MicroRNA-424 is down-regulated in hepatocellular carcinoma and suppresses cell migration and invasion through c-Myb

MiR-424 Acts as a Novel Biomarker in the Diagnosis of Patients with Hepatocellular Carcinoma

Objective: MicroRNA-424 (MiR-424) is proved to be a tumor suppressor against many malignancies, including hepatocellular carcinoma (HCC). Nevertheless, its role in diagnosing HCC remained poorly understood. The authors' research investigated diagnostic value of serum miR-424 in HCC. Materials and Methods: Relative expression levels of serum miR-424 in HCC patients and healthy individuals were measured via quantitative real-time polymerase chain reaction. χ2 test was applied to analyze the correlation between miR-424 expression and clinical features of HCC cases. Diagnostic value was estimated via plotting a receiver operating characteristic (ROC) curve. Results: Serum miR-424 expression was obviously downregulated in HCC cases in comparison to healthy persons (p < 0.001). miR-424 expression presented strong correlation with tumor node metastasis stage (p = 0.022), Barcelona Clinic Liver Cancer stage (p < 0.001), metastasis (p = 0.037), and vein invasion (p = 0.033). ROC curve analysis manifested an area under the curve of 0.768 with a sensitivity of 75.0% and a specificity of 72.4%, suggesting that serum miR-424 had high diagnostic value in HCC patients. Conclusions: The data suggest that serum miR-424 may represent a biomarker in early detection of HCC.

A novel circular RNA circRBMS3 regulates proliferation and metastasis of osteosarcoma by targeting miR-424-eIF4B/YRDC axis

Circular RNAs (circRNAs) have been demonstrated to have critical regulatory roles in tumorigenesis. However, the contribution of circRNAs to OS (osteosarcoma) remains largely unknown. circRNA deep sequencing was performed to the expression of circRNAs between OS and chondroma tissues. The regulatory and functional role of circRBMS3 (a circRNA derived from exons 7 to 10 of the RBMS3 gene, hsa_circ_0064644) upregulation was examined in OS and was validated in vitro and in vivo, upstream regulator and downstream target of circRBMS3 were both explored. RNA pull down, a luciferase reporter assay, biotin-coupled microRNA capture and fluorescence in situ hybridization were used to evaluate the interaction between circRBMS3 and micro (mi)-R-424-5p. For in vivo tumorigenesis experiments, Subcutaneous and Orthotopic xenograft OS mouse models were built. Expression of circRBMS3 was higher in OS tissues due to the regulation of adenosine deaminase 1-acting on RNA (ADAR1), an abundant RNA editing enzyme. Our in vitro data indicated that ShcircRBMS3 inhibits the proliferation and migration of osteosarcoma cells. Mechanistically, we showed that circRBMS3 could regulate eIF4B and YRDC, through 'sponging' miR-424-5p. Furthermore, knockdown of circRBMS3 inhibited malignant phenotypes and bone destruction of OS in vivo. Our results reveal an important role for a novel circRBMS3 in the growth and metastasis of malignant tumor cells and offer a fresh perspective on circRNAs in OS progression.

Circ_0006404 enhances hepatocellular carcinoma progression by regulating miR-624

Growing studies have demonstrated that circRNAs (circular RNAs) act potential roles in tumor metastasis and progression. However, the expression and function of circ_0006404 in hepatocellular carcinoma (HCC) remain to be investigated. The expression of circ_0006404 and miR-624 was detected by qRT-PCR. CCK-8 assay, flow cytometry, and wound healing were performed to determine cell proliferation, cycle, and migration. The target of circ_0006404 was studied by bioinformatics and luciferase activity analysis. Our data indicated that circ_0006404 was overexpressed in HCC specimens and cells and ectopic expression of circ_0006404 increased HCC cell growth, cycle, and migration. Moreover, we showed that miR-624 was downregulated in HCC specimens and cells and miR-624 expression was negatively correlated with circ_0006404 expression in HCC specimens. Circ_0006404 sponged miR-624 in HCC cell, and the overexpression of circ_0006404 suppressed miR-624 expression in HCC cell. Furthermore, circ_0006404 induced HCC cell growth, cycle, and migration via regulating miR-624. These results elucidated that circ_0006404 facilitated HCC progression and might act as one new biomarker for this carcinoma.

Evaluation of the Synergistic Potential of Simultaneous Pan- or Isoform-Specific BET and SYK Inhibition in B-Cell Lymphoma: An In Vitro Approach

Simple Summary

B-cell lymphomas represent the majority of non-Hodgkin lymphomas and are the most common lymphoid malignancies in the Western world. Genetic alterations or epigenetic modulations can lead to tumor initiation and tumor progression. Aside from standard care, targeted, individualized therapies can be highly effective. Here, we evaluated the impact of simultaneous specific inhibition of two key regulators involved in B lymphoid tumor progression. Spleen tyrosine kinase (SYK) is a B-cell receptor-associated kinase acting as a proto-oncogene in B-cell malignancies, while bromodomain and extra-terminal domain (BET) proteins are epigenetic reader proteins involved in histone recognition and transcription regulation. The simultaneous inhibition of SYK and BET showed enhanced anti-proliferative effects, as well as inducing a distinct combination-specific gene expression profile, suggesting SYK and BET inhibition as a promising combination in the treatment of B-cell lymphoma.

Abstract

Background: Both bromodomain and extra-terminal domain (BET) proteins and spleen tyrosine kinase (SYK) represent promising targets in diffuse large B-cell (DLBCL) and Burkitt’s lymphoma (BL). We evaluated the anti-lymphoma activity of the isoform-specific bivalent BET inhibitor AZD5153 (AZD) and the pan-BET inhibitor I-BET151 (I-BET) as single agents and in combination with SYK inhibitor Entospletinib (Ento) in vitro. Methods: The effect of the single agents on cell proliferation and metabolic activity was evaluated in two DLBCL and two BL cell lines. Proliferation, metabolic activity, apoptosis, cell cycle and morphology were further investigated after a combined treatment of AZD or I-BET and Ento. RNAseq profiling of combined AZD+Ento treatment was performed in SU-DHL-4 cells. Results: Both BET inhibitors reduced cell proliferation and metabolic activity in a dose- and time-dependent manner. Combined BET and SYK inhibition enhanced the anti-proliferative effect and induced a G0/G1 cell cycle arrest. SU-DHL-4 demonstrated a pronounced modulation of gene expression by AZD, which was markedly increased by additional SYK inhibition. Functional enrichment analyses identified combination-specific GO terms related to DNA replication and cell division. Genes such as ADGRA2, MYB, TNFRSF11A, S100A10, PLEKHH3, DHRS2 and FOXP1-AS1 were identified as possible key regulators. Conclusion: Simultaneous inhibition of BET and SYK enhanced the anti-proliferative effects, and induced a combination-specific gene expression signature.

Assessment of circulating levels of microRNA-326, microRNA-424, and microRNA-511 as biomarkers for hepatocellular carcinoma in Egyptians

BACKGROUND

Hepatocellular carcinoma (HCC) is the fifth most common cancer. Differential expression of microRNAs (miRNAs)-326, miRNA-424, and miRNA-511 has been associated with the diagnosis and prognosis of HCC in different populations. However, limited information is available regarding their expression in Egyptian HCC patients.

AIM

To assess the role of circulating miRNAs-326, miRNA-424, and miRNA-511 in Egyptian HCC patients.

METHODS

This prospective observational study included 70 HCC patients and 25 healthy controls. The circulating levels of these three miRNAs were evaluated by real-time PCR. Receiver operating characteristic curve analysis was used to test the diagnostic accuracy of microRNA expression levels.

RESULTS

All miRNAs were differentially expressed in HCC patients; miRNAs326 and miRNA-424 were upregulated, while miRNA-511 was downregulated. Both miRNA-326 and miRNA-424 showed sensitivity and specificity of 97%, 71.4%, and 52%, 60%, respectively, to differentiate HCC from controls. Moreover, miRNA-326 was associated with survival and could differentiate between Child grades (A vs B); miRNA-424 significantly differentiated early vs intermediate stages of HCC; while miRNA-511 was significantly correlated with response to modified Response Evaluation Criteria in Solid Tumors (mRECIST).

CONCLUSION

We conclude that miRNA-326, miRNA-424, and miRNA-511 have diagnostic and prognostic roles in Egyptian patients with hepatitis C virus-related HCC and should be considered for better disease management.

