen-receptor negative tumors displayed higher concentrations of circulating miR-107 than their counterparts (p = 0.035). However, overexpression of miR-107 in MCF-7 cells did not downregulate estrogen receptor protein. Altered expression levels of miR-107 influenced the migration and invasion behavior of MCF-7 and MDA-MB-231 cells.

Our data indicate differential concentrations of plasma miR-16, miR-107, miR-130a and miR-146a in different breast cancer subtypes, suggesting a potential role of these miRs in breast cancer biology and tumor progression.

miR-191 promotes tumorigenesis of human colorectal cancer through targeting C/EBPβ

MicroRNA-191 (miR-191), a small non-coding RNA, is involved in disease development and cancer diagnosis and prognosis. However, how miR-191 functions in colorectal cancer remains largely unclear. In this study, we show that miR-191 is highly expressed in colon tumor tissues, and that inhibition of miR-191 leads to decreased cell growth, proliferation and tumorigenicity in a xenograft model. Overexpression of miR-191 in colorectal cancer cell lines alters cell cycle progression and cell resistance to 5-Fu induced cell apoptosis. Mechanistic studies demonstrated that miR-191 directly binds to the 3′UTR of the C/EBPβ mRNA and mediates a decrease in the mRNA and protein expression of C/EBPβ. We further showed that C/EBPβ induces growth arrest in a colorectal cancer cell line and that its expression is negatively correlated with the miR-191 level in patient samples. Our findings suggest that miR-191 may be a potential gene therapy target for the treatment of colorectal cancer.

MicroRNAs as growth regulators, their function and biomarker status in colorectal cancer

Gene expression is in part regulated by microRNAs (miRNAs). This review summarizes the current knowledge of miRNAs in colorectal cancer (CRC); their role as growth regulators, the mechanisms that regulate the miRNAs themselves and the potential of miRNAs as biomarkers. Although thousands of tissue samples and bodily fluids from CRC patients have been investigated for biomarker potential of miRNAs (>160 papers presented in a comprehensive tables), none single miRNA nor miRNA expression signatures are in clinical use for this disease. More than 500 miRNA-target pairs have been identified in CRC and we discuss how these regulatory nodes interconnect and affect signaling pathways in CRC progression.

Let-7c down-regulation in Helicobacter pylori-related gastric carcinogenesis

Aberrant let-7c microRNA (miRNA) expression has been observed in Helicobacter pylori-related gastric cancer (GC) but fragmentary information is available on the let-7c dysregulation occurring with each phenotypic change involved in gastric carcinogenesis. Let-7c expression was assessed (qRT-PCR) in a series of 175 gastric biopsy samples representative of the whole spectrum of phenotypic changes involved in H. pylori-related gastric oncogenesis including: i) normal gastric mucosa, as obtained from dyspeptic controls (40 biopsy samples); ii) non-atrophic gastritis (40 samples); iii) atrophic-metaplastic gastritis (35 samples); iv) intra-epithelial neoplasia (30 samples); v) GC (30 samples). Let-7c expression was also tested in 20 biopsy samples obtained from 10 patients before and after H. pylori eradication therapy (median follow-up: 10 weeks; range: 7-14). The results obtained were further validated by in situ hybridization on multiple tissue specimens obtained from 5 surgically treated H. pylori-related GCs. The study also included 40 oxyntic biopsy samples obtained from serologically/histologically confirmed autoimmune gastritis (AIG: 20 corpus-restricted, non-atrophic; 20 corpus-restricted, atrophic-metaplastic). Let-7c expression dropped from non-atrophic gastritis to atrophic-metaplastic gastritis, intra-epithelial neoplasia, and invasive GC (p<0.001). It rose again significantly following H. pylori eradication (p=0.009). As in the H. pylori model, AIG also featured a significant let-7c down-regulation (p<0.001). The earliest phases of the two pathways to gastric oncogenesis (H. pylori-environmental and autoimmune host-related) are characterized by similar let-7c dysregulations. In H. pylori infection, let-7c down-regulation regresses after the bacterium's eradication, while it progresses significantly with the increasing severity of the histological lesions.

miR-488 acts as a tumor suppressor gene in gastric cancer

MicroRNAs (miRNAs) are small, non-coding RNAs that modulate development, cell proliferation, and apoptosis. The deregulated expression of microRNAs is found in carcinogenesis including gastric cancer (GC). In this study, we showed that the expression levels of miR-488 were downregulated in GC tissues compared to in non-tumor tissues. In addition, the expression of miR-488 was also lower in GC cell lines in contrast with the gastric epithelial cell line (GES). In addition, the expression level of miR-488 was negatively correlated with the TNM stage in GC patients, and lower miR-488 expression was found in tumors with advanced TNM stage. The ectopic expression of miR-488 suppressed the GC cell proliferation, cell cycle, colony information, and migration. PAX6 was identified as a direct target gene of miR-488 in HGC-27. Moreover, we found that the expression level of PAX6 was upregulated in the GC tissues compared with the non-tumor tissues. The PAX6 expression level was correlated with the cancer TNM stage, and higher PAX6 expression was found in tumors with advanced TNM stage. Furthermore, there was an inverse correlation between PAX6 and miR-488 expression levels in GC tissues. Therefore, these studies demonstrated that miR-488 might act as a tumor suppressor miRNA in the development of GC.

