Expression of microRNA miR-126 and miR-200c is associated with prognosis in patients with non-small cell lung cancer

Integrative Biomarker Panel for Improved Lung Cancer Diagnosis Using Plasma microRNAs and Sputum Bacterial DNA

This study aimed to evaluate if integrating diverse molecular biomarkers in plasma and sputum could improve the diagnosis of lung cancer. The study analyzed miRNAs in plasma and bacterial DNA in sputum from 58 lung cancer patients and 62 cancer-free smokers using droplet digital PCR. The individual plasma miRNA and sputum bacterial biomarkers had sensitivities of 62-71% and specificities of 61-79% for diagnosing lung cancer. A panel of plasma miRNA or sputum bacterial biomarkers produced sensitivities of 79-85% and specificities of 74-82%. An integromic signature consisting of two miRNAs in plasma and three bacterial biomarkers in sputum had a higher sensitivity (87%) and specificity (89%) compared to individual biomarkers. The signature's diagnostic value was confirmed in a validation cohort of 56 lung cancer patients and 59 controls, independent of tumor stage, histological type, and demographic factors. Integrating diverse molecular biomarkers in plasma and sputum could improve the diagnosis of lung cancer.

Plasma-Based microRNA Expression Analysis in Advanced Stage NSCLC Patients Treated with Nivolumab

Simple Summary

Nivolumab (anti-PD-1 inhibitor) is the first monoclonal antibody approved for the treatment of NSCLC, with research results showing that patients who had received previous lines of therapy had a better response to this treatment and better overall survival. Tissue-level analyses fail to capture the dynamic tumor-host relationship, in contrast to circulating biomarkers, which can reflect the systemic response of the tumor, allowing for repeated sampling and monitoring. In the context of liquid biopsy, microRNAs are studied as biomarkers of immunotherapy efficacy based on their role in regulating antitumor immunity. The present study suggests that miR-200c and miR-34a plasma expression levels have a prognostic role in patients with advanced NSCLC receiving Nivolumab. It further supports that the expression profile of circulating immunomodulatory microRNAs provides information on the survival of patients with advanced NSCLC receiving Nivolumab and could represent promising circulating biomarkers that may provide information about patients’ responses to immunotherapy.

Abstract

Since circulating microRNAs (miRNAs) are involved in the modulation of the immune response, they are tested as liquid biopsy-based biomarkers in patients with NSCLC treated with immunotherapy. We analyzed the expression levels and examined the clinical significance of immunoregulatory miRNAs involved in immune checkpoint regulation (miR-34a, miR-200b, miR-200c), T-cell activity (miR-155), and the function of myeloid-derived suppressive cells (MDSCs) (miR-223) or regulatory T lymphocytes (Tregs) (miR-146a), in patients with advanced NSCLC (N = 69) treated with anti-PD-1 (Nivolumab) immunotherapy as 2nd or 3rd line of treatment therapy. Plasma levels of circulating miRNAs were analyzed by RT-qPCR before the initiation of immunotherapy. Expression of miR-34a, miR-146a, mir-200c, and miR-223 was found to be associated with response to immunotherapy. High miR-200c expression emerged as an independent prognostic factor for inferior overall survival in all patients with NSCLC (OS, HR: 2.243, 95% CI: 1.208–4.163; p = 0.010) and in patients with non-Squamous (non-SqCC) subtype (N = 38) (HR: 2.809, 95% CI: 1.116–7.074; p = 0.028). Low miR-34a expression independently predicted for shorter OS (HR: 3.189, 95% CI: 1.193–8.527; p = 0.021) in the non-SqCC subgroup. Our findings suggest that alterations in circulating miR-200c and miR-34a expression levels are associated with the response and outcome in patients with advanced NSCLC treated with anti-PD1 immunotherapy.

MiR-200c promotes papillary thyroid cancer cell proliferation, migration, and invasion by downregulating PTEN

MiR-200c has been reported in several types of human cancer. Nevertheless, the expression profile and biological functions of miR-200c remain uncovered papillary thyroid cancer (PTC). The expression level of miR-200c was evaluated in PTC tissues using RT-qPCR. Survival analysis was performed in a cohort of 88 PTC patients. The effects of miR-200c on cell proliferation, migration, and invasion capacities were analyzed using CCK-8 and transwell assays. Target genes of miR-200c were assessed using luciferase reporter assay, RT-qPCR, Western blot and rescue experiments. MiR-200c was found to be upregulated in human PTC tissues and closely associated with pN stage and distant metastasis. High expression of miR-200c was associated with poor clinical prognosis in PTC patients. Whilst overexpression of miR-200c was demonstrated to promote the proliferation, migration, and invasion of PTC cells; knockdown of miR-200c showed an opposite inhibitory effect. Bioinformatics analysis and luciferase reporter assays confirmed that PTEN is a downstream target of miR-200c. Functional assays demonstrated that PTC cell proliferation, migration, and invasion were promoted by miR-200c via negative regulation of PTEN. Finally, overexpression of PTEN was shown to partially reverse the tumor promoting effect of miR-200c. In conclusion, this study indicates that miR-200c is a crucial prognostic biomarker of PTC, and that targeting of miR-200c/ PTEN axis may be of therapeutic significance in PTC patients.

Circulating Biomarkers for Early Stage Non-Small Cell Lung Carcinoma Detection: Supplementation to Low-Dose Computed Tomography

Lung cancer is currently the leading cause of cancer death in both developing and developed countries. Given that lung cancer has poor prognosis in later stages, it is essential to achieve an early diagnosis to maximize patients’ overall survival. Non-small cell lung cancer (NSCLC) is the most common form of primary lung cancer in both smokers and non-smokers. The current standard screening method, low‐dose computed tomography (LDCT), is the only radiological method that demonstrates to have mortality benefits across multiple large randomized clinical trials (RCT). However, these RCTs also found LDCT to have a significant false positive rate that results in unnecessary invasive biopsies being performed. Due to the lack of both sensitive and specific screening methods for the early detection of lung cancer, there is an urgent need for alternative minimally or non-invasive biomarkers that may provide diagnostic, and/or prognostic information. This has led to the identification of circulating biomarkers that can be readily detectable in blood and have been extensively studied as prognosis markers. Circulating microRNA (miRNA) in particular has been investigated for these purposes as an augmentation to LDCT, or as direct diagnosis of lung cancer. There is, however, a lack of consensus across the studies on which miRNAs are the most clinically useful. Besides miRNA, other potential circulating biomarkers include circulating tumor cells (CTCs), circulating tumor DNA (ctDNAs) and non-coding RNAs (ncRNAs). In this review, we provide the current outlook of several of these biomarkers for the early diagnosis of NSCLC.

Extracellular Vesicle miR-200c Enhances Gefitinib Sensitivity in Heterogeneous EGFR-Mutant NSCLC

Intratumoral heterogeneity in epidermal growth factor receptor (EGFR)-mutant mutant non-small-cell lung cancer (NSCLC) explains the mixed responses to EGFR-tyrosine kinase inhibitors (TKIs). However, some studies showed tumors with low abundances of EGFR mutation still respond to EGFR-TKI, and the mechanism remained undetermined. Extracellular vesicles (EVs) can transmit antiapoptotic signals between drug-resistant and drug-sensitive cells. Herein, we profiled EVs from EGFR-mutant cells to identify a novel mechanism explaining why heterogenous EGFR-mutant NSCLC patients still respond to EGFR-TKIs. We first demonstrated that the EVs from EGFR-mutant changes the wild-type cells’ sensitivity to gefitinib by adding EV directly or coculturing EGFR wild-type (CL1-5) cells and EGFR-mutant (PC9) cells. In animal studies, only the combined treatment of PC9 EV and gefitinib delayed the tumor growth of CL1-5 cells. MicroRNA analysis comparing EV miRNAs from PC9 cells to those from CL1-5 cells showed that mir200 family members are most abundant in PC9 EVs. Furthermore, mir200a and mir200c were found upregulated in plasma EVs from good responders to EGFR-TKIs. Finally, the transfection of CL1-5 cells with miR200c inactivates downstream signaling pathways of EGFR, the EMT pathway, and enhances gefitinib sensitivity. Overall, our results suggest that in heterogeneous EGFR-mutant NSCLC, tumor cells transmit EV miRNAs that may affect sensitivity to EGFR-TKIs and provide potential prognostic biomarkers for EGFR-mutant NSCLC.

