Downregulation of hsa-microRNA-204-5p and identification of its potential regulatory network in non-small cell lung cancer: RT-qPCR, bioinformatic- and meta-analyses.

BACKGROUND: Pulmonary malignant neoplasms have a high worldwide morbidity and mortality, so the study of these malignancies using microRNAs (miRNAs) has attracted great interest and enthusiasm. The aim of this study was to determine the clinical effect of hsa-microRNA-204-5p (miR-204-5p) and its underlying molecular mechanisms in non-small cell lung cancer (NSCLC). METHODS: Expression of miR-204-5p was investigated by real-time quantitative PCR (RT-qPCR). After data mining from public online repositories, several integrative assessment methods, including receiver operating characteristic (ROC) curves, hazard ratios (HR) with 95% confidence intervals (95% CI), and comprehensive meta-analyses, were conducted to explore the expression and clinical utility of miR-204-5p. The potential objects regulated and controlled by miR-204-5p in the course of NSCLC were identified by estimated target prediction and analysis. The regulatory network of miR-204-5p, with its target genes and transcription factors (TFs), was structured from database evidence and literature references. RESULTS: The expression of miR-204-5p was downregulated in NSCLC, and the downtrend was related to gender, histological type, vascular invasion, tumor size, clinicopathologic grade and lymph node metastasis (P<0.05). MiR-204-5p was useful in prognosis, but was deemed unsuitable at present as an auxiliary diagnostic or prognostic risk factor for NSCLC due to the lack of statistical significance in meta-analyses and absence of large-scale investigations. Gene enrichment and annotation analyses identified miR-204-5p candidate targets that took part in various genetic activities and biological functions. The predicted TFs, like MAX, MYC, and RUNX1, interfered in regulatory networks involving miR-204-5p and its predicted hub genes, though a modulatory loop or axis of the miRNA-TF-gene that was out of range with shortage in database prediction, experimental proof and literature confirmation. CONCLUSIONS: The frequently observed decrease in miR-204-5p was helpful for NSCLC diagnosis. The estimated target genes and TFs contributed to the anti-oncogene effects of miR-204-5p.

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

BACKGROUND/AIMS: Studies have shown that miR-146a-5p was differentially expressed in diverse cancers, but the associations between miR-146a-5p expression and prognosis across multiple types of cancer as well its potential targets and downstream pathways have not been comprehensively analyzed. In this study, we performed the first meta-analysis of the prognostic value of miR-146a-5p expression in diverse malignancies and explored prospective targets of miR-146a-5p and related signaling pathways. METHODS: A thorough search for articles related to miR-146a-5p was performed, and RNA-seq data from The Cancer Genome Atlas (TCGA) and microarray data from gene expression omnibus profiles were used to collect information about the prognostic value of miR-146a-5p. A comprehensive meta-analysis was conducted. Twelve platforms in miRWalk 2.0 were applied to predict targets of miR-146a-5p. TCGA RNA-seq data were used to validate the inverse relationships between miR-146a-5p and its likely targets. Subsequently, gene ontology and pathway analyses were conducted using Funrich version 3.1.3. Potential protein-protein interaction (PPI) networks were constructed. Potential target genes of miR-146a-5p in lung cancer were validated by RT-qPCR. RESULTS: We included 10 articles in the meta-analysis. In a pooled analysis, the high miR-146a-5p expression group showed a better overall survival in solid cancers, particularly in reproductive system cancers and digestive system cancers. A total of 120 predicted target genes were included in a bioinformatics analysis. Five pathways involving phospholipase C (PLC) and aquaporins (AQPs) were the most significantly enriched Kyoto Encyclopedia of Genes and Genomes pathways. Moreover, the PPI network displayed the related signaling pathways and interactions among proteins. AQP1 and FYN were validated by RT-qPCR to be potential targets of miR-146a-5p in lung cancer. CONCLUSION: There is a close link between high miR-146a-5p expression and better overall survival in 21 types of solid cancer, especially in reproductive system and digestive system cancers. Furthermore, miR-146a-5p could inhibit diverse malignancies by modulating pathways linked to PLC or AQPs. In summary, miR-146a-5p is a potential prognostic biomarker and therapeutic target for various cancers.