Salivary miR-31-5p, miR-345-3p, and miR-424-3p Are Reliable Biomarkers in Patients with Oral Squamous Cell Carcinoma

If not detected early, oral squamous cell carcinoma (OSCC) has very poor prognosis, emphasizing the need for reliable early diagnostics. Saliva is considered a promising surrogate biosample for OSCC detection, because it comes into contact with many cells of the tumor mass, providing a comprehensive sampling of tumor-specific biomolecules. Although several protein- and RNA-based salivary biomarkers have been proposed for the detection of OSCC, the results of the studies show large differences. Our goal was to clarify which salivary microRNAs (miRNA) show reliably high expression in the saliva of OSCC patients, to be used as cancer-specific biomarkers, and potentially as early diagnostic biomarkers. Based on a detailed literature search, we selected six miRNAs commonly overexpressed in OSCC, and analyzed their expression in saliva samples of cancer patients and controls by real-time quantitative PCR. Our results suggest that miR-345 and miR-31-5p are consistently upregulated salivary biomarkers for OSCC, and a three-miRNA panel of miR-345, miR-31-5p, and miR-424-3p can distinguish cancer and control patients with high sensitivity.

Long Noncoding RNA NTT Context-Dependently Regulates MYB by Interacting With Activated Complex in Hepatocellular Carcinoma Cells

Background

Long noncoding RNA (lncRNA) mediates the pathogenesis of various diseases, including cancer and cardiovascular, infectious, and metabolic diseases. This study examined the role of lncRNA NTT in the development and progression of cancer.

Methods

The expression of NTT was determined using tissues containing complementary DNA (cDNA) from patients with liver, lung, kidney, oral, and colon cancers. The expression of cis-acting genes adjacent to the NTT locus (CTGF, STX7, MYB, BCLAF1, IFNGR1, TNFAIP3, and HIVEP2) was also assessed. We used knockdown and chromatin immunoprecipitation (ChIP) assays to identify the cis-acting genes that interact with NTT.

Results

NTT was most significantly downregulated in hepatocellular carcinoma (HCC), while a higher NTT level correlated with a shorter survival time of patients with HCC. Multivariate analysis indicated NTT was not an independent predictor for overall survival. MYB was significantly upregulated, and its increased expression was associated with dismal survival in HCC patients, similar to the results for NTT. NTT knockdown significantly decreased cellular migration. ChIP of HCC cell lines revealed that NTT is regulated by the transcription factor ATF3 and binds to the MYB promoter via the activated complex. Additionally, when NTT was knocked down, the expression of MYB target genes such as Bcl-xL, cyclinD1, and VEGF was also downregulated. NTT could play a positive or negative regulator for MYB with a context-dependent manner in both HCC tissues and animal model.

Conclusion

Our study suggests that NTT plays a key role in HCC progression via MYB-regulated target genes and may serve as a novel therapeutic target.

Circ-RNF13, as an oncogene, regulates malignant progression of HBV-associated hepatocellular carcinoma cells and HBV infection through ceRNA pathway of circ-RNF13/miR-424-5p/TGIF2

Circular RNA RNF13 (circ-RNF13; ID: hsa_circ_0067717) is newly identified to be abnormally upregulated in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) patients. However, its role and mechanism remain to be further annotated. First of all, real-time quantitative PCR (RT-qPCR) was utilized to examine RNA expression, and circ-RNF13 was upregulated in HBV-infected human HCC tissues and HBV-expressing cells (Huh7-HBV and Hep3B-HBV), accompanied with TGFβ-induced factor homeobox 2 (TGIF2) upregulation and microRNA (miR)-424-5p downregulation. Loss-of-functional experiments were performed using MTS assay, colony formation assay, flow cytometry, enzyme-linked immunosorbent assay, transwell assay, and xenograft tumor model. As a result, blocking circ-RNF13 enhanced the apoptosis rate of Huh7-HBV and Hep3B-HBV cells, but inhibited cell proliferation, colony formation, migration, and invasion in vitro, along with suppressed tumor growth in vivo. Besides, RT-qPCR data showed that HBV DNA copies and levels of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) were diminished by circ-RNF13 knockdown in Huh7-HBV and Hep3B-HBV cells. Mechanistically, circ-RNF13 and TGIF2 could directly interacting with miR-424-5p according to dual-luciferase reporter assay, suggesting that circ-RNF13 and TGIF2 served as competing endogenous RNAs (ceRNAs) for miR-424-5p. Functionally, overexpressing miR-424-5p mimicked and silencing miR-424-5p counteracted the effects of circ-RNF13 depletion in HBV-expressing HCC cells in vitro; TGIF2 restoration partially abrogated the role of miR-424-5p upregulation. In conclusion, circ-RNF13 might sponge miR-424-5p to suppress HBV-associated HCC cells malignant progression and HBV infection by regulating TGIF2, providing a novel insight into the occurrence and treatment of HBV-associated HCC.

Interplay between DNA Methyltransferase 1 and microRNAs During Tumorigenesis

Cancer is a genetic disease resulting from genomic changes; however, epigenetic alterations act synergistically with these changes during tumorigenesis and cancer progression. Epigenetic variations are gaining more attention as an important regulator in tumor progression, metastasis and therapy resistance. Aberrant DNA methylation at CpG islands is a central event in epigeneticmediated gene silencing of various tumor suppressor genes. DNA methyltransferase 1 (DNMT1) predominately methylates at CpG islands on hemimethylated DNA substrates in proliferation of cells. DNMT1 has been shown to be overexpressed in various cancer types and exhibits tumor-promoting potential. The major drawbacks to DNMT1-targeted cancer therapy are the adverse effects arising from nucleoside and non-nucleoside based DNMT1 inhibitors. This paper focuses on the regulation of DNMT1 by various microRNAs (miRNAs), which may be assigned as future DNMT1 modulators, and highlights how DNMT1 regulates various miRNAs involved in tumor suppression. Importantly, the role of reciprocal inhibition between DNMT1 and certain miRNAs in tumorigenic potential is approached in this review. Hence, this review seeks to project an efficient and strategic approach using certain miRNAs in conjunction with conventional DNMT1 inhibitors as a novel cancer therapy. It has also been pinpointed to select miRNA candidates associated with DNMT1 regulation that may not only serve as potential biomarkers for cancer diagnosis and prognosis, but may also predict the existence of aberrant methylation activity in cancer cells.

Role of mir-33a, mir-203b, mir361-3p, and mir-424 in hepatocellular carcinoma

Background/aim

Hepatocellular carcinoma (HCC) is one of the most aggressive cancer types. MicroRNAs (miRNAs) are small noncoding regulatory RNAs that function posttranscriptionally. miRNA deregulation was observed in the development and progression of HCC. In this study, we aimed to investigate the expression levels of four miRNAs (mir-33a, mir-203b, mir361-3p, and mir-424) in HCC patients in comparison to healthy individuals.

Materials and methods

Venous blood samples were collected from both HCC patients and healthy individuals. In order to determine the relative expression levels of mir-33a, mir-203b, mir361-3p, and hsa-mir-424 in HCC patients, probe-based quantitative real time PCR (qRT-PCR) was performed. The cycle threshold (Ct) results were analyzed according to the 2−∆∆Ct method and statistical analyses were performed by SPSS Statistics version 15 for Windows.

Results

qRT-PCR analysis revealed that the expression levels of mir-33a (fold change: 7.3 and P < 0.001), mir-203b (fold change: 4.6 and P < 0.001), and mir361-3p (fold change: 5.1 and P < 0.001)were downregulated compared to healthy individuals and mir-424 did not show any significant change between HCC patients and controls.

Conclusion

Our results indicated that mir-33a, mir-203b, and mir-361-3p may significantly contribute to tumor pathogenesis in HCC and have potential to be used as a noninvasive biomarker for cancer therapy.

Extracellular vesicle-encapsulated microRNA-424 exerts inhibitory function in ovarian cancer by targeting MYB

Background

Recent studies have suggested a crucial role of mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) in ovarian cancer treatment. We, therefore, set out to explore the mechanism through which MSC-derived EVs delivered microRNA-424 (miR-424) to influence the development of ovarian cancer.

Methods

Bioinformatics analyses were first performed to screen ovarian cancer-related differentially expressed genes and to predict regulatory miRNAs. Then, dual-luciferase reporter gene assay was carried out to verify the relationship between miR-424 and MYB. Subsequently, the characterized MSCs and isolated EVs were co-cultured with ovarian cancer cells, followed by determination of the expression patterns of miR-424, MYB, vascular endothelial growth factor (VEGF), and VEGF receptor (VEGFR), respectively. In addition, the effects of EVs-delivered miR-424 on the proliferation, migration, invasion and tube formation of ovarian cancer cells were assessed using gain- and loss-of-function approaches. Lastly, tumor xenograft was induced in nude mice to illustrate the influence of EVs-loaded miR-424 on ovarian cancer in vivo.

