The roles of microRNAs in the regulation of tumor metastasis

MicroRNAs as biomarkers in brain metastasis

Cancer patients face a particularly daunting obstacle when tumors spread to the brain, a condition that substantially increases mortality rates. Traditional diagnostic tools have proven inadequate, creating an urgent need for less invasive detection methods. Among emerging solutions, noncoding RNAs (ncRNAs), particularly microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), have captured researchers' attention. These molecular elements play key roles in determining disease outcomes and treatment response in brain metastases, helping scientists better understand disease mechanisms and identify potential therapeutic interventions. Research has revealed altered patterns of ncRNA expression across various primary cancers that spread to the brain, suggesting new possibilities for treatment and prevention strategies. By examining ncRNA patterns in blood serum and cerebrospinal fluid, clinicians can potentially distinguish brain metastases from primary brain tumors without invasive procedures. The immune response within the brain microenvironment is notably influenced by ncRNAs, with miRNAs playing an especially crucial role. miRNAs show particular promise as diagnostic markers, helping to separate healthy from cancerous tissue and determine the original source of brain metastases. The therapeutic potential of miRNAs is equally significant, as targeting miRNAs could lead to more effective treatments with fewer side effects. Given the current scarcity of treatment options for brain metastases, the use of ncRNAs, especially miRNAs, represents a promising development in both diagnosis and treatment. Additional clinical research is needed to confirm the accuracy and reliability of ncRNA-based approaches, which could revolutionize how healthcare providers address this challenging aspect of cancer care and improve patient outcomes.

Suppression of breast cancer metastatic behavior by microRNAs targeting EMT transcription factors. A relevant participation of miR-196a-5p and miR-22-3p in ZEB1 expression

PURPOSE

Metastasis, the leading cause of cancer-associated deaths, is promoted by transcription factors SNAIL, SLUG, ZEB1 and TWIST through the activation of epithelial-mesenchymal transition (EMT). MicroRNAs can suppress EMT, emerging as candidate molecular biomarkers and novel therapeutic targets. Herein, we evaluated microRNAs downregulated in breast cancer (BC) tissues expressing EMT transcription factors, to find new potential regulators of EMT.

METHODS

Candidate microRNAs were selected from microarray data by their inversely correlated expression with SNAIL, SLUG, ZEB1 and TWIST, evaluated in BC tissues through immunohistochemistry. We selected eight microRNAs predicted in silico as probable modulators of SNAIL, SLUG, ZEB1 and TWIST, and validate their interaction through the 3'UTR region in luciferase reporter gene assays. MDA-MB-231 cells were transfected with selected microRNAs to perform migration, invasion and cell proliferation assays, and western blot was used to evaluate protein levels.

RESULTS

MiR-30a-5p, miR-1271-5p, miR-196a-5p, miR-202-3p, miR-210-3p, miR-22-3p and miR-331-3p decreased luciferase activity through SNAIL, SLUG, ZEB1 and/or TWIST 3'UTR. These microRNAs, including miR-34b-3p, decreased migration, invasion and cell proliferation in MDA-MB-231 cells. MiR-30a-5p, miR-202-3p and miR-22-3p decreased vimentin expression, whereas miR-196a-5p and miR-22-3p decreased endogenous ZEB1 levels. MiR-196a-5p, miR-202-3p and miR-30a-5p also decreased CCR7 expression, a chemokine receptor involved in lymph node metastasis.

CONCLUSION

microRNAs selected in this work can regulate gene expression trough 3'UTR region of EMT-transcription factors. In BC cells, miR-196a-5p and miR-22-3p decrease ZEB1 levels, being novel modulators of EMT. Also, the eight evaluated microRNAs, reduced the metastatic hallmarks in BC cells.

Association of miRNA and Bone Tumors: Future Therapeutic Inroads

Small endogenous non-coding RNA molecules known as micro-ribonucleic acids (miRNAs) control post-transcriptional gene regulation. A change in miRNA expression is related to various diseases, including bone tumors. Benign bone tumors are categorized based on matrix production and predominant cell type. Osteochondromas and giant cell tumors are among the most common bone tumors. Interestingly, miRNAs can function as either tumor suppressor genes or oncogenes, thereby determining the fate of a tumor. In the present review, we discuss various bone tumors with regard to their prognosis, pathogenesis, and diagnosis. The association between miRNAs and bone tumors, such as osteosarcoma, Ewing's sarcoma, chondrosarcoma, and giant-cell tumors, is also discussed. Moreover, miRNA may play an important role in tumor proliferation, growth, and metastasis. Knowledge of the dysregulation, amplification, and deletion of miRNA can be beneficial for the treatment of various bone cancers. The miRNAs could be beneficial for prognosis, treatment, future drug design, and treatment of resistant cases of bone cancer.

Role of miRNAs in breast cancer development and progression: Current research

Breast cancer, a complex and heterogeneous ailment impacting numerous women worldwide, persists as a prominent cause of cancer-related fatalities. MicroRNAs (miRNAs), small non-coding RNAs, have garnered significant attention for their involvement in breast cancer's progression. These molecules post-transcriptionally regulate gene expression, influencing crucial cellular processes including proliferation, differentiation, and apoptosis. This review provides an overview of the current research on the role of miRNAs in breast cancer. It discusses the role of miRNAs in breast cancer, including the different subtypes of breast cancer, their molecular characteristics, and the mechanisms by which miRNAs regulate gene expression in breast cancer cells. Additionally, the review highlights recent studies identifying specific miRNAs that are dysregulated in breast cancer and their potential use as diagnostic and prognostic biomarkers. Furthermore, the review explores the therapeutic potential of miRNAs in breast cancer treatment. Preclinical studies have shown the effectiveness of miRNA-based therapies, such as antagomir and miRNA mimic therapies, in inhibiting tumor growth and metastasis. Emerging areas, including the application of artificial intelligence (AI) to advance miRNA research and the "One Health" approach that integrates human and animal cancer insights, are also discussed. However, challenges remain before these therapies can be fully translated into clinical practice. In conclusion, this review emphasizes the significance of miRNAs in breast cancer research and their potential as innovative diagnostic and therapeutic tools. A deeper understanding of miRNA dysregulation in breast cancer is essential for their successful application in clinical settings. With continued research, miRNA-based approaches hold promise for improving patient outcomes in this devastating disease.

miR-29a-3p orchestrates key signaling pathways for enhanced migration of human mesenchymal stem cells

BACKGROUND

The homing of human mesenchymal stem cells (hMSCs) is crucial for their therapeutic efficacy and is characterized by the orchestrated regulation of multiple signaling modules. However, the principal upstream regulators that synchronize these signaling pathways and their mechanisms during cellular migration remain largely unexplored.

METHODS

miR-29a-3p was exogenously expressed in either wild-type or DiGeorge syndrome critical region 8 (DGCR8) knockdown hMSCs. Multiple pathway components were analyzed using Western blotting, immunohistochemistry, and real-time quantitative PCR. hMSC migration was assessed both in vitro and in vivo through wound healing, Transwell, contraction, and in vivo migration assays. Extensive bioinformatic analyses using gene set enrichment analysis and Ingenuity pathway analysis identified enriched pathways, upstream regulators, and downstream targets.

RESULTS

The global depletion of microRNAs (miRNAs) due to DGCR8 gene silencing, a critical component of miRNA biogenesis, significantly impaired hMSC migration. The bioinformatics analysis identified miR-29a-3p as a pivotal upstream regulator. Its overexpression in DGCR8-knockdown hMSCs markedly improved their migration capabilities. Our data demonstrate that miR-29a-3p enhances cell migration by directly inhibiting two key phosphatases: protein tyrosine phosphatase receptor type kappa (PTPRK) and phosphatase and tensin homolog (PTEN). The ectopic expression of miR-29a-3p stabilized the polarization of the Golgi apparatus and actin cytoskeleton during wound healing. It also altered actomyosin contractility and cellular traction forces by changing the distribution and phosphorylation of myosin light chain 2. Additionally, it regulated focal adhesions by modulating the levels of PTPRK and paxillin. In immunocompromised mice, the migration of hMSCs overexpressing miR-29a-3p toward a chemoattractant significantly increased.

CONCLUSIONS

Our findings identify miR-29a-3p as a key upstream regulator that governs hMSC migration. Specifically, it was found to modulate principal signaling pathways, including polarization, actin cytoskeleton, contractility, and adhesion, both in vitro and in vivo, thereby reinforcing migration regulatory circuits.

