MicroRNA-381 represses ID1 and is deregulated in lung adenocarcinoma

Identification of ID1 and miR-150 interaction and effects on proliferation and apoptosis in ovine granulosa cells

Granulosa cells (GCs) proliferation and apoptosis play a significantly role in follicular development and atresia. ID1 and miR-150 are involved in cell apoptosis and follicular atresia, but the interaction and function of ID1 and miR-150 in GCs are unclear. This study focuses on ID1 and miR-150 in terms of the interaction and effects on proliferation and apoptosis in ovine granulosa cells. Our findings revealed that ID1 decreased the promoter activity and expression level of oar-miR-150. However, the expression of ID1 was downregulated by miR-150, and ID1 was identified as a target gene of oar-miR-150. miR-150 mimic inhibited proliferation and upregulated apoptosis rate in ovine GCs, while the results of miR-150 inhibitor were opposite. Overexpression of ID1 significantly inhibited ovine GCs proliferation and cell cycle-related genes (CDK1, CDK2, CDK4, CCND2, CDC20, and PCNA) expression, whereas knockdown of ID1 promoted cell proliferation and those genes expression. Overexpression of ID1 significantly downregulated mitochondrial membrane potential and Bcl-2 expression in ovine GCs, and upregulated the expression of pro-apoptosis genes Bax, Caspase-3, and Caspase-9, whereas the results of ID1 knockdown were reversed. Collectively, these findings indicate the interaction and the vital role of ID1 and miR-150 on proliferation and apoptosis in ovine granulosa cells, which may suggest a novel target for ovine follicular development and atresia.

The non-cell-autonomous function of ID1 promotes AML progression via ANGPTL7 from the microenvironment

The bone marrow microenvironment (BMM) can regulate leukemia stem cells (LSCs) via secreted factors. Increasing evidence suggests that dissecting the mechanisms by which the BMM maintains LSCs may lead to the development of effective therapies for the eradication of leukemia. Inhibitor of DNA binding 1 (ID1), a key transcriptional regulator in LSCs, previously identified by us, controls cytokine production in the BMM, but the role of ID1 in acute myeloid leukemia (AML) BMM remains obscure. Here, we report that ID1 is highly expressed in the BMM of patients with AML, especially in BM mesenchymal stem cells, and that the high expression of ID1 in the AML BMM is induced by BMP6, secreted from AML cells. Knocking out ID1 in mesenchymal cells significantly suppresses the proliferation of cocultured AML cells. Loss of Id1 in the BMM results in impaired AML progression in AML mouse models. Mechanistically, we found that Id1 deficiency significantly reduces SP1 protein levels in mesenchymal cells cocultured with AML cells. Using ID1-interactome analysis, we found that ID1 interacts with RNF4, an E3 ubiquitin ligase, and causes a decrease in SP1 ubiquitination. Disrupting the ID1-RNF4 interaction via truncation in mesenchymal cells significantly reduces SP1 protein levels and delays AML cell proliferation. We identify that the target of Sp1, Angptl7, is the primary differentially expression protein factor in Id1-deficient BM supernatant fluid to regulate AML progression in mice. Our study highlights the critical role of ID1 in the AML BMM and aids the development of therapeutic strategies for AML.

MiRNAs in Lung Adenocarcinoma: Role, Diagnosis, Prognosis, and Therapy

Lung cancer has emerged as a significant public health challenge and remains the leading cause of cancer-related mortality worldwide. Among various types of lung malignancies, lung adenocarcinoma (LUAD) stands as the most prevalent form. MicroRNAs (miRNAs) play a crucial role in gene regulation, and their involvement in cancer has been extensively explored. While several reviews have been published on miRNAs and lung cancer, there remains a gap in the review regarding miRNAs specifically in LUAD. In this review, we not only highlight the potential diagnostic, prognostic, and therapeutic implications of miRNAs in LUAD, but also present an inclusive overview of the extensive research conducted on miRNAs in this particular context.

In silico analysis reveals hypoxia-induced miR-210-3p specifically targets SARS-CoV-2 RNA

Human coronaviruses (HCoVs) until the emergence of SARS in 2003 were associated with mild cold and upper respiratory tract infections. The ongoing pandemic caused by SARS-CoV-2 has enhanced the potential for infection and transmission as compared to other known members of this family. MicroRNAs (miRNA) are 21-25 nucleotides long non-coding RNA that bind to 3' UTR of genes and regulate almost every aspect of cellular function. Several human miRNAs have been known to target viral genomes, mostly to downregulate their expression and sometimes to upregulate also. In some cases, host miRNAs could be sequestered by the viral genome to create a condition for favourable virus existence. The ongoing SARS CoV-2 pandemic is unique based on its transmissibility and severity and we hypothesised that there could be a unique mechanism for its pathogenesis. In this study, we exploited in silico approach to identify human respiratory system-specific miRNAs targeting the viral genome of three highly pathogenic HCoVs (SARS-CoV-2 Wuhan strain, SARS-CoV, and MERS-CoV) and three low pathogenic HCoVs (OC43, NL63, and HKU1). We identified ten common microRNAs that target all HCoVs studied here. In addition, we identified unique miRNAs which targeted specifically one particular HCoV. miR-210-3p was the single unique lung-specific miRNA, which was found to target the NSP3, NSP4, and NSP13 genes of SARS-CoV-2. Further miR-210-NSP3, miR-210-NSP4, and miR-210-NSP13 SARS-CoV-2 duplexes were docked with the hAGO2 protein (PDB ID 4F3T) which showed Z-score values of -1.9, -1.7, and -1.6, respectively. The role of miR-210-3p as master hypoxia regulator and inflammation regulation may be important for SARS-CoV-2 pathogenesis. Overall, this analysis advocates that miR-210-3p be investigated experimentally in SARS-CoV-2 infection.Communicated by Ramaswamy H. Sarma.

Tumor-suppressing effects of miR-381-3p in pediatric acute myeloid leukemia via ROCK1 downregulation

MicroRNA (miR)-381-3p is the newly discovered tumor-associated miRNA, which is frequently associated with diverse human malignancies; but, it is still unknown about its effect on acute myeloid leukemia (AML) in children. This work focused on exploring miR-381-3p's effect on childhood AML and identifying the possible mechanisms facilitating new treatment development. Using qRT-PCR analysis, miR-381-3p expression remarkably reduced in pediatric AML patients and AML cell lines (HL-60 and U937). Following transfection of miR-381-3p mimic or inhibitor into HL-60 and U937 cells, we conducted MTT assay to evaluate cell proliferation, flow cytometry (FCM) to measured cell apoptosis and cell cycle, whereas Transwell assays to detect cell invasion and migration. Our results demonstrated that miR-381-3p overexpression remarkably repressed cell growth, invasion and migration; additionally, miR-381-3p overexpression resulted in arrest of cell cycle and enhanced cell apoptosis. In contrast, miR-381-3p knockdown led to an opposite effect. Moreover, we predicted miR-381's target gene and validated it by luciferase reporter assay and TargetScan, separately. We identified miR-381-3p's binding site in ROCK1 3'-UTR. As revealed by Western-blot (WB) assay, miR-381-3p overexpression notably suppressed ROCK1 level. Moreover, restoring ROCK1 expression abolished miR-381-3p's inhibition on cell proliferation, invasion and migration. Data in this work indicated the role of miR-381-3p as the tumor suppressor within pediatric AML by targeting ROCK1. Therefore, miR-381-3p might serve as a potential therapeutic target for the treatment of pediatric AML.

miR-381-3p Cooperated With Hes1 to Regulate the Proliferation and Differentiation of Retinal Progenitor Cells

Retinal progenitor cells (RPCs) transplantation has become a promising therapy for retinal degeneration, which is a major kind of ocular diseases causing blindness. Since RPCs have limited proliferation and differentiation abilities toward retinal neurons, it is urgent to resolve these problems. MicroRNAs have been reported to have vital effects on stem cell fate. In our study, the data showed that overexpression of miR-381-3p repressed Hes1 expression, which promoted RPCs differentiation, especially toward neuronal cells, and inhibited RPCs proliferation. Knockdown of endogenous miR-381-3p increased Hes1 expression to inhibit RPCs differentiation and promote proliferation. In addition, a luciferase assay demonstrated that miR-381-3p directly targeted the Hes1 3’ untranslated region (UTR). Taken together, our study demonstrated that miR-381-3p regulated RPCs proliferation and differentiation by targeting Hes1, which provides an experimental basis of RPCs transplantation therapy for retinal degeneration.

