Circulating microRNAs in serum: novel biomarkers for patients with bladder cancer?

Natural and Synthetic Progestins Increase Transcriptional Expression of primiR-190 and primiR-199 in T47D Breast Cancer Cells: A Preliminary Study

Background Previous studies have shown that aberrant expression of different microRNAs potentially contributes to carcinogenesis, growth, and metastasis of several human cancers. Given that progestins have been reported to alter the expression of microRNAs in various human cancers, we hypothesized that progestins potentially influence the growth of hormone-responsive breast cancer through mechanisms involving the regulation of miRNAs functioning either as tumor suppressors or oncogenes. Using computer-based analysis, we identified two microRNAs that we investigated in this study, namely miR-190 and miR-199. Our main objective in this preliminary study was to determine the effect of different progestins on the expression of these two microRNAs in breast cancer cells. Methods Progesterone receptor (PR)-positive cell line, T47D breast cancer cells were exposed to progesterone and three different synthetic progestins for 24 hours, after which RNA was extracted and real-time polymerase chain reaction (PCR) was used to determine the expression of primiR-190 and primiR-199. For comparison, progestin effects were also tested in T47Dco-Y, a PR-negative cell line. Results Our results showed exposing T47D cells to both progesterone and synthetic progestins increased the transcriptional expression of primiR-190 and primiR-199a1 by as high as four to seven fold (P<0.0001). RU-486, a progesterone receptor antagonist, suppressed progestin induction of both primiR-190 and primiR-199a1. Progestin-induced effects were not observed in a PR-negative subline of T47D cells (P>0.05), further confirming the involvement of progesterone receptor-dependent pathways. Additionally, 17β estradiol and dimethyl sulfoxide did not alter the expression of both primiR-190 and primiR-199a1. Conclusion Different progestins increase transcriptional expression of both primiR-190 and primiR-199a-1 through progesterone receptor (PR)-dependent mechanisms. Both primiR-190 and primiR-199a1 can potentially be useful as biomarkers for PR-positive breast cancer.

Amplification-Free Analysis of Bladder Cancer MicroRNAs on Wrinkled Silica Nanoparticles with DNA-Functionalized Quantum Dots

Bladder cancer (BC) occurrence and progression are accompanied by alterations in microRNAs (miRNAs) expression levels. Simultaneous detection of multiple miRNAs contributes to the accuracy and reliability of the BC diagnosis. In this work, wrinkled silica nanoparticles (WSNs) were applied as the microreactor for multiplex miRNAs analysis without enzymes or nucleic acid amplification. Conjugated on the surface of WSNs, the S9.6 antibody was adopted as the universal module for binding DNA/miRNA duplexes, regardless of their sequence. Furthermore, single-stranded DNA (ssDNA) was labeled with quantum dots (QDs) for identifying a given miRNA to form QDs-ssDNA/miRNA, which enabled the specific capture of the corresponding QDs on the wrinkled surface of WSNs. Based on the detection of fluorescence signals that were ultimately focused on WSNs, target miRNAs could be sensitively identified to a femtomolar level (5 fM) with a wide dynamic range of up to 6 orders of magnitude. The proposed strategy achieved high specificity to obviously distinguish single-base mutation sequences and possessed multiplex assay capability. Moreover, the assay exhibited excellent practicability in the multiplex detection of miRNAs in clinical serum specimens.

Liquid biopsy in urothelial carcinoma: Detection techniques and clinical applications

The types of urothelial carcinoma (UC) include urothelial bladder cancer and upper tract urothelial carcinoma. Current diagnostic techniques cannot meet the needs of patients. Liquid biopsy is an accurate method of determining the molecular profile of UC and is a cutting-edge and popular technique that is expected to complement existing detection techniques and benefit patients with UC. Circulating tumor cells, cell-free DNA, cell-free RNA, extracellular vesicles, proteins, and metabolites can be found in the blood, urine, or other bodily fluids and are examined during liquid biopsies. This article focuses on the components of liquid biopsies and their clinical applications in UC. Liquid biopsies have tremendous potential in multiple aspects of precision oncology, from early diagnosis and treatment monitoring to predicting prognoses. They may therefore play an important role in the management of UC and precision medicine.

Mir-183 functions as an oncogene via decreasing PTEN in breast cancer cells

Regarding the important role of microRNAs in breast cancer, investigating the molecular mechanisms of miRs and their impacts on breast cancer progression is critical. Thus, the present work aimed to investigate the molecular mechanism of miR-183 in breast cancer. PTEN was validated by dual luciferase assay as a target gene of miR-183. Through qRT-PCR analysis, miR-183 and PTEN mRNA levels in breast cancer cell lines were measured. To determine the impacts of miR-183 on cell viability, the MTT assay was used. Moreover, flowcytometry was applied to analyze the effects of miR-183 on the cell cycle progression. To detect the effects of miR-183 on the migration of BC cell lines, wound healing was used along with a Trans-well migration assay. Western blot was utilized to assess the effect of miR-183 on PTEN protein expression. MiR-183 can exert an oncogenic effect by promoting cell viability, migration, and cell cycle progression. It was revealed that cellular oncogenicity is positively regulated by miR-183 by inhibiting the expression of PTEN. According to the present data, miR-183 may play a vital role in the progression of breast cancer by reducing PTEN expression. It may be also a potential therapeutic target for this disease.

The miR-200 Family of microRNAs: Fine Tuners of Epithelial-Mesenchymal Transition and Circulating Cancer Biomarkers

The miR-200 family of microRNAs (miRNAs) includes miR-200a, miR-200b, miR-200c, miR-141 and miR-429, five evolutionarily conserved miRNAs that are encoded in two clusters of hairpin precursors located on human chromosome 1 (miR-200b, miR-200a and miR-429) and chromosome 12 (miR-200c and miR-141). The mature -3p products of the precursors are abundantly expressed in epithelial cells, where they contribute to maintaining the epithelial phenotype by repressing expression of factors that favor the process of epithelial-to-mesenchymal transition (EMT), a key hallmark of oncogenic transformation. Extensive studies of the expression and interactions of these miRNAs with cell signaling pathways indicate that they can exert both tumor suppressor- and pro-metastatic functions, and may serve as biomarkers of epithelial cancers. This review provides a summary of the role of miR-200 family members in EMT, factors that regulate their expression, and important targets for miR-200-mediated repression that are involved in EMT. The second part of the review discusses the potential utility of circulating miR-200 family members as diagnostic/prognostic biomarkers for breast, colorectal, lung, ovarian, prostate and bladder cancers.

miR-190a-3p Promotes Proliferation and Migration in Glioma Cells via YOD1

INTRODUCTION

To investigate the function of miR-190a-3p on the proliferation and migration of glioma.

METHODS

Twenty glioma samples and 6 normal brain tissue samples were collected. Normal human glial cell line HEB and glioma cell lines were used for the experiments. We then used TargetScan to predict the target genes of miR-190a-3p. Dual-luciferase reporter assay was also used to validate.

RESULTS

Combined with dual-luciferase reporter experiment, we finally verified that YOD1 was the aim, and it was low-expressed in glioma. Besides, a series of mechanism experiments then proved that miR-190a-3p negatively regulates YOD1 expression.

CONCLUSIONS

Our research was the first to demonstrate the promoting function of miR-190a-3p in the proliferation and migration of glioma and provided new views for the treatment of glioma. miR-190a-3p was expected to be a new target for molecular therapy of glioma.

Snail Overexpression Alters the microRNA Content of Extracellular Vesicles Released from HT29 Colorectal Cancer Cells and Activates Pro-Inflammatory State In Vivo

Simple Summary

Knowledge of the factors that help migration of carcinoma cells is important for prevention of metastasis. Cancer cells release small particles, extracellular vesicles (EVs) that contain such factors. The aim of this study was to assess if the content of EVs changes through different stages of colorectal cancer (CRC) and evaluate how this process affects cancer progression in vivo in mouse CRC model. We found that EVs released from cells that have migratory properties contain different factors then EVs released from original tumor cells. We also show here that EVs can be incorporated into other cells that facilitate metastasis and change their properties depending on the EVs content. The content of cell-released EVs may also serve as a biomarker that denotes the stage of CRC and may be a target to prevent cancer progression.

