MicroRNA-503 acts as a tumor suppressor in osteosarcoma by targeting L1CAM

Identification of Key Genes and Pathways in Osteosarcoma by Bioinformatics Analysis

Purpose

Osteosarcoma (OS) is the most primary bone malignant tumor in adolescents. Although the treatment of OS has made great progress, patients' prognosis remains poor due to tumor invasion and metastasis.

Materials and Methods

We downloaded the expression profile GSE12865 from the Gene Expression Omnibus database. We screened differential expressed genes (DEGs) by making use of the R limma software package. Based on Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis, we performed the function and pathway enrichment analyses. Then, we constructed a Protein-Protein Interaction network and screened hub genes through the Search Tool for the Retrieval of Interacting Genes.

Result

By analyzing the gene expression profile GSE12865, we obtained 703 OS-related DEGs, which contained 166 genes upregulated and 537 genes downregulated. The DEGs were primarily abundant in ribosome, cell adhesion molecules, ubiquitin-ubiquitin ligase activity, and p53 signaling pathway. The hub genes of OS were KDR, CDH5, CD34, CDC42, RBX1, POLR2C, PPP2CA, and RPS2 through PPI network analysis. Finally, GSEA analysis showed that cell adhesion molecules, chemokine signal pathway, transendothelial migration, and focal adhesion were associated with OS.

Conclusion

In this study, through analyzing microarray technology and bioinformatics analysis, the hub genes and pathways about OS are identified, and the new molecular mechanism of OS is clarified.

Regulation of Osteoclastogenesis and Bone Resorption by miRNAs

Osteoclasts are specialized bone-resorbing cells that contribute to physiological bone development and remodeling in bone metabolism throughout life. Abnormal production and activation of osteoclasts lead to excessive bone resorption in pathological conditions, such as in osteoporosis and in arthritic diseases with bone destruction. Recent epigenetic studies have shed novel insight into the dogma of the regulation of gene expression. microRNAs belong to a category of epigenetic regulators, which post-transcriptionally regulate and silence target gene expression, and thereby control a variety of biological events. In this review, we discuss miRNA biogenesis, the mechanisms utilized by miRNAs, several miRNAs that play important roles in osteoclast differentiation, function, survival and osteoblast-to-osteoclast communication, and their translational potential and challenges in bone biology and skeletal diseases.

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.

miRNA-216 knockdown has effects to suppress osteosarcoma via stimulating PTEN

The aim of this study is to explain the effects and mechanism of miRNA-216 in osteosarcoma. We firstly evaluated the PTEN expression in 30 pairs of tumor and adjacent tissues which were from the 30 osteosarcoma patients. In the following cell experiments, we measured the cell proliferation, cell cycle, cell invasion, and migration abilities of NC (normal control) group, BL (blank) group, siRNA (miRNA-216 inhibitor) group, and siRNA+PTEN inhibitor group. Furthermore, we measured the relative protein expression of difference groups by WB to explain the mechanism of miRNA-216 in osteosarcoma. The PTEN was confirmed the target gene of miRNA-216 by double luciferase target test. In conclusion, miRNA-216 was an oncogene in osteosarcoma. miRNA-216 knockdown had effects to suppress cancer cell proliferation, invasion and migration and improve cell apoptosis by keeping in G1 phase via PTEN.

Wnt-regulating microRNAs role in gastric cancer malignancy

Gastric cancer (GC) is responsible for high morbidity and mortality worldwide. This cancer claims fifth place among other cancers. There are a number of factors associated with GC development such as alcohol consumption and tobacco smoking. It seems that genetic factors play significant role in GC malignancy and progression. MicroRNAs (miRs) are short non-coding RNA molecules with negative impact on the expression of target genes. A variety of studies have elucidated the potential role of miRs in GC growth. Investigation of molecular pathways has revealed that miRs function as upstream modulators of Wnt signaling pathway. This signaling pathway involves in important biological processes such as cell proliferation and differentiation, and its dysregulation is associated with GC invasion. At the present review, we demonstrate that how miRs regulate Wnt signaling pathway in GC malignancy.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.

Medical image encryption using fractional discrete cosine transform with chaotic function

In this advanced era, where we have high-speed connectivity, it is very imperative to insulate medical data from forgery and fraud. With the regular increment in the number of internet users, it is challenging to transmit the beefy medical data. This (medical data) is always reused for different diagnosis purposes, so the information of the medical images need to be protected. This paper introduces a new scheme to ensure the safety of the medical data, which includes the use of a chaotic map on the fractional discrete cosine transform (FrDCT) coefficients of the medical data/images. The imperative FrDCT provides a high degree of freedom for the encryption of the medical images. The algorithm consists of two significant steps, i.e., application of FrDCT on an image and after that chaotic map on FrDCT coefficients. The proposed algorithm discusses the benefits of FrDCT over fractional Fourier transform (FRFT) concerning fractional order α. The key sensitivity and space of the proposed algorithm for different medical images inspire us to make a platform for other researchers to work in this area. Experiments are conducted to study different parameters and challenges. The proposed method has been compared with state-of-the-art techniques. The results suggest that our technique outperforms many other state-of-the-art techniques. Graphical Abstract Overview of the proposed algorithm.