Epigenetic and Immunological Features of Bladder Cancer

Bladder cancer (BLCA) is one of the most common types of malignant tumors of the urogenital system in adults. Globally, the incidence of BLCA is more than 500,000 new cases worldwide annually, and every year, the number of registered cases of BLCA increases noticeably. Currently, the diagnosis of BLCA is based on cystoscopy and cytological examination of urine and additional laboratory and instrumental studies. However, cystoscopy is an invasive study, and voided urine cytology has a low level of sensitivity, so there is a clear need to develop more reliable markers and test systems for detecting the disease with high sensitivity and specificity. Human body fluids (urine, serum, and plasma) are known to contain significant amounts of tumorigenic nucleic acids, circulating immune cells and proinflammatory mediators that can serve as noninvasive biomarkers, particularly useful for early cancer detection, follow-up of patients, and personalization of their treatment. The review describes the most significant advances in epigenetics of BLCA.

Inhibition of miR-214 expression by small molecules alleviates head and neck cancer metastasis by targeting ALCAM/TFAP2 signaling

Predominantly, head and neck cancer (HNC) is considered a regional disease and develops in the nasal cavity, oral cavity, tongue, pharynx, and larynx. In the advanced stage, the HNC spread into distant organs. By the time head and neck cancer diagnosed, the estimated metastasis is occurred in 10-40% cases. The most important vital organs affected by distant metastasis are the lungs, bones, and liver. Despite several advancements in chemotherapies, no significant changes are observed as 5-year survival rate remains the same. Therefore, it is crucial to decipher molecular mechanisms contributing to the metastatic dissemination of head and neck cancer. Here, we tested a novel ALCAM/TFAP2 signaling by targeting multidisciplinary miR-214 expression in head and cancer cells. Our results revealed that HNC cell lines (CAL27, SCC-9, SCC-4, and SCC-25) exhibit higher expression of miR-214 compared with normal human bronchial epithelial (NHBE) cells. Higher expression of miR-214 drives the invasive potential of these cell lines. Down-regulation of miR-214 in CAL27 and SCC-9 cells either using an anti-miR-214 inhibitor (50nM) or a small molecule of green tea (EGCG) inhibited cell invasion. Treating CAL27 and SCC-9 cells with EGCG also reduces ALCAM expression, a key activated leukocyte cell adhesion molecule, potentially blocking mesenchymal phenotype. Dietary administration of EGCG significantly inhibits distant metastasis of SCC-9 cells into the lungs, liver, and kidneys. Our results also demonstrate that the reduction of miR-214 expression influences in vitro cell movement and extravasation, as evident by reduced CD31 expression, a neovascularization marker. Together, these studies suggest that identifying bioactive molecules that can inhibit distant metastasis regulated by the miRNAs may provide potent interventional approaches and a better understanding of the complex functions of miRNAs and their therapeutic targets for clinical application.

Cancer stem cells (CSCs): key player of radiotherapy resistance and its clinical significance

Cancer stem cells (CSCs) are self-renewing and slow-multiplying micro subpopulations in tumour microenvironments. CSCs contribute to cancer's resistance to radiation (including radiation) and other treatments. CSCs control the heterogeneity of the tumour. It alters the tumour's microenvironment cellular singling and promotes epithelial-to-mesenchymal transition (EMT). Current research decodes the role of extracellular vesicles (EVs) and CSCs interlink in radiation resistance. Exosome is a subpopulation of EVs and originated from plasma membrane. It is secreted by several active cells. It involed in cellular communication and messenger of healthly and multiple pathological complications. Exosomal biological active cargos (DNA, RNA, protein, lipid and glycan), are capable to transform recipient cells' nature. The molecular signatures of CSCs and CSC-derived exosomes are potential source of cancer theranostics development. This review discusse cancer stem cells, radiation-mediated CSCs development, EMT associated with CSCs, the role of exosomes in radioresistance development, the current state of radiation therapy and the use of CSCs and CSCs-derived exosomes biomolecules as a clinical screening biomarker for cancer. This review gives new researchers a reason to keep an eye on the next phase of scientific research into cancer theranostics that will help mankind.

Identification of a Five-MiRNA Expression Assay to Aid Colorectal Cancer Diagnosis

Introduction: One-third of colorectal cancer (CRC) patients present with advanced disease, and establishing control remains a challenge. Identifying novel biomarkers to facilitate earlier diagnosis is imperative in enhancing oncological outcomes. We aimed to create miRNA oncogenic signature to aid CRC diagnosis. Methods: Tumour and tumour-associated normal (TAN) were extracted from 74 patients during surgery for CRC. RNA was isolated and target miRNAs were quantified using real-time reverse transcriptase polymerase chain reaction. Regression analyses were performed in order to identify miRNA targets capable of differentiating CRC from TAN and compared with two endogenous controls (miR-16 and miR-345) in each sample. Areas under the curve (AUCs) in Receiver Operating Characteristic (ROC) analyses were determined. Results: MiR-21 (β-coefficient:3.661, SE:1.720, p = 0.033), miR-31 (β-coefficient:2.783, SE:0.918, p = 0.002), and miR-150 (β-coefficient:−4.404, SE:0.526, p = 0.004) expression profiles differentiated CRC from TAN. In multivariable analyses, increased miR-31 (β-coefficient:2.431, SE:0.715, p < 0.001) and reduced miR-150 (β-coefficient:−4.620, SE:1.319, p < 0.001) independently differentiated CRC from TAN. The highest AUC generated for miR-21, miR-31, and miR-150 in an oncogenic expression assay was 83.0% (95%CI: 61.7–100.0, p < 0.001). In the circulation of 34 independent CRC patients and 5 controls, the mean expression of miR-21 (p = 0.001), miR-31 (p = 0.001), and miR-150 (p < 0.001) differentiated CRC from controls; however, the median expression of miR-21 (p = 0.476), miR-31 (p = 0.933), and miR-150 (p = 0.148) failed to differentiate these groups. Conclusion: This study identified a five-miRNA signature capable of distinguishing CRC from normal tissues with a high diagnostic test accuracy. Further experimentation with this signature is required to elucidate its diagnostic relevance in the circulation of CRC patients.

MicroRNAs in Epithelial-Mesenchymal Transition Process of Cancer: Potential Targets for Chemotherapy

In the last decades, a kind of small non-coding RNA molecules, called as microRNAs, has been applied as negative regulators in various types of cancer treatment through down-regulation of their targets. More recent studies exert that microRNAs play a critical role in the EMT process of cancer, promoting or inhibiting EMT progression. Interestingly, accumulating evidence suggests that pure compounds from natural plants could modulate deregulated microRNAs to inhibit EMT, resulting in the inhibition of cancer development. This small essay is on the purpose of demonstrating the significance and function of microRNAs in the EMT process as oncogenes and tumor suppressor genes according to studies mainly conducted in the last four years, providing evidence of efficient target therapy. The review also summarizes the drug candidates with the ability to restrain EMT in cancer through microRNA regulation.

Current Implications of microRNAs in Genome Stability and Stress Responses of Ovarian Cancer

Genomic alterations and aberrant DNA damage signaling are hallmarks of ovarian cancer (OC), the leading cause of mortality among gynecological cancers worldwide. Owing to the lack of specific symptoms and late-stage diagnosis, survival chances of patients are significantly reduced. Poly (ADP-ribose) polymerase (PARP) inhibitors and replication stress response inhibitors present attractive therapeutic strategies for OC. Recent research has focused on ovarian cancer-associated microRNAs (miRNAs) that play significant regulatory roles in various cellular processes. While miRNAs have been shown to participate in regulation of tumorigenesis and drug responses through modulating the DNA damage response (DDR), little is known about their potential influence on sensitivity to chemotherapy. The main objective of this review is to summarize recent findings on the utility of miRNAs as cancer biomarkers, in particular, ovarian cancer, and their regulation of DDR or modified replication stress response proteins. We further discuss the suppressive and promotional effects of various miRNAs on ovarian cancer and their participation in cell cycle disturbance, response to DNA damage, and therapeutic functions in multiple cancer types, with particular focus on ovarian cancer. Improved understanding of the mechanisms by which miRNAs regulate drug resistance should facilitate the development of effective combination therapies for ovarian cancer.

