The miR-17-92 cluster as a potential biomarker for the early diagnosis of gastric cancer: evidence and literature review

Gastric Intestinal Metaplasia: Challenges and the Opportunity for Precision Prevention

GIM is a persistent, premalignant lesion whereby gastric mucosa is replaced by metaplastic mucosa resembling intestinal tissue, arising in the setting of chronic inflammation, particularly in the context of Helicobacter pylori. While the overall rates of progression to gastric adenocarcinoma are low, estimated at from 0.25 to 2.5%, there are features that confer a much higher risk and warrant follow-up. In this review, we collate and summarise the current knowledge regarding the pathogenesis of GIM, and the clinical, endoscopic and histologic risk factors for cancer. We examine the current state-of-practice with regard to the diagnosis and management of GIM, which varies widely in the published guidelines and in practice. We consider the emerging evidence in population studies, artificial intelligence and molecular markers, which will guide future models of care. The ultimate goal is to increase the detection of early gastric dysplasia/neoplasia that can be cured while avoiding unnecessary surveillance in very low-risk individuals.

Exosomal noncoding RNAs in colorectal cancer: An overview of functions, challenges, opportunities, and clinical applications

Colorectal cancer (CRC) is the third most threatening malignancy worldwide. Colorectal tumors transfer information with their tumor microenvironment (TME) and communicate together which can be detected through exosome transmission. Exosomes are important regulators made by different types of cells in all body fluids containing RNA, DNA, metabolites, and proteins. Recently, Exosome-derived noncoding RNAs (ncRNAs) applications have gained great consideration based on their potential role in the different pathological processes. Therefore, in this review, we summarized the recent discoveries on exosomal ncRNAs function in CRC initiation and development, and drug resistance to provide a novel insight into exosomal ncRNAs' clinical application and their potential to be biomarkers for CRC patients.

Cancer Stem Cells in Tumor Microenvironment of Adenocarcinoma of the Stomach, Colon, and Rectum

Simple Summary

Gastrointestinal cancers have a high mortality rate worldwide, and the progression of the disease is related to cancer stem cells. Until now, its relationship with the microenvironment has been poorly understood. We describe the molecules and different pathways activated during this interaction and the new targeting therapies for cancer cells and microenvironment modulation. This approach could impact the way gastrointestinal cancers are managed.

Abstract

Gastrointestinal adenocarcinomas are one of the world’s deadliest cancers. Cancer stem cells and the tissue microenvironment are highly regulated by cell and molecular mechanisms. Cancer stem cells are essential for maintenance and progression and are associated with resistance to conventional treatments. This article reviews the current knowledge of the role of the microenvironment during the primary establishment of gastrointestinal adenocarcinomas in the stomach, colon, and rectum and its relationship with cancer stem cells. We also describe novel developments in cancer therapeutics, such as targeted therapy, and discuss the advantages and disadvantages of different treatments for improving gastrointestinal cancer prognosis.

Bile reflux and bile acids in the progression of gastric intestinal metaplasia

ABSTRACT

Gastric intestinal metaplasia (GIM) is a precancerous lesion of gastric cancer (GC) and is considered an irreversible point of progression for GC. Helicobacter pylori infection can cause GIM, but its eradication still does not reverse the process. Bile reflux is also a pathogenic factor in GIM and can continuously irritate the gastric mucosa, and bile acids in refluxed fluid have been widely reported to be associated with GIM. This paper reviews in detail the relationship between bile reflux and GIM and the mechanisms by which bile acids induce GIM.

Coding and non-coding co-expression network analysis identifies key modules and driver genes associated with precursor lesions of gastric cancer

BACKGROUND

Helicobacter pylori infection is the most important risk factor for gastric cancer (GC). Human gastric adenocarcinoma develops after long-term H. pylori infection via the Correa cascade. This carcinogenic pathway describes the progression from gastritis to atrophy, intestinal metaplasia (IM), dysplasia and GC. Patients with atrophy and intestinal metaplasia are considered to have precancerous lesions of GC (PLGC). H. pylori eradication and endoscopy surveillance are currently the only interventions for preventing GC. Better knowledge of the biology of human PLGC may help find stratification markers and contribute to better understanding of biological mechanisms. One way to achieve this is by using co-expression network analysis. Weighted gene co-expression network analysis (WGCNA) is often used to identify modules from co-expression networks and relate them to clinical traits. It also allows identification of driver genes that may be critical for PLGC.

AIM

The purpose of this study was to identify co-expression modules and differential gene expression in dyspeptic patients at different stages of the Correa pathway.

METHODS

We studied 96 gastric biopsies from 78 patients that were clinically classified as: non-active (n = 10) and chronic-active gastritis (n = 20), atrophy (n = 12), and IM (n = 36). Gene expression of coding RNAs was determined by microarrays and non-coding RNAs by RNA-seq. The WGCNA package was used for network construction, module detection, module preservation and hub and driver gene selection.

RESULTS

WGCNA identified 20 modules for coding RNAs and 4 for each miRNA and small RNA class. Modules were associated with antrum and corpus gastric locations, chronic gastritis and IM. Notably, coding RNA modules correlated with the Correa cascade. One was associated with the presence of H. pylori. In three modules, the module eigengene (ME) gradually increased in the stages toward IM, while in three others the inverse relationship was found. One miRNA module was negatively correlated to IM and was used for a mRNA-miRNA integration analysis. WGCNA also uncovered driver genes. Driver genes show both high connectivity within a module and are significantly associated with clinical traits. Some of those genes have been previously involved in H. pylori carcinogenesis, but others are new. Lastly, using similar external transcriptomic data, we confirmed that the discovered mRNA modules were highly preserved.

CONCLUSION

Our analysis captured co-expression modules that provide valuable information to understand the pathogenesis of the progression of PLGC.

MicroRNA-20a-5p Downregulation by Atorvastatin: A Potential Mechanism Involved in Lipid-Lowering Therapy

The treatment of hypercholesterolemia is mainly based on statins. However, the response to pharmacological therapy shows high inter-individual variability, resulting in variable effects in both lipid lowering and risk reduction. Thus, a better understanding of the lipid-lowering mechanisms and response variability at the molecular level is required. Previously, we demonstrated a deregulation of the microRNA expression profile in HepG2 cells treated for 24 h with atorvastatin, using a microarray platform. In the present study, we evaluated the expression of hsa-miR-17-5p, hsa-miR-20a-5p and hsa-miR-106a-5p in hypercholesterolemic patients before and after atorvastatin treatment and in HepG2 cells treated for 24 h with atorvastatin The miRNA hsa-mir-20a-5p was repressed after atorvastatin treatment in hypercholesteremic subjects and in HepG2 cells in culture. Repression of hsa-mir-20a-5p increased LDLR gene and protein expression in HepG2 cells, while hsa-mir-20a-5p overexpression reduced LDLR gene and protein expression.