MicroRNA-381 in human cancer: Its involvement in tumour biology and clinical applications potential

MicroRNAs (miRNAs) are small non‐coding RNAs that regulate gene expression at the post‐transcriptional level. MiRNAs are involved in the development and progression of a wide range of cancers. Among such cancer‐associated miRNAs, miR‐381 has been a major focus of research. The expression pattern and role of miR‐381 vary among different cancer types. MiR‐381 modulates various cellular behaviours in cancer, including proliferation, apoptosis, cell cycle progression, migration and invasion. MiR‐381 is also involved in angiogenesis and lymphangiogenesis, as well as in the resistance to chemotherapy and radiotherapy. MiR‐381 itself is regulated by several factors, such as long noncoding RNAs, circular RNAs and cytokines. Aberrant expression of miR‐381 in blood samples indicates that it can be used as a diagnostic marker in cancer. Tissue miR‐381 expression may serve as a prognostic factor for the clinicopathological characteristics of cancers and survival of patients. Metformin and icaritin regulate miR‐381 expression and present anticancer properties. This review comprehensively summarizes the effect of miR‐381 on tumour biological behaviours, as well as the clinical application potential of miR‐381 for the treatment of cancer.

miR-381-3p suppresses breast cancer progression by inhibition of epithelial-mesenchymal transition

Background

Accumulating evidence indicates that miRNAs are involved in multiple cellular functions and participate in various cancer development and progression, including breast cancer.

Methods

We aimed to investigate the role of miR-381-3p in breast cancer. The expression level of miR-381-3p and EMT transcription factors was examined by quantitative real-time PCR (qRT-PCR). The effects of miR-381-3p on breast cancer proliferation and invasion were determined by Cell Counting Kit-8 (CCK-8), colony formation, and transwell assays. The regulation of miR-381-3p on its targets was determined by dual-luciferase analysis, qRT-PCR, and western blot.

Results

We found that the expression of miR-381-3p was significantly decreased in breast cancer tissues and cell lines. Overexpression of miR-381-3p inhibited breast cancer proliferation and invasion, whereas knockdown of miR-381-3p promoted cell proliferation and invasion in MDA-MB-231 and SKBR3 cells. Mechanistically, overexpression of miR-381-3p inhibited breast cancer epithelial–mesenchymal transition (EMT). Both Sox4 and Twist1 were confirmed as targets of miR-381-3p. Moreover, transforming growth factor-β (TGF-β) could reverse the effects of miR-381-3p on breast cancer progression.

Conclusions

Our observation suggests that miR-381-3p inhibits breast cancer progression and EMT by regulating the TGF-β signaling via targeting Sox4 and Twist1.

MicroRNAs and Long Non-Coding RNAs as Potential Candidates to Target Specific Motifs of SARS-CoV-2

The respiratory system is one of the most affected targets of SARS-CoV-2. Various therapies have been utilized to counter viral-induced inflammatory complications, with diverse success rates. Pending the distribution of an effective vaccine to the whole population and the achievement of "herd immunity", the discovery of novel specific therapies is to be considered a very important objective. Here, we report a computational study demonstrating the existence of target motifs in the SARS-CoV-2 genome suitable for specific binding with endogenous human micro and long non-coding RNAs (miRNAs and lncRNAs, respectively), which can, therefore, be considered a conceptual background for the development of miRNA-based drugs against COVID-19. The SARS-CoV-2 genome contains three motifs in the 5'UTR leader sequence recognized by selective nucleotides within the seed sequence of specific human miRNAs. The seed of 57 microRNAs contained a "GGG" motif that promoted leader sequence-recognition, primarily through offset-6mer sites able to promote microRNAs noncanonical binding to viral RNA. Similarly, lncRNA H19 binds to the 5'UTR of the viral genome and, more specifically, to the transcript of the viral gene Spike, which has a pivotal role in viral infection. Notably, some of the non-coding RNAs identified in our study as candidates for inhibiting SARS-CoV-2 gene expression have already been proposed against diverse viral infections, pulmonary arterial hypertension, and related diseases.

MicroRNA-381-A Key Transcriptional Regulator: Its Biological Function and Clinical Application Prospects in Cancer

MicroRNAs (miRNAs) are small non-coding RNA molecules that function by regulating messenger RNAs. Recent studies have shown that miRNAs play important roles in multiple processes of cancer development. MiR-381 is one of the most important miRNAs in cancer progression. MiR-381 is downregulated in some cancers and upregulated in other cancers, including glioma, epithelial sarcoma, and osteosarcoma. MiR-381 regulates epithelial-mesenchymal transition (EMT), chemotherapeutic resistance, radioresistance, and immune responses. Thus, miR-381 participates in tumor initiation, progression, and metastasis. Moreover, miR-381 functions in various oncogenic pathways, including the Wnt/β-catenin, AKT, and p53 pathways. Clinical studies have shown that miR-381 could be considered a biomarker or a novel prognostic factor. Here, we summarize the present studies on the role of miR-381 in cancer development, including its biogenesis and various affected signaling pathways, and its clinical application prospects. MiR-381 expression is associated with tumor stage and survival time, making miR-381 a novel prognostic factor.

MicroRNA‑381 regulates the growth of gastric cancer cell by targeting TWIST1

Gastric cancer (GC) has one of the highest mortality rates among all types of cancer in the world. At present, an efficient treatment for GC remains elusive. Studies have demonstrated that microRNAs (miRs) are abnormally expressed in cancer, and that these serve important roles in the development and metastasis of various human tumors, including GC. It has been suggested that regulation of miRs may bring about new developments in GC therapy. miR‑381 has been reported to be downregulated in human cancer, and it regulates cancer cell growth in numerous types of cancer. The present study reports that miR‑381 was downregulated in GC cells, and upregulation of miR‑381 may inhibit GC cell growth, which may be attributed to the inhibition of cell proliferation and the promotion of apoptosis. Furthermore, Twist‑related protein 1 (TWIST1) was predicted and confirmed to be a direct target of miR‑381 by dual‑luciferase assay in GC. Upregulation of miR‑381 caused a decrease in the expression of TWIST1 at the mRNA and protein levels in GC cells. Taken together, the present study demonstrated that miR‑381 is downregulated in GC cells, and that miR‑381 may inhibit GC cell growth. Therefore, miR‑381 may serve as a novel target for the clinical treatment of GC in the future.

Serum microRNA-381: A Potential Marker for Early Diagnosis of Gastric Cancer

PURPOSE

The purpose of this study was to explore the potential early diagnostic value of serum microRNA-381(miRNA-381) in patients with gastric cancer (GC).

MATERIALS AND METHODS

Patients with advanced gastric cancer (AGC) and early gastric cancer (EGC), as well as healthy individuals, were enrolled in this study. Expression of miRNA-381 in serum was detected using real-time quantitative PCR. Electrochemiluminescence analysis was used to investigate the expression of classic tumor markers, including carbohydrate antigen (CA) 199, CA724, and carcinoembryonic antigen. Finally, receiver operating characteristic curve and Kaplan-Meier analysis were used to determine the value of miRNA-381 in clinical diagnosis of GC.

RESULTS

miRNA-381 was differentially expressed among the study groups. AUC analysis showed that the sensitivity and specificity of serum miRNA-381 in the diagnosis of GC were superior to those of other tumor markers. Furthermore, low levels of miRNA-381 expression were positively correlated with lymph node metastasis and AGC. Finally, Kaplan-Meier survival analysis showed that down-regulation of miRNA-381 was associated with lymph node metastasis and the development of GC.

CONCLUSION

miRNA381, which was down-regulated in GC, might be a novel early diagnosis marker for patients with GC.

Inhibition of MicroRNA-381 Promotes Tumor Cell Growth and Chemoresistance in Clear-Cell Renal Cell Carcinoma

Background

MicroRNA-381 (miR-381) is proven to be involved in many human tumors. Bioinformatics prediction suggests that miR-381 is decreased in renal cell carcinoma. However, its biological functions in clear-cell renal cell carcinoma (ccRCC) remain largely unknown. The present research aimed to evaluate miR-381 expression in renal cancer tissues and its effects on cell proliferation, growth, migration, and chemoresistance.