Regulation of bone metastasis and metastasis suppressors by non-coding RNAs in breast cancer

Breast cancer (BC) is a critical health care issue that substantially affects women worldwide. Though surgery and chemotherapy can effectively control tumor growth, metastasis remains a primary concern. Metastatic BC cells predominantly colonize in bone, owing to their rigid osseous nutrient-rich nature. There are recently increasing studies investigating the context-dependent roles of non-coding RNAs (ncRNAs) in metastasis regulation. ncRNAs, including microRNAs, long non-coding RNAs, circular RNAs, and small interference RNAs, control the BC metastasis via altered mechanisms. Additionally, these ncRNAs have been reported in regulating a unique class of genes known as Metastatic suppressors. Metastasis suppressors like BRMS1, NM23, LIFR, and KAI1, etc., have been extensively studied for their role in inducing apoptosis, inhibiting metastasis, and maintaining homeostasis. In this review, we have emphasized the direct regulation of ncRNAs for effectively controlling the distant spread of BC. Furthermore, we have highlighted the ncRNA-mediated modulation of the metastatic suppressors, thereby delineating their indirect influence over metastasis.

miRNAs: Critical mediators of breast cancer metastatic programming

MicroRNA mediated aberrant gene regulation has been implicated in several diseases including cancer. Recent research has highlighted the role of epigenetic modulation of the complex process of breast cancer metastasis by miRNAs. miRNAs play a crucial role in the process of metastatic evolution by facilitating alterations in the phenotype of tumor cells and the tumor microenvironment that promote this process. They act as critical determinants of the multi-step progression starting from carcinogenesis all the way to organotropism. In this review, we focus on the current understanding of the compelling role of miRNAs in breast cancer metastasis.

miRNAs in Health and Disease: A Focus on the Breast Cancer Metastatic Cascade towards the Brain

MicroRNAs (miRNAs) are small non-coding RNAs that mainly act by binding to target genes to regulate their expression. Due to the multitude of genes regulated by miRNAs they have been subject of extensive research in the past few years. This state-of-the-art review summarizes the current knowledge about miRNAs and illustrates their role as powerful regulators of physiological processes. Moreover, it highlights their aberrant expression in disease, including specific cancer types and the differential hosting-metastases preferences that influence several steps of tumorigenesis. Considering the incidence of breast cancer and that the metastatic disease is presently the major cause of death in women, emphasis is put in the role of miRNAs in breast cancer and in the regulation of the different steps of the metastatic cascade. Furthermore, we depict their involvement in the cascade of events underlying breast cancer brain metastasis formation and development. Collectively, this review shall contribute to a better understanding of the uniqueness of the biologic roles of miRNAs in these processes, to the awareness of miRNAs as new and reliable biomarkers and/or of therapeutic targets, which can change the landscape of a poor prognosis and low survival rates condition of advanced breast cancer patients.

MiR-93 is related to poor prognosis in pancreatic cancer and promotes tumor progression by targeting microtubule dynamics

Biomarkers and effective therapeutic agents to improve the dismal prognosis of pancreatic ductal adenocarcinoma (PDAC) are urgently required. We aimed to analyze the prognostic value and mechanistic action of miR-93 in PDAC. Correlation of miR-93 tumor levels from 83 PDAC patients and overall survival (OS) was analyzed by Kaplan-Meier. MiR-93 depletion in PANC-1 and MIA PaCa-2 cells was achieved by CRISPR/Cas9 and miR-93 overexpression in HPDE cells by retroviral transduction. Cell proliferation, migration and invasion, cell cycle analysis, and in vivo tumor xenografts in nude mice were assessed. Proteomic analysis by mass spectrometry and western-blot was also performed. Finally, miR-93 direct binding to candidate mRNA targets was evaluated by luciferase reporter assays. High miR-93 tumor levels are significantly correlated with a worst prognosis in PDAC patients. MiR-93 abolition altered pancreatic cancer cells phenotype inducing a significant increase in cell size and a significant decrease in cell invasion and proliferation accompanied by a G2/M arrest. In vivo, lack of miR-93 significantly impaired xenograft tumor growth. Conversely, miR-93 overexpression induced a pro-tumorigenic behavior by significantly increasing cell proliferation, migration, and invasion. Proteomic analysis unveiled a large group of deregulated proteins, mainly related to G2/M phase, microtubule dynamics, and cytoskeletal remodeling. CRMP2, MAPRE1, and YES1 were confirmed as direct targets of miR-93. MiR-93 exerts oncogenic functions by targeting multiple genes involved in microtubule dynamics at different levels, thus affecting the normal cell division rate. MiR-93 or its direct targets (CRMP2, MAPRE1, or YES1) are new potential therapeutic targets for PDAC.

A novel panel of differentially-expressed microRNAs in breast cancer brain metastasis may predict patient survival

Breast cancer brain metastasis (BCBM) is an area of unmet clinical need. MicroRNAs (miRNAs) have been linked to the metastatic process in breast cancer (BC). In this study, we aim to determine differentially-expressed miRNAs utilising primary BCs that did not relapse (BCNR, n = 12), primaries that relapsed (BCR) and their paired (n = 40 pairs) brain metastases (BM) using the NanoString™ nCounter™ miRNA Expression Assays. Significance analysis of microarrays identified 58 and 11 differentially-expressed miRNAs between BCNR vs BCR and BCR vs BM respectively and pathway analysis revealed enrichment for genes involved in invasion and metastasis. Four miRNAs, miR-132-3p, miR-199a-5p, miR-150-5p and miR-155-5p, were differentially-expressed within both cohorts (BCNR-BCR, BCR-BM) and receiver-operating characteristic curve analysis (p = 0.00137) and Kaplan-Meier survival method (p = 0.0029, brain metastasis-free survival; p = 0.0007, overall survival) demonstrated their potential use as prognostic markers. Ingenuity pathway enrichment linked them to the MET oncogene, and the cMET protein was overexpressed in the BCR (p < 0.0001) and BM (p = 0.0008) cases, compared to the BCNRs. The 4-miRNAs panel identified in this study could be potentially used to distinguish BC patients with an increased risk of developing BCBM and provide potential novel therapeutic targets, whereas cMET-targeting warrants further investigation in the treatment of BCBM.

miR-30a-3p inhibits the proliferation of liver cancer cells by targeting DNMT3a through the PI3K/AKT signaling pathway

MicroRNAs (miRNAs or miRs) are crucial for normal development and maintenance of homeostasis. Dysregulated miRNA expression contributes to numerous pathological conditions, including cancer tumorigenesis. However, a limited number of studies have examined the regulatory effects of miR-30a-3p in tumorigenesis. Therefore, the present study investigated the mechanistic process of tumorigenesis in liver cancer. The results revealed a high expression of DNA methyltransferase 3a (DNMT3a) and a low expression of miR-30a-3p in HepG2 cells compared with that in the L02 cell line. A luciferase reporter assay demonstrated that DNMT3a is a direct target of miR-30a-3p. In addition, DNMT3a overexpression significantly enhanced cell proliferation, which was reversed by a miR-30a-3p mimic. Similarly, the miR-30a-3p mimic blocked DNMT3a-triggered cell cycle processes and apoptosis by attenuating active p-AKT and p-PI3K in HepG2 cells. In summary, the results of the present study demonstrate that miR-30a-3p is essential for cell proliferation regulation via its association with AKT/PI3K signaling in liver cancer. These results provide insight into the molecular mechanism by which miR-30a-3p inhibits liver cancer cell proliferation and provides a foundation for its clinical development and application.

Circulating microRNA-301 as a promising diagnostic biomarker of hepatitis C virus-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a serious consequence of persistent hepatitis C virus (HCV) infection and represents one of the most aggressive neoplasms globally. The implication of microRNA-301 (miR-301) in the initiation and progression of different types of cancers has been proved. We aimed to assess circulating microRNA-301 as possible biomarker for the early detection of HCC in patients with chronic HCV infection. miR-301 expression levels were estimated in plasma samples of 42 patients with newly diagnosed HCV-related HCC, 48 chronically HCV infected patients with liver cirrhosis and 40 healthy individuals by reverse transcription-quantitative polymerase chain reaction technique. In comparison with chronically HCV infected patients and healthy controls, miR-301 expression levels were significantly increased in HCC patients (P < 0.001). miR-301 levels distinguished HCC patients from chronic HCV patients, with area under the receiver-operating characteristic curve of 0.89 (95% CI 0.82-0.96), the sensitivity and the specificity were 78.57% and 89.58% respectively. Moreover, miR-301 levels were significantly linked with tumor size (P = 0.014), serum levels of alpha-fetoprotein (AFP) (P = 0.028) and Barcelona Clinic Liver Cancer (BCLC) score (P = 0.003). These results reveal that miR-301 can serve as a promising non-invasive biomarker for diagnosis of HCC in chronically HCV infected patients.