Downregulated miR-18a and miR-92a synergistically suppress non-small cell lung cancer via targeting Sprouty 4

As a novel noncoding RNA cluster, miR-17-92 cluster include six members: miR-17, miR-18a, miR-19a, miR-19b-1, miR-20a, and miR-92a. Dysregulation of miR-17-92 has been proved to be connected with the advancement of a series of human diseases, but the roles of miR-17-92 cluster in non-small cell lung cancer (NSCLC) have not been absolutely elaborated. Herein, we determined that miR-17-92 cluster were upregulated significantly in NSCLC tissues, and the cell proliferation, migration and cycle progression of NSCLC were also facilitated under the function of miR-17-92 cluster. Sprouty 4 (SPRY4) was a direct target of miR-92a, and its overexpression restrained the exacerbation of NSCLC induced by miR-92a. Furthermore, the tumor xenograft assay showed that miR-92a facilitated tumor growth by inhibiting the expression of SPRY4 and mediating Epithelial-Mesenchymal Transition (EMT) in vivo. Finally, we looked into the synergistic effects of miR-92a and miR-18a on NSCLC, and found that antagomiR-18a treatment arrested the tumor growth rate of xenografted mice markedly.

Designing strategies of small-molecule compounds for modulating non-coding RNAs in cancer therapy

Non-coding RNAs (ncRNAs) have been defined as a class of RNA molecules transcribed from the genome but not encoding proteins, such as microRNAs, long non-coding RNAs, Circular RNAs, and Piwi-interacting RNAs. Accumulating evidence has recently been revealing that ncRNAs become potential druggable targets for regulation of several small-molecule compounds, based on their complex spatial structures and biological functions in cancer therapy. Thus, in this review, we focus on summarizing some new emerging designing strategies, such as high-throughput screening approach, small-molecule microarray approach, structure-based designing approach, phenotypic screening approach, fragment-based designing approach, and pharmacological validation approach. Based on the above-mentioned approaches, a series of representative small-molecule compounds, including Bisphenol-A, Mitoxantrone and Enoxacin have been demonstrated to modulate or selectively target ncRNAs in different types of human cancers. Collectively, these inspiring findings would provide a clue on developing more novel avenues for pharmacological modulations of ncRNAs with small-molecule drugs for future cancer therapeutics.

A Panel of Circulating microRNAs as a Potential Biomarker for the Early Detection of Gastric Cancer

Background

The high mortality rate of Gastric Cancer (GC) is a consequence of delayed diagnosis. The early diagnosis of GC could increase the five-year survival rate among patients. We aimed to find a panel of microRNAs (miRNA) for the detection of GC in the early stages.

Methods

In this case-control study, we selected consistently upregulated miRNAs from the results of 12 high-throughput miRNA profiling studies in GC. In the profiling phase, the differential expressions of 13 candidate miRNAs were analyzed by quantitative reverse-transcription PCR (qRT-PCR) in two pooled RNA samples prepared from the plasma of eight GC patients and eight matched controls. In the validation phase, significantly upregulated miRNAs from the profiling phase were further evaluated in the plasma samples of 97 patients with stage I-IV gastric adenocarcinoma and 100 healthy controls.

Results

In the profiling phase, six miRNAs (miR-18a, 21, 25, 92a, 125b and 221) were significantly upregulated in the GC patients compared to the controls (p<0.05). However, in the validation phase, only significant up-regulation of miR-18a, 21 and 125b was confirmed (p<0.05). A panel of miR-18a/21/125b was able to detect GC patients with stage I-IV from the controls (p<0.001; AUC=0.92, sensitivity=86%; specificity=85%). In addition, the panel could distinguish the early-stage GC (I+II) from the control group with an AUC of 0.83, a sensitivity of 83%, and a specificity of 75%.

Conclusion

A panel of circulating miR18a/21/125b could be suggested as a potential biomarker for the early detection of GC.

miR-17 acts as a tumor suppressor by negatively regulating the miR-17-92 cluster

Anaplastic thyroid cancer (ATC) is an aggressive, highly metastatic cancer that expresses high levels of the microRNA (miR)-17-92 cluster. We employ an miR inhibitor system to study the function of the different miRs within the miR-17-92 cluster based on seed sequence homology in the ATC SW579 cell line. While three of the four miR-17-92 families were oncogenic, we uncovered a novel role for miR-17 as a tumor suppressor in vitro and in vivo. Surprisingly, miR-17 inhibition increased expression of the miR-17-92 cluster and significantly increased the levels of the miR-18a and miR-19a mature miRs. miR-17 inhibition increased expression of the cell cycle activator CCND2, associated with increased cell proliferation and tumor growth in transplanted SW579 cells in xenograft mice. miR-17 regulates MYCN and c-MYC expression in SW579 cells, and the inhibition of miR-17 increased MYCN and c-MYC expression, which increased pri-miR-17-92 transcripts. Thus, inhibition of miR-17 activated the expression of the oncogenic miRs, miR-18a and miR-19a. While many cancers express high levels of miR-17, linking it with tumorigenesis, we demonstrate that miR-17 inhibition does not inhibit thyroid tumor growth in SW579 and MDA-T32 ATC cells but increases expression of the other miR-17-92 family members and genes to induce cancer progression.

Molecular Landscapes of Gastric Pre-Neoplastic and Pre-Invasive Lesions

Gastric carcinoma (GC) represents one of the most common and most lethal malignancies worldwide. The histopathological characterization of GC precursor lesions has provided great knowledge about gastric carcinogenesis, with the consequent introduction of effective strategies of primary and secondary prevention. In recent years, a large amount of data about the molecular events in GC development is emerging, flanking the histomorphological descriptions. In this review, we describe the landscape of molecular alterations in gastric pre-invasive lesions with a glance at their potential use in the diagnostic and therapeutic decision-making process.

Expression Profile of miRNA-17-3p and miRNA-17-5p Genes in Gastric Cancer Patients with Helicobacter pylori Infection

BACKGROUND

The most common chronic bacterial infection is Helicobacter pylori. The connection between chronic H. pylori infection and gastric cancer is recognized. The early detection of gastric cancer improves survival. miRNAs regulate gene expression in eukaryotes by inhibiting mRNA translocation or degradation. The objective of this study was to compare the expression of miRNA-17-3p and miRNA-17-5p genes in gastric cancer patients with Helicobacter pylori infection.