Results

Our data exhibited that MYB was highly-expressed and miR-424 was poorly-expressed in ovarian cancer. More importantly, MYB was identified as a target gene of miR-424. Additionally, the transfer of miR-424 by MSC-derived EVs was found to repress the proliferation, migration, and invasion of ovarian cancer cells, with a reduction in the expressions of VEGF and VEGFR. Furthermore, MSC-derived EVs over-expressing miR-424 could inhibit the proliferation, migration, and tube formation of human umbilical vein endothelial cells, and also suppressed tumorigenesis and angiogenesis of ovarian tumors in vivo.

Conclusion

Collectively, our findings indicate that MSC-derived EVs transfer miR-424 to down-regulate MYB, which ultimately led to the inhibition of the tumorigenesis and angiogenesis of ovarian cancer. Hence, this study offers a potential prognostic marker and a therapeutic target for ovarian cancer.

Ropivacaine inhibits proliferation, migration, and invasion while inducing apoptosis of glioma cells by regulating the SNHG16/miR-424-5p axis

BACKGROUND

Regional anesthesia has anti-proliferative and pro-apoptotic effects in various cancers. Therefore, the purpose of this study was to investigate the effects of ropivacaine on the proliferation, migration, invasion, and apoptosis of glioma cells in vitro.

METHODS

Under ropivacaine stimulation conditions, proliferation, apoptosis, migration, and invasion of glioma cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazol-3-ium bromide (MTT), flow cytometry, and transwell assays, respectively. Western blot assay was employed to measure the protein expression levels in glioma cells. The expression levels of small nucleolar RNA host gene 16 (SNHG16) and miR-424-5p were assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The interaction relationship between SNHG16 and miR-424-5p was predicted and confirmed using a bioinformatics database and dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull-down assays.

RESULTS

After treatment with ropivacaine, proliferation, migration, and invasion were repressed while apoptosis was enhanced in glioma cells in a dose-depended manner. In addition, ropivacaine impeded SNHG16 expression in glioma cells. Importantly, overexpression of SNHG16 abolished the ropivacaine-induced effects on glioma cells. Analogously, knockdown of miR-424-5p counteracted the function of ropivacaine in glioma cells. We also found that SNHG16 bound to miR-424-5p and negatively regulated miR-424-5p expression in glioma cells. The rescue experiments indicated that ropivacaine might regulate glioma progression by targeting the SNHG16/miR-424-5p axis.

CONCLUSION

Our findings revealed the anti-tumor effects of ropivacaine in glioma by targeting the SNHG16/miR-424-5p axis. These data might extend the understanding of regulatory mechanisms by which ropivacaine could suppress glioma development.

The microRNA-424/503 cluster: A master regulator of tumorigenesis and tumor progression with paradoxical roles in cancer

MicroRNAs (miRNAs) are a group of non-coding RNAs that play a crucial role in post-transcriptional gene regulation and act as indispensable mediators in several critical biological processes, including tumorigenesis, tissue homeostasis, and regeneration. MiR-424 and miR-503 are intragenic miRNAs that are clustered on human chromosome Xq26.3. Previous studies have reported that both miRNAs are dysregulated and play crucial but paradoxical roles in tumor initiation and progression, involving different target genes and molecular pathways. Moreover, these two miRNAs are concomitantly expressed in several cancer cells, indicating a coordinating function as a cluster. In this review, the roles and regulatory mechanisms of miR-424, miR-503, and miR-424/503 cluster are summarized in different types of cancers.

MiR-424-5p regulates cell cycle and inhibits proliferation of hepatocellular carcinoma cells by targeting E2F7

Objective

This study aims to explore the mechanism of the miR-424-5p/E2F7 axis in hepatocellular carcinoma (HCC) and provide new ideas for targeted therapy of HCC.

Methods

Bioinformatics analysis was used to identify the target differentially expressed miRNA in HCC and predict its target gene. qRT-PCR was employed to verify the expression of miR-424-5p and E2F7 mRNA in HCC cells. Western blot was performed to detect the effect of miR-424-5p ectopic expression on the protein expression of E2F7. CCK-8 was used to detect proliferative activity of HCC cells and flow cytometry was carried out for analyzing cell cycle distribution. Dual luciferase reporter assay was conducted to verify the direct targeting relationship between miR-424-5p and E2F7.

Results

We observed that miR-424-5p was down-regulated in HCC cells. CCK-8 showed that overexpression of miR-424-5p inhibited cell proliferation, and flow cytometry showed that miR-424-5p could block cells in G0/G1 phase. E2F7 was up-regulated in HCC cells, and E2F7 overexpression could facilitate the proliferative ability of HCC cells and promote the cell cycle progressing from G0/G1 to S phase. Furthermore, dual-luciferase reporter assay indicated that miR-424-5p could directly down-regulate E2F7 expression. Analysis on cell function demonstrated that miR-424-5p inhibited the proliferation of HCC cells and blocked cell cycle at G0/G1 phase by targeting E2F7.

Conclusion

Our results proved that E2F7 was a direct target of miR-424-5p, and miR-424-5p could regulate cell cycle and further inhibit the proliferation of HCC cells by targeting E2F7.

Role of miRNA-424 in Cancers

microRNA (miRNA) is an important part of non-coding RNA that regulates gene expression at a posttranscriptional level. miRNA has gained increasing interest in recent years, both in research and clinical fields. miRNAs have been found to play an important role in various diseases, particularly cancer. Aberrant miR-424 expression is found in several tumors where they can function as either oncogenes or tumor-suppressor genes. Meanwhile, miR-424 is also affected by the reorganization of many other non-coding RNAs such as lncRNA and cirRNA. Several studies have found that miR-424 participates in proliferation, differentiation, apoptosis, invasion, angiogenesis, and drug resistance, and plays an important role in the tumorigenesis and progression of tumors. This review will focus on the recent progress of research on miR-424 in tumors.

Construction of a potential microRNA, transcription factor and mRNA regulatory network in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and the third leading cause of cancer-related death. MicroRNAs and transcription factors (TFs) cooperate to regulate the same target gene, thus affecting the progression of HCC.

Methods

Differentially expressed miRNAs and mRNAs were screened. Functional enrichment analysis of these HCC-related mRNAs was performed, and a protein-protein interaction network was constructed. TFs that regulate these miRNAs and hub genes were also screened.

Results

Ten differentially upregulated miRNAs and 5 differentially downregulated miRNAs were screened. Additionally, 183 downregulated mRNAs and 303 upregulated mRNAs that are potentially bound to these differentially expressed miRNAs were identified. The Kyoto Encyclopedia of Genes and Genomes (KEGG) results showed that the differentially expressed mRNAs were significantly enriched in pathways in cancer, the Wnt signaling pathway, and the Rap1 signaling pathway. Then, 220 TFs were identified for 5 candidate genes of the downregulated mRNAs, and 258 TFs were identified for 9 candidate genes of the upregulated mRNAs. Finally, the 9 upregulated hub genes were related to higher overall survival (OS) in the low-expression group, and 4/5 downregulated hub genes were related to higher OS in the high-expression group.

Conclusions

This study constructed a potential regulatory network between candidate molecules and that need to be further verified. These regulatory relationships are expected to clarify the new molecular mechanisms of the occurrence and development of HCC.

miR-424-5p regulates cell proliferation and migration of esophageal squamous cell carcinoma by targeting SIRT4

Objective: The present research is aimed to elucidate the expression patterns of miR-424-5p and its role in tumorigenesis and progression of esophageal squamous cell carcinoma (ESCC).

Methods: Both starBase and TCGA were utilized to assess miR-424-5p expression status in ESCC. The endogenous mRNA expression levels of miR-424-5p in ESCC and normal esophagus cell lines were detected by qRT-PCR. CCK8 and colony-forming assays were applied to determine the effects of miR-424-5p on ESCC proliferation. Transwell migration and wound healing assays were carried out to observe the changes of ESCC cell mobility after miR-424-5p mimic or inhibitor transfection. Impact of miR-424-5p on malignancy growth in vivo was further verified in a mouse xenograft model. The regulatory relationships between miR-424-5p and SIRT4 were validated by dual luciferase reporter assay, qRT-PCR and Western blot.

Results: miR-424-5p expression was found upregulated in ESCC. miR-424-5p overexpression dramatically facilitated ESCC cells proliferation and migration capacity in vitro, while downregulation of miR-424-5p displayed the opposite trend. Inhibition of xenograft tumor growth was further evidenced in vivo. Moreover, SIRT4 was confirmed to be a specific target gene of miR-424-5p in ESCC and negatively modulated by miR-424-5p. Finally, SIRT4 overexpression strongly rescued the promoting influence of miR-424-5p on the proliferative and migratory capacity of ESCC cells.