Integrated copy number and miRNA expression analysis in triple negative breast cancer of Latin American patients

Triple negative breast cancer (TNBC), a clinically aggressive breast cancer subtype, affects 15-35% of women from Latin America. Using an approach of direct integration of copy number and global miRNA profiling data, performed simultaneously in the same tumor specimens, we identified a panel of 17 miRNAs specifically associated with TNBC of ancestrally characterized patients from Latin America, Brazil. This panel was differentially expressed between the TNBC and non-TNBC subtypes studied (p ≤ 0.05, FDR ≤ 0.25), with their expression levels concordant with the patterns of copy number alterations (CNAs), present mostly frequent at 8q21.3-q24.3, 3q24-29, 6p25.3-p12.2, 1q21.1-q44, 5q11.1-q22.1, 11p13-p11.2, 13q12.11-q14.3, 17q24.2-q25.3 and Xp22.33-p11.21. The combined 17 miRNAs presented a high power (AUC = 0.953 (0.78-0.99);95% CI) in discriminating between the TNBC and non-TNBC subtypes of the patients studied. In addition, the expression of 14 and 15 of the 17miRNAs was significantly associated with tumor subtype when adjusted for tumor stage and grade, respectively. In conclusion, the panel of miRNAs identified demonstrated the impact of CNAs in miRNA expression levels and identified miRNA target genes potentially affected by both CNAs and miRNA deregulation. These targets, involved in critical signaling pathways and biological functions associated specifically with the TNBC transcriptome of Latina patients, can provide biological insights into the observed differences in the TNBC clinical outcome among racial/ethnic groups, taking into consideration their genetic ancestry.

MiR-16-5p inhibits breast cancer by reducing AKT3 to restrain NF-κB pathway

Background: Breast cancer endangers the life of women and has become the major cause of deaths among them. MiRNAs are found to exert a regulatory effect on the migration, proliferation and apoptosis of breast cancer cells. This research aims at investigating the miR-16-5p expression and its effect on the pathogenesis of breast cancer. Methods: Their clinical data were analyzed with qRT-PCR. CCK8, EdU and Transwell was performed to explore the function of miR-16-5p in cell migration and proliferation of breast cancer cells. Dual-luciferase reporter assay, immunohistochemistry and Western blotting were carried out to explore the relation between miR-16-5p and AKT3. Results: It was discovered that miR-16-5p was lowly expressed in breast cancer patients. Meanwhile, breast cancer patients with under-expressed miR-16-5p had a lower survival rate than those with highly expressed miR-16-5p. Furthermore, decreased miR-16-5p in cell and animal models enhanced migration and proliferation of breast cancer cells, stimulated cell cycle and reduced cell apoptosis. Finally, we found miR-16-5p restrained the NF-κB pathway and decreased AKT3 gene, thereby suppressing the breast cancer development. Conclusion: It can be seen that miR-16-5p exhibits a low expression in breast cancer tissues, which can inhibit breast cancer by restraining the NF-κB pathway and elevating reducing AKT3.

miR-21 promotes non-small cell lung cancer cells growth by regulating fatty acid metabolism

Background

Lung cancer is one of the most common malignant tumors worldwide. CD36 is a receptor for fatty acids and plays an important role in regulating fatty acid metabolism, which is closely related to tumorigenesis and development. The regulation of miR-21 and its role in tumorigenesis have been extensively studied in recent years. However, the relationship between miR-21 and CD36 regulated fatty acid metabolism in human non-small cell lung cancer remains unknown.

Methods

In this study, lentivirus transfection, qRT-PCR, cell migration, immunofluorescence, and western blot were used to examine the relationship between miR-21 and CD36 regulated fatty acid metabolism and the regulation role of miR-21 in human non-small cell lung cancer.

Results

This study demonstrated that up-regulation of miR-21 promoted cell migration and cell growth in human non-small cell lung cancer cells. Moreover, the intracellular contents of lipids including cellular content of phospholipids, neutral lipids content, cellular content of triglycerides were significantly increased following miR-21 mimic treatment compared with control, and the levels of key lipid metabolic enzymes FASN, ACC1 and FABP5 were obviously enhanced in human non-small cell lung cancer cells. Furthermore, down-regulation of CD36 suppressed miR-21 regulated cell growth, migration and intracellular contents of lipids in human non-small cell lung cancer cells, which suggested that miR-21 promoted cell growth and migration of human non-small cell lung cancer cells through CD36 mediated fatty acid metabolism. Inhibition of miR-21 was revealed to inhibit cell growth, migration, intracellular contents of lipids, and CD36 protein expression level in human non-small cell lung cancer cells. In addition, PPARGC1B was a direct target of miR-21, and down-regulation of PPARGC1B reversed the inhibition of CD36 expression induced by miR-21 inhibitor.

Conclusions

These results explored the mechanism of miR-21 promoted non-small cell lung cancer and might provide a novel therapeutic method in treating non-small cell lung cancer in clinic.

MicroRNA-652 suppresses malignant phenotypes in glioblastoma multiforme via FOXK1-mediated AKT/mTOR signaling pathway

Purpose

An increasing number of studies have documented that dysregulation of microRNAs (miRNAs) is common in glioblastoma multiforme (GBM). miR-652 is aberrantly expressed in various human cancers and plays important roles in numerous cancer-related processes. However, the expression profiles and potential roles of miR-652 in GBM remain largely unknown.

Patients and methods

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to determine miR-652 expression in GBM tissues and cell lines. The effects of miR-652 upregulation on GBM cell proliferation, clone formation, apoptosis, migration and invasion were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, clone formation, flow cytometry and Transwell^® migration and invasion assays, respectively. In vivo xenotransplantation was utilized to determine the effect of miR-652 on GBM tumor growth in vivo. Of note, the molecular mechanisms underlying the tumor-suppressing activity of miR-652 upregulation in GBM cells were also investigated using a series of experiments, including bioinformatics analysis, luciferase reporter assay, RT-qPCR and Western blot analysis.

Results

miR-652 expression was considerably downregulated in GBM tissues and cell lines. Low miR-652 expression was strongly correlated with Karnofsky performance score and tumor size. Overall survival duration was shorter in GBM patients with low miR-652 expression than in those with high miR-652 expression. miR-652 resumption considerably suppressed the proliferation, clone formation, migration, and invasion and promoted the apoptosis of GBM cells in vitro. In addition, forkhead-box k1 (FOXK1) was demonstrated as the direct target gene of miR-652 in GBM cells. FOXK1 downregulation led to a tumor-suppressing activity similar to that of miR-652 upregulation. Restoration of FOXK1 expression partially neutralized the influence of miR-652 overexpression on GBM cells. Furthermore, ectopic miR-652 expression deactivated the AKT/mTOR pathway in GBM cells via FOXK1 regulation. Moreover, miR-652 impaired GBM tumor growth in vivo, probably caused by miR-652-mediated suppression of FOXK1/AKT/mTOR signaling.

Conclusion

miR-652 inhibits FOXK1 and deactivates the AKT/mTOR pathway, thereby resulting in the suppression of malignant phenotypes of GBM cells in vitro and in vivo.

Relationship among porcine lncRNA TCONS_00010987, miR-323, and leptin receptor based on dual luciferase reporter gene assays and expression patterns

Objective

Considering the physiological and clinical importance of leptin receptor (LEPR) in regulating obesity and the fact that porcine LEPR expression is not known to be controlled by lncRNAs and miRNAs, we aim to characterize this gene as a potential target of SSC-miR-323 and the lncRNA TCONS_00010987.

Methods

Bioinformatics analyses revealed that lncRNA TCONS_00010987 and LEPR have SSC-miR-323-binding sites and that LEPR might be a target of lncRNA TCONS_00010987 based on cis prediction. Wild-type and mutant TCONS_00010987-target sequence fragments and wild-type and mutant LEPR 3′-UTR fragments were generated and cloned into pmiR-RB-REPORT^TM-Control vectors to construct respective recombinant plasmids. HEK293T cells were co-transfected with the SSC-miR-323 mimics or a negative control with constructs harboring the corresponding binding sites and relative luciferase activities were determined. Tissue expression patterns of lncRNA TCONS_00010987, SSC-miR-323, and LEPR in Anqing six-end-white (AQ, the obese breed) and Large White (LW, the lean breed) pigs were detected by real-time quantitative polymerase chain reaction; backfat expression of LEPR protein was detected by western blotting.

