Plasma miR-122 as a potential diagnostic and prognostic indicator in human glioma

MicroRNA as a potential diagnostic and prognostic biomarker in brain gliomas: a systematic review and meta-analysis

Introduction

Brain neoplasms and central nervous system (CNS) disorders, particularly gliomas, have shown a notable increase in incidence over the last three decades, posing significant diagnostic and therapeutic challenges. MicroRNAs (miRNAs) have emerged as promising biomarkers due to their regulatory role in gene expression, offering potential enhancements in glioma diagnosis and prognosis.

Methods

This systematic review and meta-analysis, adhering to PRISMA guidelines, included 25 studies for diagnostic accuracy and 99 for prognostic analysis, published until August 27th, 2023. Studies were identified through comprehensive searches of PubMed, Web of Science, and Scopus databases. Inclusion criteria encompassed peer-reviewed original research providing sensitivity, specificity, and area under the curve (AUC) for miRNAs in glioma diagnosis, as well as survival outcomes with hazard ratios (HRs) or mean survival.

Results and discussion

Meta-analysis demonstrated miRNAs' high diagnostic accuracy, with a pooled sensitivity of 0.821 (95% CI: 0.781-0.855) and specificity of 0.831 (95% CI: 0.792-0.865), yielding an AUC of 0.893. Subgroup analysis by specimen type revealed consistent accuracy across blood, cerebrospinal fluid (CSF), and tissue samples. Our results also showed miRNAs can be potential prognostic biomarkers. miRNAs showed significant associations with overall survival (OS) (pooled HR: 2.0221; 95% CI: 1.8497-2.2105), progression-free survival (PFS) (pooled HR: 2.4248; 95% CI: 1.8888-3.1128), and disease-free survival (DFS) (pooled HR: 1.8973; 95% CI: 1.1637-3.0933) in tissue specimens. These findings underscore miRNAs' potential as valuable biomarkers for improving glioma diagnosis and prognosis, offering insights for enhancing clinical decision-making and patient outcomes.

The Impact of miR-122 on Cancer

MiRNAs are confirmed to be a kind of short and eminently conserved noncoding RNAs, which regulate gene expression at the post-transcriptional level via binding to the 3'- untranslated region (3'-UTR) of targeting multiple target messenger RNAs. Recently, growing evidence stresses the point that they play a crucial role in a variety of pathological processes, including human cancers. Dysregulated miRNAs act as oncogenes or tumor suppressor genes in many cancer types. Among them, we noticed that miR-122 has been widely reported to significantly influence carcinogenicity in a variety of tumors by regulating target genes and signaling pathways. Here, we focused on the expression of miR-122 in regulatory mechanisms and tumor biological processes. We also discussed the effects of miR-122 dysregulation in various types of human malignancies and the potential to develop new molecular miR-122-targeted therapies. The present review suggests that miR-122 may be a potentially useful cancer diagnosis and treatment biomarker. More clinical diagnoses need to be further launched in the future. A promising direction to improve the outcomes for cancer patients will likely combine miR-122 with other traditional tumor biomarkers.

The role and mechanism of action of microRNA-122 in cancer: Focusing on the liver

microRNA-122 (miR-122) is a highly conserved microRNA that is predominantly expressed in the liver and plays a critical role in the regulation of liver metabolism. Recent studies have shown that miR-122 is involved in the pathogenesis of various types of cancer, particularly liver cancer. In this sense, The current findings highlighted the potential role of miR-122 in regulating many vital processes in cancer pathophysiology, including apoptosis, signaling pathway, cell metabolism, immune system response, migration, and invasion. These results imply that miR-122, which has been extensively studied for its biological functions and potential therapeutic applications, acts as a tumor suppressor or oncogene in cancer development. We first provide an overview and summary of the physiological function and mode of action of miR-122 in liver cancer. We will examine the various signaling pathways and molecular mechanisms through which miR-122 exerts its effects on cancer cells, including the regulation of oncogenic and tumor suppressor genes, the modulation of cell proliferation and apoptosis, and the regulation of metastasis. Most importantly, we will also discuss the potential diagnostic and therapeutic applications of miR-122 in cancer, including the development of miRNA-based biomarkers for cancer diagnosis and prognosis, and the potential use of miR-122 as a therapeutic target for cancer treatment.