Abstract

During metastasis, cancer cells undergo phenotype changes in the epithelial-mesenchymal transition (EMT) process. Extracellular vesicles (EVs) released by cancer cells are the mediators of intercellular communication and play a role in metastatic process. Knowledge of factors that influence the modifications of the pre-metastatic niche for the migrating carcinoma cells is important for prevention of metastasis. We focus here on how cancer progression is affected by EVs released from either epithelial-like HT29-cells or from cells that are in early EMT stage triggered by Snail transcription factor (HT29-Snail). We found that EVs released from HT29-Snail, as compared to HT29-pcDNA cells, have a different microRNA profile. We observed the presence of interstitial pneumonias in the lungs of mice injected with HT29-Snail cells and the percent of mice with lung inflammation was higher after injection of HT29-Snail-EVs. Incorporation of EVs released from HT29-pcDNA, but not released from HT29-Snail, leads to the increased secretion of IL-8 from macrophages. We conclude that Snail modifications of CRC cells towards more invasive phenotype also alter the microRNA cargo of released EVs. The content of cell-released EVs may serve as a biomarker that denotes the stage of CRC and EVs-specific microRNAs may be a target to prevent cancer progression.

Resveratrol, curcumin, paclitaxel and miRNAs mediated regulation of PI3K/Akt/mTOR pathway: go four better to treat bladder cancer

Bladder cancer (BC) is a leading cause of death among urothelial malignancies that more commonly affect male population. Poor prognosis and resistance to chemotherapy are the two most important characteristics of this disease. PI3K/Akt/mTOR signaling pathway has been considered pivotal in the regulation of proliferation, migration, invasiveness, and metastasis. Deregulation of PI3K/Akt/mTOR signaling has been found in 40% of bladder cancers. Several microRNAs (miRNAs) have been reported to interact with the PI3K/Akt/mTOR signaling pathway with a different possible role in proliferation and apoptosis in bladder cancer. Thus, miRNAs can be used as potential biomarkers for BC. Natural compounds have been in the spotlight for the past decade due to their effective anti-proliferative capabilities. However, little is known of its possible effects in bladder cancer. The aim of this review is to discuss the interplay between PI3K/Akt/mTOR, miRNAs, and natural compounds and emphasize the importance of miRNAs as biomarkers and resveratrol, curcumin and paclitaxel as a possible therapeutic approach against bladder cancer.

cfRNAs as biomarkers in oncology - still experimental or applied tool for personalized medicine already?

Currently, the challenges of contemporary oncology are focused mainly on the development of personalized medicine and precise treatment, which could be achieved through the use of molecular biomarkers. One of the biological molecules with great potential are circulating free RNAs (cfRNAs) which are present in various types of body fluids, such as blood, serum, plasma, and saliva. Also, different types of cfRNA particles can be distinguished depending on their length and function: microRNA (miRNA), PIWI-interacting RNA (piRNA), tRNA-derived RNA fragments (tRFs), circular RNA (circRNA), long non-coding RNA (lncRNA), and messenger RNA (mRNA). Moreover, cfRNAs occur in various forms: as a free molecule alone, in membrane vesicles, such as exosomes, or in complexes with proteins and lipids. One of the modern approaches for monitoring patient's condition is a "liquid biopsy" that provides a non-invasive and easily available source of circulating RNAs. Both the presence of specific cfRNA types as well as their concentration are dependent on many factors including cancer type or even reaction to treatment. Despite the possibility of using circulating free RNAs as biomarkers, there is still a lack of validated diagnostic panels, defined protocols for sampling, storing as well as detection methods. In this work we examine different types of cfRNAs, evaluate them as possible biomarkers, and analyze methods of their detection. We believe that further research on cfRNA and defining diagnostic panels could lead to better and faster cancer identification and improve treatment monitoring.

Good or not good: Role of miR-18a in cancer biology

miR-18a is a member of primary transcript called miR-17-92a (C13orf25 or MIR17HG) which also contains five other miRNAs: miR-17, miR-19a, miR-20a, miR-19b and miR-92a. This cluster as a whole shows specific characteristics, where miR-18a seems to be unique. In contrast to the other members, the expression of miR-18a is additionally controlled and probably functions as its own internal controller of the cluster. miR-18a regulates many genes involved in proliferation, cell cycle, apoptosis, response to different kinds of stress, autophagy and differentiation. The disturbances of miR-18a expression are observed in cancer as well as in different diseases or pathological states. The miR-17-92a cluster is commonly described as oncogenic and it is known as 'oncomiR-1', but this statement is a simplification because miR-18a can act both as an oncogene and a suppressor. In this review we summarize the current knowledge about miR-18a focusing on its regulation, role in cancer biology and utility as a potential biomarker.

Multiparameter urine analysis for quantitative bladder cancer surveillance of orthotopic xenografted mice

The human-derived orthotopic xenograft mouse model is an effective platform for performing in vivo bladder cancer studies to examine tumor development, metastasis, and therapeutic effects of drugs. To date, the surveillance of tumor progression in real time for orthotopic bladder xenografts is highly dependent on semi-quantitative in vivo imaging technologies such as bioluminescence. While these imaging technologies can estimate tumor progression, they are burdened with requirements such as anesthetics, specialized equipment, and genetic modification of the injected cell line. Thus, a convenient and non-invasive technology to quantitatively monitor the growth of bladder cancer in orthotopic xenografts is highly desired. In this work, using a microfluidic chemiluminescent ELISA platform, we have successfully developed a rapid, multiparameter urine-based and non-invasive biomolecular prognostic technology for orthotopic bladder cancer xenografts. This method consists of two steps. First, the concentrations of a panel of four urinary biomarkers are quantified from the urine of mice bearing orthotopic bladder xenografts. Second, machine learning and principal component analysis (PCA) algorithms are applied to analyze the urinary biomarkers, and subsequently, a score is assigned to indicate the tumor growth. With this methodology, we have quantitatively monitored the orthotopic growth of human bladder cancer that was inoculated with low, medium, and high cancer cell numbers. We also employed this method and performed a proof of principle experiment to examine the in vivo therapeutic efficacy of the EGFR inhibitor, dacomitinib.

The potential mechanism of miR-130b on promotion of the invasion and metastasis of hepatocellular carcinoma by inhibiting Notch-Dll1

Introduction: This study aimed to elucidate the regulatory role and molecular regulation mechanism of miR-130b gene in the process of invasion and metastasis of hepatocarcinoma, and provide a theoretical basis for seeking of effective prevention and treatment of new targets for hepatocellular carcinoma.Materials and methods: The expression level of miR-130b gene in hepatocarcinoma tissues was determined by qRT-PCR. The biological function and mechanism of miR-130b gene were verified by cell and animal models, and the target gene was verified by double luciferase assay.Results: In the liver cancer tissues of patients with metastasis, the expression level of miR-130b gene was increased, and the difference was significantly significant (p < 0.05). Evaluation of independent risk factors for overall survival showed significant difference (p < 0.01). Up-regulation of miR-130b in MHCC97L- subpopulation cells significantly enhanced the invasion and migration ability, and the difference was statistically significant (p < 0.05). The invasion and migration ability of MHCC97H + subpopulation cells with increased expression of miR-130b was significantly decreased, and the difference was notably significant (p < 0.05). When the expression of miR-130b in MHCC97H + subpopulation cells was inhibited, the expressions of Notch-Dll1 and SOX2, Nanog and E2F3 proteins in transplanted tumor tissues were significantly higher than those in other groups (p < 0.05). When miR-130b in MHCC97L- subpopulation cells was up-regulated, the expressions of Notch-Dll1 and Bcl-2, CCND1, Nanog and MET proteins in transplanted tumor tissues were significantly increased than those in other groups (p < 0.05). The prediction results of bioinformatics data suggest that the target gene of miR-130b may be Notch-Dll1 gene. The experiment of luciferase reporter gene confirmed that miR-130b gene can be inhibited and contains fluorescent reporter gene with complementary binding site, lost activity.Conclusion: The miR-130b gene can inhibit the protein expression of Notch-Dll1, and it can promote the invasion and metastasis of liver cancer cells.