Results

Target gene fragments were successfully cloned, and the four recombinant vectors were constructed. Compared to the negative control, SSC-miR-323 mimics significantly inhibited luciferase activity from the wild-type TCONS_00010987-target sequence and wild-type LEPR-3′-UTR (p<0.01 for both) but not from the mutant TCONS_00010987-target sequence and mutant LEPR-3′-UTR (p>0.05 for both). Backfat expression levels of TCONS_ 00010987 and LEPR in AQ pigs were significantly higher than those in LW pigs (p<0.01), whereas levels of SSC-miR-323 in AQ pigs were significantly lower than those in LW pigs (p<0.05). LEPR protein levels in the backfat tissues of AQ pigs were markedly higher than those in LW pigs (p<0.01).

Conclusion

LEPR is a potential target of SSC-miR-323, and TCONS_00010987 might act as a sponge for SSC-miR-323 to regulate LEPR expression.

Circulating microRNAs miR-331 and miR-195 differentiate local luminal a from metastatic breast cancer

BACKGROUND

Breast cancer is the leading cause of cancer related death in women, with metastasis the principle cause of mortality. New non-invasive prognostic markers are needed for the early detection of metastasis, facilitating treatment decision optimisation. MicroRNA (miRNA) are small, non-coding RNAs regulating gene expression and involved in many cellular processes, including metastasis. As biomarkers, circulating miRNAs (in blood) hold great promise for informing diagnosis or monitoring treatment responses.

METHODS

Plasma extracted RNA from age matched local Luminal A (n = 4) or metastatic disease (n = 4) were profiled using Next Generation Sequencing. Selected differentially expressed miRNA were validated on a whole blood extracted miRNA cohort [distant metastatic disease (n = 22), local disease (n = 31), healthy controls (n = 21)]. Area Under the Curve (AUC) in Receiver Operating Characteristic (ROC) analyses was performed.

RESULTS

Of 4 miRNA targets tested (miR-181a, miR-329, miR-331, miR-195), mir-331 was significantly over-expressed in patients with metastatic disease, compared to patients with local disease (p < 0.001) or healthy controls (p < 0.001). miR-195 was significantly under-expressed in patients with metastatic disease, compared to patients with local disease (p < 0.001) or healthy controls (p = 0.043). In combination, miR-331 and miR-195 produced an AUC of 0.902, distinguishing metastatic from local breast cancer.

CONCLUSIONS

We identified and validated two circulating miRNAs differentiating local Luminal A breast cancers from metastatic breast cancers. Further investigation will reveal the molecular role of these miRNAs in metastasis, and determine if they are subtype specific. This work demonstrates the ability of circulating miRNA to identify metastatic disease, and potentially inform diagnosis or treatment effectiveness.

MicroRNAs as Potential Targets for Therapeutic Intervention With Metastasis of Non-small Cell Lung Cancer

The death toll of non-small cell lung cancer (NSCLC) patients is primarily due to metastases, which are poorly amenable to therapeutic intervention. In this review we focus on miRs associated with metastasis of NSCLC as potential new targets for anti-metastatic therapy. We discuss miRs validated as therapeutic targets by in vitro data, identification of target(s) and pathway(s) and in vivo efficacy data in at least one clinically-relevant metastasis-related model. A few of the discussed miRs correlate with the clinical status of NSCLC patients. Using miRs as therapeutic agents has the advantage that targeting a single miR can potentially interfere with several metastatic pathways. Depending on their mode of action, the corresponding miRs can be up- or down-regulated compared to normal matching tissues. Here, we describe therapeutic approaches for reconstitution therapy and miR inhibition, general principles of anti-metastatic therapy as well as current technical pitfalls.

Downregulation of microRNA-374a predicts poor prognosis in human glioma

Certain microRNAs (miRNAs/miRs) may be used as prognostic biomarkers in various types of cancer. The purpose of the present study was to identify miRNAs that were abnormally expressed in glioma of different grades, and to evaluate their clinical implications in patients with glioma. The differentially expressed miRNAs were evaluated from the expression profiles of six glioma tissues (three low-grade and three high-grade gliomas) determined using a microarray platform. Reverse transcription-quantitative polymerase chain reaction analysis was used to further verify the aberrant expression of the candidate miRNA in a set of 42 patients and 5 healthy controls. The miRNA target genes were predicted and the protein-protein interaction network was generated; furthermore, functional enrichment analysis of the target genes in Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways was performed. Kaplan-Meier curves and Log-rank analysis, as well as multivariate Cox regression analysis were performed to assess the association of the candidate miRNA with patient survival. A total of 15 differentially expressed miRNAs, including 13 downregulated and 2 upregulated miRNAs, were identified by comparison of low-grade and high-grade glioma tissues. The miR-374a expression of high-grade gliomas was significantly lower than that of low-grade gliomas (fold change, -4.43; P=0.027). The expression levels of miR-374a gradually decreased with the increase of the pathological grade of glioma. Pearson's Chi-square test was used to determine the association of miR-374a expression with several clinicopathological factors. Furthermore, low expression of miR-374a was determined to be an independent prognostic marker and that it was significantly associated with overall survival (P=0.0213). GO and KEGG pathway analysis revealed that the target genes of miR-374a may be involved in the regulation of the RNA polymerase II promoter and mTOR signaling pathway. The four hub genes (CCND1, SP1, CDK4, CDK6) were also identified by PPI network analysis. In conclusion, the present study indicated that miR-374a may be used as a promising prognostic biomarker for the screening of high-risk populations and for the assessment of the prognosis of patients with glioma.

mRNA and miRNA expression profiling of follicular variant of papillary thyroid carcinoma with and without distant metastases

Follicular Variant of Papillary Thyroid Carcinoma (FVPTC) is usually associated with a good outcome. Nevertheless, in rare cases, it develops distant metastases (1-9%). Our goal was to investigate whether mRNA and miRNA expression profiles may help distinguish between metastatic versus non-metastatic FVPTCs. Twenty-four primary FVPTCs, 12 metastatic and 12 non-metastatic, with similar clinicopathological features were selected and analyzed by nanoString nCounter technology using two distinct panels for expression analysis of 740 mRNA and 798 miRNAs. Data analysis was performed using the nanoString nSolver 3.0 software. Forty-seven mRNA and 35 miRNAs were differentially expressed between the two groups. Using these mRNA and miRNAs, metastatic and non-metastatic FVPTCs were clearly divided into two distinct clusters. Our results indicate that FVPTCs with metastatic abilities have different expression profiles compared to the non-metastatic. A prospective validation is needed to evaluate the usefulness of this molecular approach in the early identification of high-risk FVPTCs.

MicroRNA replacement therapy in cancer

Despite the recent progress in cancer management approaches, the mortality rate of cancer is still growing and there are lots of challenges in the clinics in terms of novel therapeutics. MicroRNAs (miRNA) are regulatory small noncoding RNAs and are already confirmed to have a great role in regulating gene expression level by targeting multiple molecules that affect cell physiology and disease development. Recently, miRNAs have been introduced as promising therapeutic targets for cancer treatment. Regulatory potential of tumor suppressor miRNAs, which enables regulation of entire signaling networks within the cells, makes them an interesting option for developing cancer therapeutics. In this regard, over recent decades, scientists have aimed at developing powerful and safe targeting approaches to restore these suppressive miRNAs in cancerous cells. The present review summarizes the function of miRNAs in tumor development and presents recent findings on how miRNAs have served as therapeutic agents against cancer, with a special focus on tumor suppressor miRNAs (mimics). Moreover, the latest investigations on the therapeutic strategies of miRNA delivery have been presented.

Hsa-let-7g promotes osteosarcoma by reducing HOXB1 to activate NF-kB pathway

MicroRNA (miRNA) is known to be involved in regulating the proliferation, migration and apoptosis of cancer cells in osteosarcoma. In this study, We aim to explore the expression of hsa-let-7 g and its role in pathogenesis of osteosarcoma. By analyzing clinical data. We found high expression of hsa-let-7 g in patients with osteosarcoma. The patients with higher expression of hsa-let-7 g showed poorer prognosis and lower survival rate. After downregulation of hsa-let-7 g in cell model and animal model, we found that with downregulation of hsa-let-7 g, the proliferation of osteosarcoma cells was significantly reduced, the level of migration and invasion was down-regulated, the cell cycle was inhibited, and cell apoptosis was increased. Through Dual Luciferase Reporter, immunohistochemistry, western blot and other experiments, it was found that hsa-let-7 g down-regulated HOXB1 gene and activated NF-kB pathway to promote the development of osteosarcoma. In conclusion, hsa-let-7 g is highly expressed in osteosarcoma tissues, and high expression of hsa-let-7 g can promote the occurrence of osteosarcoma by down-regulating HOXB1 and activating NF-kB pathway.