METHODS

Herein, 30 isolates were identified as H. pylori based on urease test, and 30 and 12 cases were isolated from gastric cancer patients and non-Helicobacter pylori cases as control, respectively. A peripheral blood sample was collected from patients. Analysis of total mRNA extracts from peripheral blood samples, for gene expression changes (miRNA-17-3p and miRNA-17-5p) by quantitative real-time polymerase chain reaction (qRT-PCR), was done.

RESULTS

As said by the results, p values showed that expression levels of miRNA-17-3p and miRNA-17-5p were significantly higher in H. pylori-positive GC patients and H. pylori-positive non-GC patients with comparing by healthy controls. So, there was no significant difference between expression levels of miRNA-17-3p and miRNA-17-5p in H. pylori-positive GC patients and H. pylori-positive non-GC patients.

CONCLUSION

Considering our results, the high expression of miRNA-17-3p and miRNA-17-5p has a direct relationship with increased cell proliferation, inhibition of tumor cell apoptosis and tumor angiogenesis, in addition to miRNAs play an important role as biomarkers in helping for detection of the patient by H. pylori infection to become cancerous. Therefore, it can be used to make specific diagnostic kits and to treat patients.

Expression and clinical significance of miR-338 and miR-20a in serum of patients with gastric carcinoma

OBJECTIVE

This research intended to explore the content and the role of miR-338 and miR-20a in the serum of patients with gastric carcinoma (GC).

METHODS

Sixty-seven patients with GC, diagnosed and treated for the first time in our hospital from February 2014 to October 2016 were selected as the observation group (OG), and 45 healthy people were selected as the control group (CG). miR-338 and miR-20a of the CG and the OG were tested using qRT-PCR, and the correlation between the two indexes was analyzed by Pearson test. The diagnostic value of miR-338 and miR-20a in GC was analyzed by receiver operating characteristic curve (ROC). The correlation of miR-338 and miR-20a with clinical data was compared, and the correlation of the two with the survival of patients was observed. The independent prognostic factors in patients with GC were analyzed by Cox regression.

RESULTS

miR-338 expression was low in GC patients' serum, while miR-20a was high in GC patients. The expression of the two indexes was negatively correlated (r=-0.609, P<0.001). The areas under the curve of miR-338 and miR-20a were 0.849 and 0.865 respectively. Low expression of miR-338 and high expression of miR-20a were correlated to large tumors, low differentiation degree, high possibility of lymph node metastasis, and late TNM stage of GC patients. Multivariate Cox results revealed that tumor size, lymph node metastasis, differentiation degree, TNM stage, miR-338 and miR-20a were independent prognostic factors.

CONCLUSION

miR-338 and miR-20a are expected to be serological indicators for GC diagnosis and prognosis.

Molecular Alterations in Gastric Intestinal Metaplasia

Gastric cancer (GC) remains one of the most common causes of mortality worldwide. Intestinal metaplasia (IM) is one of the preneoplastic gastric lesions and is considered an essential predisposing factor in GC development. Here we present a review of recent most relevant papers to summarize major findings on the molecular alterations in gastric IM. The latest progress in novel diagnostic methods allows scientists to identify various types of molecular alterations in IM, such as polymorphisms in various genes, changes in the expression of micro-RNAs and long noncoding RNAs, and altered microbiome profiles. The results have shown that some of these alterations have strong associations with IM and a potential to be used for screening, treatment, and prognostic purposes; however, one of the most important limiting factors is the inhomogeneity of the studies. Therefore, further large-scale studies and clinical trials with standardized methods designed by multicenter consortiums are needed. As of today, various molecular alterations in IM could become a part of personalized medicine in the near future, which would help us deliver a personalized approach for each patient and identify those at risk of progression to GC.

DHA Abolishes the Detrimental Effect of Docetaxel on Downregulation of the MICA via Decreasing the Expression Level of MicroRNA-20a in Gastric Cancer

BACKGROUND

MHC class I chain-related protein A (MICA) is a membrane glycoprotein expressed abnormally on some malignant cells including gastric cancer (GC) cell and elicits anti-tumor immune responses. Downregulation of MICA expression could lead to immune-evasion of cancer cells.

OBJECTIVE(S)

In this study, we aimed to investigate the effect of docosahexaenoic acid (DHA) and docetaxel alone or in combination on the expression level of MICA and its regulating microRNA (miRNA), miR-20a in MKN45 GC cell line.

METHOD(S)

MKN45 GC cell line was cultured and MTT assay was performed to determine IC50 of docetaxel. Cells were treated by 18.5 μM docetaxel and 100 μM DHA. After that, RNA extraction and cDNA synthesis were done and the expression level of MICA and miR-20a were determined by quantitative real-time PCR for both treated and untreated cell lines.

RESULTS

Our findings showed less downregulation of the expression level of MICA by the combination of docetaxel/DHA (5.34-fold) compared with docetaxel (45.45-fold) and DHA (55.55-fold). Consistently, combination therapy led to the more downregulation of the expression level of the miR-20a (5.20-fold) in comparison to docetaxel (2.38-fold) and DHA (1.60-fold).

CONCLUSION(S)

As an unwanted effect of docetaxel therapy in GC, downregulation of MICA expression could lead to weak anti-tumor immune responses. By increasing the expression level of MICA, combination therapy of docetaxel with DHA would be useful to overcome this side effect.

MiR-484 suppressed proliferation, migration, invasion and induced apoptosis of gastric cancer via targeting CCL-18

Gastric cancer is a common and high-incidence malignant gastro-intestinal cancer that seriously threatens human life. Evidence suggests that microRNAs (miRNAs) play an essential role in regulating the occurrence and development of gastric cancer, but the possible mechanisms and effects remain to be further explored. In the present study, a new tumour suppresser function of miR-484 was identified in gastric cancer. The expression of miR-484 was obviously decreased, and the expression of CCL-18 was obviously increased in gastric cancer tissues and cell lines. In addition, upregulation of miR-484 suppressed cell proliferation, migration and invasion, and induced cell cycle arrest in G1 phase and cell apoptosis in gastric cancer cells. Besides, miR-484 mimics could block the PI3K/AKT signalling pathway. Moreover, CCL-18 was confirmed as a direct target of miR-484 by binding its 3'-UTR, and over-expression of CCL-18 could restore the effects of miR-484 on the growth and metastasis of gastric cancer. Finally, in vivo experiments showed that over-expression of miR-484 inhibited the subcutaneous tumorigenicity of gastric cancer cells, and the inhibition was blocked after over-expression of CCL-18. To conclude, miR-484 expression was downregulated in gastric cancer tissues and cells and played an anti-cancer role in the occurrence and development of gastric cancer, which may be achieved by inhibiting the expression of transcription factor CCL-18 and blocking the PI3K/AKT pathway.

