miRNA-320a inhibits tumor proliferation and invasion by targeting c-Myc in human hepatocellular carcinoma

Molecular Mechanisms in Tumorigenesis of Hepatocellular Carcinoma and in Target Treatments-An Overview

Hepatocellular carcinoma is the most common primary malignancy of the liver, with hepatocellular differentiation. It is ranked sixth among the most common cancers worldwide and is the third leading cause of cancer-related deaths. The most important etiological factors discussed here are viral infection (HBV, HCV), exposure to aflatoxin B1, metabolic syndrome, and obesity (as an independent factor). Directly or indirectly, they induce chromosomal aberrations, mutations, and epigenetic changes in specific genes involved in intracellular signaling pathways, responsible for synthesis of growth factors, cell proliferation, differentiation, survival, the metastasis process (including the epithelial-mesenchymal transition and the expression of adhesion molecules), and angiogenesis. All these disrupted molecular mechanisms contribute to hepatocarcinogenesis. Furthermore, equally important is the interaction between tumor cells and the components of the tumor microenvironment: inflammatory cells and macrophages-predominantly with a pro-tumoral role-hepatic stellate cells, tumor-associated fibroblasts, cancer stem cells, extracellular vesicles, and the extracellular matrix. In this paper, we reviewed the molecular biology of hepatocellular carcinoma and the intricate mechanisms involved in hepatocarcinogenesis, and we highlighted how certain signaling pathways can be pharmacologically influenced at various levels with specific molecules. Additionally, we mentioned several examples of recent clinical trials and briefly described the current treatment protocol according to the NCCN guidelines.

MicroRNA copy number alterations in the malignant transformation of pleomorphic adenoma to carcinoma ex pleomorphic adenoma

OBJECTIVE

This study used array comparative genomic hybridization to assess copy number alterations (CNAs) involving miRNA genes in pleomorphic adenoma (PA), recurrent pleomorphic adenoma (RPA), residual PA, and carcinoma ex pleomorphic adenoma (CXPA).

MATERIALS AND METHODS

We analyzed 13 PA, 4 RPA, 29 CXPA, and 14 residual PA using Nexus Copy Number Discovery software. The miRNAs genes affected by CNAs were evaluated based on their expression patterns and subjected to pathway enrichment analysis.

RESULTS

Across the groups, we found 216 CNAs affecting 2261 miRNA genes, with 117 in PA, 59 in RPA, 846 in residual PA, and 2555 in CXPA. The chromosome 8 showed higher involvement in altered miRNAs in PAs and CXPA patients. Six miRNA genes were shared among all groups. Additionally, miR-21, miR-455-3p, miR-140, miR-320a, miR-383, miR-598, and miR-486 were prominent CNAs found and is implicated in carcinogenesis of several malignant tumors. These miRNAs regulate critical signaling pathways such as aerobic glycolysis, fatty acid biosynthesis, and cancer-related pathways.

CONCLUSION

This study was the first to explore CNAs in miRNA-encoding genes in the PA-CXPA sequence. The findings suggest the involvement of numerous miRNA genes in CXPA development and progression by regulating oncogenic signaling pathways.

Methods for assessing the effect of microRNA on stemness genes

According to the latest concepts, for micrometastasis to develop into macrometastasis, differentiated cancer cells must revert to a dedifferentiated state. Activation of stemness genes plays a key role in this transition. Suppression of stemness gene expression using microRNAs can become the basis for the development of effective anti-metastatic drugs. This article provides an overview of the existing methods for assessing the effect of microRNAs on stemness genes and cancer cell dedifferentiation.

Integrative analysis of microRNA-320a-related genes in osteoarthritis cartilage

Objectives

To investigate microRNA-320a-related differentially expressed genes (DEGs) and pathways in osteoarthritis (OA) by bioinformatic analysis.

Methods

The target genes of microRNA-320a were searched and collected from MiRTarBase microRNA Targets dataset, the TargetScan Predicted Nonconserved microRNA Targets dataset and the TargetScan Predicted Conserved microRNA Targets dataset. OA-related microRNAs and OA-related target genes were collected from GeneCards databases. The pathway enrichment analysis of miRNAs ware performed by Funrich analysis tool. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was obtained from Database for Annotation, Visualization and Integrated Discovery (DAVID). GeneMANIA and STRING are used for protein-protein interaction (PPI) network analysis. Module analysis was performed by Cytoscape.

Results

A total of 176 OA related miRNAs were searched and collected for enrichment analysis, and microRNA-320a was one of OA related miRNAs. Enrichment pathway and analysis of 1721 miRNA-320a-related target genes from MiRTarBase and TargetScan were performed using the online tools Metascape. And results shown that the biological processes were remarkably enriched in chromatin organization, cellular response to DNA damage stimuli, mRNA metabolic process, protein ubiquitination, and regulation of cell adhesion. And then we analysed miRNA-320a-targeted OA genes via KEGG, GO enrichment and PPI Network. Our results showed that miRNA-320a played a role in OA through FoxO signaling pathway, PI3K-Akt signaling pathway, focal adhesion, MAPK signaling pathway, HIF-1 signaling pathway and cellular senescence. And we speculate that MAPK signaling pathway plays a key role in the effect of miRNA-320a on OA.

Conclusion

This study implied microRNA-320a-related DEGs and dysregulated pathways in OA. The aim is to screen miRNA-320a-related genes and pathways in OA and, eventually, to improve the understanding of underlying mechanisms of miRNA-320a in OA.

Selection of endogenous control and identification of significant microRNA deregulations in cervical cancer

Introduction

Cervical cancer causes approximately 350,000 deaths each year. The availability of sensitive and specific diagnostic tests to detect cervical cancer in its early stages is essential to improve survival rates.

Methods

In this study, we compared two strategies for selecting endogenous controls: miRNA profiling by small-RNA sequencing and a commercially available microfluidic card with 30 recommended endogenous controls preloaded by the manufacturer. We used the RefFinder algorithm and coefficient of variation to select endogenous controls. We selected the combination of miR-181a-5p and miR-423-3p as the most optimal normalizer. In the second part of this study, we determined the differential expression (between tumor/non-tumor groups) of microRNA in cervical cancer FFPE tissue samples. We determined the comprehensive miRNA expression profile using small-RNA sequencing technology and verified the results by real-time PCR. We determined the relative expression of selected miRNAs using the 2^-ΔΔCt method.

Results

We detected statistically significant upregulation of miR-320a-3p, miR-7704, and downregulation of miR-26a-5p in the tumor group compared to the control group. The combination of these miRNAs may have the potential to be utilized as a diagnostic panel for cervical cancer. Using ROC curve analysis, the proposed panel showed 93.33% specificity and 96.97% sensitivity with AUC = 0.985.

Conclusions

We proposed a combination of miR-181a-5p and miR-423-3p as optimal endogenous control and detected potentially significant miRNAs (miR-320a-3p, miR-7704, miR-26a-5p). After further validation of our results, these miRNAs could be used in a diagnostic panel for cervical cancer.

Potential involvement of circulating extracellular vesicles and particles on exercise effects in malignancies

Physical activity and exercise have been widely related to prevention, treatment, and control for several non-communicable diseases. In this context, there are innumerous pre-clinical and clinical evidence indicating the potential role of exercise, beyond cancer prevention and survival, improved quality of life, including on psychological components, bone health and cachexia, from cancer survivors is described as well. This mini-review raises the potential role of circulating extracellular and particles vesicles (EVPs) cargo, as exerkines, conducting several positive effects on adjacent and/or distant tissues such as tumor, immune, bone and muscle cells. We highlighted new perspectives about microRNAs into EVPs changes induced by exercise and its benefits on malignancies, since microRNAs can be implicated with intricated physiopathological processes. Potential microRNAs into EVPs were pointed out here as players spreading beneficial effects of exercise, such as miR-150-5p, miR-124, miR-486, and miRNA-320a, which have previous findings on involvement with clinical outcomes and as well as tumor microenvironment, regulating intercellular communication and tumor growth. For example, high-intensity interval aerobic exercise program seems to increase miR-150 contents in circulating EVPs obtained from women with normal weight or overweight. In accordance circulating EVPs miR-150-5p content is correlated with prognosis colorectal cancer, and ectopic expression of miR-150 may reduce cell proliferation, invasion and metastasis. Beyond the involvement of bioactive miRNAs into circulating EVPs and their pathways related to clinical and preclinical findings, this mini review intends to support further studies on EVPs cargo and exercise effects in oncology.