Circulating lncRNAs associated with occurrence of colorectal cancer progression

Screening for the potential biomarker of colorectal cancer (CRC) is necessary to improve the early detection. The aim of this study was to investigate the potential of circulating cell-free long non-coding RNAs (lncRNA) as biomarkers of CRC. In this study, we applied an lncRNA microarray to screen the potential biomarker for CRC with a multi-stage validation and risk score formula detection. We discovered three lncRNA, XLOC_006844, LOC152578 and XLOC_000303, which were up-regulated in CRC comparing with the cancer-free controls with the merged area under curve (AUC) in training set and validation set of 0.919 and 0.975. The three lncRNAs might be the potential biomarker for the tumorigenesis prediction of CRC in the future.

The Downregulation of MiR-182 Is Associated with the Growth and Invasion of Osteosarcoma Cells through the Regulation of TIAM1 Expression

Background

Osteosarcoma is the most common primary bone malignancy in children and young adults. Increasing results suggest that discovery of microRNAs (miRNAs) might provide a novel therapeutical target for osteosarcoma.

Methods

MiR-182 expression level in osteosarcoma cell lines and tissues were assayed by qRT-PCR. MiRNA mimics or inhibitor were transfected for up-regulation or down-regulation of miR-182 expression. Cell function was assayed by CCK8, migration assay and invasion assay. The target genes of miR-182 were predicated by bioinformatics algorithm (TargetScan Human).

Results

MiR-182 was down-regulated in osteosarcoma tissues and cell lines. Overexpression of miR-182 inhibited tumor growth, migration and invasion. Subsequent investigation revealed that TIAM1 was a direct and functional target of miR-182 in osteosarcoma cells. Overexpression of miR-182 impaired TIAM1-induced inhibition of proliferation and invasion in osteosarcoma cells.

Conclusions

Down-expression of miR-182 in osteosarcoma promoted tumor growth, migration and invasion by targeting TIAM1. MiR-182 might act as a tumor suppressor gene whose down-regulation contributes to the progression and metastasis of osteosarcoma, providing a potential therapy target for osteosarcoma patients.

MiR-144 Inhibits Uveal Melanoma Cell Proliferation and Invasion by Regulating c-Met Expression

MicroRNAs (miRNAs) are a group endogenous small non-coding RNAs that inhibit protein translation through binding to specific target mRNAs. Recent studies have demonstrated that miRNAs are implicated in the development of cancer. However, the role of miR-144 in uveal melanoma metastasis remains largely unknown. MiR-144 was downregulated in both uveal melanoma cells and tissues. Transfection of miR-144 mimic into uveal melanoma cells led to a decrease in cell growth and invasion. After identification of two putative miR-144 binding sites within the 3' UTR of the human c-Met mRNA, miR-144 was proved to inhibit the luciferase activity inMUM-2B cells with a luciferase reporter construct containing the binding sites. In addition, the expression of c-Met protein was inhibited by miR-144. Furthermore, c-Met-mediated cell proliferation and invasion were inhibited by restoration of miR-144 in uveal melanoma cells. In conclusion, miR-144 acts as a tumor suppressor in uveal melanoma, through inhibiting cell proliferation and migration. miR-144 might serve as a potential therapeutic target in uveal melanoma patients.

miR-454 is down-regulated in osteosarcomas and suppresses cell proliferation and invasion by directly targeting c-Met

OBJECTIVES

Osteosarcoma is the most common primary bone malignancy of children and young adults. Increasing evidence has shown that microRNAs (miRNAs) are associated with cancer development, but, little is known concerning the role of miR-454 in osteosarcoma.

MATERIALS AND METHODS

qRT-PCR was performed to detect expression of miR-454 in osteosarcoma cell lines and tissues. To understand its role in osteosarcoma, we reintroduced expression of miR-454 in the MG-63 cell line by transfection with miR-454 mimics or inhibitors. CCK-8 assay and an invasion assay were used to detect the functional role of miR-454. Luciferase assay and western blot analysis were performed to detect the target gene of miR-454.

RESULTS

miR-454 was found to be down-regulated in osteosarcoma tissues and cell lines. Its over-expression inhibited tumour growth and invasion and its down-regulation promoted cell proliferation and invasion. Subsequent investigation revealed that c-Met was a direct and functional target of miR-454 in osteosarcoma. Overexpression of miR-454 impaired c-Met-induced cell proliferation and invasion. Finally, miR-454 was found to be inversely correlated to c-Met expression in human osteosarcoma tissues.

CONCLUSIONS

Reduced-expression of miR-454 in osteosarcoma cells promoted tumour growth by targeting c-Met, thus miR-454 may be a potential therapy target for this tumour.