Down-regulation of microRNA-144-3p and its clinical value in non-small cell lung cancer: a comprehensive analysis based on microarray, miRNA-sequencing, and quantitative real-time PCR data.

BACKGROUND: Previous studies have shown that miR-144-3p might be a potential biomarker in non-small cell lung cancer (NSCLC). Nevertheless, the comprehensive mechanism behind the effects of miR-144-3p on the origin, differentiation, and apoptosis of NSCLC, as well as the relationship between miR-144-3p and clinical parameters, has been rarely reported. METHODS: We investigated the correlations between miR-144-3p expression and clinical characteristics through data collected from Gene Expression Omnibus (GEO) microarrays, the relevant literature, The Cancer Genome Atlas (TCGA), and real-time quantitative real-time PCR (RT-qPCR) analyses to determine the clinical role of miR-144-3p in NSCLC. Furthermore, we investigated the biological function of miR-144-3p by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Protein-protein interaction (PPI) network was created to identify the hub genes. RESULTS: From the comprehensive meta-analysis, the combined SMD of miR-144-3p was - 0.95 with 95% CI of (- 1.37, - 0.52), indicating that less miR-144-3p was expressed in the NSCLC tissue than in the normal tissue. MiR-144-3p expression was significantly correlated with stage, lymph node metastasis and vascular invasion (all P <  0.05). As for the bioinformatics analyses, a total of 37 genes were chosen as the potential targets of miR-144-3p in NSCLC. These promising target genes were highly enriched in various key pathways such as the protein digestion and absorption and the thyroid hormone signaling pathways. Additionally, PPI revealed five genes-C12orf5, CEP55, E2F8, STIL, and TOP2A-as hub genes with the threshold value of 6. CONCLUSIONS: The current study validated that miR-144-3p was lowly expressed in NSCLC. More importantly, miR-144-3p might function as a latent tumor biomarker in the prognosis prediction for NSCLC. The results of bioinformatics analyses may present a new method for investigating the pathogenesis of NSCLC.

The LncRNA NEAT1 Accelerates Lung Adenocarcinoma Deterioration and Binds to Mir-193a-3p as a Competitive Endogenous RNA.

BACKGROUND/AIMS: Long noncoding RNAs (lncRNAs) contribute to the development of multiple malignant tumors. Here, we focused on the biological function and underlying molecular mechanism of an lncRNA, nuclear-enriched abundant transcript 1 (NEAT1), in lung adenocarcinoma (LUAD). METHODS: In vitro experiments were conducted to determine the biological effects of NEAT1 in LUAD cells. A luciferase activity reporter assay was performed to corroborate the interaction between NEAT1 and miR-193a-3p. Data from Gene Expression Omnibus (GEO), Oncomine, The Cancer Genome Atlas (TCGA), and our in-house reverse transcription quantitative PCR (RT-qPCR) were combined to examine the expression of NEAT1 and miR-193a-3p in LUAD. To further explore the regulatory mechanism of NEAT1, we searched for putative target genes of miR-193a-3p from 12 online prediction databases and determined genes positively correlated with NEAT1 as candidate targets. Furthermore, we analyzed the expression of these selected genes using data from TCGA. RESULTS: In vitro experiments showed that knockdown of NEAT1 in LUAD cells markedly restrained cell proliferation, invasion, and migration and stimulated cell apoptosis. The dual-luciferase reporter assay demonstrated that miR-193a-3p directly targeted NEAT1 at its 3'-UTR. We then detected NEAT1 and miR-193a-3p in LUAD cells and normal lung epithelial cells and discovered high expression of NEAT1 and low expression of miR-193a-3p in LUAD cell lines. Simultaneously, the pooled results from the GEO, Oncomine, TCGA, and in-house RT-qPCR showed that the NEAT1 expression increased while the miR-193a-3p expression decreased in LUAD tissues versus normal lung tissues. Furthermore, the USF1 gene was not only upregulated in LUAD, but also positively correlated with NEAT1, suggesting that NEAT1 may function as a ceRNA to sponge miR-193a-3p and abrogate the inhibitory effect of miR-193a-3p on USF1. CONCLUSIONS: Our findings indicate that NEAT1 plays important roles in the occurrence and progression of LUAD. It may exert its role by acting as a ceRNA to regulate miR-193a-3p.