Reciprocal interplays between MicroRNAs and pluripotency transcription factors in dictating stemness features in human cancers

The interplay between microRNAs (miRNAs) and pluripotency transcription factors (TFs) orchestrates the acquisition of cancer stem cell (CSC) features during the course of malignant transformation, rendering them essential cancer cell dependencies and therapeutic vulnerabilities. In this review, we discuss emerging themes in tumor heterogeneity, including the clonal evolution and the CSC models and their implications in resistance to cancer therapies, and then provide thorough coverage on the roles played by key TFs in maintaining normal and malignant stem cell pluripotency and plasticity. In addition, we discuss the reciprocal interactions between miRNAs and MYC, OCT4, NANOG, SOX2, and KLF4 pluripotency TFs and their contributions to tumorigenesis. We provide our view on the potential to interfere with key miRNA-TF networks through the use of RNA-based therapeutics as single agents or in combination with other therapeutic strategies, to abrogate the CSC state and render tumor cells more responsive to standard and targeted therapies.

miR-382-5p promotes cell invasion in hepatocellular carcinoma by targeting PTEN to activate PI3K/Akt signaling pathway

Purpose

This study aimed at investigating miR-382-5p expression in tissues and cell lines with hepatocellular carcinoma (HCC), its effects on the invasion of HCC cells, and related mechanisms.

Methods

miR-382-5p expression in HCC tissues, adjacent tissues, cell lines of normal hepatic cells, and HCC cells were detected by qRT-PCR, indicating its upregulation or downregulation in HCC cell lines (Hep3B and HCCLM3). The effect of miR-382-5p on cell invasion was observed by the Transwell experiment. The targeting relationship of miR-382-5p and the phosphatase and tensin homolog (PTEN) was analyzed using bioinformatics tools and the luciferase reporter gene assay. The correlation between miR-382-5p and PTEN was analyzed with Spearman correlation analysis. PTEN expression was observed after upregulation and downregulation of miR-382-5p expression. The effect of miR-382-5p on the expression of key proteins in PI3K/Akt signaling pathway was determined by Western blot.

Results

miR-382-5p expression was upregulated in both HCC tissues and cell lines (both P<0.05). Upregulation or downregulation of miR-382-5p significantly promoted or inhibited the invasion of cell lines, Hep3B, and HCCLM3. The luciferase reporter gene assay confirmed that PTEN is a target of miR-382-5p. The expressions of miR-382-5p and PTEN were negatively correlated (r=−0.742, P<0.001). Upregulation of PTEN expression by plasmid transfection can reverse the invasive effect of miR-382-5p on HCC cells. Upregulation of miR-382-5p can activate PI3K/Akt signaling pathway, and downregulation of miR-382-5p can inhibit PI3K/Akt signaling pathway.

Conclusions

miR-382-5p can activate the PI3K/Akt signaling pathway by targeting PTEN and promote HCC cell invasion.

MiR-138 is a potent regulator of the heterogenous MYC transcript population in cancers

3'UTR shortening in cancer has been shown to activate oncogenes, partly through the loss of microRNA-mediated repression. This suggests that many reported microRNA-oncogene target interactions may not be present in cancer cells. One of the most well-studied oncogenes is the transcription factor MYC, which is overexpressed in more than half of all cancers. MYC overexpression is not always accompanied by underlying genetic aberrations. In this study, we demonstrate that the MYC 3'UTR is shortened in colorectal cancer (CRC). Using unbiased computational and experimental approaches, we identify and validate microRNAs that target the MYC coding region. In particular, we show that miR-138 inhibits MYC expression and suppresses tumor growth of CRC and hepatocellular carcinoma (HCC) cell lines. Critically, the intravenous administration of miR-138 significantly impedes MYC-driven tumor growth in vivo. Taken together, our results highlight the previously uncharacterized shortening of the MYC 3'UTR in cancer, and identify miR-138 as a potent regulator of the heterogenous MYC transcript population.

Nanomedicine in Hepatocellular Carcinoma: A New Frontier in Targeted Cancer Treatment

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death and is associated with a dismal median survival of 2-9 months. The fundamental limitations and ineffectiveness of current HCC treatments have led to the development of a vast range of nanotechnologies with the goal of improving the safety and efficacy of treatment for HCC. Although remarkable success has been achieved in nanomedicine research, there are unique considerations such as molecular heterogeneity and concomitant liver dysfunction that complicate the translation of nanotheranostics in HCC. This review highlights the progress, challenges, and targeting opportunities in HCC nanomedicine based on the growing literature in recent years.

DNA Methylation Profiling of MYC, SMAD2/3 and DNMT3A in Colorectal Cancer

Epigenetic modifications, particularly DNA methylation, is commonplace and a remarkable factor in carcinogenesis transformation. Conspicuously, previous findings have presented a cluster of irregular promoter methylation alterations related with silencing of tumor suppressor genes, little is accepted regarding their sequential DNA methylation (hypo and hyper) modifications during the cancer progression. In this way, fluctuations of DNA methylation of many genes, especially MYC, SMAD2/3, and DNMT3A, have an impressive central key role in many different cancers, including colorectal cancer (CRC). CRC is distinguished by DNA methylation, which is related to tumorigenesis and also genomic instability. Importantly, molecular heterogeneity between multiple adenomas in different patients with CRC may show diverse developmental phenotypes for these kinds of tumors. Conclusively, studying factors that are involved in CRC carcinogenesis, especially the alterations in epigenetic elements, such as DNA methylation besides RNA remodeling, and histone modification, acetylation and phosphorylation, can be influential to find new therapeutic and diagnostic biomarkers in this type of malignancy. In this account, we discuss and address the potential significant methylated modifications of these genes and their importance during the development of CRC carcinogenesis.

Tumor suppressor functions of miRNA-375 in nasopharyngeal carcinoma through inhibition of ubiquitin-specific protease 1 expression

BACKGROUND

Nasopharyngeal carcinoma (NPC) development involves many genetic alterations. This study profiled differentially expressed microRNAs (DE-miRNAs) and selected miR-375 for further study.

METHODS

DE-miRNAs were screened using online databases and subjected to various analyzes. miR-375 mimics with negative control (NC) cDNA, and a ubiquitin-specific protease 1 (USP1) as well as a NC group were transfected into NPC cells for analysis by quantitative PCR, western blotting, wound healing, Transwell, flow cytometry, cell counting kit-8 (CCK-8), and luciferase gene reporter assays.

RESULTS

Among these DE-miRNAs, miR-375 was downregulated and miR-21 was upregulated in NPC cells. Bioinformatical analysis identified USP1 as a potential target gene of miR-375. Increased USP1 expression was associated with poor survival of head and neck cancer patients. The luciferase assay confirmed miR-375 binding to the USP1 3'-untranslated region (UTR), while the transfection experiment confirmed miR-375 expression reduced USP1 expression. USP1 overexpression reversed the anti-tumor activity of miR-375 in NPC cells as determined by tumor cell migration, invasion, apoptosis, and viability assays. In addition, USP1 overexpression activated phosphoinositide 3-kinase (PI3K) signaling, whereas a selective PI3K inhibitor (S2739) could reverse the effects of USP1 on NPC cells in vitro.

CONCLUSIONS

miR-375 and miR-21 are both related to NPC and miR-375 can target USP1. Further experiments revealed that up-regulated miR-375 expression led to USP1 down-regulation, and miR-375 overexpression suppressed PI3K/Akt signaling and inhibited NPC cell migration and invasion, but promoted NPC cell apoptosis.