An insight into the roles of piRNAs and PIWI proteins in the diagnosis and pathogenesis of oral, esophageal, and gastric cancer

P-Element induced wimpy testis (PIWI)-interacting RNA (piRNA) is a member of the non-coding RNAs family. Four PIWI proteins are found to be expressed in humans. The number of studies focusing on the roles of piRNAs and PIWI proteins in the field of cancer is increasing. Oral, esophageal, and gastric cancers are considered as important causes of death. PIWI proteins and piRNAs are suggested to be involved in the pathogenesis of these diseases. Thus, studying these molecules may be beneficial for finding new therapeutics. Since it is shown that currently used biomarkers for these cancers have low sensitivity and specificity, there is a necessity for identifying novel non-invasive biomarkers which are highly sensitive and specific. This paper will provide an insight into current knowledge about the functions of PIWI proteins and piRNAs in the oral, esophageal, and gastric cancer. We discuss how PIWI proteins and piRNAs can be involved in the pathogenesis of these cancers. Moreover, we review the studies concerning with the roles of PIWI proteins and piRNAs as biomarkers which are used for diagnostic and prognostic purposes.

The MiR-17-92 Gene Cluster is a Blood-Based Marker for Cancer Detection in Non-Small-Cell Lung Cancer

Background

Lung cancer is one of the most malignant cancers threatening human health. The miR-17-92 gene cluster is a highly conserved oncogene cluster encoding 6 miRNAs: miR-17, miR-18a, miR-19a, miR-19b-1, miR-20a and miR-92a. This study explored whether these miRNAs can be used as diagnostic markers for non-small-cell lung cancer (NSCLC).

Methods

Serum samples were collected from healthy subjects (n = 23) and NSCLC patients at various stages (n = 74). Serum RNA was extracted by the TRIzol-glycogen method, and cDNA libraries were constructed by reverse transcription. Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to detect the expression levels of the 6 miRNAs.

Results

The expression levels of the 6 miRNAs varied in different stages of NSCLC. Thus, 2 receiver operating characteristic (ROC) curves, that is, normal subjects and stage I-III patients and normal subjects and stage IV patients, of each miRNA were established to determine the interval of normal ΔCt values. The 2 areas under the curve (AUCs) of each miRNA were investigated (miR-17: 0.8097 and 1.000; miR-18a: 0.7388 and 0.9907; miR-19a/19b: 0.8451 and 0.5104; miR-20a: 0.8975 and 1.000; miR-92a: 0.8097 and 0.8342). In addition, a high positive correlation was discovered between miR-17 and miR-20a expression. Combining these 2 miRNAs can improve the screening effect of NSCLC.

Conclusion

The miR-17-92 gene cluster can likely serve as a diagnostic marker in NSCLC.

Circulating microRNA expression profiling revealed miR-92a-3p as a novel biomarker of Barrett's carcinogenesis

The main intent of secondary prevention strategies for Barrett's esophagus (BE) patients relies in the prompt identification of patients with dysplasia (or intra-epithelial neoplasia; IEN) and early-stage adenocarcinoma (Barrett's adenocarcinoma; BAc). Despite the adequate characterization of the molecular landscape characterizing Barrett's carcinogenesis, no tissue and/or circulating biomarker has been approved for clinical use. A series of 25 serum samples (12 BE, 5 HG-IEN and 8 BAc) were analyzed for comprehensive miRNA profiling and ten miRNAs were found to be significantly dysregulated. In particular seven were upregulated (i.e. miR-92a-3p, miR-151a-5p, miR-362-3p, miR-345-3p, miR-619-3p, miR-1260b, and miR-1276) and three downregulated (i.e. miR-381-3p, miR-502-3p, and miR-3615) in HG-IEN/BAc samples in comparison to non-dysplastic BE. All the identified miRNAs showed significant ROC curves in discriminating among groups with AUC values range of 0.75-0.83. Validation of the results were performed by droplet digital PCR in two out of three tested miRNAs. To understand the cellular source of circulating miR-92a-3p, we analyzed its expression in endoscopy biopsy samples by both qRT-PCR and ISH analyses. As observed in serum samples, miR-92a-3p was over-expressed in HG-IEN/BAc samples in comparison to naïve esophageal squamous mucosa and BE and was mainly localized within the epithelial cells, supporting neoplastic cells as the main source of the circulating miRNA. Our data further demonstrated that circulating miRNAs are a promising mini-invasive diagnostic tool in the secondary follow-up and management of BE patients. Larger multi-Institutional studies should validate and investigate the most adequate miRNAs profile in discriminating BE patients in specific risk classes.

Serum Expression of Seven MicroRNAs in Chronic Lymphocytic Leukemia Patients

PURPOSE

MicroRNAs are small single-strand noncoding RNAs that can be deregulated in a variety of cancers. Over the past few years, multiple markers have been discovered in chronic lymphocytic leukemia (CLL). Among these, miRNAs seem to have important roles in the pathogenesis of CLL. The development and validation of miRNA-expression patterns as biomarkers should have a significant impact in cancer diagnosis, therapeutic success, and increasing the life expectancy of patients. In this study, to specify the utility of circulatory miRNA expression as noninvasive and useful biomarkers for CLL, we analyzed the dysregulation of seven miRNAs: miR30d, miR25-3p, miR19a-3p, miR133b, miR451a, miR145, and miR144 in CLL-patient sera.

METHODS

Thirty untreated patients with flow-cytometry confirmation of CLL were chosen. Serum samples were collected from 30 newly diagnosed CLL patients. Fifteen healthy samples were taken for comparison as controls. RNA was extracted using Trizol. RNA from CLL patient specimens was compared to controls with real-time PCR.

RESULTS

Seven miRNAs were differently expressed between CLL and normal specimens using the comparative 2-ΔΔCt method. miRNAs 133b, 25-3p, 451a, 145, 19a-3p, and 144 were overexpressed in sera obtained from CLL patients, and miRNA-30d was underexpressed in patient samples. Among these seven miRNAs, miR19a-3p and miR25-3p showed the most deregulation in CLL patients.

CONCLUSION

Real-time PCR is an applied means to perform high-throughput investigation of serum-RNA samples. We assessed the expression of seven miRNAs in CLL patients by this method. The results demonstrated that the use of miRNA-expression profiling may have an impressive role in the diagnosis of CLL. In addition, miRNA 19a-3p and 25-3p are known oncogenes with therapeutic and potential biomarkers.

