microRNA-194 suppresses osteosarcoma cell proliferation and metastasis in vitro and in vivo by targeting CDH2 and IGF1R

Transcriptional regulation and therapeutic potential of cyclin-dependent kinase 9 (CDK9) in sarcoma

Sarcomas include various subtypes comprising two significant groups - soft tissue and bone sarcomas. Although the survival rate for some sarcoma subtypes has improved over time, the current methods of treatment remain efficaciously limited, as recurrent, and metastatic diseases remain a major obstacle. There is a need for better options and therapeutic strategies in treating sarcoma. Cyclin dependent kinase 9 (CDK9) is a transcriptional kinase and has emerged as a promising target for treating various cancers. The aberrant expression and activation of CDK9 have been observed in several sarcoma subtypes, including rhabdomyosarcoma, synovial sarcoma, osteosarcoma, Ewing sarcoma, and chordoma. Enhanced CDK9 expression has also been correlated with poorer prognosis in sarcoma patients. As a master regulator of transcription, CDK9 promotes transcription elongation by phosphorylation and releasing RNA polymerase II (RNAPII) from its promoter proximal pause. Release of RNAPII from this pause induces transcription of critical genes in the tumor cell. Overexpression and activation of CDK9 have been observed to lead to the expression of oncogenes, including MYC and MCL-1, that aid sarcoma development and progression. Inhibition of CDK9 in sarcoma has been proven to reduce these oncogenes' expression and decrease proliferation and growth in different sarcoma cells. Currently, there are several CDK9 inhibitors in preclinical and clinical investigations. This review aims to highlight the recent discovery and results on the transcriptional role and therapeutic potential of CDK9 in sarcoma.

Hsa_circ_0000591 drives osteosarcoma glycolysis and progression by sequestering miR-194-5p and elevating HK2 expression

Osteosarcoma (OS) is the most common bone tumour with a high risk of metastatic progression and recurrence after treatment. Circular RNA hsa_circ_0000591 (circ_0000591) plays a compelling role in OS aggressiveness. However, the function and regulatory mechanism of circ_0000591 need to be further elucidated. As a subject of this study, a differential circRNA circ_0000591 was screened by circRNA microarray expression profiling (GSE96964). Expression changes of circ_0000591 were detected using real-time quantitative polymerase chain reaction (RT-qPCR). Effects of circ_0000591 silencing on OS cell viability, proliferation, colony formation, apoptosis, invasion, and glycolysis were determined via functional experiments. The mechanism by which circ_0000591 functions as a molecular sponge for miRNAs was predicted using bioinformatics analysis and validated using dual-luciferase reporter and RNA pull-down assays. Xenograft assay was done to validate the function of circ_0000591. Circ_0000591 was strongly expressed in OS samples and cells. Silencing of circ_0000591 lessened cell viability, repressed cell proliferation, invasion, glycolysis, and promoted cell apoptosis. Importantly, circ_0000591 regulated HK2 expression by serving as a miR-194-5p molecular sponge. MiR-194-5p silencing impaired circ_0000591 downregulation-mediated suppression of OS cell malignancy and glycolysis. HK2 overexpression weakened the inhibiting impacts of miR-194-5p on OS cell malignancy and glycolysis. Also, circ_0000591 silencing decreased xenograft tumour growth in vivo. Circ_0000591 drove OS glycolysis and growth by upregulating HK2 by sequestering miR-194-5p. The study highlighted the tumour-promoting function of circ_0000591 in OS.

Overexpression Pattern of miR-301b in Osteosarcoma and Its Relevance with Osteosarcoma Cellular Behaviors via Modulating SNX10

Prior studies have noted the importance of microRNAs (miRNAs) in development and progression of osteosarcoma (OS), but the influence of miR-301b is less investigated. This investigation aimed to explore the biological role of miR-301b/SNX10 in OS. GSE28423 and GSE28424 arrays delivered the corresponding miR-301b and sorting nexin 10 (SNX10) expression levels in OS samples. miR-301b and SNX10 expressions were also measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blotting in cells. Cell counting kit (CCK)-8 and transwell analysis were applied to measure cell characteristics. Luciferase reporter assay and Pearson correlation analysis were used to detect the relevance between miR-301b and SNX10. miR-301b was extremely increased in OS tissues compared with normal tissues, while SNX10 was decreased. The proliferation, invasion, and migration capabilities were limited following a low expression level of miR-301b whereas miR-301b overexpression promoted cellular malignant behaviors. miR-301b negatively targeted SNX10. The elevated SNX10 expression highlighted the inhibitory function on cell proliferation, migration, and invasion in OS cells treated by miR-301b inhibitor. Reduction of miR-301b induced the decrease of epithelial-mesenchymal transition (EMT)-related markers including N-cadherin, Vimentin, and matrix metallo-proteinase 9 (MMP)9. These results are added to the complete expanding field of the potential effects of miR-301b in OS cell malignant behaviors and demonstrate its promising role for further use to treat human OS.

Curculigoside Represses the Proliferation and Metastasis of Osteosarcoma via the JAK/STAT and NF-κB Signaling Pathways

Curculigoside (Cur) is a natural component from Curculigo orchioides Gaertn, with various bioactivities. The function of Cur in the nervous system and osteoarthritis has been reported. However, its role in osteosarcoma (OS) needs to be investigated. Hence, we focus on probing the impact of Cur on OS. In vitro, cell counting kit 8 (CCK-8), flow cytometry and Transwell assay were used to investigate the effects of Cur on OS cell proliferation, apoptosis, migration and invasion. In vivo, we developed a xenograft model to figure out the effect of Cur on tumor growth in nude mice. Western blotting (WB) was conducted to compare the levels of Cur on apoptosis-related proteins (C-caspase-3, Bax, and Bcl-2), epithelial-mesenchymal transition (EMT)-related proteins (N-cadherin, Snail, and E-cadherin) and the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) and nuclear factor-κB (NF-κB) pathways in vitro and in vivo. In-vitro data testified that Cur treatment markedly hampered OS cells' growth, migration and invasion and intensified their apoptosis compared to that of the control group. In vivo, Cur treatment notably hampered the growth of OS tumors in mice. In addition, both in vitro and in vivo experiments demonstrated that the phosphorylation of JAK2, STAT3, and NF-κB were inhibited through Cur treatment. Furthermore, the inhibition of Cur in OS cells was demonstrated by up-regulating the expression of JAK/STAT and NF-κB pathways protein levels. In summary, the data suggest that Cur curbs OS growth by down-regulating the JAK/STAT and NF-κB pathways, which is an underlying therapeutic option for OS treatment.