The Role of Non-Coding RNAs in the Regulation of the Proto-Oncogene MYC in Different Types of Cancer

Alterations in the expression level of the MYC gene are often found in the cells of various malignant tumors. Overexpressed MYC has been shown to stimulate the main processes of oncogenesis: uncontrolled growth, unlimited cell divisions, avoidance of apoptosis and immune response, changes in cellular metabolism, genomic instability, metastasis, and angiogenesis. Thus, controlling the expression of MYC is considered as an approach for targeted cancer treatment. Since c-Myc is also a crucial regulator of many cellular processes in healthy cells, it is necessary to find ways for selective regulation of MYC expression in tumor cells. Many recent studies have demonstrated that non-coding RNAs play an important role in the regulation of the transcription and translation of this gene and some RNAs directly interact with the c-Myc protein, affecting its stability. In this review, we summarize current data on the regulation of MYC by various non-coding RNAs that can potentially be targeted in specific tumor types.

MicroRNA-320a-containing exosomes from human umbilical cord mesenchymal stem cells curtail proliferation and metastasis in lung cancer by binding to SOX4

Exosomes from human umbilical cord mesenchymal stem cells (HUCMSCs) containing microRNAs (miRNAs) have been underscored as possible therapeutic options for cancers. Hence, our goal here was to investigate the relevance of miR-320a-containing exosomes from HUCMSCs to lung cancer. First, H1299 and H460 cells were co-cultured with the exosomes overexpressing miR-320a from HUCMSCs. The data displayed that HUCMSCs-secreted exosomes expressing miR-320a exerted anti-tumor effects in vitro and in vivo. Online analysis available at TargetScan database revealed that miR-320a bound to sex-determining region Y-box 4 (SOX4), and the luciferase reporter gene assay clarified this targeting relationship. Next, a β-catenin-specific agonist WAY-262611 was delivered into the H1299 and H460 cells to assess the effects of the Wnt/β-catenin pathway on lung cancer cellular processes. The results demonstrated that WAY-262611 potentiated lung cancer cell viability, invasion, and migration, but inhibited cell apoptosis. Altogether, exosomes carrying miR-320a from HUCMSCs might suppress lung cancer cell growth via the SOX4/Wnt/β-catenin axis, which highpoints the potency of exosomes expressing miR-320a as a possible therapeutic option for lung cancer treatment.

Targeting Signaling Pathway Networks in Several Malignant Tumors: Progresses and Challenges

Malignant tumors remain the health problem of highest concern among people worldwide due to its high mortality and recurrence. Lung, gastric, liver, colon, and breast cancers are among the top five malignant tumors in terms of morbidity and mortality. In cancer biology, aberrant signaling pathway regulation is a prevalent theme that drives the generation, metastasis, invasion, and other processes of all malignant tumors. The Wnt/β-catenin, PI3K/AKT/mTOR, Notch and NF-kB pathways are widely concerned and signal crosstalks exist in the five solid tumors. This review provides an innovative summary of the recent progress in research on these signaling pathways, the underlying mechanism of the molecules involved in these pathways, and the important role of some miRNAs in tumor-related signaling pathways. It also presents a brief review of the antitumor molecular drugs that target these signaling pathways. This review may provide a theoretical basis for the study of the molecular biological mechanism of malignant tumors and vital information for the development of new treatment strategies with a focus on efficacy and the reduction of side effects.

MicroRNA 320, an Anti-Oncogene Target miRNA for Cancer Therapy

MicroRNAs are a set of highly conserved non-coding RNAs that control gene expression at the post-transcriptional/translational levels by binding to the 3′-UTR of diverse target genes. Increasing evidence indicates that miRNAs not only play a vital role in many biological processes, but they are also frequently deregulated in pathological conditions, including cancer. The miR-320 family is one of many tumor suppressor families and is composed of five members, which has been demonstrated to be related to the repression of epithelial-mesenchymal transition (EMT) inhibition, cell proliferation, and apoptosis. Moreover, this family has been shown to regulate drug resistance, and act as a potential biomarker for the diagnosis, prognosis, and prediction of cancer. In this review, we summarized recent research with reference to the tumor suppressor function of miR-320 and the regulation mechanisms of miR-320 expression. The collected evidence shown here supports that miR-320 may act as a novel biomarker for cancer prognosis and therapeutic response to cancer treatment.

Circulating miR-320a Acts as a Tumor Suppressor and Prognostic Factor in Non-small Cell Lung Cancer

Dysregulated expression profiles of microRNAs (miRNAs) have been observed in several types of cancer, including non-small cell lung cancer (NSCLC); however, the diagnostic and prognostic potential of circulating miRNAs in NSCLC remains largely undefined. Here we found that circulating miR-320a was significantly down-regulated (~5.87-fold; p < 0.0001) in NSCLC patients (n = 80) compared to matched control plasma samples from healthy subjects (n = 80). Kaplan-Meier survival analysis revealed that NSCLC patients with lower levels of circulating miR-320a had overall poorer prognosis and survival rates compared to patients with higher levels (p < 0.0001). Moreover, the diagnostic and prognostic potential of miR-320a correlated with clinicopathological characteristics such as tumor size, tumor node metastasis (TNM) stage, and lymph node metastasis. Functionally, depletion of miR-320a in human A549 lung adenocarcinoma cells induced their metastatic potential and reduced apoptosis, which was reversed by exogenous re-expression of miR-320a mimics, indicating that miR-320a has a tumor-suppressive role in NSCLC. These results were further supported by high levels of epithelial-mesenchymal transition (EMT) marker proteins (e.g., Beta-catenin, MMP9, and E-cadherin) in lung cancer cells and tissues via immunoblot and immunohistochemistry experiments. Moreover, through bioinformatics and dual-luciferase reporter assays, we demonstrated that AKT3 was a direct target of miR-320a. In addition, AKT3-associated PI3K/AKT/mTOR protein-signaling pathways were elevated with down-regulated miR-320a levels in NSCLC. These composite data indicate that circulating miR-320a may function as a tumor-suppressor miRNA with potential as a prognostic marker for NSCLC patients.

Decreased serum exosomal miR-320a expression is an unfavorable prognostic factor in patients with hepatocellular carcinoma

Objective

Circulating microRNAs (miRNAs) have promising potential as diagnostic or prognostic biomarkers for hepatocellular carcinoma (HCC). This study aimed to analyze the clinical significance of serum exosomal miR-320a expression in patients with HCC.

Methods

A total of 104 patients with HCC, 55 patients with chronic liver disease (CLD), and 50 healthy volunteers were enrolled. Serum exosomal miR-320a levels were measured by quantitative reverse-transcriptase polymerase chain reaction and compared among the groups. The relationships between exosomal miR-320a levels and clinicopathological factors in patients with HCC were also analyzed.

Results

Serum exosomal miR-320a levels were significantly lower in patients with HCC compared with patients with CLD and healthy controls. Receiver-operating characteristic curve analysis showed that serum exosomal miR-320a had good diagnostic value for distinguishing between HCC subjects and normal controls. Serum exosomal miR-320a levels were significantly elevated 1 month after surgery in patients with HCC. Moreover, serum exosomal miR-320a downregulation was strongly associated with positive lymph node metastasis, positive vein invasion, advanced TNM stage, and shorter survival. Serum exosomal miR-320a was confirmed as an independent prognostic marker for HCC.

Conclusions

Collectively, these results indicate that serum exosomal miR-320a might be a potential biomarker for the detection and prognosis of HCC.