Material/Methods

Sixty pairs of ccRCC and the adjacent non-tumor specimens were collected during routine therapeutic surgery. Quantitative real-time PCR (qRT-PCR) assay was employed to examine miR-381 expression in the ccRCC tissues and the associated adjacent tissues (the normal tissues adjacent to tumor tissues). Cell transfection assay and Thiazolyl Blue Tetrazolium Bromide (MTT) assay were utilized to observe effects of miR-381 on the cell proliferation, growth, invasion, and chemoresistance in the Caki-1 cell line and 786-O cell line. Flow cytometry was used to assess cell apoptosis. Caki-1 cell and 786-O cell Xenograft BALB/c mouse models were established.

Results

miR-381 expression was downregulated in ccRCC tissues in vivo and in cell lines in vitro. Downregulation of miR-381 promoted growth of cells and restrained the ccRCC cell apoptosis. Increased miR-381 combined with Ci and Pa suppressed the proliferation and enhanced the anti-tumor effects of Ci and Pa at tolerated concentrations in vitro. miR-381 inhibition promoted chemoresistance in vitro.

Conclusions

miR-381 levels were significantly downregulated in renal cancer tissues and miR-381 inhibition promoted tumor cell growth, migration, and chemoresistance.

MicroRNA-381 suppresses proliferation and invasion of prostate cancer cells through downregulation of the androgen receptor

Prostate cancer (PCa) is the most frequently diagnosed malignancy in men and its incidence has increased rapidly worldwide. Notably, the molecular mechanisms underlying prostate tumorigenesis have not been fully identified. The levels of microRNA (miR)-381 have been explored in numerous types of malignancy; however, the expression levels and biological function of miR-381 in PCa remain largely unknown. In the present study, reverse-transcription polymerase chain reaction was used to detect the expression levels of miR-381 in PCa cells and normal prostate epithelial cells. Subsequently, miR-381 antisense oligonucleotides and mimics were transfected into LNCaP PCa cells. Bioinformatics analysis was performed to identify the potential target genes of miR-381. Protein expression analysis, dual-luciferase reporter assay and a rescue assay were used to confirm the target of miR-381. The data suggested that the expression levels of miR-381 were significantly decreased in PCa cells compared with in normal prostatic epithelial cells. Furthermore, transfection of LNCaP cells with miR-381 mimics suppressed their proliferation, migration and invasion. In addition, bioinformatics analysis suggested that the androgen receptor (AR) was a target gene of miR-381. miR-381 suppressed the expression levels of AR by directly binding to its 3'-untranslated region. Furthermore, transfection with an AR plasmid partially attenuated miR-381-induced inhibition of cell proliferation, migration and invasion. The results of the present study suggested that miR-381 may act as a tumor suppressor in PCa by directly targeting the AR.

Relationship between single nucleotide polymorphisms in the 3'UTR of amyloid precursor protein and risk of Alzheimer's disease and its mechanism

Background and objective: Deregulation of the expression of amyloid precursor protein (APP) can lead to the development of Alzheimer's disease (AD). Recent studies have shown that many single nucleotide polymorphisms (SNPs) in the 3' untranslated region (UTR) of APP are associated with the development of AD. Since microRNAs (miRNAs) are involved in the regulation of APP expression, we believe that the APP 3'UTR polymorphism may affect the regulation of APP expression in miRNAs. Results: The levels of miR-101-3p, miR-153-3p, miR-144-3p, miR-381-3p, and miR-383-5p in plasma of patients with AD were significantly lower than those in the control group. The APP-534G/A site A allele was a protective factor for AD risk (adjusted odds ratio (OR) = 0.700, 95% confidence interval (95% CI): 0.573-0.840, P<0.001). The APP-369C/G site variation was not associated with AD risk. The APP-118C/A site A allele was a protective factor for AD (adjusted OR = 0.762, 95% CI: 0.639-0.897, P=0.001). The APP-534G/A site mutation affects the regulation of APP protein expression by miR-101-3p, miR-144-3p, miR-153-3p, and miR-381-3p, and the mutation of the APP-118C/A site affects miR-101-3p, miR-144-3p, miR-153-3p, and miR-383-5p regulation of APP expression. Conclusion: APP 3'UTR polymorphisms can affect the regulation of APP expression by miRNAs and thus affect the occurrence of AD.

Wnt pathway targeting reduces triple-negative breast cancer aggressiveness through miRNA regulation in vitro and in vivo

Triple-negative breast cancer, devoid of estrogen (ER), progesterone (PR), and human epidermal growth factor receptor 2 (HER-2) expression, is deprived of commonly used targeted therapies. MicroRNAs (miRNAs) are undergoing a revolution in terms of potentially diagnostic or therapeutic elements. Combining computational approaches, we enriched miRNA binding motifs of Wnt pathway-associated upregulated genes. Our in-depth bioinformatics, in vitro and in vivo analyses indicated that miR-381 targets main genes of the Wnt signaling pathway including CTNNB1, RhoA, ROCK1, and c-MYC genes. The expression level of miR-381 and target genes was assessed by quantitative real-time polymerase chain reaction (RT-qPCR) in MCF-7, MDA-MB-231, and MCF-10A as well as 20 breast cancer samples and normal tissues. Luciferase reporter assay was performed. Lentiviral particles containing miR-381 were used to evaluate the effect of miR-381 restoration on cell proliferation, migration, and invasion of the invasive triple-negative MDA-MB-231 cell line and also in a mouse model of breast cancer. The expression of miR-381 was lower than that of normal cells, especially in TNBC cell line and breast tissues. Luciferase assay results confirmed that miR-381 targets all the predicted 3'-untranslated regions (3'-UTRs). Upon miR-381 overexpression, the expression of target genes declined, and the migration and invasion potential of miR-381-receiving MDA-MB-231 cells decreased. In a mouse model of triple-negative breast cancer, miR-381 re-expression inhibited the invasion of cancer cells to lung and liver and prolonged the survival time of cancer cell-bearing mice. Therefore, miR-381 is a regulator of Wnt signaling and its re-expression provides a potentially effective strategy for inhibition of TNBC.

Prognostic value of microRNAs in lung cancer: A systematic review and meta-analysis

Lung cancer is one of the leading causes of cancer-associated mortality throughout the world. The prognosis of the disease depends on many factors including the stage and type of cancer. Many studies have identified various microRNAs (miRNAs) that affect the prognosis of lung cancer. In order to systemically analyze the available clinical data, the present study performed a meta-analysis to examine all evidence on the potential role of miRNAs as novel predictors of survival in lung cancer. Literature published in English prior to February 1st, 2018 was searched through PubMed to review all of the associations between individual miRNAs and groups of miRNAs with the prognosis of lung cancer. Data was extracted using standard forms and pooled odds ratios with 95% confidence intervals (CIs) were calculated. A total of 15 eligible studies were included in the meta-analysis. These represented 1,753 lung cancer patients and 20 miRNAs. A total of 8 downregulated miRNAs were associated with poorer overall survival (OS) [hazard ratio (HR)=0.59, 95% CI: 0.47–0.75, P<1×10⁻⁴], while 10 upregulated miRNAs were associated with poorer OS (HR=1.76, 95% CI: 1.31–2.35, P<1×10⁻⁴). Additionally, low miRNA expression was associated with lymph node metastasis [LNM; relative risk (RR)=0.53, 95% CI: 0.46–0.61, P<1×10⁻⁴]. The expression of miRNAs was not associated with lung cancer stage (RR=1.07, 95% CI: 0.94–1.22, P=0.23). Expression levels of different miRNAs were associated with the OS and LNM of patients with lung cancer. These miRNAs may be applied as potential prognostic markers in lung cancer.

Stabilization of miRNAs in esophageal cancer contributes to radioresistance and limits efficacy of therapy

The five-year survival rate of esophageal cancer patients is less than 20%. This may be due to increased resistance (acquired or intrinsic) of tumor cells to chemo/radiotherapies, often caused by aberrant cell cycle, deregulated apoptosis, increases in growth factor signaling pathways, and/or changes in the proteome network. In addition, deregulation in non-coding RNA-mediated signaling pathways may contribute to resistance to therapies. At the molecular level, these resistance factors have now been linked to various microRNA (miRNAs), which have recently been shown to control cell development, differentiation and neoplasia. The increased stability and dysregulated expression of miRNAs have been associated with increased resistance to various therapies in several cancers, including esophageal cancer. Therefore, miRNAs represent the next generation of molecules with tremendous potential as biomarkers and therapeutic targets. However, detailed studies on miRNA-based therapeutic interventions are still in their infancy. Hence, in this review, we have summarized the current status of microRNAs in dictating the resistance/sensitivity of tumor cells to chemotherapy and radiotherapy. In addition, we have discussed various strategies to increase radiosensitivity, including targeted therapy, and the use of miRNAs as radiosensitive/radioresistance biomarkers for esophageal cancer in the clinical setting.

