Low miR-145 silenced by DNA methylation promotes NSCLC cell proliferation, migration and invasion by targeting mucin 1

Extracellular circulating miRNAs as potential non-invasive biomarkers in non-small cell lung cancer patients

Non-small cell lung cancer (NSCLC) comprises 85% of all lung cancers and is a malignant condition resistant to advanced-stage treatment. Despite the advancement in detection and treatment techniques, the disease is taking a deadly toll worldwide, being the leading cause of cancer death every year. Current diagnostic methods do not ensure the detection of the disease at an early stage, nor can they predict the risk of its development. There is an urgent need to identify biomarkers that can help predict an individual's risk of developing NSCLC, distinguish NSCLC subtype, allow monitor disease and treatment progression which can improve patient survival. Micro RNAs (miRNAs) represent the class of small and non-coding RNAs involved in gene expression regulation, influencing many biological processes such as proliferation, differentiation, and carcinogenesis. Research reports significant differences in miRNA profiles between healthy and neoplastic tissues in NSCLC. Its abundant presence in biofluids, such as serum, blood, urine, and saliva, makes them easily detectable and does not require invasive collection techniques. Many studies support miRNAs' importance in detecting, predicting, and prognosis of NSCLC, indicating their utility as a promising biomarker. In this work, we reviewed up-to-date research focusing on biofluid miRNAs' role as a diagnostic tool in NSCLC cases. We also discussed the limitations of applying miRNAs as biomarkers and highlighted future areas of interest.

MiR-145 modulates the radiosensitivity of non-small cell lung cancer cells by suppression of TMOD3

Radioresistance is a major problem encountered in the treatment of non-small cell lung cancer (NSCLC). Aberrant microRNA (miRNA) expression contributes to multiple cancer‑associated signaling pathways, and profoundly influences effects of radiotherapy (RT) in cancers. MicroRNA-145-5p (miR-145) is recognized as a tumor suppresser in NSCLC. However, the roles of miR-145 during radiotherapy of NSCLC are largely unknown. The present study aimed to investigate the function and underlying mechanism of miR-145 in modulation of radiosensitivity in NSCLC. We generated radioresistant H460 and A549 subclones, named H460R and A549R, respectively, and found that irradiation (IR) could suppress the expression levels of miR-145 in radioresistant NSCLC cells. Furthermore, overexpression of miR-145 could sensitize radioresistant NSCLC cells to IR, while knockdown of miR-145 in NSCLC cells acted the converse manner. Mechanically, miR-145 was able to directly target 3'UTR of tropomodulin 3 (TMOD3) mRNA and decrease the expression of TMOD3 at the levels of mRNA and protein. Additionally, we confirmed that miR-145 could enhance the radiosensitivity of radioresistant NSCLC cells by targeting TMOD3 in vitro and in vivo, and could be used as a target in clinical treatment of NSCLC. Collectively, restoration of miR-145 expression increases the radiosensitivity of radioresistant NSCLC cells by suppression of TMOD3, and miR-145 can act as a new radiosensitizer for NSCLC therapy.

Diagnostic and prognostic value of serum miR-145 and vascular endothelial growth factor in non-small cell lung cancer

Previous studies have reported the diagnostic and prognostic value of serum microRNA (miR)-145 and vascular endothelial growth factor (VEGF) levels in various types of cancer; however, their clinical use in non-small cell lung cancer (NSCLC) remains unclear. The present study included 215 patients, 106 with NSCLC and 109 with other lung diseases (OLDs). miR-145 expression levels were determined using reverse transcription-quantitative PCR (RT-qPCR) and VEGF levels were measured using an ELISA. The diagnostic performance was assessed using a receiver operating characteristic curve and area under the curve (AUC) analysis. A Kaplan-Meier survival curve and Cox regression analysis were employed to evaluate the prognostic significance of the markers. The biological function of miR-145 was examined in A549 and H1792 cell lines. The effects of miR-145 on cell proliferation of NSCLC cells were evaluated by flow cytometry, and the expression levels of miR-145 and cell cycle-related genes were determined by RT-qPCR. The results revealed that miR-145 and VEGF exhibited fair diagnostic performance [AUC, 0.61 (95% CI, 0.55-0.68) and AUC, 0.64 (95% CI, 0.57-0.71), respectively]. Combining age and smoking status with miR-145 and VEGF provided the best model for differentiating patients with NSCLC from those with OLDs (AUC, 0.76; 95% CI, 0.69-0.83). Furthermore, low serum miR-145 levels were associated with poor overall survival [hazard ratio (HR), 0.48; 95% CI, 0.27-0.85], whereas high VEGF levels were not associated with poor overall survival (HR, 1.47; 95% CI, 0.81-2.68). In addition, the results of the in vitro experiments indicated that miR-145 decreased cell proliferation via the induction of cell cycle arrest. In conclusion, the findings of the present study suggested that combining miR-145 and VEGF levels with clinical risk factors may be a potential diagnostic scheme for NSCLC. In addition, serum miR-145 may be used as a prognostic marker. These results indicated that miR-145 may function as a tumor suppressor in NSCLC.

