High expression of miR-21 and miR-155 predicts recurrence and unfavourable survival in non-small cell lung cancer. Eur J Cancer. 2013;49:604-615. [PMID: 23099007 DOI: 10.1016/j.ejca.2012.09.031]

lncRNA HOXA11-AS Promotes Proliferation and Migration via Sponging miR-155 in Hypopharyngeal Squamous Cell Carcinoma

Hypopharyngeal squamous cell carcinoma (HSCC) remains one of the most lethal malignancies in the head and neck. Long noncoding RNA (lncRNA) HOXA11-AS is proven to function as an oncogene and a therapeutic target in various tumors. Our previous study and others have demonstrated that HOXA11-AS is one of the most upregulated lncRNAs in HSCC. However, the role of HOXA11-AS in HSCC has not yet been identified. The current study demonstrated that the expression of HOXA11-AS was significantly upregulated in HSCC tumors and was positively associated with lymph node metastasis. Moreover, functional experiments revealed that HOXA11-AS knockdown suppressed the proliferation and migration potential in FaDu cells. Furthermore, luciferase reporter gene assay combined with cellular functional experiments demonstrated that HOXA11-AS functioned as a molecular sponge for miR-155, and inhibition of miR-155 attenuated the suppressive effect of HOXA11-AS knockdown on the aggressive phenotype in HSCC. This study identifies a tumor-promoting role of HOXA11-AS in HSCC and suggests HOXA11-AS might be a potential diagnostic and therapeutic target for HSCC.

Clinical significance of aberrant microRNAs expression in predicting disease relapse/refractoriness to treatment in diffuse large B-cell lymphoma: A meta-analysis

The clinical significance of aberrantly expressed microRNAs in predicting treatment response to chemotherapy in diffuse large B-cell lymphoma patients (DLBCL) remains uncertain. Feasibility of microRNA testing to predict treatment outcome was evaluated. Twenty-two types of aberrantly expressed microRNAs were associated with poor treatment response; pooled hazard ratio (HR) was 2.14 [95%CI:1.78-2.57, P < 0.00001]. DLBCL patients with aberrant expression of miR-155, miR-17/92 clusters, miR-21, miR-224, or miR-146b-5p had a higher risk of treatment resistance or shorter period of disease relapse/progression free survival, with HR = 2.71 (95%CI:1.66-4.42, P < 0.0001), HR = 2.70 (95%CI:1.50-4.85, P = 0.0010), HR = 2.20 (95%CI:1.31-3.69, P = 0.003), HR = 2.07 (95%CI:1.50-2.86, P < 0.00001), HR = 2.26 (95%CI:1.40-3.65, P = 0.0009), respectively. The association between aberrant expression of microRNAs and treatment response appears to be stronger in formalin-fixed-paraffin-embedded tissue (HR = 2.41, 95%CI:1.79-3.25, P < 0.00001) than in fresh-frozen samples (HR = 1.94, 95%CI: 1.22-3.08, P = 0.005) and peripheral blood samples (HR = 1.94, 95%CI:1.53-2.46, P < 0.00001). Mir-155, miR-17/92 clusters, miR-21, miR-224, and mir-146b-5p have value in predicting treatment response to chemotherapy in DLBCL.

MiR-4766-5p Inhibits The Development And Progression Of Gastric Cancer By Targeting NKAP

Purpose

It is widely known that some specific microRNAs can regulate the expressions of genes in gastric cancer cells at the post-transcriptional level. Previous studies have identified that miRNA-4766-5p was involved in tumor cell proliferation and can be an independent prognostic indicator for malignant pleural mesothelioma. However, the mechanism underlying gastric cancer via the miRNA-4766-5p pathway remains to be blank.

Methods

We investigated the expression of miR-4766-5p in gastric cancer tissues and cells through qRT-PCR. We used RNAi to change the expressions of miR-4766-5p in gastric cancer cell lines, AGS and MKN45. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect the mRNA expression of miR-4766-5p. We identified cell proliferation by CCK8 and clone formation assays. We analyzed the cell apoptosis and cycle through flow cytometry. At last, we used a dual-luciferase reporter assay to illustrate the interaction between miR-4766-5p and NKAP and used Western blot to determine the protein expression of signaling pathways.

Results

We found that 1) miR-4766-5p was down-regulated in gastric cancer tissues and cells lines; 2) miR-4766-5p inhibited cell proliferation of gastric cancer cell lines significantly; 3) miR-4766-5p significantly inhibited cell migration and invasion of gastric cancer cells; 4) miR-4766-5p induced gastric cancer cell apoptosis. 5) NKAP was a direct target gene of miR-4766-5p; and 6) miR-4766-5p induced inactivation of AKT/mTOR pathway.

Conclusion

The above results indicate that miR-4766-5p suppressed the proliferation and metastasis of gastric cancer cells through targeting NKAP. Our findings could probably contribute to the diagnostics and prognostics of gastric cancer through new methodologies.

MiR-1827 functions as a tumor suppressor in lung adenocarcinoma by targeting MYC and FAM83F

The bioactivity of microRNA-1827 (miR-1827) in lung adenocarcinoma cells would be explored. The expression level of gene and miR-1827 in 76 pairs of lung adenocarcinoma tissues and adjacent counterparts were analyzed by a quantitative real-time polymerase chain reaction. Primary lung adenocarcinoma cells were derived from patients' tissues. These cells were treated with miR-1827 agomir to mimic the upregulation of endogenous miR-1827. The malignant degree of lung adenocarcinoma cells in vitro was evaluated by cell proliferation, colony formation, transwell invasion, and apoptosis assays. Western blot analysis was used to observe the transition of lung adenocarcinoma cells from epithelial-to-mesenchymal. Target genes of miR-1827 were predicted by bioinformatics analysis. In addition, the interaction between miR-1827 and candidate messenger RNAs was verified by dual-luciferase reporter assay and AGO2-RNA immunoprecipitation. Besides, the effect of miR-1827 on tumors was verified by in vivo experiments. Transient gene overexpression was achieved by plasmids transfection. In this study, we found that the expression of miR-1827 was downregulated in lung adenocarcinoma, and its low expression was significantly correlated with the progression of lung adenocarcinoma and poor prognosis of patients. miR-1827 overexpression remarkably reduced the malignancy of primary lung adenocarcinoma cells in vitro. MYC and FAM83F were identified as two targeted genes of miR-1827 in lung adenocarcinoma cells. The levels of these two genes were upregulated in lung adenocarcinoma, and their high expression was significantly associated with the progression of lung adenocarcinoma and poor prognosis of patients. Overexpression of MYC or FAM83F attenuated the effects of miR-1827 on primary lung adenocarcinoma cells in vitro. In addition, in vivo experiments showed that miR-1827 inhibited tumor growth by reducing the levels of MYC and FAM83F. In conclusion, miR-1827 might repress the development of lung adenocarcinoma by targeting oncogenic genes MYC and FAM83F.

Electrochemical-based biosensors for microRNA detection: Nanotechnology comes into view

Nanotechnology plays an undeniable significant role in medical sciences, particularly in the field of biomedicine. Development of several diagnostic procedures in medicine has been possible through the beneficial application of nano-materials, among which electrochemical nano-biosensors can be mentioned. They can be employed to quantify various clinical biomarkers in detection, evaluation, and follow up stages of the illnesses. MicroRNAs, a group of regulatory short RNA fragments, added a new dimension to the management and diagnosis of several diseases. Mature miRNAs are single-stranded RNA molecules approximately 22 nucleotides in length, which regulate a vast range of biological functions from cellular proliferation and death to cancer development and progression. Recently, diagnostic value of miRNAs in various diseases has been demonstrated. There are many traditional methods for detection of miRNAs including northern blotting, quantitative real time PCR (qRT-PCR), microarray technology, nanotechnology-based approaches, and molecular biology tools including miRNA biosensors. In comparison with other techniques, electrochemical nucleic acid biosensor methods exhibit many interesting features, and could play an important role in the future nucleic acid analysis. This review paper provides an overview of some different types of nanotechnology-based biosensors for detection of miRNAs.