MiR-381 negatively regulates cardiomyocyte survival by suppressing Notch signaling

The mechanisms for cardiomyocyte death in cardiovascular diseases are incompletely understood. The aim of this study is to reveal the function of miR-381 in myocardium infarction (MI)-induced cardiomyocyte apoptosis. We established mouse model of MI and cellular models of apoptosis induced by oxidative stress (H₂O₂ and hypoxia/reoxygenation (H/R)). The expression of miR-381 in these models was assessed by quantitative reverse transcription polymerase chain reaction (qRT-PCR); we employed approaches including cell counting kit-8 (CCK-8) assay and flow cytometry to evaluate the cell viability and apoptosis. Notch signaling was determined by western blot analysis of key signaling components including Notch1 intracellular domain (ICD), Jag1, and Hes1. The predicted binding of miR-381 to Jag1 3' untranslated region (UTR) was validated by luciferase assay. Following MI, miR-381 expression was upregulated time dependently in the border zone of ischemic area but not in the non-ischemic area. MiR-381 expression was also upregulated in cardiomyocytes treated with H₂O₂ and H/R. Overexpression of miR-381 exacerbated H₂O₂- and H/R-induced apoptosis of cardiomyocytes; in contrast, inhibition of miR-381 attenuated apoptosis in these conditions. Importantly, in vivo delivery of miR-381 antagomir significantly reduced infarction size. Moreover, miR-381 negatively regulates the cardioprotective Notch signaling in vivo and in vitro, which might be an effect of targeted inhibition of Jag1 by itself. These data indicate an essential role of miR-381/Jag1 pathway in regulating Notch signaling-mediated cardioprotective effect in cardiomyocytes. Our study also provides a potential therapeutic target for cardiovascular diseases.

Analysis of change in microRNA expression profiles of lung cancer A549 cells treated with Radix tetrastigma hemsleyani flavonoids

Background

The aim of this study was to determine the inhibition effects of Radix tetrastigma hemsleyani (RTH) flavonoids on human lung adenocarcinoma A549 cells and the underlying molecular mechanism. RTH is an important Chinese traditional herb that has been widely used in cancer therapy. As an important type of active substance, RTH flavones (RTHF) have been shown to have good antiproliferative effects on various cancer cells. MicroRNAs (miRNAs) are small, noncoding RNA molecules that play important roles in cancer progression and prevention. However, the miRNA profile of RTHF-treated A549 cells has not yet been studied.

Materials and methods

The miRNA expression profile changes of A549 cell treated with RTHF were determined using the miRNA-seq analysis. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of differentially expressed miRNAs' (DE-miRNAs) target genes were carried out.

Results

In this study, we identified 162 miRNAs that displayed expression changes >1.2-fold in RTHF-treated A549 cells. GO analysis results showed that target genes of DE-miRNAs were significantly enriched in protein binding, binding, cell, cell part, intracellular, cellular process, single-organism process, and single-organism cellular process. Pathway analysis illustrated that target genes of DE-miRNAs are mainly involved in endocytosis, axon guidance, lysosome, melanogenesis, and acute myeloid leukemia pathway.

Conclusion

These results may assist in the better understanding of the anticancer effects of RTHF in A549 cells.

Expression and role of VEGFA and miR-381 in portal vein tumor thrombi in patients with hepatocellular carcinoma

The aim of the present study was to examine the expression and role of vascular endothelial growth factor A (VEGFA) and microRNA (miRNA or miR)-381 in tumor thrombi from patients with hepatocellular carcinoma and portal vein tumor thrombus (PVTT). Tumor thrombi and adjacent paired tissues were collected from 39 patients with hepatocellular carcinoma with PVTT. VEGFA expression levels were assessed using reverse transcription-quantitative polymerase chain reaction and western blotting. miRNAs that may regulate VEGFA expression were predicted using bioinformatics analysis and confirmed via a dual luciferase reporter assay. The effects of VEGFA and its upstream miRNA on proliferation of the proliferation of EAhy926 human venous endothelial cells were analyzed using an MTT assay. Compared with the paired adjacent tissues, VEGFA was significantly upregulated at both the mRNA and protein level in tumor thrombi (P<0.05). VEGFA was predicted to be a target of miR-381 and this was confirmed experimentally. miR-381 expression was significantly downregulated in tumor thrombi from patients with PVTT compared with paired adjacent tissues (P<0.05). In addition, transfection with antagomirs against miR-381 or short interfering RNA against VEGFA significantly inhibited EAhy926 cell proliferation (P<0.05). In conclusion, the results of the present study indicate that VEGFA is upregulated in tumor thrombi whereas miR-381 is downregulated. VEGFA is regulated by miR-381 and both may be associated with the development of PVTT.

MicroRNA-381 regulates the occurrence and immune responses of coronary atherosclerosis via cyclooxygenase-2

The present study aimed to measure the levels of microRNA-381 (miR-381) in the plaque tissues, peripheral blood mononuclear cells (PBMCs) and serum of patients with coronary atherosclerosis. In addition, the regulatory mechanisms of miR-381 and cyclooxygenase (COX)-2 in coronary atherosclerosis were investigated. A total of 36 patients with coronary atherosclerosis who received coronary endarterectomy at Linyi People's Hospital and Junan Hospital of Traditional Chinese Medicine (Linyi, China) between January 2013 and June 2016 were enrolled into the present study, while 39 healthy subjects were included as the control group. Peripheral blood was collected form all patients and healthy subjects. Plaque tissues were resected from patients with coronary atherosclerosis and adjacent artery intimal tissues were resected as the control tissues. Using quantitative polymerase chain reaction, the levels of miR-381 and COX-2 mRNA in the plaque tissues, PBMCs and serum were determined. In addition, COX-2 protein expression in the plaque tissues and PBMCs was measured by western blotting, while enzyme-linked immunosorbent assay was utilized to examine the protein content in the serum. To identify the direct interaction between miR-381 and COX-2 mRNA, dual-luciferase reporter assay was also conducted. The levels of COX-2 mRNA and protein in the plaque tissues, PBMCs and serum of patients with coronary atherosclerosis were significantly elevated compared with those in the corresponding control groups. However, the expression of miR-381 was significantly reduced in the coronary atherosclerosis patients. Dual-luciferase reporter assay revealed that miR-381 was able to directly target the 3'-untranslated region of COX-2 mRNA to regulate the expression of COX-2. Therefore, the present study demonstrated that enhanced levels of COX-2 expression in patients with coronary atherosclerosis are associated with the downregulation of miR-381 expression, while miR-381 may regulate the occurrence and immune responses of coronary atherosclerosis via COX-2.

MicroRNA-381 protects myocardial cell function in children and mice with viral myocarditis via targeting cyclooxygenase-2 expression

The present study aimed to determine the expression of cyclooxygenase (COX)-2 and microRNA (miRNA/miR)-381 in the blood of children with viral myocarditis (VM), and investigate the association between COX-2 and miR-381 in the occurrence and development of the disease using a mouse model. A total of 26 children with VM (15 boys and 11 girls) were included in the present study. Peripheral blood was collected from all children. The mouse model of VM was constructed by coxsackievirus B3 (CVB3) infection. Peripheral blood and myocardial tissues were collected from all mice for analysis. Reverse transcription-quantitative polymerase chain reaction was used to determine the expression of COX-2 mRNA and miR-381 in serum and myocardial tissues. ELISA was used to measure the content of COX-2 protein in serum from humans and mice, and western blotting was employed to determine the expression of COX-2 protein in myocardial tissues from mice. Contents of creatine kinase (CK-MB) and lactate dehydrogenase (LDH) were evaluated using an automatic biochemical analyzer. A dual luciferase assay was conducted to identify interactions between COX-2 mRNA and miR-381. Children with VM had increased COX-2 levels and decreased miR-381 expression in peripheral blood, compared with those who had recovered from VM. CVB3 infection resulted in damage in the myocardium of mice, and elevated CK-MB and LDH contents. VM model mice exhibited increased COX-2 levels and decreased miR-381 expression in peripheral blood and myocardial tissues compared with normal mice. miR-381 binds to the 3'-untranslated seed regions of both human and mouse COX-2 mRNA to regulate their expression. The present study demonstrated that children with VM have decreased miR-381 expression and elevated COX-2 expression in peripheral blood. miR-381 may inhibit myocardial cell damage caused by CVB3 infection and protect myocardial cell function by targeting COX-2 expression.