DKK1 is epigenetically downregulated by promoter methylation and inhibits bile acid-induced gastric intestinal metaplasia

Dickkopf-related protein 1 (DKK1) is essential to gastric cancer as an inhibitor of Wnt signaling. Gastric intestinal metaplasia (GIM) is an important precancerous lesion of gastric cancer that can be activated by bile acid reflux and chronic inflammation. However, the exact mechanism of DKK1 in bile acid-induced GIM has not been completely elucidated. We aimed to explore the epigenetic alterations and biological functions of DKK1 in the development of GIM. In the present study, bile acid was found to induce the expression of intestinal markers in gastric epithelial cells, whereas DKK1 was downregulated in response to bile acid stimulation. The mRNA and protein expression levels of DKK1 were decreased in GIM tissues as evidenced by qRT-PCR and immunohistochemical staining. Surprisingly, the methylation of the DKK1 promoter increased in GIM tissues, and we discovered 28 differential methylation sites of the DKK1 promoter in GIM tissues. Bile acid was able to induce the partial methylation of the DKK1 promoter, while 5-aza could increase DKK1 expression as well as decrease intestinal markers expression in gastric epithelial cells. In conclusion, the promoter methylation and downregulation of DKK1 might play important roles in the development of GIM, especially bile acid-induced GIM.

Two-stage Bayesian GWAS of 9576 individuals identifies SNP regions that are targeted by miRNAs inversely expressed in Alzheimer's and cancer

INTRODUCTION

We compared genetic variants between Alzheimer's disease (AD) and two age-related cancers-breast and prostate -to identify single-nucleotide polymorphisms (SNPs) that are associated with inverse comorbidity of AD and cancer.

METHODS

Bayesian multinomial regression was used to compare sex-stratified cases (AD and cancer) against controls in a two-stage study. A ±500 KB region around each replicated hit was imputed and analyzed after merging individuals from the two stages. The microRNAs (miRNAs) that target the genes involving these SNPs were analyzed for miRNA family enrichment.

RESULTS

We identified 137 variants with inverse odds ratios for AD and cancer located on chromosomes 19, 4, and 5. The mapped miRNAs within the network were enriched for miR-17 and miR-515 families.

DISCUSSION

The identified SNPs were rs4298154 (intergenic), within TOMM40/APOE/APOC1, MARK4, CLPTM1, and near the VDAC1/FSTL4 locus. The miRNAs identified in our network have been previously reported to have inverse expression in AD and cancer.

MicroRNA-92a-1-5p increases CDX2 by targeting FOXD1 in bile acids-induced gastric intestinal metaplasia

BACKGROUND AND AIMS

Gastric intestinal metaplasia (IM) is common in the gastric epithelium of patients with chronic atrophic gastritis. CDX2 activation in IM is driven by reflux of bile acids and following chronic inflammation. But the mechanism underlying how bile acids activate CDX2 in gastric epithelium has not been fully explored.

METHODS

We performed microRNA (miRNA) and messenger RNA (mRNA) profiling using microarray in cells treated with bile acids. Data integration of the miRNA/mRNA profiles with gene ontology (GO) analysis and bioinformatics was performed to detect potential miRNA-mRNA regulatory circuits. Transfection of gastric cancer cell lines with miRNA mimics and inhibitors was used to evaluate their effects on the expression of candidate targets and functions. Immunohistochemistry and in situhybridisation were used to detect the expression of selected miRNAs and their targets in IM tissue microarrays.

RESULTS

We demonstrate a bile acids-triggered pathway involving upregulation of miR-92a-1-5p and suppression of its target FOXD1 in gastric cells. We first found that miR-92a-1-5p was increased in IM tissues and induced by bile acids. Moreover, miR-92a-1-5p was found to activate CDX2 and downstream intestinal markers by targeting FOXD1/FOXJ1 axis and modulating activation of nuclear factor kappa B (NF-κB) pathway. Furthermore, these effects were found to be clinical relevant, as high miR-92a-1-5p levels were correlated with low FOXD1 levels and high CDX2 levels in IM tissues.

CONCLUSION

These findings suggest a miR-92a-1-5p/FOXD1/NF-κB/CDX2 regulatory axis plays key roles in the generation of IM phenotype from gastric cells. Suppression of miR-92a-1-5p and restoration of FOXD1 may be a preventive approach for gastric IM in patients with bile regurgitation.

Cluster miRNAs and cancer: Diagnostic, prognostic and therapeutic opportunities

MiRNAs are class of noncoding RNA important for gene expression regulation in many plants, animals and viruses. MiRNA clusters contain a set of two or more miRNA encoding genes, transcribed together as polycistronic miRNAs. Currently, there are approximately 159 miRNA clusters reported in the human genome consisting of miRNAs ranging from two or more miRNA genes. A large proportion of clustered miRNAs resides in and around the fragile sites or cancer associated genomic hotspots and plays an important role in carcinogenesis. Altered expression of miRNA cluster can be pro-tumorigenic or anti-tumorigenic and can be targeted for clinical management of cancer. Over the past few years, manipulation of miRNA clusters expression is attempted for experimental purpose as well as for diagnostic, prognostic and therapeutic applications in cancer. Re-expression of miRNAs by epigenetic therapy, genome editing such as clustered regulatory interspaced short palindromic repeats (CRISPR) and miRNA mowers showed promising results in cancer therapy. In this review, we focused on the potential of miRNA clusters as a biomarker for diagnosis, prognosis, targeted therapy as well as strategies for modulating their expression in a therapeutic context. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Processing > Processing of Small RNAs RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs.

MicroRNA-19a-3p promotes rheumatoid arthritis fibroblast-like synoviocytes via targeting SOCS3

Rheumatoid arthritis (RA) is a common chronic autoimmune disease and effective treatment for RA is still lacking. In this study, the regulatory role of miR-19a-3p in RA was investigated. Quantitative polymerase chain reaction analysis of human blood samples showed that the level of miR-19a-3p was significantly lower in the RA patients compared with that in healthy patients (P < 0.05). In RA fibroblast-like synoviocytes (RAFLS), miR-19a-3p and suppressor of cytokine signaling 3 (SOCS3) were also downregulated and upregulated, respectively, compared with those of normal FLS. Transfection of miR-19a-3p mimic in RAFLS inhibited cell proliferation and promoted cell apoptosis. TargetScan identified SOCS3 as a target of miR-19a-3p, which was confirmed by dual-luciferase assay. Western blot indicated that SOCS3 protein level was significantly decreased after miR-19a-3p overexpression. Moreover, SOCS3 silencing through siRNA transfection also enhanced cell proliferation, meanwhile inhibiting RAFLS apoptosis. In addition, SOCS3 overexpression abrogated the effects of miR-19a-3p overexpression on cell proliferation and apoptosis, corroborating that SOCS3 acts as a downstream effector in the miR-19a-3p-mediated function of RAFLS. These findings suggest that miR-19a-3p plays an important role in RA, and the miR-19a-3p/SOCS3 axis may become a potential therapeutic target for RA.