MicroRNA-503 serves an oncogenic role in retinoblastoma progression by directly targeting PTPN12

Numerous studies have demonstrated that microRNAs (miRNAs or miRs) are abnormally expressed in retinoblastoma (RB). miRNAs may serve a role in oncogene or tumor-suppressor activity in RB genesis and development by modulating various biological processes. miRNAs therefore, may be effective therapeutic targets for miRNA-based therapy in patients with RB. Recently it has been revealed that miR-503 may serve a role in various types of human cancer. However, the expression and functional roles of miR-503 are rarely reported in RB. In the current study, the expression of miR-503 was significantly upregulated in RB tissues and cell lines. In addition, Cell Counting Kit-8 and in vitro invasion assays were performed to assess cell proliferation and invasion, respectively. The results of the present study revealed that miR-503 inhibition impeded RB in vitro cell proliferation and invasion. Furthermore, protein tyrosine phosphatase nonreceptor type 12 (PTPN12) was demonstrated to be a direct target gene of miR-503 in RB cells. PTPN12 overexpression also led to the downregulation of miR-503 in RB cell proliferation and invasion. PTPN12 knockdown could therefore abrogate the effects of miR-503 downregulation in RB cells. In conclusion, the results demonstrated that miR-503 may serve a role in RB oncogenic activity progression by directly targeting PTPN12. Therefore, miR-503 may be a target for effective therapy in patients with RB.

MiR-503 suppresses cell proliferation and invasion of gastric cancer by targeting HMGA2 and inactivating WNT signaling pathway

Background

Abnormal expression of microRNAs (miRNAs) is related to human carcinogenesis. Although previous studies have shown that miR-503 expression in gastric cancer (GC) is downregulated, however, the underlying molecular mechanism for miR-503 involved in gastric cancer development is still largely unknown.

Methods

The relative expression of miR-503 in GC tissues and adjacent normal tissues was examined using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) analyses. In vitro, cell proliferation and invasion were evaluated by using CCK8, cell colony and transwell invasion assays. In vivo, xenograft tumor model was constructed to assess miR-503 expression whether affects tumor growth or not. Luciferase reporter assay, qRT-PCR and western blot assay were used to demonstrate HMGA2 is a target of miR-503.

Results

We demonstrated that miR-503 expression was significantly downregulated in GC tissues and cell lines compared to adjacent normal tissues and normal gastric mucosa cell lines, respectively. Lower miR-503 expression associated with tumor size, lymph node metastasis, and predicted a poor overall survival (OS) time in GC patients. Subsequently, in vitro, gain-function and loss-function assays confirmed that miR-503 overexpression significantly suppressed GC cell proliferation, colony formation and cell invasion, while decreased miR-503 expression had an adverse effect in GC cells. Furthermore, we found that miR-503 specifically targeted the 3′-UTR regions of HMGA2 mRNA and suppressed its protein expression. Overexpression of HMGA2 could reverse the miR-503 mediated inhibition of GC cell proliferation and invasion. In vivo, miR-503 overexpression dramatically reduced tumor growth. Moreover, we demonstrated that miR-503 suppressed WNT/β-catenin signaling by elevating GSK-3β and p-β-catenin expression, but decreased p-GSK-3β and β-catenin expression in GC cells.

Conclusion

These results provide that miR-503 expression acts as a predictor for GC prognosis and may have a potential application in GC therapy.

miR-503-3p induces apoptosis of lung cancer cells by regulating p21 and CDK4 expression

Studies have shown that microRNAs (miRNAs) can promote or suppress tumor growth and therefore act as targets for cancer therapy. Hsa-miR-503-5p, a mature miRNA derived from 5' ends of pre-miR-503, has been proved to regulate cell proliferation, transformation, migration and invasion. However, the biological function of miR-503-3p derived from 3' ends of pre-miR-503 has never been reported. In current study, we found that miR-503-3p inhibits lung cancer cell viability and induces cell apoptosis. To better understand the molecular mechanism underlying the miR-503-3p participating in this process, PCR array and RNA-sequencing (RNA-seq) were performed and some differential expression genes were discovered between NC and miR-503-3p treated groups. Biological interaction network showed that p21 and CDK4 are the most important proteins involving miR-503-3p signal pathway. Dual-luciferase assay results shown miR-503-3p directly regulates the expression of p21 by targeting 3'-UTR of its mRNA. These results shed light on the potential roles of miR-503-3p, indicating that it may act as an anti-oncogene factor to inhibit lung cancer cell viability.

miR-30a suppresses osteosarcoma proliferation and metastasis by downregulating MEF2D expression

Many studies have revealed that microRNAs (miRNAs) play crucial roles in cancer development and progression. miRNA-30a (miR-30a), as a member of the miR-30 family, has been implicated in various cancers. However, the role of miR-30a in osteosarcoma remains unclear. In the current study, we found that miR-30a was significantly downregulated in osteosarcoma tissues and cell lines by using quantitative real-time polymerase chain reaction (qRT-PCR). In addition, miR-30a could inhibit cancer cell growth, migration, and invasion in vitro. Furthermore, bioinformatics of miRNA target prediction and luciferase reporter assay indicated that MEF2D is a direct target of miR-30a. miR-30a was able to reduce the mRNA and protein expression of MEF2D as assessed using RT-PCR and Western blotting assay. Interestingly, overexpression of MEF2D partially reversed the miR-30a-reduced cell proliferation, migration, and invasion of osteosarcoma cell, indicating that miR-30a suppresses osteosarcoma cell proliferation and metastasis partially mediated by inhibition of MEF2D. Overall, our study demonstrated that miR-30a functions as a tumor suppressor by targeting MEF2D in osteosarcoma, providing a promising prognostic biomarker and a therapeutic strategy for osteosarcoma.