Basic fibroblast growth factor promotes VEGF-C-dependent lymphangiogenesis via inhibition of miR-381 in human chondrosarcoma cells

A chondrosarcoma is a common, primary malignant bone tumor that can grow to destroy the bone, produce fractures and develop soft tissue masses. Left untreated, chondrosarcomas metastasize through the vascular system to the lungs and ultimately lead to large metastatic deposits of the malignant cartilage taking over lung volume and function. Vascular endothelial growth factor (VEGF)-C has been implicated in tumor-induced lymphangiogenesis and elevated expression of VEGF-C has been found to correlate with cancer metastasis. bFGF (basic fibroblast growth factor), a secreted cytokine, regulates biological activity, including angiogenesis and metastasis. We have previously reported on the important role of bFGF in angiogenesis in chondrosarcomas. However, the effect of bFGF in VEGF-C regulation and lymphangiogenesis in chondrosarcomas is poorly understood. In this investigation, we demonstrate a correlation exists between bFGF and VEGF-C in tissue specimens from patients with chondrosarcomas. To examine the lymphangiogenic effect of bFGF, we used human lymphatic endothelial cells (LECs) to mimic lymphatic vessel formation. We found that bFGF-treated chondrosarcomas promoted LEC tube formation and cell migration. In addition, bFGF knockdown inhibited lymphangiogenesis in vitro and in vivo. We also found that bFGF-induced VEGF-C is mediated by the platelet-derived growth factor receptor (PDGFR) and c-Src signaling pathway. Furthermore, bFGF inhibited microRNA-381 expression via the PDGFR and c-Src cascade. Our study is the first to describe the mechanism of bFGF-promoted lymphangiogenesis by upregulating VEGF-C expression in chondrosarcomas. Thus, bFGF could serve as a therapeutic target in chondrosarcoma metastasis and lymphangiogenesis.

Low expression of miR-381 is a favorite prognosis factor and enhances the chemosensitivity of osteosarcoma

Osteosarcoma (OS) is the most common primary bone malignancy with a poor prognosis for all races and both sexes. In this study, we found that miR-381 is a positive prognosis factor for OS patients that OS patients with a low expression of miR-381 had a longer survival time after surgical intervention, and miR-381 expression promotes MG-63 cell proliferation and cell invasion ability. Our results also showed a strong negative correlation between the expression of miR-381 and LRRC4 (brain relative specific expression gene) in OS tissues. This demonstrated that LRRC4 is a direct target gene of miR-381, and suppressing the expression of miR-381 increases the sensitivity of OS cells to chemotherapeutic drugs through the LRRC4-mediated mTOR pathway. In summary, miR-381 is an important biomarker in directing therapeutic intervention and predicting prognosis in OS patients.

MicroRNA-381-induced down-regulation of CXCR4 promotes the proliferation of renal tubular epithelial cells in rat models of renal ischemia reperfusion injury

This study aims to explore whether microRNA-381 (miR-381) mediating CXCR4 affects the renal tubular epithelial cells (RTEC) of renal ischemia reperfusion (I/R) injury. Forty-eight rats were assigned into the I/R (n = 24, successfully established as I/R model) and sham (n = 24) groups. After collecting kidney tissues, immunohistochemistry, and microvascular density (MVD) counting were conducted for CXCR4 positive expression and MVD numbers. RTECs were assigned into the sham, blank, negative control (NC), miR-381 mimics, miR-381 inhibitor, si-CXCR4, and miR-381 inhibitor + si-CXCR4 groups. RT-qPCR and Western blotting were performed for relative expressions in tissues and cells. Cell proliferation and apoptosis were measured by MTT assay and flow cytometry. Results showed that compared with the sham group, positive expression of CXCR4 and MVD number were higher in the I/R group, which exhibited decreased miR-381 and increased expression of CXCR4, stromal cell-derived factor-1 (SDF1), vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1 (HIF-1α) and Tie-2. Dual luciferase reporter gene assay verified that CXCR4 is a target gene of miR-381. MiR-381 expression was lower in the miR-381 inhibitor + si-CXCR4 and miR-381 inhibitor groups and higher in the miR-381 mimics group than the blank and NC groups. Compared with the blank and NC groups, the miR-381 mimics and si-CXCR4 groups exhibited higher cell proliferation but lower cell apoptosis and expression of CXCR4, SDF1, VEGF, HIF-1α, and Tie-2, whereas the miR-381 inhibitor group exhibited the opposite trend. In conclusion, miR-381 may promote RTEC proliferation in rats with renal I/R injury by down-regulating CXCR4.

Long Noncoding RNA CAT104 Promotes Cell Viability, Migration, and Invasion in Gastric Carcinoma Cells Through Activation of MicroRNA-381-Inhibiting Zinc Finger E-box-Binding Homeobox 1 (ZEB1) Expression

Gastric carcinoma (GC) remains the second leading cause of cancer-related deaths worldwide. Good biomarkers are of paramount importance for GC therapy. This study aimed to assess the role of long noncoding RNA (lncRNA) CAT104 in GC. We found that CAT104 was highly expressed in human GC NCI-N87, SGC7901, BGC823, BGC803, and AGS cells. Suppression of CAT104 decreased NCI-N87 cell viability, migration, and invasion, but promoted apoptosis. CAT104 knockdown enhanced the expression of microRNA-381 (miR-381) expression in NCI-N87 cells. miR-381 participated in the regulatory effects of CAT104 on NCI-N87 cell viability, migration, invasion, and apoptosis. Zinc finger E-box-binding homeobox 1 (ZEB1) was identified as a direct target of miR-381. Overexpression of ZEB1 reversed the miR-381 mimic-induced cell viability, migration, and invasion inhibition. Suppression of ZEB1 reversed the miR-381 inhibitor-induced activation of the c-Jun N-terminal kinase (JNK) pathway and Wnt/β-catenin signaling pathways in NCI-N87 cells. In conclusion, CAT104 might function as an oncogenic factor in GC cells via regulating the expression of miR-381 and ZEB1.

MicroRNA-381 inhibits cell proliferation and invasion in endometrial carcinoma by targeting the IGF-1R

Endometrial carcinoma (EC) is the sixth most common type of malignant tumor occurring in females. MicroRNAs (miRNAs) serve as oncogenes or tumor suppressors in human cancer and play important roles in tumorigenesis, and tumor development by regulating various processes. Thus, further investigation into miRNAs involved in EC formation and progression may aid in developing effective therapeutic strategies for patients with this disease. miRNA‑381 (miR‑381) is aberrantly expressed in multiple types of human cancer. However, the expression pattern, biological roles and underlying mechanisms of miR‑381 in EC are poorly understood. In the present study, the results showed that miR‑381 was downregulated in EC tissues and cell lines. Decreased miR‑381 expression correlated with the International Federation of Gynecology and Obstetrics stage, lymph nodes metastasis and myometrial invasion of EC. The ectopic expression of miR‑381 significantly inhibited the proliferation and invasion of EC cells. Through a series of experiments, the insulin‑like growth factor receptor 1 (IGF‑1R) was identified as a novel direct target of miR‑381 in EC. Furthermore, IGF‑1R was highly expressed in EC tissues and inversely correlated with miR‑381 levels. IGF‑1R overexpression partially abrogated the tumor‑suppressive effects of miR‑381 on the proliferation and invasion of EC cells. miR‑381 targeted IGF‑1R to inactivate the protein kinase B (AKT) and extracellular signal‑regulated kinase (ERK) signaling pathways in EC. These results suggest that miR‑381 acts as a tumor suppressor in EC by directly targeting IGF‑1R, and indirectly regulating the AKT and ERK signaling pathways. Thus, miR‑381 should be investigated as a prognostic biomarker and novel therapeutic target for the treatment of patients with EC.