Tissue-specific and exosomal miRNAs in lung cancer radiotherapy: from regulatory mechanisms to clinical implications

Lung cancer is the most prevalent and deadly malignancy. Radiotherapy is a major treatment modality for lung cancer. Nevertheless, radioresistance poses a daunting challenge that largely limits the efficacy of radiotherapy. There is a pressing need for deciphering molecular mechanisms underlying radioresistance and elucidating novel therapeutic targets for individualized radiotherapy. MicroRNAs are categorized as small noncoding RNAs that modulate target-gene expression posttranscriptionally and are implicated in carcinogenesis and cancer resistance to treatment. Overwhelming evidence has unraveled that tissue-specific miRNAs are essential for regulation of the radiosensitivity in lung cancer cells through a complex interaction with multiple biological processes and radiation-induced pathways. Moreover, exosome-derived miRNAs are a novel horizon in lung cancer treatment in which exosomal miRNAs act as potential diagnostic and therapeutic biomarkers of radiotherapy. In the present review, we discuss the mediation of key biological processes and signaling pathways by tissue-specific miRNAs in lung cancer radiotherapy. Additionally, we provide new insight into the potential significance of exosomal miRNAs in radiation response. Lastly, we highlight miRNAs as promising predictors and therapeutic targets to tailor personalized lung cancer radiotherapy.

High expression of miR-155 and miR-21 in the recurrence or metastasis of non-small cell lung cancer

High expression of miR-155 and miR-21 in the recurrence or metastasis of non-small cell lung cancer (NSCLC) was investigated. Retrospective analysis on the clinical information of 180 patients with NSCLC was carried out. The patients were admitted to Daqing Oil Field General Hospital from February 2012 to March 2015 and they were the research group. Moreover, the physical examination information of 88 normal medical examinees were selected at the same period of time as the control group. In the research group, 68 patients diagnosed with NSCLC were the newly diagnosed group and 112 cases of recurrence or metastasis of NSCLC were the recurrence group. The quantitative real-time polymerase chain reaction was used to detect the expression levels of serum miR-115 and miR-21. In addition, the expression levels between miR-155 and miR-21 and the relationship between the recurrence rate and metastasis of NSCLC were analyzed. The impact on the prognosis of patients were also analyzed. The expression levels of serum miR-155 and miR-21 were higher in the research group than those in the control group (P<0.05). The expression levels of serum miR-155 and miR-21 were higher in the recurrence group than those in the newly diagnosed group (P<0.05). We followed up the patients in the research group for 36 months, the median survival time and mortality rate in the recurrence group was higher than that of in the newly diagnosed group (χ²=9.705, P<0.01). In conclusion, miR-155 and miR-21 were highly expressed in the serum of patients, however, the recurrence and metastasis of NSCLC were even higher. The highly expressed levels of miR-155 and miR-21 were associated with the recurrence and metastasis in NSCLC patients, affecting the prognosis of patients.

Prognostic value of IGF-1R in lung cancer: A PRISMA-compliant meta-analysis

BACKGROUND

Insulin-like growth factor receptor 1 (IGF-1R) is a key player in a wide array of pathological processes, while the prognostic role of IGF-1R in lung cancer remains controversial.

METHODS

We conducted a meta-analysis to evaluate the prognostic value of IGF-1R in lung cancer. We searched for recent studies on the expression of IGF-1R and extracted prognostic lung cancer data from the articles.

RESULTS

Eventually, 22 studies with 3859 patients were analyzed in our meta-analysis. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were used to quantify the ability of IGF-1R to predict survival. The results indicated that IGF-1R positive expression was associated with an unfavorable disease-free survival (DFS) in non-small cell lung cancer (NSCLC) patients on univariate analysis (HR = 1.24, 95% CI: 1.00-1.55, P = .054) and multivariate analysis (HR = 1.49, 95% CI: 1.01-2.21, P = .045), but there was no significant difference in the relationship between IGF-1R positive expression and overall survival (OS) on univariate analysis (HR = 1.04, 95% CI: 0.86-1.25, P = .712) and multivariate analysis (HR = 0.89, 95% CI: 0.57-1.39, P = .602). IGF-1R mRNA expression related to OS was obtained in 2 studies, with the pooled HR being 1.663 (95% CI: 1.071-2.583, P = .024). For IGF-1R expression and small cell lung cancer (SCLC), the conclusion was not statistically significant, with the pooled HR being 1.22 (95% CI: 0.66-2.27, P = .524).

CONCLUSIONS

Our results indicate that high expression of IGF-1R predicts poor DFS in NSCLC, yet it does not predict poor OS in NSCLC and SCLC. IGF-1R may be a useful predictor of outcomes in patients with NSCLC.

The Roles of MicroRNA in Lung Cancer

Lung cancer is the most devastating malignancy in the world. Beyond genetic research, epigenomic studies—especially investigations of microRNAs—have grown rapidly in quantity and quality in the past decade. This has enriched our understanding about basic cancer biology and lit up the opportunities for potential therapeutic development. In this review, we summarize the involvement of microRNAs in lung cancer carcinogenesis and behavior, by illustrating the relationship to each cancer hallmark capability, and in addition, we briefly describe the clinical applications of microRNAs in lung cancer diagnosis and prognosis. Finally, we discuss the potential therapeutic use of microRNAs in lung cancer.

Clinical Implication of MicroRNAs in Molecular Pathology: An Update for 2018

MicroRNAs (miRNAs) are poised to provide diagnostic, prognostic, and therapeutic targets for several diseases including malignancies for precision medicine applications. The miRNAs have immense potential in the clinical arena because they can be detected in the blood, serum, tissues (fresh and formalin-fixed paraffin-embedded), and fine-needle aspirate specimens. The most attractive feature of miRNA-based therapy is that a single miRNA could be useful for targeting multiple genes that are deregulated in cancers, which can be further investigated through systems biology and network analysis that may provide cancer-specific personalized therapy.

Extracellular vesicles secreted by hypoxia pre-challenged mesenchymal stem cells promote non-small cell lung cancer cell growth and mobility as well as macrophage M2 polarization via miR-21-5p delivery

Objective

To investigate the lung cancer-promoting mechanism of mesenchymal stem cell-secreted extracellular vesicles (MSC-EV).

Methods

EV were isolated from culture media of human bone marrow-derived MSCs that were pre-challenged with or without hypoxia (referred to as H-EV and N-EV, respectively). After treatment with N-EV or H-EV, A549 and H23 cell proliferation, apoptosis, trans-well invasion and epithelial-to-mesenchymal transition (EMT) were examined. Polarization of human primary monocytes-derived macrophages with or without N-EV or H-EV induction were analyzed by flow cytometry and ELISA. PTEN, PDCD4 or RECK gene was overexpressed in A549 cells, while miR-21-5p was knocked down in MSCs, A549 or H23 lung cancer cells or primary monocytes by miR-21-5p inhibitor transfection. Protein level of PTEN, PDCD4, RECK, AKT or STAT3 as well as phosphorylation level of AKT or STAT3 protein were assayed by western blot. Tumorigenicity of A549 and H23 cells with or without MSC-EV co-injection was assayed on immunocompromised mice. The xenograft tumor were examined for cell proliferation, angiogenesis, apoptosis and intra-tumoral M1/M2 macrophage polarization.

Results

Comparing to N-EV, H-EV treatment significantly increased A549 and H23 cell proliferation, survival, invasiveness and EMT as well as macrophage M2 polarization. MiR-21-5p knocked down significantly abrogated the cancer-promoting and macrophage M2 polarizing effects of H-EV treatment. H-EV treatment downregulated PTEN, PDCD4 and RECK gene expression largely through miR-21-5p. Overexpressing PTEN, PDCD4 and RECK in A549 cells significantly reduced the miR-21-5p-mediated anti-apoptotic and pro-metastatic effect of H-EV, while overexpressing PTEN in monocytes significantly reduced macrophage M2 polarization after induction with the presence of H-EV. H-EV co-injection significantly increased tumor growth, cancer cell proliferation, intra-tumoral angiogenesis and M2 polarization of macrophages in vivo partially through miR-21-5p.

Conclusions

Increased miR-21-5p delivery by MSC-EV after hypoxia pre-challenge can promote lung cancer development by reducing apoptosis and promoting macrophage M2 polarization.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1027-0) contains supplementary material, which is available to authorized users.