Tunneling Nanotubes Mediated microRNA-155 Intercellular Transportation Promotes Bladder Cancer Cells' Invasive and Proliferative Capacity

Objective

To investigate differential microRNAs' expression in heterogeneous bladder cancer cells, as well as to investigate the mechanism of changes in invasive and proliferative capacity induced by tunneling nanotubes (TNTs) mediated transport of microRNA between bladder cancer cells of varying histological grade.

Materials and methods

Differences in microRNA expression between bladder cancer cells of different grade were identified from a literature review. The identified heterogeneous microRNAs were analyzed by qPCR in T24 (high grade) and RT4 (low grade) bladder cancer cells. Scanning electron microscopy (SEM) and laser confocal fluorescence microscopy (LCM) were used to observe tunneling nanotubes (TNTs) between RT4 and T24 cells. Differentially expressed microRNA was labeled and traced by Fluorescent In Situ Hybridization (FISH) following co-culture of T24 and RT4 cells. MicroRNA mimic and inhibition technologies were applied to investigate how TNTs-mediated intercellular transport of microRNA affects the invasive and proliferative behavior of bladder cancer cells.

Results

MicroRNA-155 (miR-155) levels were highly expressed in T24 cells, whereas the same was not true in RT4 cells. MiR-155 was confirmed to be a crucial factor sustaining T24 bladder cancer cell proliferation, migration and cell cycle progression by CCK8, Matrigel test and cell cycle analysis, respectively. After T24 and RT4 co-culture, TNTs were assessed by SEM and LCM between T24 and RT4 cells. In addition, we observed TNTs mediated transport of miR-155 from T24 cells to RT4 cells, which thereby acquired a higher proliferative rate, an increased frequency of cells in the S phase, and increased invasive ability in Matrigel test. At the same time, Deptor, the target protein of miR-155 in RT4 cells, was downregulated, followed by mTOR/4EBP1/p70S6K- eIF4e/S6RP signaling activation.

Conclusion

MiR-155 was differentially expressed between RT4 and T24 bladder cancer cells. Intercellular transport of miR-155 via TNTs can promote bladder cancer cell reprogramming by Deptor-mTOR signal pathway activation.

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Retracted Article: Exosome-derived PTENP1 suppresses cisplatin resistance of bladder cancer (BC) by suppressing cell proliferation, migration and inducing apoptosis via the miR-103a/PDCD4 axis

Bladder cancer (BC) is a lethal cancer that threatens the health of millions of people. Chemotherapy drug resistance, for example, cisplatin (DDP) resistance, is a huge limitation for BC therapy. PTEN pseudogene-1 (PTENP1) has been identified as a significant biomarker of multiple cancers. Therefore, it is essential to illuminate the molecular mechanism of PTENP1 in BC cell DDP resistance and progression. Serum exosomes were isolated using an ExoQuick precipitation kit. Serum exosomes were round-shaped vesicles of 100 ± 60 nm in size. The expression of PTENP1 was down-regulated in serum exosomes isolated from cisplatin non-responsive patients compared with responsive patients. ROC curves certified the diagnostic value of PTENP1. Apparently, PTENP1 transfection inhibited DDP-resistant BC cell proliferation, migration, cisplatin resistance and facilitated apoptosis. Next, we discovered that PTENP1 was a sponge of miR-103a, while PDCD4 was a target of miR-103a. More importantly, PTENP1 regulated DDP-resistant cell viability, migration, apoptosis and cisplatin resistance by interacting with the miR-103a/PDCD4 axis. In addition, PTENP1 hindered tumor growth of cisplatin-resistant mice. Exosome-derived PTENP1 suppressed the DDP resistance of BC by inhibiting cell proliferation, migration and promoting apoptosis through regulating the miR-103a/PDCD4 axis, representing a targeted therapy for DDP-resistant BC patients.

miR-190-5p in human diseases

miRNAs, a major class of small noncoding RNAs approximately 18-25 nucleotides in length, function by repressing the expression of target genes through binding to complementary sequences in the 3'-UTRs of target genes. Emerging evidence has highlighted their important roles in numerous diseases, including human cancers. Recently, miR-190 has been shown to be dysregulated in various types of human cancers that participates in cancer-related biological processes, including proliferation, apoptosis, metastasis, drug resistance, by regulating associated target genes, and to predict cancer diagnosis and prognosis. In this review, we summarized the roles of miR-190-5p in human diseases, especially in human cancers. Then we classified its target genes in tumorigenesis and progression, which might provide evidence for cancer diagnosis and prognosis, promising tools for cancer treatment, or leads for further investigation.

Increased expression of miR-601 is associated with poor prognosis and tumor progression of gastric cancer

Background

MicroRNAs (miRNAs) have been considered to participate in many tumorigenesis, including gastric cancer (GC). Abnormal expression of miR-601 has been reported in GC, but its role is not clear. The goal of this study is to explore the expression patterns, clinical value and functional role of miR-601 in GC.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to evaluate the expression level of miR-601. The association between miR-601 expression and overall survival was estimated by the Kaplan-Meier survival method. The significance of different variables with respect to survival was analyzed by using the Cox regression assay. Cell experiments were applied to investigate the functional role of miR-601 in GC.

Results

We found that miR-601 was significantly up-regulated in GC tissues and cells compared with the controls (all P < 0.01). The levels of miR-601 expression were significantly associated with TNM stage, lymph node metastasis, lymphatic invasion, and distant metastasis (all P < 0.05). Kaplan-Meier survival analysis showed that patients in the high miR-601 expression group had poor overall survival (log-rank P = 0.001). Moreover, we confirmed that miR-601, TNM stage, and distant metastasis were independent prognostic factors for GC patients. Overexpression of miR-601 in AGS and SGC-7901 cells by miR-601 mimic transfection significantly promoted the cell proliferation, migration, and invasion (P < 0.05).

Conclusions

The expression level of miR-601 is dramatically up-regulated in GC. The overexpression of miR-601 promotes the tumor progression of GC, and may be a novel prognostic factor for poor survival in GC patients.

Automatic discovery of 100-miRNA signature for cancer classification using ensemble feature selection

Background

MicroRNAs (miRNAs) are noncoding RNA molecules heavily involved in human tumors, in which few of them circulating the human body. Finding a tumor-associated signature of miRNA, that is, the minimum miRNA entities to be measured for discriminating both different types of cancer and normal tissues, is of utmost importance. Feature selection techniques applied in machine learning can help however they often provide naive or biased results.

Results

An ensemble feature selection strategy for miRNA signatures is proposed. miRNAs are chosen based on consensus on feature relevance from high-accuracy classifiers of different typologies. This methodology aims to identify signatures that are considerably more robust and reliable when used in clinically relevant prediction tasks. Using the proposed method, a 100-miRNA signature is identified in a dataset of 8023 samples, extracted from TCGA. When running eight-state-of-the-art classifiers along with the 100-miRNA signature against the original 1046 features, it could be detected that global accuracy differs only by 1.4%. Importantly, this 100-miRNA signature is sufficient to distinguish between tumor and normal tissues. The approach is then compared against other feature selection methods, such as UFS, RFE, EN, LASSO, Genetic Algorithms, and EFS-CLA. The proposed approach provides better accuracy when tested on a 10-fold cross-validation with different classifiers and it is applied to several GEO datasets across different platforms with some classifiers showing more than 90% classification accuracy, which proves its cross-platform applicability.

Conclusions

The 100-miRNA signature is sufficiently stable to provide almost the same classification accuracy as the complete TCGA dataset, and it is further validated on several GEO datasets, across different types of cancer and platforms. Furthermore, a bibliographic analysis confirms that 77 out of the 100 miRNAs in the signature appear in lists of circulating miRNAs used in cancer studies, in stem-loop or mature-sequence form. The remaining 23 miRNAs offer potentially promising avenues for future research.

Electronic supplementary material

The online version of this article (10.1186/s12859-019-3050-8) contains supplementary material, which is available to authorized users.