MicroRNA-381 serves as a prognostic factor and inhibits migration and invasion in non-small cell lung cancer by targeting LRH-1

Accumulating evidence has demonstrated that aberrant miRNAs were involved in carcinogenesis and tumor progression by regulating oncogenes or tumor suppressor expression. Dysregulation of miR-381 has been reported in different tumors. However, the clinical roles and underlying mechanism in non-small cell lung cancer (NSCLC) remains to be elucidated. We found the expression of miR-381 was significantly downregulated in both NSCLC tissues and cell lines. Clinical analysis revealed the reduced miR-381 was obviously associated with advanced TNM stage and lymph node metastasis. Moreover, we disclosed that miR-381 was a novel independent prognostic marker for predicting 5-year survival of NSCLC patients. The ectopic overexpression of miR-381 inhibited cell migration and invasion in vitro and in vivo. Notably, miR-381 could modulate LRH-1 by directly binding to its 3'-UTR. In clinical samples of NSCLC, miR-381 inversely correlated with LRH-1 expression, which performed positive roles in NSCLC migration and invasion. Alteration of LRH-1 expression at least partially abolished the migration and invasion of miR-381 on NSCLC cells. Here, we identified LRH-1 as a functional target of miR-381 in NSCLC. In conclusion, our data indicated that miR-381 inhibited migration and invasion of NSCLC by targeting LRH-1, and may represent a novel potential therapeutic target and prognostic marker for NSCLC.

Serum-circulating miRNAs predict neuroblastoma progression in mouse model of high-risk metastatic disease

Background

Circulating miRNAs have momentous clinical relevance as prognostic biomarkers and in the progression of solid tumors. Recognizing novel candidates of neuroblastoma-specific circulating miRNAs would allow us to identify potential prognostic biomarkers that could predict the switch from favorable to high-risk metastatic neuroblastoma (HR-NB).

Results

Utilizing mouse models of favorable and HR-NB and whole miRnome profiling, we identified high serum levels of 34 and low levels of 46 miRNAs in animals with HR-NB. Preferential sequence homology exclusion of mouse miRNAs identified 25 (11 increased; 14 decreased) human-specific prognostic marker candidates, of which, 21 were unique to HR-NB. miRNA QPCR validated miRnome profile. Target analysis defined the candidate miRNAs' signal transduction flow-through and demonstrated their converged roles in tumor progression. miRNA silencing studies verified the function of select miRNAs on the translation of at least 14 target proteins. Expressions of critical targets that correlate tumor progression in tissue of multifarious organs identify the orchestration of HR-NB. Significant (>10 fold) increase in serum levels of miR-381, miR-548h, and miR-580 identify them as potential prognostic markers for neuroblastoma progression.

Conclusion

For the first time, we identified serum-circulating miRNAs that predict the switch from favorable to HR-NB and, further imply that these miRNAs could play a functional role in tumor progression.

MicroRNA-381 inhibits the metastasis of gastric cancer by targeting TMEM16A expression

Background

MicroRNA-381 (miR-381) has been reported to play suppressive or promoting roles in different malignancies. However, the expression level, biological function, and underlying mechanisms of miR-381 in gastric cancer remain poorly understood. Our previous study indicated that transmembrane protein 16A (TMEM16A) contributed to migration and invasion of gastric cancer and predicted poor prognosis. In this study, we found that miR-381 inhibited the metastasis of gastric cancer through targeting TMEM16A expression.

Methods

MiR-381 expression was analyzed using bioinformatic software on open microarray datasets from the Gene Expression Omnibus (GEO) and confirmed by quantitative RT-PCR (qRT-PCR) in human gastric cancer tissues and cell lines. Cell proliferation was investigated using MTT and cell count assays, and cell migration and invasion abilities were evaluated by transwell assay. Xenograft nude mouse models were used to observe tumor growth and pulmonary metastasis. Luciferase reporter assay, western blot, enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry were employed to explore the mechanisms of the effect of miR-381 on gastric cancer cells.

Results

MiR-381 was significantly down-regulated in gastric cancer tissues and cell lines. Low expression of miR-381 was negatively related to lymph node metastasis, advanced tumor stage and poor prognosis. MiR-381 decreased gastric cancer cell proliferation, migration and invasion in vitro and in vivo. TMEM16A was identified as a direct target of miR-381 and the expression of miR-381 was inversely correlated with TMEM16A expression in gastric cancer tissues. Combination analysis of miR-381 and TMEM16A revealed the improved prognostic accuracy for gastric cancer patients. Moreover, miR-381 inhibited TGF-β signaling pathway and down-regulated epithelial–mesenchymal transition (EMT) phenotype partially by mediating TMEM16A.

Conclusions

MiR-381 may function as a tumor suppressor by directly targeting TMEM16A and regulating TGF-β pathway and EMT process in the development of progression of gastric cancer. MiR-381/TMEM16A may be a novel therapeutic candidate target in gastric cancer treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0499-z) contains supplementary material, which is available to authorized users.

MicroRNA-106a targets autophagy and enhances sensitivity of lung cancer cells to Src inhibitors

OBJECTIVES

Src tyrosine kinase inhibitors (TKIs) significantly inhibit cell migration and invasion in lung cancer cell lines with minor cytotoxic effects. In clinical trials, however, they show modest activity in combination with chemotherapeutic agents. Possible resistance mechanisms include the induction of cytoprotective autophagy upon Src inhibition. Autophagy is a cellular recycling process that allows cell survival in response to a variety of stress stimuli including responses to various treatments.

MATERIAL AND METHODS

We screened autophagic activity in A549, H460, and H1299 NSCLC cell lines treated with two different Src-TKIs (saracatinib, dasatinib) or shRNA targeting SRC. The autophagy response was determined by LC3B-I to -II conversion, increased ULK1 epxression and increased GFP-LC3B dot formation. Autophagy was inhibited by pharmacological (bafilomycin A, chloroquine) or genetic (ULK1 shRNA) means. Expression of miR-106a and miR-20b was analyzed by qPCR, and we used different lentivral vectors for ectopic expression of either miR-106a mimetics, anti-sense miR-106a or different miR-106a-363 cluster constructs.

RESULTS

In the current study we found that Src-TKIs induce autophagy in lung adenocarcinoma cell lines and that a combination of autophagy and Src tyrosine kinase inhibition results in cell death. Moreover, Src-TKI induced autophagy depends on the induction of the key autophagy kinase ULK1. This ULK1 upregulation is caused by downregulation of the ULK1-targeting microRNA-106a. An inverse correlation of miR-106a and ULK1 expression was seen in lung adenocarcinoma. Accordingly, ectopic expression of miR-106a in combination with Src-TKI treatment resulted in significant cell death as compared to control transduced cells.

CONCLUSIONS

Autophagy protects lung adenocarcinoma cells from Src-TKIs via a newly identified miR-106a-ULK1 signaling pathway. The combined inhibition of Src and ULK1/autophagy might represent a promising treatment option for future clinical trials. Lastly, our data might challenge the term "oncogenic" miR-106a as it can promote sensitivity to Src-TKIs thereby underlining the context-dependent function of miRNAs.

Targeting miR-381-NEFL axis sensitizes glioblastoma cells to temozolomide by regulating stemness factors and multidrug resistance factors

MicroRNA-381 (miR-381) is a highly expressed onco-miRNA that is involved in malignant progression and has been suggested to be a good target for glioblastoma multiforme (GBM) therapy. In this study, we employed two-dimensional fluorescence differential gel electrophoresis (2-D DIGE) and MALDI–TOF/TOF-MS/MS to identify 27 differentially expressed proteins, including the significantly upregulated neurofilament light polypeptide (NEFL), in glioblastoma cells in which miR-381 expression was inhibited. We identified NEFL as a novel target molecule of miR-381 and a tumor suppressor gene. In human astrocytoma clinical specimens, NEFL was downregulated with increased levels of miR-381 expression. Either suppressing miR-381 or enforcing NEFL expression dramatically sensitized glioblastoma cells to temozolomide (TMZ), a promising chemotherapeutic agent for treating GBMs. The mechanism by which these cells were sensitized to TMZ was investigated by inhibiting various multidrug resistance factors (ABCG2, ABCC3, and ABCC5) and stemness factors (ALDH1, CD44, CKIT, KLF4, Nanog, Nestin, and SOX2). Our results further demonstrated that miR-381 overexpression reversed the viability of U251 cells exhibiting NEFL-mediated TMZ sensitivity. In addition, NEFL-siRNA also reversed the proliferation rate of U251 cells exhibiting locked nucleic acid (LNA)-anti-miR-381-mediated TMZ sensitivity. Overall, the miR-381-NEFL axis is important for TMZ resistance in GBM and may potentially serve as a novel therapeutic target for glioma.