Idiopathic Pulmonary Fibrosis and Lung Cancer: Mechanisms and Molecular Targets

Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pulmonary disease with a median survival of 2–4 years after diagnosis. A significant number of IPF patients have risk factors, such as a history of smoking or concomitant emphysema, both of which can predispose the patient to lung cancer (LC) (mostly non-small cell lung cancer (NSCLC)). In fact, IPF itself increases the risk of LC development by 7% to 20%. In this regard, there are multiple common genetic, molecular, and cellular processes that connect lung fibrosis with LC, such as myofibroblast/mesenchymal transition, myofibroblast activation and uncontrolled proliferation, endoplasmic reticulum stress, alterations of growth factors expression, oxidative stress, and large genetic and epigenetic variations that can predispose the patient to develop IPF and LC. The current approved IPF therapies, pirfenidone and nintedanib, are also active in LC. In fact, nintedanib is approved as a second line treatment in NSCLC, and pirfenidone has shown anti-neoplastic effects in preclinical studies. In this review, we focus on the current knowledge on the mechanisms implicated in the development of LC in patients with IPF as well as in current IPF and LC-IPF candidate therapies based on novel molecular advances.

Prognostic Role of MicroRNAs in Human Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Background

MicroRNAs (miRNAs) have been found to play an important role in the development and outcomes for multiple human cancers. Their role as a prognostic biomarker in non-small-cell lung cancer (NSCLC) remains unclear. This meta-analysis aims to clarify the role of various miRNAs in the survival of NSCLC patients.

Materials and Methods

All studies were identified through medical database search engines. A meta-analysis was conducted to assess the correlation between miRNAs expressions and overall survival among those NSCLC studies. Relevant data were extracted from each eligible study regarding baseline characteristics and key statistics such as hazard ratio (HR), 95% confidence interval (CI), and P value, which were utilized to calculate a pooled effect size.

Result

Thirty-two studies were included in the meta-analysis. Using a random effect model, the combined HR and 95% CI for overall survival (OS) was calculated as 1.59 (1.39–1.82), predicting a poor overall survival. Five miRNAs (miR-21, miR-155, miR-let-7, miR-148a, and miR-148b) were found to be of significance for predicting OS in at least two studies, hence, selected for subgroup analysis. Subgroup analysis disclosed that elevated levels of miR-21 and miR-155 in both cancer tissue and blood samples were associated with worse OS. Compared to American studies (I-squared: <0.001% and P value: 0.94), Asian and European studies exhibited greater heterogeneity in miRNA expression and relationship to OS (I-squared, P values were approximately 78.85%, <0.001 and 61.28%, 0.006, respectively). These subgroup analyses also highlighted that elevated expression of miR-21 and miR-155 and low levels of expression of miR-148a, miR-148b, and miR-let-7 were associated with poor prognosis in NSCLC.

Conclusion

miR-21, miR-155, miR-148a, miR-148b, and miR-let-7 are consistently up- or downregulated in NSCLC and are associated with poor OS. These miRNAs show potential as useful prognostic biomarkers in the diagnosis, treatment, and follow-up of NSCLC.

Establishment and validation of a 7-microRNA prognostic signature for non-small cell lung cancer

Purpose

A series of microRNAs (miRNAs) have been identified as associated with the survival of patients with non-small-cell lung cancer (NSCLC). The aim of the present study was to explore whether combination of these experimentally validated individual miRNA biomarkers could be used to further increase their prognostic power in NSCLC.

Patients and methods

Based on previously validated NSCLC prognostic miRNAs, gene signatures that could discriminate high-risk subgroups with poor clinical outcome in four NSCLC miRNA expression datasets (GSE13937, GSE16025, The Cancer Genome Atlas Lung Adenocarcinoma, and TCGA lung squamous cell carcinoma) were developed using the SurvMicro tool. The potential of the miRNA signature established was validated by quantitative real-time PCR analysis of clinical NSCLC samples, and its prognostic power evaluated using the survivalROC method.

Results

We developed two miRNA signatures with prognostic significance for NSCLC, comprising 12- and 7-miRNAs. The 7-miRNA signature (miR-148b, miR-365, miR-32, miR-375, miR-21, miR-125b, and miR-155) was a subset of a 12-miRNA set that retained prognostic power across NSCLC cohorts. Compared with previously established miRNA signatures, our 7-miRNA signature has similar potential, while comprising fewer miRNA components. The prognostic ability of the 7-miRNA signature was validated experimentally in an independent NSCLC cohort using real-time PCR (HR=3.4847, 95% CI=1.3693–8.8680, P=0.0092), and this signature, combined with tumor pathological stage, had superior prognostic ability compared with tumor stage alone.

Conclusion

Our data indicate that the established 7-miRNA signature is simple, robust, and may have greater clinical prognostic utility for patients with NSCLC.

MicroRNA in lung cancer: role, mechanisms, pathways and therapeutic relevance

Lung cancer is the cardinal cause of cancer-related deaths with restricted recourse of therapy throughout the world. Clinical success of therapies is not very promising due to - late diagnosis, limited therapeutic tools, relapse and the development of drug resistance. Recently, small ∼20-24 nucleotides molecules called microRNAs (miRNAs) have come into the limelight as they play outstanding role in the process of tumorigenesis by regulating cell cycle, metastasis, angiogenesis, metabolism and apoptosis. miRNAs essentially regulate gene expression via post-transcriptional regulation of mRNA. Nevertheless, few studies have conceded the role of miRNAs in activation of gene expression. A large body of data generated by numerous studies is suggestive of their tumor-suppressing, oncogenic, diagnostic and prognostic biomarker roles in lung cancer. They have also been implicated in regulating cancer cell metabolism and resistance or sensitivity towards chemotherapy and radiotherapy. Further, miRNAs have also been convoluted in regulation of immune checkpoints - Programmed death 1 (PD-1) and its ligand (PD-L1). These molecules play a significant role in tumor immune escape leading to the generation of a microenvironment favouring tumor growth and progression. Therefore, it is imperative to explore the expression of miRNA and understand its relevance in lung cancer and development of anti-cancer strategies (anti - miRs, miR mimics and micro RNA sponges). In view of the above, the role of miRNA in lung cancer has been dissected and the associated mechanisms and pathways are discussed in this review.

MicroRNA-21: A promising biomarker for the prognosis and diagnosis of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common subtype of lung cancer worldwide. The high mortality rate of NSCLC is due to a limited number of diagnosis being made at an early stage of disease. Therefore, the development of a novel biological marker for the diagnosis and prognosis prediction of NSCLC remains urgent. Current literature shows that microRNA-21 (miRNA-21/miR-21), as an oncogenic miRNA, is involved in the growth, metastasis and apoptosis of NSCLC cells through its control of various target molecules and signaling pathways. Notably, a growing body of evidence further shows that miR-21 is closely associated with the prognosis prediction, recurrence and diagnosis of cancer patients, indicating that miR-21 may be a novel promising biomarker for the diagnosis and prognosis prediction of NSCLC. The present review aimed to provide a summary of recent findings on the associated progression toward finding a novel biomarker for NSCLC.

Liquid Biopsy for Advanced Non-Small Cell Lung Cancer (NSCLC): A Statement Paper from the IASLC

The isolation and analysis of circulating cell-free tumor DNA in plasma is a powerful tool with considerable potential to improve clinical outcomes across multiple cancer types, including NSCLC. Assays of this nature that use blood as opposed to tumor samples are frequently referred to as liquid biopsies. An increasing number of innovative platforms have been recently developed that improve not only the fidelity of the molecular analysis but also the number of tests performed on a single specimen. Circulating tumor DNA assays for detection of both EGFR sensitizing and resistance mutations have already entered clinical practice and many other molecular tests - such as detection of resistance mutations for Anaplastic Lymphoma Kinase (ALK) receptor tyrosine kinase rearrangements - are likely to do so in the near future. Due to an abundance of new evidence, an appraisal was warranted to review strengths and weaknesses, to describe what is already in clinical practice and what has yet to be implemented, and to highlight areas in need of further investigation. A multidisciplinary panel of experts in the field of thoracic oncology with interest and expertise in liquid biopsy and molecular pathology was convened by the International Association for the Study of Lung Cancer to evaluate current available evidence with the aim of producing a set of recommendations for the use of liquid biopsy for molecular analysis in guiding the clinical management of advanced NSCLC patients as well as identifying unmet needs. In summary, the panel concluded that liquid biopsy approaches have significant potential to improve patient care, and immediate implementation in the clinic is justified in a number of therapeutic settings relevant to NSCLC.