MiRNA-200C expression in Fanconi anemia pathway functionally deficient lung cancers

The Fanconi Anemia (FA) pathway is essential for human cells to maintain genomic integrity following DNA damage. This pathway is involved in repairing damaged DNA through homologous recombination. Cancers with a defective FA pathway are expected to be more sensitive to cross-link based therapy or PARP inhibitors. To evaluate downstream effectors of the FA pathway, we studied the expression of 734 different micro RNAs (miRNA) using NanoString nCounter miRNA array in two FA defective lung cancer cells and matched control cells, along with two lung tumors and matched non-tumor tissue samples that were deficient in the FA pathway. Selected miRNA expression was validated with real-time PCR analysis. Among 734 different miRNAs, a cluster of microRNAs were found to be up-regulated including an important cancer related micro RNA, miR-200C. MiRNA-200C has been reported as a negative regulator of epithelial-mesenchymal transition (EMT) and inhibits cell migration and invasion by promoting the upregulation of E-cadherin through targeting ZEB1 and ZEB2 transcription factors. miRNA-200C was increased in the FA defective lung cancers as compared to controls. AmpliSeq analysis showed significant reduction in ZEB1 and ZEB2 mRNA expression. Our findings indicate the miRNA-200C potentially play a very important role in FA pathway downstream regulation.

MiR-200c-3p suppression is associated with development of acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in EGFR mutant non-small cell lung cancer via a mediating epithelial-to-mesenchymal transition (EMT) process

BACKGROUND

EGFR-mutant lung cancer inevitably develops resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs).

OBJECTIVE

To investigate the clinical relevance of microRNAs (miRNAs) in TKI therapy response and resistance.

METHODS

We performed a miRNA PCR array analysis and used The Cancer Genome Atlas (TCGA) database to identify potential miRNAs related to EGFR TKIs resistance. We then correlated miRNA expression in 70 surgical and 50 malignant pleural effusion specimens with patient outcomes in those with non-small cell lung carcinoma. Molecular manipulation was performed in EGFR mutant lung cancer cells to assess the effect of miR-200c-3p on cell migratory ability and EGFR-TKI sensitivity.

RESULTS

We identified miR-200c-3p and miR-203a-3p as potential EGFR TKI resistance regulators via their modulation of epithelial-to-mesenchymal transition (EMT). MiR-200c-3p and miR-203a-3p were down-regulated in EGFR TKI-resistant cell lines. Progression-free survival (PFS) with EGFR-TKI treatment of patients with high miR-200c-3p expression, but not miR-203a-3p, in the specimens was significantly longer than that of patients with low expression. MiR-200c-3p overexpression inhibited the EMT process in EGFR TKI resistance cell lines and promoted cell death. MiR-200c-3p silencing in EGFR TKI sensitive cell lines increased drug resistance.

CONCLUSION

MiR-200c-3p plays a role in sensitivity to EGFR TKIs via modulating EMT process.

Exosomal miR-126 blocks the development of non-small cell lung cancer through the inhibition of ITGA6

Background

Exosomes, emerging mediators of intercellular communication, are reported to transfer certain non-coding RNAs, such as microRNAs (miRNAs), which play a crucial role in cancer progression. The objective of this study was to determine the function of exosomal miR-126 and provide a novel mechanism of miR-126 action in NSCLC.

Methods

The morphology of exosomes was identified by transmission electron microscope (TEM), and the exosomal surface markers were quantified by western blot. The expression of miR-126 and integrin alpha-6 (ITGA6) mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR), and ITGA6 protein expression was determined by western blot. For functional analyses, cell proliferation was assessed by colony formation assay and MTT assay. Cell cycle and cell apoptosis were monitored using flow cytometry assay. Cell migration and invasion were determined by transwell assay. ITGA6 was predicted as a target of miR-126 by bioinformatics analysis, which was verified by dual-luciferase reporter assay. The role of exosomal miR-126 in vivo was determined by Xenograft tumor models.

Results

NSCLC serum-derived exosomes harbored low expression of miR-126 and promoted NSCLC cell proliferation, cell cycle progression, cell migration and invasion. NSCLC serum-derived exosomes loaded with miR-126 mimic inhibits NSCLC cell proliferation, colony formation, migration and invasion but induced cell cycle arrest and apoptosis. Besides, exosomal miR-126 also blocked tumor growth in vivo. In mechanism, ITGA6 was a target of miR-126, and exosomal miR-126 weakened these NSCLC cell malignant behaviors and inhibited tumor growth by degrading the expression of ITGA6.

Conclusion

Exosomal miR-126 blocked the progression of NSCLC through the mediation of its target gene ITGA6, and exosomal miR-126 might be used as a promising biomarker for NSCLC therapy.

Bioinformatics analysis to determine the prognostic value and prospective pathway signaling of miR-126 in non-small cell lung cancer

Background

MicroRNAs (miRNAs) have been demonstrated to play crucial roles in the initiation and development of non-small cell lung cancer (NSCLC). However, further investigation of the specific role of miR-126 in NSCLC is still required.

Methods

An analysis of miR-126 expression in NSCLC was carried out using the Gene Expression Omnibus (GEO) database, and a literature review was also performed. The differentially expressed genes (DEGs) in three mRNA datasets, GSE18842, GSE19804, and GSE101929, from GEO were identified. Following the prediction of hsa-miR-126-5p target genes by TargetScan, the overlap of miR-126 target genes with DEGs in NSCLC was examined. After that, Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed. Finally, an analysis to identify the impact of hub genes on the prognosis of NSCLC was carried out on the basis of a protein-protein interaction (PPI) network constructed using STRING and Cytoscape.

Results

The data in the literature review revealed a trend that miR126 was downregulated in NSCLC. The number of both NSCLC-related and miR-126-related DEGs was 187. Dozens of DEGs were significantly enriched in biological regulation, cell membrane binding, and signal receptor binding. In the PPI network analysis, 3 of 10 identified hub genes, namely NCAPG, MELK, and KIAA0101, were obviously related to poor prognosis in NSCLC; the survival rate was low among patients with high expression levels of these genes. Furthermore, through network analysis, TPX2, HMMR, and ANLN were identified as recessive miR-126-related genes that may be involved in NSCLC.

Conclusions

MiR-126 plays an essential role in the biological processes of NSCLC through binding to target genes and influences the prognosis of patients with the disease.

Integrative p53, micro-RNA and Cathepsin Protease Co-Regulatory Expression Networks in Cancer

Simple Summary

This article describes an emerging area of significant interest in cancer and cell death and the relationships shared by these through the transcriptional regulation of cathepsin protease genes by micro-RNAs that are connected to p53 activation. While it has been demonstrated that the p53 protein can directly regulate some cathepsin genes and the expression of their upstream regulatory micro-RNAs, very little is known about what input the p53 isoform proteins may have in regulating this relationship. Herein, we draw attention to this important regulatory aspect in the context of describing mechanisms that are being established for the micro-RNA regulation of cathepsin protease genes and their collective use in diagnostic or prognostic assays.

Abstract

As the direct regulatory role of p53 and some of its isoform proteins are becoming established in modulating gene expression in cancer research, another aspect of this mode of gene regulation that has captured significant interest over the years is the mechanistic interplay between p53 and micro-RNA transcriptional regulation. The input of this into modulating gene expression for some of the cathepsin family members has been viewed as carrying noticeable importance based on their biological effects during normal cellular homeostasis and cancer progression. While this area is still in its infancy in relation to general cathepsin gene regulation, we review the current p53-regulated micro-RNAs that are generating significant interest through their regulation of cathepsin proteases, thereby strengthening the link between activated p53 forms and cathepsin gene regulation. Additionally, we extend our understanding of this developing relationship to how such micro-RNAs are being utilized as diagnostic or prognostic tools and highlight their future uses in conjunction with cathepsin gene expression as potential biomarkers within a clinical setting.