Ascites in ovarian cancer: MicroRNA deregulations and their potential roles in ovarian carcinogenesis

Ovarian cancer comprises the most lethal gynecologic malignancy and is accompanied by the high potential for the incidence of metastasis, recurrence and chemotherapy resistance, often associated with a formation of ascitic fluid. The differentially expressed ascites-derived microRNAs may be linked to ovarian carcinogenesis. The article focuses on a number of miRNAs that share a common expression pattern as determined by independent studies using ascites samples and with regard to their functions and outcomes in experimental and clinical investigations.Let-7b and miR-143 have featured as tumor suppressors in ovarian cancer, which is in line with data on other types of cancer. Although two miRNAs, i.e. miR-26a-5p and miR-145-5p, act principally as tumor suppressor miRNAs, they occasionally exhibit oncogenic roles. The performance of miR-95-3p, upregulated in ascites, is open to debate given the current lack of supportive data on ovarian cancer; however, data on other cancers indicates its probable oncogenic role. Different findings have been reported for miR-182-5p and miR-200c-3p; in addition to their presumed oncogenic roles, contrasting findings have indicated their ambivalent functions. Further research is required for the identification and evaluation of the potential of specific miRNAs in the diagnosis, prediction, treatment and outcomes of ovarian cancer patients.

LncRNA SENCR promotes cell proliferation and progression in non-small-cell lung cancer cells via sponging miR-1-3p

ABBREVIATION

NSCLC: Non-small cell lung cancer.

The Risks of miRNA Therapeutics: In a Drug Target Perspective

RNAi therapeutics have been growing. Patisiran and givosiran, two siRNA-based drugs, were approved by the Food and Drug Administration in 2018 and 2019, respectively. However, there is rare news on the advance of miRNA drugs (another therapeutic similar to siRNA drug). Here we report the existing obstacles of miRNA therapeutics by analyses for resources available in a drug target perspective, despite being appreciated when it began. Only 10 obtainable miRNA drugs have been in clinical trials with none undergoing phase III, while over 60 siRNA drugs are in complete clinical trial progression including two approvals. We mechanically compared the two types of drug and found that their major distinction lay in the huge discrepancy of the target number of two RNA molecules, which was caused by different complementary ratios. One miRNA generally targets tens and even hundreds of genes. We named it “too many targets for miRNA effect” (TMTME). Further, two adverse events from the discontinuation of two miRNA therapeutics were exactly answered by TMTME. In summary, TMTME is inevitable because of the special complementary approach between miRNA and its target. It means that miRNA therapeutics would trigger a series of unknown and unpreventable consequences, which makes it a considerable alternative for application.

MiR-145: a potential biomarker of cancer migration and invasion

MircoRNAs (miRNAs) are a diverse family of highly-conserved small non-coding RNAs, which range from approximately 18 to 25 nucleotides in size. They regulate gene expression transcriptionally or post-transcriptionally via binding to the 3'-untranslated region (3'-UTR) of target message RNAs (mRNAs). MiRNAs have emerged as molecular regulators that participate in physiological and pathological processes of diverse malignancies. Among them, miRNA-145 (miR-145) played a profound role in tumorigenesis and progression of various neoplasms. In this review, we summarized the recent findings regarding miR-145, to elucidate its functional roles in cell invasion and migration of diverse human malignancies, and considered it a potential biomarker for cancer diagnosis, screening, and prognosis.