Conclusions: miR-424-5p had tumor promoting functions in proliferation and migration of ESCC by targeting SIRT4, suggesting that miR-424-5p may serve as a potential diagnostic biomarker and manipulation of miR-424-5p/SIRT4 axis could provide a novel therapeutic strategy for further ESCC treatment.

Cyto-biological effects of microRNA-424-5p on human colorectal cancer cells

MicroRNA (miR)-424-5p is overexpressed in colorectal cancer (CRC); however, its role, clinical significance and underlying molecular mechanism have remained to be fully elucidated. The aim of the present study was to investigate the roles of miR-424-5p in CRC and the underlying mechanisms. It was demonstrated that miR-424-5p is overexpressed in CRC, based on bioinformatics analysis using The Cancer Genome Atlas TCGA and analysis of tissue samples from patients with CRC from The First Hospital of Hebei Medical University, and the expression of miR-424-5p was associated with the depth of invasion and Dukes' staging. In CRC cells, the oncogenic roles of miR-424-5p were also verified by Cell Counting Kit-8, wound healing and Transwell assays. To identify target genes, all transcripts were compared between miR-424-5p mimic-transfected SW480 cells and mimic control cells by transcriptome sequencing. Subsequently, the differentially expressed genes (DEGs) were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The DEGs were revealed to be significantly enriched in the GO terms 'serine hydrolase activity,' 'serine-type peptidase activity' and 'serine-type endopeptidase activity'. KEGG signaling pathway analysis indicated that the DEGs were significantly enriched in 'endocytosis', 'regulation of actin cytoskeleton', 'Wnt signaling pathway' and 'ubiquitin-mediated proteolysis signaling pathway'. These results suggested that miR-424-5p is a potential target in the treatment of CRC.

HIF-1α-dependent miR-424 induction confers cisplatin resistance on bladder cancer cells through down-regulation of pro-apoptotic UNC5B and SIRT4

Background

Chemo-resistance of bladder cancer has been considered to be one of the serious issues to be solved. In this study, we revealed pivotal role of miR-424 in the regulation of CDDP sensitivity of bladder cancer cells.

Methods

The cytotoxicity of cisplatin and effect of miR-424 were assessed by flow cytometry and TUNEL. Transcriptional regulation of miR-424 by HIF-1α was assessed by Chromatin immunoprecipitation (ChIP). Effect of miR-424 on expression of UNC5B, SIRT4 (Sirtuin4) and apoptotic markers was measured by QRT-PCR and/or Western blot. The regulation of miR-424 for UNC5B and SIRT4 were tested by luciferase reporter assay. The 5637-inoculated nude mice xenograft model was used for the in vivo study. The clinical significance of miR-424 was demonstrated mainly through data mining and statistical analysis of TCGA.

Results

In this study, we have found for the first time that cisplatin (CDDP) induces the expression of miR-424 in a HIF-1α-dependent manner under normoxia, and miR-424 plays a vital role in the regulation of CDDP resistance of bladder cancer cells in vitro. Mechanistically, we have found that UNC5B and SIRT4 are the direct downstream target genes of miR-424. CDDP-mediated suppression of xenograft bladder tumor growth was prohibited by the addition of miR-424, whereas ectopic expression of UNC5B or SIRT4 partially restored miR-424-dependent decrease in CDDP sensitivity of bladder cancer 5637 and T24 cells. Moreover, knockdown of UNC5B or SIRT4 prohibited CDDP-mediated proteolytic cleavage of PARP and also decreased CDDP sensitivity of these cells. Consistently, the higher expression levels of miR-424 were closely associated with the poor clinical outcome of the bladder cancer patients. There existed a clear inverse relationship between the expression levels of miR-424 and pro-apoptotic UNC5B or SIRT4 in bladder cancer tissues.

Conclusions

Collectively, our current results strongly suggest that miR-424 tightly participates in the acquisition/maintenance of CDDP-resistant phenotype of bladder cancer cells through down-regulation of its targets UNC5B and SIRT4, and thus combination chemotherapy of CDDP plus HIF-1α/miR-424 inhibition might have a significant impact on hypoxic as well as normoxic bladder cancer cells.

MicroRNA-294 Promotes Cell Proliferation, Migration and Invasion in SMMC-7721 Hepatoma Carcinoma Cells by Activating the JNK/ERK Signaling Pathway

BACKGROUND

It has been reported that miR-294 is highly expressed in hepatocellular carcinoma (HCC) tissues and cells. However, the potential role of miR-294 in the pathogenesis of HCC remains unclear. This study aimed to explore the role of miR-294 in HCC and the potential mechanism involved in this process.

MATERIALS AND METHODS

Reverse transcription polymerase chain reaction was performed to determine the expression of miR-294 in HCC tissues and cell lines. Following the overexpression or knockdown of miR-294, the proliferation, migration, and invasion abilities of cells were determined using Cell Counting Kit-8 (CCK-8), wound healing and transwell assays, respectively. The phosphorylation of JNK and ERK was determined through western blotting. Furthermore, HCC cells were treated with JNK inhibitor SP600125 or ERK inhibitor U0126 and transfected with miR-294 mimics or negative control. Subsequently, the phosphorylation of JNK and ERK was evaluated and the proliferation, migration and invasion abilities of HCC cells were also determined.

RESULTS

The expression of miR-294 was significantly increased in HCC tissues and cell lines. Following the overexpression of miR-294, proliferation, migration, and invasion were promoted in the SSMC-7721 cell line, and the phosphorylation of JNK and ERK was increased, while silencing of miR-294 led to the opposite result. Use of the JNK or ERK inhibitor to treat SSMC-7721 cells transfected with miR-294 mimics decreased the phosphorylation of JNK and ERK and inhibited the proliferation, migration and invasion abilities of cells.

CONCLUSIONS

miR-294 is important for the development of HCC in terms of the biological activities of cells, and may be a novel therapeutic target for HCC.

MACC1-AS1 promotes hepatocellular carcinoma cell invasion and proliferation by regulating PAX8

Long noncoding RNAs play vital roles in several biological processes, including cell growth and embryonic development. We showed that MACC1-AS1 was overexpressed in hepatocellular carcinoma (HCC) cells and tissues. The MACC1-AS1 expression level was dramatically upregulated in HCC samples compared to adjacent normal samples, and 77.5% (31 of 40) of HCC samples showed overexpression of MACC1-AS1. Ectopic MACC1-AS1 expression enhanced cell proliferation and cyclin D1 expression in both SMMC7721 and MHCC-97H cells. Ectopic expression of MACC1-AS1 promoted vimentin, N-cadherin and snail expression and decreased E-cadherin expression in both SMMC7721 and MHCC-97H cells. MACC1-AS1 overexpression also induced cell invasion in the same two cell lines. Furthermore, MACC1-AS1 overexpression enhanced PAX8 expression in HCC cells. The PAX8 level was dramatically increased in HCC samples compared to adjacent normal samples, and 75% (30 of 40) of HCC samples showed overexpression of PAX8. PAX8 expression was positively correlated with MACC1-AS1 expression in HCC samples. MACC1-AS1 overexpression promoted HCC cell proliferation, EMT and invasion through regulating PAX8. These results suggest that MACC1-AS1 acts as an oncogene in the development of HCC.

Differential expression of angiogenesis-related miRNAs and VEGFA in cirrhosis and hepatocellular carcinoma

INTRODUCTION

Liver cirrhosis (LC) is a heterogeneous liver disease, the last stage of liver fibrosis, and the major risk factor for hepatocellular carcinoma (HCC). Our study aimed to evaluate the expression of microRNAs and the endothelial vascular growth factor (VEGFA) gene in LC and HCC.

MATERIAL AND METHODS

The sample group consisted of 46 tissue samples: 21 of LC, 15 of HCC, and 10 of non-tumoural and non-cirrhotic liver tissue (control group). MiRNAs were chosen based on a mirDIP prediction database as regulators of the VEGFA gene. Gene expression of VEGF and miRNAs was quantified by real-time quantitative polymerase chain reaction. VEGFA protein expression was evaluated by ELISA.

RESULTS

VEGFA gene expression was significantly overexpressed in LC compared to the control group (p < 0.0001). Hsa-miR-206 (p = 0.0313) and hsa-miR-637 (p = 0.0156) were down-expressed in LC. In HCC, hsa-miR-15b (p = 0.0010), hsa-miR-125b (p = 0.0010), hsa-miR-423-3p (p = 0.0010), hsa-miR-424 (p = 0.0313), hsa-miR-494 (p < 0.0001), hsa-miR-497 (p < 0.0001), hsa-miR-612 (p = 0.0078), hsa-miR-637 (p < 0.0001), and hsa-miR-1255b (p = 0.0156) presented down-expression.