MicroRNA-122 in human cancers: from mechanistic to clinical perspectives

MicroRNAs (miRNAs) are endogenous short non-coding RNAs that can regulate the expression of target genes post-transcriptionally and interact with mRNA-coding genes. MiRNAs play vital roles in many biological functions, and abnormal miRNA expression has been linked to various illnesses, including cancer. Among the miRNAs, miR-122, miR-206, miR-21, miR-210, miR-223, and miR-424 have been extensively studied in various cancers. Although research in miRNAs has grown considerably over the last decade, much is yet to be discovered, especially regarding their role in cancer therapies. Several kinds of cancer have been linked to dysregulation and abnormal expression of miR-122, indicating that miR-122 may serve as a diagnostic and/or prognostic biomarker for human cancer. Consequently, in this review literature, miR-122 has been analyzed in numerous cancer types to sort out the function of cancer cells miR-122 and enhance patient response to standard therapy.

Brain Tumors and Circulating microRNAs: A Systematic Review and Diagnostic Meta-Analysis

PURPOSE

Brain tumors (BT) are among the most prevalent cancers in recent years. Various studies have examined the diagnostic role of microRNAs in different diseases; however, their diagnostic role in BT has not been comprehensively investigated. Therefore, this meta-analysis was performed to assess microRNAs in the blood of patients with BTs accurately.

METHODS

Twenty-six eligible studies were included for analysis. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), area under curve (AUC), Q*index, summary receiver-operating characteristic (SROC) were assessed using the Meta-Disc V.1.4 and Comprehensive Meta-Analysis V.3.3 software. The Egger's test was used to evaluate publication bias in this study.

RESULTS

The diagnostic accuracy of microRNA was high in identifying BT based on the pooled sensitivity 0.82 (95% CI: 0.816 - 0.84), specificity 0.82 (95% CI: 0.817 - 0.84), PLR 5.101 (95% CI: 3.99 - 6.51), NLR 0.187 (95% CI: 0.149 - 0.236), DOR 34.07 (95% CI: 22.56 - 51.43) as well as AUC (0.92), and Q*-index (0.86). Subgroup analyses was also performed for sample types (serum/plasma), reference genes (RNU6, miR-39, and miR-24), and region to determine the diagnostic power of microRNAs in the diagnosis of BT using pooled sensitivity, specificity, PLR, NLR, AUC, and DOR.

CONCLUSION

This meta-analysis proved that circulating microRNAs were the potential markers for BT and could potentially be used as non-invasive early detection biomarkers.

Differential and Common Signatures of miRNA Expression and Methylation in Childhood Central Nervous System Malignancies: An Experimental and Computational Approach

Epigenetic modifications are considered of utmost significance for tumor ontogenesis and progression. Especially, it has been found that miRNA expression, as well as DNA methylation plays a significant role in central nervous system tumors during childhood. A total of 49 resected brain tumors from children were used for further analysis. DNA methylation was identified with methylation-specific MLPA and, in particular, for the tumor suppressor genes CASP8, RASSF1, MGMT, MSH6, GATA5, ATM1, TP53, and CADM1. miRNAs were identified with microarray screening, as well as selected samples, were tested for their mRNA expression levels. CASP8, RASSF1 were the most frequently methylated genes in all tumor samples. Simultaneous methylation of genes manifested significant results with respect to tumor staging, tumor type, and the differentiation of tumor and control samples. There was no significant dependence observed with the methylation of one gene promoter, rather with the simultaneous presence of all detected methylated genes' promoters. miRNA expression was found to be correlated to gene methylation. Epigenetic regulation appears to be of major importance in tumor progression and pathophysiology, making it an imperative field of study.

miRNA expression profiles in liver grafts of HCV and HIV/HCV-infected recipients, 6 months after liver transplantation