Bioinformatics analyses of the pathogenesis and new biomarkers of chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is one of the major cause of global death. The purpose of our analysis was to detect a more reliable biomarker and small-molecule drug candidates and to identify the precise mechanisms involved in COPD.

METHODS

Three data sets were downloaded from the Gene Expression Omnibus database and analysed by Gene Expression Omnibus 2R. Functional enrichment analyses were performed by Metascape. We use the STRING data to build a protein-protein interaction network. The targets of differentially expressed microRNA (DE miRNA) were predicted by the miRWalk database. Small-molecule drugs were predicted on connectivity map.

RESULTS

A total of 181 differentially expressed genes and 35 DE miRNAs were confirmed. The protein-protein interaction network including all integrated differentially expressed genes was constructed, and 4 modules were filtrated. The module genes were relative to immune, inflammatory and oxidative stress functions according to a pathway analysis. The top 20 key genes were screened. Among the DE miRNAs found to be regulating key genes, miR-194-3p, MiR-502-5p, MiR-5088-5p, MiR-3127-5p, and miR-23a-5p might be the most significant due to their high number of connecting nodes in COPD. In addition, cephaeline, emetine, gabapentin, and amrinone were found to be potential drugs to treat COPD patients.

CONCLUSION

Our study suggests that miR-194-3p, miR-502-5p, and miR-23a-5p might participate in the nosogenesis of COPD. In addition, 4 potential small-molecule drugs were considered potentially useful for treating COPD patients.

Long non-coding RNA H19 acts as a microRNA-194 sponge to inhibit the apoptosis and promote the proliferation of hypertrophic scar fibroblasts

The effects of long non-coding RNAs (lncRNAs) on the proliferation of hypertrophic scars have been described. However, the underlying mechanisms are not well characterized. The present study aimed to investigate the mechanisms of lncRNA H19 in hypertrophic scars. The effects of the lncRNA H19 on the proliferation and apoptosis of hypertrophic scar fibroblasts (HSFs) were analyzed using 5'-Ethynyl-2'-deoxyuridine staining, flow cytometry, and MTT. The results revealed H19 promoted the proliferation and inhibited the apoptosis in HSF. In addition, the binding associations between H19 and microRNA-194 (miR-194), and miR-194 and insulin-like growth factor-I receptor (IGF1R) were identified using bioinformatics screening and verified using dual-luciferase assays. Furthermore, the effects of the IGF1R knockdown on H19-induced HSF phenotypes and regulation over the p38 MAPK pathway were determined. Mechanistically, miR-194 was identified as the downstream effector of the H19-mediated phenotypes of HSFs through its ability to directly target IGF1R, thus modulating the p38 MAPK signaling pathway. In conclusion, the findings suggested that H19 may inhibit the apoptosis and promote the proliferation of HSFs through the miR-194/IGF1R/p38 MAPK signaling axis, thereby contributing to the progression of hypertrophic scars. These findings may provide novel targets for the treatment of hypertrophic scars.

LncRNA JPX overexpressed in oral squamous cell carcinoma drives malignancy via miR-944/CDH2 axis

OBJECTIVES

Oral squamous cell carcinoma (OSCC) is a common head and neck cancer with high incidence. Numerous reports have elucidated that long non-coding RNAs (lncRNAs) serve as crucial regulatory factors in various diseases including cancer. Nonetheless, the role of lncRNA JPX in OSCC is still not elaborated.

SUBJECTS AND METHODS

In our research, we detected the expression of lncRNA JPX through qRT-PCR. Colony formation, EdU staining, Transwell, TUNEL, and caspase-3 activity assays were applied for estimating the function of lncRNA JPX in OSCC. RIP, pull-down, and luciferase reporter experiments were adopted to examine the interrelations between lncRNA JPX, miR-944, and CDH2.

RESULTS

LncRNA JPX was discovered as highly expressed in OSCC cells. Silencing lncRNA JPX restrained OSCC cell proliferation, migration, and invasion. Interestingly, lncRNA JPX bound with miR-944 and then augmented CDH2 via a competing endogenous RNA (ceRNA) mechanism. Importantly, overexpressed CDH2 recovered the suppression of silenced lncRNA JPX on the oncogenic behaviors of OSCC cells.

CONCLUSIONS

In short, lncRNA JPX contributes to OSCC cell proliferation, migration, and invasion via miR-944/CDH2 axis, which offers a new direction for potential targeted treatment of OSCC.

Treatment of dilated cardiomyopathy in a mouse model of Friedreich's ataxia using N-acetylcysteine and identification of alterations in microRNA expression that could be involved in its pathogenesis

Deficient expression of the mitochondrial protein, frataxin, leads to a deadly cardiomyopathy. Our laboratory reported the master regulator of oxidative stress, nuclear factor erythroid 2-related factor-2 (Nrf2), demonstrates marked down-regulation after frataxin deletion in the heart. This was due, in part, to a pronounced increase in Keap1. To assess if this can be therapeutically targeted, cells were incubated with N-acetylcysteine (NAC), or buthionine sulfoximine (BSO), which increases or decreases glutathione (GSH), respectively, or the NRF2-inducer, sulforaphane (SFN). While SFN significantly (p < 0.05) induced NRF2, KEAP1 and BACH1, NAC attenuated SFN-induced NRF2, KEAP1 and BACH1. The down-regulation of KEAP1 by NAC was of interest, as Keap1 is markedly increased in the MCK conditional frataxin knockout (MCK KO) mouse model and this could lead to the decreased Nrf2 levels. Considering this, MCK KO mice were treated with i.p. NAC (500- or 1500-mg/kg, 5 days/week for 5-weeks) and demonstrated slightly less (p > 0.05) body weight loss versus the vehicle-treated KO. However, NAC did not rescue the cardiomyopathy. To additionally examine the dys-regulation of Nrf2 upon frataxin deletion, studies assessed the role of microRNA (miRNA) in this process. In MCK KO mice, miR-144 was up-regulated, which down-regulates Nrf2. Furthermore, miRNA screening in MCK KO mice demonstrated 23 miRNAs from 756 screened were significantly (p < 0.05) altered in KOs versus WT littermates. Of these, miR-21*, miR-34c*, and miR-200c, demonstrated marked alterations, with functional clustering analysis showing they regulate genes linked to cardiac hypertrophy, cardiomyopathy, and oxidative stress, respectively.