Mir-421 in plasma as a potential diagnostic biomarker for precancerous gastric lesions and early gastric cancer

Objective

MicroRNA (miR)-421 plays a key role in cancer progression. It has been reported that circulating miR-421may be a potential tumor marker for the diagnosis of several cancers. However, the role of miR-421 in plasma as a potential biomarker in the diagnosis of precancerous gastric lesions (Pre) and early-stage gastric cancer (GC) remains poorly understood. In this study, we investigated miR-421 in plasma as a novel potential biomarker for the detection of precancerous gastric lesions and early-stage (GC).

Materials & Methods

The miRNA content was determined by quantitative real-time polymerase chain reaction (qRT-PCR). MiR-421 content in all subjects was normalized by endogenous miRNA (miR-16). The diagnostic value of miR-421 for Pre and GC was assessed by comparing receiver operating characteristic (ROC) analysis with traditional tumor markers, including CEA, CA125, CA153, CA211 and CA50. The correlation between the expression of miR-421 and the pathological characteristics of Pre and GC was analyzed.

Results

Elevated expression of miR-421 in plasma can robustly distinguish the normal population from Pre and GC cases, especially in the early stages of gastric cancer cases (all p < 0.05). The ROC analyses showed that the area under the ROC curve (AUC), sensitivity, accuracy and Youden index of miR-421 were superior to traditional tumor markers (CEA, CA125, CA153, CA211, and CA50) in GC diagnosis, while its specificity was higher than CEA, CA153 and CA50 (all p < 0.05). MiR-421 in plasma had higher AUC value than AFP, CA153, CA211 and CA50 in the diagnosis of Pre (all p < 0.05), while specificity, accuracy and Youden index of miR-421 was only lower than CA211. The efficiency of miR-421 in the diagnosis of GC was significantly higher than that of CA211 and CA50, and it was significantly higher than CA153, CA211 and CA50 in the diagnosis of Pre (all p < 0.05). In addition, up-regulation of miR-421 occurred initially in precancerous gastric lesions as well as in the early stage of GC.

Conclusions

Overexpression of plasma miR-421 is a novel biomarker for the detection of precancerous lesions and early gastric cancer.

Enhanced Inhibition of Tumorigenesis Using Combinations of miRNA-Targeted Therapeutics

The search for effective strategies to inhibit tumorigenesis remains one of the most relevant scientific challenges. Among the most promising approaches is the direct modulation of the function of short non-coding RNAs, particularly miRNAs. These molecules are propitious targets for anticancer therapy, since they perform key regulatory roles in a variety of signaling cascades related to cell proliferation, apoptosis, migration, and invasion. The development of pathological states is often associated with deregulation of miRNA expression. The present review describes in detail the strategies aimed at modulating miRNA activity that invoke antisense oligonucleotide construction, such as small RNA zippers, miRNases (miRNA-targeted artificial ribonucleases), miRNA sponges, miRNA masks, anti-miRNA oligonucleotides, and synthetic miRNA mimics. The broad impact of developed miRNA-based therapeutics on the various events of tumorigenesis is also discussed. Above all, the focus of this review is to evaluate the results of the combined application of different miRNA-based agents and chemotherapeutic drugs for the inhibition of tumor development. Many studies indicate a considerable increase in the efficacy of anticancer therapy as a result of additive or synergistic effects of simultaneously applied therapies. Different drug combinations, such as a cocktail of antisense oligonucleotides or multipotent miRNA sponges directed at several oncogenic microRNAs belonging to the same/different miRNA families, a mixture of anti-miRNA oligonucleotides and cytostatic drugs, and a combination of synthetic miRNA mimics, have a more complex and profound effect on the various events of tumorigenesis as compared with treatment with a single miRNA-based agent or chemotherapeutic drug. These data provide strong evidence that the simultaneous application of several distinct strategies aimed at suppressing different cellular processes linked to tumorigenesis is a promising approach for cancer therapy.

Serum exosomal miR-210 as a potential biomarker for clear cell renal cell carcinoma

Exosomal microRNAs (miRNAs) are suggested to reflect molecular changes occurring in their cells of origin and are potential indicators in the early detection of cancers. This study aimed to determine whether certain exosomal miRNAs from tumor tissue can be used as noninvasive biomarkers for clear cell renal cell carcinoma (ccRCC). Based on ccRCC miRNA expression profiles and the literature, we selected six miRNAs (miR-210, miR-224, miR-452, miR-155, miR-21, and miR-34a) and analyzed their expression in tissues, sera, and serum exosomes through quantitative real-time polymerase chain reaction in hypoxia-induced (with CoCl₂ ) renal cell lines. miR-210, miR-224, miR-452, miR-155, and miR-21 were upregulated in tumor tissues compared with normal tissues. Serum miR-210 and miR-155 levels were higher in patients with ccRCC than in healthy controls (HCs). Furthermore, only exosomal miR-210 was significantly upregulated in patients with ccRCC than in HCs. Moreover, receiver operating characteristic (ROC) curve analysis revealed an area under the ROC curve of 0.8779 (95% confidence interval, 0.7987-0.9571) and a sensitivity and specificity of 82.5% and 80.0%, respectively. Moreover, exosomal miR-210 was upregulated at an advanced stage, and Fuhrman grade and metastasis decreased significantly one month after surgery. Acute hypoxia exposure activates miR-210 and release of exosomes with upregulated miR-210 in both normal and tumor RCC cell lines and interferes with vacuole membrane protein 1 mRNA expression, especially in the metastatic ccRCC cell line. In conclusion, Serum exosomal miR-210 originating from tumor tissue has potential as a novel noninvasive biomarker for the detection and prognosis of ccRCC.