In hepatitis C virus (HCV)/human immunodeficiency virus (HIV) co‐infected patients, HIV enhances HCV replication and liver damage. Several microRNAs (miRNAs), active in pro‐fibrotic and inflammatory pathways, have been implicated in the pathogenesis of this phenomenon. However, these miRNAs have been tested only in explanted cirrhotic livers, when the liver damage has become chronic and irreversible. No data are available on the early phase of viral infection, such as early after liver transplantation (LT). In the present study, the expression of miR‐101, miR‐122, miR‐155, miR‐192, miR‐200c, miR‐338, and miR‐532 was determined by quantitative real‐time polymerase chain reaction in liver biopsies of HCV (n = 19) and HCV/HIV‐infected (n = 20) LT recipients, as well as in a control group (n = 18) of noninfected patients, transplanted for alcoholic cirrhosis. The timing of liver biopsy was 6 months post‐LT. None of the patients was treated with direct‐acting anti‐HCV drugs. All co‐infected recipients had suppressed HIV viral load. Grading and staging were assessed according to the Ishak Classification. HCV and HIV viral load were measured in the sera. miR‐101 (p = .03), miR‐122 (p = .012), and miR‐192 (p = .038) were significantly downregulated in HCV/HIV co‐infected and HCV mono‐infected recipients when compared with noninfected recipients, and such downregulation was more pronounced in co‐infected ones. Moreover, in co‐infected recipients but not in mono‐infected ones, miR‐101 inversely correlated with the peripheral HCV‐RNA levels (r = .41, p = .04) and miR‐122 inversely correlated with peripheral HCV‐RNA levels (r = .49, p = .03) and with the histological grading (r = .51, p = .02).  In conclusion, as early as 6 months after LT, the presence of HIV‐HCV co‐infection enhanced a significant downregulation of certain miRNAs that showed a direct correlation with HCV viral load and liver inflammation.

Altered expressions of circulating microRNAs 122 and 192 during antitubercular drug induced liver injury indicating their role as potential biomarkers

Drug induced liver toxicity is a serious health complication leading to high mortality rates and post marketing withdrawal of drugs. Although considered to be the gold standard biomarkers; aspartate aminotransferase, alanine aminotransferase, total bilirubin and alkaline phosphatase have been found to have specificities beyond liver, therefore more specific and predictive markers for the detection of antitubercular drug mediated liver damage are required. Unfortunately, the effectiveness of currently used first line antitubercular drugs namely isoniazid, rifampicin, pyrazinamide is often accompanied with liver injury, impeding the cure of patients. Keeping in view, the prognostic and diagnostic applications of microRNAs in various diseases, we tried to assess the importance of microRNAs 122 and 192 in antitubercular drug associated liver injuries. The study included subjects having tuberculosis of any type with antitubercular drug induced liver injury; naïve or newly diagnosed tuberculosis patients, tuberculosis patients on drugs not having toxicity and healthy controls. Observations from this study revealed that expression levels of miR-122 and miR-192 were significantly decreased in the serum of antitubercular drug induced liver injury patients only. Therefore, these microRNAs or the pathways associated with them can be used as a tool to predict or cure antitubercular drug associated liver injury in future.

Circulating MicroRNAs as Promising Diagnostic Biomarkers for Patients With Glioma: A Meta-Analysis

Backgrounds and Purpose: Currently, circulating microRNAs (miRNAs) are considered to be non-invasive diagnostic biomarkers in a broad range of tumors. Nevertheless, so far, miRNAs have not been fully applied to the clinic for routine screening in glioma patients. Thus, our goal is to evaluate the diagnostic performance of circulating miRNAs for gliomas via a meta-analysis. The present study is registered on the PROSPERO website, with the number CRD42020195883. Methods: Literature retrieval was implemented in the PubMed, Embase, and Web of Science databases using the established search strategy. We pooled the sensitivity, specificity, and its 95% confidence intervals (CIs) for the included studies using the Stata 14.0 software. In addition, the heterogeneity between studies was assessed via the Q statistics and I ² values calculated by a Chi-square test. A bivariate random effects model was selected due to significant heterogeneity. Specifically, for exploring the factors influencing the heterogeneity, we implemented subgroup and meta-regression analyses. Ultimately, a Deek's funnel plot asymmetry test was used to estimate the potential publication bias. Results: A total of 18 articles covering 24 studies were included, containing 2,170 glioma patients and 1,456 healthy participants. The overall pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were 0.84 (95%CI: 0.79-0.87), 0.84 (95%CI: 0.80-0.88), 5.3 (95%CI: 4.1-6.8), 0.19 (95%CI: 0.15-0.25), 27 (95%CI: 18-41), and 0.91 (95%CI: 0.88-0.93), respectively. Additionally, the findings revealed that serum miRNAs and miRNA panels presented superior diagnostic performance. Conclusion: Thus, circulating miRNAs have the potential to serve as diagnostic biomarkers for gliomas, but need to be verified via a large pool of prospective studies. Additionally, specific miRNAs still need to be elucidated in the diagnosis of a glioma, especially in the early screening stage. The findings may provide diagnostic and therapeutic strategies for the glioma population.