Downregulation of serum miR-194 predicts poor prognosis in osteosarcoma patients

BACKGROUND

Circulating microRNAs (miRNAs) have promising potential as diagnostic and prognostic biomarkers for osteosarcoma. This study aimed to explore the expression pattern of serum miR-194 and its potential clinical value in patients with osteosarcoma.

METHODS

Messenger RNA was isolated from serum sample from 124 osteosarcoma patients, 60 periostitis patients and 60 healthy volunteers. The serum miR-194 level was then examined by quantitative real-time polymerase chain reaction (qRT-PCR). The bioinformatic analysis of the downstream targets of miR-194 was also performed.

RESULTS

The results showed serum miR-194 levels were significantly decreased in osteosarcoma patients compared to those in periostitis patients or healthy controls. Receiver-operating characteristic (ROC) analysis demonstrated that serum miR-194 had a good diagnostic value for identifying osteosarcoma subjects from periostitis patients and normal controls. In addition, serum miR-194 levels were dramatically increased following surgery in osteosarcoma cases. Moreover, low serum miR-194 expression was strongly correlated with positive metastasis and advanced clinical stage, as well as worse survival. Furthermore, serum miR-194 was confirmed to be an independent prognostic biomarker for osteosarcoma. Bioinformatic analysis showed that the downstream targeted genes of miR-194 were closely associated with cancer initiation and development.

CONCLUSION

In conclusion, our results have demonstrated that serum miR-194 might serve as a novel and promising biomarker for the detection and prognosis of osteosarcoma.

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.

Identification of critical genes associated with human osteosarcoma metastasis based on integrated gene expression profiling

Osteosarcoma is the most common type of malignant bone cancer, which often affects teenagers and young adults. The present study aimed to screen for critical genes and microRNAs (miRNAs/miRs) involved in osteosarcoma. A total of four microarray datasets (accession numbers GSE32981, GSE21257, GSE14827 and GSE14359) were downloaded from the Gene Expression Omnibus database. Following data preprocessing, module analysis was performed to identify the stable modules using the weighted gene co‑expression network analysis (WGCNA) package. The differentially expressed genes (DEGs) between metastatic samples and non‑metastatic samples were screened, followed by gene co‑expression network construction, and Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Subsequently, prognosis‑associated genes were screened and a miRNA‑target gene regulatory network was constructed. Finally, the data for critical genes were validated. WGCNA analysis identified six modules; blue and yellow modules were significantly positively associated with osteosarcoma metastasis. A total of 1,613 DEGs were screened between primary tissue samples and metastatic samples. Following comparison of the genes in the two (blue and yellow) modules, a total of 166 DEGs were identified (metastatic samples vs. non‑metastatic samples). Functional enrichment analysis demonstrated that these DEGs were mainly involved in 'defense response', 'p53 signaling pathway' and 'lysosome'. By utilizing the clinical information in GSE21257, 10 critical genes associated with osteosarcoma prognosis were obtained, including CTP synthase 2 (CTPS2), tumor protein p53 inducible protein 3 (TP53I3) and solute carrier family 1 member 1 (SLC1A1). In addition, hsa‑miR‑422a and hsa‑miR‑194 were highlighted in the miRNA‑target gene network. Finally, matrix metallopeptidase 3 (MMP3) and vascular endothelial growth factor B (VEGFB) were predicted as critical genes in osteosarcoma metastasis. CTPS2, TP53I3 and SLC1A1 may serve major roles in osteosarcoma development, and hsa‑miR‑422a, hsa‑miR‑194, MMP3 and VEGFB may be associated with osteosarcoma metastasis.

CDH2 gene rs11564299 polymorphism is a risk factor for knee osteoarthritis in a Chinese population: a case-control study

Background

Cadherin-2 (CDH2) gene polymorphisms were reported to be associated with the induction and development of knee osteoarthritis (OA).

Methods

This case–control study was designed to explore the association between CDH2 gene rs11564299 polymorphism and the risk of knee OA in Chinese subjects. The polymorphism was genotyped by polymerase chain reaction and Sanger sequencing.

Results

G allele or GG genotype of CDH2 gene rs11564299 polymorphism was related to increased risk for knee OA in the Chinese Han population. Additionally, subgroup analyses indicated that the female, smoker, drinker, and BMI ≥ 25 kg/m² groups showed increased risk for knee OA. Additionally, this polymorphism was associated with CRP and Kellgren–Lawrence grade.

Conclusion

In summary, this current study reveals that CDH2 gene rs11564299 polymorphism is a risk factor for knee OA development in this Chinese population. The genotypes distribution differed significantly among OA patients and healthy controls and may be a useful tool in the evaluation of OA susceptibility in Chinese Han population.

MicroRNA-194 overexpression protects against hypoxia/reperfusion-induced HK-2 cell injury through direct targeting Rheb

Renal ischemia-reperfusion injury, a major cause of renal failure, always leads to acute kidney injury and kidney fibrosis. MicroRNAs (miRs) have been reported to be associated with renal ischemia-reperfusion injury. miR-194 was downregulated following renal ischemia-reperfusion injury; however, the function and mechanism of miR-194 in renal ischemia-reperfusion injury have not yet been fully understood. In the present study, we constructed renal ischemia-reperfusion injury model in vitro through treatment of human kidney proximal tubular epithelial cells HK-2 by hypoxia/reperfusion (H/R). We observed that miR-194 was decreased in H/R-induced HK-2 cells. miR-194 mimic increased H/R-induced HK-2 cell survival, whereas miR-194 inhibitor further strengthened H/R- inhibited HK-2 cell survival. Also, we observed that miR-194 overexpression suppressed oxidative stress markers, including malondialdehyde, glutathione, and secretion of pro-inflammatory cytokines, including IL-6, IL-1β, and TNF-α; however, miR-194 inhibitor showed the reverse effects. Results from dual-luciferase analysis confirmed that Ras homology enriched in brain (Rheb) was a direct target of miR-194. Finally, we corroborated that miR-194 affected cell growth, oxidative stress, and inflammation through targeting Rheb in H/R-induced HK-2 cells. In conclusion, our results suggested that miR-194 protect against H/R-induced injury in HK-2 cells through direct targeting Rheb.