Exploration of bladder cancer-associated methylated miRNAs by methylated DNA immunoprecipitation sequencing

BACKGROUND

The current study aimed to explore the association between two epigenomic components, miRNA and DNA methylation, in bladder cancer (BC).

METHODS

Eight paired samples of tumor tissue and matched adjacent normal tissues from BC patients were subjected to methylated DNA immunoprecipitation sequencing and sRNA-Seq for differentially methylated miRNA genes and differential miRNA analysis. The miRNAs regulated by DNA methylation were screened and their functions involved in BC were analyzed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) as well as a miRNA-mRNA interaction network.

RESULTS

The methylation levels of 212 genes were different between tumors and normal tissues with specific enrichment at transcription initiation and termination sites. Among these genes, 154 were hypermethylated and 58 were hypomethylated. GO and KEGG pathway enrichment analysis indicated that differentially methylated miRNA genes were mainly enriched in tumor-associated GO terms and signaling pathways. Pairwise statistical analysis of MeDIP-Seq and sRNA-Seq data showed that there are 154 and 165 candidate methylation-regulated genes in tumors and normal tissues, respectively. Notably, an interaction network indicated that the miRNAs regulated by methylation regulated a broad range of mRNAs associated with cancer development and progression. In particular, the most differentially expressed miRNAs were validated by qRT-PCR, such that miR-145-5p was downregulated and miR-182-5p was upregulated in patients with bladder cancer.

CONCLUSION

A large number of miRNA genes were modified by methylation in BC. Identification of changes in the expression of these miRNAs provides a great deal of important information for BC diagnosis.

Retracted: miR-145 modulates epithelial-mesenchymal transition and invasion by targeting ZEB2 in non-small cell lung cancer cell lines

Lung cancer is the leading cause of cancer-related deaths worldwide. Epithelial-mesenchymal transition (EMT) is a major event that drives cancer progression. Here we aim to investigate the role of microRNA, miR-145, in regulating EMT of the highly invasive non-small cell lung cancer (NSCLC). Quantitative real-time polymerase chain reaction analysis indicated that miR-145 was downregulated in cancer tissue compared with that in adjacent normal tissue. NSCLC cell lines, namely H1299, PC7, and SPCA-1, also demonstrated miR-145 downregulation, which is correlated well with their invasive ability, assessed by the Matrigel invasion assay. miR-145 overexpression resulted in downregulation of N-cadherin, and downregulation of vimentin and E-cadherin, suggesting a decreased EMT activity. TargetScan analysis predicted that a binding site exists between miR-145 and an oncogene, ZEB2, which was verified using the dual-luciferase assay. Alteration of miR-145 expression also induced inverse effects on ZEB2 expression, and a negative correlation exists between ZEB2 and miR-145 in human tissues. ZEB2 and miR-145 also exerted antagonizing effects on the invasion of NSCLC cells. Therefore, miR-145 is an important molecule in NSCLC that regulates cancer EMT through targeting ZEB2.

Epigenetic mechanism and target therapy of UHRF1 protein complex in malignancies

Ubiquitin-like with plant homeodomain and really interesting new gene finger domains 1 (UHRF1) functions as an epigenetic regulator recruiting PCNA, DNMT1, histone deacetylase 1, G9a, SuV39H, herpes virus-associated ubiquitin-specific protease, and Tat-interactive protein by multiple corresponding domains of DNA and H3 to maintain DNA methylation and histone modifications. Overexpression of UHRF1 has been found as a potential biomarker in various cancers resulting in either DNA hypermethylation or global DNA hypo-methylation, which participates in the occurrence, progression, and invasion of cancer. The role of UHRF1 in the reciprocal interaction between DNA methylation and histone modifications, the dynamic structural transformation of UHRF1 protein within epigenetic code replication machinery in epigenetic regulations, as well as modifications during cell cycle and chemotherapy targeting UHRF1 are evaluated in this study.