miRNA-21 may serve as a promising noninvasive marker of glioma with a high diagnostic performance: a pooled analysis of 997 patients

Background:

Although various serum and tissue biomarkers have been investigated for glioma diagnosis, no gold standard has been identified. miRNA-21 was demonstrated to be a promising biomarker for the diagnosis of various brain tumors, whereas there remains uncertainty concerning whether miRNA-21 could be used as a good clinical diagnostic biomarker for glioma. The current meta-analysis aimed to evaluate the diagnostic accuracy of miRNA-21 as a potent biomarker in adults with suspected glioma.

Methods:

The Pubmed and Embase databases were searched systematically from inception to January 2020 to identify relevant research reports. Pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were calculated. Summary receiver operating characteristic (SROC) curves were used to evaluate the overall diagnostic performance. Meta-regression and subgroup analyses were conducted to determine the source of heterogeneity and test the robustness of the results.

Results:

From 5394 citations with 997 subjects that met the inclusion criteria, 11 studies were selected. Summary estimates of the diagnostic performance of miRNA-21 were as follows: sensitivity, 0.83 [95% confidence interval (CI): 0.73–0.89]; specificity, 0.92 (95% CI: 0.85–0.96); PLR, 10.20 (95% CI: 5.10–20.30); NLR, 0.19 (95% CI: 0.12–0.31); and DOR, 54 (95% CI: 19–155). The area under the SROC curve was 0.94 (95% CI: 0.92–0.96). Deeks’s funnel plot revealed no evidence of publication bias (p = 0.59). Meta-regression analysis suggested that study publication year could attribute to the heterogeneity. Subgroup analysis found miRNA-21 had a constant high diagnostic accuracy across different ethnicity, glioma grade, sample source, and study region.

Conclusion:

This meta-analysis demonstrated that miRNA-21 has high diagnostic performance and could serve as a promising noninvasive diagnostic marker for glioma. Further large prospective studies are needed to validate its diagnostic value and its prognostic significance and therapeutic effects.

Time to focus on circulating nucleic acids for diagnosis and monitoring of gliomas: A systematic review of their role as biomarkers

Gliomas are diffusely growing tumours arising from progenitors within the central nervous system. They encompass a range of different molecular types and subtypes, many of which have a well-defined profile of driver mutations, copy number changes and DNA methylation patterns. A majority of gliomas will require surgical intervention to relieve raised intracranial pressure and reduce tumour burden. A proportion of tumours, however, are located in neurologically sensitive areas and a biopsy poses a significant risk of a deficit. A majority of gliomas recur after surgery, and monitoring tumour burden of the recurrence is currently achieved by imaging. However, most imaging modalities have limitations in assessing tumour burden and infiltration into adjacent brain, and sometimes imaging is unable to discriminate between tumour recurrence and pseudo-progression. Liquid biopsies, obtained from body fluids such as cerebrospinal fluid or blood, contain circulating nucleic acids or extracellular vesicles containing tumour-derived components. The studies for this systematic review were selected according to PRISMA criteria, and suggest that the detection of circulating tumour-derived nucleic acids holds great promises as biomarker to aid diagnosis and prognostication by monitoring tumour progression, and thus can be considered a pathway towards personalized medicine.

As Evidence-Based Tumorigenic Role of Epstein-Barr Virus miR-BART1-3p in Neurological Tumors

INTRODUCTION

Central nervous system tumors are a diverse group of tumors that account for 2% of all adult cancers and 17% of childhood malignancies. Several internal and external risk factors are involved in the development of this cancer such as viral infections. The aim of this study was to the determination of the EBV infection frequency and the expression level of miR-122 and miR-BART in CNS tumors samples.