Inhibition of microRNA-103a inhibits the activation of astrocytes in hippocampus tissues and improves the pathological injury of neurons of epilepsy rats by regulating BDNF

Background

The aim of this study is to explore the effect of microRNA-103a (miR-103a) on astrocytes activation and hippocampal neuron injury in epilepsy rats by targeting brain-derived neurotrophic factor (BDNF).

Methods

The epilepsy rat model was induced by intraperitoneal injection of lithium chloride-pilocarpine. Successful modeled rats were intralateroventricularly microinjected with miR-103a inhibitors, inhibitors negative control (NC), siRNA-NC and BDNF-siRNA, respectively. The RT-qPCR and western blot analysis were used to detect the expression of miR-103a, BDNF and glial fibrillary acidic protein (GFAP) in hippocampus tissues of rats. TUNEL staining was used to detect the apoptosis of hippocampal neurons. The RT-PCR and ELISA was used to detect the levels of TNF-α and IL-6 in hippocampal tissues and in serum, respectively.

Results

Increased expression of miR-103a, GFAP, and number of apoptotic neurons, decreased expression of BDNF and number of surviving neurons were found in hippocampus tissues of epilepsy rats. After miR-103a inhibitors interfered with epilepsy rats, there showed decreased expression of miR-103a and GFAP, increased expression of BDNF and decreased number of apoptotic neuron as well as increased number of surviving neurons. Compared with miR-103a inhibitors alone, epilepsy rats treated with BDNF-siRNA combined with miR-103a inhibitors significantly increased expression of GFAP in hippocampal tissues of epilepsy rats, increased number of apoptotic neurons and significantly decreased the number of surviving neurons.

Conclusion

Our study provides evidence that the inhibition of miR-103a can inhibit the activation of astrocytes in hippocampus tissues and improve the pathological injury of neurons of epilepsy rats by regulating BDNF gene.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0821-2) contains supplementary material, which is available to authorized users.

A meta-analysis of dysregulated miRNAs in coronary heart disease

AIMS

To combine the results of dysregulated miRNAs in individual coronary heart disease (CHD) studies and to identify potential miRNA biomarkers.

MAIN METHODS

MiRNA profiling studies of CHD were extracted from Pubmed, Embase, Web of Science and China National Knowledge Internet (CNKI) databases if they met the inclusion criteria. The meta-analysis was conducted using a random effects model to identify the effect of each multiple-reported miRNA. We also performed subgroup analysis according to miRNA detecting methods, tissues and subtypes of CHD. Sensitivity analysis was performed on the sample size. Bioinformatic analysis was performed to identify the potential biomatic functions. All results were represented as log10 odds ratios (logORs).

KEY FINDINGS

A total of 239 miRNAs were reported to be dysregulated in all 25 studies analyzed herein, and meta-analysis identified 48 statistically significant miRNAs. Bioinformatic analysis showed they were closely related with CHD. The most reported up-regulated miRNA was miR-122-5p (logOR: 2.7924, P < 0.001). A total of 7, 6, 4 and 9 miRNAs were detected to be differentially expressed in myocardial infarction (MI), unstable angia (UA), stable angina (SA) and pre-CHD subjects, respectively. 32 miRNAs were dysregulated in blood sample. The dysregulation of miR-133a-3p in whole blood and plasma/serum was contrary. In sensitivity analysis, 37 out of 48 (77.08%) miRNAs were consistently dysregulated.

SIGNIFICANCE

A total of 48 dysregulated miRNAs were confirmed in this meta-analysis. MiR-122-5p and miR-133a-3p may be valuable biomarkers for CHD.

Behavior of blood plasma glycan features in bladder cancer

Despite systemic therapy and cystectomy, bladder cancer is characterized by a high recurrence rate. Serum glycomics represents a promising source of prognostic markers for monitoring patients. Our approach, which we refer to as "glycan node analysis", constitutes the first example of molecularly "bottom-up" glycomics. It is based on a global glycan methylation analysis procedure that is applied to whole blood plasma/serum. The approach detects and quantifies partially methylated alditol acetates arising from unique glycan features such as α2-6 sialylation, β1-4 branching, and core fucosylation that have been pooled together from across all intact glycans within a sample into a single GC-MS chromatographic peak. We applied this method to 122 plasma samples from former and current bladder cancer patients (n = 72 former cancer patients with currently no evidence of disease (NED); n = 38 non-muscle invasive bladder cancer (NMIBC) patients; and n = 12 muscle invasive bladder cancer (MIBC) patients) along with plasma from 30 certifiably healthy living kidney donors. Markers for α2-6 sialylation, β1-4 branching, β1-6 branching, and outer-arm fucosylation were able to separate current and former (NED) cases from certifiably healthy controls (ROC curve c-statistics ~ 0.80); but NED, NMIBC, and MIBC were not distinguished from one another. Based on the unexpectedly high levels of these glycan nodes in the NED patients, we hypothesized that recurrence of this disease could be predicted by some of the elevated glycan features. Indeed, α2-6 sialylation and β1-6 branching were able to predict recurrence from the NED state using a Cox proportional hazards regression model adjusted for age, gender, and time from cancer. The levels of these two glycan features were correlated to C-reactive protein concentration, an inflammation marker and known prognostic indicator for bladder cancer, further strengthening the link between inflammation and abnormal plasma protein glycosylation.

Enhanced plasma miR-26a-5p promotes the progression of bladder cancer via targeting PTEN

The current study aimed to evaluate the expression and specific role of miR-26a-5p in the progression of bladder cancer (BC). Reverse transcription-quantitative polymerase chain reaction analysis was performed to evaluate the level of miR-26a-5p in BC cancer and healthy controls. The present data showed that plasma miR-26a-5p was significantly increased in BC patients. Furthermore, BC tissues exhibited greater levels of miR-26a-5p compared with adjacent non-neoplastic tissues-26a-5p. Compared with BC patients at Ta-T1 stage, the level of miR-26a-5p was significantly elevated in BC patients ≥T2. BC patients at G3 stage demonstrated a higher plasma miR-26a-5p level compared with those at G1/2 stage. Receiver operating characteristic (ROC) analysis indicated that miR-26a-5p could differentiate BC patients from controls. Additionally, Kaplan-Meier analysis demonstrated that plasma miR-26a-5p negatively correlated with survival of BC patients. Dual luciferase reporter assay indicated that miR-26a-5p significantly suppressed the relative luciferase activity of pmirGLO-PTEN-3′UTR compared with the control. In conclusion, the current study indicated novel data that the levels of plasma miR-26a-5p was significantly increased in BC patients. Furthermore, the present study suggested that determination of plasma miR-26a-5p level could help to distinguish BC patients from healthy controls via targeting PTEN.

Circulating miRNAs in blood and urine as diagnostic and prognostic biomarkers for bladder cancer: an update in 2017

This study presents a critical appraisal of previously published study data of miRNAs in blood, urine and exosomes as biomarkers of bladder cancer (BC). The evaluation included 39 articles published from the beginning of 2010 until September 2017 and searched in PubMed. The heterogeneity of studies, due to their clinicopathological variability, including insufficient consideration of diagnostic and prognostic biomarker guidelines and missing internal and external validation of data, do not currently allow the recommending of a useful miRNA marker as diagnostic or prognostic tool in BC. Future multi-institutional studies are necessary to overcome the deficiencies in these studies in order to prove the usefulness of circulating miRNAs as robust biomarkers for BC.