Expression Signature and Role of miR-30d-5p in Non-Small Cell Lung Cancer: a Comprehensive Study Based on in Silico Analysis of Public Databases and in Vitro Experiments.

BACKGROUND/AIMS: The purpose of this study was to probe the clinico-pathological significance and the underlying mechanism of miR-30d-5p expression in non-small cell lung cancer (NSCLC). METHODS: We initially examined the level of miR-30d-5p expression in NSCLC and non-cancer tissues using RT-qPCR. Then, a series of validation analyses including a meta-analysis of data from microarray chips in Gene Expression Omnibus (GEO), data mining of the cancer genome atlas (TCGA) and an integrated meta-analysis incorporating GEO microarray chips, TCGA data, in-house RT-qPCR and literature studies were performed to examine the clinico-pathological value of miR-30d-5p expression in NSCLC. In vitro experiments were further conducted to investigate the impact of miR-30d-5p on NSCLC cell growth. The molecular mechanism by which miR-30d-5p regulates the pathogenesis of NSCLC was probed through a bioinformatics analysis of its target genes. Moreover, dual luciferase reporter assay was conducted to verify the targeting regulatory relationship between miR-30d-5p and CCNE2. RESULTS: Based on results from RT-qPCR, GEO meta-analysis, TCGA data mining and the integrated meta-analysis incorporating GEO microarray chips, TCGA data, in-house RT-qPCR and literature studies, miR-30d-5p expression was decreased in NSCLC tissues, and patients with NSCLC who presented with lower miR-30d-5p expression tended to display an advanced clinical progression. Significant pathways including the Mucin type O-glycan biosynthesis pathway, cell cycle pathway and cysteine and methionine metabolism pathway (all P< 0.05) revealed potential roles of the target genes of miR-30d-5p in the oncogenesis of NSCLC. Results from in vitro experiments indicated that miR-30d-5p could attenuate proliferation and viability of NSCLC cells. Among the 12 identified hub genes, nine genes including E2F3, CCNE2, SKP2, CDK6, TFDP1, LDHA, GOT2, DNMT3B and ST6GALNAC1 were validated by Pearson's correlation test and the human protein atlas (HPA) database as targets of miR-30d-5p with higher probability. Specifically, dual luciferase reporter assay confirmed that CCNE2 was directly targeted by miR-30d-5p. CONCLUSION: In summary, miR-30d-5p expression is decreased in NSCLC, and it might play the role as tumor suppressor in NSCLC by regulating target genes.

Clinical value of miR-145-5p in NSCLC and potential molecular mechanism exploration: A retrospective study based on GEO, qRT-PCR, and TCGA data.

MicroRNAs have been reported to be involved in various biological processes. Here, we performed a systematic analysis to explore the clinical value and potential molecular mechanism of miR-145-5p in non-small cell lung cancer. First, a meta-analysis was performed with eligible literature, followed by microRNA microarrays in the Gene Expression Omnibus database, to verify the diagnostic and prognostic values of miR-145-5p. A cohort of 125 clinical paired non-small cell lung cancer samples was next used to detect the level of miR-145-5p and to explore the relationship of miR-145-5p with clinicopathological parameters. The Cancer Genome Atlas database was additionally applied to investigate the role of miR-145-5p in non-small cell lung cancer. The potential targets of miR-145-5p were predicted using 12 online prediction databases to explore the prospective molecular mechanism of miR-145-5p in non-small cell lung cancer. The expression of miR-145-5p in non-small cell lung cancer was significantly lower than that in healthy tissues. And miR-145-5p tended to show better diagnostic performance in lung squamous cell carcinoma than in lung adenocarcinoma. Furthermore, the expression of miR-145-5p was closely associated with lymph node metastasis in non-small cell lung cancer. Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the target genes were mainly enriched with enzyme-linked receptor protein signaling pathways, SH3 domain binding, cell leading edge, and adherens junction. The protein-protein interaction network showed that eight hub genes (SMAD4, SMAD2, IRS1, FOXO1, ERBB4, NRAS, ACTB, and ACTG1) might be the key target genes of miR-145-5p in non-small cell lung cancer. The information we obtained might offer new perspectives for clinical diagnosis and treatment for non-small cell lung cancer.