METHODS

One hundred and thirty-eight  fresh tissue sample (106 case and 32 control) was collected from CNS specimens. The presence of Epstein-Barr virus (EBV) DNA was examined by PCR assay and the expression level of miR-122 and miR-BART were evaluated by using real-time PCR assay in CNS tissue samples.

RESULTS

EBV DNA was detected in 17% (18 of 106) of tumors tissue samples and 6.4% (2 of 32) of control samples. according to results, there was a significant relationship between the presence of EBV-DNA with CNS tumors. Additionally, the expression level of miR-122 was significantly downregulated in the EBV-positive sample compared to that of the EBV-negative sample. Also, the level of EBV-BART1-3p expression was significantly higher in EBV-positive tumors samples than EBV-positive normal samples.

CONCLUSION

The results of this study suggest that the EBV could change the condition of cancer cells by altering the expression of miR-122 and EBV-BART1-3p and maybe contribute to the development of cancer cells. However, the role of viral infections in CNS cancer requires further studies. <br />.

Comprehensive Characterization of Nanosized Extracellular Vesicles from Central and Peripheral Organs : Implications for Preclinical and Clinical Applications

Extracellular vesicles (EV) are nano-sized vesicles that have been garnering a lot of attention for their valuable role as potential diagnostic markers and therapeutic vehicles for a plethora of pathologies. Whilst EV markers from biofluids such as plasma, serum, urine, cerebrospinal fluid and in vitro cell culture based platforms have been extensively studied, a significant knowledge gap that remains is the characterization of specific organ derived EVs (ODE). Here, we present a standardized protocol for isolation and characterization of purified EV isolated from brain, heart, lung, kidney and liver from rat and postmortem human tissue. Next, using quantitative mass spectrometry based proteomics, we characterized the respective tissue EV proteomes that identified synaptophysin (SYP), caveolin-3 (CAV3), solute carrier family 22 member 2 (SLC22A2), surfactant protein B (SP-B), and fatty acid-binding protein 1 (FABP1) as potential markers for the brain, heart, kidney, lung, and liver-EV, respectively. These respective tissue specific markers were further validated using both immunoblotting and a nanoplasmonic platform- single EV imaging analysis in the two species. To summarize, our study for the first time using traditional biochemical and high precision technology platforms provide a valuable proof of concept approach in defining specific ODE markers which further could be developed as potential therapeutic candidates for respective end-organ associated pathologies.

Clinical significance of miR-33b in glioma and its regulatory role in tumor cell proliferation, invasion and migration

Background: This study aimed to investigate the clinical significance of microRNA-33b (miR-33b) in glioma patients and its biological function in tumor progression. Materials & methods: Expression of miR-33b was measured using quantitative real-time RT-PCR. Diagnostic and prognostic values of miR-33b were assessed by the receiver operating characteristics curve and Kaplan-Meier (KM) survival assay. The functional role of miR-33b was further analyzed. Results: Expression of miR-33b in glioma patients and cells was decreased. Expression of miR-33b had high diagnostic accuracy and could predict a poor prognosis. Overexpression of miR-33b led to suppressed glioma cell proliferation, migration and invasion. Conclusion: Decreased expression of miR-33b serves a promising biomarker in the diagnosis and prognosis of glioma, and may be a potential therapeutic target.

Beta-Amyloid-Dependent miRNAs as Circulating Biomarkers in Alzheimer's Disease: a Preliminary Report

MicroRNAs (miRNAs) are considered among the most reliable biomarkers to diagnose and predict Alzheimer's disease (AD), due to their regulatory nature. The main goal of this study was to evaluate the expression of miR4422 and miR3714, as the main regulators of GSAP and BACE1 expression, in AD patients compared with healthy subjects. Twenty patients with a mild to moderate AD (58-71 years old) and 15 healthy subjects (58-73 years old) participated in this study. The expression levels of miR4422 and miR3714 as the target genes and 5S rRNA and miRlet7a-5p as the reference genes were measured in the two groups. To compare the expression between the case and the control groups, the t test or the Wilcoxon test was used, based on the data distribution patterns. The efficiencies of amplification of the miR4422, miR3714, 5S rRNA, and miRlet7a-5p genes all were in the acceptable range. The mean miR4422-5S rRNA dCt value was significantly different between the two groups (p = 0.018). The relative fold change of the expression was 0.43. The mean miR4422-miRlet7a-5p dCt value (p = 0.41), the mean miR3714-5S rRNA dCt value (p = 0.10), and the mean miR3714-miRlet7a-5p dCt value (p = 0.063) were not significantly different between the two groups. We indicated that miR4422 could be a reliable biomarker for Alzheimer's diagnosis. It seems that the reduced expression of miR4422 that targets GSAP and BACE1 expression can lead to an increase in the formation of Aβ plaque.