C-X-C chemokine receptor 2 (Cxcr2) promotes hepatocellular carcinoma immune evasion via regulating programmed death-ligand 1 (PD-L1)

Strategies to sensitize hepatocellular carcinomas (HCC) to programmed death-1 (PD1)/programmed death-ligand 1 (PD-L1) inhibitor therapies are important in improving the survival of HCC patients. The aim of the study was to characterize C-X-C chemokine receptor 2 (Cxcr2) as a therapeutic target in HCC and evaluate the effects of Cxcr2 suppression in sensitizing HCC to PD1/PD-L1 inhibitor therapies. To this end, we constructed a Cxcr2-knockout HCC cell line (Hepa1-6 KO) using the CRISPR-Cas9 approach and assessed the tumor growth rate and survival of mice after subcutaneously inoculating Hepa1-6 KO cells in mice. We show that Cxcr2 knockdown does not dramatically inhibit tumor growth and improve mouse survival. In tumor xenografts, the proportion of T cells is not affected but the ratio of M1/M2 macrophage is greatly increased. Cxcr2 knockdown does not alter cell viability but macrophages co-cultured with Hepa1-6 KO cells are shifted to M1 phenotypes compared to WT cells. Hepa-1-6 KO cells exhibit lower levels of PD-L1 expression. c-Myc is suppressed in Hepa1-6 KO cells, which contributes to PD-L1 downregulation. Knockdown of Cxcr2 decreases PD-L1 levels and consequently promotes the shift of macrophages to the M1 phenotype, which is mediated by downregulating c-Myc. In summary, Cxcr2 is a potential target for suppressing immune escape in HCC.

Participation of MicroRNAs in the Treatment of Cancer with Phytochemicals

Cancer is a global health concern and one of the main causes of disease-related death. Even with considerable progress in investigations on cancer therapy, effective anti-cancer agents and regimens have thus far been insufficient. There has been compelling evidence that natural phytochemicals and their derivatives have potent anti-cancer activities. Plant-based anti-cancer agents, such as etoposide, irinotecan, paclitaxel, and vincristine, are currently being applied in medical treatments for patients with cancer. Further, the efficacy of plenty of phytochemicals has been evaluated to discover a promising candidate for cancer therapy. For developing more effective cancer therapy, it is required to apprehend the molecular mechanism deployed by natural compounds. MicroRNAs (miRNAs) have been realized to play a pivotal role in regulating cellular signaling pathways, affecting the efficacy of therapeutic agents in cancer. This review presents a feature of phytochemicals with anti-cancer activity, focusing mainly on the relationship between phytochemicals and miRNAs, with insights into the role of miRNAs as the mediators and the regulators of anti-cancer effects of phytochemicals.

Modulating the Crosstalk between the Tumor and Its Microenvironment Using RNA Interference: A Treatment Strategy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy with one of the highest mortality rates among solid cancers. It develops almost exclusively in the background of chronic liver inflammation, which can be caused by viral hepatitis, chronic alcohol consumption or an unhealthy diet. Chronic inflammation deregulates the innate and adaptive immune responses that contribute to the proliferation, survival and migration of tumor cells. The continuous communication between the tumor and its microenvironment components serves as the overriding force of the tumor against the body's defenses. The importance of this crosstalk between the tumor microenvironment and immune cells in the process of hepatocarcinogenesis has been shown, and therapeutic strategies modulating this communication have improved the outcomes of patients with liver cancer. To target this communication, an RNA interference (RNAi)-based approach can be used, an innovative and promising strategy that can disrupt the crosstalk at the transcriptomic level. Moreover, RNAi offers the advantage of specificity in comparison to the treatments currently used for HCC in clinics. In this review, we will provide the recent data pertaining to the modulation of a tumor and its microenvironment by using RNAi and its potential for therapeutic intervention in HCC.

MiR-320a is associated with cisplatin resistance in lung adenocarcinoma and its clinical value in non-small cell lung cancer: A comprehensive analysis based on microarray data

BACKGROUND

Currently, the main treatment for non-small cell lung cancer (NSCLC) is surgery and chemotherapy. Although major progress has been made in targeted treatment and immunotherapy, the survival rates for this disease are still low and associated with resistance to chemotherapy. Previous studies have shown that histone acetylation and microRNAs (miRNAs) might play an important role in chemotherapy resistance. The aim of this study was to identify candidate miRNAs related to cisplatin (DDP) resistance in lung adenocarcinoma.

METHODS

We used 5-aza-2'-deoxycytidine and trichostatin A to reverse the drug resistance of A549/DDP cells in vitro, and miRNA expression profiling was performed by microarrays to identify candidate miRNAs. In addition, we investigated the correlations between miR-320a expression and clinical characteristics through data collected from Gene Expression Omnibus (GEO) microarrays, and The Cancer Genome Atlas (TCGA) to determine the clinical role of miR-320a in lung adenocarcinoma. Furthermore, we investigated the biological function of miR-320a. TargetScanHuman, PicTar2005 and miRanda v5.1. were used to predict the target genes of miR-320a; then, the function of these genes were suggested from the enrichment of GO categories items and KEGG analyses.

RESULTS

Treatment with 5-Aza-dc significantly inhibited cellular proliferation, and increased apoptosis in the A549/DDP cells compared with the untreated cells. TSA did not reverse cisplatin resistance. MiR-320a was up-regulated during reversal of cisplatin resistance. The lung adenocarcinoma groups had a significantly lower level of miR-320a expression than the control groups. For the bioinformatics analyses, we found some target genes involved in cell cycle progression, tumor progression, the MAPK signaling pathway, and the ErbB signaling pathway. The promising target genes were highly enriched in various pathways in cancer.

CONCLUSIONS

The current study confirmed miR-320a was up-regulated during the revering of cisplatin resistance. The results of bioinformatics analyses may present a new method for investigating the pathogenesis of lung adenocarcinoma.

Role of cellular, molecular and tumor microenvironment in hepatocellular carcinoma: Possible targets and future directions in the regorafenib era

Hepatocellular carcinoma (HCC) remains as one of the major causes of cancer-related mortality, despite the recent development of new therapeutic options. Regorafenib, an oral multikinase inhibitor, is the first systemic therapy that has a survival benefit for patients with advanced HCC that have a poor response to sorafenib. Even though regorafenib has been approved by the FDA, the clinical trial for regorafenib treatment does not show significant improvement in overall survival. The impaired efficacy of regorafenib caused by various resistance mechanisms, including epithelial-mesenchymal transitions, inflammation, angiogenesis, hypoxia, oxidative stress, fibrosis and autophagy, still needs to be resolved. In this review, we provide insight on regorafenib microenvironmental, molecular and cellular mechanisms and interactions in HCC treatment. The aim of this review is to help physicians select patients that would obtain the maximal benefits from regorafenib in HCC therapy.

MicroRNA dysregulation interplay with childhood abdominal tumors

Abdominal tumors (AT) in children account for approximately 17% of all pediatric solid tumor cases, and frequently exhibit embryonal histological features that differentiate them from adult cancers. Current molecular approaches have greatly improved the understanding of the distinctive pathology of each tumor type and enabled the characterization of novel tumor biomarkers. As seen in abdominal adult tumors, microRNAs (miRNAs) have been increasingly implicated in either the initiation or progression of childhood cancer. Moreover, besides predicting patient prognosis, they represent valuable diagnostic tools that may also assist the surveillance of tumor behavior and treatment response, as well as the identification of the primary metastatic sites. Thus, the present study was undertaken to compile up-to-date information regarding the role of dysregulated miRNAs in the most common histological variants of AT, including neuroblastoma, nephroblastoma, hepatoblastoma, hepatocarcinoma, and adrenal tumors. Additionally, the clinical implications of dysregulated miRNAs as potential diagnostic tools or indicators of prognosis were evaluated.

RALY may cause an aggressive biological behavior and a dismal prognosis in non-small-cell lung cancer

RALY is a member of the heterogeneous nuclear ribonucleoprotein (hnRNP), an RNA-binding protein that plays a role in mRNA splicing and metabolism, may be involved in tumorigenesis and development. Some studies have shown that RALY plays a role in promoting cancer in a variety of tumors. However, the biological function and molecular mechanism of RALY in non-small cell lung cancer (NSCLC) remain unknown. TCGA databases were used to gather RALY expression data in NSCLC, the results indicate that RALY is highly expressed in cancer tissue of NSCLC patients. Then we demonstrated that RALY gene expression was notably upregulated in NSCLC tissue and cell lines (A549 and SK-MES-1), and was associated with lymph node metastasis (P = 0.007) and poorer overall survival in NSCLC patients. Subsequently, RALY in A549 and SK-MES-1 cells was knocked down by lentivirus to analyze the consequences of RALY on the biological behavior of NSCLC cell lines. Our results indicated that RALY knockdown impaired NSCLC cells proliferation, migration, and invasion, as well as arrested cells in G1 phase, and the reintroduction of RALY recused its biological phenotype. Furthermore, RALY knockdown down-regulated the expression levels of c-Myc, Cyclin D1, CDK4, MMP9, Rho A ,Rho C, N-cadherin and β-catenin, and up-regulated the expression levels of P27, Rho B and E-cadherin. Therefore, targeting RALY could be a promising molecular target for NSCLC treatment.