Clinical Value and Prospective Pathway Signaling of MicroRNA-375 in Lung Adenocarcinoma: A Study Based on the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and Bioinformatics Analysis.

BACKGROUND Lung adenocarcinoma (LUAD) is the most frequent lung cancer. MicroRNAs (miRNAs) are believed to have fundamental roles in tumorigenesis of LUAD. Although miRNAs are broadly recognized in LUAD, the role of microRNA-375 in LUAD is still not fully elucidated. MATERIAL AND METHODS We evaluated the significance of miR-375 expression in LUAD by using analysis of a public dataset from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database and a literature review. Furthermore, we investigated the biological function of miR-375 by gene ontology enrichment and target prediction analysis. RESULTS MiR-375 expression was significantly higher in LUAD by TCGA data compared to normal lung tissue (p<0.0001). In addition, a common pattern of upregulation for miR-375 in LUAD was found in our review of the literature. A total of 682 genes, both LUAD-related and miR-375-related, were obtained from the analytical integration. Critical pathways were unveiled in the network analysis of the overlaps, such as pentose and glucuronate interconversions, ascorbate and aldarate metabolism, and starch and sucrose metabolism. Furthermore, we identified covert miR-375 associated genes that might participate in LUAD by network analysis, such as FGF2 (fibroblast growth factor 2), PAX6 (paired box 6), and RHOJ. The expression of these three genes were all downregulated in LUAD. Finally, FGF2 was revealed to be negatively correlated with miR-375 in LUAD (r=-0.1821, p=0.0001). CONCLUSIONS Overall, our study provides evidence that miR-375 is essential for the progression of LUAD.

An immunohistochemical study of cyclin-dependent kinase 5 (CDK5) expression in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC): a possible prognostic biomarker.

BACKGROUND: Cyclin-dependent kinase 5 (CDK5) is an atypical CDK which plays a vital role in several cancers via regulating migration and motility of cancer cells. However, the clinicopathological impact and function of CDK5 in lung cancer remain poorly understood. The present study was aimed at exploring expression and clinicopathological significance of CDK5 in lung cancer. METHODS: There were 395 samples of lung tissue including 365 lung tumors (339 non-small cell lung cancers and 26 small cell lung cancers) and 30 samples of normal lung. CDK5 expression was detected by immunohistochemistry on lung tissue microarrays. RESULTS: Over expression was detected in lung cancer compared with normal lung tissues (P=0.001). Furthermore, area under curve (AUC) of receiver operating characteristic (ROC) of CDK5 was 0.685 (95% CI 0.564~0.751, P=0.004). In lung cancer, we also discovered close correlations between CDK5 and pathological grading (r=0.310, P<0.001), TNM stage (r=0.155, P=0.003), and lymph node metastasis (r=0.279, P<0.001) by using Spearman analysis. In two subgroups of non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), the expression of CDK5 was also higher than that of normal lung tissue, respectively (P=0.001 and P=0.004). Moreover, in NSCLCs, Spearman analysis revealed that expression of CDK5 was correlated with TNM stages (r=0.129, P=0.017), lymph node metastasis (r=0.365, P<0.001), and pathological grading (r=0.307, P<0.001), respectively. The significant correlation was also found between CDK5 expression and TNM stages (r=0.415, P=0.049) and lymphatic metastasis (r=0.469, P=0.024) in SCLCs. CONCLUSIONS: The results of this present study suggest that the CDK5 expression is associated with several clinicopathological factors linked with poorer prognosis.

Expression and clinical contribution of MRGD mRNA in non-small cell lung cancers.