ELLPMDA: Ensemble learning and link prediction for miRNA-disease association prediction

Recently, accumulating evidences have indicated miRNAs play critical roles in the progression and development of various human complex diseases, which pointed out that identifying miRNA-disease association could enable us to understand diseases at miRNA level. Thus, revealing more and more potential miRNA-disease associations is a vital topic in biomedical domain. However, it will be extremely expensive and time-consuming if we examine all the possible miRNA-disease pairs. Therefore, more accurate and efficient methods are being highly requested to detect potential miRNA-disease associations. In this study, we developed a computational model of Ensemble Learning and Link Prediction for miRNA-Disease Association prediction (ELLPMDA) to achieve this goal. By integrating miRNA functional similarity, disease semantic similarity, miRNA-disease association and Gaussian profile kernel similarity for miRNAs and diseases, we constructed a similarity network and utilized ensemble learning to combine rank results given by three classic similarity-based algorithms. To evaluate the performance of ELLPMDA, we exploited global and local Leave-One-Out Cross Validation (LOOCV), 5-fold Cross Validation (CV) and three kinds of case studies. As a result, the AUCs of ELLPMDA is 0.9181, 0.8181 and 0.9193+/-0.0002 in global LOOCV, local LOOCV and 5-fold CV, respectively, which significantly exceed almost all the previous methods. Moreover, in three distinct kinds of case studies for Kidney Neoplasms, Lymphoma, Prostate Neoplasms, Colon Neoplasms and Esophageal Neoplasms, 88%, 92%, 86%, 98% and 98% out of the top 50 predicted miRNAs has been confirmed, respectively. Besides, ELLPMDA is based on global similarity measure and applicable to new diseases without any known related miRNAs.

Identification of the tumor‑suppressive function of circular RNA FOXO3 in non‑small cell lung cancer through sponging miR‑155

Circular RNAs (circRNAs) are a class of endogenous noncoding RNAs that have been demonstrated to be potential regulators in the development and progression of various types of human cancer. However, little is known about their roles in cancer initiation and progression, particular in non-small cell lung cancer (NSCLC). In the present study, the expression level of circRNA-forkhead box O3 class (FOXO3) in NSCLC specimens was determined and its functional role was investigated in NSCLC cells. By performing Taq-man based RT-qPCR, it was identified that circRNA-FOXO3 was downregulated in NSCLC tissues and cell lines. Receiver operating curve analysis indicated that circRNA-FOXO3 had a relatively higher diagnostic accuracy. The functional relevance was further examined by biological assays. circRNA-FOXO3 significantly promoted the ability of cell proliferation, migration and invasion of NSCLC cells. The linear isomer of circRNA-FOXO3, FOXO3 gene, was identified as a downstream target. RNA immunoprecipitation indicated that circRNA-FOXO3 sequestering miR-155, which further promoted linear FOXO3 expression. In addition, gain and loss functional assays indicated that circRNA-FOXO3 served an anti-oncogenic role through sequestering miR-155 and enhancing FOXO3 expression. These results suggest that circRNA-FOXO3 is a tumor-suppressor in NSCLC and may serve as a promising therapeutic target. Therefore, restoration of circRNA-FOXO3 expression could be a future approach to develop a novel treatment strategy.

MiR-21 and MiR-155 promote non-small cell lung cancer progression by downregulating SOCS1, SOCS6, and PTEN

Lung cancer remains the leading cause of cancer-associated death worldwide. MiR-21 and miR-155 are the most amplified miRNAs in non-small cell lung carcinoma (NSCLC), and are critical promoters of NSCLC progression. However, it remains unclear how miR-21 and miR-155 induce cancer progression, and whether these miRNAs share common targets, such as tumor suppressor genes required to prevent NSCLC. Here we report that miR-21 and miR-155 levels are elevated in NSCLC and are proportional to the progression of the disease. In addition, miR-21 and miR-155 share nearly 30% of their predicted target genes, including SOCS1, SOCS6, and PTEN, three tumor suppressor genes often silenced in NSCLC. Consequently, antagonizing miR-21, miR-155 or both potently inhibited tumor progression in xenografted animal models of NSCLC. Treatment with miR-21 and miR-155 inhibitors in combination was always more effective against NSCLC than treatment with a single inhibitor. Furthermore, levels of miR-21 and miR-155 expression correlated inversely with overall and disease-free survival of NSCLC patients. Our findings reveal that miR-21 and miR-155 promote the development of NSCLC, in part by downregulating SOCS1, SOCS6, and PTEN. Combined inhibition of miR-21 and miR-155 could improve the treatment of NSCLC.

Targeted gene therapy of the HSV-TK/hIL-12 fusion gene controlled by the hSLPI gene promoter of human non-small cell lung cancer in vitro

The incidence of lung cancer and lung cancer-associated mortality have markedly increased worldwide, and gene-targeted therapy has emerged as a promising treatment strategy. The present study aimed to explore the targeted antitumor effect of the herpes simplex virus-thymidine kinase/human interleukin-12 (HSV-TK/hIL-12) fusion gene regulated by the human secretory leukocyte protease inhibitor (hSLPI) promoter of human non-small cell lung cancer (hNSCLC). There were four recombinant eukaryotic expression vectors: pcDNA3.1-CMV-TK, pcDNA3.1-CMV-TK/hIL-12, pcDNA3.1-phSLP-TK and pcDNA3.1-phSLP-TK/hIL-12. These were constructed and transfected into the A549, SPC-A1 and HepG2 cell lines in vitro. The expression of the HSV-TK/hIL-12 fusion gene was detected with reverse transcription-polymerase chain reaction (RT-PCR), and the content of hIL-12 was measured using an ELISA. The antitumor effect of the fusion gene on the A549, SPC-A1 and HepG2 cell lines was determined using an MTT assay. Analysis of the experimental data demonstrated that genes regulated by the cytomegalovirus promoter were expressed at the same level in three different tumor cell lines. Genes regulated by the hSLPI promoter were expressed in the A549 and SPC-A1 cell lines, but not in the HepG2 cell line. Coincidentally, the hIL-12 expression levels were similar to those observed in previous RT-PCR findings. In the Pcmv-TK/Pcmv-TK-hIL-12 group for all three cell lines, as well as in the PSLPI-TK/PSLPI-TK-hIL-12 group for the A549 and SPC-A1 cell lines, the cell survival rate declined significantly and the fusion gene transfection group indicated a lower cell survival rate, when compared with single gene transfection group. The present study indicated that the fusion gene regulated by the hSLPI promoter had a targeted antitumor effect on hNSCLC, and that the combined suicide gene and immune gene therapy had a stronger antitumor effect, compared with single gene therapy.

Assessing the clinical value of microRNAs in formalin-fixed paraffin-embedded liposarcoma tissues: Overexpressed miR-155 is an indicator of poor prognosis

Liposarcoma (LPS) is a malignancy with extreme heterogeneity and thus optimization towards personalizing patient prognosis and treatment is essential. Here, we evaluated miR-155, miR-21, miR-143, miR-145 and miR-451 that are implicated in LPS, as novel FFPE tissue biomarkers.

A total of 83 FFPE tissue specimens from primary LPS and lipomas (LPM) were analyzed. A proteinase K incubation-Trizol treatment coupled protocol was used for RNA isolation. After polyadenylation of total RNA and reverse transcription, expression analysis of 9 candidate reference and 5 target miRNAs was performed by qPCR. Genorm and NormFinder were used for finding the most suitable molecules for normalization. Survival analyses were performed in order to evaluate the prognostic potential of miRNAs.

MiR-103 and miR-191 are most suitable for normalization of miRNA expression in LPS. MiR-155 and miR-21 are clearly overexpressed (P<0.001) in LPS compared with LPM specimens, whereas miR-145 (P<0.001), miR-143 (P =0.008) and miR-451 (P=0.037) are underexpressed. MiR-155 (P=0.007) and miR-21 (P=0.029) are differentially expressed between well-differentiated, dedifferentiated, myxoid/round cell and pleomorphic LPs tumor subtypes. MiR-155 represents a novel independent indicator of unfavorable prognosis in LPS (HR = 2.97, 95% CI = 1.23–7.17, P = 0.016).