Long non-coding RNA SUMO1P3 promotes hepatocellular carcinoma progression through activating Wnt/β-catenin signalling pathway by targeting miR-320a

In this study, we aimed to investigate expression profile of long non‐coding RNA (lncRNA) SUMO1P3, and its role and molecular mechanisms in the progression of hepatocellular carcinoma (HCC).

The expression of SUMO1P3 in HCC tissues and cells was detected using quantitative real‐time polymerase chain reaction (qRT‐PCR). The chi‐squared test was used to estimate the relationship between SUMO1P3 levels and clinical characteristics of HCC cases. Cellular biological behaviours were investigated using MTT, transwell assays and wound healing assay. Bioinformatics and dual‐luciferase reporter assays were performed to identify potential target of SUMO1P3 in HCC. Additionally, protein analysis was carried out using Western blot.

The expression of SUMO1P3 was significantly higher in HCC tissues and cells than in non‐cancerous specimens and normal cells (P < .01). Moreover, its up‐regulation was closely correlated with lymph node metastasis (P = .027) and TNM stage (P = .019). SUMO1P3 knockdown inhibited the proliferation, migration and invasion of HCC cells. MiR‐320a was a potential target of SUMO1P3, and its expression was negatively regulated by SUMO1P3 in HCC SUMO1P3 could activate Wnt/β‐catenin pathway, which was mediated by miR‐320a.

Elevated expression of SUMO1P3 predicts malignant progression among HCC patients. SUMO1P3 enhances Wnt/β‐catenin pathway through sponging miR‐320a, thus contributing to aggressive progression of HCC.

Dysregulated MicroRNA Fingerprints and Methylation Patterns in Hepatocellular Carcinoma, Cancer Stem Cells, and Mesenchymal Stem Cells

Hepatocellular carcinoma (HCC) is one of the top causes of cancer mortality worldwide. Although HCC has been researched extensively, there is still a need for novel and effective therapeutic interventions. There is substantial evidence that initiation of carcinogenesis in liver cirrhosis, a leading cause of HCC, is mediated by cancer stem cells (CSCs). CSCs were also shown to be responsible for relapse and chemoresistance in several cancers, including HCC. MicroRNAs (miRNAs) constitute important epigenetic markers that regulate carcinogenesis by acting post-transcriptionally on mRNAs, contributing to the progression of HCC. We have previously shown that co-culture of cancer cells with mesenchymal stem cells (MSCs) could induce the reprogramming of MSCs into CSC-like cells. In this review, we evaluate the available data concerning the epigenetic regulation of miRNAs through methylation and the possible role of this regulation in stem cell and somatic reprogramming in HCC.

miR‑320a upregulation contributes to the development of preeclampsia by inhibiting the growth and invasion of trophoblast cells by targeting interleukin 4

Preeclampsia (PE) is a serious pregnancy‑specific pathologic complication, and represents a primary cause of mother and fetus mortality. Abnormally expressed microRNAs (miRNAs) serve important regulatory roles in the development of PE. At present, the pathogenesis and molecular mechanism of PE remain unclear. The aim of the present study was to investigate the potential functions of miRNA (miR)‑320a in the human extravillous trophoblast cell line HTR‑8/SVneo and to identify the molecular mechanisms underlying miR‑320a function. Reverse transcription‑quantitative PCR was used in the present study to detect the levels of miR‑320a in the placentas of 57 pregnant patients with PE and 57 healthy pregnant patients. The effects of miR‑320a overexpression on the proliferation and invasion of HTR‑8/SVneo cells were determined using MTT and Transwell invasion assays. Western blot analysis and dual luciferase reporter assay were used to identify the genes targeted by miR‑320a. The present results suggested that miR‑320a expression level was decreased in placentas of patients with PE and the expression level of miR‑320a was found to be associated with the pathogenesis of PE (P<0.05). Overexpression of miR‑320a using miR‑320a mimics significantly inhibited cell proliferation and invasion in HTR‑8/SVneo cells in vitro (P<0.05). Furthermore, interleukin (IL)‑4 was identified to be a direct target gene of miR‑320a. miR‑320a could repress IL‑4 expression by binding to its 3' untranslated region (P<0.05). Mechanistic studies suggested that IL‑4 was a functional target gene of miR‑320a, and miR‑320a upregulation inhibited the proliferation and invasion of HTR‑8/SVneo cells by directly targeting IL‑4 (P<0.05). Collectively, to the best of our knowledge, the present study is the first to suggest that miR‑320a may be a downregulated miRNA during PE, and IL‑4 may act as a functional target gene of miR‑320a. The present study suggested that miR‑320a upregulation was involved in the development of PE by inhibiting the proliferation and invasion of trophoblast cells by targeting IL‑4, indicating that the miR‑320a/IL‑4 pathway may represent a novel therapeutic target for PE treatment.

miRNA-125a-5p inhibits hepatocellular carcinoma cell proliferation and induces apoptosis by targeting TP53 regulated inhibitor of apoptosis 1 and Bcl-2-like-2 protein

The present study aimed to investigate the role and underlying molecular mechanism of microRNA (miR)-125a-5p in hepatocellular carcinoma. The level of miR-125a-5p was detected using reverse transcription-quantitative polymerase chain reaction. TargetScan was used to investigate the association between miR-125a-5p and TP53-regulated inhibitor of apoptosis 1 (TRIAP1)/B cell lymphoma-2-like 2 protein (BCL2L2). Dual luciferase reporter assay was used to confirm this prediction. To investigate the role of miR-125a-5p in hepatocellular carcinoma (HCC) cells, miR-125a-5p was overexpressed in the human HCC cell line PLC/PRF/5 using miR-125a-5p mimics. Subsequently, cell proliferation, cell apoptosis and cell migration were studied using MTT assay, flow cytometry analysis and Transwell assay, respectively. Protein expression levels in the present study were measured by western blot analysis. Taken together, the present results suggested that miR-125a-5p was markedly downregulated in HCC cells. TRIAP1 and BCL2L2 were direct targets of miR-125a-5p and were upregulated in PLC/PRF/5 cells. miR-125a-5p upregulation inhibited PLC/PRF/5 cell viability and migration and induced cell apoptosis. In addition, miR-125a-5p overexpression increased the expression of caspase9 and apoptotic protease-activating factor 1. Notably, the present study revealed that all the effects on PLC/PRF/5 cells elicited by miR-125a-5p overexpression were eliminated by TRIAP1/BCL2L2 upregulation. In conclusion, miR-125a-5p was shown to be downregulated in hepatocellular carcinoma and its upregulation inhibited hepatocellular carcinoma cell growth and metastasis by targeting TRIAP1 and BCL2L2.

miR-148a regulates expression of the transferrin receptor 1 in hepatocellular carcinoma

Transferrin receptor 1 (TFR1) is a transmembrane glycoprotein that allows for transferrin-bound iron uptake in mammalian cells. It is overexpressed in various cancers to satisfy the high iron demand of fast proliferating cells. Here we show that in hepatocellular carcinoma (HCC) TFR1 expression is regulated by miR-148a. Within the TFR1 3′UTR we identified and experimentally validated two evolutionarily conserved miRNA response elements (MREs) for miR-148/152 family members, including miR-148a. Interestingly, analyses of RNA sequencing data from patients with liver hepatocellular carcinoma (LIHC) revealed a significant inverse correlation of TFR1 mRNA levels and miR-148a. In addition, TFR1 mRNA levels were significantly increased in the tumor compared to matched normal healthy tissue, while miR-148a levels are decreased. Functional analysis demonstrated post-transcriptional regulation of TFR1 by miR-148a in HCC cells as well as decreased HCC cell proliferation upon either miR-148a overexpression or TFR1 knockdown. We hypothesize that decreased expression of miR-148a in HCC may elevate transferrin-bound iron uptake, increasing cellular iron levels and cell proliferation.