PURPOSE: MAS-related G protein-coupled receptor, member D (MRGD) has been reported to be involved in tumorigenesis in vivo. However, the clinical role of MRGD in non-small cell lung cancer (NSCLC) remains unclarified. The purpose of the current study was to detect the expression of MRGD mRNA in NSCLC formalin-fixed (FF), paraffin-embedded (PE) tissues and to investigate the clinicopathological significance of the MRGD level in NSCLC patients. METHODS: The expression of MRGD mRNA was examined in 125 NSCLC tissue samples together with paired para-noncancerous FF/PE tissues by using real time quantitative PCR (qRT-PCR). Furthermore, the relationship between MRGD level and clinicopathological parameters of NSCLC was analyzed. RESULTS: The average level of MRGD in NSCLC tumor tissues (1.0682±0.6096) was remarkably higher than that in the adjacent non-cancerous lung tissue (0.3994±0.2838, p<0.001). The area under curve (AUC) of receiver operating characteristic curve (ROC) of MRGD mRNA was 0.853 (95% CI: 0.808-0.898, p(0.001). Moreover, the level of MRGD mRNA was found to be correlated to lymph node metastasis (r=0.219, p=0.014), tumor size (r=0.221, p=0.013) and clinical TNM stage (r=0.187, p=0.037). Finally, the survival of patients in high MGRD expression group was 7.94±9.85 months, remarkably shorter than that of the low expression group (20.84±1.19 months, p=0.049). CONCLUSIONS: MRGD may be a vital diagnostic and prognostic factor in NSCLC. MRGD possesses the potential to become a new target for the molecular therapy of NSCLC.

A comprehensive investigation regarding the clinical significance of ITGB4 in oral squamous cell carcinoma combining immunohistochemistry, RNA-seq, and microarray data.

OBJECTIVE: Integrin subunit beta 4 (ITGB4), a receptor for laminins, was an oncoprotein in several malignancies. However, its clinical role in oral squamous cell carcinoma (OSCC) remains unclear. MATERIALS AND METHODS: Firstly, 99 OSCC and 13 normal oral epithelium samples were employed for immunohistochemistry (IHC) for detecting the expression level of ITGB4 protein in OSCC. Subsequently, 971 OSCC and 281 non-cancerous specimens from RNA-seq and 18 microarrays were applied for investigating the expression of ITGB4 mRNA. Furthermore, to explore the potential mechanism of ITGB4 in OSCC, the co-expressed genes of ITGB4 were initially screened using all available datasets, and were further utilized for the gene enrichment analysis. RESULTS: First, IHC showed a distinctively higher expression level of the ITGB4 protein in the OSCC group than that in the normal controls. Second, expression profile from RNA-seq and microarrays reflected that ITGB4 mRNA was dramatically overexpressed in OSCC tissues compared with non-tumor tissues. Third, standardized mean difference (SMD) with the area under the summary receiver operating characteristic (sROC) curve combining all incorporated data revealed that ITGB4 was consistently significantly upregulated in OSCC tissues, with the SMD value being 1.31 and the area under the sROC curve being 0.82. Lastly, 184 upregulated and 179 downregulated co-expressed genes of ITGB4 were utilized for enrichment analysis, which demonstrated that ITGB4 might influence the pathogenesis of OSCC through cell cycle, ECM-receptor interaction and focal adhesion pathways. CONCLUSIONS: ITGB4 might play a pivotal role in the tumorigenesis and progression of OSCC, making it a promising biomarker of OSCC.

Correction: Clinical significance and effect of AEG-1 on the proliferation, invasion, and migration of NSCLC: a study based on immunohistochemistry, TCGA, bioinformatics, in vitro and in vivo verification.

[This corrects the article DOI: 10.18632/oncotarget.14972.].

Clinical Value and Potential Mechanism of miRNA-33a-5p in Lung Squamous Cell Carcinoma.

This study is aimed at thoroughly exploring the expression status, clinical significance, and underlying molecular mechanism of miRNA-33a-5p in lung squamous cell carcinoma (LUSC). Here, we detected miRNA-33a-5p in 20 samples from patients with LUSCs and 20 matching non-LUSC specimens by in-house quantitative real-time PCR (RT-qPCR). Relationship between miRNA-33a-5p expression and clinicopathological traits was investigated from materials derived from miRNA sequencing and miRNA microarrays. A pool standard mean difference (SMD) and summary receiver operating characteristic curves (SROC) were calculated to evaluate the integrated expression value of miRNA-33a-5p in LUSC. Twelve online platforms were applied to select potential target genes of miRNA-33a-5p. The differentially expressed genes (DEGs) of LUSC and the candidate target genes of miRNA-33a-5p were overlapped to acquire a set of specific genes for further analyses of the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and protein-protein interaction (PPI) network. miRNA-33a-5p overexpressed in LUSC was supported by 706 LUSC and 261 non-LUSC samples gathering from RT-qPCR, miRNA-seq, and public miRNA microarrays. The pooled SMD was 0.56 (95% CI: -0.01-1.05), and the area under the curve (AUC) of the SROC was 0.78 (95% CI: 0.74-0.82). A total of 240 genes were identified as potential target genes of miRNA-33a-5p for functional enrichment analyses; the results suggested that these target genes may participate in several vital biological processes that promote the proliferation and progression of LUSC. miRNA-33a-5p may play an essential role in the occurrence and development of LUSC by targeting hub genes (ETS1, EDNRB, CYR61, and LRRK2) derived from the PPI network. In summary, our results indicated that miRNA-33a-5p may contribute as a prospective therapeutic target in LUSC.