The Prognostic Value and Regulatory Mechanisms of microRNA-145 in Various Tumors: A Systematic Review and Meta-analysis of 50 Studies

Acting as an important tumor-related miRNA, the clinical significance and underlying mechanisms of miR-145 in various malignant tumors have been investigated by numerous studies. This study aimed to comprehensively estimate the prognostic value and systematically illustrate the regulatory mechanisms of miR-145 based on all eligible literature.Relevant studies were acquired from multiple online databases. Overall survival (OS) and progression-free survival (PFS) were used as primary endpoints. Detailed subgroup analyses were performed to decrease the heterogeneity among studies and recognize the prognostic value of miR-145. All statistical analyses were performed with RevMan software version 5.3 and STATA software version 14.1. A total of 48 articles containing 50 studies were included in the meta-analysis. For OS, the pooled results showed that low miR-145 expression in tumor tissues was significantly associated with worse OS in patients with various tumors [HR = 1.70; 95% confidence interval (CI), 1.46-1.99; P < 0.001). Subgroup analysis based on tumor type showed that the downregulation of miR-145 was associated with unfavorable OS in colorectal cancer (HR = 2.17; 95% CI, 1.52-3.08; P < 0.001), ovarian cancer (HR = 2.15; 95% CI, 1.29-3.59; P = 0.003), gastric cancer (HR = 1.78; 95% CI, 1.35-2.36; P < 0.001), glioma (HR = 1.65; 95% CI, 1.30-2.10; P < 0.001), and osteosarcoma (HR = 2.28; 95% CI, 1.50-3.47; P < 0.001). For PFS, the pooled results also showed that the downregulation of miR-145 was significantly associated with poor PFS in patients with multiple tumors (HR = 1.39; 95% CI, 1.16-1.67; P < 0.001), and the subgroup analyses further identified that the low miR-145 expression was associated with worse PFS in patients with lung cancer (HR = 1.97; 95% CI, 1.25-3.09; P = 0.003) and those of Asian descent (HR = 1.50; 95% CI, 1.23-1.82; P < 0.001). For the regulatory mechanisms, we observed that numerous tumor-related transcripts could be targeted by miR-145-5p or miR-145-3p, as well as the expression and function of miR-145-5p could be regulated by multiple molecules.This meta-analysis indicated that downregulated miR-145 in tumor tissues or peripheral blood predicted unfavorable prognostic outcomes for patients suffering from various malignant tumors. In addition, miR-145 was involved in multiple tumor-related pathways and the functioning of significant biological effects. miR-145 is a well-demonstrated tumor suppressor, and its expression level is significantly correlated with the prognosis of patients with multiple malignant tumors.

miR-431-5p alters the epithelial-to-mesenchymal transition markers by targeting UROC28 in hepatoma cells

OBJECTIVE

MicroRNA (miR)-431 plays an essential role in various human cancer types, particularly in the process of invasion. However, the function and mechanism of miR-431-5p in the invasion of hepatocellular carcinoma (HCC) remain undefined.

METHODS

The expression levels of miR-431-5p and its potential target protein UROC28 in hepatocellular carcinoma cells and tissues were detected, and the levels of EMT markers in vivo and in vitro were also detected.

RESULTS

MiR-431-5p was downregulated in HCC cell lines and tissues and associated with vascular invasion and tumor encapsulation. Furthermore, miR-431-5p was able to influence the epithelialto-mesenchymal transition (EMT) process in HCCLM3 and HUH7 cells. Mechanistically, it was discovered that miR-431-5p repressed invasion by targeting UROC28. Furthermore, miR-431-5p influenced the EMT markers in HCCLM3 and HUH7 cells by downregulating UROC28 expression. Similarly, in vivo assays confirmed that miR-431-5p upregulation in HCC cells remarkably inhibited tumor proliferation and influenced the EMT markers.

CONCLUSION

The current study has demonstrated that the miR-431-5p/UROC28 axis acts possible influence on the EMT in HCC. Upregulation of miR-431-5p could be an original approach for inhibiting tumor invasion.