Exosomal microRNAs as potential biomarkers for cancer cell migration and prognosis in hepatocellular carcinoma patient-derived cell models

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, and current treatments exhibit limited efficacy against advanced HCC. The majority of cancer-related deaths are caused by metastasis from the primary tumor, which indicates the importance of identifying clinical biomarkers for predicting metastasis and indicating prognosis. Patient-derived cells (PDCs) may be effective models for biomarker identification. In the present study, a wound healing assay was used to obtain 10 fast-migrated and 10 slow-migrated PDC cultures from 36 HCC samples. MicroRNA (miRNA) signatures in PDCs and PDC-derived exosomes were profiled by microRNA-sequencing. Differentially expressed miRNAs between the low- and fast-migrated groups were identified and further validated in 372 HCC profiles from The Cancer Genome Atlas (TCGA). Six exosomal miRNAs were identified to be differentially expressed between the two groups. In the fast-migrated group, five miRNAs (miR-140-3p, miR-30d-5p, miR-29b-3p, miR-130b-3p and miR-330-5p) were downregulated, and one miRNA (miR-296-3p) was upregulated compared with the slow-migrated group. Pathway analysis demonstrated that the target genes of the differentially expressed miRNAs were significantly enriched in the 'focal adhesion' pathway, which is consistent with the roles of these miRNAs in tumor metastasis. Three miRNAs, miR-30d, miR-140 and miR-29b, were significantly associated with patient survival. These findings indicated that these exosomal miRNAs may be candidate biomarkers for predicting HCC cell migration and prognosis and may guide the treatment of advanced HCC.

Sec23a mediates miR-200c augmented oligometastatic to polymetastatic progression

Background

Cancer treatment is based on tumor staging. Curative intent is only applied to localized tumors. Recent studies show that oligometastatic patients who have limited number of metastases may benefit from metastasis-directed local treatments to achieve long-term survival. However, mechanisms underlying oligometastatic to polymetastatic progression remains elusive.

Methods

The effects of miR-200c and Sec23a on tumor metastasis were verified both in vitro and in vivo. The secretome changes were detected by mass spectrometry.

Findings

We established a pair of homologous lung-metastasis derived oligometastatic and polymetastatic cell lines from human melanoma cancer cell line M14. Using the two cell lines, we have identified Sec23a, a gene target of miR-200c, suppresses miR-200c augmented oligometastatic to polymetastatic progression via its secretome. Firstly, miR-200c over-expression and Sec23a interference accelerated oligometastatic to polymetatic progression. Secondly, Sec23a functions downstream of miR-200c. Thirdly, mass spectrometric analysis of the secretory protein profile suggests that Sec23a-dependent secretome may impact metastatic colonization by modifying tumor microenvironment. Fourthly, the survival analysis using The Cancer Genome Atlas database shows Sec23a as a favorable prognostic marker for skin cutaneous melanoma, supporting the clinical relevance of our findings.

Interpretation

The finding that Sec23a is a suppressor of oligometastatic to polymetastatic progression has clinical implications. First, it provides a new theoretical framework for the development of treatments that prevent oligometastasis to polymetastasis. Second, Sec23a may be used as a favorable prognostic marker for the selection of patients with stable oligometastatic disease for oligometastasis-based local therapies of curative intent.

Fund

National Natural Science Foundations of China.

MicroRNA Microarray Profiling during Megakaryocyte Differentiation of Cord Blood CD133+ Hematopoietic Stem Cells

Objective

In order to clarify the role of microRNAs (miRNA) in megakaryocyte differentiation, we ran a microRNA microarray experiment to measure the expression level of 961 human miRNA in megakaryocytes differentiated from human umbilical cord blood CD133+ cells.

Materials and Methods

In this experimental study, human CD133+ hematopoietic stem cells were collected from three human umbilical cord blood (UCB) samples, and then differentiated to the megakaryocytic lineage and characterized by flow cytometry, CFU-assay and ploidy analysis. Subsequently, microarray analysis was undertaken followed by quantitative polymerase chain reaction (qPCR) to validate differentially expressed miRNA identified in the microarray analysis.

Results

A total of 10 and 14 miRNAs were upregulated (e.g. miR-1246 and miR-148-a) and down-regulated (e.g. miR- 551b and miR-10a) respectively during megakaryocyte differentiation, all of which were confirmed by qPCR. Analysis of targets of these miRNA showed that the majority of targets are transcription factors involved in megakaryopoiesis.

Conclusion

We conclude that miRNA play an important role in megakaryocyte differentiation and may be used as targets to change the rate of differentiation and further our understanding of the biology of megakaryocyte commitment.

MicroRNAs and miRceptors: a new mechanism of action for intercellular communication

MicroRNAs (miRs) are small non-coding RNAs (ncRNAs) that control the expression of target genes by modulating (usually inhibiting) their translation into proteins. This 'traditional' mechanism of action of miRs has been recently challenged by new discoveries pointing towards a role of miRs as 'hormones', capable of binding to proteic receptors (miRceptors) and triggering their downstream signalling pathways. These findings harbour particular significance within the tumour microenvironment (TME), defined as the variety of non-cancerous cells surrounding cancer cells, but are relevant also for other diseases. In recent years it has become clearer that the TME does not passively assist the growth of cancer cells but contributes to its biology. Some of the mediators of the intercellular communication between cancer cells and TME are miRs shuttled within exosomes, a subtype of cellular released extracellular vesicles. This article will highlight the most recent findings on the biological implications of miR-miRceptor interactions for the biology of the TME and other diseases, and will provide some perspectives on the future development of this fascinating research.This article is part of the discussion meeting issue 'Extracellular vesicles and the tumour microenvironment'.

MiR-652-3p is upregulated in non-small cell lung cancer and promotes proliferation and metastasis by directly targeting Lgl1

Our previous study found that miR-652-3p is markedly upregulated in the serum of patients with NSCLC and suggesting that miR-652-3p is a potential biomarker for the early diagnosis of NSCLC. In this study, we detected the expression of miR-652-3p in NSCLC tumor tissues and cell lines and investigated the effect of miR-652-3p on the proliferation and metastasis of NSCLC cells. Our results showed that the expression of miR-652-3p was significantly upregulated in tumor tissues of 50 patients with NSCLC, and it was significantly higher in patients with positive lymph node metastasis, advanced TNM stage and poor prognosis. Using functional analyses by overexpressing or suppressing miR-652-3p in NSCLC cells, we demonstrated that miR-652-3p promoted cell proliferation, migration, invasion and inhibited cell apoptosis. Moreover, the lethal(2) giant larvae 1 (Lgl1) was identified as a direct and functional target of miR-652-3p. Overexpression or knockdown of miR-652-3p led to decreased or increased expression of Lgl1 protein, and the binding site mutation of LLGL1 3'UTR abrogated the responsiveness of the luciferase reporters to miR-652-3p. Overexpression of Lgl1 partially attenuated the function of miR-652-3p. Collectively, these results revealed that miR-652-3p execute a tumor-promoter function in NSCLC through direct binding and regulating the expression of Lgl1.

miR-17-5p Regulates Differential Expression of NCOA3 in Pig Intramuscular and Subcutaneous Adipose Tissue

Fat distribution affects economic value in pork production. Intramuscular adipose tissue (IMAT) improves meat quality, whereas subcutaneous adipose tissue (SCAT) is usually regarded as waste. In the present study, we analyzed IMAT/SCAT (I/S) ratios in each pig. Individuals selected from a population of 1200 Suhuai pigs were divided into two cohorts; those with high I/S ratios and those with low I/S ratios, and correlations between nuclear Receptor Co-activator 3 (NCOA3), a critical gene involved in regulating fat accumulation, and fat distribution were investigated. The ratio of IMAT NCOA3 to SCAT NCOA3 expression levels (NCOA3_I/NCOA3_S) was higher in the high I/S group compared with the low I/S group. The NCOA3 expression level in fat tissue was positively correlated with fat deposition. miR-17-5p was identified as a putative regulator of NCOA3 based on bioinformatics prediction analysis followed by gene expression analysis. The miR-17-5p_I/miR-17-5p_S ratio was negatively correlated with the NCOA3_I/NCOA3_S ratio. The predicted relationship between miR-17-5p and NCOA3 was further verified by dual luciferase activity assays, qPCR, and western blots. Overexpression of miR-17-5p in intramuscular preadipocytes inhibited NCOA3 expression and reduced preadipocyte differentiation. FABP4 and PPARG expression were also significantly decreased, as was triglyceride content. Meanwhile, knockdown of miR-17-5p significantly increased NCOA3 expression and promoted intramuscular preadipocyte differentiation. Based on these results, we propose that differential expression of NCOA3 in pig intramuscular and subcutaneous adipose tissue is regulated by miR-17-5p.