Downregulation of miRNA-126-3p is associated with progression of and poor prognosis for lung squamous cell carcinoma.

Lung squamous cell carcinoma (LUSC) is the main pathological type of pulmonary malignant tumors; at present, less than 10% of patients with advanced metastatic LUSC live for more than 5 years. We previously reported that low expression of miRNA-126-3p is associated with the occurrence and progression of lung adenocarcinoma (LUAD). Here, we examined expression of miRNA-126-3p in 23 samples from patients with LUSCs and 23 normal control specimens by quantitative real-time PCR (RT-qPCR). Associations between miRNA-126-3p expression and clinical features were studied from materials derived from Gene Expression Omnibus (GEO) chips and The Cancer Genome Atlas (TCGA) database. Twelve online platforms were used to identify candidate target genes of miRNA-126-3p. Further analyses of the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and protein-protein interaction (PPI) network were performed on the target genes. GEO microarray analysis, TCGA data mining, RT-qPCR, and integration analysis consistently reported low expression of miRNA-126-3p in LUSC. A total of 42 genes were identified as potential target genes of miRNA-126-3p from online platforms, GEO microarrays, and the TCGA database. GO and KEGG analyses demonstrated that the target genes are involved in several biological processes that promote the progression of LUSC. SOX2, E2F2, and E2F3 were selected as hub genes from the PPI network for further analysis. In summary, our results suggest that the low expression of miRNA-126-3p may play a role in promoting the development of LUSC and miRNA-126-3p may be a biomarker for LUSC early diagnosis and prognosis.

Expression levels and co­targets of miRNA­126­3p and miRNA­126­5p in lung adenocarcinoma tissues: Αn exploration with RT­qPCR, microarray and bioinformatic analyses.

Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer. Previous studies have found that many microRNAs (miRNAs), including miRNA­126­3p, may play a critical role in the development of LUAD. However, no study of LUAD has researched the synergistic effects and co­targets of both miRNA­126­3p and miRNA­126­5p. The present study used real­time quantitative polymerase chain reaction (RT­qPCR) to explore the expression values of miRNA­126­3p and miRNA­126­5p in 101 LUAD and 101 normal lung tissues. Ten relevant microarray datasets were screened to further validate the expression levels of miRNA­126­3p and ­5p in LUAD. Twelve prediction tools were employed to obtain potential targets of miRNA­126­3p and miRNA­126­5p. The results showed that both miRNA­126­3p and ­5p were expressed significantly lower in LUAD. A significant positive correlation was also present between miRNA­126­3p and ­5p expression in LUAD. In addition, lower expression of miRNA­126­3p and ­5p was indicative of vascular invasion, lymph node metastasis (LNM), and a later tumor/node/metastasis (TNM) stage of LUAD. The authors obtained 167 targets of miRNA­126­3p and 212 targets of miRNA­126­5p; 44 targets were co­targets of both. Eight co­target genes (IGF2BP1, TRPM8, DUSP4, SOX11, PLOD2, LIN28A, LIN28B and SLC7A11) were initially identified as key genes in LUAD. The results of the present study indicated that the co­regulation of miRNA­126­3p and miRNA­126­5p plays a key role in the development of LUAD, which also suggests a fail­proof mode between miRNA­3p and miRNA­126­5p.