miR-503 suppresses the proliferation and metastasis of esophageal squamous cell carcinoma by triggering autophagy via PKA/mTOR signaling

MicroRNA (miR)-503 is involved in the regulation of the malignant phenotype in multiple tumor types, and has been proven to be a novel diagnostic and therapeutic target; however, its function and mechanisms of action have not yet been fully elucidated in esophageal squamous cell carcinoma (ESCC). In the current study, we detected miR‑503 expression by RT‑qPCR and found that miR‑503 expression was increased in ESCC, but negatively correlated with lymph node metastasis, TNM stage and tumor differentiation. Functionally, we confirmed that miR‑503 inhibited the proliferation and metastasis of ESCC cells by triggering cellular autophagy. Mechanistically, we confirmed that miR‑503 exerted its biological effects by targeting protein kinase CAMP‑activated catalytic subunit alpha (PRKACA) in ESCC by dual luciferase reporter assay. Moreover, miR‑503 was found to trigger autophagy in ESCC cells through the protein kinase A (PKA)/mammalian target of rapamycin (mTOR) pathway. Taken together, our results demonstrate that miR‑503 suppresses the proliferation and metastasis of ESCC via the activation of autophagy, mediated by the PKA/mTOR signaling pathway.

Enhanced antitumor activity of combined megestrol acetate and arsenic trioxide treatment in liver cancer cells

Liver cancer is an aggressive malignancy with a very high fatality rate. Although megestrol acetate (MA) and arsenic trioxide (ATO) have shown an antitumor effect in liver cancer cells, the therapeutic benefits of MA or ATO alone in patients with liver cancer were limited. The aim of the present study was to elucidate whether the co-treatment of MA/ATO could enhance antitumor efficacy in liver cancer cell lines (Hep G2 and BEL 7402) and explore the underlying anti-cancer mechanisms. The cell viability, apoptotic response and expression levels of associated proteins were detected by Cell Counting Kit-8 assay, flow cytometry and western blotting, respectively. An xenograft model in nude mice bearing a Hep G2 tumor was used to estimate tumor growth in vivo. Co-treatment with MA/ATO markedly improved the inhibition of cell viability, enhanced apoptosis, and increased the phosphorylation of p38, c-Jun N-terminal kinase 1/2 and extracellular signal-regulated kinase 1/2 on liver cancer cell lines. Furthermore, the tumor growth in the murine Hep G2 cancer xenograft model was significantly inhibited by combined treatment with MA/ATO. The results indicated that MA/ATO combined treatment enhanced antitumor efficacy and possessed potential application for treating liver cancer.

Whole transcriptome analysis identifies differentially regulated networks between osteosarcoma and normal bone samples

We performed whole transcriptome analysis of osteosarcoma bone samples. Initially, we sequenced total RNA from 36 fresh-frozen samples (18 tumoral bone samples and 18 non-tumoral paired samples) matching in pairs for each osteosarcoma patient. We also performed independent gene expression analysis of formalin-fixed paraffin-embedded samples to verify the RNAseq results. Formalin-fixed paraffin-embedded samples allowed us to analyze the effect of chemotherapy. Data were analyzed with DESeq2, edgeR and Reactome packages of R. We found 5365 genes expressed differentially between the normal bone and osteosarcoma tissues with an FDR below 0.05, of which 3399 genes were upregulated and 1966 were downregulated. Among those genes, BTNL9, MMP14, ABCA10, ACACB, COL11A1, and PKM2 were expressed differentially with the highest significance between tumor and normal bone. Functional annotation with the reactome identified significant changes in the pathways related to the extracellular matrix degradation and collagen biosynthesis. It was suggested that chemotherapy may induce the modification of ECM with important collagen biosynthesis. Taken together, our results indicate that changes in the degradation of extracellular matrix seem to be an important mechanism of osteosarcoma and efficient chemotherapy induces the genes related to bone formation. Impact statement Osteosarcoma is a rare disease but it is of interest to many scientists all over the world because the current standard treatment still has poor results. We sequenced total RNA from 36 fresh-frozen paired samples (18 tumoral bone samples and 18 non-tumoral paired samples) from osteosarcoma patients. We found that differences in the gene expressions between the normal and affected bones reflected the changes in the regulation of the degradation of collagen and extracellular matrix. We believe that these findings contribute to the understanding of OS and suggest ideas for further studies.

Long Noncoding RNA miR210HG Sponges miR-503 to Facilitate Osteosarcoma Cell Invasion and Metastasis

Long noncoding RNAs (lncRNAs) have been illustrated to function as important regulator in carcinogenesis and cancer progression. However, roles of lncRNA miR210HG (miR210 host gene) in osteosarcoma remain unclear. In this study, miR210HG expression level was significantly upregulated in 55 cases of osteosarcoma tissue samples compared to adjacent normal tissue. Besides, the aberrantly enhanced miR210HG expression predicted poor prognosis and lower survival rate. In vitro, miR210HG knockdown suppressed the osteosarcoma cell proliferation, invasion, and epithelial-mesenchymal transition-related marker (N-cadherin and vimentin) expression. In vivo, miR210HG silencing decreased the tumor growth. miR-503 was verified to be the target miRNA of miR210HG using bioinformatics online program and luciferase assay. Furthermore, miR-503 could reverse the role of miR210HG on osteosarcoma cells. In conclusion, our study indicates that miR210HG sponges miR-503 to facilitate osteosarcoma cell invasion and metastasis, revealing the oncogenic role of miR210HG on osteosarcoma cells.