Increased MALAT1 expression contributes to cisplatin resistance in non-small cell lung cancer

Cisplatin-based chemotherapy is commonly used for the clinical treatment of patients with non-small cell lung cancer (NSCLC). However, the anti-tumor efficacy of cisplatin is limited by poor clinical response and the development of chemoresistance. At present, the underlying mechanism for cisplatin resistance remains unclear. In the present study, it was identified that metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long non-coding RNA that has been demonstrated to function as an oncogene, was increased in tumor tissues from patients with cisplatin-resistant NSCLC. In addition, the MALAT1 level was increased in A549rCDDP cells compared with the parental A549 cells. Silencing of MALAT1 sensitized A549rCDDP cells to cisplatin treatment, while overexpression of MALAT1 in A549 cells decreased their sensitivity towards cisplatin. Through analysis of the gene expression in patient samples, a decrease in miR-145 and an increase in Kruppel-like factor 4 (KLF4) in tumor tissues compared with adjacent normal tissues was observed. A negative association between MALAT1 and miR-145 was also identified in A549 cells and A549rCDDP cells. Furthermore, reverse transcription quantitative polymerase chain reaction and western blotting identified that KLF4 was positively and negatively regulated by MALAT1 and miR-145, respectively. The direct regulatory association between MALAT1 and miR-145 and the target gene KLF4 was additionally confirmed using a luciferase reporter assay. Knockdown of MALAT1 reversed cisplatin resistance in A549rCDDP cells. Taken together, these data indicated that MALAT1 decreased the sensitivity of NSCLC to cisplatin via the regulation of miR-145 and KLF4.

The role of plasma miRNAs in the diagnosis of pulmonary nodules

Background

In this study, we aimed to assess the clinical utility of detection of plasma microRNAs (miRNAs) in the diagnosis of pulmonary nodules.

Methods

Fifty-seven patients with pulmonary nodules who had undergone surgery were enrolled in our study from July 2016 to July 2017 at Sun Yat-sen University Cancer Center. We measured the expression levels of 12 miRNAs (miRNA-17, -146a, -200b, -182, -155, -221, -205, -126, -7, -21, -145, and miRNA-210) in plasma samples of 57 patients, including 15 benign pulmonary nodules patients and 42 malignant pulmonary nodules patients. The levels of these miRNAs were detected by Real-time quantitative polymerase chain reaction (RT-PCR). The receiver operating characteristic (ROC) curve was used to assess the diagnostic performance of plasma miRNAs for non-small cell lung cancer (NSCLC).

Results

The expression levels of plasma miRNA-17, -146a, -200b, -182, -155, -221, -205, -126, -7, -21, -145, and miRNA-210 are not associated with gender, age, pTNM stage, differentiation grade. The levels of miRNA-17, -146a, -200b, -182, -221, -205, -7, -21, -145, and miRNA-210 in NSCLC patients are significantly higher than those in benign pulmonary nodules patients (P<0.05). However, there are no significant differences for the expression levels of miRNA-155 and miRNA-126. For diagnosing NSCLC, the sensitivity and specificity was 66.7% and 80.0% for miRNA-17, 54.8% and 86.7% for miRNA-146a, 64.3% and 86.7% for miRNA-200b, 83.3% and 73.3% for miRNA-182, 54.8% and 80.0% for miRNA-221, 73.8% and 80.0% for miRNA-205, 78.6% and 73.3% for miRNA-7, 78.6% and 60.0% for miRNA-21, 78.6% and 73.3% for miRNA-145, 76.2% and 73.3% for miRNA-210.

Conclusions

Plasma miRNAs (miRNA-17, -146a, -200b, -182, -221, -205, -7, -21, -145, and miRNA-210) have relatively high sensitivity and specificity for the diagnosis of NSCLC. These plasma miRNAs may be the potential biomarkers for early diagnosis of lung cancer.

Epigenetics and MicroRNAs in Cancer

The ability to reprogram the transcriptional circuitry by remodeling the three-dimensional structure of the genome is exploited by cancer cells to promote tumorigenesis. This reprogramming occurs because of hereditable chromatin chemical modifications and the consequent formation of RNA-protein-DNA complexes that represent the principal actors of the epigenetic phenomena. In this regard, the deregulation of a transcribed non-coding RNA may be both cause and consequence of a cancer-related epigenetic alteration. This review summarizes recent findings that implicate microRNAs in the aberrant epigenetic regulation of cancer cells.

miR-145-5p inhibits epithelial-mesenchymal transition via the JNK signaling pathway by targeting MAP3K1 in non-small cell lung cancer cells