TLR4/ROS/miRNA-21 pathway underlies lipopolysaccharide instructed primary tumor outgrowth in lung cancer patients

Activation of Toll-like receptor 4 (TLR4) signaling in human lung cancer with lipopolysaccharide (LPS) enhances tumor progression. However, whether primary human lung cancer outgrowth could respond to LPS and underlying mechanisms are unclear. Here we determined that TLR4 activation with LPS promoted outgrowth of primary human lung cancer cells in vitro and in vivo. Mechanistically, LPS stimulation increased expression levels of microRNA-21 (miR-21) in primary human lung cancer cells. Inhibition of miR-21 blocked the enhanced lung cancer growth induced by LPS in vitro and in vivo. Up-regulation of miR-21 promoted outgrowth of primary human lung cancer. Down-regulation of miR-21 limited primary human lung cancer outgrowth. Further, TLR4 activation in primary human lung cancer cells increased their ROS levels. Scavenge of ROS abrogated the up-regulation of miR-21 in primary human lung cancer cells and attenuated LPS-induced outgrowth. For in vivo relevance, expression of TLR4 was correlated with miR-21 expression and ROS production in freshly isolated, untreated primary human lung cancer cells. These findings demonstrate an essential role of TLR4/ROS/miR-21 pathway in LPS-induced outgrowth of primary human lung cancer. Our study connected a framework of innate signaling, oxidative stress and microRNA in tumor immunity and provided clues for developing new therapeutics for lung cancer.

MicroRNAs and cancer: Key paradigms in molecular therapy

MicroRNAs (miRNAs) are a type of small non-coding RNA molecule that performs an important role in post-transcriptional gene regulation. Since miRNAs were first identified in 1993, a number of studies have demonstrated that they act as tumor suppressors or oncogenes in human cancer, including colorectal, lung, brain, breast and liver cancer, and leukemia. Large high-throughput studies have previously revealed that miRNA profiling is critical for the diagnosis and prognosis of patients with cancer, while certain miRNAs possess the potential to be used as diagnostic and prognostic biomarkers or therapeutic targets in cancer. The present study reviews the studies and examines the roles of miRNAs in cancer diagnosis, prognosis and treatment, and discusses the potential therapeutic modality of exploiting miRNAs.

MiR-504 inhibits cell proliferation and invasion by targeting LOXL2 in non small cell lung cancer

BACKGROUND

MicroRNAs (miRNAs) play crucial roles in tumor initiation and development. The aim of the study was to explore the clinicopathological role and functional effects of miR-504 in non small cell lung cancer (NSCLC).

METHODS

Quantitative reverse transcription polymerase chain reaction (QRT-PCR) was applied to detect the expression of miR-504 in 55 cases of NSCLC tissues and matched adjacent normal tissues in NSCLC patients. MTT, colony formation and transwell invasion assays were performed to evaluate the effects of miR-504 on cell proliferation and invasion, respectively. Dual luciferase reporter assay was used to verify that LOXL2 was a direct target of miR-504. QRT-PCR and western blot analysis were performed to analyze mRNA and protein expression.

RESULTS

In the study, we demonstrated that miR-504 was notably downregulated in NSCLC tissues compared with adjacent normal tissues. Lower miR-504 expression positively correlated with lymph node metastasis and advanced TNM stage in patients. Furthermore, upregulation of miR-504 significantly inhibited cell proliferation, cell invasion and EMT process of NSCLC. QRT-PCR, western blot and luciferase reporter assays confirmed that miR-504 could bind to LOXL2 3'UTR region and regulate its expression. Moreover, ectopic expression of LOXL2 could rescue the inhibiting effects on cell proliferation and invasion induced by miR-504 in NSCLC cells.

CONCLUSIONS

Our results indicated that miR-504 functioned as a tumor suppressor in NSCLC and may serve as a target of NSCLC treatment.

MicroRNA-21 inhibits mitochondria-mediated apoptosis in keloid

MicroRNA-21 acts as an oncogene by promoting cell proliferation and migration, whereas inhibiting apoptosis in majority of cancers. MicroRNA-21 is upregulated in human keloid fibroblasts. We hypothesized that microRNA-21 may contribute to pathogenesis of keloid fibroblasts. First, enhanced miR-21 but reduced mitochondrial-mediated apoptosis observed in keloid tissues indicated its importance in keloids development. Second, upregulation of microRNA-21 induced a decrease in the ratio of BAX to BCL-2 and suppressed mitochondrial fission in keloid fibroblasts. Third, by attenuating the decline in cellular mitochondrial membrane potential, overexpression of miR-21 suppressed cytochrome c release to the cytoplasm, followed by a decrease in the activity of intracellular caspase-9 and caspase-3, suggesting that mitochondrial-mediated proapoptotic pathway was impaired. Simultaneously, intracellular reactive oxygen species were decreased, indicating microRNA-21 undermined oxidative stress. This phenotype was reversed by miR-21 inhibition. Therefore, our study demonstrates that inhibition of microRNA-21 induces mitochondrial-mediated apoptosis in keloid fibroblasts, proposing microRNA-21 as a potential therapeutic target in keloid fibroblasts.

SSa ameliorates the Glu uptaking capacity of astrocytes in epilepsy via AP-1/miR-155/GLAST

BACKGROUND

Neuronal glutamate (Glu) release has been reported to mediate the neuronal injury of epilepsy, while Saikosaponin a (Ssa) was shown to ameliorate the epilepsy that induced by pentylenetetrazol (PTZ). However, potential interactions between glutamate release and Ssa has not been fully identified.

METHODS

Herein, PTZ-induced rat model were established to evaluate the neuron injury, while Ssa was used to treat the model rat. Rat astrocytes were isolated and induced by PTZ to construct cell models of epilepsy, real-time PCR and western blot were used to determine genes' expression. Luciferase reporter assay were performed to validate the relationship between miR-155-5p and glutamate aspartate transporter (GLAST). The level of Glu was sampled for HPLC measurement.

RESULTS

Ssa treatment could decrease the level of Glu in hippocampus of rat. PTZ-induced astrocytes pretreated with Ssa significantly decreased the expression of AP-1 and miR-155, but increased the expression of GLAST, furthermore, PTZ stimulation enables astrocytes to uptake large amount of extracellular Glu. AP-1 could bind with the promoter of miR-155 to promote its transcription. MiR-155 tragets GLAST to govern its expression.

CONCLUSION

Ssa treatment played pivotal roles in PTZ-induced epilepsy by promoting the expression of GLAT1 and uptaking of Glu, which was mediated by the expression of AP-1 and miR-155.

Biomarkers for early diagnosis, prognosis, prediction, and recurrence monitoring of non-small cell lung cancer

Despite advances in the management of non-small cell lung cancer, it remains to be the leading cause of cancer-related deaths worldwide primarily because of diagnosis at a late stage with an overall 5-year survival rate of 17%. A reduction in mortality was achieved by low-dose computed tomography screening of high-risk patients. However, the benefit was later challenged by the high false positive rate, resulting in unnecessary follow-ups, thus entailing a burden on both the health care system and the individual. The diagnostic dilemma imposed by imaging modalities has created a need for the development of biomarkers capable of differentiating benign nodules from malignant ones. In the past decade, with the advancements in high-throughput profiling technologies, a huge amount of work has been done to derive biomarkers to supplement clinical diagnosis. However, only a few of them have efficient sensitivity and specificity to be utilized in clinical settings. Therefore, there is an urgent need for the development of sensitive and specific means to detect and diagnose lung cancers at an early stage, when curative interventions are still possible. Due to the invasiveness of tissue biopsies and inability to capture tumor heterogeneity, nowadays enormous efforts have been invested in the development of technologies and biomarkers that enable sensitive and cost-effective testing using substrates that can be obtained in a noninvasive manner. This review, primarily focusing on liquid biopsy, summarizes all documented potential biomarkers for diagnosis, monitoring recurrence treatment response.