MicroRNA-126: A new and promising player in lung cancer

Lung cancer is one of the most common malignant tumors associated with cancer death; however, the mechanisms involved in lung tumor development have not been completely elucidated, which impedes the advancement of clinical diagnosis and therapy. MicroRNA-126 (miR-126) is an important member of the microRNA family and is encoded by intron 7 of epidermal growth factor-like domain-containing gene 7. Increasing evidence has demonstrated that miR-126, as a distinct endothelial-enriched miRNA and new tumor suppressor gene, serves a promising role in the occurrence, development and metastasis of various types of cancer, including liver cancer, colorectal cancer, melanoma and lung cancer. In the present review, the current knowledge of the role of miR-126 in lung cancer growth, metastasis, diagnosis and prognosis as well as therapy was summarized, which may provide new insights on the biological roles of miRNAsin lung cancer and facilitate the ultimate development of miRNA-based therapies in clinical patients with non-small cell lung cancer.

Meta-analysis of diagnostic and prognostic value of miR-126 in non-small cell lung cancer

In recent years, many studies on the relationship between the expression of microRNA-126 (miR-126) and the diagnostic and prognostic value of non-small cell lung cancer (NSCLC) have been made, but the results were still controversial. The aim is to explore the expression of miR-126 and the diagnosis and prognosis value of NSCLC, and to provide relevant evidence for clinical diagnosis and treatment. Literature related to miR-126 and NSCLC were searched in PubMed, Embase, Cochrane Library, Web of Science, CNKI, and Wanfang from the inception to February 2020. Stata 15.0 was used for meta-analysis. The diagnostic value data were used to calculate the pooled sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and the prognostic value data were used to calculate the pooled risk ratio (hazard ratio, HR) of overall survival (OS) and its 95% confidence interval (95% CI). Thirteen studies were included, among which five were related to diagnosis containing 439 patients and 463 healthy controls, and eight related to prognosis containing 1102 patients. The results of miR-126 expression and diagnostic value of NSCLC showed that the pooled sensitivity was 0.83 (95% CI: 0.59-0.94), specificity = 0.83 (95% CI: 0.71-0.90), PLR = 4.78 (95% CI: 2.97-7.69), NLR = 0.20 (95% CI: 0.08-0.54), DOR = 23.48 (95% CI: 7.87-70.10), and the area under the summ ary receiver operating characteristic curve (SROC) was 0.89 (95% CI: 0.86-0.91). The results of prognostic value indicated that the expression of miR-126 was related to the OS of NSCLC (HR = 0.79, 95% CI: 0.63-0.98). In conclusion, the expression of miR-126 has medium diagnostic value, and it is related to the prognosis of patients with NSCLC, with poor prognosis of miR-126 low expression.

A novel circular RNA circFN1 enhances cisplatin resistance in gastric cancer via sponging miR-182-5p

Cisplatin (CDDP) is commonly used for gastric cancer (GC) chemotherapy. However, after several CDDP-based treatment cycles, patients always acquire chemotherapy resistance, which limits the overall clinical efficacy of the treatment. Clarification of the mechanisms responsible for CDDP resistance is required to improve therapeutic outcomes for patients. Circular RNAs (circRNAs) are noncoding RNAs involved in the pathogenesis of cancer, although their role in the mechanism underlying CDDP resistance in GC remains unknown. In the present study, we explored the underlying roles of circRNAs in the modulation of CDDP resistance in CDDP-sensitive and CDDP-resistant human GC cells. Using RNA sequencing and quantitative reverse transcription polymerase chain reaction, expression of circFN1 (originating from exons 10, 11, and 12 of the FN1 gene hsa_circ_0058147) was higher in CDDP-resistant GC cells and tissues. CircFN1 upregulation in GC patients treated by CDDP was significantly correlated with aggressive biological behavior. CircFN1 promoted viability and inhibited apoptosis of GC cells exposed to CDDP in vivo and in vitro. Furthermore, circFN1 suppressed GC cell apoptosis by "sponging" miR-182-5p. These findings demonstrate the involvement of circFN1 in CDDP resistance of GC and implicate circFN1 as a therapeutic target for GC patients treated with CDDP. It provides novel evidence of the function of circRNAs as microRNA sponges and highlight a potential therapeutic target for extinguishing CDDP resistance in patients with GC.

Prognostic Role of Circulating miRNAs in Early-Stage Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the primary cause of cancer-related death worldwide, with a low 5-year survival rate even in fully resected early-stage disease. Novel biomarkers to identify patients at higher risk of relapse are needed. We studied the prognostic value of 84 circulating microRNAs (miRNAs) in 182 patients with resected early-stage NSCLC (99 adenocarcinoma (ADC), 83 squamous cell carcinoma (SCC)) from whom peripheral blood samples were collected pre-surgery. miRNA expression was analyzed in relation to disease-free survival (DFS) and overall survival (OS). In univariable analyses, five miRNAs (miR-26a-5p, miR-126-3p, miR-130b-3p, miR-205-5p, and miR-21-5p) were significantly associated with DFS in SCC, and four (miR-130b-3p, miR-26a-5p, miR-126-3p, and miR-205-5p) remained significantly associated with OS. In ADC, miR-222-3p, miR-22-3p, and mir-93-5p were significantly associated with DFS, miR-22-3p remaining significant for OS. Given the high-dimensionality of the dataset, multivariable models were obtained using a regularized Cox regression including all miRNAs and clinical covariates. After adjustment for disease stage, only miR-126-3p showed an independent prognostic role, with higher values associated with longer DFS in SCC patients. With regard to ADC and OS, no miRNA remained significant in multivariable analysis. Further investigation into the role of miR-126 as a prognostic marker in early-stage NSCLC is warranted.

The Significance Role of microRNA-200c as a Prognostic Factor in Various Human Solid Malignant Neoplasms: A Meta-Analysis

Objective: The aim of this study was to conduct a meta-analysis of 49 relevant studies to evaluate the prognostic value of miRNA-200c in various human malignant neoplasms.

Methods: All relevant studies were identified by searching PubMed, Embase and Web of Science until August 15^st, 2018. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) of miRNA-200c for overall survival (OS) and progression-free survival (PFS)/recurrence-free survival (RFS)/disease-free survival (DFS) were calculated to investigate such associations.

Results: Overall, 49 eligible studies were included in this meta-analysis. Our results showed that high expression of miRNA-200c was significantly correlated with a poor OS in cancer (pooled HR = 1.32, 95% CI: 1.06-1.65), but was not significantly correlated with PFS/RFS/DFS in cancer (pooled HR=1.05, 95% CI: 0.84-1.23). In our subgroup analysis, high miRNA-200c expression predicted a significantly worse OS (pooled HR = 1.50, 95% CI: 1.12-2.01) only in Caucasians. Moreover, high miRNA-200c expression even showed significantly poor OS (pooled HR = 1.88, 95% CI: 1.39-2.54) in blood samples. In addition, a significantly unfavorable OS (pooled HR = 2.69, 95% CI: 1.49-4.85) and (pooled HR = 2.66, 95% CI: 1.07-6.59) associated with up-regulated miRNA-200c expression were observed in breast cancer and endometrial cancer, respectively. Besides, high miRNA-200c expression also showed significantly poor PFS/RFS/DFS (pooled HR=1.66, 95% CI: 1.03-2.67) in breast cancer.

Conclusions: Our findings indicated that high miRNA-200c expression was a promising biomarker for patient survival and disease progression in malignant tumors, especially in breast cancer and endometrial cancer. Considering the insufficient evidence, further large-scale researches and clinical studies were needed to verify these results.