Up-regulation of microRNA-496 suppresses proliferation, invasion, migration and in vivo tumorigenicity of human osteosarcoma cells by targeting eIF4E

Osteosarcoma is an aggressive bone tumor characterized by a high level of genetic instability and recurring DNA deletions and amplifications. This study aims to investigate how microRNA-496 (miR-496) affects proliferation, invasion, and migration of human osteosarcoma (OS) cells and in vivo tumorigenicity by targeting eukaryotic translation initiation factor 4E (eIF4E). Microarray-based gene expression profiling involving OS was used in order to identify differentially expressed genes. After that, the interaction between miR-496 expression and OS patients' survival rate was determined. The expression pattern of miR-496 and eIF4E was determined in OS tissues and cells, and their potential relationship was further analyzed by using the dual luciferase reporter gene assay. With the purpose of identifying the functional role miR-496 in OS, cell proliferation, migration, and invasion were measured in cells treated with miR-496 mimic or inhibitor. A nude mouse model was constructed in order to investigate the regulatory effects of miR-496 on tumor growth in vivo by regulating eIF4E. OS cells exhibited a down-regulated expression of miR-496 and an up-regulated expression of eIF4E. miR-496 expression was positively correlated to OS patients' survival rate. Bioinformatics analysis suggested eIF4E would be a direct target of miR-496, and the expression of eIF4E was inhibited by overexpression of miR-496. miR-496 elevation was found to exert suppressive effects on OS cell proliferation, migration and invasion in vitro and tumor growth in vivo, with the effects being reversed using miR-496 depletion. Altogether, the above findings support a conclusion that miR-496 could work as a tumor suppressor in OS through down-regulation of eIF4E. This study may provide a novel target for treatment of OS.

Insights into the roles of miRNAs; miR-193 as one of small molecular silencer in osteosarcoma therapy

Today, cancer is one of the most common causes of death. Osteosarcoma (OS) is a tumor in long bones and its prevalence is high in teenagers and young people. Among the methods that used to treat cancer, one can name chemotherapy, surgery, and radiotherapy. Since these methods have some disadvantages and they are not absolutely successful, the use of microRNAs (miRNAs) is very useful in diagnosis and treatment of OS. MiRNAs are small non-coding RNA molecules, containing 18-25 nucleotides, which are involved in the regulation of gene expression via binding to messenger RNA (mRNA). These RNAs are divided into two classes of suppressors and oncogenes. During OS, there is aberrant expression of several miRNAs. Among these miRNAs are downregulation of miR-193 that has been associated with cancer occurrence. The aim of the current manuscript is to have overview on the treatment approaches of OS with special focus on miR-193.

MicroRNA-885-5p promotes osteosarcoma proliferation and migration by downregulation of cell division cycle protein 73 homolog expression

Osteosarcoma (OS) is the most common primary malignant bone tumor. Numerous studies have strongly implicated the ectopic expression of microRNAs (miRNAs/miRs), including miR-885-5p, which is aberrantly expressed in several cancer types, in multiple cancer-related processes. However, the role of miR-885-5p in OS remains unknown. In the present study, it was found that the expression of miR-885-5p was markedly upregulated in OS cell lines and clinical tissues. Moreover, high expression of miR-885-5p was significantly associated with the development of OS. The human OS MG-63 cell line was transfected with recombinant lentivirus to regulate miR-885-5p expression. Overexpressed miR-885-5p significantly promoted the proliferation and migration of MG-63 cells in vitro, while downregulating miR-885-5p expression reversed these effects. Furthermore, bioinformatic analysis was used to predict the potential target genes of miR-885-5p, and cell division cycle protein 73 homolog (CDC73) was identified as a novel and direct target of miR-885-5p. This interaction was further confirmed using reverse transcription-quantitative polymerase chain reaction, western blotting and luciferase activity assays. These findings suggest that miR-885-5p serves a critical role in facilitating OS proliferation and migration, and can regulate CDC73 expression in OS cells and tissues. Thus, miR-885-5p could be a promising novel therapeutic biomarker for OS.

Let-7b acts as a tumor suppressor in osteosarcoma via targeting IGF1R

MicroRNAs serve crucial functions in cancer progression by inhibiting the translation of target genes and causing mRNA degradation. However, the underlying regulatory mechanism of Let-7b in osteosarcoma (OS) has not, to the best of our knowledge, been comprehensively elucidated. The aim of the present study was to investigate the function of Let-7b in OS and clarify the regulation of insulin-like growth factor 1 receptor (IGF1R) by Let-7b. It was observed that Let-7b was significantly downregulated in OS tissues and cell lines compared with the matched adjacent non-tumorous tissues and human normal osteoblastic cell line hFOB 1.19. Overexpression of Let-7b significantly inhibited the proliferation and invasion of U2OS and SAOS-2 cells. A luciferase reporter assay validated that IGF1R was a downstream and functional target of Let-7b. Let-7b was also able to decrease the expression levels of IGF1R protein. Functional studies revealed that the antitumor effect of Let-7b was probably due to targeting and suppressing IGF1R expression. Furthermore, in OS tissues, IGF1R was identified to be significantly upregulated and negatively correlated with Let-7b levels. In conclusion, the results of the present study indicated that Let-7b suppresses OS cellular proliferation and invasion via targeting IGF1R. A novel candidate prognostic factor was identified and it is suggested that the Let-7b/IGF1R axis may represent a novel anti-metastasis therapeutic target in OS.

NAIF1 suppresses osteosarcoma progression and is regulated by miR-128

Nuclear apoptosis-inducing factor 1 (NAIF1) acts as an oncogene and involves in tumorigenesis in several cancers. However, the expression and mechanism of NAIF1 in osteosarcoma remains unclear. In this study, we demonstrated the downregulation of NAIF1 expression in both osteosarcoma tissues and cell lines. We next explored the potential role of NAIF1 in osteosarcoma cell proliferation and migration. The result showed that overexpression of NAIF1 evidently suppressed the cell proliferation and invasion of osteosarcoma. Furthermore, we investigated the potential mechanisms accounting for dysregulation of NAIF1 in osteosarcoma. The bioinformatic prediction and luciferase reporter assay revealed that miR-128 is a direct upstream regulator of NAIF1 and regulates NAIF1 expression by binding the 3'-UTR of NAIF1. Consistent with previous study, we found that miR-128 was upregulated in both osteosarcoma tissues and cell lines. Moreover, miR-128 expression levels were inversely correlated with that of NAIF1 in osteosarcoma tissues. Finally, functional assay showed that miR-128 significantly suppressed osteosarcoma progression partially mediated by inhibiting NAIF1 expression. These data indicate that the miR-128 and its target gene NAIF1 played important roles by regulating OS cell proliferation and migration phenotype. SIGNIFICANCE OF THE STUDY: Osteosarcoma (OS) is the most common malignant bone tumour and the second leading cause of cancer-related death affecting children and adolescents. Nuclear apoptosis-inducing factor 1 (NAIF1) plays an inhibitory role in the initial steps of different carcinomas. However, the expression and mechanism of NAIF1 in osteosarcoma remains unclear. The data of this study indicated that the miR-128 and its target gene NAIF1 played important roles by regulating OS cell proliferation and migration phenotype. It was demonstrated that NAIF1 would demonstrate important regulative effects and may be a promising therapeutic target of OS.