Circulating exosomal microRNAs as prognostic biomarkers for non-small-cell lung cancer

Exosomal miRNAs are proposed as excellent candidate biomarkers for clinical applications. However, little is known about their potential roles as prognostic biomarkers in lung cancer. In this study, we explored the prognostic value of plasma exosomal microRNAs (miRNAs) for non-small-cell lung cancer (NSCLC). Using a quantitative polymerase chain reaction (qPCR) array panel, we analyzed 84 plasma exosomal miRNAs in 10 lung adenocarcinoma patients and 10 matched healthy controls. The qPCR array showed 30 aberrantly expressed exosomal miRNAs. Nine candidate miRNAs were selected based on differential expression and previous reports for further evaluating their prognostic roles in 196 NSCLC patients. Elevated levels of exosomal miR-23b-3p, miR-10b-5p and miR-21-5p were independently associated with poor overall survival (with hazard ratio [95% confidence interval]: 2.42 (1.45 - 4.04), P = 0.001; 2.22 (1.18 - 4.16), P = 0.013; 2.12 (1.28 - 3.49), P = 0.003, respectively). When compared to the clinical prognostic variables only model, adding the three exosomal miRNA signatures significantly improved survival predictive accuracy with an increase of time-dependent area under the receiver operating characteristic curve from 0.88 to 0.91 (P=0.015). Our results indicated that plasma exosomal miR-23b-3p, miR-10b-5p and miR-21-5p are promising non-invasive prognostic biomarkers of NSCLC.

MicroRNA-21 versus microRNA-34: Lung cancer promoting and inhibitory microRNAs analysed in silico and in vitro and their clinical impact

MicroRNAs are well-known strong RNA regulators modulating whole functional units in complex signaling networks. Regarding clinical application, they have potential as biomarkers for prognosis, diagnosis, and therapy. In this review, we focus on two microRNAs centrally involved in lung cancer progression. MicroRNA-21 promotes and microRNA-34 inhibits cancer progression. We elucidate here involved pathways and imbed these antagonistic microRNAs in a network of interactions, stressing their cancer microRNA biology, followed by experimental and bioinformatics analysis of such microRNAs and their targets. This background is then illuminated from a clinical perspective on microRNA-21 and microRNA-34 as general examples for the complex microRNA biology in lung cancer and its diagnostic value. Moreover, we discuss the immense potential that microRNAs such as microRNA-21 and microRNA-34 imply by their broad regulatory effects. These should be explored for novel therapeutic strategies in the clinic.

MicroRNA-155 regulates arsenite-induced malignant transformation by targeting Nrf2-mediated oxidative damage in human bronchial epithelial cells

Arsenite is a well-documented human lung carcinogen but the detailed mechanisms of carcinogenesis remain unclear. In this study, human bronchial epithelial (16-HBE) cells were continuously exposed to 2.5μM arsenite for about 13 weeks to induce the phenotypes of malignant transformation. Our results showed that Nrf2 expression was gradually decreased whereas no significant change was observed on NF-κB activation with increased time of arsenite exposure. To test the roles of Nrf2-meidtaed oxidative damage in the arsenite-induced malignant transformation, we compared the levels of cGMP, PKG and oxidative damage-related indicators between arsenic-transformed cells and control cells. Our data demonstrated there were no significantly differences on the contents of cGMP, PKG, MDA and the production of ROS, but the levels of GSH and NO, the activities of SOD, tNOS and iNOS were significantly enhanced in the arsenic-transformed cells. Importantly, Nrf2 inactivation could be modulated by miR-155, and inhibition of miR-155 remarkably attenuated the malignant phenotypes and promoted apoptotic cell death in the arsenic-transformed cells. Together, our findings provide the novel mechanism that miR-155 may regulate arsenite-induced cell malignant transformation by targeting Nrf2-mediated oxidative damage, indicating that inhibition of miR-155 may be a potential strategy against lung carcinogenesis of arsenite.

MicroRNA profiling associated with non-small cell lung cancer: next generation sequencing detection, experimental validation, and prognostic value

Background

The average five-year survival for non-small cell lung cancer (NSCLC) patients is approximately 15%. Emerging evidence indicates that microRNAs (miRNAs) constitute a new class of gene regulators in humans that may play an important role in tumorigenesis. Hence, there is growing interest in studying their role as possible new biomarkers whose expression is aberrant in cancer. Therefore, in this study we identified dysregulated miRNAs by next generation sequencing (NGS) and analyzed their prognostic value.

Methods

Sequencing by oligo ligation detection technology was used to identify dysregulated miRNAs in a training cohort comprising paired tumor/normal tissue samples (N = 32). We validated 22 randomly selected differentially-expressed miRNAs by quantitative real time PCR in tumor and adjacent normal tissue samples (N = 178). Kaplan-Meier survival analysis and Cox regression were used in multivariate analysis to identify independent prognostic biomarkers.

Results

NGS analysis revealed that 39 miRNAs were dysregulated in NSCLC: 28 were upregulated and 11 were downregulated. Twenty-two miRNAs were validated in an independent cohort. Interestingly, the group of patients with high expression of both miRNAs (miR-21^high and miR-188^high) showed shorter relapse-free survival (RFS) and overall survival (OS) times. Multivariate analysis confirmed that this combined signature is an independent prognostic marker for RFS and OS (p = 0.001 and p < 0.0001, respectively).

Conclusions

NGS technology can specifically identify dysregulated miRNA profiles in resectable NSCLC samples. MiR-21 or miR-188 overexpression correlated with a negative prognosis, and their combined signature may represent a new independent prognostic biomarker for RFS and OS.

A new insight on reciprocal relationship between microRNA expression and epigenetic modifications in human lung cancer

Lung cancer stands among the leading causes of cancer-related death in the world. Although the molecular network implicated in lung cancer development is extensively revealed, the mortality rate is only slightly improved. MicroRNAs are small, endogenous single-stranded evolutionary conserved non-coding RNAs which involve in a wide variety of biological processes including cell growth, proliferation, metabolism, and differentiation. MicroRNAs, as novel biomarkers, have multiple functions in normal lung tissue development, and aberrant expression profiles of certain microRNAs could induce lung tumorigenesis. Similar to that of protein-coding genes, microRNA expression and function are regulated by multiple factors as well as the epigenetic network including DNA methylation and histone modification mechanisms. Furthermore, microRNAs can themselves regulate key enzymes which drive epigenetic modifications and have a pivotal effect on the cell biology. In this review, we will look into the regulatory loop linkage between microRNA expression and epigenetic modifications, and then, we will discuss the effects of epigenetics on the miRNome, as well as the role of epi-microRNAs in controlling the epigenome in human lung cancer. Better knowledge of reciprocal connection between microRNAs and epigenome will help to develop novel microRNA-orientated diagnostic, prognostic and therapeutic strategies related to human lung cancer in future.

Major Tumor Suppressor and Oncogenic Non-Coding RNAs: Clinical Relevance in Lung Cancer

Lung cancer is the leading cause of cancer deaths worldwide, yet there remains a lack of specific and sensitive tools for early diagnosis and targeted therapies. High-throughput sequencing techniques revealed that non-coding RNAs (ncRNAs), e.g., microRNAs and long ncRNAs (lncRNAs), represent more than 80% of the transcribed human genome. Emerging evidence suggests that microRNAs and lncRNAs regulate target genes and play an important role in biological processes and signaling pathways in malignancies, including lung cancer. In lung cancer, several tumor suppressor/oncogenic microRNAs and lncRNAs function as biomarkers for metastasis and prognosis, and thus may serve as therapeutic tools. In this review, recent work on microRNAs and lncRNAs is introduced and briefly summarized with a focus on potential biological and therapeutic applications.

Oncogenic role of microRNA-155 in mycosis fungoides: an in vitro and xenograft mouse model study

BACKGROUND

MicroRNA (miR)-155 contributes to the proliferation of mycosis fungoides (MF) in vitro and is upregulated in tumours of MF compared with early MF lesions.

OBJECTIVES

To investigate the contribution of miR-155 to the cancerous phenotype and drug resistance of MF/Sézary cell lines.

METHODS

miR-155 was inhibited in MF cell lines (MyLa and MJ) by transduction of miRZip anti-miR-155, and overexpressed in Hut78 cells by transduction of miRVec-miR-155; empty plasmids served as controls. Cells were analysed for response to inducers of apoptosis and cell-cycle arrest, using fluorescence-activated cell sorting. Transduced MyLa cells were subcutaneously injected into severe combined immunodeficient mice, and tumours were analysed immunohistochemically and for final size.

RESULT

MyLa and MJ cells expressed a high level of miR-155; Hut78 cells expressed a low level. MF cell lines stably expressing miR-155 inhibitor showed increased G2/M arrest in response to N-p-tolyl-2-(3,4,5-trimethoxyphenyl quinazolin-4-amine) (SL111), an inducer of cell-cycle arrest, followed by increased apoptosis. Additionally, they showed increased apoptosis in response to suberoylanilide hydroxamic acid (SAHA). Tumours formed in mice from injected anti-miR-155-expressing MyLa cells had a significantly lower volume and higher occurrence of apoptosis than controls. Stable overexpression of miR-155 in Hut78 cells had no effect.