The diagnostic value of circulating microRNAs as a biomarker for gastric cancer: A meta‑analysis

Recently, cancer research microRNA studies have drawn great attention. However, the results of these studies have been inconsistent and variable regarding the availability of circulating miRNAs in gastric cancer (GC) diagnosis. Thus, results should be interpreted cautiously. The purpose of the present study was to assess the diagnostic performance of circulating miRNAs in GC diagnosis. We conducted a systematic and comprehensive approach for the inclusion of studies. The sensitivity, specificity, and diagnostic odds ratio were pooled with random effects models, and a summary of receiver operator characteristic (SROC) curves were plotted. The potential heterogeneity was assessed with Q test and I2 statistics. Subgroup analyses and meta‑regressions further investigated the sources of heterogeneity. A total of 77 studies from 48 articles were eligible for the meta‑analysis. The results revealed a sensitivity of 0.76, a specificity of 0.81, and an AUC of 0.86 for gastric cancer diagnosis with circulating miRNAs. In addition, subgroup analyses indicated that multiple miRNAs assays, non‑microarray screening approaches, and serum‑based miRNA assays exhibited good diagnostic performance in contrast to a single miRNA assay, microarray expression profiling screening, and plasma‑based miRNA group analysis. The diagnostic ability of miRNAs in early stage I‑II groups and the high expression group were approximately similar to that in the stage I‑IV groups and the low expression group. For the circulating miRNAs, our meta‑analysis identified a combination of multiple miRNAs, non‑microarray chip screening, and serum‑based miRNA assays were associated with the most effective GC diagnostic performance. However, many unclear molecular mechanisms limited the accuracy of the diagnostic results, and should be interpreted with caution. Further large‑scale prospective studies are required for validating the diagnostic applicability of circulating miRNAs in gastric cancer patients.

MicroRNA-17 promotes osteosarcoma cells proliferation and migration and inhibits apoptosis by regulating SASH1 expression

MicroRNAs (miRNAs) are abnormally expressed in numerous diseases, which are intimately associated with cell proliferation, migration and invasion. Recent study indicated that miR-17 may be involved in regulating osteosarcoma (OS) occurrence and development, but its function and mechanism have not been reported. In this study, quantitative real-time PCR (qRT-PCR) was used to measure the expression of miR-17, and Western blotting assay was performed to measure the expressions of SAM and SH3 domain containing 1 (SASH1), phosphoinoinositide-3 kinase (PI3K), protein kinase B (AKT), Caspase3, Bcl-2 gene family (Bcl-2, Bax) and matrix metalloprotein (MMP-2, MMP-9) in MG-63 cells. Luciferase reporter assay was conducted to confirm the target of SASH1 by miR-17. Cell proliferation, migration, invasion and apoptosis assay was performed to investigate the role of miR-17 in OS cells. We found that the expression of miR-17 was significantly up-regulated in OS cell lines. MiR-17 inhibitor inhibited the proliferation ability, and induced apoptosis of OS cells. Besides, miR-17 inhibitor prevented the migration and invasion of OS cells. Further, we identified that SASH1 was a target gene of miR-17. In addition, knockdown of miR-17 increased the protein expression of SASH1, and regulate related genes of cell proliferation, invasion and anti-apoptosis in the downstream of OS cells. These findings indicated that miR-17 was over-expressed and promoted cell proliferation, migration and inhibited cell apoptosis by targeting SASH1 in OS cells.

miR-17-92 functions as an oncogene and modulates NF-κB signaling by targeting TRAF3 in MGC-803 human gastric cancer cells

The miR-17-92 cluster plays either an oncogenic or anti-oncogenic role in cancer progression in diverse human cancers. However, the underlying mechanisms of the miR-17-92 cluster in gastric cancer have not yet been fully elucidated. In this study, the function of the miR-17-92 cluster in diverse aspects of MGC-803 gastric cancer cells was systematically elucidated. The enforced introduction of the miR-17-92 cluster into the MGC-803 cells significantly promoted cell growth due to the increased cellular proliferation and decreased cellular apoptosis, which were detected by CCK-8, cell viability and TUNEL assays. Moreover, the results of western blot analyses revealed that the activated protein kinase B (AKT), extracellular-signal-regulated kinase (ERK) and nuclear factor (NF-κB) signaling pathways were activated in these processes. Moreover, the overexpression of the miR-17-92 cluster markedly enhanced the migratory and invasive abilities of the MGC-803 cells, which was associated with the occurrence of epithelial-mesenchymal transition (EMT). Tumor necrosis factor receptor associated factor 3 (TRAF3), which negatively regulates the NF-κB signaling pathway, was identified as a direct target of miR-17-92. Furthermore, TRAF3 silencing enhanced the oncogenic functions of the miR-17-92 cluster in the MGC-803 cells, including the increased cellular proliferation, migration and invasion. Moreover, immunohistochemical staining and survival analyses of a gastric cancer tissue microarray revealed that TRAF3 functioned as a tumor suppressor in gastric cancer. Taken together, the findings of this study provide new insight into the specific biological functions of the miR-17-92 cluster in gastric cancer progression by directly targeting TRAF3.

miR-17-92 cluster is connected with disease progression and oxaliplatin/capecitabine chemotherapy efficacy in advanced gastric cancer patients: A preliminary study

This study aimed to determine the role of plasma miR-17-92 cluster level in predicting chemoresistance in patients with gastric cancer (GC) undergoing oxaliplatin/capecitabine (XELOX) chemotherapy.Patients recently diagnosed with advanced GC were chosen as participants based on the inclusion criteria. The plasma levels of miR-17-5p, miR-18a, miR-19a/b, miR-20a, and miR-92-1 (miR-17-92 cluster) were determined through quantitative RT-PCR of blood samples from GC patients and healthy volunteers. All the patients received XELOX chemotherapy, and the effectiveness of the chemotherapy was evaluated.The miR-17-92 plasma level was increased in advanced GC patients and decreased after XELOX chemotherapy. Moreover, the miR-17-92 cluster level was associated with chemotherapy response but not with chemotherapy-related toxicity. The miR-17-92 cluster plasma level was decreased in chemosensitive patients, but not in chemoresistant patients, after chemotherapy. The sensitivity and specificity of the combined detection of the miR-17-92 cluster in patients with advanced GC were 100% each.The results suggest that the miR-17-92 plasma level is associated with the progression of advanced GC and effectiveness of XELOX chemotherapy.