miR-224/miR-141 ratio as a novel diagnostic biomarker in renal cell carcinoma

Biomarkers to guide the clinical treatment of patients with renal cell carcinoma (RCC) are not yet routinely available. MicroRNAs (miRNAs) have been demonstrated to serve as biomarkers for a number of types of cancer. Based on a previous study by this group, we hypothesize that several highly differentially expressed miRNAs may serve as tissue and plasma biomarkers in patients with RCC. The expression levels of miR-210, miR-224 and miR-141 were analyzed in tissue samples from the same cohort of 78 patients with RCC, in paired pre- and post-operative plasma samples from 66 patients with clear cell RCC (ccRCC) and in 67 healthy controls by reverse transcription-quantitative polymerase chain reaction. Receiver operating characteristic (ROC) was used to evaluate the diagnostic accuracy associated with the expression of miR-210, miR-224 and miR-141. ROC curves revealed that the diagnostic accuracy (area under the curve) of tissue miR-210, miR-224, the ratio of miR-210/miR-141 (miR^210/141), miR-224/miR-141 (miR^224/141) and miR-210× miR-224/miR-141 (miR^210×224/141) in ccRCC was 0.8329, 0.8511, 0.9412, 0.9898 and 0.9771, respectively. Notably, miR^224/141 demonstrated the highest accuracy among these miRNAs for discriminating ccRCC tissues from normal tissues, with a sensitivity of 97.06% and a specificity of 98.53%. The expression levels of plasma miR-210 and miR-224 were significantly increased in patients compared with healthy control patients, and were reduced postoperatively (P<0.05). The diagnostic accuracy of plasma miR-210 and miR-224 were 0.6775 (89.55% sensitivity and 48.48% specificity) and 0.6056 (88.06% sensitivity and 40.91% specificity), respectively. The present study indicated that the tissue miR-224/miR-141 ratio is a potentially powerful tool for detecting ccRCC. However, plasma miR-210 and miR-224 may not be associated with diagnosis of ccRCC.

eNOS expression and NO release during hypoxia is inhibited by miR-200b in human endothelial cells

The nitric oxide (NO) secreted by vascular endothelium is required for the maintenance of cardiovascular homeostasis. Diminished release of NO generated by endothelial NO synthase contributes to endothelial dysfunction. Hypoxia and ischemia reduce endothelial eNOS expression via posttranscriptional mechanisms that result in NOS3 transcript destabilization. Here, we examine whether microRNAs contribute to this mechanism. We followed the kinetics of hypoxia-induced changes in NOS3 mRNA and eNOS protein levels in primary human umbilical vein endothelial cells (HUVECs). Utilizing in silico predictive protocols to identify potential miRNAs that regulate eNOS expression, we identified miR-200b as a candidate. We established the functional miR-200b target sequence within the NOS3 3′UTR, and demonstrated that manipulation of the miRNA levels during hypoxia using miR-200b mimics and antagomirs regulates eNOS levels, and established that miR-200b physiologically limits eNOS expression during hypoxia. Furthermore, we demonstrated that the specific ablation of the hypoxic induction of miR-200b in HUVECs restored eNOS-driven hypoxic NO release to the normoxic levels. To determine whether miR-200b might be the only miRNA that had this effect, we utilized Next Generation Sequencing (NGS) to follow hypoxia-induced changes in the miRNA levels in HUVECS and found 83 novel hypoxamiRs, with two candidate miRNAs besides miR-200b that could potentially influence eNOS levels. Taken together, the data establish miR-200b-eNOS regulation as a first hypoxamiR-based mechanism that limits NO bioavailability during hypoxia in endothelial cells, and show that hypoxamiRs could become useful therapeutic targets for cardiovascular diseases and other hypoxic-related diseases including various types of cancer.

Restoration of microRNA-130b expression suppresses osteosarcoma cell malignant behavior in vitro

The alteration of microRNA (miR)-130b expression has been associated with promoting or suppressing numerous types of human cancer. A previous study evaluated the expression level of miR-130b in osteosarcoma tissues, and subsequently investigated the effects of miR-130b on the regulation of osteosarcoma cells malignant behavior in vitro. The study revealed that miR-130b expression levels were significantly reduced in osteosarcoma tissues and cell lines, compared with in adjacent tissues or normal cell lines. The expression of miR-130b inhibited the proliferation of osteosarcoma U-2OS and Saos-2 cells and impaired their ability to migrate, invade and form colonies. Furthermore, analysis using TargetScan and a dual-luciferase reporter assay demonstrated that miR-130b directly interacted with the 3′-untranslated region of transforming growth factor α (TGFA) and suppressed TGFA expression. TGFA and miR-130b were also inversely expressed in osteosarcoma tissues. In addition, expression of TGFA was able to alter miR-130-regulated osteosarcoma cell proliferation, migration and invasion. Thus, the present study demonstrated that miR-130b was downregulated in osteosarcoma tissues and cell lines, whereas the expression of miR-130b suppressed osteosarcoma cell malignant behavior. At the gene level, miR-130 directly targets and inhibits TGFA expression, in addition to phosphorylated protein kinase B and epidermal growth factor receptor expression levels. Further study is required to evaluate miR-130b antitumor activity in osteosarcoma.

The role of circulating tumour cells and nucleic acids in blood for the detection of bladder cancer: A systematic review

BACKGROUND

Blood-based biomarkers are a neglected resource in bladder cancer, where the mainstay of focus has been on urinary biomarkers. However, blood-based biomarkers are gaining popularity in other solid cancers, particularly circulating tumour cells (CTCs) and circulating nucleic acids. In this systematic review, we identify and discuss the diagnostic value of CTC, cell-free DNA and RNA based biomarkers in bladder cancer.

METHODS

A MEDLINE/Pubmed systematic search was performed using the following keywords: (bladder cancer) AND (blood OR plasma OR serum) AND biomarker AND (DNA OR RNA OR cfDNA OR cell-free DNA OR RNA OR CTC). All studies including blood-based biomarkers based on DNA, RNA and CTCs were reviewed. Of the included studies, studies reporting sensitivity, specificity and/or AUC/ROC values were further described.

RESULTS

Systematic searched yielded 47 studies that were eligible, of which 21, 19 and 3 studies reported DNA, RNA and CTC biomarkers respectively. 15 of these studies included sensitivity, specificity and/or AUC/ROC values. Biomarkers sensitivity and specificity ranged widely at 2.4-97.6% and 43.3-100% respectively. Median number of patients recruited in the studies was 56 (IQR 41-90). Only 3 studies included an independent validation cohort. The highest sensitivity and specificity pairing achieved in the validation cohort was 80.0% and 89.1% respectively.

CONCLUSIONS

This systematic review provides a comprehensive overview of the blood-based CTC and nucleic acid biomarkers that have been investigated. An overlap in interest of targets between studies suggests that these could be promising biomarkers, but few biomarkers achieve high sensitivity and specificity, and fewer still have been validated independently.

microRNA profiles in urine by next-generation sequencing can stratify bladder cancer subtypes

Bladder cancer (BC) is the most frequent malignancy of the urinary tract with a high incidence in men and smokers. Currently, there are no non-invasive markers useful for BC diagnosis and subtypes classification that could overcome invasive procedures such as cystoscopy. Dysregulated miRNA profiles have been associated with numerous cancers, including BC. Cell-free miRNAs are abundantly present in a variety of biofluids including urine and make them promising candidates in cancer biomarker discovery.

In the present study, the identification of miRNA fingerprints associated with different BC status was performed by next-generation sequencing on urine samples from 66 BC and 48 controls. Three signatures based on dysregulated miRNAs have been identified by regression models, assessing the power to discriminate different BC subtypes. Altered miRNAs according to invasiveness and grade were validated by qPCR on 112 cases and 65 controls (among which 46 cases and 16 controls were an independent group of subjects while the rest were replica samples).

The area under the curve (AUC) computed including three miRNAs (miR-30a-5p, let-7c-5p and miR-486-5p) altered in all BC subtypes showed a significantly increased accuracy in the discrimination of cases and controls (AUC model = 0.70; p-value = 0.01).

In conclusions, the non-invasive detection in urine of a selected number of miRNAs altered in different BC subtypes could lead to an accurate early diagnosis of cancer and stratification of patients.