Melatonin suppresses hepatocellular carcinoma progression via lncRNA-CPS1-IT-mediated HIF-1α inactivation

Melatonin is the primary pineal hormone that relays light/dark cycle information to the circadian system. It was recently reported to exert intrinsic antitumor activity in various cancers. However, the regulatory mechanisms underlying the antitumor activity of melatonin are poorly understood. Moreover, a limited number of studies have addressed the role of melatonin in hepatocellular carcinoma (HCC), a major life-threatening malignancy in both sexes in Taiwan. In this study, we investigated the antitumor effects of melatonin in HCC and explored the regulatory mechanisms underlying these effects. We observed that melatonin significantly inhibited the proliferation, migration, and invasion of HCC cells and significantly induced the expression of the transcription factor FOXA2 in HCC cells. This increase in FOXA2 expression resulted in upregulation of lncRNA-CPS1 intronic transcript 1 (CPS1-IT1), which reduced HIF-1α activity and consequently resulted in the suppression of epithelial-mesenchymal transition (EMT) progression and HCC metastasis. Furthermore, the results of the in vivo experiments confirmed that melatonin exerts tumor suppressive effects by reducing tumor growth. In conclusion, our findings suggested that melatonin inhibited HCC progression by reducing lncRNA-CPS1-IT1-mediated EMT suppression and indicated that melatonin could be a promising treatment for HCC.

Cleavage and polyadenylation: Ending the message expands gene regulation

Cleavage and polyadenylation (pA) is a fundamental step that is required for the maturation of primary protein encoding transcripts into functional mRNAs that can be exported from the nucleus and translated in the cytoplasm. 3'end processing is dependent on the assembly of a multiprotein processing complex on the pA signals that reside in the pre-mRNAs. Most eukaryotic genes have multiple pA signals, resulting in alternative cleavage and polyadenylation (APA), a widespread phenomenon that is important to establish cell state and cell type specific transcriptomes. Here, we review how pA sites are recognized and comprehensively summarize how APA is regulated and creates mRNA isoform profiles that are characteristic for cell types, tissues, cellular states and disease.

Upregulation of microRNA-137 expression by Slug promotes tumor invasion and metastasis of non-small cell lung cancer cells through suppression of TFAP2C

The epithelial-mesenchymal transition (EMT) regulator, Slug, plays multifaceted roles in controlling lung cancer progression, but its downstream targets and mechanisms in promoting lung cancer progression have not been well defined. In particular, the miRNAs downstream of Slug in non-small cell lung cancer (NSCLC) remain undetermined. Here, we report that miR-137 is downstream of the EMT regulator, Slug, in lung cancer cells. Slug binds directly to the E-box of the miR-137 promoter and up-regulates its expression in lung cancer cells. Knockdown of miR-137 abolished Slug-induced cancer invasion and migration, whereas upregulation of miR-137 was found to trigger lung cancer cell invasion and progression by direct suppressing TFAP2C (transcription factor AP-2 gamma). Clinical data showed that lung adenocarcinoma patients with low-level expression of Slug and miR-137 but high-level expression of TFAP2C experienced significantly better survival. miR-137 is a Slug-induced miRNA that relays the pro-metastatic effects of Slug by targeting TFAP2C. Our findings add new components to the Slug-mediated regulatory network in lung cancer, and suggest that Slug, miR-137, and TFAP2C may be useful prognostic markers in lung adenocarcinoma.

microRNAs: Emerging players in oral cancers and inflammatory disorders

Association of oral diseases and disorders with altered microRNA profiles is firmly recognized. These evidences support the potential use of microRNAs as therapeutic tools for diagnosis, prognosis, and treatment of various diseases. In this review, we highlight the association of altered microRNA signatures in oral cancers and oral inflammatory diseases. Advances in our ability to detect microRNAs in human sera and saliva further highlight their clinical value as potential biomarkers. We have discussed key mechanisms underlying microRNA dysregulation in pathological conditions. The use of microRNAs in diagnostics and their potential therapeutic value in the treatment of oral diseases are reviewed.

MicroRNA-211 expression is down-regulated and associated with poor prognosis in human glioma

Accumulating evidence has supported the role of microRNAs in the initiation and development of malignant tumors. MicroRNA-211 (miR-211), which was reported to involve in diverse physiological activities in several cancers, was investigated for its expression in human glioma and adjacent normal brain tissues, as well as its correlation with patient prognosis. Glioma tissues and adjacent normal brain tissues were obtained from 82 patients who underwent surgical resection, and quantitative real-time polymerase chain reaction was performed to assess the expression level of miR-211. Here, we found that miR-211 was significantly decreased in glioma tissues compared with adjacent normal brain tissues (glioma, 3.52 ± 0.14 vs. normal, 4.96 ± 0.17, p < 0.001), and inversely associated with ascending WHO classification (grade III-IV, 3.16 ± 0.21 vs. grade I-II, 4.22 ± 0.26, p < 0.001). Then, the correlation of miR-211 with clinicopathological factors was investigated by Pearson's Chi square test, indicating that miR-211 might be a potential biomarker to predict the malignant status of glioma. Further, Kaplan-Meier curves with log-rank analysis were carried out to determine the relationship between miR-211 expression level and the overall survival rate of glioma patients. Our data showed that there was a close correlation between down-regulated miR-211 and shorter survival time in 82 patients (p = 0.026). Finally, the multivariate Cox regression analysis indicated that WHO grade (HR = 2.437, 95% CI 1.251-4.966, p = 0.007), KPS (HR = 2.215, 95% CI 1.168-4.259, p = 0.016), and miR-211 expression level (HR = 3.614, 95% CI 2.152-6.748, p < 0.001) were considered as independent risk factors for glioma prognosis. These results suggested that lower miR-211 expression might be a marker for poor prognosis of glioma patients.

Role of miRNAs in human cancer metastasis: Implications for therapeutic intervention

Metastasis is the spread and growth of localized cancer to new locations in the body and is considered the main cause of cancer-related deaths. Metastatic cancer cells display distinct genomic and epigenomic profiles and almost universally an aggressive pathophysiology. A better understanding of the molecular mechanisms and regulation of metastasis, including how metastatic tumors grow and survive in the nascent niche and the interactions of the emergent metastatic cancer cells within the local microenvironment may provide tools to design strategies to restrict metastatic dissemination. Aberrant microRNAs (miRNA) expression has been reported in metastatic cancer cells. MicroRNAs are known to regulate divergent and/or convergent metastatic gene pathways including activation of reprogramming switches during metastasis. An in-depth understanding of role of miRNAs in the metastatic cascade may lead to the identification of novel targets for anti-metastatic therapeutics as well as potential candidate miRNAs for cancer treatment. This review primarily focuses on the role of miRNAs in the mechanisms of cancer metastasis as well as implications for metastatic cancer treatment.

Induction of metastasis, cancer stem cell phenotype, and oncogenic metabolism in cancer cells by ionizing radiation

Radiation therapy is one of the major tools of cancer treatment, and is widely used for a variety of malignant tumours. Radiotherapy causes DNA damage directly by ionization or indirectly via the generation of reactive oxygen species (ROS), thereby destroying cancer cells. However, ionizing radiation (IR) paradoxically promotes metastasis and invasion of cancer cells by inducing the epithelial-mesenchymal transition (EMT). Metastasis is a major obstacle to successful cancer therapy, and is closely linked to the rates of morbidity and mortality of many cancers. ROS have been shown to play important roles in mediating the biological effects of IR. ROS have been implicated in IR-induced EMT, via activation of several EMT transcription factors—including Snail, HIF-1, ZEB1, and STAT3—that are activated by signalling pathways, including those of TGF-β, Wnt, Hedgehog, Notch, G-CSF, EGFR/PI3K/Akt, and MAPK. Cancer cells that undergo EMT have been shown to acquire stemness and undergo metabolic changes, although these points are debated. IR is known to induce cancer stem cell (CSC) properties, including dedifferentiation and self-renewal, and to promote oncogenic metabolism by activating these EMT-inducing pathways. Much accumulated evidence has shown that metabolic alterations in cancer cells are closely associated with the EMT and CSC phenotypes; specifically, the IR-induced oncogenic metabolism seems to be required for acquisition of the EMT and CSC phenotypes. IR can also elicit various changes in the tumour microenvironment (TME) that may affect invasion and metastasis. EMT, CSC, and oncogenic metabolism are involved in radioresistance; targeting them may improve the efficacy of radiotherapy, preventing tumour recurrence and metastasis. This study focuses on the molecular mechanisms of IR-induced EMT, CSCs, oncogenic metabolism, and alterations in the TME. We discuss how IR-induced EMT/CSC/oncogenic metabolism may promote resistance to radiotherapy; we also review efforts to develop therapeutic approaches to eliminate these IR-induced adverse effects.