Serum exosomal miR-122 as a potential diagnostic and prognostic biomarker of colorectal cancer with liver metastasis

Background: Liver is the most common site for metastatic spread of CRC at the time of diagnosis which leads to high mortality. This study aimed to identify novel circulating exosomal miRNAs as biomarkers of colorectal cancer (CRC) with liver metastasis (LM).

Materials and methods: Candidate miRNAs were selected through integrated analysis of Gene Expression Omnibus (GEO) database as well as clinical samples. Exosomes isolated from serum and cultured media were identified by using transmission electron microscopy (TEM) and western blot. The expression levels and diagnostic value of candidate miRNAs were further tested and validated through qRT-PCR and receiver operating characteristic curve (ROC) analysis. The association of candidate miRNA expressions with patients' prognosis was analyzed with logistic regression and Cox proportional hazards regression models.

Results: After integrated analysis of three GEO datasets and clinical samples, miR-122 was discovered to be remarkably overexpressed in tissues of CRC patients. Then we revealed that elevated serum miR-122 was tumor-derived by being packaged into exosomes. The expressions of serum exosomal miR-122 were significantly upregulated in CRC patients, especially in those with LM. Serum exosomal miR-122 expressions could differentiate CRC patients with LM from healthy controls and patients without LM with area under the ROC curve (AUC) of 0.89 and 0.81. Uni- and multivariate logistic regression showed that serum exosomal miR-122 was an independent prognostic indicator of CRC patients.

Conclusions: Serum exosomal miR-122 was a novel potential diagnostic and prognostic biomarker in CRC patients with LM.

Prediction of miRNA interaction with mRNA of stroke candidate genes

BACKGROUND

The role of miRNA in tissue affected by stroke is actively studied, but it remains unclear which miRNAs and target genes are involved in the development of stroke.

METHODS

The MirTarget program defines the following features of a miRNA binding to a mRNA: the binding start site, the location of the binding site in mRNA, the free energy of a miRNA binding with a mRNA, and the interaction schemes of miRNA and mRNA.

RESULTS

The interaction of 6565 miRNAs with mRNAs of stroke candidate genes was determined. The association of the mRNAs of stroke candidate genes with miRNAs depends on the level of gene expression. Some highly expressed candidate genes are targets of miR-619-5p and miR-5095, which have binding sites located on overlapping mRNA nucleotide sequences (clusters). miR-619-5p and miR-5095 bind to mRNA of 15 genes. Clusters for the binding of miR-1273f,d,e are in mRNAs of highly expressed genes. The start sites of miR-1273d and miR-1273e binding in all clusters are in sequences with one and ten nucleotides, respectively. The clusters of multiple miR-574-5p and ID00470.5p-miR binding sites and the clusters of the miR-466, ID01030.3p-miR, and ID00436.3p-miR binding sites are in mRNAs of some genes expressed at low levels.

CONCLUSION

The organization of miRNA binding sites into clusters reduces the length of mRNA and creates competition between miRNAs for binding to mRNA of a target gene. The characteristics of miRNA associations with target genes can be used to recommend markers for a diagnosis of stroke.

Potential diagnostic and prognostic value of plasma long noncoding RNA LINC00086 and miR-214 expression in gastric cancer

BACKGROUND

Plasma carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and cancer antigen 72-4 (CA72-4) are common markers which are useful in the diagnosis and prognosis of GC. However, their sensitivity and specificity in GC remain unsatisfactory. Identification of cancer diagnosed-biomarkers would be of great value.

OBJECTIVE

Evaluate the diagnostic and prognostic value of LINC00086 and miR-214 in GC.