CONCLUSIONS

Oncogenic miR-155 appears to contribute to the cancerous phenotype of MyLa and MJ cells, but not of Hut78 cells, by interrupting activation of the G2/M checkpoint in response to SL111, and decreasing apoptosis in response to SL111 and SAHA, thereby facilitating tumour growth. These findings have implications for the potential development of novel therapeutic modalities for MF incorporating miR-155 inhibitors.

Lung cancer in patients with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic fibrotic lung disease of unknown etiology. With a gradually increasing worldwide prevalence and a mortality rate exceeding that of many cancers, IPF diagnosis and management are critically important and require a comprehensive multidisciplinary approach. This approach also involves assessment of comorbid conditions, such as lung cancer, that exerts a dramatic impact on disease survival. Emerging evidence suggests that progressive lung scarring in the context of IPF represents a risk factor for lung carcinogenesis. Both disease entities present with major similarities in terms of pathogenetic pathways, as well as potential causative factors, such as smoking and viral infections. Besides disease pathogenesis, anti-cancer agents, including nintedanib, have been successfully applied in the treatment of patients with IPF while an oncologic approach with a cocktail of several pleiotropic anti-fibrotic agents is currently in the therapeutic pipeline of IPF. Nevertheless, epidemiologic association between IPF and lung cancer does not prove causality. Currently there is significant lack of knowledge supporting a direct association between lung fibrosis and cancer reflecting to disappointing therapeutic algorithms. An optimal therapeutic strategy for patients with both IPF and lung cancer represents an amenable need. This review article synthesizes the current state of knowledge regarding pathogenetic commonalities between IPF and lung cancer and focuses on clinical and therapeutic data that involve both disease entities.

MicroRNA-155 Downregulation Promotes Cell Cycle Arrest and Apoptosis in Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin’s lymphoma in the adult population, and treatment of DLBCL is still unfavorable. Therefore, there is an urgent requirement to investigate the molecular mechanisms underlying DLBCL tumorigenesis. To study the potential function of microRNA-155 (miR-155) involved in the regulation of lymphoma, we monitored lymphoma cell behavior including proliferation, cell cycle, and apoptosis using CCK-8 and flow cytometry analysis. Real-time PCR was used to detect the expression levels of miR-155 in 118 lymphoma patients’ tissues, and Western blot was also used to analyze the expression level of proteins correlated with cell cycle and apoptosis in lymphoma cells. miR-155 expression levels were higher in lymphoma tissues compared with adjacent tissues. Downregulation of miR-155 inhibited lymphoma cell progress by arresting cell cycle in the G₀/G₁ phase and promoting apoptosis. Cell cycle-correlated proteins (cyclin B1, cyclin D1, and CDK4) were inhibited by downregulation of miR-155. Apoptosis-correlated proteins level (Bax/Bcl-2 and caspase 3 activity) were increased by downregulation of miR-155. In addition, a significant inverse correlation between the level of miR-155 and transforming growth factor-β receptor 2 (TGFBR2) was observed, which has been demonstrated to be a novel tumor suppressor gene. A further in vivo tumor formation study in nude mice indicated that downregulation of miR-155 in lymphoma cells delayed the progress of tumor formation. These findings indicate that miR-155 may serve as a useful potential target for the treatment of lymphoma.

MIR155 Regulation of Ubiquilin1 and Ubiquilin2: Implications in Cellular Protection and Tumorigenesis

Ubiquilin (UBQLN) proteins are adaptors thought to link ubiquitinated proteins to the proteasome. However, our lab has recently reported a previously unappreciated role for loss of UBQLN in lung cancer progression. In fact, UBQLN genes are lost in over 50% of lung cancer samples examined. However, a reason for the loss of UBQLN has not been proposed, nor has a selective pressure that could lead to deletion of UBQLN been reported. Diesel Exhaust Particles (DEP) are a major concern in the large cities of developing nations and DEP exposed populations are at an increased risk of developing a number of illnesses, including lung cancer. A connection between DEP and UBQLN has never been examined. In the present study, we determined the effect of DEP on lung cell lines and were interested to determine if UBQLN proteins could potentially play a protective role following treatment with DEP. Interestingly, we found that DEP treated cells have increased expression of UBQLN proteins. In fact, over-expression of UBQLN was capable of protecting cells from DEP toxicity. To investigate the mechanism by which DEP leads to increased UBQLN protein levels, we identified and interrogated microRNAs that were predicted to regulate UBQLN mRNA. We found that DEP decreases the oncogenic microRNA, MIR155. Further, we showed that MIR155 regulates the mRNA of UBQLN1 and UBQLN2 in cells, such that increased MIR155 expression increased cell invasion, migration, wound formation and clonogenicity in UBQLN-loss dependent manner. This is the first report of an environmental carcinogen regulating expression of UBQLN proteins. We show that exposure of cells to DEP causes an increase in UBQLN levels and that MIR155 regulates mRNA of UBQLN. Thus, we propose that DEP-induced repression of MIR155 leads to increased UBQLN levels, which in turn may be a selective pressure on lung cells to lose UBQLN1.

Exosomes: a new horizon in lung cancer

Circulating exosomes are the major mediators of cell-cell communication. They have been found in various body fluids of healthy individuals and patients with malignancies as cargos of several molecules including miRNAs. Several studies have underlined the role of exosome miRNAs in different tumor types, including lung cancer, suggesting their potential use as biomarkers and therapeutic agents. An overview of the biology and function of exosomes and exosome miRNAs as indicators of diagnosis and treatment response in lung cancer is presented. In addition, preliminary data on exosomes as potential therapeutic agents are reported.

Direct quantitative detection for cell-free miR-155 in urine: a potential role in diagnosis and prognosis for non-muscle invasive bladder cancer

High recurrence rates of non-muscle invasive bladder cancer (NMIBC) in patients require lifelong testing and monitoring. The aim of this study is to develop a simplified RT-qPCR method (RT-qPCR-D) which directly quantifies cell-free miR-155 in urine without RNA extraction, and assess it as a potential tool in NMIBC detection. A pilot study including 60 urine samples was used to investigate the feasibility of RT-qPCR-D in detecting cell-free miR-155. Then, miR-155 levels were quantified in a large independent cohort of urine from 162 NIMBC patients, 76 cystitis patients, and 86 healthy donors using the RT-qPCR-D method. Changes of cell-free miR-155 before and after operation were also analyzed in 32 NIMBC patients. In pilot study, we found a significant linear association between RT-qPCR and RT-qPCR-D in urinary miR-155 detection. Both methods showed cell-free miR-155 were significantly increased in NMIBC patients, and could reflect their expression in tissues. Then, the increased expression of cell-free miR-155 was successfully validated in 162 NIMBC patients when compared with cystitis patients and healthy donors. Moreover, it distinguished NMIBC patients from others with 80.2% sensitivity and 84.6% specificity, which was superior to urine cytology. Cell-free miR-155 correlated with NMIBC stage and grade, and was an independent factor for predicting recurrence and progression to muscle invasion. In addition, cell-free miR-155 was significantly decreased after NMIBC patients underwent transurethral bladder resection. In conclusion, detection of cell-free miR-155 in urine using RT-qPCR-D is a simple and noninvasive approach which may be used for NMIBC diagnosis and prognosis prediction.