MicroRNA‑503 serves an oncogenic role in laryngeal squamous cell carcinoma via targeting programmed cell death protein 4

Laryngeal squamous cell carcinoma (LSCC), the most common form of laryngeal carcinoma, is an aggressive malignancy that demonstrates the second highest rate of morbidity of all head and neck squamous cell carcinomas. The abnormal expression of microRNAs (miRs) has been demonstrated in a number of types of human cancer, and they have been demonstrated to be oncogenes or tumour suppressor genes. miR-503 has been studied in various types of human cancer; however, the expression level, roles and underlying mechanisms in LSCC remain unknown. In the present study, it was demonstrated that miR-503 was significantly upregulated in LSCC tissues and cell lines. The level of miR-503 in LSCC tissues was correlated with thyroid cartilage invasion, lymph node metastasis, and tumour, node and metastasis stage. In addition, down-regulation of miR-503 inhibited cell proliferation and invasion in LSCC. Programmed cell death protein 4 (PDCD4) was identified to be a direct target gene of miR-503. PDCD4 overexpression could mimic the roles of miR-503 underexpression in LSCC. Furthermore, PDCD4 was down-regulated in LSCC tissues and this correlated with the miR-503 expression level. In conclusion, these results suggested that miR-503 promotes tumour growth and invasion by directly targeting PDCD4. The identification of the miR-503/PDCD4 axis may provide novel targets for LSCC treatment and improve prognosis.

MicroRNAs with prognostic significance in osteosarcoma: a systemic review and meta-analysis

Introduction

This study aimed to elucidate the prognostic value of microRNAs (miRNAs) in patients with osteosarcoma.

Materials and Methods

Studies were recruited by searching PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure, and Wanfang data-bases (final search update conducted January 2017). Eligible studies were identified and the quality was assessed using multiple search strategies.

Results

A total of 55 articles that investigated the correlation between miRNA expression and either patient survival or disease recurrence in osteosarcoma was initially identified. Among these, 30 studies were included in the meta-analysis. The results of our meta-analysis revealed that elevated levels of miR-21, miR-214, miR-29, miR-9 and miR-148a were associated with poor prognosis in osteosarcoma. Additionally, downregulated miR-382, miR26a, miR-126, miR-195 and miR-124 expression indicated poor prognosis in osteosarcoma.

Conclusions

miRNAs may act as independent prognostic factors in patients with osteosarcoma and are useful in stratifying risk.

MicroRNA-503 suppresses cell proliferation and invasion in osteosarcoma via targeting insulin-like growth factor 1 receptor

MicroRNAs (miRs) are a class of small non-coding RNAs and have key roles in various cancer types. Recently, miR-503 has been reported to act as a tumor suppressor in osteosarcoma. However, the detailed mechanism of the regulatory role of miR-503 in osteosarcoma cell proliferation and invasion has largely remained elusive. The present study found that miR-503 was significantly downregulated in osteosarcoma tissues compared to that in matched adjacent non-tumorous tissues. In addition, the expression of miR-503 in osteosarcoma of T3-T4 stage was significantly lower when compared with that in T1-T2 stage samples. miR-503 was also downregulated in osteosarcoma cell lines (Saos-2, MG63, U2OS and SW1353), when compared with that in the normal osteoblast cell line hFOB. Overexpression of miR-503 significantly inhibited the proliferation and invasion of U2OS cells and decreased the protein levels of insulin-like growth factor 1 receptor (IGF-1R), which was further identified as a novel target of miR-503 by a luciferase reporter assay. Moreover, overexpression of IGF-1R eliminated the suppressive effects of miR-503 on the proliferation and invasion of U2OS cells, suggesting that miR-503 inhibits osteosarcoma cell proliferation and invasion by directly targeting IGF-1R. Furthermore, IGF-1R was significantly upregulated in osteosarcoma tissues compared with that in adjacent non-tumor tissues, as well as in osteosarcoma cell lines compared with that in hFOB cells. In addition, the expression levels of IGF-1R were inversely correlated to the miR-503 levels in osteosarcoma tissues, suggesting that the increased IGF-1R expression may be caused by the reduced expression of miR-503. In conclusion, the present study demonstrated that miR-503 suppresses cell proliferation and invasion in osteosarcoma via targeting IGF-1R and thus highlights the importance of miR-503/IGF-1R signaling in the malignant progression of osteosarcoma.

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

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

MicroRNA-137 acts as a tumor suppressor in osteosarcoma by targeting enhancer of zeste homolog 2

MicroRNA (miR) are short non-coding RNA that bind to the 3′-untranslational region of their target genes, inhibiting translation and causing mRNA degradation. miR deregulation has been implicated in human cancer; however, the detailed regulatory mechanism of miR-137 in osteosarcoma (OS) remains largely unknown. In the present study, miR-137 and enhancer of zeste homologue 2 (EZH2) mRNA and protein expression levels were analyzed using reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. MTT and transwell assays were performed to evaluate cell viability and invasion capacities and a luciferase reporter gene assay was used to determine the targeting relationship. The results of the current study indicated that miR-137 expression was significantly downregulated in OS tissues and cell lines (P<0.01). Moreover, it was observed that low miR-137 expression levels were significantly associated with lung metastasis and advanced TMN stage (P<0.05), but not associated with age, gender, tumor size, location, serum lactate dehydrogenase or serum alkaline phosphatase. Increasing levels of miR-137 significantly inhibited U2OS cell viability and invasion (P<0.01). By contrast, knockdown of miR-137 markedly increased U2OS cell viability and invasion. EZH2 was identified as a direct target gene of miR-137 in U2OS cells by luciferase reporter assay and EZH2 expression was found to be significantly increased in OS tissues and cell lines (P<0.01). EZH2 was significantly downregulated following miR-137 overexpression (P<0.01), and was upregulated following miR-137 knockdown in U2OS cells. Furthermore, EZH2 overexpression significantly attenuated the suppressive effects of miR-137 on U2OS cell viability and invasion (P<0.01), suggesting that miR-137 inhibits the viability and invasion of OS cells by targeting EZH2. Therefore, the results of the current study suggest that the miR-137/EZH2 axis may be a potential target for novel potential therapeutic strategies to treat OS.