MiR-381 inhibits epithelial ovarian cancer malignancy via YY1 suppression

Epithelial ovarian cancer (EOC) is a common type of gynecologic cancer, which accounts for the majority of deaths among all gynecologic malignant tumors in developed countries. A series of recent studies suggested that miR-381 might play important roles in the development of various cancer types. However, the biological function of miR-381 in EOC remains to be investigated. We examined the levels of miR-381 expression in EOC tissues and cell lines. We identified miR-381 target genes by bioinformatic prediction. We also characterized the phenotype regarding cell proliferation, cell migration, and cell invasion in EOC cells lines with altered expression levels of both miR-381 and its target gene, YY1. The expression levels of miR-381 were downregulated in EOC tissues and cell lines. Overexpression of miR-381 significantly inhibited EOC cell proliferation, migration, and invasion. Restoration of YY1 expression partially reversed the phenotype induced by miR-381 overexpression. Knockdown of miR-381 target gene, YY1, mimicked the phenotype induced by miR-381 overexpression. MiR-381 regulated EOC cell through miR-381/YY1/p53 and miR-381/YY1/Wnt signaling axis. We concluded that miR-381 inhibited EOC cell proliferation, migration, and invasion, at least in part, via suppressing YY1 expression.

MicroRNA-381 suppresses cell growth and invasion by targeting the liver receptor homolog-1 in hepatocellular carcinoma

MicroRNAs (miRs) have emerged as prospective tools for human cancer therapy, including hepatocellular carcinoma (HCC) therapy. Previous studies have suggested that miR-381 functions as oncogenic or tumor-suppressive miRs in other cancer types. However, the role of miR-381 in HCC remains unknown. The present study investigated the expression and functional role of miR-381 in HCC. miR-381 expression was significantly decreased in HCC tissues and cell lines. miR-381 overexpression significantly inhibited HCC cell proliferation and colony formation, induced G0/G1 cell cycle arrest and suppressed cell invasion. Conversely, suppression of miR-381 showed the opposite effect in HCC cells. Bioinformatics analysis and dual-luciferase reporter assay results showed that miR-381 directly targeted the 3'-untranslated region of liver receptor homolog-1 (LRH-1), and quantitative polymerase chain reaction and western blot analysis results showed that miR-381 negatively modulated LRH-1 expression. Data elucidated that miR-381 directly regulated HCC cell growth and invasion, as well as the Wnt signaling pathways, by targeting LRH-1. Clinical tissue detection data revealed an inverse correlation between miR-381 and LRH-1 expression in HCC tissues, further indicating the functional significance of miR-381-LRH-1 in regulating HCC tumorigenesis. The present study indicates that miR-381 may be a novel tumor suppressor that blocks HCC growth and invasion by targeting LRH-1. The results present novel insights into understanding the molecular mechanism underlying HCC tumorigenesis and provide a future direction to the development of therapeutic interventions for HCC.

MicroRNA-381 Negatively Regulates TLR4 Signaling in A549 Cells in Response to LPS Stimulation

It is widely reported that miR-381 is dysregulated in various tumors. However, the specific role of miR-381 in respiratory infections has not been reported. To probe this role, A549 cells were pretreated with 1 μg/mL LPS for 24 h. The level of miR-381 was detected using RT-qPCR. The expression of proinflammatory cytokines was determined using an ELISA kit and western blotting. Bioinformatics analysis was used to predict the target genes of miR-381, and a luciferase reporter assay was used to validate the expression of the target genes. miR-381 expression was increased in A549 cells treated with LPS, which is a ligand of TLRs. Further study revealed that the overexpression of miR-381 increased the activity of NF-κB signaling, thereby increasing the expression of IL-6, TNFα, and COX-2. Further study revealed that IκBα was a target gene of miR-381. The upregulation of miR-381 under LPS stimulation contributes to respiratory infections mainly by targeting IκBα.

miR-381 suppresses C/EBPα-dependent Cx43 expression in breast cancer cells

miR-381 suppressed CX43 expression by directly targeting the 3′-UTR of C/EBPα, a novel transcription factor of Cx43 in human breast cancer cells. The miR-381–Cx43 axis might be a useful diagnostic and therapeutic target of metastatic breast cancer.

Cx43 (connexin43) is an enhancer of the metastasis of breast cancer cells. Our previous study identified miR-381 as an indirect suppressor of Cx43 gene expression, with the precise mechanism being not understood. In the present study, using a reporter gene assay, we found that miR-381 suppressed Cx43 gene expression via the promoter region −500/−250. With site-directed gene mutation, we demonstrated that miR-381 could directly bind with the sequences CACUUGUAU in the 3′-UTR so as to inhibit C/EBPα (CCAAT/enhancer-binding protein α) expression. C/EBPα was further identified as a novel transcription factor by binding to a canonic element (AATTGTC) locating at −459/−453 in the promoter region of the Cx43 gene. Functionally, we demonstrated that miR-381 suppressed C/EBPα- and Cx43-dependent migration and invasion of breast cancer cells. Finally, we revealed that decreased levels of miR-381 as well as increased expression of C/EBPα and Cx43 in the metastatic breast cancer cells and tissues. Therefore we are the first to identify that miR-381 suppresses C/EBPα-dependent Cx43 expression in breast cancer cells. The miR-381–C/EBPα–Cx43 axis might be a useful diagnostic and therapeutic target of metastatic breast cancer.

Down-regulation of MicroRNA-381 promotes cell proliferation and invasion in colon cancer through up-regulation of LRH-1

The expression and roles of MicroRNA-381 (miR-381) has been explored in several types of human cancers. However, its biological functions in colon cancer remain largely unknown. Quantitative real-time PCR assays were used to detect the expression of miR-381 in human colon cancer tissues and adjacent normal tissues. miR-381 antisense oligos and mimics were introduced into SW480 and HCT116 cells. Bioinformatic prediction analysis was performed to identify the potential targets of miR-381. Protein expression analysis, luciferase assays and rescue assays were used to confirm the substrate of miR-381. We found that miR-381 was significantly down-regulated in human colon cancer tissues, compared with adjacent normal tissues. Introduction of miR-381 antisense oligos into SW480 and HCT116 cells promoted cell proliferation and invasion. Besides, inhibition of miR-381 could also support tumor growth in the nude mice. Additionally, bioinformatic prediction suggested that the nuclear receptor liver receptor homologue 1 (LRH-1) is a target gene of miR-381. Thus, our data suggested that down-regulation of miR-381 plays an important role in the colon cancer progression.

Smoking status impacts microRNA mediated prognosis and lung adenocarcinoma biology

Background

Cigarette smoke is associated with the majority of lung cancers: however, 25% of lung cancer patients are non-smokers, and half of all newly diagnosed lung cancer patients are former smokers. Lung tumors exhibit distinct epidemiological, clinical, pathological, and molecular features depending on smoking status, suggesting divergent mechanisms underlie tumorigenesis in smokers and non-smokers. MicroRNAs (miRNAs) are integral contributors to tumorigenesis and mediate biological responses to smoking. Based on the hypothesis that smoking-specific miRNA differences in lung adenocarcinomas reflect distinct tumorigenic processes selected by different smoking and non-smoking environments, we investigated the contribution of miRNA disruption to lung tumor biology and patient outcome in the context of smoking status.

Methods

We applied a whole transcriptome sequencing based approach to interrogate miRNA levels in 94 patient-matched lung adenocarcinoma and non-malignant lung parenchymal tissue pairs from current, former and never smokers.

Results

We discovered novel and distinct smoking status-specific patterns of miRNA and miRNA-mediated gene networks, and identified miRNAs that were prognostically significant in a smoking dependent manner.

Conclusions

We conclude that miRNAs disrupted in a smoking status-dependent manner affect distinct cellular pathways and differentially influence lung cancer patient prognosis in current, former and never smokers. Our findings may represent promising biologically relevant markers for lung cancer prognosis or therapeutic intervention.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-778) contains supplementary material, which is available to authorized users.