The correlation of circulating pro-angiogenic miRNAs' expressions with disease risk, clinicopathological features, and survival profiles in gastric cancer

This study aimed to explore the correlation of circulating pro‐angiogenic miRNAs’ expressions with risk, clinicopathological features, and survival profiles in gastric cancer (GC). Three hundred and thirty‐three GC patients underwent radical resection and 117 health controls (HCs) were recruited for this study. Plasma samples were obtained from GC patients before the operation and from HCs after enrollment. Fourteen pro‐angiogenic miRNAs were asseassed by quantitative polymerase chain reaction (qPCR). Disease‐free survival (DFS) and overall survival (OS) of GC patients were calculated and the median follow‐up duration was 36.0 months. Seven out of 14 pro‐angiogenic miRNAs including let‐7f, miR‐17‐5p, miR‐18a, miR‐19b‐1, miR‐20a, miR‐210, and miR‐296 were observed to be elevated in GC patients compared with HCs. MiR‐18a, miR‐20a, and miR‐210 disclosed good predictive values of GC risk. Six pro‐angiogenic miRNAs including miR‐17‐5p, miR‐92a, miR‐210, miR‐20a, miR‐18a, and miR‐296 expressions were positively while 1 pro‐angiogenic miRNA (miR‐130a) was negatively correlated with tumor malignancy degree in GC patients. K‐M curve disclosed that 5 pro‐angiogenic miRNAs including miR‐17‐5p, miR‐18a, miR‐20a, miR‐92a, and miR‐210 correlated with worse DFS, while 4 pro‐angiogenic miRNAs including miR‐17‐5p, miR‐18a, miR‐20a, and miR‐210 associated with shorter OS. Further multivariate Cox's analysis revealed that miR‐17‐5p, miR‐18a, miR‐20a, and miR‐210 were independent predictive factors for unfavorable DFS and OS. In conclusion, circulating pro‐angiogenic miRNAs could serve as novel noninvasive biomarkers for disease risk and malignancy degree, and miR‐17‐5p, miR‐18a, miR‐20a, and miR‐210 are independent factors predicting poor prognosis in GC patients.

The expression of Mirc1/Mir17-92 cluster in sputum samples correlates with pulmonary exacerbations in cystic fibrosis patients

INTRODUCTION

Cystic fibrosis (CF) is a multi-organ disorder characterized by chronic sino-pulmonary infections and inflammation. Many patients with CF suffer from repeated pulmonary exacerbations that are predictors of worsened long-term morbidity and mortality. There are no reliable markers that associate with the onset or progression of an exacerbation or pulmonary deterioration. Previously, we found that the Mirc1/Mir17-92a cluster which is comprised of 6 microRNAs (Mirs) is highly expressed in CF mice and negatively regulates autophagy which in turn improves CF transmembrane conductance regulator (CFTR) function. Therefore, here we sought to examine the expression of individual Mirs within the Mirc1/Mir17-92 cluster in human cells and biological fluids and determine their role as biomarkers of pulmonary exacerbations and response to treatment.

METHODS

Mirc1/Mir17-92 cluster expression was measured in human CF and non-CF plasma, blood-derived neutrophils, and sputum samples. Values were correlated with pulmonary function, exacerbations and use of CFTR modulators.

RESULTS

Mirc1/Mir17-92 cluster expression was not significantly elevated in CF neutrophils nor plasma when compared to the non-CF cohort. Cluster expression in CF sputum was significantly higher than its expression in plasma. Elevated CF sputum Mirc1/Mir17-92 cluster expression positively correlated with pulmonary exacerbations and negatively correlated with lung function. Patients with CF undergoing treatment with the CFTR modulator Ivacaftor/Lumacaftor did not demonstrate significant change in the expression Mirc1/Mir17-92 cluster after six months of treatment.

CONCLUSIONS

Mirc1/Mir17-92 cluster expression is a promising biomarker of respiratory status in patients with CF including pulmonary exacerbation.

High circulating miR-18a, miR-20a, and miR-92a expression correlates with poor prognosis in patients with non-small cell lung cancer

The purpose of this study was to assess the predictive value of angiogenic miRNAs for disease-free survival (DFS) and overall survival (OS) of patients with non-small cell lung cancer (NSCLC). In total, 196 patients with NSCLC (tumor lymph nodes metastasis (TNM) stage I-III) were enrolled and peripheral blood samples were collected. Total RNA was extracted from blood samples, and the relative expression levels of candidate miRNAs were evaluated by real time-polymerase chain reaction (RT-PCR). The median follow-up period was 56.7 months, and the final follow-up date was in August 2016. The median DFS of all patients was 30.0 (14.0-49.0) months, whereas the median OS was 41.5 (23.0-58.0) months. Furthermore, the 5-year DFS and OS rates were 11.3% and 32.3%, respectively. Kaplan-Meier (K-M) curves showed that high plasma miR-18a (P < 0.001), miR-20a (P < 0.001), miR-92a (P < 0.001), miR-126 (P < 0.001), miR-210 (P = 0.003), and miR-19a (P = 0.027) expressions levels correlated with a worse DFS. Moreover, patients with high plasma miR-18a, miR-20a, miR-92a, miR-210, and miR-126 expression levels had a shorter OS than patients with low expression levels of these miRNAs (all P <= 0.001). Furthermore, multivariate Cox regression analyses revealed that high plasma expression levels of miR-18a, miR-20a, and miR-92a as well as lymphatic node metastasis (all P < 0.001) were independent risk factors for both DFS and OS in patients with NSCLC. Thus, the circulating miR-18a, miR-20a, and miR-92a levels may serve as novel and promising prognostic biomarkers in patients with NSCLC.

Increased miR-25 expression in serum of gastric cancer patients is correlated with CA19-9 and acts as a potential diagnostic biomarker

Objective

To evaluate miR-25 expression in serum of gastric cancer (GC) patients and whether it can be a potential biomarker for GC diagnosis.

Methods

Forty one pathology confirmed GC patients and 41 healthy controls were included in this study. 10 mL peripheral venous blood were collected from GC patients and healthy controls. miR-25 relative expression and CA19-9 level in serum of GC patients and healthy controls were measured by real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR) and enzyme linked immunosorbent assay (ELISA), respectively. The diagnostic sensitivity, specificity and receiver operating characteristic (ROC) curve of serum miR-25 and CA19-9 were calculated by STATA11.0 software.

Results

The relative expression of miR-25 was 0.47±0.53 and 0.05±0.36 in serum of GC patients and healthy controls respectively with significant statistical difference (P<0.05). The serum level of CA19-9 for GC patients and healthy controls were 11.91±6.17 U/mL and 7.40±3.97 U/mL, indicating GC patients were much higher than those of healthy controls (P<0.05). The diagnostic sensitivity and specificity were 78.05% and 60.98% with the cut-off value of 0.32 for serum miR-25. Under this cut-off value, the area under the ROC curve was 0.75. For serum CA19-9, the diagnostic sensitivity and specificity were 70.73% and 56.10% with the cut-off value of 9.22 U/mL. Under this cut-off value, the area under the ROC curve was 0.73 with the 95% confidence interval of 0.62-0.84. Positive correlation was found between serum miR-25 relative expression and CA19-9 concentration of GC patients (r=0.75, P<0.05).

Conclusion

According to our present study, serum miR-25 was elevated in GC patients which may serve as a diagnostic biomarker for GC.