microRNAs: Key players in virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is known as one of the major health problems worldwide. Pathological analysis indicated that a variety of risk factors including genetical (i.e., alteration of tumor suppressors and oncogenes) and environmental factors (i.e., viruses) are involved in beginning and development of HCC. The understanding of these risk factors could guide scientists and clinicians to design effective therapeutic options in HCC treatment. Various viruses such as hepatitis B virus (HBV) and hepatitis C virus (HCV) via targeting several cellular and molecular pathways involved in HCC pathogenesis. Among various cellular and molecular targets, microRNAs (miRNAs) have appeared as key players in HCC progression. miRNAs are short noncoding RNAs which could play important roles as oncogenes or tumor suppressors in several malignancies such as HCC. Deregulation of many miRNAs (i.e., miR-222, miR-25, miR-92a, miR-1, let-7f, and miR-21) could be associated with different stages of HCC. Besides miRNAs, exosomes are other particles which are involved in HCC pathogenesis via targeting different cargos, such as DNAs, RNAs, miRNAs, and proteins. In this review, we summarize the current knowledge of the role of miRNAs and exosomes as important players in HCC pathogenesis. Moreover, we highlighted HCV- and HBV-related miRNAs which led to HCC progression.

Oncogenic and Tumor-Suppressive Roles of MicroRNAs with Special Reference to Apoptosis: Molecular Mechanisms and Therapeutic Potential

MicroRNAs (miRNAs) are the non-coding class of minute RNA molecules that negatively control post-transcriptional regulation of various functional genes. These miRNAs are transcribed from the loci present in the introns of functional or protein-coding genes, exons of non-coding genes, or even in the 3'-untranslated region (3'-UTR). They have potential to modulate the stability or translational efficiency of a variety of target RNA [messenger RNA (mRNA)]. The regulatory function of miRNAs has been elucidated in several pathological conditions, including neurological (Alzheimer's disease and Parkinson's disease) and cardiovascular conditions, along with cancer. Importantly, miRNA identification in cancer progression and invasion has evolved as an incipient era in cancer treatment. Several studies have shown the influence of miRNAs on various cancer processes, including apoptosis, invasion, metastasis and angiogenesis. In particular, apoptosis induction in tumor cells through miRNA has been extensively studied. The biphasic mode (up- and down-regulation) of miRNA expression in apoptosis and other cancer processes has already been determined. The findings of these studies could be utilized to develop potential therapeutic strategies for the management of various cancers. The present review critically describes the oncogenic and tumor suppressor role of miRNAs in apoptosis and other cancer processes, therapy resistance, and use of their presence in the body fluids as biomarkers.

MicroRNA-18a promotes hepatocellular carcinoma proliferation, migration, and invasion by targeting Bcl2L10

BACKGROUND

Hepatocellular carcinoma (HCC) is known to feature several microRNA dysregulations. This study aimed to determine and investigate the prognostic value of microRNA (miRNA/miR)-18a and its role in regulating the progression of HCC.

METHODS

miR-18a expressions in human HCC tissues, pair-matched adjacent normal liver tissues as well as in HCC cell lines were determined by quantitative real-time PCR. The prognostic value of miR-18a was determined using Kaplan-Meier survival analysis and multivariable Cox regression assay. The ability of miR-18a in promoting HCC progression was verified in vitro.

RESULTS

miR-18a expressions in HCC tissues and cells were more than twice those of the normal control group (P<0.05). miR-18a expression was associated with the alpha-fetoprotein (AFP) level, TNM stage, tumor size, and intrahepatic vascular invasion (P<0.05). Kaplan- Meier survival analysis revealed that HCC patients with high expression of miR-18a possessed a more unfavorable prognosis (log-rank P<0.001). Overexpression of miR-18a promoted cell apoptosis and proliferation, induced S phase transition, as well as enhanced the migration and invasion ability of HCC cells. miR-18a was found to directly target the downstream molecule Bcl2L10. Furthermore, overexpressing Bcl2L10 was able to partly reverse the promoting effects of miR-18a on HCC cell progression.

CONCLUSION

miR-18a may serve as a prognostic biomarker of HCC as it is demonstrated to carry out a decisive role in HCC progression by promoting HCC cell invasion, migration, and proliferation through targeting Bcl2L10.

In vivo and in vitro effects of microRNA-221 on hepatocellular carcinoma development and progression through the JAK-STAT3 signaling pathway by targeting SOCS3

Hepatocellular carcinoma (HCC), as the third leading cancer-caused deaths, prevails with high mortality, and affects more than half a million individuals per year worldwide. A former study revealed that microRNA-221 (miR-221) was involved in cell proliferation of liver cancer and HCC development. The current study aims to evaluate whether miR-221 targeting SOCS3 affects HCC through JAK-STAT3 signaling pathway. A series of miR-221 mimic, miR-221 inhibitor, siRNA against SOCS3, and SOCS3 plasmids were introduced to SMMC7721 cells with the highest miR-221 expression assessed. The expression of JAK-STAT3 signaling pathway-related genes and proteins was determined by Western blot analysis. Cell apoptosis, viability, migration, and invasion were evaluated by means of flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide, and transwell assays, respectively. HCC xenograft in nude mice was performed to measure HCC tumor growth. miR-221 was found to be highly expressed but SOCS3 was poorly expressed in HCC tissues. miR-221 expression was correlated with lymph node metastasis (LNM) and tumor node metastasis (TNM) of HCC, and SOCS3 expression was correlated with LNM, differentiation and TNM of HCC. SOCS3 is a target gene of miR-221. MiR-221 mimic or si-SOCS3 exposure was found to induce cell viability, migration, and invasion, and reduce apoptosis. MiR-221 inhibitor was observed to have inhibitory effects on HCC cell proliferation, migration, and invasion. Moreover, the expression of JAK-STAT3 signaling pathway was suppressed by miR-221 inhibitor. Downregulated miR-221 expression could promote its target gene SOCS3 to inhibit the proliferation, invasion and migration of HCC cells by repressing JAK-STAT3 signaling pathway.

MicroRNA‑93‑5p promotes the progression of human retinoblastoma by regulating the PTEN/PI3K/AKT signaling pathway

Numerous reports have indicated that microRNA‑93‑5p (miR‑93‑5p) is involved in the development and progression of human cancer, including non‑small cell lung, gastric and breast cancer; however, the role of miR‑93‑5p in retinoblastoma (RB) remains unknown. In the present study, it was reported that miR‑93‑5p expression levels were significantly upregulated in RB tissues compared with in normal tissues by reverse transcription‑quantitative polymerase chain reaction. Furthermore, it was demonstrated via cell counting kit‑8 and Transwell assays that knockdown of miR‑93‑5p significantly suppressed the proliferation, migration and invasion of RB cells, but promoted cellular apoptosis. Regarding the underlying mechanism, the present study reported that phosphatase and tensin homolog (PTEN) was a direct target of miR‑93‑5p in RB cells. Overexpression of miR‑93‑5p significantly inhibited the expression of PTEN; opposing results were observed when PTEN expression was downregulated. Furthermore, the present study revealed that PTEN expression levels were downregulated and were inversely correlated with that of miR‑93‑5p in RB tissues. Additionally, the present study demonstrated that knockdown of PTEN in miR‑93‑5p‑depleted RB cells significantly reversed the effects of miR‑93‑5p on cell proliferation, migration and invasion; miR‑93‑5p knockdown was suggested to promote PTEN expression, consequently inhibiting the activation of phosphoinositide 3‑kinase (PI3K)/protein kinase B (AKT) signaling pathway. Collectively, the results of the present study demonstrated that miR‑93‑5p may serve a role as an oncogene by modulating the PTEN/PI3K/AKT signaling pathway in RB, indicating that miR‑93‑5p may be a potential therapeutic target for the treatment of RB.