CONCLUSIONS

Overexpression of VEGFA in LC suggests impairment of angiogenesis in this tissue. The differential expression of microRNAs in LC and HCC observed in our study can lead to the evaluation of possible biomarkers for these diseases.

MicroRNA-802 induces hepatitis B virus replication and replication through regulating SMARCE1 expression in hepatocellular carcinoma

Growing evidences have indicated that microRNAs (miRNAs) can regulate hepatitis B virus (HBV) expression and replication, playing crucial roles in the development of HBV infection. Until now, the functional role and mechanism of miR-802 in HBV replication and expression remain unknown. We indicated that miR-802 expression was upregulated in the HBV-associated hepatocellular carcinoma (HCC) tissues compared with the adjacent noncancerous samples. In addition, we showed that the SMARCE1 expression level was downregulated in the HBV-associated HCC tissues compared with the adjacent noncancerous samples. miR-802 expression was negatively related with MARCE1 expression in HBV-associated HCC tissues. Moreover, miR-802 expression was upregulated, and SMARCE1 expression was downregulated in the HBV-infected HepG2.2.15 cells. Ectopic expression of miR-802 significantly enhanced HBV DNA replication, while knockdown of miR-802 significantly decreased HBV DNA replication. We showed that overexpression of miR-802 promoted HbsAg and HbeAg expression, while inhibition of miR-802 decreased HbsAg and HbeAg expression. Furthermore, we indicated that ectopic expression of SMARCE1 suppressed HBV DNA replication and decreased the expression level of HbsAg and HbeAg. Finally, we showed that overexpression of miR-802 promoted HBV DNA replication through regulating SMARCE1 expression. These results suggested the important roles of miR-802 on HBV expression and replication, which may shed new light on the development of treatment for HBV.

MicroRNA-424 regulates cisplatin resistance of gastric cancer by targeting SMURF1 based on GEO database and primary validation in human gastric cancer tissues

Purpose

Cisplatin (DDP) based chemotherapy regimens are widely used in advanced gastric cancer (GC). Drug resistance often limited the clinical benefits of cisplatin regimen. The mechanisms of cisplatin resistance have not been fully revealed. Therefore, further exploration of the relevant molecular mechanisms is urgently needed.

Patients and methods

DDP resistance associated miRNA of GC microarray dataset GSE86195 was obtained from the National Center for Biotechnology Information (NCBI) GEO database, GEO2R was applied to compare the samples in two different groups under the same experimental conditions. |log₂(Fold Change) | (log₂(FC)) was selected as the criteria to screen the statistically significant DE-miRNAs. StarBaseV3.0 was used to predict the target genes of the DE-miRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of target genes of DE-miRNAs were carried out using DAVID. The STRING database was applied to estimate the correlations between target genes. Analysis of hubgenes by coremine and The Human Protein Atlas (THPA). Initial expression validations of miR-424 and miR-491-5p, SMURF1 and BCL2L1 were carried out using clinical pathological specimens by RT-PCR.

Results

A total of 13 Differential expression-miRNAs (DE-miRNAs) were identified in DDP chemoresistant cells, including 9 upregulated miRNAs and 4 downregulated miRNAs. SMURF1 and BCL2L1 were screened as the critical genes in DDP-resistant GC, which were regulated by miR-424 and miR-491-5p respectively. The results of validation of hub genes expression in GC tissues indicated that in DFS<1-year group, the expression of miR-424 decreased significantly, notably upregulated expression of SMURF1 was also detected.

Conclusion

Our results implied that miR-424, as a tumor suppressor, could deregulate SMURF1 in DDP-resistant GC cells.

miR-424-5p Regulates Hepatoma Cell Proliferation and Apoptosis

OBJECTIVE

Yes-associated protein (Yes-associated protein 1 [YAP1]) is an important oncogene that is related to the pathogenesis and progression of liver cancer. It was found that miR-424-5p expression was significantly decreased in liver cancer tissues, revealing its anticancer effect. Bioinformatic analysis demonstrated the targeted relationship between miR-424-5p and the 3' untranslated region of YAP1. This study investigated the role of miR-424-5p in regulating YAP1 expression and affecting hepatoma cell proliferation and apoptosis.

MATERIALS AND METHODS

Tumors and normal liver tissues adjacent to tumors were collected from patients to detect the expression of miR-424-5p and YAP1. A dual-luciferase reporter gene assay was adopted to explore the targeted regulation between miR-424-5p and YAP1. Liver cancer HCCLM3 and MHCC97-L cells and normal liver HL-7702 cells were cultured in vitro to compare expression levels of miR-424-5p and YAP1. HCCLM3 and MHCC97-L cells were divided into the miR-NC group and miR-424-5p mimic group. Cell apoptosis was detected by flow cytometry. Cell proliferation was determined by EdU staining.

RESULTS

Compared with normal liver tissue, miR-424-5p expression was significantly decreased, while YAP1 mRNA and protein levels were obviously upregulated in liver cancer tissues, which were related to the clinical stage. A negative correlation was found between miR-424-5p and YAP1 mRNA levels in liver cancer tissues. Dual-luciferase reporter gene assay confirmed the targeted relationship between miR-424-5p and YAP1. miR-424-5p expression in HCCLM3 and MHCC97-L cells decreased compared with L20 cells, which correlated with malignancy. YAP1 level in HCCLM3 and MHCC97-L cells was significantly enhanced, which correlated with malignancy. miR-424-5p mimic transfection significantly downregulated YAP1 expression in HCCLM3 and MHCC97-L cells, resulting in enhanced apoptosis and attenuated cell proliferation.

CONCLUSIONS

Decreased miR-424-5p expression and increased YAP1 expression are found in patients with liver cancer. Increased miR-424-5p can inhibit YAP1 expression, attenuate hepatoma cell proliferation, and induce cell apoptosis.

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.

miR-202 modulates the progression of neuropathic pain through targeting RAP1A

Neuropathic pain is a somatosensory disorder which is caused by disease or nerve injury that affects the nervous system. microRNAs (miRNAs) are proved to play crucial roles in the development of neuropathic pain. However, the role of miR-202 in neuropathic pain is still unknown. Sprague-Dawley rats were used for constructing the neuropathic pain model. The expression of miR-202 was determined by quantitative real-time polymerase chain reaction. Potential target gene for miR-202 was measured using bioinformatics methods and Western blot analysis. In this study, we used rats to establish a neuropathic pain model and measured the effect of miR-202 in neuropathic pain. We demonstrated that miR-202 expression was downregulated in the spinal dorsal horn of bilateral sciatic nerve chronic constriction injury (bCCI) rat. However, miR-202 expression was not changed in the dorsal root ganglion, hippocampus, and anterior cingulated cortex of bCCI rat. We identified that RAP1A was a direct target gene of miR-202 in the PC12 cell. RAP1A expression was upregulated in the spinal dorsal horn of bCCI rat. Overexpression of miR-202 could improve the pain threshold for bCCI rats in both hindpaws, indicating that miR-202 overexpression could lighten the pain threshold for model rats. Moreover, RAP1A overexpression increased the pain threshold effect of miR-202 overexpression treated bCCI rats, indicating that miR-202 could lighten the pain threshold through inhibiting RAP1A expression. These data suggested that miR-202 acted pivotal roles in the development of neuropathic pain partly through targeting RAP1A gene.

miR-424 targets AKT3 and PSAT1 and has a tumor-suppressive role in human colorectal cancer

Background

Recent advances in cancer biology have uncovered critical roles for microRNAs in regulating tumor responses. This study is to elucidate the role of miR-424 in colorectal cancer development.

Materials and methods

miR-424 expression was analyzed by qRT-PCR. The role of miR-424 was studied in cell lines and animal models. The downstream targets of miR-424 were determined by microarray analysis.

Results

We found that miR-424 expression was downregulated in human colorectal cancer cell lines and patient biopsies. We demonstrated that miR-424 functioned as a tumor suppressor by suppressing colorectal cancer growth in vitro and in vivo and enhancing apoptosis. Using microarray screening, we subsequently presented evidence that miR-424 directly targeted the 3′ untranslated regions of the AKT serine/threonine kinase 3 (AKT3) and phosphoserine aminotransferase 1 (PSAT1) mRNAs via luciferase assay. Furthermore, AKT3 or PSAT1 silencing partially recapitulated the effects of miR-424.