METHODS

In this study, we determined the expression of LINC00086 and miR-214 in GC by qRT-PCR. Additionally, we investigated the relationship between various clinicopathological features of GC patients and LINC00086 or miR-214 expression, and evaluated the diagnostic and prognostic value of LINC00086 and miR-214 in GC.

RESULTS

In this study, we found that plasma LINC00086 expression was significantly lower, whereas plasma miR-214 expression was significantly higher in GC patients than in normal individuals. LINC00086 and miR-214 exhibited high sensitivity and specificity in diagnosing GC. Additionally, GC patients with low LINC00086 or high miR-214 expression were likely to have larger tumors, lymphatic metastasis, larger TNM stage, and higher CEA and CA19-9 levels. Moreover, GC patients with low LINC00086 or high miR-214 expression showed lower survival rates. Lymphatic metastasis, LINC00086, and miR-214 are independent factors affecting patient diagnosis.

CONCLUSIONS

LINC00086 and miR-214 are potentially diagnostic and prognostic markers for GC.

MicroRNA based theranostics for brain cancer: basic principles

BACKGROUND

Because of the complexity of the blood-brain barrier (BBB), brain tumors, especially the most common and aggressive primary malignant tumor type arising from the central nervous system (CNS), glioblastoma, remain an essential challenge regarding diagnostic and treatment. There are no approved circulating diagnostic or prognostic biomarkers, nor novel therapies like immune checkpoint inhibitors for glioblastoma, and chemotherapy brings only minimal survival benefits. The development of molecular biology led to the discovery of new potential diagnostic tools and therapeutic targets, offering the premise to detect patients at earlier stages and overcome the current poor prognosis.

MAIN BODY

One potential diagnostic and therapeutic breakthrough might come from microRNAs (miRNAs). It is well-known that miRNAs play a role in the initiation and development of various types of cancer, including glioblastoma. The review aims to answer the following questions concerning the role of RNA theranostics for brain tumors: (1) which miRNAs are the best candidates to become early diagnostic and prognostic circulating biomarkers?; (2) how to deliver the therapeutic agents in the CNS to overcome the BBB?; (3) which are the best methods to restore/inhibit miRNAs?

CONCLUSIONS

Because of the proven roles played by miRNAs in gliomagenesis and of their capacity to pass from the CNS tissue into the blood or cerebrospinal fluid (CSF), we propose miRNAs as ideal diagnostic and prognostic biomarkers. Moreover, recent advances in direct miRNA restoration (miRNA mimics) and miRNA inhibition therapy (antisense oligonucleotides, antagomirs, locked nucleic acid anti-miRNA, small molecule miRNA inhibitors) make miRNAs perfect candidates for entering clinical trials for glioblastoma treatment.

Cell-free microRNAs as non-invasive biomarkers in glioma: a diagnostic meta-analysis

Objective:

Since the diagnostic value of microRNAs for detecting glioma is contentious, we aimed to carry out a meta-analysis to synthetically evaluate the diagnostic significance of cell-free microRNAs in cerebrospinal fluid and blood in the detection of glioma.

Methods:

A systematic document retrieval of public databases was performed to obtain eligible studies. Specificity was applied to draw the summary receiver operator characteristic (SROC) curve against sensitivity, and the pooled diagnostic efficiency was assessed by generating the area under the SROC curve. Meta-regression and subgroup analyses were utilized to explore the latent sources of heterogeneity. STATA 12.0, RevMan 5.3 and Meta-DiSc 1.4 were used to conduct all statistical analyses.

Results:

A total of 47 studies from 20 articles comprising 2262 glioma patients and 1986 controls were included in our meta-analysis. Cell-free microRNAs exhibited relatively good diagnostic efficiency in glioma detection, with a sensitivity of 0.83, a specificity of 0.87, and an area under the curve of 0.91. Cell-free miR-21 performed best with pooled area under the curve of 0.88, followed by miR-125 and miR-222. Subgroup analyses and meta-regression indicated that there was substantial heterogeneity existing among the studies, which was in part caused by sample size, World Health Organization grade, reference gene, microRNA origin (extracellular vesicles or non-extracellular vesicle-based-microRNA), microRNA profiling (single- or multiple-microRNA), specimen types, and ethnicity.