The clinical value of miR-193a-3p in non-small cell lung cancer and its potential molecular mechanism explored in silico using RNA-sequencing and microarray data.

miR-193a-3p is a tumor-related miRNA playing an essential role in tumorigenesis and progression of non-small cell lung cancer (NSCLC). The objective of the present study was to investigate the relationship between miR-193a-3p expression and clinical value and to further explore the potential signaling of miR-193a-3p in the carcinogenesis of NSCLC. RNA-sequencing and microarray data were collected from the databases GEO, ArrayExpress and The Cancer Genome Atlas (TCGA). Furthermore, in silico assessments were performed to analyze the prospective pathways and networks of the target genes of miR-193a-3p. In total, 453 cases of NSCLC patients and 476 normal controls were included in blood samples, while 920 cases of NSCLC patients and 406 normal controls were included in tissue samples. The pooled positive likelihood ratio, the pooled negative likelihood ratio and the pooled diagnostic odds ratio were calculated to reflect the diagnostic value of miR-193a-3p in blood and tissue samples. Moreover, the areas under the curve of the summary receiver operating characteristic curve of blood and tissue were 0.64 and 0.79, respectively. In addition, we found a lower level of miR-193a in NSCLC tissues than in non-cancerous controls based on TCGA. A gene ontology (GO) enrichment analysis demonstrated that miR-193a-3p could be related to key signaling pathways in NSCLC. Also, several vital pathways were illustrated by KEGG. Lower expression of miR-193a-3p in tissue samples of NSCLC may be associated with tumorigenesis and be a predictor of deterioration of NSCLC patients, and pathway analysis revealed crucial signaling pathways correlated with the incidence and progress of NSCLC.

A meta-analysis and bioinformatics exploration of the diagnostic value and molecular mechanism of miR-193a-5p in lung cancer.

Lung cancer is a leading cause of mortality worldwide and despite recent improvements in lung cancer treatments patient mortality remains high. miR-193a-5p serves a crucial role in the initiation and development of cancer; it is necessary to understand the underlying molecular mechanisms of miR-193a-5p in lung cancer, which may enable the development of improved clinical diagnoses and therapies. The present study investigated the diagnostic value of peripheral blood and tissue miR-193a-5p expression using a microarray meta-analysis. Peripheral blood miR-193a-5p was revealed to be upregulated in patients with lung cancer. The pooled area under the curve (AUC) was 0.67, with a sensitivity and specificity of 0.74 and 0.56, respectively. Conversely, the peripheral tissue miR-193a-5p expression in patients with lung cancer was significantly downregulated. The pooled AUC was 0.83, and the sensitivity and specificity were 0.65 and 0.89, respectively. Through bioinformatics analysis, three Kyoto Encyclopedia of Genes and Genomes (KEGG) terms, pathways in cancer, prostate cancer and RIG-I-like receptor signaling pathway, were identified as associated with miR-193a-5p in lung cancer. In addition, in lung cancer, six key miR-193a-5p target genes, receptor tyrosine-protein kinase erbB-2 (ERBB2), nuclear cap-binding protein subunit 2 (NCBP2), collagen α-1(I) chain (COL1A1), roprotein convertase subtilisin/kexin type 9 (PCSK9), casein kinase II subunit α (CSNK2A1) and nucleolar transcription factor 1 (UBTF), were identified, five of which were significantly upregulated (ERBB2, NCBP2, COL1A1, CSNK2A1 and UBTF). The protein expression of ERBB2, NCBP2, COL1A1, CSNK2A1 and UBTF was also upregulated. NCBP2 and CSNK2A1 were negatively correlated with miR-193a-5p. The results demonstrated that miR-193a-5p exhibited opposite expression patterns in peripheral blood and tissue. Upregulated peripheral blood miR-193a-5p and downregulated tissue miR-193a-5p may be promising diagnostic biomarkers in lung cancer. In addition, the KEGG terms pathways in cancer, prostate cancer and RIG-I-like receptor signaling pathway may suggest which pathways serve vital roles in lung cancer by regulating miR-193a-5p. In addition, six genes, ERBB2, COL1A1, PCSK9, UBTF and particularly NCBP2 and CSNK2A1, may be key target genes of miR-193a-5p in lung cancer.

Oncogenic role of miR­183­5p in lung adenocarcinoma: A comprehensive study of qPCR, in vitro experiments and bioinformatic analysis.