Long Non-coding RNA PVT1 Competitively Binds MicroRNA-424-5p to Regulate CARM1 in Radiosensitivity of Non-Small-Cell Lung Cancer

Accumulating evidence revealed that dysregulated long non-coding RNAs (lncRNAs) were involved in tumorigenesis and progression. This study is supposed to reveal the effects of lncRNA PVT1 on the radiosensitivity of non-small-cell lung cancer (NSCLC) via the microRNA (miR)-424-5p/lncRNA PVT1/CARM1 signaling pathway. Differentially expressed lncRNA was filtrated. The co-expressed gene of lncRNA was predicted, and gene ontology analysis was performed to find out the genes associated with NSCLC radiosensitivity. The miR that was combined with lncRNA and mRNA was filtrated. Two cell lines with the highest expressed PVT1 were selected, followed by transfection with a series of different mimic, inhibitor, or siRNA. RIP assay was employed for the interaction between PVT1 and CARM1. The regulatory effect of miR-424-5p on cell proliferation, migration, invasion, cycle, and apoptosis was investigated. PVT1 was the most remarkable lncRNA that upregulated in NSCLC. CARM1 co-expressed with lncRNA PVT1 and associated with NSCLC radiosensitivity. Both lncRNA PVT1 and CARM1 can combine with miR-424-5p. Increased PVT1, CARM1, MMP-2, MMP-9, and Bcl-2 and decreased miR-424-5p and Bax were found in NSCLC tissues. PVT1 was targeted by miR-424-5p. After silencing of PVT1 or overexpressed miR-424-5p, decreased PVT1, CARM1, MMP-2, MMP-9, and Bcl-2 inhibited cell proliferation, migration, and invasion but promoted miR-424-5p, Bax, and cell apoptosis. The present study confirms the radiosensitivity of NSCLC radiotherapy can be increased by siRNA-PVT1 and overexpressed miR-424-5p.

Inhibition of microRNA‑939 suppresses the development of human non‑small cell lung cancer via the upregulation of tissue inhibitor of metalloproteinases 2

Numerous microRNAs (miRNA/miRs) have been reported to be associated with the initiation and progression of non‑small cell lung cancer (NSCLC). The aim of the present study was to examine the expression and biological role of miR‑939 in human NSCLC, in vitro. Reverse transcription‑quantitative polymerase chain reaction analysis was used to evaluate the expression of miR‑939 in NSCLC tissues. Cell Counting Kit‑8, 5‑ethynyl‑29‑deoxyuridine and Transwell assays were also used to determine the effects of miR‑939 on tumor cell proliferation and invasion in two human NSCLC cell lines (H1299 and SPCA1). Furthermore, tissue inhibitor of metalloproteinases 2 (TIMP2) was confirmed to be a target of miR‑939 by luciferase reporter assay, western blotting and bioinformatics analysis. Following downregulation of miR‑939 expression, cell proliferative and invasive abilities were significantly suppressed. Collectively, these findings indicated that the knockdown of miR‑939 may inhibit cell proliferation and invasion by regulating the expression of TIMP2 in NSCLC cells. Thus, miR‑939 may be a potential target in the treatment of NSCLC, although this requires further investigation.

Negative correlation of cytoplasm TIMP3 with miR-222 indicates a good prognosis for NSCLC

Background

The aim of this study was to observe the expression of microRNA-222 (miR-222) and matrix metalloproteinase inhibitor 3 (TIMP3) in non-small cell lung cancer (NSCLC) and discuss their significance.

Methods

A total of 230 patients with NSCLC were enrolled in the observation group during the operation. Ninety-eight normal adjacent tissues were used as the control group. Two groups of miR-222 and TIMP3 were detected by in situ hybridization and immunohistochemistry. The distribution of miR-222 and TIMP3 in A549/H358/PC9 cells was observed by immunofluorescence. Chi-squared and Spearman correlation tests were used to analyze the relationship among miR-222, TIMP3 expression, and clinicopathological parameters of NSCLC. Kaplan-Meier and Cox proportional hazards regression were used to analyze the prognostic impact of miR-222 and TIMP3.

Results

Immunohistochemistry showed that the expression of miR-222 in lung cancer tissue was significantly higher, but TIMP3 was lower than that in normal lung tissue (P = 0.0001 for the former and P = 0.0002 for the latter). Meanwhile, miR-222 and TIMP3 were mainly distributed in the cytoplasm. Among them, cTIMP3 accounted for 70.29% (72/101), cmiR-222 for 59.35% (92/155), 14.85% for nTIMP3 (15/101), and 18.06% for nmiR-222 (28/155). There was a significant difference in distribution (both P < 0.0001). The expression of miR-222 and TIMP3 were negatively correlated in lung cancer tissues (r = -0.43, P = 0.0219). With the progression of clinical stage, the positive intensity of cTIMP3 showed a decreasing trend, while the cmiR-222 showed a reverse trend (the former P = 0.0024 and the latter P < 0.0001). In the Kaplan-Meier prognostic analysis, we found that the high expression of cTIMP3 could predict a better prognosis (P = 0.0040), whereas cmiR-222 was the opposite (P = 0.0016). Multivariate analysis shows that both can be used as independent factors.

Conclusion

TIMP3 expression in lung cancer is relatively low and has a negative correlation with lung cancer staging and prognosis, suggesting that it may play a defensive function in the development of lung cancer, while miR-222 has the opposite effect, and the expression of both proteins is negatively correlated, suggesting that in lung cancer progresses, both proteins may play some role together.

Plasma small ncRNA pair panels as novel biomarkers for early-stage lung adenocarcinoma screening

Background

Lung cancer is a major cause of cancer-related mortality worldwide, and around two-thirds of patients have metastasis at diagnosis. Thus, detecting lung cancer at an early stage could reduce mortality. Aberrant levels of circulating small non-coding RNAs (small ncRNAs) are potential diagnostic or prognostic markers for lung cancer. We aimed to identify plasma small ncRNA pairs that could be used for early screening and detection of lung adenocarcinoma (LAC).

Results

A panel of seven small ncRNA pair ratios could differentiate patients with LAC or benign lung disease from high-risk controls with an area under the curve (AUC) of 100.0%, a sensitivity of 100.0% and a specificity of 100.0% at the training stage (which included 50 patients with early-stage LAC, 35 patients with benign diseases and 29 high-risk controls) and an AUC of 90.2%, a sensitivity of 91.5% and a specificity of 80.4% at the validation stage (which included 44 patients with early-stage LAC, 32 patients with benign diseases and 51 high-risk controls). The same panel could distinguish LAC from high-risk controls with an AUC of 100.0%, a sensitivity of 100.0% and a specificity of 100.0% at the training stage and an AUC of 89.5%, a sensitivity of 85.4% and a specificity of 83.3% at the validation stage. Another panel of five small ncRNA pair ratios (different from the first) was able to differentiate LAC from benign disease with an AUC of 82.0%, a sensitivity of 81.1% and a specificity of 78.1% in the training cohort and an AUC of 74.2%, a sensitivity of 70.4% and a specificity of 72.7% in the validation cohort.

Conclusions

Several small ncRNA pair ratios were identified as markers capable of discerning patients with LAC from those with benign lesions or high-risk control individuals.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4862-z) contains supplementary material, which is available to authorized users.

Correlation between miR-200 Family Overexpression and Cancer Prognosis

The correlation between miR-200 family overexpression and cancer prognosis remains controversial. Therefore, we conducted a systematic review and meta-analysis by searching PubMed, Embase, Cochrane Library, China Biology Medicine disc (CBM), and China National Knowledge Infrastructure (CNKI) to identify eligible studies. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to evaluate the strength of the correlations. Additionally, different subgroup analyses and publication bias test were performed. Eventually, we analyzed 23 articles that included five tumor types and 3038 patients. Consequently, high expression of miR-200 family in various tumors was associated with unfavorable overall survival (OS) in both univariate (HR = 1.32, 95% CI: 1.14-1.54, P < 0.001) and multivariate (HR = 1.32, 95% CI: 1.16-1.49, P < 0.001) analyses. Likewise, a similar result was found in different subgroups of the patient source, cancer type, test method, sample source, miR-200 component, and sample size. However, no association of miR-200 family was detected with recurrence- or relapse-free survival (RFS) (univariate: HR = 1.02, 95% CI: 0.96-1.09, P = 0.47; multivariate: HR = 1.07, 95% CI: 1.00-1.14, P = 0.07), progression-free survival (PFS) (univariate: HR = 0.96, 95% CI: 0.54-1.70, P = 0.88; multivariate: HR = 1.17, 95% CI: 0.86-1.61, P = 0.32), and disease-free survival (DFS) (univariate: HR = 0.90, 95% CI: 0.74-1.09, P = 0.29; multivariate: HR = 0.98, 95% CI: 0.68-1.41, P = 0.90). Our findings have provided convincing evidence that miR-200 family overexpression suggested poor prognosis of various cancer types, which efforts may raise the potential use of miR-200 family for cancer prognosis in clinical practice.

miRNAs as biomarkers and for the early detection of non-small cell lung cancer (NSCLC)

Lung cancer is the most frequently diagnosed cancer and the most common cause of cancer death globally, of which 85% is non-small cell lung cancer (NSCLC). Early detection of NSCLC is essential to identify potential individuals for radical cure. Although low-dose computed tomography (LDCT) is recommended as standard screening with a mortality reduction of 20%, it displays a high false positive rate that poses an issue of overdiagnosis. MicroRNAs (miRNAs) are a group of small non-coding RNAs acting as important regulators in post-transcriptional gene expression and have been studied for their extensive role as novel biomarkers in NSCLC. Herein, we discuss the miRNA biology, its role in cancer, the potential of biomarkers both in cancer and NSCLC, and promising current publications of diagnostic biomarkers for early detection in NSCLC, especially studies in order to complement LDCT screening.