The Role of MicroRNAs in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers, leading to the second cancer-related death in the global. Although the treatment of HCC has greatly improved over the past few decades, the survival rate of patients is still quite low. Thus, it is urgent to explore new therapies, especially seek for more accurate biomarkers for early diagnosis, treatment and prognosis in HCC. MicroRNAs (miRNAs), small noncoding RNAs, are pivotal participants and regulators in the development and progression of HCC. Great progress has been made in the studies of miRNAs in HCC. The key regulatory mechanisms of miRNAs include proliferation, apoptosis, invasion, metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, drug resistance and autophagy in HCC. And exosomal miRNAs also play important roles in proliferation, invasion, metastasis, and drug resistance in HCC by regulating gene expression in the target cells. In addition, some miRNAs, including exosomal miRNAs, can be as potential diagnostic and prediction markers in HCC. This review summarizes the latest researches development of miRNAs in HCC in recent years.

Prognostic Role of MicroRNA-497 In Cancer Patients: A Meta-analysis

Background: MicroRNA-497(miR-497) has been studied for its irreplaceable role of predicting the prognosis of various cancers, but there has been no systematic study to summarize the data. Consequently, we performed this meta-analysis to reveal the association between the expression level of miR-497 and cancer prognosis systematically.

Materials and Methods: PubMed was searched for appropriate studies and a total of 12 eligible publications with 989 cancer patients were recruited into our analysis to assess the strength of the association. Hazard ratios (HRs) and odds ratios (ORs) were analyzed to finish this work.

Results: The cancer patients who have high expressing level of miR-497 are less possible to have lymph node metastasis (OR = 0.25, 95% CI: 0.16-0.40, P < 0.001) and more likely to have favourable tumor-node-metastasis stage (OR = 0.29, 95% CI: 0.17-0.49, P < 0.001). Also, high miR-497 expression level was notably connected to better overall survival (pooled HR = 0.41, 95% CI: 0.32-0.53, P < 0.001).

Conclusions: High expressing levels of miR-497 might be a potential biomarker which can be used to predict the better prognosis of different cancer types.

Transcriptional activation of miR-320a by ATF2, ELK1 and YY1 induces cancer cell apoptosis under ionizing radiation conditions

MicroRNAs (miRNAs or miRs) play important roles in numerous cellular processes, including development, proliferation, tumorigenesis and apoptosis. It has been reported that miRNA expression is induced by ionizing radiation (IR) in cancer cells. However, the underlying molecular mechanisms are not yet fully understood. In this study, endogenous miR‑320a and its primary precursor (pri‑miR‑320a) were assayed by reverse transcription‑quantitative PCR (RT‑qPCR). Luciferase activities were measured using a dual‑luciferase reporter assay system. Western blot analysis was used to determine the protein expressions of upstream and downstream genes of miR‑320a. Cell apoptosis was evaluated by Annexin V apoptosis assay and cell proliferation was measured using the trypan blue exclusion method. The results revealed that miR‑320a expression increased linearly with the IR dose and treatment duration. Three transcription factors, activating transcription factor 2 (ATF2), ETS transcription factor (ELK1) and YY1 transcription factor (YY1), were activated by p38 mitogen‑activated protein kinase (MAPK) and mitogen‑activated protein kinase 8 (JNK) and by upregulated miR‑320a expression under IR conditions. In addition, it was identified that X‑linked inhibitor of apoptosis (XIAP) was an miR‑320a target gene during the IR response. By targeting XIAP, miR‑320a induced apoptosis and inhibited the proliferation of the cancer cells. On the whole, the results of this study demonstrated that miRNA‑320a, regulated by the p38 MAPK/JNK pathway, enhanced the radiosensitivity of cancer cells by inhibiting XIAP and this may thus prove to be a potential therapeutic approach with which to overcome radioresistance in cancer treatment.

Role of microRNAs in the main molecular pathways of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignant neoplasia. HCC is characterized by a poor prognosis. The need to find new molecular markers for its diagnosis and prognosis has led to a progressive increase in the number of scientific studies on this topic. MicroRNAs (miRNAs) are small non-coding RNA that play a role in almost all main cellular pathways. miRNAs are involved in the regulation of expression of the major tumor-related genes in carcinogenesis, acting as oncogenes or tumor suppressor genes. The aim of this review was to identify papers published in 2017 investigating the role of miRNAs in HCC tumorigenesis. miRNAs were classified according to their role in the main molecular pathways involved in HCC tumorigenesis: (1) mTOR; (2) Wnt; (3) JAK/STAT; (4) apoptosis; and (5) MAPK. The role of miRNAs in prognosis/response prediction was taken into consideration. Bearing in mind that the analysis of miRNAs in serum and other body fluids would be crucial for clinical management, the role of circulating miRNAs in HCC patients was also investigated. The most represented miRNA-regulated pathway in HCC is mTOR, but apoptosis, Wnt, JAK/STAT or MAPK pathways are also influenced by miRNA expression levels. These miRNAs could thus be used in clinical practice as diagnostic, prognostic or therapeutic targets for HCC treatment.

Identification of Biological Targets of Therapeutic Intervention for Hepatocellular Carcinoma by Integrated Bioinformatical Analysis

BACKGROUND We screened the potential molecular targets and investigated the molecular mechanisms of hepatocellular carcinoma (HCC). MATERIAL AND METHODS Microarray data of GSE47786, including the 40 μM berberine-treated HepG2 human hepatoma cell line and 0.08% DMSO-treated as control cells samples, was downloaded from the GEO database. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed; the protein-protein interaction (PPI) networks were constructed using STRING database and Cytoscape; the genetic alteration, neighboring genes networks, and survival analysis of hub genes were explored by cBio portal; and the expression of mRNA level of hub genes was obtained from the Oncomine databases. RESULTS A total of 56 upregulated and 8 downregulated DEGs were identified. The GO analysis results were significantly enriched in cell-cycle arrest, regulation of transcription, DNA-dependent, protein amino acid phosphorylation, cell cycle, and apoptosis. The KEGG pathway analysis showed that DEGs were enriched in MAPK signaling pathway, ErbB signaling pathway, and p53 signaling pathway. JUN, EGR1, MYC, and CDKN1A were identified as hub genes in PPI networks. The genetic alteration of hub genes was mainly concentrated in amplification. TP53, NDRG1, and MAPK15 were found in neighboring genes networks. Altered genes had worse overall survival and disease-free survival than unaltered genes. The expressions of EGR1, MYC, and CDKN1A were significantly increased, but expression of JUN was not, in the Roessler Liver datasets. CONCLUSIONS We found that JUN, EGR1, MYC, and CDKN1A might be used as diagnostic and therapeutic molecular biomarkers and broaden our understanding of the molecular mechanisms of HCC.

Upregulation of miR-614 promotes proliferation and inhibits apoptosis in ovarian cancer by suppressing PPP2R2A expression

It has previously been demonstrated that microRNAs (miRNAs) have essential roles and participate in various biological processes by regulating their specific target genes. However, the precise role of miRNAs in ovarian cancer (OC) has not yet been elucidated. The present study demonstrated that miR‑614 expression levels were significantly upregulated in OC tissues and cell lines, whereas decreased miR‑614 demonstrated opposite effects. Furthermore, gain‑of‑function and loss‑of‑function experiments indicated that miR‑614 overexpression promoted cell proliferation and suppressed cell apoptosis. Protein phosphatase 2 regulatory subunit B α, (PPP2R2A) was identified as a direct target of miR‑614 using western blotting and luciferase reporter assays. Notably, silencing of PPP2R2A counter‑acted the effect of miR‑614 inhibitor in OC cell proliferation and cell apoptosis. Overall, the data suggested that miR‑614 promoted cell proliferation and inhibited cell apoptosis of OC cells by targeting PPP2R2A, and may therefore act as a potential target for OC therapy in the future.