Despite the fact that previous studies have reported the aberrant expression of miR­183­5p in lung adenocarcinoma (LUAD), the oncogenic role of miR­183­5p in LUAD and its underlying mechanisms have remained elusive. Hence, we attempted to elucidate the clinicopathological significance of miR­183­5p expression in LUAD and identify the biological function of miR­183­5p in LUAD in this study. Meta­analysis of Gene Expression Omnibus (GEO) data, data mining of The Cancer Genome Atlas (TCGA) and real­time quantitative polymerase chain reaction (qPCR) were performed to evaluate the clinicopathological significance of miR­183­5p in LUAD. Then, the effect of miR­183­5p on cell growth in LUAD was assessed by in vitro experiments. Additionally, the target genes of miR­183­5p were identified via miRWalk v.2.0 and TCGA. Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Disease Ontology (DO) analysis were further carried out for the target genes. The targetability between target genes in key KEGG pathways and miR­183­5p was validated by independent samples t­test, Pearson's correlation test and immunohistochemistry results from the Human Protein Atlas (HPA). According to the results, miR­183­5p was overexpressed in LUAD and exhibited significant diagnostic value. Moreover, miR­183 expression was associated with tumor progression in the TCGA data. In vitro experiments revealed the positive influence of miR­183­5p on cell viability and proliferation as well as the negative effect of miR­183­5p on caspase­3/7 activity in LUAD, which supports the finding that target genes of miR­183­5p are mainly enriched in gene pathways containing cell adhesion molecules (CAMs) and gene pathways important in cancer. Therefore, we conclude that miR­183­5p acts as an oncogene in LUAD and participates in the pathogenesis of LUAD via the interaction networks of its target genes.

Long non­coding RNAs in small cell lung cancer: A potential opening to combat the disease (Review).

Lung cancer is the top cause of cancer­associated mortality in men and women worldwide. Small cell lung cancer (SCLC) is a subtype that constitutes ~15% of all lung cancer cases. Long non­coding RNAs (lncRNAs), possessing no or limited protein­coding ability, have gained extensive attention as a potentially promising avenue by which to investigate the biological regulation of human cancer. lncRNAs can modulate gene expression at the transcriptional, post­transcriptional and epigenetic levels. The current review highlights the developing clinical implications and functional roles of lncRNAs in SCLC, and provides directions for their future utilization in the diagnosis and treatment of SCLC.

Utility of miR­133a­3p as a diagnostic indicator for hepatocellular carcinoma: An investigation combined with GEO, TCGA, meta­analysis and bioinformatics.

Increasing evidence has demonstrated that microRNA (miR)­133a­3p is an important regulator of hepatocellular carcinoma (HCC). In the present study, the diagnostic role of miR­133a­3p in HCC, and the potential functional pathways, were both explored based on publicly available data. Eligible microarray datasets were collected from NCBI Gene Expression Omnibus (GEO) database and ArrayExpress database. The data related to HCC and matched adjacent normal tissues were also downloaded from The Cancer Genome Atlas (TCGA). Published studies reporting the association between miR­133a­3p expression and HCC were reviewed from multiple databases. By combining the data derived from three sources (GEO, TCGA and published studies), the authors analyzed the comprehensive relationship between miR­133a­3p expression and clinicopathological features of HCC. Eventually, putative targets of miR­133a­3p in HCC were selected for further bioinformatics prediction. A total of eight published microarray datasets were gathered, and the pooled results demonstrated that the expression of miR­133a­3p in the tumor group was lower than that in normal groups [standardized mean difference (SMD)=­0.54; 95% confidence interval (CI), ­0.74 to ­0.35; P<0.001]. Consistently, the level of miR­133a­1 in HCC was reduced markedly compared to normal tissues (P<0.001) based on TCGA data, and the AUC value of low miR­133a­1 expression for HCC diagnosis was 0.670 (P<0.001). Furthermore, the combined SMD of all datasets (GEO, TCGA and literature) suggested that significant difference was observed between the HCC group and the normal control group, and lower miR­133a­3p expression in HCC group was noted (SMD=­0.69; 95% CI, ­1.10 to ­0.29; P=0.001). In addition, the authors discovered five key genes of the calcium signaling pathway (NOS1, ADRA1A, ADRA1B, ADRA1D and TBXA2R) that may probably be targeted by miR­133a­3p in HCC. The study reveals that miR­133a­3p may function as a tumor suppressor in HCC. The prospective novel pathways and key genes of miR­133a­3p could offer potential biomarkers for HCC; however, the predictions require further confirmation.