Expression of miR-200c and its clinicopathological significance in patients with colorectal cancer

MicroRNA-200c (miR-200c) is known to play a pivotal role in the regulation of epithelial-to-mesenchymal and mesenchymal-to-epithelial transition processes. However, the biological function of miR-200c in human carcinogenesis remains controversial. We examined the association of miR-200c expression with various clinicopathological factors, including KRAS mutation status and survival, in patients with colorectal cancer (CRC). The expression level of miR-200c was evaluated in 109 paired CRC and normal tissue samples using quantitative reverse transcription polymerase chain reaction. The KRAS mutation status of the CRC samples was determined using the PNAClamp™ KRAS Mutation Detection kit. Compared with the normal tissue group, miR-200c expression was significantly upregulated in the CRCs (P < .001). The expression of miR-200c was increased in CRCs with higher grade (P = .009), advanced stage (P = .042), and lymphovascular invasion (P = .003). Thirty-one CRCs (28.4%) had KRAS mutations in codon 12 or 13. CRCs with KRAS mutations had significantly higher miR-200c expression than CRCs with wild-type KRAS (P = .003). In survival analysis, high miR-200c expression was correlated with worse overall survival (P = .017) and recurrence-free survival (P = .048). Our results indicate that miR-200c is involved in tumor progression and aggressiveness in CRCs, and this oncogenic role of miR-200c may be triggered by activation of the KRAS signaling pathway.

A meta-analysis: microRNAs' prognostic function in patients with nonsmall cell lung cancer

Accumulating papers have demonstrated that microRNAs play an important role in the progression of lung cancer, mainly as oncogenic and tumor suppressive. Therefore, microRNAs may influence the survival of lung cancer patients. In this meta‐analysis, we evaluated the role of microRNAs in affecting the overall survival in nonsmall cell lung cancer (NSCLC) patients, which may provide valuable information for the treatment of nonsmall cell lung cancer. We used keywords to retrieve literatures from online databases PUBMED,EMBASE and Web of Science and included 12 studies into our investigation according to pre‐set criteria. Then, we analyzed the data with stata13.1 to evaluate the microRNAs role on the prognosis of NSCLC patients. NSCLC patients with higher microRNAs expression levels tend to show lower overall survival. HR (hazard ratio): 2.49, 95% CI (confidence interval): 1.84–3.37. Besides, both oncogenic and tumor suppressive microRNAs have an evident influence on prognosis with HR values of 2.60 (95% CI: 2.12–3.19) and 0.41 (95% CI: 0.05–0.34), respectively. microRNAs, especially from tissue, have an influence on overall survival of NSCLC patients, which indicates that microRNAs could serve as potential prognostic markers for NSCLC and may provide a treatment strategy for advanced NSCLC patients.

Potential use of microRNA-200c as a prognostic marker in non-small cell lung cancer

MicroRNAs (miRNAs/miRs) are a class of small, highly conserved non-coding RNAs that can serve either oncogenic or tumor-suppressive roles in a wide variety of tumors. miR-200c is a member of the miR-200 family whose specific role in non-small cell lung cancer (NSCLC) has not yet been elucidated. The purpose of the present study was to detect the expression level of miR-200c in NSCLC, and to analyze its association with clinicopathological factors and patient prognosis. The present study determined the expression levels of miR-200c in 110 tumor samples collected from patients diagnosed with NSCLC who underwent complete tumor resection with regional lymph node dissection, as assessed by reverse transcription-quantitative polymerase chain reaction. The association between the expression level of miR-200c and clinicopathological features and patient prognosis was also analyzed. The results showed that miR-200c overexpression was detected in 66 of the 110 cases and was significantly associated with positive lymph node metastasis (P<0.001). Univariate survival analysis demonstrated that high miR-200c expression, positive lymph node metastasis and advanced Tumor-Node-Metastasis (TNM) classification stage significantly predicted decreased 5-year disease-free survival rates (all P<0.05) and poor 5-year overall survival rates (all P<0.01), respectively. The results of multivariate Cox regression analysis showed that TNM stage and miR-200c expression retained its significance as an independent prognostic factor for unfavorable 5-year disease-free survival rates (P<0.05) and poor 5-year overall survival rates (P<0.01). The present findings suggest that miR-200c overexpression is significantly associated with poor survival rates in NSCLC and that miR-200c could play an oncogenic role. miR-200c may have clinical potential as a promising prognostic predictor for patients with NSCLC.

The prognostic value of miR-126 expression in non-small-cell lung cancer: a meta-analysis

OBJECTIVE

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related death. Growing evidence from recent studies have shown indicated that microRNA-126 (miR-126) played an important role in the progression of NSCLC. However, the potential value of miR-126 expression in prognosis of NSCLC remains to be fully elucidated. Here, we carried out a meta-analysis to assess the potential prognostic value of miR-126 for NSCLC.

METHODS

PubMed, Embase, the Cochrane library, Web of Science, CNKI and WanFang database, as well as the reference of included studies, were searched to recognize pertinent studies until April 30, 2017. New castle-Ottawa scale was used to evaluate the quality of studies. Pooled hazard ratio (HR) with 95% confidence interval (CI) for overall survival (OS) was extracted by using a fixed-effects or a random-effects model on the basis of heterogeneity. Publication bias was evaluated by using Begg's tests.

RESULTS

We identified four eligible trials involving 666 non-small-cell lung cancer patients in this meta-analysis. The results indicated that a high level of miR-126 played a favorable role in the overall survival (HR 0.73, 95% CI 0.61-0.86, fixed-effects model). There was no bias existed in this study.

CONCLUSIONS

Our study showed that high expression level of miR-126 was a promising positive factor for OS for non-small cell lung cancer patients, and miR-126 might be a potential target for non-small-cell lung cancer therapy in the future.

Diagnostic MicroRNA Biomarker Discovery for Non-Small-Cell Lung Cancer Adenocarcinoma by Integrative Bioinformatics Analysis

Lung cancer is the leading cause of cancer death and its incidence is ranked high in men and women worldwide. Non-small-cell lung cancer (NSCLC) adenocarcinoma is one of the most frequent histological subtypes of lung cancer. The aberration profile and the molecular mechanism driving its progression are the key for precision therapy of lung cancer, while the screening of biomarkers is essential to the precision early diagnosis and treatment of the cancer. In this work, we applied a bioinformatics method to analyze the dysregulated interaction network of microRNA-mRNA in NSCLC, based on both the gene expression data and the microRNA-gene regulation network. Considering the properties of the substructure and their biological functions, we identified the putative diagnostic biomarker microRNAs, some of which have been reported on the PubMed citations while the rest, that is, miR-204-5p, miR-567, miR-454-3p, miR-338-3p, and miR-139-5p, were predicted as the putative novel microRNA biomarker for the diagnosis of NSCLC adenocarcinoma. They were further validated by functional enrichment analysis of their target genes. These findings deserve further experimental validations for future clinical application.