Lung cancer is one of the most common types of tumors and the leading cause of cancer-associated mortality in the world. Additionally, non-small cell lung cancer (NSCLC) accounts for ~80% of all lung cancer cases. Epithelial-mesenchymal transition (EMT) is an important cell biological process, which is associated with cancer migration, metastasis, asthma and fibrosis in the lung. In the present study, it was revealed that miR-145-5p was able to suppress EMT by inactivating the c-Jun N-terminal kinase (JNK) signaling pathway in NSCLC cells. Mitogen-activated protein kinase kinase kinase 1 (MAP3K1) was predicted and confirmed to be a novel target of miR-145-5p. Overexpression of MAP3K1 was able to reverse the inhibition of EMT induced by miR-145-5p via the JNK signaling pathway. Overall, the results revealed that miR-145-5p inhibits EMT via the JNK signaling pathway by targeting MAP3K1 in NSCLC cells.

microRNA-145-3p inhibits non-small cell lung cancer cell migration and invasion by targeting PDK1 via the mTOR signaling pathway

The mammalian target of rapamycin (mTOR) pathway is dysregulated in more than 50% of all human malignancies and is a major target in cancer treatment. In this study, we explored the underlying mechanism involving microRNA-145-3p (miR-145-3p) in the development and progression of non-small cell lung cancer (NSCLC) by targeting PDK1 via the mTOR signaling pathway. NSCLC tissues and adjacent normal tissues were obtained from 83 NSCLC patients. miR-145-3p, PDK1, and mTOR levels were determined by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry. Human NSCLC cell lines A549 and H1299 were transfected with miR-145-3p and siPDK1 to confirm the effect of miR-145-3p and PDK1 on NSCLC cells in vitro. Cell growth was evaluated by a CCK8 assay. Cell motility and chemotaxis analysis were determined by the scratch test and chemotaxis assay, respectively. The protein levels of PDK1 and mTOR were measured using the western blotting. Results showed lower level of miR-145-3p and higher levels of PDK1 and mTOR in NSCLC tissues compared to the adjacent normal tissues. In vitro results showed that cell growth, cell motility, and chemotaxis were all inhibited in cells transfected with miR-145-3p and those transfected with siPDK. Additionally, dual luciferase reporter gene assay helped confirmed that PDK1 is a target of miR-145. Finally, levels of PDK1, mTOR, and phosphorylated-mTOR were lower in cells transfected with miR-145-3p as well as those with siPDK1. These findings indicate that miR-145-3p may inhibit cell growth, motility, and chemotaxis in NSCLC by targeting PDK1 through suppressing the mTOR pathway.

Placental Homing Peptide-microRNA Inhibitor Conjugates for Targeted Enhancement of Intrinsic Placental Growth Signaling

Suboptimal placental growth and development are the underlying cause of many pregnancy complications. No treatments are available, primarily due to the risk of causing fetal teratogenicity. microRNAs (miRNAs) are short, non-coding RNA sequences that regulate multiple downstream genes; miR-145 and miR675 have previously been identified as negative regulators of placental growth. In this proof of principle study, we explored the feasibility of delivering miRNA inhibitors to the placentas of pregnant mice and developed novel placental homing peptide-microRNA inhibitor conjugates for targeted enhancement of intrinsic placental growth signalling. Scrambled-, miR-145- or miR-675 inhibitor sequences were synthesised from peptide nucleic acids and conjugated to the placental homing peptide CCGKRK. Intravenous administration of the miR-145- and miR-675 conjugates to pregnant C57BL/6J mice significantly increased fetal and placental weights compared to controls; the miR-675 conjugate significantly reduced placental miR-675 expression. When applied to human first trimester placental explants, the miR-145 conjugate significantly reduced placental miR-145 expression, and both conjugates induced significant enhancement of cytotrophoblast proliferation; no effect was observed in term placental explants. This study demonstrates that homing peptide-miRNA inhibitor conjugates can be exploited to promote placental growth; these novel therapeutics may represent an innovative strategy for targeted treatment of compromised placental development.