MicroRNA modulation induced by AICA ribonucleotide in J1 mouse ES cells

ES cells can propagate indefinitely, maintain self-renewal, and differentiate into almost any cell type of the body. These properties make them valuable in the research of embryonic development, regenerative medicine, and organ transplantation. MicroRNAs (miRNAs) are considered to have essential functions in the maintenance and differentiation of embryonic stem cells (ES cells). It was reported that, strong external stimuli, such as a transient low-pH and hypoxia stress, were conducive to the formation of induced pluripotent stem cells (iPS cells). AICA ribonucleotide (AICAR) is an AMP-activated protein kinase activator, which can let cells in the state of energy stress. We have demonstrated that AICAR can maintain the pluripotency of J1 mouse ES cells through modulating protein expression in our previous research, but its effects on ES cell miRNA expression remain unknown. In this study, we conducted small RNA high-throughput sequencing to investigate AICAR influence on J1 mouse ES cells by comparing the miRNA expression patterns of the AICAR-treated cells and those without treatment. The result showed that AICAR can significantly modulate the expression of multiple miRNAs, including those have crucial functions in ES cell development. Some differentially expressed miRNAs were selected and confirmed by real-time PCR. For the differently expressed miRNAs identified, further study was conducted regarding the pluripotency and differentiation associated miRNAs with their targets. Moreover, miR-134 was significantly down-regulated after AICAR treatment, and this was suggested to be directly associated with the up-regulated pluripotency markers, Nanog and Sox2. Lastly, Myc was significantly down-regulated after AICAR treatment; therefore, we predicted miRNAs that may target Myc and identified that AICAR induced up-regulation of miR-34a, 34b, and 34c can repress Myc expression in J1 mouse ES cells. Taken together, our study provide a new mechanism for AICAR in ES cells pluripotency maintenance and give insight for its usage in iPS cells generation.

MicroRNAs-role in lung cancer

Regulation of gene expression is essential for normal physiological functions; thus deregulation of gene expression is common in disease conditions. One level of regulation of gene expression is performed by noncoding RNAs, among which microRNAs (miRNA) are the best studied. Abnormal expression of these molecular players can lead to pathogenic processes such as heart disease, immune system abnormalities, and carcinogenesis, to name but a few. Of a length of 18–25 nucleotides miRNAs are involved in binding partial complementary sequences within the 3′-UTR (3′-untranslated region) of the target mRNAs. Depending on the type of neoplastic transformation, miRNAs can act both as oncogenes (oncomirs) or as tumor suppressors. Because of the great importance of miRNAs, most researches focus on either their role as biomarkers or their potential as therapeutic targets. Herein, we present the review of microRNA biology, function, and tumorigenic potential with emphasis on their role in lung cancer.

microRNA therapies in cancer

MicroRNAs (miRNAs or miRs) are a family of small non-coding RNA species that have been implicated in the control of many fundamental cellular and physiological processes such as cellular differentiation, proliferation, apoptosis and stem cell maintenance. miRNAs regulate gene expression by the sequence-selective targeting of mRNAs, leading to translational repression or mRNA degradation. Some microRNAs have been categorized as “oncomiRs” as opposed to “tumor suppressor miRs” Modulating the miRNA activities may provide exciting opportunities for cancer therapy. This review highlights the latest discovery of miRNAs involved in carcinogenesis as well as the potential applications of miRNA regulations in cancer treatment. Several studies have demonstrated the feasibility of restoring tumor suppressive miRNAs and targeting oncogenic miRNAs for cancer therapy using in vivo model systems.

Crizotinib inhibits migration and expression of ID1 in MET-positive lung cancer cells: implications for MET targeting in oncology

ABSTRACT Aims: ID1 is an important component of the MET–SRC signaling pathway, which is a regulator of cell migration and invasion. We hypothesized that the ALK/MET inhibitor crizotinib inhibits migration via MET–SRC–ID1, rather than ALK. Materials & methods: We used ALK fusion-positive and -negative lung cancer cell lines; crizotinib, PHA-665752, and saracatinib, and stable transfection with shMET. We performed western blotting for p-ALK, ALK, p-MET, MET, p-SRC, SRC and ID1, and quantitative real-time PCR for ID1. Results: Crizotinib decreased p-MET, p-SRC and ID1 levels in ALK- and or MET-positive cell lines and inhibited cell migration. Knockdown of MET was comparable with the effect of crizotinib. Conclusion: The effects of crizotinib on ID1 expression and cancer cell migration were associated with the presence of activated MET, rather than ALK fusion.

The ID proteins: master regulators of cancer stem cells and tumour aggressiveness

Inhibitor of DNA binding (ID) proteins are transcriptional regulators that control the timing of cell fate determination and differentiation in stem and progenitor cells during normal development and adult life. ID genes are frequently deregulated in many types of human neoplasms, and they endow cancer cells with biological features that are hijacked from normal stem cells. The ability of ID proteins to function as central 'hubs' for the coordination of multiple cancer hallmarks has established these transcriptional regulators as therapeutic targets and biomarkers in specific types of human tumours.

SMARCB1 expression in epithelioid sarcoma is regulated by miR-206, miR-381, and miR-671-5p on Both mRNA and protein levels

Proximal type epithelioid sarcoma shares similarities with malignant rhabdoid tumor, including the lack of nuclear immunoreactivity of SMARCB1. Biallelic mutation of SMARCB1 has been convincingly established as the cause of loss of protein expression in rhabdoid tumor, but the cause in epithelioid sarcoma remains unknown. In our previous work, we demonstrated that DNA hypermethylation and post-translational modification mechanisms were not involved. In this current work, we explored the hypothesis that miRNAs regulate SMARCB1 gene expression in epithelioid sarcomas. In silico target prediction analysis revealed eight candidate miRNAs, and quantitative PCR-in 32 formalin-fixed, paraffin-embedded tumor samples comprising 30 epithelioid sarcomas and two malignant rhabdoid tumors-demonstrated significant (P < 0.001) overexpression of four miRNAs in epithelioid sarcomas: miR-206, miR-381, miR-671-5p, and miR-765. Two human tumors (fibrosarcoma and colon adenocarcinoma) and a normal cell line (human dermal fibroblast) with retained SMARCB1 expression were cultured for miRNA transient transfection (electroporation) experiments. SMARCB1 mRNA expression was analyzed by quantitative real-time PCR and immunostaining of SMARCB1 was performed to examine the effect of miRNAs transfections on both RNA and protein levels. Only three of the overexpressed miRNAs (miR-206, miR-381, and miR-671-5p) could silence the SMARCB1 mRNA expression in cell cultures; most effectively miR-206. Transfection of miR-206, miR-381, miR-671-5p, and some combination of them also eliminated SMARCB1 nuclear staining, demonstrating a strong effect on not only mRNA but also protein levels. Our results suggest loss of SMARCB1 protein expression in epithelioid sarcoma is due to the epigenetic mechanism of gene silencing by oncomiRs.

Epigenetic Therapy in Lung Cancer - Role of microRNAs

Lung cancer is the leading cause of cancer deaths worldwide. microRNAs (miRNAs) are a class of small non-coding RNA species that have been implicated in the control of many fundamental cellular and physiological processes such as cellular differentiation, proliferation, apoptosis, and stem cell maintenance. Some miRNAs have been categorized as "oncomiRs" as opposed to "tumor suppressor miRs." This review focuses on the role of miRNAs in the lung cancer carcinogenesis and their potential as diagnostic, prognostic, or predictive markers.

Prognostic significance of serum miR-17-5p in lung cancer

miR-17-5p is abnormally expressed in various tumor types. The aim of this study was to investigate the expression level of miR-17-5p in serum of patients with lung cancer and to determine whether serum miR-17-5p expression is related to the prognosis of patients with lung cancer. RT-qPCR was used to examine expression of miRNA-17-5p in 20 pairs of lung cancer and adjacent normal tissues, and sera from 221 patients with lung cancer and 54 matched controls. The correlation of serum miR-17-5p with clinicopathological factors or prognosis of patients with lung cancer was analyzed. The expression level of miR-17-5p obviously increased in lung cancer tissues (P = 0.004). Furthermore, serum miR-17-5p expression also significantly increased in patients with lung cancer compared with healthy individuals (P = 0.03). The survival analysis showed that serum miR-17-5p expression was closely related to the survival of patients with lung cancer. Patients with high miR-17-5p expression had shorter survival times [hazard ratio (HR) = 1.767, 95 %CI 1.039-3.005, P = 0.035]. A lower expression level of serum miR-17-5p helps extend the survival of patients with lung cancer. Thus, miR-17-5p may be potential biomarker for prediction the prognosis in patients with lung cancer.