miR-424(322)/503 is a breast cancer tumor suppressor whose loss promotes resistance to chemotherapy

In this study, Rodriguez-Barrueco et al. analyzed ∼3000 primary tumors and show that miR-424(322)/503 is commonly lost in a subset of aggressive breast cancers; they then describe the genetic aberrations that inactivate its expression. Their data show that miR-424(322)/503 is a tumor suppressor in breast cancer and provide a link between mammary epithelial involution, tumorigenesis, and the phenomenon of chemoresistance.

The female mammary gland is a very dynamic organ that undergoes continuous tissue remodeling during adulthood. Although it is well established that the number of menstrual cycles and pregnancy (in this case transiently) increase the risk of breast cancer, the reasons are unclear. Growing clinical and experimental evidence indicates that improper involution plays a role in the development of this malignancy. Recently, we described the miR-424(322)/503 cluster as an important regulator of mammary epithelial involution after pregnancy. Here, through the analysis of ∼3000 primary tumors, we show that miR-424(322)/503 is commonly lost in a subset of aggressive breast cancers and describe the genetic aberrations that inactivate its expression. Furthermore, through the use of a knockout mouse model, we demonstrate for the first time that loss of miR-424(322)/503 promotes breast tumorigenesis in vivo. Remarkably, we found that loss of miR-424(322)/503 promotes chemoresistance due to the up-regulation of two of its targets: BCL-2 and insulin-like growth factor-1 receptor (IGF1R). Importantly, targeted therapies blocking the aberrant activity of these targets restore sensitivity to chemotherapy. Overall, our studies reveal miR-424(322)/503 as a tumor suppressor in breast cancer and provide a link between mammary epithelial involution, tumorigenesis, and the phenomenon of chemoresistance.

miR-24 represses metastasis of human osteosarcoma cells by targeting Ack1 via AKT/MMPs pathway

The expression levels of the protein tyrosine kinase Ack1 has been reported to be dysregulated in various cancers and involve in oncogenesis and progression. However, the expression and role of Ack1 in osteosarcoma remains unknown. In this study, we found that Ack1 were evidently upregulated in human osteosarcoma tissues and cell lines. In addition, the clinical data showed that high expression level of Ack1 is closely associated with clinical stage and positive distant metastasis, and negatively correlated with overall survival. Then, bioinformatics prediction and luciferase reporter assay indicated Ack1 as a direct target of miR-24, and Ack1 could be downregulated by miR-24 at both the mRNA and protein expression levels. Moreover, Ack1 expression levels were inversely correlated with that of miR-24 in osteosarcoma tissues. Furthermore, functional assay showed that miR-24 significantly suppressed osteosarcoma progression partially mediated by inhibiting Ack1 expression. Finally, western bolt assay revealed that miR-24 regulate AKT/MMPs pathway via Ack1 in osteosarcoma cells. In conclusion, our study demonstrated the suppression of miR-24 on osteosarcoma metastasis by targeting Ack1 via AKT/MMPs pathways, providing a novel strategy for the diagnosis and treatment of osteosarcoma patients.

miR-503 inhibits proliferation making human hepatocellular carcinoma cells susceptible to 5‑fluorouracil by targeting EIF4E

Hepatocellular carcinoma (HCC), a disease that is a major health care issue across the globe, includes the deviant expression of miRNAs in its development, progression, and resistance to treatment. We focused our study on miR‑503 expression and its role in HCC. miR‑503 was found in HCC tissues and cell lines using quantitative real-time PCR (RT‑qPCR). Western blot analyses and the luciferase reporter assay were used to determine the miR‑503 potential target in the HCC cells. We used MTT to analyze cell proliferation activity and noted that there was a considerable decrease of miR‑503 in HCC tissues and cell lines when measured against the controls. miR‑503 upregulation decreased expression of eukaryotic translation initiation factor 4E (EIF4E), and reduced HCC cell proliferation and sensitized HCC cells to anticancer drugs. miR‑503 overexpression hindered luciferase activity of EIF4E 3' untranslated region-based reporter construct among HepG2, BEL-7402, and SMMC-7721 cells, revealing that miR‑503 may increase sensitivity to therapies at least partially through targeting EIF4E suppression of HCC proliferation.