MiR-216b inhibits osteosarcoma cell proliferation, migration, and invasion by targeting Forkhead Box M1

Osteosarcoma (OS) is considered the most common type of primary malignant bone tumor, which has a high rate of mortality in children and adolescents. However, the current treatment methods for OS are ineffective. Therefore, there is an urgent requirement to identify the critical targets. This study aimed to identify the roles and significance of microRNA-216b (miR-216b) in OS. To explore the cellular and molecular functions of miR-216b and Forkhead Box M1 (FoxM1) in OS, the expression of miR-216b and FoxM1 at the transcriptional level was measured using quantitative real-time PCR (qRT-PCR). Wound healing assay, 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide assay (MTT) assay, flow cytometry, and transwell invasion assay were conducted to study the function of miR-216b and FoxM1 in OS cells. Dual luciferase reporter assay was performed to identify the relationships between miR-216b and FoxM1. qRT-PCR results revealed that miR-216b expression was significantly downregulated, and FoxM1 was observed to be significantly upregulated in human OS cell lines (MG-63) and tissues. MTT data showed that upregulation of miR-216b expression led to cell growth inhibition in MG-63 cells. The results of the invasion assay and wound healing assay illustrated that miR-216b upregulation or FoxM1 downregulation could inhibit the invasion and migration in MG-63 cells. In vivo, the tumor volume was significantly decreased by miR-194 mimic treatment compared with the control group. Furthermore, the results of the luciferase assay indicated that FoxM1 is a direct target of miR-216b. These findings may provide novel insights into the molecular mechanism of miR-216b and FoxM1 in the progression of OS, and suggested that miR-216b may serve as a potential tumor inhibitor of OS by targeting FoxM1.

N-cadherin in cancer metastasis, its emerging role in haematological malignancies and potential as a therapeutic target in cancer

In many types of solid tumours, the aberrant expression of the cell adhesion molecule N-cadherin is a hallmark of epithelial-to-mesenchymal transition, resulting in the acquisition of an aggressive tumour phenotype. This transition endows tumour cells with the capacity to escape from the confines of the primary tumour and metastasise to secondary sites. In this review, we will discuss how N-cadherin actively promotes the metastatic behaviour of tumour cells, including its involvement in critical signalling pathways which mediate these events. In addition, we will explore the emerging role of N-cadherin in haematological malignancies, including bone marrow homing and microenvironmental protection to anti-cancer agents. Finally, we will discuss the evidence that N-cadherin may be a viable therapeutic target to inhibit cancer metastasis and increase tumour cell sensitivity to existing anti-cancer therapies.

MicroRNA-194 regulates cell viability and apoptosis by targeting CDH2 in prostatic cancer

Introduction

Prostate cancer (PCa) is one of the most common malignancies in men. However, a lack of understanding of the mechanism underlying PCa metastasis has strongly limited the effectiveness of therapy for this disease. Thus, investigating the mechanism of PCa may help improve the prognosis of PCa patients. The goal of this study was to investigate the role of microRNA-194 (miR-194) in PCa.

Materials and methods

The expression of miR-194 and cadherin 2 (CDH2) at the transcriptional level was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The MTT assay cell apoptosis assay and Western blotting were used to determine the role of miR-194 and CDH2 in the PC3 human PCa cell line. The dual luciferase reporter assay system was performed to clarify the relationship between miR-194 and CDH2. qRT-PCR results showed that miR-194 was downregulated and CDH2 was upregulated in PC3 cells.

Results

Transfection with miR-194 mimics decreased cell viability and increased the rate of apoptosis compared with the control group of PC3 cells. Bioinformatics and the luciferase reporter assay indicated that CDH2 was a target of miR-194, and Western blot analysis suggested that CDH2 was negatively regulated by miR-194. Further studies revealed that the downregulation of CDH2 suppressed cell viability and promoted the apoptosis of PC3 cells and that miR-194 directly targeted CDH2 in PC3 cells. Finally, the in vivo experiments showed that miR-194 mimics suppressed tumor growth and induced apoptosis in a greater proportion of cells by decreasing the expression of CDH2 compared with the control group.

Conclusion

The results of this study showed that miR-194 targeted CDH2 to regulate PCa cell survival in vitro and suppress tumor growth in vivo. These findings suggest that miR-194 may be a useful therapeutic target in PCa.

PM2.5 downregulates miR-194-3p and accelerates apoptosis in cigarette-inflamed bronchial epithelium by targeting death-associated protein kinase 1

Background

Persistent exposure to cigarette smoke or biomass fuels induces oxidative stress and apoptosis in bronchial epithelium, which is one of the most important pathogenic mechanisms of chronic obstructive pulmonary disease (COPD). Fine particulate matter (PM_2.5) is an aggravating risk factor of COPD exacerbation. Animal evidence showed PM_2.5accelerated lung inflammation and oxidative stress in COPD mice, but the mechanism is still not clear. Recently, we found that miR-194-3p is a novel biomarker of both COPD and PM_2.5 exposure, and miR-194 family has been reported to be involved in cell proliferation and apoptosis. Thus, we propose a hypothesis: PM_2.5 can accelerate apoptotic response of airway epithelial cells in COPD and miR-194 is a potential involved regulator.

Materials and methods

Human bronchial epithelial cells (HBEpiCs) were treated with normal media, cigarette smoke solution (CSS) and PM_2.5-CSS for 24 h. miR-194-3p mimics, inhibitors and scrambled controls were non-transfected or pre-transfected into HBEpiCs for 48 h. MircroRNAs and mRNA expression were quantified by qRT-PCR. Protein expression was analyzed by western blotting. Caspase activities, mitochondrial membrane potential and TUNEL-positive cells were detected to analyze apoptosis. Bioinformatics and luciferase analysis were used to identify the predicted binding site of miR-194-3p and potential targets.