Conclusions:

Cell-free microRNAs in cerebrospinal fluid and blood may play an important role as promising non-invasive biomarkers in the early diagnosis of glioma. Further comprehensive forward-looking research is required to validate their clinical significance in glioma diagnosis.

Clinical value of miRNA-122 in the diagnosis and prognosis of various types of cancer

The present study aimed to systematically analyze the value of microRNA-122 (miRNA-122) in the diagnosis and prognosis of hepatocellular carcinoma (HCC) and other types of cancer. First, the reverse transcription-quantitative polymerase chain reaction method was used to detect the expression levels of miRNA-122 in the serum samples of patients with HCC, benign lesions and healthy volunteers. Next, miRNA-seq data of miRNA-122 from The Cancer Genome Atlas database were used to analyze the differential expression and overall survival rate associated with a variety of types of cancer. Meanwhile, the target gene prediction of miRNA-122 was performed using four different software programs. Finally, 353 significant target genes were identified for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis. Finally, it was demonstrated that the expression levels of miRNA-122 in the HCC group were increased compared with the healthy group (P<0.001), but decreased with respect to the benign group (P<0.001). In addition, the combination of the miRNA-122 and a fetoprotein may further improve the diagnostic accuracy between the HCC and healthy groups (area under the curve, 0.980; 95% confidence interval, 0.958–1.000). It was also demonstrated that miRNA-122 exhibited significantly differential expression and the overall survival rate was predicted for various other types of cancer, including colorectal cancer, renal carcinoma, cholangiocarcinoma, prostate cancer and thyroid carcinoma. Functional enrichment analysis demonstrated that the target genes of miRNA-122 may contribute to the composition of the nucleus and cytoplasm, and regulate a variety of biological processes, including cardiac muscle cell differentiation and glucose metabolic processes via protein biosynthesis, estrogen and glucagon associated signaling pathways. These results revealed that miRNA-122 may be an indispensable biomarker for the diagnosis, prognostic evaluation and targeted therapy in pan-cancer.

Liquid biopsy for pediatric central nervous system tumors

Central nervous system (CNS) tumors are the most common solid tumors in children, and the leading cause of cancer-related death. Over the past decade, molecular profiling has been incorporated into treatment for pediatric CNS tumors, allowing for a more personalized approach to therapy. Through the identification of tumor-specific changes, it is now possible to diagnose, assign a prognostic subgroup, and develop targeted chemotherapeutic treatment plans for many cancer types. The successful incorporation of informative liquid biopsies, where the liquid biome is interrogated for tumor-associated molecular clues, has the potential to greatly complement the precision-based approach to treatment, and ultimately, to improve clinical outcomes for children with CNS tumors. In this article, the current application of liquid biopsy in cancer therapy will be reviewed, as will its potential for the diagnosis and therapeutic monitoring of pediatric CNS tumors.

MicroRNAs as potential biomarkers for the diagnosis of glioma: A systematic review and meta-analysis

Glioma is the most common central nervous system tumor and associated with poor prognosis. Identifying effective diagnostic biomarkers for glioma is particularly important in order to guide optimizing treatment. MicroRNAs (miRNAs) have drawn much attention because of their diagnostic value in diverse cancers, including glioma. We summarized studies to identify the potential diagnostic values of miRNAs in glioma patients. We included articles reporting miRNAs for differentiation of glioma patients from controls. We calculated sensitivities, specificities, and area under the curves (AUC) of individual miRNA and miRNA panels. We found that overall sensitivity, specificity, and AUC of miRNAs in diagnosis of glioma were 85% (95% confidence interval [CI]: 0.81-0.89), 90% (95% CI 0.85-0.93), and 93% (95% CI 0.91-0.95), respectively. Meta-regression analysis showed that the detection of miRNAs expression in cerebrospinal fluid (CSF) and brain tissue largely improved the diagnostic accuracy. Likewise, panels of multiple miRNAs could enhance the pooled sensitivity. Moreover, AUC of miR-21 was 0.88, with 86% sensitivity and 94% specificity. This study demonstrated that miRNAs could function as potential diagnosis markers in glioma. Detection of miRNAs in CSF and brain tissue displays high accuracy in the diagnosis of glioma.