Deregulation of miRNAs in malignant pleural mesothelioma is associated with prognosis and suggests an alteration of cell metabolism

Malignant pleural mesothelioma (MPM) is an aggressive human cancer and miRNAs can play a key role for this disease. In order to broaden the knowledge in this field, the miRNA expression was investigated in a large series of MPM to discover new pathways helpful in diagnosis, prognosis and therapy. We employed nanoString nCounter system for miRNA profiling on 105 MPM samples and 10 healthy pleura. The analysis was followed by the validation of the most significantly deregulated miRNAs by RT-qPCR in an independent sample set. We identified 63 miRNAs deregulated in a statistically significant way. MiR-185, miR-197, and miR-299 were confirmed differentially expressed, after validation study. In addition, the results of the microarray analysis corroborated previous findings concerning miR-15b-5p, miR-126-3p, and miR-145-5p. Kaplan-Meier curves were used to explore the association between miRNA expression and overall survival (OS) and identified a 2-miRNA prognostic signature (Let-7c-5p and miR-151a-5p) related to hypoxia and energy metabolism respectively. In silico analyses with DIANA-microT-CDS highlighted 5 putative targets in common between two miRNAs. With the present work we showed that the pattern of miRNAs expression is highly deregulated in MPM and that a 2-miRNA signature can be a new useful tool for prognosis in MPM.

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

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

Correlation between mucin biology and tumor heterogeneity in lung cancer

Mucins (MUC) are a family consisting of large O-glycoproteins whose primary functions are to protect and lubricate cell epithelial surfaces and contribute to intra- and inter-cellular signal pathways, cell proliferation, growth and apotosis. With the development of new technologies, MUCs begin to be identified as an effective marker in evaluating the tumor heterogeneity in lung cancer. MUCs' diverse expressions in subtypes of lung cancer indicate the inter-tumor heterogeneity. MUCs' mutation may also contribute to the development of intra-heterogeneity and evolution of lung cancer. Understanding MUCs' association with lung cancer heterogeneity and its molecular regulatory mechanism will benefit the development of diagnosis, therapy choice, and prognosis prediction of lung cancer.

Methylation of miR-145a-5p promoter mediates adipocytes differentiation

MicroRNAs (miRNAs, miR) play important roles in adipocyte development. Recent studies showed that the expression of several miRNAs is closely related with promoter methylation. However, it is not known whether miRNA mediates adipocytes differentiation by means of DNA methylation. Here, we showed that miR-145a-5p was poorly expressed in adipose tissue from mice fed a high fat diet (HFD). Overexpression or inhibition of miR-145a-5p was unfavorable or beneficial, respectively, for adipogenesis, and these effects were achieved by regulating adipocyte-specific genes involved in lipogenic transcription, fatty acid synthesis, and fatty acid transportation. Particularly, we first suggested that miR-145a-5p mimics or inhibitors promoted or repressed adipocytes proliferation by regulating p53 and p21, which act as cell cycle regulating factors. Surprisingly, the miR-145a-5p-repressed adipocyte differentiation was enhanced or rescued when cells treated with 5-Aza-dC were transfected with miR-145a-5p mimics or inhibitors, respectively. These data indicated that, as a new mean to positively regulate adipocyte proliferation, the process of miR-145a-5p-inhibited adipogenesis may be regulated by DNA methylation.

The role of microRNA in metastatic processes of non-small cell lung carcinoma

BACKGROUND

MicroRNAs are small non-coding one-stranded RNA molecules that play an important role in the post-transcriptional regulation of genes. Bioinformatic predictions indicate that each miRNA can regulate hundreds of target genes. MicroRNA expression can be associated with various cellular processes leading to the metastasis of malignant tumours including non-small cell lung carcinoma. This review summarizes current knowledge on the role of microRNAs in NSCLC metastasis to the brain and lymph nodes.

METHODS

A search of the NCBI/PubMed database for publications on expression levels and the mechanisms of microRNA action in NSCLC metastasis.

RESULTS AND CONCLUSION

Dysregulation of microRNAs in NSCLC can be associated with brain and lymph node metastasis. There are differences in microRNA expression profiling between NSCLC with and without metastases but it is currently not possible to reliably predict the site of metastasis in NSCLC. Based on data from RNAmicroarrays, bioinformatics analysis is able to predict the target genes of highlighted microRNAs, providing us with complex information about cancer cell features such as enhanced proliferation, migration and invasion. Such microRNAs may then be knocked-down using siRNAs or substituted with miRNA mimics. RNA microarray profiling may thus be a useful tool to select up- or down-regulated microRNAs. A number of authors suggest that microRNAs could serve as biomarkers and therapeutic targets in the treatment of NSCLC metastasis.