Conclusion

This newly identified miR-424/AKT3–SAT1 axis may represent a novel therapeutic strategy for future treatment of colorectal cancer.

miR-424 coordinates multilayered regulation of cell cycle progression to promote esophageal squamous cell carcinoma cell proliferation

BACKGROUND

Dysregulation of the cell cycle has been implicated in esophageal squamous cell carcinoma (ESCC) progression. This study aimed to evaluate the role of miR-424 in cell cycle regulation and ESCC proliferation.

METHODS

The role of miR-424 in cell proliferation was evaluated in vitro and in vivo. Transcriptional activation of miR-424 was determined using chromatin immunoprecipitation, and binding of miR-424 to targets was verified using miRNA ribonucleoprotein complex immunoprecipitation.

FINDINGS

miR-424 was upregulated and correlated with poor survival in ESCC patients. Repression or overexpression of miR-424 respectively decreased or increased ESCC cell proliferation in vitro and in vivo. miR-424 expression is transcriptionally regulated by E2F1 and increased during G1/S transition. Knockdown or overexpression of miR-424 respectively inhibited or promoted both G1/S and G2/M cell cycle transitions in ESCC cells, and these effects were mediated by two newly identified miR-424 targets, PRKCD and WEE1, respectively. Consequently, elevation of PRKCD by miR-424 knockdown led to enhanced stability of the p21Cip1 protein via increased activation of PRKCD and downstream p38 MAPK and JNK signaling to block CDK2 activation and G1/S transition, while elevated WEE1 maintained CDC2 in an inactive state to block G2/M transition. However, circLARP4 could sponge the binding of miR-424 to PRKCD, thus compromising the regulation of G1/S progression by miR-424.

INTERPRETATION

miR-424 coordinates a previously unknown, multilayered regulation of ESCC cell cycle progression to promote ESCC proliferation, and may be used as a novel prognostic marker and an effective therapeutic target for ESCCs. FUND: National Natural Science Foundation of China.

LINC01287 regulates tumorigenesis and invasion via miR-298/MYB in hepatocellular carcinoma

Recently, it was reported that long non‐coding RNAs (lncRNAs) participated in promoting hepatocellular carcinoma (HCC) initiation and progression. Herein, we reported that the expression level of LINC01287 was elevated in HCC cell lines and tissues. LINC01287 down‐regulation inhibited HCC cells growth and invasion both in vitro and in vivo. LINC01287 exerted as a ceRNA and negatively regulated miR‐298 expression. MYB was identified as a downstream target of miR‐298. The miR‐298/MYB axis mediated LINC01287's effect on HCC. To the best of our knowledge, our findings provided the first evidence that LINC01287 functioned as an oncogene in HCC. LINC01287 may be a candidate prognostic biomarker and a target for new therapies in HCC patients.

Comprehensive analysis of key genes, microRNAs and long non-coding RNAs in hepatocellular carcinoma

Human hepatocellular carcinoma (HCC) is a common aggressive cancer whose molecular mechanism remains elusive. We aimed to identify the key genes, microRNAs (miRNAs) and long non‐coding RNAs (lncRNAs) involved with HCC. We obtained mRNA, miRNA and lncRNA profiles for HCC from The Cancer Genome Atlas and then identified differentially expressed mRNAs (DEmRNAs), miRNAs (DEmiRNAs) and lncRNAs (DElncRNAs). We performed functional annotation of DEmRNAs and then constructed HCC‐specific DEmiRNA–DEmRNA, DEmiRNA–DElncRNA and DElncRNA–DEmiRNA–DEmRNA interaction networks. We searched for nearby target cis‐DEmRNAs of DElncRNAs and performed receiver operating characteristic and survival analyses. A total of 1239 DEmRNAs, 33 DEmiRNAs and 167 DElncRNAs in HCC were obtained. Retinol metabolism [false discovery rate (FDR) = 7.02 × 10⁻¹⁴] and metabolism of xenobiotics by cytochrome P450 (FDR = 7.30 × 10⁻¹¹) were two significantly enriched pathways in HCC. We obtained 545 DEmiRNA–DEmRNA pairs that consisted of 258 DEmRNAs and 28 DEmiRNAs in HCC. mir‐424, miR‐93 and miR‐3607 are three hub DEmiRNAs of the HCC‐specific DEmiRNA–DEmRNA interaction network. HAND2‐AS1/ENSG00000232855–miR‐93–LRAT/RND3, ENSG00000232855–miR‐877–RCAN1 and ENSG00000232855–miR‐224–RND3 interactions were found in the HCC‐specific DElncRNA–DEmiRNA–DEmRNA interaction network. A total of three DElncRNA–nearby target DEmRNA pairs (HCG25–KIFC1, LOC105378687–CDC20 and LOC101927043–EPCAM) in HCC were obtained. Diagnostic and prognostic values of several selected DElncRNAs, DEmRNAs and DEmiRNAs for HCC were assessed. Our study identified several DEmRNAs, DEmiRNAs and DElncRNAs with great diagnostic or prognostic value for HCC, which may facilitate studies into the molecular mechanisms, and development of potential biomarkers and therapeutic target sites for HCC.

LncRNA HOXA11-AS promotes hepatocellular carcinoma progression by repressing miR-214-3p

Accumulating studies supported that lncRNAs played important roles in tumorigenesis. LncRNA HOXA11‐AS was a novel lncRNA that has been proved to involved in several tumours. However, the role of HOXA11‐AS in the development of hepatocellular carcinoma (HCC) remains to be explained. In our study, we showed that HOXA11‐AS expression was up‐regulated in the HCC tissues, and the higher expression of HOXA11‐AS was associated with the advanced stage in the HCC samples. In addition, we indicated that the expression of HOXA11‐AS was up‐regulated in HCC cell lines (Hep3B, SMMC‐7721, MHCC97‐H and BEL‐7402) compared with normal liver cell lines (HL‐7702). Overexpression of HOXA11‐AS promoted HCC proliferation and invasion and induced the epithelial‐mesenchymal transition (EMT) and knockdown of HOXA11‐AS suppressed the HCC cell proliferation and invasion. However, we showed that miR‐214‐3p expression was down‐regulated in the HCC tissues and cell lines. Ectopic expression of miR‐214‐3p suppressed HCC cell proliferation and invasion. Furthermore, we indicated that overexpression of HOXA11‐AS decreased the miR‐214‐3p expression and the expression of miR‐214‐3p was negatively related with the HOXA11‐AS expression in HCC samples. Ectopic expression of HOXA11‐AS increased HCC proliferation and invasion and induced EMT through inhibiting miR‐214‐3p expression. These data suggested that HOXA11‐AS/miR‐214‐3p axis was responsible for development of HCC.

miR-150 Suppresses Tumor Growth in Melanoma Through Downregulation of MYB

miR-150 has been demonstrated to inhibit tumor progression in various human cancers, including colorectal cancer, ovarian cancer, and thyroid cancer. However, the role of miR-150 in melanoma remains to be determined. In this study, we found that miR-150 was underexpressed in melanoma tissues and cell lines. Through transfection of miR-150 mimics, we found that miR-150 significantly inhibited the proliferation, migration, and invasion of melanoma cells. In mechanism, we found that MYB was a target of miR-150 in melanoma cells. Overexpression of miR-150 significantly inhibited mRNA and protein levels of MYB in melanoma cells. Moreover, there was an inverse correlation between the expression of miR-150 and MYB in melanoma tissues. We also showed that MYB was upregulated in melanoma tissues and cell lines. Through functional experiments, we found that restoration of MYB in miR-150-overexpressed melanoma cells rescued the proliferation, migration, and invasion. Therefore, our findings demonstrated that miR-150 suppressed the proliferation, migration, and invasion of melanoma cell by downregulating MYB.