An integrative transcriptomics approach identifies miR-503 as a candidate master regulator of the estrogen response in MCF-7 breast cancer cells

Estrogen receptor α (ERα) is an important biomarker of breast cancer severity and a common therapeutic target. In response to estrogen, ERα stimulates a dynamic transcriptional program including both coding and noncoding RNAs. We generate a fine-scale map of expression dynamics by performing a temporal profiling of both messenger RNAs (mRNAs) and microRNAs (miRNAs) in MCF-7 cells (an ER+ model cell line for breast cancer) in response to estrogen stimulation. We identified three primary expression trends-transient, induced, and repressed-that were each enriched for genes with distinct cellular functions. Integrative analysis of mRNA and miRNA temporal expression profiles identified miR-503 as the strongest candidate master regulator of the estrogen response, in part through suppression of ZNF217-an oncogene that is frequently amplified in cancer. We confirmed experimentally that miR-503 directly targets ZNF217 and that overexpression of miR-503 suppresses MCF-7 cell proliferation. Moreover, the levels of ZNF217 and miR-503 are associated with opposite outcomes in breast cancer patient cohorts, with high expression of ZNF217 associated with poor survival and high expression of miR-503 associated with improved survival. Overall, these data indicate that miR-503 acts as a potent estrogen-induced candidate tumor suppressor miRNA that opposes cellular proliferation and has promise as a novel therapeutic for breast cancer. More generally, our work provides a systems-level framework for identifying functional interactions that shape the temporal dynamics of gene expression.

MicroRNA networks in pulmonary arterial hypertension: share mechanisms with cancer?

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) is a rare disease with poor prognosis and no therapeutics. PAH is characterized by severe remodeling of precapillary pulmonary arteries, leading to increased vascular resistance, pulmonary hypertension compensatory right ventricular hypertrophy, then heart failure and death. PAH pathogenesis shares similarities with carcinogenesis such as excessive cell proliferation, apoptosis resistance, metabolic shifts, or phenotypic transition. Although PAH is not a cancer, comparison of analogous mechanisms between PAH and cancer led to the concept of a cancer-like disease to emerge. MicroRNAs (miRNAs) are small noncoding RNAs involved in the regulation of posttranscriptional gene expression. miRNA dysregulations have been reported as promoter of the development of various diseases including cancers.

RECENT FINDINGS

Recent studies revealed that miRNA dysregulations also occur in PAH pathogenesis. In PAH, different miRNAs have been implicated to be the main features of PAH pathophysiology (in pulmonary inflammation, vascular remodeling, angiogenesis, and right heart hypertrophy).

SUMMARY

The review summarizes the implication of miRNA dysregulation in PAH development and discusses the similarities and differences with those observed in cancers.

Increased expression of microRNA-148a in osteosarcoma promotes cancer cell growth by targeting PTEN

Osteosarcoma is the most common type of primary malignant bone tumor, and deregulated microRNAs (miRNAs or miRs) in osteosarcoma have attracted great attention. In the present study, through miRNA microarray analysis, it was identified that miR-148a expression was significantly increased in osteosarcoma tissues. Increased miR-148a expression was significantly correlated with tumor progression and prognosis. Furthermore, increased miR-148a expression could promote osteosarcoma growth in vitro and in vivo, and the tumor-promoting effect was due to enhanced activation of the phosphoinositide 3-kinase signaling pathway caused by miR-148a-mediated inhibition of phosphatase and tensin homolog expression. Together, the present results suggest a role for miR-148a in osteosarcoma development and its potential use in prognosis prediction and cancer therapy.

L1-CAM knock-down radiosensitizes neuroblastoma IMR-32 cells by simultaneously decreasing MycN, but increasing PTEN protein expression

Childhood neuroblastoma is one of the most malignant types of cancers leading to a high mortality rate. These cancerous cells can be highly metastatic and malignant giving rise to disease recurrence and poor prognosis. The proto-oncogene myelocytomatosis neuroblastoma (MycN) is known to be amplified in this type of cancer, thus, promoting high malignancy and resistance. The L1 cell adhesion molecule (L1-CAM) cleavage has been found upregulated in many types of malignant cancers. In the present study, we explored the interplay between L1-CAM, MycN and PTEN as well as the role played by PDGFR and VEGFR on tumorigenicity in neuroblastoma cells. We investigated the effect of L1-CAM knock-down (KD) and PDGFR/VEGFR inhibition with sunitinib malate (Sutent®) treatment on subsequent tumorsphere formation and cellular proliferation and migration in the MycN-amplified IMR-32 neuroblastoma cells. We further examined the effect of combined L1-CAM KD with Sutent treatment or radiotherapy on these cellular functions in our cells. Tumorsphere formation is one of the indicators of aggressiveness in malignant cancers, which was significantly inhibited in IMR-32 cells after L1-CAM KD or Sutent treatment, however, no synergistic effect was observed with dual treatments, rather L1-CAM KD alone showed a greater inhibition on tumorsphere formation compared to Sutent treatment alone. In addition, cellular proliferation and migration were significantly inhibited after L1-CAM KD in the IMR-32 cells with no synergistic effect observed on the rate of cell proliferation when combined with Sutent treatment. Again, L1-CAM KD alone exhibited greater inhibitory effect than Sutent treatment on cell proliferation. L1-CAM KD led to the simultaneous downregulation of MycN, but the upregulation of PTEN protein expression. Notably, radiotherapy (2 Gy) of the IMR-32 cells led to significant upregulation of both L1-CAM and MycN, which was abrogated with L1-CAM KD in our cells. In addition, L1-CAM KD radiosensitized the cells as exhibited by the synergistic effect on the reduction in cell proliferation compared to radiotherapy alone. Taken together, our data show the importance of L1-CAM interplay with MycN and PTEN on the MycN amplified neuroblastoma cell radioresistance, proliferation and motility.