Serum microRNAs as predictors of risk for non-muscle invasive bladder cancer

MicroRNAs (miRNAs) are implicated in the development of nearly all cancers and may function as promising biomarkers for early detection, diagnosis and prognosis. We sought to investigate the role of serum miRNAs as potential diagnostic biomarkers or biomarkers of risk for early-stage bladder cancer. First, we profiled global serum miRNAs in a pilot set of 10 non-muscle invasive bladder cancer (NMIBC) cases and 10 healthy controls matched on age, gender and smoking status. Eighty nine stably detectable miRNAs were selected for further testing and quantification by high-throughput Taqman analysis using the Fluidigm BioMark HD System to assess their association with NMIBC risk in both discovery and validation sets totaling 280 cases and 278 controls. We found miR-409-3p and six miRNAs expression ratios were significantly associated with risk of bladder cancer in both discovery and validation sets. Interestingly, we identified expression of miR-409-3p and miR-342-3p inversely correlated with age and age of onset of NMIBC. A risk score was generated based on the combination of three miRNA ratios (miR-29a-3p/miR-222-3p, miR-150-5p/miR-331-3p, miR-409-3p/miR-423-5p). In dichotomized analysis, we found individuals with high risk score showed increased risk of bladder cancer in the discovery, validation, and combined sets. Pathway enrichment analyses suggested altered miRNAs and cognate target genes are linked to the retinoid acid receptor (RAR) signaling pathway. Overall, these results suggested specific serum miRNA signatures may serve as noninvasive predictors of NMIBC risk. Biological insights underlying bladder cancer development based on the pathway enrichment analysis may reveal novel therapeutic targets for personalized medicine.

The miR-644a/CTBP1/p53 axis suppresses drug resistance by simultaneous inhibition of cell survival and epithelial-mesenchymal transition in breast cancer

Tumor cells develop drug resistance which leads to recurrence and distant metastasis. MicroRNAs are key regulators of tumor pathogenesis; however, little is known whether they can sensitize cells and block metastasis simultaneously. Here, we report miR-644a as a novel inhibitor of both cell survival and EMT whereby acting as pleiotropic therapy-sensitizer in breast cancer. We showed that both miR-644a expression and its gene signature are associated with tumor progression and distant metastasis-free survival. Mechanistically, miR-644a directly targets the transcriptional co-repressor C-Terminal Binding Protein 1 (CTBP1) whose knock-outs by the CRISPR-Cas9 system inhibit tumor growth, metastasis, and drug resistance, mimicking the phenotypes induced by miR-644a. Furthermore, downregulation of CTBP1 by miR-644a upregulates wild type- or mutant-p53 which acts as a 'molecular switch' between G1-arrest and apoptosis by inducing cyclin-dependent kinase inhibitor 1 (p21, CDKN1A, CIP1) or pro-apoptotic phorbol-12-myristate-13-acetate-induced protein 1 (Noxa, PMAIP1), respectively. Interestingly, an increase in mutant-p53 by either overexpression of miR-644a or downregulation of CTBP1 was enough to shift this balance in favor of apoptosis through upregulation of Noxa. Notably, p53-mutant patients, but not p53-wild type ones, with high CTBP1 have a shorter survival suggesting that CTBP1 could be a potential prognostic factor for breast cancer patients with p53 mutations. Overall, re-activation of the miR-644a/CTBP1/p53 axis may represent a new strategy for overcoming both therapy resistance and metastasis.

Plasma miR-324-3p and miR-1285 as diagnostic and prognostic biomarkers for early stage lung squamous cell carcinoma

BACKGROUND

Specific biomarkers for early detection and outcome prediction of lung squamous cell carcinoma (LSCC) are still lacking. This study assessed the differentially expressed miRNAs as potential biomarkers for early stage LSCC.

RESULTS

Base on the results of multi-phase study, we found that miR-324-3p was significantly up-regulated, whereas mir-1285 was significantly down-regulated in plasma of stage I LSCC patients compared to healthy controls. ROC analysis showed that AUC of miR-324-3p and miR-1285 were 0.79 and 0.85, respectively. The combination of these two miRNAs could further improve the diagnostic accuracy (AUC = 0.89). The multivariate analysis revealed that plasma miR-324-3p level was an independent prognostic predictor for early stage LSCC.

METHODS

395 patients and 195 healthy controls were enrolled in this study. We screened the differentially expressed plasma miRNAs using TaqMan Low Density Arrays (TLDA) followed by three-phase qRT-PCR validation. We also evaluated the association of candidate miRNAs with overall survival of early stage LSCC patients. Finally, the target genes of the candidate miRNAs were analyzed using public available databases and bioinformatics methods.

CONCLUSIONS

The current study suggests that plasma miR-324-3p and miR-1285 levels could serve as LSCC early detection markers while miR-324-3p may serve as a prognostic marker for LSCC patients.

Clinical value and potential pathways of miR-183-5p in bladder cancer: A study based on miRNA-seq data and bioinformatics analysis

The clinicopathological value and exploration of the potential molecular mechanism of microRNA-183-5p (miR-183-5p) have been investigated in various cancers; however, to the best of the author's knowledge, no similar research has been reported for bladder cancer. In the present study, it was revealed that the expression level of miR-183-5p was notably increased in bladder cancer tissues compared with adjacent non-cancerous tissues (P=0.001) and was markedly increased in the tissue samples of papillary, pathological T stage (T0-T2) and pathological stage (I-II) compared with tissue samples of their counterparts (P=0.05), according to data from The Cancer Genome Atlas. Receiver operating characteristic analysis revealed the robust diagnostic value of miR-183-5p for distinguishing bladder cancer from non-cancerous bladder tissues (area under curve=0.948; 95% confidence interval: 0.919-0.977). Amplification and deep deletion of miR-183-5p were indicated by cBioPortal, accounting for 1% (4/412) of bladder cancer cases. Data from YM500v3 demonstrated that compared with other cancers, bladder cancer exhibited high expression levels of miR-183-5p, and miR-183-5p expression in primary solid tumors was much higher compared with solid normal tissues. A meta-analysis indicated that miR-183-5p was more highly expressed in bladder cancer samples compared with normal counterparts. A total of 88 potential target genes of miR-183-5p were identified, 13 of which were discerned as hub genes by protein-protein interaction. The epithelial-to-mesenchymal transition pathway was the most significantly enriched pathway by FunRich (P=0.0001). In summary, miR-183-5p may participate in the tumorigenesis and development of bladder cancer via certain signaling pathways, particularly the epithelial-to-mesenchymal transition pathway. However, the exact molecular mechanism of miR-183-5p in bladder cancer must be validated by in vitro and in vivo experiments.

miR-130b, an onco-miRNA in bladder cancer, is directly regulated by NF-κB and sustains NF-κB activation by decreasing Cylindromatosis expression

Persistent activation of NF-κB signaling is closely related to chronic inflammation and tumorigenesis. Commonly, NF-κB signaling is tightly controlled by multiple feedback loops and regulators, such as the deubiquitinases (DUBs). However, in cancer cells, NF-κB may override these feedbacks through special pathways and lead to the sustained activation. In the present study, we demonstrate that in transitional cell carcinoma (TCC) of bladder, miR-130b plays an oncogenesis role, it enhanced proliferation, invasion and migration of TCC cell, and was highly correlated with tumor progression. On the other hand, NF-κB directly regulated the transcription of miR-130b by binding with its promoter region. Importantly, we verify that, through deceasing the expression of Cylindromatosis (CYLD), a K63-specific DUB and endogenous blocker of NF-κB signaling, miR-130b can in return sustain the persistent activation of NF-κB, which may promote the malignant progression of TCC. Thus, the present study uncovers a potential signaling transduction in which NF-κB is continuously activated, and may provide a novel therapeutic approach for the clinical management of TCC.

Anticancer effect of miR-96 inhibitor in bladder cancer cell lines

The present study aimed to investigate the role of microRNA-96 (miR-96) in the proliferation, invasion and apoptosis of bladder cancer cell lines, and the associated mechanisms. The expression of miR-96 and human ether-à-go-go-related (HERG1) potassium channel in the normal uroepithelium SV-HUC-1 cell line, and bladder cancer T24 and 5637 cell lines were examined using reverse transcription-polymerase chain reaction or/and western blotting. Transfection with miR-96 inhibitor or scrambled control (SC) was used to study the biological activities of miR-96 in bladder cancer cell lines. MTT, flow cytometric and Transwell assays were applied to detect cell viability, apoptosis and invasion, respectively. A dual-luciferase reporter assay was applied to determine the association between miR-96 and HERG1 expression. As demonstrated, miR-96 was highly expressed in the two bladder cancer cell lines, particularly in T24 cells. Following transfection with miR-96 inhibitor, miR-96 expression was significantly reduced in the T24 cell line, compared with SC. The miR-96 inhibitor suppressed cell proliferation and invasion, promoted apoptosis and arrested the cell cycle at the G₁ phase. Consistently, HERG1 was also highly expressed in the two bladder cancer cell lines at the mRNA and protein level, but not in the normal uroepithelium cell line. The miR-96 inhibitor also significantly decreased HERG1 expression compared with SC. The results of the dual-luciferase reporter assay indicated that miR-96 directly targeted wild-type HERG1. In conclusion, miR-96 inhibitor exhibited anticancer effects on bladder cancer cells by inhibiting proliferation and invasion of cells, and promoting their apoptosis. HERG1 was an important target of miR-96. These results provided experimental evidence supporting miR-96 as a therapeutic target for patients with bladder cancer.