Results

In our study, we found that PM_2.5 significantly aggravated apoptosis in cigarette-inflamed HBEpiCs. miR-194-3p was dramatically downregulated in PM_2.5-CSS-treated HBEpiCs. Bioinformatics and luciferase experiments reported that death-associated protein kinase 1 (DAPK1), regulating caspase 3 activities in apoptosis, was directly targeted by miR-194-3p. Inhibition of miR-194-3p increased DAPK1 expression and apoptosis in normal HBEpiCs. Importantly, overexpression of miR-194-3p suppressed apoptosis in PM_2.5-CSS HBEpiCs.

Conclusion

These results suggested that miR-194-3p was a protective regulator involved in apoptosis pathway and a potential therapeutic target for treatment of bronchial epithelial injury aggravation induced by PM_2.5.

CXCL9 promotes prostate cancer progression through inhibition of cytokines from T cells

Chemokines have been demonstrated to serve an important role in a variety of diseases, particularly in tumor progression. There have been numerous studies that have reported that T cells serve major roles in tumor progression. However, the function of CXC motif chemokine ligand 9 (CXCL9) in prostate cancer remains unknown. The present study aimed to investigate the role of CXCL9 in prostate cancer. A prostate cancer mouse model was generated by treating C57/BL‑6 and B6.Cg‑Selplgtm1Fur/J mice with 3,2'‑dimethyl 4‑aminobiphenyl (DMAB). Hematoxylin and eosin staining detected the histopathological alterations of mouse prostate tissues. Immunohistochemistry (IHC) staining determined cell proliferation of the mice. Flow cytometry was used to detect the alterations of T cells in C57+DMAB or CXCL9+DMAB mice. Immunofluorescence revealed that there was positive expression of interleukin‑6 (IL‑6) and transforming growth factor (TGF)‑β in the mouse tissues. The survival rates of C57+DMAB and CXCL9+DMAB mice was analyzed. The association of CXCL9 expression and clinical stages was also evaluated. Results revealed that prostate cancer pathology and cell proliferation in CXCL9+DMAB mice were significantly greater compared with the C57+DMAB mice. Compared with C57+DMAB mice, the number of T cells in peripheral blood and spleen of CXCL9+DMAB mice was significantly reduced. IHC demonstrated that the expression of IL‑6 and TGF‑β was significantly downregulated in the CXCL9+DMAB mice. The survival rate of CXCL9+DMAB mice was significantly decreased compared with the C57+DMAB mice. In addition, reverse transcription‑quantitative polymerase chain reaction analysis demonstrated that CXCL9 mRNA expression in clinical samples was positively associated with clinical pathological stages of prostate cancer. In conclusion, CXCL9 may promote prostate cancer progression via inhibition of cytokines from T cells.

MicroRNA-645 promotes metastasis of osteosarcoma via targeting tumor suppressor NM23 nucleoside diphosphate kinase 2

Osteosarcoma is the most common non-hematological primary bony malignancy in children and young adults with tumor metastasis being a common event at diagnosis. Understanding the pathogenesis of metastatic osteosarcoma may help identify potential therapeutic targets. In this study, we found that the level of microRNA-645 (miR-645) in osteosarcoma tumor tissues was significantly increased compared with their paired non-tumorous tissues, and was associated with histologic grade, TNM staging, lymph metastasis and distant metastasis. Knockdown of miR-645 caused a remarkable inhibition of migration of osteosarcoma U2OS cells. Furthermore, miR-645 inhibited NME2 (nucleoside diphosphate kinase 2) expression through directly binding to its 3' untranslated region. In human osteosarcoma tissues, we also found that NME2 was significantly decreased in tumor tissues, and its level was negatively correlated with miR-645. In addition, silencing NME2 attenuated the decreased cell migration by knockdown of miR-645, suggesting that it was involved in the miR-645 induced cell migration of osteosarcoma cells. Taken together, we found that miR-645 was up-regulated in osteosarcoma tissues and could promote osteosarcoma cell migration through directly inhibiting the tumor suppressor NME2. Our data provide novel insight into the role of miR-645 in osteosarcoma and indicate that miR-645 might be a potential therapeutic target of osteosarcoma.

Regulatory effects of microRNA‑184 on osteosarcoma via the Wnt/β‑catenin signaling pathway

The present study aimed to investigate the role of microRNA (miRNA/miR)‑184 in osteosarcoma growth, development and metastasis, and the effects of miRNA‑184 on the proliferation, invasion and metastasis of osteosarcoma cells and associated mechanisms. In vitro, miR‑184 was transfected into U‑2OS cells and 143B cells. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was used to detect the expression of miR‑184. MTT was utilized to detect cell proliferation. A Transwell assay was applied to detect cell invasiveness. In vivo, an osteosarcoma tibial orthotopic metastatic tumor model was established, and western blotting and RT‑qPCR were used to detect the expression of Wnt and β‑catenin. Following the overexpression of miR‑184, the proliferation and cell invasion ability were significantly increased in U‑2OS and 143B cells. Following inhibition of miR‑184, cell proliferation and cell invasion ability were significantly decreased. In nude mice, tumor volume significantly increased following overexpression of miR‑184, and Wnt and phosphorylated β‑catenin levels were significantly increased. Following miR‑184 inhibition, tumor volume was significantly decreased, and Wnt and phosphorylated β‑catenin levels were significantly decreased. The results of the present study indicated that the Wnt/β‑catenin signaling pathway serves a key function in the mechanism of osteosarcoma. Inhibition of miRNA‑184 may reduce tumor volume of osteosarcoma via regulation of the Wnt/β‑catenin signaling pathway and may provide a novel strategy for the future diagnosis and treatment of osteosarcoma.

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.

Upregulated N-cadherin expression is associated with poor prognosis in epithelial-derived solid tumours: A meta-analysis

BACKGROUND

N-cadherin is an important molecular in epithelial-mesenchymal transition (EMT) and has been reported to be associated with aggressive behaviours of tumours. However, prognostic value of N-cadherin in solid malignancies remains controversially.

MATERIALS AND METHODS

The Pubmed/MELINE and EMBASE databases were used for a comprehensive literature searching. Pooled risk ratio (RR) and hazard ratio (HR) with their corresponding 95% confidence intervals (CIs) were employed to quantify the prognostic role.