MiR-503 inhibits hepatocellular carcinoma cell growth via inhibition of insulin-like growth factor 1 receptor

MicroRNAs (miRs) have been demonstrated to play key roles in the development and progression of hepatocellular carcinoma (HCC). However, the regulatory mechanism of miR-503 in HCC has not been fully uncovered. In this study, we found that miR-503 was significantly downregulated in HCC tissues compared to nontumorous liver tissues. Moreover, lower miR-503 levels were associated with the malignant progression of HCC, and the expression of miR-503 was also decreased in several common HCC cell lines compared to normal human liver cell line THLE-3. Overexpression of miR-503 inhibited proliferation but induced apoptosis of LM3 and HepG2 cells. Bioinformatical analysis and luciferase reporter assay further identified insulin-like growth factor 1 receptor (IGF-1R) as a novel target of miR-503 in 293T cells. Moreover, overexpression of miR-503 led to a significant decrease in the protein levels of IGF-1R, while knockdown of miR-503 enhanced its protein levels in LM3 and HepG2 cells. Besides, overexpression of IGF-1R reversed the effects of miR-503-mediated HCC cell proliferation and apoptosis, indicating that IGF-1R acts as a downstream effector of miR-503 in HCC cells. Furthermore, IGF-1R was found to be significantly upregulated in HCC tissues compared to nontumorous liver tissues. In addition, the mRNA levels of IGF-1R were inversely correlated to the miR-503 levels in the HCC tissues. Thus, we demonstrate that miR-503 inhibits the proliferation and induces the apoptosis of HCC cells, partly at least, by directly targeting IGF-1R, and suggest that IGF-1R may serve as a promising target for the treatment of HCC.

Promotion of tumour proliferation, migration and invasion by miR-92b in targeting RECK in osteosarcoma

MicroRNAs play important roles in the development of cancers. Although miR-92b has been reported to promote the tumorigenesis of some cancers, its role in osteosarcoma remains unknown. In the present study, we focused on the expression, function and mechanisms of miR-92b in osteosarcoma development. The miRNA miR-92b was up-regulated in osteosarcoma cell lines and tissues; miR-92b up-regulation correlated with poor prognosis in osteosarcoma. Overexpression of miR-92b promoted osteosarcoma cell proliferation, migration and invasion, which was abrogated by miR-92b inhibition. Reversion-inducing, cysteine-rich protein with kazal motifs (RECK) was identified as the direct and functional target of miR-92b in osteosarcoma. Importantly, restoring RECK expression abrogated increases in cell growth, motility and invasiveness induced by miR-92b RECK was down-regulated in osteosarcoma tissues, and its expression level negatively correlated with miR-92b Collectively, our results indicate that miR-92b acts as an oncogenic miRNA and may be a therapeutic target in osteosarcoma.

Validation of downregulated microRNAs during osteoclast formation and osteoporosis progression

Enhanced osteoclast formation and function have essential roles during post‑menopausal osteoporosis. A number of cytokines have been reported to regulate osteoclastogenesis and to be involved during the pathogenesis of osteoporosis. However, the regulation of osteolysis by microRNAs (miRNAs) has remained to be fully elucidated. The present study used a microarray analysis to identify a variety of miRNAs that are differentially expressed during osteoclast formation. Six down‑regulated miRNAs, miR‑21a‑5p, miR‑27a‑3p, let‑7i‑5p, miR‑22‑3p, miR‑340‑5p and miR‑23a‑5p, whose molecular mechanisms during osteoclast differentiation have not been reported previously, were further assessed. Using an osteoclast formation assay and a mouse model of progressive osteoporosis, the downregulation of these miRNAs was validated in vitro and in vivo. Of note, the expression patterns of these six miRNAs were associated with the progression of osteoporosis. Therefore, these miRNAs are of potential diagnostic and therapeutic value for osteolytic diseases.

MicroRNA-490-3p inhibits colorectal cancer metastasis by targeting TGFβR1

Background

Colorectal cancer (CRC) is one of the most common malignances worldwide. Metastasis is responsible for the rapid recurrence and poor prognosis of CRC. However, the underlying molecular mechanism of CRC metastasis remains largely unclear. In this study we purposed to investigate the expression and biological functions of miR-490-3p in CRC metastasis, as well as to identify its downstream target genes and influenced pathway.

Methods

The expression level of miR-490-3p in CRC cell lines, CRC adjacent normal tissues, non-metastasis and metastasis tissues were assessed by quantitative real-time PCR. Patient survivals were follow-up up to 7 years. Gain-of-function and loss-of-function study on cell migration and invasion abilities were carried out by transfection of miR-490-3p mimics or inhibitors respectively. The molecular targets of miR-490-3p were computationally identified and experimentally verified by dual-luciferase reporter assay and western blot. Functional rescue was also conducted to confirm miR-490-3p inhibits CRC metastasis by targeting TGF-β signaling pathway.

Results

miR-490-3p expression was persistently downregulated during CRC malignant progression, as well as in CRC cell lines. Artificially overexpression miR-490-3p in CRC cell lines inhibited cell migration and invasion abilities while knockdown miR-490-3p expression caused the reverse effects. TGFβR1 and MMP2/9 were the downstream targets of miR-490-3p in CRC. Inhibition of TGFβR1 could partially recover the tumor suppression effect of miR-490-3p.

Conclusion

miR-490-3p is downregulated during CRC malignant progression. miR-490-3p represses CRC cell migration and invasion abilities, partially by targeting to the TGF-β signaling pathway. Taken together, miR-490-3p is acting as a tumor suppressor in CRC.