Suppression of microRNA-130b inhibits glioma cell proliferation and invasion, and induces apoptosis by PTEN/AKT signaling

Glioblastoma is the most common malignant brain tumor in adults and is characterized by extensive proliferation and the diffused invasion of tumor cells. Due to the intricate signaling pathways involved in glioma progression, more effective targeted therapies and prognostic biomarkers in clinical practice are required. The suppression of proto-oncogene function or recovery of tumor suppressor gene function remains one of the primary approaches in gene therapy. The close association between the abnormal expression or mutation of microRNA (miRNA) and the tumorigenesis, progression and staging in glioma have been demonstrated previously. However, the expression pattern and specific role of microRNA‑130b (miR‑130b) in the tumor occurrence and progression of glioma are unclear. In the present study, quantitative polymerase chain reaction was performed to determine the expression level of miR-130b in 30 brain glioma patients and 3 glioma cell lines. An miR‑130b inhibitor was transfected into U87 cells to downregulate the expression of miR-130b, and assessments of cell proliferation, cell cycle, apoptosis, cell invasion and migration in vitro and nude mouse tumorigenicity in vivo were conducted. Western blotting and luciferase reporter gene technology were used to verify the downstream target gene of miR-130b, namely phosphatase and tensin homolog (PTEN). The results demonstrated that miR-130b expression was increased in glioma tissues and cell lines in comparison with non-glioma tissues or cells. The downregulated expression of miR-130b inhibited the proliferation and invasion of glioma cells, induced apoptosis of the cells in vitro and inhibited their tumorigenicity in vivo. Western blotting and luciferase reporter assays demonstrated that the PTEN gene is a direct target of miR‑130b. Western blotting revealed that the miR-130b inhibitor upregulated the expression of PTEN, inhibited AKT pathway activation, upregulated the tumor suppressor gene p27, and suppressed cyclin D1, matrix metalloproteinase 2 and 9 expression. These results suggest that the miR-130b inhibitor suppressed glioma cell proliferation and invasion via the PTEN/AKT pathway. Therefore, miR‑130b is suggested to be an effective therapeutic target for glioma.

MicroRNAs in biofluids are novel tools for bladder cancer screening

MicroRNAs (miRNAs) are short non-coding RNAs that play important roles in basic cellular processes, including differentiation, proliferation, apoptosis and autophagy. They are also involved in various stages of tumorigenesis and play key roles in bladder cancer initiation and progression. Notably, the altered expression of miRNAs in the tumors is reflected in body fluids, including blood and urine, which opens avenues for non-invasive diagnosis and prognosis. Many studies have demonstrated that epigenetic changes extensively alter tumoral microRNA expression. The high reproducibility, specificity and sensitivity of miRNA levels in body fluids suggest their potential use as biomarkers for cancer screening and diagnosis. For example, recent technological advances have made it possible to detect miRNAs in urine for bladder cancer screening. In this review, we focus mainly on the current knowledge and future challenges for incorporating miRNAs in body fluids, like urine and blood, for making clinical diagnoses and assessing prognoses in bladder cancer.

Exosomes of invasive urothelial carcinoma cells are characterized by a specific miRNA expression signature

Muscle-invasive bladder cancer (MIBC) represents a highly aggressive tumor type compared to non-muscle-invasive tumors. MIBC is characterized by specific molecular alterations, which may also modulate extracellular tumorigenic effects. Tumor-associated exosomes, especially exosomal miRNAs, are important regulators in the interaction between tumor cells and tumor microenvironment by affecting tumor-promoting processes in target cells. It is important to analyze whether their exosomal patterns also reflect the specific molecular characteristics of MIBC. The aim of this study was to compare the miRNA expression in secreted exosomes from urinary bladder cancer cells (UBC) with different degrees of invasiveness. By electron microscopy, nanotracking analysis and western blot we proofed a high quality of isolated exosomes. Microarray analysis identified an invasion-associated signature of 15 miRNAs, which is significantly altered in exosomes of invasive UBC compared to non-invasive counterparts. Therefrom, 9 miRNAs are consistent differently expressed in both, invasive cells and their secreted exosomes. The remaining 6 exosome-specific miRNAs are only deregulated in exosomes but not in their parental cells. MiRNA alterations were verified by qPCR in cell culture and urinary exosomes. In conclusion, we showed that exosomes from invasive UBC cells are characterized by a specific miRNA signature. Further analyses have to clarify the functional relevance of exosomal miRNAs secreted by invasive bladder cancer cells for modification of the tumor microenvironment and their putative role as molecular markers in liquid biopsies.

MiR-372-3p promotes cell growth and metastasis by targeting FGF9 in lung squamous cell carcinoma

The aim of this study was to study the role of miR‐372‐3p in lung squamous cell carcinoma (LSCC) cell proliferation and invasion by suppressing FGF9. RT‐PCR was used to determine miR‐372‐3p and FGF9 mRNA expression in tissues and cells. Western blot was used to determine FGF9 expression in tissues and NCI‐H520 cell line. Dual luciferase reporter gene assay was conducted to confirm that FGF9 can be directly targeted by miR‐372‐3p. MTT, colony formation assays were conducted to investigate the effects of ectopic miR‐372‐3p and FGF9 expression on NCI‐H520 cell growth. Flow cytometry was used to analyze the influence of miR‐372‐3p and FGF9 expression on cell cycle distribution and apoptosis. Transwell assay was also conducted to see the effects of miR‐372‐3p and FGF9 expression on NCI‐H520 cell invasiveness. MiR‐372‐3p was found significantly overexpressed in both LSCC tissues and cell lines, whereas FGF9 mRNA was found underexpressed in LSCC tissues. MiR‐372‐3p directly bound to wild‐type FGF9 mRNA 3′UTR, therefore led to the reduction in FGF9 expression. The upregulation of FGF9 or the downregulation of miR‐372‐3p substantially retarded LSCC cell growth, mitosis, and invasion. MiR‐372‐3p enhanced LSCC cell proliferation and invasion through inhibiting FGF9.

A panel of microRNA signature in serum for colorectal cancer diagnosis

Dysregulated expression of specific microRNAs (miRNAs) in serum has been recognised as promising diagnostic biomarkers for colorectal cancer (CRC). In the initial screening phase, a total of 32 differentially expressed miRNAs were selected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) based Exiqon panel with 3 CRC pool samples and 1 normal control (NC) pool. Using qRT-PCR, selected serum miRNAs were further confirmed in training (30 CRC VS. 30 NCs) and testing stages (136 CRC VS. 90 NCs). We identified that serum levels of miR-19a-3p, miR-21-5p and miR-425-5p were significantly higher in patients with CRC than in NCs. The areas under the receiver operating characteristic (ROC) curve of the three-miRNA panel were 0.86, 0.74 and 0.87 for the training, testing and the external validation stages (30 CRC VS. 18 NCs), respectively. Significantly, elevated expression of the three miRNAs was also observed in CRC tissues (n = 24). Furthermore, the expression levels of the three miRNAs were significantly elevated in exosomes from CRC serum samples (n = 10). In conclusion, we identified a serum three-miRNA panel for the diagnosis of CRC.