RESULTS

Involving 36 studies with 5705 patients were performed to investigate relationships between N-cadherin upregulation and clinicopathological features, survival. Results suggested upregulated N-cadherin was associated with lymph node metastasis (RR = 1.16, 95% CI [1.00, 1.35]), higher histological grade (RR = 1.36, 95%CI [1.14, 1.62]), angiolymphatic invasion (RR = 1.19, 95% CI [1.06, 1.34]) and advanced clinical stage (RR = 1.32, 95% CI [1.06, 1.64]), while upregulated N-cadherin was apt to be associated with distant metastasis (RR = 1.43, 95% CI [0.99, 2.05]). Moreover, N-cadherin was correlated with poor prognosis of 3-year survival (HR = 1.78, 95% CI [1.51, 2.10]), 5-year survival (HR = 1.57, 95% CI [1.17, 2.10]) and overall survival (OS) (HR = 1.32, 95% CI [1.20, 1.44]). Subgroup analyses according to cancer types were also conducted for applying these conclusions to some tumours more properly. No publication bias was found except subgroup analysis of distant metastasis (P = .652 for Begg's test and 0.023 for Egger's test).

CONCLUSIONS

Taken together, upregulation of N-cadherin is associated with more aggressive behaviours of epithelial-derived solid malignancies and can be regarded as a predictor of poor survival.

MicroRNA-874 inhibits cell proliferation and invasion by targeting cyclin-dependent kinase 9 in osteosarcoma

MicroRNAs (miRNAs) perform important roles in the development and progression of human malignancy. miR-874, as a tumor suppressor, is decreased in malignant tumors, including osteosarcoma. However, the potential mechanism of miR-874 in osteosarcoma remains largely unknown. In the present study, a dual-luciferase reporter system supported cyclin-dependent kinase 9 (CDK9) as a direct target gene of miR-874. miR-874 mimics evidently repressed CDK9 expression in osteosarcoma. Furthermore, osteosarcoma tissues and cell lines exhibited increased expression of CDK9, and CDK9 expression levels were inversely correlated (R=−0.725) with that of miR-874 in osteosarcoma tissues. Finally, CDK9 overexpression reversed the potential effect of miR-874 on the proliferation and invasion of osteosarcoma cells. Overall, the results revealed that miR-874, as a tumor suppressor, is involved in osteosarcoma progression and metastasis by targeting CDK9, indicating that the miR-874/CDK9 pathway may serve as a potential therapeutic target for the treatment of osteosarcoma.

MicroRNAs for osteosarcoma in the mouse: a meta-analysis

Osteosarcoma (OS) is the most common primary malignant bone carcinoma with high morbidity that happens mainly in children and young adults. As the key components of gene-regulatory networks, microRNAs (miRNAs) control many critical pathophysiological processes, including initiation and progression of cancers. The objective of this study is to summarize and evaluate the potential of miRNAs as targets for prevention and treatment of OS in mouse models, and to explore the methodological quality of current studies. We searched PubMed, Web of Science, Embase, Wan Fang Database, VIP Database, China Knowledge Resource Integrated Database, and Chinese BioMedical since their beginning date to 10 May 2016. Two reviewers separately screened the controlled studies, which estimate the effects of miRNAs on osteosarcoma in mice. A pair-wise analysis was performed. Thirty six studies with enough randomization were selected and included in the meta-analysis. We found that blocking oncogenic or restoring decreased miRNAs in cancer cells could significantly suppress the progression of OS in vivo, as assessed by tumor volume and tumor weight. This meta-analysis suggests that miRNAs are potential therapeutic targets for OS and correction of the altered expression of miRNAs significantly suppresses the progression of OS in mouse models, however, the overall methodological quality of studies included here was low, and more animal studies with the rigourous design must be carried out before a miRNA-based treatment could be translated from animal studies to clinical trials.

Downregulation of miR-30a is associated with proliferation and invasion via targeting MEF2D in cervical cancer

Accumulating studies have revealed that microRNAs serve crucial roles in cancer development and progression. MicroRNA-30a (miR-30a) has been implicated in various cancer types. However, the role of miR-30a in cervical cancer remains unclear. In the current study, a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay revealed that miR-30a was significantly downregulated in cervical cancer tissues compared with adjacent normal tissues, and in the cervical cancer cell lines HeLa, SiHa and Ca-Ski compared with GH329 normal cervical epithelial cells. A functional assay using miR-30a mimic demonstrated that miR-30a could inhibit the growth and invasion of cervical cancer cells. Additionally, bioinformatics-based prediction and luciferase reporter assays indicated that MEF2D is a direct target of miR-30a. Transfection with miR-30a reduced the mRNA expression and protein levels of MEF2D, as determined using RT-qPCR and western blot analyses. Furthermore, MEF2D expression was negatively correlated with that of miR-30a in cervical cancers. Overall, the present study demonstrated that miR-30a functions as a tumor suppressor by targeting MEF2D in cervical cancer, which may provide the basis for a prognostic biomarker or therapeutic strategy for cervical cancer.

miR-194 inhibits the proliferation, invasion, migration, and enhances the chemosensitivity of non-small cell lung cancer cells by targeting forkhead box A1 protein

Recent studies have implied that miRNAs may play a crucial role in tumor progression and may be involved in the modulation of some drug resistance in cancer cells. Earlier studies have demonstrated that miR-194 was involved in tumor metastasis and drug resistance in non-small cell lung cancer (NSCLC), whereas their expression and roles on NSCLC still need further elucidation. In the current study, we found that miR-194 is decreased in NSCLC samples compared with adjacent non-cancerous lung samples, and low expression of miR-194 predicts poor patient survival. Both in vitro and in vivo experiments showed that ectopic stable expression miR-194 suppressed proliferation, migration, invasion and metastasis and induced apoptosis in NSCLC cells and that this suppression could be reversed by reintroducing forkhead box A1 (FOXA1), a functional target of miR-194. In addition, miR-194 was downregulated in in cisplatin-resisted human NSCLC cell line-A549/DDP and overexpression of miR-194 increases cisplatin sensitivity. These findings suggested that miR-194 inhibits proliferation and metastasis and reverses cisplatin-resistance of NSCLC cells and may be useful as a new potential therapeutic target for NSCLC.

Knockdown of Long Non-Coding RNA NEAT1 Inhibits Proliferation and Invasion and Induces Apoptosis of Osteosarcoma by Inhibiting miR-194 Expression

PURPOSE

Long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) has been implicated as an oncogene in the development and progression of osteosarcoma. This study aims to explore the mechanism of NEAT1 in osteosarcoma.