Plasma miR-145, miR-20a, miR-21 and miR-223 as novel biomarkers for screening early-stage non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality in the world. Late diagnosis is one of the most significant reasons for the high mortality rate of lung cancer. The identification of microRNAs (miRNAs) has opened a new field for molecular diagnosis of cancer. The purpose of the present study was to investigate whether plasma miRNAs may be used as biomarkers for early-stage NSCLC. A total of 232 participants, including 149 NSCLC patients and 83 healthy controls, were recruited between July 2012 and May 2014. We measured the levels of 10 miRNAs (miR-30d, miR-383, miR-20a, miR-145, miR-221, miR-25, miR-223, miR-21, miR-126 and miR-210) in plasma samples of 40 individuals (20 patients and 20 matched healthy controls) at the point of identification of disease, and 129 NSCLC patients and 83 healthy controls at the validation stage using reverse transcription-quantitative polymerase chain reaction. Receiver operating characteristics (ROC) curves were generated for each possible combination of the miRNAs. We observed that the expression of plasma miR-145, miR-20a, miR-21 and miR-223 was significantly increased in the early-stage NSCLC samples compared with controls. miRNAs have significant diagnostic value for early-stage NSCLC. Combined ROC analyses using these four miRNAs revealed an elevated area under the ROC curve (AUC) of 0.897, with a sensitivity and specificity of 81.8 and 90.1%, respectively. This AUC helped in distinguishing early-stage NSCLC. Furthermore, the levels of the four plasma miRNAs were significantly decreased following surgery (P<0.05). Altered expression of miR-145, miR-20a, miR-21 and miR-223 in plasma are of tumor origin, and the four miRNAs may represent potential novel non-invasive biomarkers for early-stage NSCLC.

Circulating Plasma MicroRNAs As Diagnostic Markers for NSCLC

Lung cancer is the most common cause of cancer deaths all over the world, in which non-small cell lung cancer (NSCLC) accounts for ~85% of cases. It is well known that microRNAs (miRNAs) play a critical role in various cellular processes, mediating post-transcriptional silencing either by mRNA degradation through binding the 3' UTR of target mRNA or by translational inhibition of the protein. In the past decade, miRNAs have also been increasingly identified in biological fluids such as human serum or plasma known as circulating or cell-free miRNAs, and may function as non-invasive diagnostic markers for various cancer types including NSCLC. Circulating tumor cells (CTCs) are those cells that are shed from solid tumors and then migrate into the circulation. However, reports concerning the roles of CTCs are quite rare, which may be attributed to the difficulties in the enrichment and detection of CTCs in the circulation. Although, there have been reassuring advances in identifying circulating miRNA-panels, which are assumed to be of diagnostic value in NSCLC early stage, some issues remain concerning the reliability of using miRNA panels as a diagnostic tool for NSCLC. In the current review, we are aiming at providing insights into the miRNAs biology, the mechanisms of miRNAs release into the bloodstream, cell-free miRNAs as the diagnostic markers for NSCLC and the current limitations of CTCs as diagnostic markers in NSCLC.

A functional variant in miR-155 regulation region contributes to lung cancer risk and survival

Emerging evidence suggested that upregulation of miR-155 could serve as a promising marker for the diagnosis and prognosis of non-small cell lung cancer (NSCLC). In the present study, we genotyped rs767649 (A > T) located in miR-155 regulation region in 1341 cases and 1982 controls, and analyzed the associations of rs767649 with NSCLC risk and survival. Consequently, rs767649 exhibited the significant associations with the risk (adjusted OR = 1.12, 95% CI = 1.01–1.24, P = 0.031) and prognosis of NSCLC (adjusted HR = 1.17, 95% CI = 1.03–1.32, P = 0.014). Meanwhile, rs767649 specifically interacted with radio-chemotherapy (P_int = 0.013), and patients with both the rs767649-TT genotype and radio-chemotherapy had the highest hazard ratio (adjusted HR = 1.65, 95% CI = 1.26–2.16, P < 0.001). Furthermore, using functional assays and The Cancer Genome Atlas (TCGA) Lung Adenocarcinoma (LUAD) dataset, we found that rs767649 variant allele could increase the transcriptional activity of miR-155, which in turn facilitated tumor growth and metastasis by inhibiting HBP1, TJP1, SMAD5 and PRKAR1A expression. Our findings suggested that rs767649 A > T might contribute to the increased risk and poor prognosis of NSCLC, highlighting the importance of rs767649 in the prevention and therapy of NSCLC.

Airway Secretory microRNAome Changes during Rhinovirus Infection in Early Childhood

BACKGROUND

Innate immune responses are fine-tuned by small noncoding RNA molecules termed microRNAs (miRs) that modify gene expression in response to the environment. During acute infections, miRs can be secreted in extracellular vesicles (EV) to facilitate cell-to-cell genetic communication. The purpose of this study was to characterize the baseline population of miRs secreted in EVs in the airways of young children (airway secretory microRNAome) and examine the changes during rhinovirus (RV) infection, the most common cause of asthma exacerbations and the most important early risk factor for the development of asthma beyond childhood.

METHODS

Nasal airway secretions were obtained from children (≤3 yrs. old) during PCR-confirmed RV infections (n = 10) and age-matched controls (n = 10). Nasal EVs were isolated with polymer-based precipitation and global miR profiles generated using NanoString microarrays. We validated our in vivo airway secretory miR data in an in vitro airway epithelium model using apical secretions from primary human bronchial epithelial cells (HBEC) differentiated at air-liquid interface (ALI). Bioinformatics tools were used to determine the unified (nasal and bronchial) signature airway secretory miRNAome and changes during RV infection in children.

RESULTS

Multiscale analysis identified four signature miRs comprising the baseline airway secretory miRNAome: hsa-miR-630, hsa-miR-302d-3p, hsa- miR-320e, hsa-miR-612. We identified hsa-miR-155 as the main change in the baseline miRNAome during RV infection in young children. We investigated the potential biological relevance of the airway secretion of hsa-mir-155 using in silico models derived from gene datasets of experimental in vivo human RV infection. These analyses confirmed that hsa-miR-155 targetome is an overrepresented pathway in the upper airways of individuals infected with RV.

CONCLUSIONS

Comparative analysis of the airway secretory microRNAome in children indicates that RV infection is associated with airway secretion of EVs containing miR-155, which is predicted in silico to regulate antiviral immunity. Further characterization of the airway secretory microRNAome during health and disease may lead to completely new strategies to treat and monitor respiratory conditions in all ages.

High copy number variation of cancer-related microRNA genes and frequent amplification of DICER1 and DROSHA in lung cancer

A growing body of evidence indicates that miRNAs may be a class of genetic elements that can either drive or suppress oncogenesis. In this study we analyzed the somatic copy number variation of 14 miRNA genes frequently found to be either over- or underexpressed in lung cancer, as well as two miRNA biogenesis genes, DICER1 and DROSHA, in non-small-cell lung cancer (NSCLC). Our analysis showed that most analyzed miRNA genes undergo substantial copy number alteration in lung cancer. The most frequently amplified miRNA genes include the following: miR-30d, miR-21, miR-17 and miR-155. We also showed that both DICER1 and DROSHA are frequently amplified in NSCLC. The copy number variation of DICER1 and DROSHA correlates well with their expression and survival of NSCLC and other cancer patients. The increased expression of DROSHA and DICER1 decreases and increases the survival, respectively. In conclusion, our results show that copy number variation may be an important mechanism of upregulation/downregulation of miRNAs in cancer and suggest an oncogenic role for DROSHA.

Aberrant expression of miR-21, miR-376c and miR-145 and their target host genes in Merkel cell polyomavirus-positive non-small cell lung cancer

Merkel Cell Polyoma Virus (MCPyV) infection has been associated with non-small cell lung cancer (NSCLC). Viruses can manipulate cellular miRNAs or have a profound impact on cellular miRNA expression to control host regulatory pathways. In this study, we evaluated the expression profiles of cancer-associated and virally affected host microRNAs miR-21, miR-145, miR-146a, miR-155, miR-302c, miR-367 and miR-376c in a series of NSCLC tissue samples as well as in samples from “healthy” sites, distant from the tumour region that were either positive or negative for MCPyV DNA. miR-21 and miR-376c were significantly upregulated whereas miR-145 was significantly downregulated in the MCPyV+ve samples compared to the MCPyV-ve tumour samples. Overall, miR-21 and miR-376c expression was higher in tumour compared to healthy tissue samples. No association was observed between the miR-155, miR-146a, miR-302c and miR-367 levels and the presence of MCPyV. The expression of miR-21 target genes (Pten, Bcl-2, Daxx, Pkr, Timp3), miR-376c (Grb2, Alk7, Mmp9) and miR-145 (Oct-4, Sox2, Fascin1) and their associated pathways (Braf, Akt-1, Akt-2, Bax, Hif1a, p53) was altered between MCPyV+ve tumor samples and their corresponding controls. These results show a novel association between miR-21, miR-376c and miR-145 and their host target genes with the presence of MCPyV, suggesting a mechanism of virus-specific microRNA signature in NSCLC.