Prognostic Role of the MicroRNA-200 Family in Various Carcinomas: A Systematic Review and Meta-Analysis

Background/Aims. The miRNA-200 (miR-200) family may act as key inhibitors of epithelial-to-mesenchymal transition. However, the potential prognostic value of miR-200s in various human malignancies remains controversial. This meta-analysis analyzed the associations between miR-200 levels and survival outcomes in a variety of tumors. Methods. Eligible published studies were identified by searching the Embase, PubMed, CINAHL, and Google scholar databases. Patient clinical data were pooled, and pooled hazard ratios (HRs) with 95% confidence intervals (95% CI) were used to calculate the strength of this association. Results. The pooled HRs suggested that high tissue expression of miR-200 family members was associated with better survival (overall survival [OS]: HR = 0.70, 95% CI 0.54–0.91; progression-free survival [PFS]: HR = 0.63, 95% CI 0.52–0.76) in thirty-four eligible articles. In contrast, higher expression of circulating miR-200 members was significantly associated with poor clinical outcome (OS, HR = 1.68, 95% CI 1.15–2.46; PFS, HR = 2.62, 95% CI 1.68–4.07). Conclusion. The results from this meta-analysis suggest that miR-200 family members are potential prognostic biomarkers in patients with various carcinomas. To apply these findings in the clinic, large prospective studies are needed to validate the prognostic values of miR-200s in individual cancer types.

Method for discriminating synchronous multiple lung cancers of the same histological type: miRNA expression analysis

With the development of imaging technology, an increasing number of synchronous multiple lung cancers (SMLCs) have been diagnosed in recent years. Patients with >1 tumor are diagnosed with either synchronous multiple primary lung cancers (SMPLCs) or other primary tumors and metastases. Clinical guidelines, histological characteristics, and molecular diagnostics have been used to discriminate SMPLCs from other multiple lung cancers. However, there is still ambiguity in the diagnosis of SMPLCs of the same histological type. We enrolled 24 patients with the same histological type of SMLCs and assessed their status using established clinical guidelines, comprehensive histological subtyping, and molecular analysis. The sum value of the differential microRNA (miRNA) expression profiles (ΔΔCt) with matched tumors was evaluated to discriminate SMPLCs of the same histological type from metastases. Twelve patients with lymph node metastases were included for comparison, and the sum value of the ΔΔCt of 5 miRNAs between primary tumors and lymph node metastases was <9. Patients definitively diagnosed with SMPLCs by integrated analysis were also classified as SMPLCs by miRNA analysis; 6 patients showed conflicting diagnoses by integrated and miRNA analysis and 14 were given the same classification. Analysis of miRNA expression profiles is considered to be a useful tool for discriminating SMPLCs from intrapulmonary metastases.

Epigenetics in non-small cell lung cancer: from basics to therapeutics

Lung cancer remains the number one cause of cancer-related deaths worldwide with 221,200 estimated new cases and 158,040 estimated deaths in 2015. Approximately 80% of cases are non-small cell lung cancer (NSCLC). The diagnosis is usually made at an advanced stage where the prognosis is poor and therapeutic options are limited. The evolution of lung cancer is a multistep process involving genetic, epigenetic, and environmental factor interactions that result in the dysregulation of key oncogenes and tumor suppressor genes, culminating in activation of cancer-related signaling pathways. The past decade has witnessed the discovery of multiple molecular aberrations that drive lung cancer growth, among which are epidermal growth factor receptor (EGFR) mutations and translocations involving the anaplastic lymphoma kinase (ALK) gene. This has translated into therapeutic agent developments that target these molecular alterations. The absence of targetable mutations in 50% of NSCLC cases and targeted therapy resistance development underscores the importance for developing alternative therapeutic strategies for treating lung cancer. Among these strategies, pharmacologic modulation of the epigenome has been used to treat lung cancer. Epigenetics approaches may circumvent the problem of tumor heterogeneity by affecting the expression of multiple tumor suppression genes (TSGs), halting tumor growth and survival. Moreover, it may be effective for tumors that are not driven by currently recognized druggable mutations. This review summarizes the molecular pathology of lung cancer epigenetic aberrations and discusses current efforts to target the epigenome with different pharmacological approaches. Our main focus will be on hypomethylating agents, histone deacetylase (HDAC) inhibitors, microRNA modulations, and the role of novel epigenetic biomarkers. Last, we will address the challenges that face this old-new strategy in treating lung cancer.

MicroRNA-126 inhibits tumor cell invasion and metastasis by downregulating ROCK1 in renal cell carcinoma

MicroRNAs (miRNAs) are involved in cancer development and progression. Renal cell carcinoma (RCC) frequently undergoes metastasis and has a high mortality rate. The current study measured miRNA-126 (miR-126) expression levels in 128 pairs of clear cell RCC and adjacent normal kidney tissue samples by reverse transcription-quantitative polymerase chain reaction, and analyzed the association between miR-126 and various clinicopathological parameters. In addition, cell proliferation, wound healing and cell invasion assays were conducted using RCC cells overexpressing miR-126. Potential miR-126 target genes and the signaling pathways that may be regulated by miR-126 were then examined. miR-126 expression was significantly reduced in patients with metastatic RCC compared with patients without metastasis. Consistently, overexpression of miR-126 in RCC cells significantly inhibited cell proliferation, migration and invasion in vitro compared with negative control miRNA. A luciferase reporter assay demonstrated that miR-126 targets Rho associated coiled-coil containing protein kinase 1 (ROCK1) by directly binding the 3′-untranslated region. Furthermore, western blotting identified miR-126 as an important regulator of the AKT and extracellular signal-regulated 1/2 signaling pathways. The results of the present study indicate that miR-126 inhibits RCC cell proliferation, migration and invasion by downregulating ROCK1. These findings suggest that miR-126 may be valuable as a potential target for therapeutic intervention in RCC.

miR-200c: a versatile watchdog in cancer progression, EMT, and drug resistance

MicroRNAs (miRNAs) are 20-22-nucleotide small endogenous non-coding RNAs which regulate gene expression at post-transcriptional level. In the last two decades, identification of almost 2600 miRNAs in human and their potential to be modulated opened a new avenue to target almost all hallmarks of cancer. miRNAs have been classified as tumor suppressors or oncogenes depending on the phenotype they induce, the targets they modulate, and the tissue where they function. miR-200c, an illustrious tumor suppressor, is one of the highly studied miRNAs in terms of development, stemness, proliferation, epithelial-mesenchymal transition (EMT), therapy resistance, and metastasis. In this review, we first focus on the regulation of miR-200c expression and its role in regulating EMT in a ZEB1/E-cadherin axis-dependent and ZEB1/E-cadherin axis-independent manner. We then describe the role of miR-200c in therapy resistance in terms of multidrug resistance, chemoresistance, targeted therapy resistance, and radiotherapy resistance in various cancer types. We highlight the importance of miR-200c at the intersection of EMT and chemoresistance. Furthermore, we show how miR-200c coordinates several important signaling cascades such as TGF-β signaling, PI3K/Akt signaling, Notch signaling, VEGF signaling, and NF-κB signaling. Finally, we discuss miR-200c as a potential prognostic/diagnostic biomarker in several diseases, but mainly focusing on cancer and its potential application in future therapeutics.

Knockdown of lncRNA-ATB suppresses autocrine secretion of TGF-β2 by targeting ZNF217 via miR-200c in keloid fibroblasts

Abnormally high activation of transforming growth factor-β (TGF-β) signaling has been demonstrated to be involved in the initiation and progression of keloids. However, the functional role of long non-coding RNA (lncRNA)-activated by TGF-β (lncRNA-ATB) in keloids has not been documented. Here we investigated the role of lncRNA-ATB in the autocrine secretion of TGF-β in keloid fibroblasts (KFs) and explored the underlying molecular mechanism. Using immunohistochemistry and quantitative RT-PCR analysis, we showed that lncRNA-ATB and ZNF217, a transcriptional activator of TGF-β, were overexpressed and miR-200c, which targets ZNF217, was under-expressed in keloid tissue and keloid fibroblasts. Through gain- and loss-of-function studies, we demonstrated that knockdown of lncRNA-ATB decreased autocrine secretion of TGF-β2 and ZNF217 expression but upregulated expression of miR-200c in KFs. Stable downregulation of ZNF217 expression decreased the autocrine secretion of TGF-β2. miR-200c was endogenously associated with lncRNA-ATB, and inhibition of miR-200c overcame the decrease in ZNF217 expression in KFs. Taken together, these findings indicate that lncRNA-ATB governs the autocrine secretion of TGF-β2 in KFs, at least in part, by downregulating the expression level of ZNF217 via miR-200c, suggesting a signaling axis consisting of lncRNA-ATB/miR-200c/ZNF217/TGF-β2. These findings may provide potential biomarkers and targets for novel diagnostic and therapeutic approaches for keloids.