Transcription and microRNA Profiling of Cultured Human Tympanic Membrane Epidermal Keratinocytes

The human tympanic membrane (TM) has a thin outer epidermal layer which plays an important role in TM homeostasis and ear health. The specialised cells of the TM epidermis have a different physiology compared to normal skin epidermal keratinocytes, displaying a dynamic and constitutive migration that maintains a clear TM surface and assists in regeneration. Here, we characterise and compare molecular phenotypes in keratinocyte cultures from TM and normal skin. TM keratinocytes were isolated by enzymatic digestion and cultured in vitro. We compared global mRNA and microRNA expression of the cultured cells with that of human epidermal keratinocyte cultures. Genes with either relatively higher or lower expression were analysed further using the biostatistical tools g:Profiler and Ingenuity Pathway Analysis. Approximately 500 genes were found differentially expressed. Gene ontology enrichment and Ingenuity analyses identified cellular migration and closely related biological processes to be the most significant functions of the genes highly expressed in the TM keratinocytes. The genes of low expression showed a marked difference in homeobox (HOX) genes of clusters A and C, giving the TM keratinocytes a strikingly low HOX gene expression profile. An in vitro scratch wound assay showed a more individualised cell movement in cells from the tympanic membrane than normal epidermal keratinocytes. We identified 10 microRNAs with differential expression, several of which can also be linked to regulation of cell migration and expression of HOX genes. Our data provides clues to understanding the specific physiological properties of TM keratinocytes, including candidate genes for constitutive migration, and may thus help focus further research.

miR-424-5p regulates cell proliferation, migration and invasion by targeting doublecortin-like kinase 1 in basal-like breast cancer

Our previous study has showed doublecortin like kinase 1 (DCLK1) serves as an oncogene to regulate basal-like breast cancer cell proliferation, migration and invasion, and is associated with malignant status and poor prognosis. The aim of this study is to identify microRNAs (miRNAs), which target DCLK1 to regulate basal-like breast cancer cell proliferation, migration and invasion. In our results, we observed that miR-424-5p expression was decreased in basal-like breast cancer tissues and cell lines. Furthermore, we found 3'-UTR of DCLK1 had binding site of miR-424-5p based on microRNA target databases, and there was an inverse correlation between miR-424-5p and DCLK1 in basal-like breast cancer tissues. Moreover, we confirmed miR-424-5p directly targeted to 3'-UTR of DCLK1 through luciferase reporter assay, and miR-424-5p negatively regulated DCLK1 mRNA and protein expressions through qRT-PCR and western blot. The gain-of-function studies showed that miR-424-5p suppressed basal-like breast cancer cell proliferation, migration and invasion. The rescued-function studies suggested up-regulation of DCLK1 could rescue inhibition of miR-424-5p mimics in the regulation of basal-like breast cancer cell proliferation, migration and invasion. Finally, low-expression of miR-424-5p was associated with advanced clinical stage, large tumor size, more metastatic lymph nodes, present distant metastasis and poor histological grade in basal-like breast cancer patients. In conclusion, miR-424-5p is a tumor suppressive microRNA to regulate tumor cell proliferation, migration and invasion via binding to the functional target DCLK1, and associated with malignant status in basal-like breast cancer.

Expression analysis of liver-specific circulating microRNAs in HCV-induced hepatocellular Carcinoma in Egyptian patients

OBJECTIVES

Due to the absence of reliable and accurate biomarkers for the early detection of liver malignancy, circulating microRNAs have recently emerged as great candidates for prompt cancer identification. Therefore, the aim of this study was to investigate the potential of liver-specific circulating microRNAs as an accurate non-invasive diagnostic tool for early diagnosis of hepatitis C virus (HCV)-induced hepatocellular carcinoma (HCC).

METHODOLOGY

A total of 165 patients were enrolled in this study and categorized into four main groups: 42 chronic hepatitis C (CHC) without cirrhosis, 45 CHC with cirrhosis (LC), 38 HCC with HCV patients, and 40 healthy controls. The expression profiles of seven miRNAs (miR-16, miR-34a, miR-125a, miR-139, miR-145, miR-199a, and miR-221) were analyzed using real-time PCR.

RESULTS

Serum levels of miRNA-125a, miRNA-139, miRNA-145, and miRNA199a were significantly lower (p < 0.01) in HCC than in both CHC and LC groups. On the other hand, no significant difference was shown in the expression of miR-16, miR-34a, and miR-221 between the CHC, LC, and HCC groups. MiR-16, miR-34a, and miR-221 were significantly elevated in the HCC group compared to the control group. MiR-34a showed the highest specificity and sensitivity.

CONCLUSIONS

The results indicated that the measurement of serum levels of miR-125a, miR-139, miR-145, and miR-199a can help to differentiate HCC from CHC and LC. Also, miR-16, miR-34a, and miR-221 serum levels would have a prognostic value. MiR-34a had the highest specificity and sensitivity, indicating that it might serve as a novel and potential non-invasive biomarker for HCV-induced HCC.

MicroRNA-300 inhibited glioblastoma progression through ROCK1

Glioblastoma is a common type of brain aggressive tumors and has a poor prognosis. MicroRNAs (miRNAs) are a class of small, endogenous and non-coding RNAs that play crucial roles in cell proliferation, survival and invasion. Deregulated expression of miR-300 has been studied in a lot of cancers. However, the role of miR-300 in glioblastoma is still unknown. In this study, we demonstrated that miR-300 expression was downregulated in glioblastoma tissues compared with the normal tissues. Lower expression level of miR-300 was observed in thirty cases (75 %, 30/40) of glioblastoma samples compared with the normal samples. Moreover, the overall survival of glioblastoma patients with lower miR-300 expression level was shorter than those with higher miR-300 expression level. In addition, miR-300 expression was also downregulated in glioblastoma cell lines. Overexpression of miR-300 inhibited cell proliferation, cell cycle and invasion in glioblastoma cell line U87 and U251. Moreover, we identified ROCK1 as a direct target of miR-300 in U87 and U251 cells. Overexpression of ROCK1 partially rescued the miR-300-mediated cell growth. ROCK1 expression levels in glioblastoma tissues were higher than that in normal tissues. ROCK1 expression levels were higher in thirty-one cases of glioblastoma samples than their normal samples. Furthermore, the expression level ROCK1 was inversely correlated with the expression level of miR-300. Importantly, overexpression of miR-300 suppressed glioblastoma progression in an established xenograft model. In conclusion, we revealed that miR-300 might act as a tumor suppressor gene through inhibiting ROCK1 in glioblastoma.

The expression and function of miR-424 in infantile skin hemangioma and its mechanism

Infantile hemangioma is the most common benign tumor in infants. Many studies have confirmed that basic fibroblast growth factor (bFGF) and its key receptor FGFR1 are highly expressed in hemangioma. Moreover, several miRNAs can regulate angiogenesis. In this regard, miR-424 often plays a role as tumor suppressor gene. This study was designed to investigate the mechanism of miR-424 in infantile skin hemangioma. Our results showed low expression of miR-424 in infantile skin hemangioma tissues, and that miR-424 overexpression downregulated FGFR1 expression in hemangioma-derived endothelial cells, while miR-424 inhibition upregulated FGFR1 expression. Luciferase reporter analysis confirmed that FGFR1 was a target gene of miR-424. CCK-8, flow cytometry, transwell migration and tube formation assays demonstrated that miR-424 overexpression inhibited cell proliferation, migration and tube formation, at least in part by blocking the bFGF/FGFR1 pathway. In contrast, miR-424 inhibition significantly enhanced these functions. Furthermore, miR-424 overexpression significantly inhibited ERK1/2 phosphorylation, whereas miR-424 inhibition enhanced ERK1/2 phosphorylation. In conclusion, miR-424 could suppress the bFGF/FGFR1 pathway, thereby inhibit ERK1/2 phosphorylation, and thus inhibit cell proliferation, migration and tube formation capabilities and the development of infantile skin hemangioma.

Homeodomain-interacting protein kinase 2 (HIPK2): a promising target for anti-cancer therapies

The HIPK2 (serine/threonine homeodomain-interacting protein kinase 2) is a "caretaker" gene, its inactivation increases tumorigenicity while its activation inhibits tumor growth. This report reviews the anti-tumorigenic mechanisms of HIPK2, which include promotion of apoptosis, inhibition of angiogenesis in hypoxia, prevention of tumor invasion/metastasis and attenuation of multidrug resistance in cancer. Additionally, we summarize conditions or factors that may increase HIPK2 activity.

Circular RNA_LARP4 inhibits cell proliferation and invasion of gastric cancer by sponging miR-424-5p and regulating LATS1 expression

BACKGROUND

Non-coding RNAs (ncRNAs) have been shown to regulate gene expression involved in tumor progression of multiple malignancies. Our previous studies indicated that large tumor suppressor kinase 1 (LATS1), a core part of Hippo signaling pathway, functions as a tumor suppressor in gastric cancer (GC). But, the underlying molecular mechanisms by which ncRNAs modulate LATS1 expression in GC remain undetermined.

METHODS

The correlation of LATS1 and has-miR-424-5p (miR-424) expression with clinicopathological characteristics and prognosis of GC patients was analyzed by TCGA RNA-sequencing data. A novel circular RNA_LARP4 (circLARP4) was identified to sponge miR-424 by circRNA expression profile and bioinformatic analysis. The binding site between miR-424 and LATS1 or circLARP4 was verified using dual luciferase assay and RNA immunoprecipitation (RIP) assay. The expression and localization of circLARP4 in GC tissues were investigated by fluorescence in situ hybridization (FISH). MTT, colony formation, Transwell and EdU assays were performed to assess the effects of miR-424 or circLARP4 on cell proliferation and invasion.