Serum-circulating miRNAs predict neuroblastoma progression in mouse model of high-risk metastatic disease

Background

Circulating miRNAs have momentous clinical relevance as prognostic biomarkers and in the progression of solid tumors. Recognizing novel candidates of neuroblastoma-specific circulating miRNAs would allow us to identify potential prognostic biomarkers that could predict the switch from favorable to high-risk metastatic neuroblastoma (HR-NB).

Results

Utilizing mouse models of favorable and HR-NB and whole miRnome profiling, we identified high serum levels of 34 and low levels of 46 miRNAs in animals with HR-NB. Preferential sequence homology exclusion of mouse miRNAs identified 25 (11 increased; 14 decreased) human-specific prognostic marker candidates, of which, 21 were unique to HR-NB. miRNA QPCR validated miRnome profile. Target analysis defined the candidate miRNAs' signal transduction flow-through and demonstrated their converged roles in tumor progression. miRNA silencing studies verified the function of select miRNAs on the translation of at least 14 target proteins. Expressions of critical targets that correlate tumor progression in tissue of multifarious organs identify the orchestration of HR-NB. Significant (>10 fold) increase in serum levels of miR-381, miR-548h, and miR-580 identify them as potential prognostic markers for neuroblastoma progression.

Conclusion

For the first time, we identified serum-circulating miRNAs that predict the switch from favorable to HR-NB and, further imply that these miRNAs could play a functional role in tumor progression.

Identification of aberrant tRNA-halves expression patterns in clear cell renal cell carcinoma

Small non-coding RNAs (sncRNA; <200 nt) regulate various cellular processes and modify gene expression. Under nutritional, biological or physiochemical stress some mature sncRNAs (e.g. tRNAs) are cleaved into halves (30–50 nt) and smaller fragments (18–22 nt); the significance and functional role of these tRNA fragments is unknown, but their existence has been linked to carcinogenesis. We used small RNA sequencing to determine the expression of sncRNAs. Subsequently the findings were validated for miR-122-5p, miR-142-3p and 5'tRNA4-Val-AAC using qPCR. We identified differential expression of 132 miRNAs (upregulated: 61, downregulated: 71) and 32 tRNAs (upregulated: 13, downregulated: 19). Read length analysis showed that miRNAs mapped in the 20–24 nt fraction, whereas tRNA reads mapped in the 30–36 nt fraction instead the expected size of 73–95 nt thereby indicating cleavage of tRNAs. Overexpression of miR-122-5p and miR-142-3p as well as downregulation of 5'tRNA4-Val-AAC was validated in an independent cohort of 118 ccRCC and 74 normal renal tissues. Furthermore, staging and grading was inversely correlated with the 5'tRNA4-Val-AAC expression. Serum levels of miR-122-5p, miR-142-3p and 5'tRNA4-Val-AAC did not differ in ccRCC and control subjects. In conclusion, 5′ cleavage of tRNAs occurs in ccRCC, but the exact functional implication of tRNA-halve deregulation remains to be clarified.

Extracellular vesicles as a source for non-invasive biomarkers in bladder cancer progression

Bladder cancer is the second most frequent malignancy of the urinary tract after prostate cancer. Current diagnostic techniques, such as cystoscopy and biopsies are highly invasive and accompanied of undesirable side effects. Moreover, there are no suitable biomarkers for relapse or progression prognosis. We analysed whether the specific composition of microRNAs (miRNAs) and proteins of extracellular vesicles (EVs) that urothelial tumour cells of bladder mucosa release into the urine, could reflect their pathologic condition. For this purpose, urinary EVs were isolated and their protein and miRNA composition evaluated in healthy donors and low or high-grade bladder cancer patients. Using a microarray platform containing probes for 851 human miRNAs we found 26 deregulated miRNAs in high-grade bladder cancer urine EVs, from which 23 were downregulated and 3 upregulated. Real-time PCR analysis pointed to miR-375 as a biomarker for high-grade bladder cancer while miR-146a could identify low-grade patients. Finally, several protein markers were also deregulated in EVs from tumour patients. Our data suggest that the presence of ApoB in the 100,000 pellet is a clear marker for malignancy.

MicoRNA-425-5p is a potential prognostic biomarker for cervical cancer

Background

MicroRNAs have been implicated in many biological pathways involved in tumourigenesis and can serve as prognostic biomarkers in many cancer types. The present study aims at evaluating the prognostic significance of miR-425-5p in cervical cancer.

Methods

Real-time polymerase chain reaction was performed to assess the expression levels of miR-425-5p in 35 pairs of cervical cancer tissues and their matched normal tissues as well as serum samples from 40 cervical cancer patients, 13 benign cervical disease patients and 32 healthy controls. The association between miR-425-5p expression levels in tissue and serum, and clinicopathological factors was examined. The correlation between serum miR-425-5p expression levels and overall survival of cervical cancer patients was assessed by Kaplan–Meier analysis and Cox proportional hazards model.

Results

MiR-425-5p expression levels were significantly increased in cervical cancer tissues compared with matched non-cancerous tissues. Higher expression of miR-425-5p was positively associated with high tumour stage ( P = 0.0003) and positive lymph node metastasis ( P = 0.0107). Serum concentrations of miR-425-5p in cervical cancer patients were significantly higher compared with benign cervical disease and healthy controls. Moreover, the up-regulation of serum miR-425-5p occurred more frequently in cervical cancer patients with high TNM stage ( P = 0.0003) and positive lymph node metastasis ( P = 0.0037). Kaplan–Meier analysis showed that high serum miR-425-5p expression levels predicted poor survival ( P = 0.0571). Cox proportional hazards risk analysis demonstrated that miR-425-5p was an independent prognostic factor for cervical cancer.

Conclusion

Our study suggests that miR-425-5p is up-regulated in cervical cancer and serum miR-425-5p may serve as a potential prognostic biomarker for cervical cancer.

The emerging role of non-coding circulating RNA as a biomarker in renal cell carcinoma

INTRODUCTION

Bodily fluids like serum and plasma contain significant amounts of tumor-derived circulating cell-free RNA, which holds the potential to serve as diagnostic biomarker. Consequently, liquid biopsies comprising circulating cell-free RNA might help to facilitate personalized treatment strategies for patients with renal cell carcinoma (RCC). Areas covered: The present review provides a summary of the literature obtained by a PubMed search and covers the current knowledge on circulating non-coding cell-free RNA in patients with RCC. Expert commentary: Altered circulating microRNA and long non-coding RNAs signatures allow for the discrimination of patients with RCC and healthy individuals. On the other hand, little is known about non-coding RNA expression in benign tumors. Cell-free microRNA expression levels may help to identify patients at risk for disease recurrence. However, accurate determination of cell-free RNAs is methodologically challenging and currently no biomarker candidate has reached a sufficient level of clinical validation. Thus, short-term implementation of cell-free circulating microRNA into clinical routine seems unlikely.

Comprehensive investigation of aberrant microRNA profiling in bladder cancer tissues

There has been accumulative evidence that microRNAs (miRNAs) play essential roles in the tumorigenesis and progression of bladder cancer. However, individual studies and small sample size caused discrepant outcomes. Thus, the current study focused on a comprehensive profiling of all differentially expressed miRNAs in a total of 519 bladder cancer tissue samples, based on miRNA microarray data. Altogether, 11 prioritized miRNAs stated by 21 published microarray datasets, including five down-regulated (miR-133a-3p, miR-1-3p, miR-99a-5p, miR-490-5p, and miR-133b) and six up-regulated candidate miRNAs (miR-182-5p, miR-935, miR-518e-3p, miR-573, miR-100-3p, and miR-3171) were analyzed with vote-counting strategy and a Robust Rank Aggregation method. Subsequently, miRNA in silico target prediction and potential pathway enrichment analysis were performed to investigate the prospective molecular mechanism of miRNAs in the tumorigenesis of bladder cancer. We found that most of the relative pathways of the aberrantly expressed miRNAs found in the current study were closely correlated with different biological processes, cellular components, molecular functions, cancer pathogeneses, and some cell signalings, such as Wnt signaling, insulin/IGF, PI3 kinase, and FGF signaling pathways. Hence, a comprehensive overview on the miRNA expression pattern in bladder cancer tissues was gained by the current study. These miRNAs might be involved in the tumorigenesis and deterioration of bladder cancer.