Prognostic significance of microRNA-200c in various types of cancer: An updated meta-analysis of 34 studies

Previous studies have indicated that miR-200c is a promising cancer biomarker. However, different studies have presented conflicting results. Therefore, the aim of the present study was to perform a meta-analysis of miR-200c based on 34 relevant studies. The Materials and methods sections of papers were carefully identified using the databases PubMed, Web of Science and Embase for publications up to December 4, 2015. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were systematically calculated to investigate the association between the expression of miR-200c and cancer prognosis. The results demonstrated that elevated expression levels of miR-200c indicated significantly worse overall survival rates (HR=1.37, 95% CI: 1.01, 1.85), and a high level of miR-200c was considered an indicator of an unfavorable prognosis in patients from Europe and America (HR=1.85, 95% CI: 1.27, 2.69). Furthermore, overexpression of miR-200c was significantly associated with progression of the disease in the subgroups of tissue and blood samples (HR=0.68 and 2.45, respectively), and inferior overall survival rates for the blood subgroup were revealed (HR=2.21, 95% CI: 1.04, 4.72). In addition, miR-200c was of prognostic value in several disease subgroups. Taken together, high expression levels of miR-200c are of significant prognostic value in various human malignancies.

Prognostic significance of miR-126 in various cancers: a meta-analysis

OBJECTIVE

Recent studies have demonstrated that microRNA-126 (miR-126) might be a promising prognostic factor for cancer patients. This meta-analysis was conducted to assess the effectiveness of miR-126 as a prognostic biomarker for various cancers.

METHODS

The search of studies was performed by using PubMed and Embase until January 22, 2016. Pooled hazard ratio (HR) with 95% confidence interval (CI) for patients' survival was calculated. A fixed-effect or random-effects model was applied according to heterogeneity. The trim and fill method was used to adjust pooled HR.

RESULTS

In all 17 articles comprising of 2,437 participants were included in this meta-analysis. The results indicated that a high level of miR-126 played a favorable role in the overall survival (HR 0.70, 95% CI: 0.62-0.79, random-effects model), with a heterogeneity measure index of I (2)=63.2% (P<0.01). Subgroup analyses showed that pooled HR was more significant in patients with digestive system cancers (HR 0.70, 95% CI: 0.59-0.83, fixed-effects model) and respiratory system cancers (HR 0.71, 95% CI: 0.59-0.85, random-effects model). Owing to publication bias, HR was adjusted to 0.59 (0.463-0.752, P<0.01) by the trim and fill method.

CONCLUSION

miR-126 could be a promising biomarker for cancer prognosis prediction, especially in patients with digestive or respiratory system cancers.

MicroRNA-126 inhibits the migration and invasion of endometrial cancer cells by targeting insulin receptor substrate 1

MicroRNAs (miRs) have been demonstrated to serve important roles in the development and progression of human cancer, primarily through the direct targeting of oncogenes or tumor suppressors. It has been previously suggested that miR-126 may be associated with endometrial cancer (EC). However, the exact role of miR-126 in the migration and invasion of EC cells has not yet been studied. The present study demonstrated that the expression of miR-126 was significantly decreased in EC tissues when compared with matched normal adjacent tissues. The current study reverse transcription-quantitative polymerase chain reaction was performed in order to examine the expression level of miR-126. Wound healing and transwell assays were used to examine cell migration and invasion. A luciferase reporter assay was used to determine the targeting relationship and western blotting assay was performed to detect the protein expression. Furthermore, the overexpression of miR-126 significantly inhibited EC SKOV3 cell migration and invasion. Molecular mechanism investigation established that insulin receptor substrate 1 (IRS1) functioned as a direct miR-126 target, and its expression was negatively regulated by miR-126 at a post-transcriptional level in the SKOV3 cells. Additionally, the overexpression of IRS1 reversed the inhibitory effect of miR-126 overexpression on SKOV3 cell migration and invasion. In conclusion, the current study demonstrated that miR-126 inhibited EC cell migration and invasion, at least partially through the direct targeting of IRS1, suggesting that miR-126 may aid the treatment of EC metastasis.

Prognostic Role of MicroRNA-200c-141 Cluster in Various Human Solid Malignant Neoplasms

The miR-200 family has emerged recently as a noticeable marker for predicting cancer prognosis and tumor progression. We aimed to review the evidence of miR-200c-141 genomic cluster as prognostic biomarkers in cancers. The results suggested that high level of miR-200c had no significant impact on OS (HR = 1.14 [0.77-1.69], P = 0.501) and DFS/PFS (HR = 0.72 [0.45-1.14], P = 0.161). Stratified analyses revealed that high miR-200c expression was significantly related to poor OS in serum/plasma (HR = 2.12 [1.62-2.77], P = 0.000) but not in tissues (HR = 0.89 [0.58-1.37], P = 0.599). High miR-200c expression was significantly associated with favorable DFS/PFS in tissues (HR = 0.56 [0.43-0.73], P = 0.000) but worse DFS/PFS in serum/plasma (HR = 1.90 [1.08-3.36], P = 0.027). For miR-141, we found that high miR-141 expression predicted no significant impact on OS (HR = 1.18 [0.74-1.88], P = 0.482) but poor DFS/PFS (HR = 1.11 [1.04-1.20], P = 0.003). Similarly, subgroup analyses showed that high miR-141 expression predicted poor OS in serum/plasma (HR = 4.34 [2.30-8.21], P = 0.000) but not in tissues (HR = 1.00 [0.92-1.09], P = 0.093). High miR-141 expression was significantly associated with worse DFS/PFS in tissues (HR = 1.12 [1.04-1.20], P = 0.002) but not in serum/plasma (HR = 0.90 [0.44-1.83], P = 0.771). Our findings indicated that, compared to their tissue counterparts, the expression level of miR-200c and miR-141 in peripheral blood may be more effective for monitoring cancer prognosis. High miR-141 expression was better at predicting tumor progression than survival for malignant tumors.

Prognostic Role of MicroRNA-126 for Survival in Malignant Tumors: A Systematic Review and Meta-Analysis

Background. Increasing studies found that miR-126 expression may be associated with the prognosis of cancers. Here, we performed a meta-analysis to assess the prognostic role of miR-126 in different cancers. Methods. Eligible studies were identified by searching in PubMed, Embase, the Cochrane Library, CNKI, and Wan Fang databases up to March 2015. Pooled hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) were calculated to investigate the correlation between miR-126 and survival of cancers. Results. Thirty studies including a total of 4497 participants were enrolled in this meta-analysis. The pooled results showed that high level of miR-126 was a predictor for favorable survival of carcinomas, with pooled HR of 0.77 (95% CI 0.64–0.93) for OS, 0.64 (95%CI 0.48–0.85) for DFS, and 0.70 (95% CI 0.50–0.98) for PFS/RFS/DSS. However, high level of circulating miR-126 predicted a significantly worse OS in patients with cancer (HR = 1.65, 95% CI 1.09–2.51). Conclusions. Our results indicated that miR-126 could act as a significant biomarker in the prognosis of various cancers.

miR-126 inhibits papillary thyroid carcinoma growth by targeting LRP6

microRNA-126 (miR-126) has been reported to play tumor suppressor roles in various types of cancers. Although it has been reported that miR-126 expression is downregulated in papillary thyroid carcinoma (PTC), the precise role and underlying molecular mechanism of miR-126 in PTC remains unclear. Therefore, the aims of the present study were to investigate the role and potential mechanism of miR-126 in tumorigenicity of PTC in vivo and in vitro. We observed that the miR-126 expression level was significantly downregulated in PTC tissue and PTC cell lines, the aberrant expression of miR-126 was correlated with lymph node metastasis, tumor size and TNM stage. We also showed that restoration of miR-126 in PTC cells inhibited cell proliferation, colony formations, migration and invasion, promoted cell apoptosis and cell cycle arrest at G1 stage in vitro, as well as inhibited tumor growth and decreased tumor volume and weight in vivo. Furthermore, low-density lipoprotein receptor‑related protein 6 (LRP6), a regulator of the Wnt/β‑catenin signaling cascade, was identified as a crucial target gene of miR-126. Overexpression of miR-126 inhibited LP6 expression on mRNA and protein levels, and deactivate Wnt/β-catenin signaling pathway. These results suggested that miR-126 functions as a tumor-suppressive miRNA by targeting LRP6 regulating Wnt/β-catenin signaling pathway and represents a therapeutic target for PTC.