RESULTS

Increased miR-424 expression or decreased LATS1 expression was associated with pathological stage and unfavorable prognosis of GC patients. Ectopic expression of miR-424 promoted proliferation and invasion of GC cells by targeting LATS1 gene. Furthermore, circLARP4 was mainly localized in the cytoplasm and inhibited biological behaviors of GC cells by sponging miR-424. The expression of circLARP4 was downregulated in GC tissues and represented an independent prognostic factor for overall survival of GC patients.

CONCLUSION

circLARP4 may act as a novel tumor suppressive factor and a potential biomarker in GC.

MiR-424 functions as a tumor suppressor in glioma cells and is down-regulated by DNA methylation

Glioma is one of the most lethal malignancies, and increasing reports revealed that microRNAs (miRNAs), a class of small non-coding RNAs, play a critical role in the development and pathology of human gliomas. MiR-424 has been found to be dysregulated in many different types of human cancers. However, the clinical significance and function of miR-424 in glioma remains unclear. Here, based on RTq-PCR analysis in 148 clinical specimens, we found miR-424 expression was significantly decreased in glioma tumor tissues than in adjacent non-neoplastic brain tissues, and decreased miR-424 expression was associated with glioma KPS (P = 0.009) and high grades (P = 0.029). In vitro cellular function assays further revealed that miR-424 inhibited cell invasion and migration, and promoted cell apoptosis. In addition, based on DNA methylation analysis on clinical specimens and cell lines, we found miR-424 promoter CpG island was frequently methylated and correlated with glioma high grades (P = 0.035) and IDH mutation status (P = 0.042). Moreover, the promoter CpG island was demethylated by 5-aza-2'-deoxycytidine treatment in a time-dependent manner and the expression levels of miR-424 were gradually induced and increased. Taken together, our data suggest that the promoter region CpG island methylation is associated with tumor suppressive miR-424 silencing and the pathology of human gliomas.

A genome-wide microRNA profiling indicates miR-424-5p and miR-503-5p as regulators of ALK expression in neuroblastoma

The discovery of missense mutations of ALK gene identified this receptor tyrosine kinase as a therapeutic target in neuroblastoma (NB). Moreover, a high level of ALK protein has been associated with metastatic NB cases and with a worse prognosis, suggesting that also ALK overexpression is involved in NB tumorigenesis. Since miRNAs play key roles in the regulation of gene expression we aimed at identifying those miRNAs that can regulate ALK in NB. We therefore analyzed the genome-wide expression profile of miRNAs in two sample sets of 16 NB cell lines and 22 NB samples by using miRNA microarrays. Both sample sets were then divided into two subgroups showing high (ALK+) or low/absent (ALK-) expression of ALK. Results showed a down-regulation of 30 and 23 miRNAs (p-value <0.05) in the ALK+ group in NB cell lines and samples, respectively. Validation analysis indicated that miR-424-5p and miR-503-5p, belonging to the same cluster, were differentially expressed in both NB cell lines and tumor samples. Although only miR-424-5p showed a direct binding to ALK 3′-UTR, both miRNAs led to a remarkable decreasing of ALK protein as well as to the inhibition of cell viability in ALK+ NB cell lines. In conclusion, our data indicate that both miR-424-5p and miR-503-5p are involved in regulating ALK expression in NB, either by directly targeting ALK receptor or indirectly, and may thus serve as potential therapeutic tools in ALK dependent NBs.

FOXO1-suppressed miR-424 regulates the proliferation and osteogenic differentiation of MSCs by targeting FGF2 under oxidative stress

Recently, microRNAs (miRNAs) have been identified as key regulators of the proliferation and differentiation of mesenchymal stem cells (MSCs). Our previous in vivo study and other in vitro studies using miRNA microarrays suggest that miR-424 is involved in the regulation of bone formation. However, the role and mechanism of miR-424 in bone formation still remain unknown. Here, we identified that the downregulation of miR-424 mediates bone formation under oxidative stress, and we explored its underlying mechanism. Our results showed that miR-424 was significantly downregulated in an anterior lumbar interbody fusion model of pigs and in a cell model of oxidative stress induced by H₂O₂. The overexpression of miR-424 inhibited proliferation and osteogenic differentiation shown by a decrease in alkaline phosphatase (ALP) activity, mineralization and osteogenic markers, including RUNX2 and ALP, whereas the knockdown of miR-424 led to the opposite results. Moreover, miR-424 exerts its effects by targeting FGF2. Furthermore, we found that FOXO1 suppressed miR-424 expression and bound to its promoter region. FOXO1 enhanced proliferation and osteogenic differentiation in part through the miR-424/FGF2 pathway. These results indicated that FOXO1-suppressed miR-424 regulates both the proliferation and osteogenic differentiation of MSCs via targeting FGF2, suggesting that miR-424 might be a potential novel therapeutic strategy for promoting bone formation.

MicroRNA-665 suppressed the invasion and metastasis of osteosarcoma by directly inhibiting RAB23

MicroRNAs (miRNAs) are small, short and noncoding RNAs that regulate gene expression posttranscriptionally. Increasing evidences have demonstrated that deregulated expression of miRNAs is found in osteosarcoma. In this study, we demonstrated that miR-665 was downregulated in osteosarcoma tissues compared to non-tumorous tissues. The overall survival (OS) of osteosarcoma patients with low miR-665 expression was lower than that of these patients with high miR-665 expression. Ectopic expression of miR-665 suppressed the osteosarcoma cell proliferation, EMT and invasion. We identified Rab23 as a direct target gene of miR-665. Rab23 was downregulated in osteosarcoma tissues and cell lines. The expression of miR-665 was inversely associated with the expression of Rab23 in the osteosarcoma tissues. These results suggested that miR-665 acted as a tumor suppressor gene in the development of osteosarcoma.

Loss of MiR-424-3p, not miR-424-5p, confers chemoresistance through targeting YAP1 in non-small cell lung cancer

MiR-424 has been discovered to be involved in the chemoresistance of lung cancer. However, the underlying mechanism by which miR-424 played role in chemoresistance has been unknown. Here, in our study, to investigate the role of miR-424 in non-small cell lung cancer (NSCLC), we have detected the expression of miR-424-3p and -5p in NSCLC tissues and paired normal control. Moreover, to explore the role of miR-424-3p in NSCLC cells, miR-424-3p and -5p were both re-expressed and knocked down using transient transfection with their respective mimics and inhibitors. Cell viability, migration, and invasion were evaluated using MTT, wound-healing and Transwell assays, respectively. It was found that down-regulation of miR-424-3p was pronouncedly associated with NSCLC progression and overall prognosis; and that both miR-424-3p and -5p were markedly capable of preventing the proliferation, migration, and invasion in NSCLC cells. Additionally, it is miR-424-3p but not miR-424-5p that enhances the chemo-sensitivity of NSCLC cells through targeting YAP1. Mechanistically, YAP1 was identified as down-stream target of miR-424-3p. Together, it was for the first time in our study found that it is loss of miR-424-3p not miR-424-5p that enables chemoresistance through targeting YAP1 in NSCLC, supporting that miR-424-3p could be used as therapeutic target in the curing of NSCLC with chemoresistance. © 2016 Wiley Periodicals, Inc.

MicroRNA-424 inhibits Akt3/E2F3 axis and tumor growth in hepatocellular carcinoma

By comparing the expression profiles of miRNAs in different subtypes of HCC, we identified miR-424 as a HCC related miRNA. We found that the expression of miR-424 was significantly decreased in HCC tissues and six liver cancer cell lines. Significantly, its expression levels were correlated with tumor size, multiple nodules, vein invasion, TNM stage and overall survival of HCC. We showed that up-regulated miR-424 suppressed HCC cell proliferation in vivo and in vitro. Multi-pathway reporter arrays suggested that miR-424 suppressed the pRb-E2F pathway. Consistently, Akt3 and E2F3 were identified as the targets of miR-424 as evidenced by that ectopic miR-424 expression suppressed Akt3 and E2F3 expressions. Silencing Akt3 and E2F3 by siRNA pheno-copied the effect of ectopic miR-424 on HCC growth. Whereas, overexpression of Akt3 and E2F3 attenuated the effect of miR-424 on HCC growth. Together, our data demonstrated a tumor suppressor role for miR-424 in HCC development and progression with therapeutic implications. The strong correlation of miR-424 expression with HCC patient survival suggests that miR-424 could be a valuable biomarker for HCC prognosis.