MicroRNA-154 functions as a tumor suppressor in osteosarcoma by targeting Wnt5a

MicroRNAs (miRNAs) are small non-coding RNAs that are involved in tumor initiation and development by suppressing target gene expression. miRNA-154 has been shown to be important in tumorigenesis in many types of cancers. However, its role in osteosarcoma (OS) remains unknown. In the present study, we focused on the roles and mechanisms of miR‑154 in OS development. The results of quantitative RT‑PCR showed that miR‑154 expression was decreased in primary OS tumor samples and cell lines compared to levels in the matched adjacent normal tissues and human normal osteoblast cells (NHOst). Restoration of expression in U2OS cells inhibited cell proliferation, colony formation, migration and invasion, as well as induced cell cycle arrest at the G1 stage. Bioinformatic prediction suggested that Wnt5a is a target gene of miR‑154. It was further verified that Wnt5a is a target gene of miR‑150 in OS cells using luciferase assay, mRNA and protein expression analysis. Wnt5a was upregulated in OS cell lines and primary tumor samples, and its mRNA expression level was negatively correlated with the miR‑154 level in the OS tissues. Restored expression of Wnt5a weakened miR‑154‑mediated suppression of tumor progression. Taken together, these findings suggest that miR‑154 functions as a tumor suppressor in OS by partially suppressing Wnt5a expression.

Effect of miR-503 Down-Regulation on Growth and Invasion of Esophagus Carcinoma and Related Immune Function

Background

MicroRNA (miR) has been proved to be an important biomarker for tumors because it can regulate occurrence, progression, invasion, and metastasis of cancer. A previous study has shown the involvement of miR-503 in multiple gastrointestinal tumors. Its detailed role and immune regulatory function in esophagus carcinoma, however, remains unknown. This study thus investigated the effect of miR-503 in regulating growth, proliferation, and invasion of esophagus cancer and its influence on cytokine secretion.

Material/Methods

Esophagus carcinoma cell line EC9706 and normal esophageal epithelial cell line HEEC were transfected with miR-503 inhibitor. MTT assay was used to quantify the cell proliferation, and a Transwell chamber was used to evaluate cell invasion. Release of cytokines, including interleukin-2 (IL-2), IL-4, IL-10, and interferon-γ (IFN-γ), was measured by enzyme-linked immunosorbent assay (ELISA).

Results

MiR-503 expression was significantly elevated in esophagus carcinoma cells (p<0.05). The specific inhibition of miR-503 expression remarkably suppressed proliferation and invasion of tumor cells. It can also down-regulated IL-2 and IFN-γ expression and facilitate secretion of IL-4 and IL-10 when compared to the control group (p<0.05 in all ceases).

Conclusions

The inhibition of miR-503 can effectively inhibit tumor progression and improve immune function, suggesting its potency as a novel drug target for esophagus cancer treatment.

MicroRNA-150 functions as a tumor suppressor in osteosarcoma by targeting IGF2BP1

Osteosarcoma (OS) is the most common primary malignant bone tumor with high morbidity in young adults and adolescents. Increasing evidence has demonstrated that aberrant microRNA (miRNA) expression is involved in OS occurrence and development. miR-150 has been recently widely studied in many cancers, but not including OS. This study is aimed to investigate the expression and biological role of miR-150 in OS. Here, we found that miR-150 expression was consistently downregulated in OS tissues and cell lines compared with the matched adjacent normal tissues and human normal osteoblast cells (NHOst), and its expression was significantly correlated with lymph node metastasis and tumor-node-metastasis (TNM) stage. Functional study showed that restoration of miR-150 expression in OS cells could inhibit cell proliferation, migration, and invasion and induced apoptosis in vitro as well as suppressed tumor growth of OS in vivo. Mechanistically, IGF2 mRNA-binding protein 1(IGF2BP1) was confirmed to act as a direct target of miR-150, and the IGF2BP1 mRNA expression was inversely correlated with the level of miR-150 in OS tissues. In addition, downregulation of endogenous IGF2BP1 exhibited similar effects of overexpression of miR-150. Taken together, these findings suggest that miR-150 functions as a tumor suppressor in OS partially by targeting IGF2BP1.

miR-503 inhibits cell proliferation and induces apoptosis in colorectal cancer cells by targeting E2F3

OBJECTIVE

Colorectal cancer (CRC) is one of the major healthcare problems worldwide. A lot of miRNAs are aberrantly expressed in CRC and involved in its development and progression. The purpose of this study was to investigate the expression and function of miR-503 in CRC.

METHODS

miR-503 expression was detected in CRC tissues and cell lines by Quantitative real-time PCR. Cell proliferation was assessed by MTT assay. Cell apoptosis and cell cycle distribution were measured by flow cytometry. Moreover, luciferase reporter assay and western blot were performed to determine the potential target of miR-503 in CRC cells.

RESULTS

miR-503 was significantly decreased in CRC tissues and cell lines in comparison with controls. Overexpression of miR-503 in CRC cells remarkably inhibited cell proliferation and induced apoptosis. Furthermore, E2F3 was identified as a direct target of miR-503 in CRC cells and down-regulation of E2F3 had a similar effect as miR-503 overexpression on CRC cells. In addition, the expression of E2F3 was negatively correlated with miR-503 level in CRC tissues.

CONCLUSIONS

miR-503 inhibits cell proliferation and induces apoptosis by directly targeting E2F3 in CRC cells, indicating its potential application in CRC diagnosis and therapy.