The microRNA-325 inhibits hepatocellular carcinoma progression by targeting high mobility group box 1

Background

MicroRNAs (miRNAs) can serve as tumor suppressors and might provide an efficient strategy for annihilating tumor cells. Nevertheless, the potential role of miR-325 in hepatocellular carcinoma (HCC) is still unknown.

Methods

Using RT-PCR, immunoblots invasion assays and bioinformatics strategies, we investigated the potential role of miR-325 in HCC.

Results

We showed that miR-325 was decreased and HMGB1 was increased in 99 patients with hepatocellular carcinoma. MiR-325 inhibition promoted cell invasion and proliferation, while miR-325 upregulation inhibited cell invasion and proliferation by using transwell and CCK8 assays. We further showed that HMGB1 might be a direct target of miR-325 and is negatively regulated by miR-325. Down-regulation of miR-325 predicts poor prognosis for HCC patients.

Conclusions

These findings implied that miR-325 regulates cell invasion and proliferation via targeting HMGB1 and may be a potential prognostic marker for HCC.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4655707031717989

Tissue microRNA-126 expression level predicts outcome in human osteosarcoma

Background

MicroRNA-126 has been found to be consistently under-expressed in osteosarcoma tissues and cell lines compared with normal bone tissues and normal osteoblast cells, respectively. The purpose of the present study was to detect the expression levels of miR-126 in osteosarcoma patients and to further investigate the clinicopathological, and prognostic value of miR-126.

Methods

We recruited 122 patients with osteosarcomas from the Department of Orthopedic Surgery, Yantaishan Hospital between May 2008 and April 2013. The expression level of miR-126 was determined by qRT-PCR. Associations between miR-126 expression and various clinicopathological characteristics were analyzed using the χ² test. Survival rate was determined with Kaplan-Meier and statistically analyzed with the log-rank method between groups. Survival data were evaluated through multivariate Cox regression analysis.

Results

miR-126 expression was significantly decreased in osteosarcoma tissues compared to adjacent normal bone tissues (2.421 ± 1.250 vs. 6.212 ± 1.843, P = 0.001). We found that low miR-126 expression had significant association with advanced TNM stage (P <0.001), distant metastasis (P <0.001), and higher tumor grade (P = 0.001). Kaplan-Meier survival analysis showed that the miR-126 low-expression group had significantly shorter overall survival time than those with high-expression (log-rank test, P = 0.008). Furthermore, multivariate Cox proportional hazards model analysis showed that miR-126 expression was independently associated with overall survival of patients with osteosarcoma (HR = 3.102, 95 % CI: 1.113–9.023, P = 0.018).

Conclusions

This is the first study revealing that miR-126 down-expression may be related to the prediction of poor prognosis for osteosarcoma patients, suggesting that miR-126 may serve as a prognostic marker for the optimization of clinical treatments.

Prognostic Value and Clinicopathology Significance of MicroRNA-200c Expression in Cancer: A Meta-Analysis

MiR-200c has been shown to be related to cancer formation and progression. However, the prognostic and clinicopathologic significance of miR-200c expression in cancer remain inconclusive. We carried out this systematic review and meta-analysis to investigate the prognostic value of miR-200c expression in cancer. Pooled hazard ratios (HRs) of miR-200c for overall survival (OS) and progression-free survival (PFS) were calculated to measure the effective value of miR-200c expression on prognosis. The association between miR-200c expression and clinical significance was measured by odds ratios (ORs). Twenty-three studies were included in our meta-analysis. We found that miR-200c was not significantly correlated with OS (HR = 1.41, 95%Cl: 0.95-2.10; P = 0.09) and PFS (HR = 1.12, 95%Cl: 0.68-1.84; P = 0.67) in cancer. In our subgroup analysis, higher expression of miR-200c was significantly associated with poor OS in blood (HR = 2.10, 95%CI: 1.52-2.90, P<0.00001). Moreover, in clinicopathology analysis, miR-200c expression in blood was significantly associated with TNM stage, lymph node metastasis and distant metastasis. MiR-200c may have the potential to become a new blood biomarker to monitor cancer prognosis and progression.

miR-15b regulates cisplatin resistance and metastasis by targeting PEBP4 in human lung adenocarcinoma cells

MicroRNAs (miRNAs) have been identified as important posttranscriptional regulators involved in various biological and pathological processes of cells, but their association with tumor chemoresistance has not been fully understood. We detected miR-15b expression in two lung adenocarcinoma cell lines, A549 and A549/CDDP, and then investigated the effects of miR-15b on the metastasis and the chemosensitivity of cancer cells, using both gain- and loss-of-function studies. The correlation between miR-15b level and chemoresistance was further investigated in clinical lung adenocarcinoma specimens. miR-15b was significantly upregulated in cisplatin-resistant lung adenocarcinoma A549/CDDP cells compared with parental A549 cells. miR-15b regulates epithelial-mesenchymal transition (EMT) and cisplatin resistance in vitro and modulates response of lung adenocarcinoma cells to cisplatin in vivo. Further studies identified phosphatidylethanolamine-binding protein 4 (PEBP4) as a direct and functional target of miR-15b. Small-interfering RNA-mediated PEBP4 knockdown revealed similar effects as that of ectopic miR-15b expression, whereas overexpression of PEBP4 attenuated the function of miR-15b in lung adenocarcinoma cells. Increased miR-15b expression was also detected in tumor tissues sampled from lung adenocarcinoma patients treated with cisplatin-based chemotherapy and was proved to be correlated with low expression of PEBP4, decreased sensitivity to cisplatin and poor prognosis. Our results suggest that upregulation of miR-15b could suppress PEBP4 expression and in turn contribute to chemoresistance of lung adenocarcinoma cells to cisplatin.

Expression of MicroRNA-325-3p and its potential functions by targeting HMGB1 in non-small cell lung cancer

MicroRNAs (miRNAs) can function as tumor suppressors and might provide an efficient strategy for annihilating cancer. Nevertheless, the potential role of miR-325-3p in NSCLC is still unknown. Here, we showed that miR-325-3p was decreased and HMGB1 was increased in 107 NSCLC patients. MiR-325-3p inhibition promoted cell invasion and proliferation, while miR-325-3p upregulation inhibited cell invasion and proliferation by using transwell and CCK8 assays. Using a bioinformatics method, we further showed that HMGB1 might be a direct target of miR-325-3p and is negatively regulated by miR-325-3p. Down-regulation of miR-325-3p predicts poor prognosis for NSCLC patients. These findings implied that miR-325-3p regulates cell invasion and proliferation via targeting HMGB1 and may be a potential prognostic marker for NSCLC.

The Role of microRNAs in Mitochondria: Small Players Acting Wide

MicroRNAs (miRNAs) are short, single-stranded, non-coding RNA molecules that act as post-transcriptional gene regulators. They can inhibit target protein-coding genes, through repressing messenger RNA (mRNA) translation or promoting their degradation. miRNAs were initially found to be originated from nuclear genome and exported to cytosol; where they exerted most of their actions. More recently, miRNAs were found to be present specifically in mitochondria; even originated there from mitochondrial DNA, regulating in a direct manner genes coding for mitochondrial proteins, and consequently mitochondrial function. Since miRNAs are recognized as major players in several biological processes, they are being considered as a key to better understand, explain, and probably prevent/cure not only the pathogenesis of multifactorial diseases but also mitochondrial dysfunction and associated diseases. Here we review some of the molecular mechanisms purported for miRNA actions in several biological processes, particularly the miRNAs acting in mitochondria or in mitochondria-related mechanisms.