MiR-200c promotes bladder cancer cell migration and invasion by directly targeting RECK

Background

Increasing evidence suggests that the dysregulation of certain microRNAs plays an important role in tumorigenesis and metastasis. MiR-200c exhibits a disordered expression in many tumors and presents dual roles in bladder cancer (BC). Therefore, the definite role of miR-200c in BC needs to be investigated further.

Materials and methods

Quantitative reverse transcription polymerase chain reaction was used to assess miR-200c expression. Cell invasion and migration were evaluated using wound healing and transwell assays. The luciferase reporter assay was used to identify the direct target of miR-200c. The expression of reversion-inducing cysteine-rich protein with kazal motifs (RECK) in BC tissues and adjacent nontumor tissues, as well as in BC cell lines, was detected through quantitative reverse transcription polymerase chain reaction, Western blot assay, and immunohistochemistry.

Results

The miR-200c expression was significantly upregulated in the BC tissues compared with the adjacent nontumor tissues. The downregulation of miR-200c significantly inhibited cell migration and invasion in the BC cell lines. The luciferase reporter assay showed that RECK was a direct target of miR-200c. The knockdown of RECK in the BC cell lines treated with anti-miR-200c elevated the previously attenuated cell migration and invasion.

Conclusion

Our findings indicated that miR-200c functions as oncogenes in BC and may provide a novel therapeutic strategy for the treatment of BC.

Ursolic acid induced anti-proliferation effects in rat primary vascular smooth muscle cells is associated with inhibition of microRNA-21 and subsequent PTEN/PI3K

This study focused on the anti-proliferation effects of ursolic acid (UA) in rat primary vascular smooth muscle cells (VSMCs) and investigated underlying molecular mechanism of action. Rat primary VSMCs were pretreated with UA (10, 20 or 30μM) or amino guanidine (AG, 50μM) for 12h or with PI3K inhibitor LY294002 for 30min or with Akt inhibitor MK2206 for 24h, then 10% fetal bovine serum was used to induce proliferation. CCK-8 was used to assess cell proliferation. To explore the mechanism, cells were treated with UA (10, 20 or 30μM), LY294002 or MK2206, or transient transfected to inhibit miRNA-21 (miRNA-21) or to overexpress PTEN, then quantitative real-time PCR was used to assess the mRNA levels of miRNA-21 and phosphatase and tensin homolog (PTEN) for cells treated with UA or miRNA-21 inhibitor; western blotting was used to measure the protein levels of PTEN and PI3K. UA exerted significant anti-proliferation effects in rat primary VSMCs. Furthermore, UA inhibited the expression of miRNA-21 and subsequently enhanced the expression of PTEN. PTEN was found to inhibit the expression of PI3K. In conclusion, UA exerts anti-proliferation effects in rat primary VSMCs, which is associated with the inhibition of miRNA-21 expression and modulation of PTEN/PI3K signaling pathway.

Targeting oncomiRNAs and mimicking tumor suppressor miRNAs: Νew trends in the development of miRNA therapeutic strategies in oncology (Review)

MicroRNA (miRNA or miR) therapeutics in cancer are based on targeting or mimicking miRNAs involved in cancer onset, progression, angiogenesis, epithelial-mesenchymal transition and metastasis. Several studies conclusively have demonstrated that miRNAs are deeply involved in tumor onset and progression, either behaving as tumor-promoting miRNAs (oncomiRNAs and metastamiRNAs) or as tumor suppressor miRNAs. This review focuses on the most promising examples potentially leading to the development of anticancer, miRNA-based therapeutic protocols. The inhibition of miRNA activity can be readily achieved by the use of miRNA inhibitors and oligomers, including RNA, DNA and DNA analogues (miRNA antisense therapy), small molecule inhibitors, miRNA sponges or through miRNA masking. On the contrary, the enhancement of miRNA function (miRNA replacement therapy) can be achieved by the use of modified miRNA mimetics, such as plasmid or lentiviral vectors carrying miRNA sequences. Combination strategies have been recently developed based on the observation that i) the combined administration of different antagomiR molecules induces greater antitumor effects and ii) some anti-miR molecules can sensitize drug-resistant tumor cell lines to therapeutic drugs. In this review, we discuss two additional issues: i) the combination of miRNA replacement therapy with drug administration and ii) the combination of antagomiR and miRNA replacement therapy. One of the solid results emerging from different independent studies is that miRNA replacement therapy can enhance the antitumor effects of the antitumor drugs. The second important conclusion of the reviewed studies is that the combination of anti-miRNA and miRNA replacement strategies may lead to excellent results, in terms of antitumor effects.

MicroRNA-9 suppresses cell migration and invasion through downregulation of TM4SF1 in colorectal cancer

Transmembrane-4-L6 family 1 (TM4SF1) is upregulated in colorectal carcinoma (CRC). However, the mechanism leading to inhibition of the TM4SF1 is not known. In the present study, we investigated the regulation of TM4SF1 and function of microRNAs (miRNAs) in CRC invasion and metastasis. We analyzed 60 colon cancers and paired normal specimens for TM4SF1 and miRNA-9 (miR-9) expression using quantitative real-time PCR. A bioinformatics analysis identified a putative miR-9 binding site within the 3'-UTR of TM4SF1. We also found that TM4SF1 was upregulated in CRC tissues and CRC cell lines. The expression of TM4SF1 was positively correlated with clinical advanced stage and lymph node metastasis. Moreover, a luciferase assay revealed that miR-9 directly targeted 3'-UTR-TM4SF1. Overexpression of miR-9 inhibited expression of TM4SF1 mRNA and protein, wound healing, transwell migration and invasion of SW480 cells, whereas, overexpression of anti-miR-9 and siRNA-TM4SF1 inversely regulated the TM4SF1 mRNA and protein level in HCT116 cells. Furthermore, miR-9 suppressed not only TM4SF1 expression but also MMP-2, MMP-9 and VEGF expression. In clinical specimens, miR-9 was generally down-regulated in CRC and inversely correlated with TM4SF1 expression. These results suggest that miR-9 functions as a tumor-suppressor in CRC, and that its suppressive effects mediate invasion and metastasis by inhibition of TM4SF1 expression. Our results also indicate that miR-9 might be a novel target for the treatment of CRC invasion and metastasis.

MicroRNA-720 promotes in vitro cell migration by targeting Rab35 expression in cervical cancer cells

Background

MicroRNA-720 (miR-720), a nonclassical miRNA, is involved in the initiation and progression of several tumors. In our previous studies, miR-720 was shown to be significantly upregulated in cervical cancer tissues compared with normal cervical tissues. However, the precise biological functions of miR-720, and its molecular mechanisms of action, are still unknown.

Results

Microarray expression profiles, luciferase reporter assays, and western blot assays were used to validate Rab35 as a target gene of miR-720 in HEK293T and HeLa cells. The regulation of Rab35 expression by miR-720 was assessed using qRT-PCR and western blot assays, and the effects of exogenous miR-720 and Rab35 on cell migration were evaluated in vitro using Transwell^® assay, wound healing assay, and real-time analyses in HeLa cells. The influences of exogenous miR-720 on cell proliferation were evaluated in vitro by the MTT assay in HeLa cells. In addition, expression of E-cadherin and vimentin associated with epithelial-mesenchymal transition were also assessed using western blot analyses after transfection of miR-720 mimics and Rab35 expression vectors. The results showed that the small GTPase, Rab35, is a direct functional target of miR-720 in cervical cancer HeLa cells. By targeting Rab35, overexpression of miR-720 resulted in a decrease in E-cadherin expression and an increase in vimentin expression and finally led to promotion of HeLa cell migration. Furthermore, reintroduction of Rab35 3′-UTR(−) markedly reversed the induction of cell migration in miR-720-expressing HeLa cells.

Conclusions

The miR-720 promotes cell migration of HeLa cells by downregulating Rab35. The results show that miR-720 is a novel cell migration-associated gene in cervical cancer cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s13578-015-0047-5) contains supplementary material, which is available to authorized users.