Identification of key genes and pathways in meningioma by bioinformatics analysis

Meningioma is the most frequently occurring type of brain tumor. The present study aimed to conduct a comprehensive bioinformatics analysis of key genes and relevant pathways involved in meningioma, and acquire further insight into the underlying molecular mechanisms. Initially, differentially expressed genes (DEGs) in 47 meningioma samples as compared with 4 normal meninges were identified. Subsequently, these DEGs were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. In addition, a protein-protein interaction (PPI) network of the identified DEGs was constructed using the Search Tool for the Retrieval of Interacting Genes and visualized using Cytoscape. In total, 1,683 DEGs were identified, including 66 upregulated and 1,617 downregulated genes. The GO analysis results revealed that the DEGs were significantly associated with the ‘protein binding’, ‘cytoplasm’, ‘extracellular matrix (ECM) organization’ and ‘cell adhesion’ terms. The KEGG analysis results demonstrated the significant pathways included ‘AGE-RAGE signaling pathway in diabetic complications’, ‘PI3K-Akt signaling pathway’, ‘ECM-receptor interaction’ and ‘cell adhesion molecules’. The top five hub genes obtained from the PPI network were JUN, PIK3R1, FOS, AGT and MYC, and the most enriched KEGG pathways associated with the four obtained modules were ‘chemokine signaling pathway’, ‘cytokine-cytokine receptor interaction’, ‘allograft rejection’, and ‘complement and coagulation cascades’. In conclusion, bioinformatics analysis identified a number of potential biomarkers and relevant pathways that may represent key mechanisms involved in the development and progression of meningioma. However, these findings require verification in future experimental studies.

The long non-coding RNA SUMO1P3 facilitates breast cancer progression by negatively regulating miR-320a

Although the long non-coding RNA (lncRNA) SUMO1P3, small ubiquitin-like modifier 1 pseudogene 3, has been shown to play a role in human cancer, the biological function and mechanism of SUMO1P3 in breast cancer remained unclear. In this study, we showed that SUMO1P3 expression was higher in breast cancer tissues when compared to adjacent normal tissues and we found that high levels of SUMO1P3 expression associated significantly with tumor progression and poor survival of breast cancer patients. Moreover, we found that knockdown of SUMO1P3 suppressed proliferation, migration, and invasion of breast cancer cells. Bioinformatics analysis and luciferase reporter assays confirmed that SUMO1P3 binds to miR-320a, which has been identified as a tumor suppressor in various cancers, including breast cancer. We also confirmed that the tumor-promoting effects of SUMO1P3 in breast cancer are partly mediated by negative regulation of miR-320a. Our data indicates that SUMO1P3 functions as an oncogenic lncRNA in breast cancer and may serve as a novel diagnostic and biological target for breast cancer diagnosis and treatment.

Small non-coding RNA profiling in human biofluids and surrogate tissues from healthy individuals: description of the diverse and most represented species

The role of non-coding RNAs in different biological processes and diseases is continuously expanding. Next-generation sequencing together with the parallel improvement of bioinformatics analyses allows the accurate detection and quantification of an increasing number of RNA species. With the aim of exploring new potential biomarkers for disease classification, a clear overview of the expression levels of common/unique small RNA species among different biospecimens is necessary. However, except for miRNAs in plasma, there are no substantial indications about the pattern of expression of various small RNAs in multiple specimens among healthy humans. By analysing small RNA-sequencing data from 243 samples, we have identified and compared the most abundantly and uniformly expressed miRNAs and non-miRNA species of comparable size with the library preparation in four different specimens (plasma exosomes, stool, urine, and cervical scrapes). Eleven miRNAs were commonly detected among all different specimens while 231 miRNAs were globally unique across them. Classification analysis using these miRNAs provided an accuracy of 99.6% to recognize the sample types. piRNAs and tRNAs were the most represented non-miRNA small RNAs detected in all specimen types that were analysed, particularly in urine samples. With the present data, the most uniformly expressed small RNAs in each sample type were also identified. A signature of small RNAs for each specimen could represent a reference gene set in validation studies by RT-qPCR. Overall, the data reported hereby provide an insight of the constitution of the human miRNome and of other small non-coding RNAs in various specimens of healthy individuals.

Dynamic and Modularized MicroRNA Regulation and Its Implication in Human Cancers

MicroRNA is responsible for the fine-tuning of fundamental cellular activities and human disease development. The altered availability of microRNAs, target mRNAs, and other types of endogenous RNAs competing for microRNA interactions reflects the dynamic and conditional property of microRNA-mediated gene regulation that remains under-investigated. Here we propose a new integrative method to study this dynamic process by considering both competing and cooperative mechanisms and identifying functional modules where different microRNAs co-regulate the same functional process. Specifically, a new pipeline was built based on a meta-Lasso regression model and the proof-of-concept study was performed using a large-scale genomic dataset from ~4,200 patients with 9 cancer types. In the analysis, 10,726 microRNA-mRNA interactions were identified to be associated with a specific stage and/or type of cancer, which demonstrated the dynamic and conditional miRNA regulation during cancer progression. On the other hands, we detected 4,134 regulatory modules that exhibit high fidelity of microRNA function through selective microRNA-mRNA binding and modulation. For example, miR-18a-3p, -320a, -193b-3p, and -92b-3p co-regulate the glycolysis/gluconeogenesis and focal adhesion in cancers of kidney, liver, lung, and uterus. Furthermore, several new insights into dynamic microRNA regulation in cancers have been discovered in this study.

Circulating microRNA-34 family low expression correlates with poor prognosis in patients with non-small cell lung cancer

Background

To evaluate the association of plasma miR-34a/b/c expressions with the clinicopathological properties and the prognosis in non-small cell lung cancer (NSCLC) patients.

Methods

A total of 196 NSCLC patients were recruited in the study. Plasma sample and tumor tissue sample were collected. Total RNA was extracted from plasma and tissue samples, and microR-34a/b/c expression was evaluated by real-time polymerase chain reaction (PCR).

Results

MiR-34a and miR-34c in plasma were positively associated with that in tumor tissue (P<0.001 and P=0.001, respectively). Plasma miR-34a expression was negatively correlated with lymph node metastasis (P=0.002), also tissue miR-34a expression was negatively associated with lymph node metastasis (P=0.018). Furthermore, plasma miR-34a high expression was correlated with prolonged disease-free survival (DFS) (P=0.011) and overall survival (OS) (P=0.011) compared to low expression, and plasma miR-34c high expression could predict longer DFS (P=0.038) than low expression, while no correlation of plasma miR-34b with DFS and OS was discovered. In terms of tissue sample, worse DFS was associated with miR-34a (P=0.002) and miR-34c (P=0.032) low expressions compared with high expressions, and miR-34a (P<0.001), as well as miR-34c (P=0.003) high expressions were associated with longer OS than low expressions. Plasma miR-34a was correlated with prolonged DFS and OS in univariate Cox model, while it could not independently predict DFS and OS of NSCLC patients in multivariate Cox model.

Conclusions

In conclusion, circulating miR-34a and miR-34c might be served as novel prognostic biomarkers in NSCLC patients.

Downregulation of miR-503 Promotes ESCC Cell Proliferation, Migration, and Invasion by Targeting Cyclin D1

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive cancers in China, but the underlying molecular mechanism of ESCC is still unclear. Involvement of microRNAs has been demonstrated in cancer initiation and progression. Despite the reported function of miR-503 in several human cancers, its detailed anti-oncogenic role and clinical significance in ESCC remain undefined. In this study, we examined miR-503 expression by qPCR and found the downregulation of miR-503 expression in ESCC tissue relative to adjacent normal tissues. Further investigation in the effect of miR-503 on ESCC cell proliferation, migration, and invasion showed that enhanced expression of miR-503 inhibited ESCC aggressive phenotype and overexpression of CCND1 reversed the effect of miR-503-mediated ESCC cell aggressive phenotype. Our study further identified CCND1 as the target gene of miR-503. Thus, miR-503 functions as a tumor suppressor and has an important role in ESCC by targeting CCND1.