MATERIALS AND METHODS

Expressions of NEAT1 and miR-194 in osteosarcoma tissues and cells were detected by quantitative real-time PCR. The effects of NEAT1 knockdown or miR-194 overexpression on cell proliferation, invasion, and apoptosis were determined by 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide (MTT) assay, transwell invasive assay, and flow cytometry analysis, respectively. Luciferase reporter assay was performed to observe the possible interaction between NEAT1 and miR-194.

RESULTS

NEAT1 was upregulated and miR-194 was downregulated in osteosarcoma tissues and cells. Knockdown of NEAT1 or overexpression of miR-194 suppressed proliferation and invasion and induced apoptosis of osteosarcoma cells in vitro. Luciferase reporter assay validated that NEAT1 could interact with miR-194 and negatively modulated its expression. Furthermore, inhibition of miR-194 reversed the suppression of proliferation and invasion and the promotion of apoptosis induced by NEAT1 depletion in osteosarcoma cells.

CONCLUSION

Knockdown of NEAT1 suppressed proliferation and invasion and induced apoptosis in osteosarcoma cells by inhibiting miR-194 expression.

Overexpression of miR-194 Reverses HMGA2-driven Signatures in Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of cancer death worldwide with increasing incidence and mortality in developed countries. Oncogenes and microRNAs regulate key signaling pathways in CRC and are known to be deregulated. Oncogenic transcriptional regulator high-mobility group AT-hook 2 (HMGA2) participates in the transformation of several cancers including CRC and exhibits strong correlation with poor prognosis and distal metastasis. Evidence of HMGA2 and its co-regulated miRs contributing to tumor progression remains to be clarified.

METHODS

We performed gene-set enrichment analysis on the expression profiles of 70 CRC patients and revealed HMGA2 correlated genes that are targeted by several miRs including miR-194. To eliminate the oncogenic effects in HMGA2-driven CRC, we re-expressed miR-194 and found that miR-194 functions as a tumor suppressor by reducing cell proliferation and tumor growth in vitro and in vivo.

RESULTS

As a direct upstream inhibitory regulator of miR-194, overexpression of HMGA2 reduced miR-194 expression and biological activity, whereas re-expressing miR-194 in cells with high levels of HMGA2 impaired the effects of HMGA2, compromising cell survival, the epithelial-mesenchymal transition process, and drug resistance.

CONCLUSION

Our findings demonstrate that novel molecular correlations can be discovered by revisiting transcriptome profiles. We uncover that miR-194 is as important as HMGA2, and both coordinately regulate the oncogenesis of CRC with inverted behaviors, revealing alternative molecular therapeutics for CRC patients with high HMGA2 expression.

MicroRNA-613 inhibits the progression of gastric cancer by targeting CDK9

MicroRNAs (miRNAs) play an important role in the development and progression of human malignancy. miR-613, as a tumour suppressor, was reported to decrease in several tumours. However, the expression levels and role of miR-613 in gastric cancer remain unknown. In this study, we found that miR-613 was evidently downregulated in gastric cancer tissue and cell. The functional analysis showed that miR-613 suppressed cell proliferation and migration in gastric cancer. Next, the dual-luciferase reporter system supported CDK9 as a direct target gene of miR-613. miR-613 mimics evidently repressed CDK9 expression in gastric cancer cells. Furthermore, we found that CDK9 in upregulated in gastric cancer and the CDK9 expression levels were inversely correlated with that of miR-613 in gastric cancer tissues. Overall, the results revealed that miR-613, as a tumour suppressor, involves in gastric cancer progression and metastasis by targeting CDK9, implying a novel potential therapeutic target for the treatment of gastric cancer.

Suppressive effect of microRNA-138 on the proliferation and invasion of osteosarcoma cells via targeting SIRT1

MicroRNAs (miRs), a class of small non-coding RNAs, function as key regulators in gene expression through binding to the 3'-untranslated region (UTR) of their target mRNA, which further leads to translational repression or mRNA degradation. Recently, miR-138 has been found to have a tumor suppressive role in a variety of human malignancies. However, the exact role of miR-138 in regulating the malignant phenotypes of osteosarcoma (OS) has remained to be elucidated. In the present study, reverse-transcription PCR analysis showed that the expression of miR-138 was markedly reduced in OS tissues compared to that in matched adjacent non-tumorous tissues. Furthermore, it was also downregulated in several common OS cell lines, when compared with that in a normal human osteoblast cell line. Overexpression of miR-138 suppressed cell proliferation and invasion and led to a significant decrease in the protein expression of sirtuin 1 (SIRT1), which was further identified as a direct target gene of miR-138 in MG63 cells. Moreover, restoration of SIRT1 expression reversed the suppressive effects of miR-138 on MG63 cell proliferation and invasion. Finally, the expression of SIRT1 was found to be significantly upregulated in OS tissues compared to that in matched adjacent tissues, and SIRT1 levels were inversely correlated with the miR-138 levels in OS tissues. Therefore, the present study demonstrated that miR-138 has a role in inhibiting OS cell proliferation and invasion via directly targeting SIRT1, and suggested that the miR-138/SIRT1 axis may become a promising therapeutic target for OS.

Formation of the IGF1R/CAV1/SRC tri-complex antagonizes TRAIL-induced apoptosis in gastric cancer cells

Lipid rafts provide a biological platform for apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). We previously reported that insulin-like growth factor 1 receptor (IGF1R) translocation into lipid rafts helped to explain TRAIL resistance. However, it was not clear whether TRAIL resistance was caused by the interaction of IGF1R with caveolin-1 (CAV1) and the non-receptor tyrosine kinase SRC in lipid rafts of gastric cancer cells. Here, we observed high IGF1R expression in TRAIL-resistant gastric cancer cells, and showed that IGF1R combined with both CAV1 and SRC in a native complex. TRAIL was shown to promote the formation of the IGF1R/CAV1/SRC tri-complex and the activation of these three molecules. Knockdown of IGF1R or CAV1 or inhibition of SRC activity reduced the formation of this tri-complex and enhanced TRAIL-induced apoptosis. Furthermore, the overexpression of microRNA-194 reversed TRAIL resistance by reducing IGF1R expression. In summary, TRAIL increased formation of the IGF1R/CAV1/SRC tri-complex and the activation of downstream survival pathways, leading to TRAIL resistance in gastric cancer cells.

Dysregulation of the miR-194-CUL4B negative feedback loop drives tumorigenesis in non-small-cell lung carcinoma

Cullin 4B (CUL4B), a scaffold protein that assembles CRL4B ubiquitin ligase complexes, is overexpressed in many types of cancers and represses many tumor suppressors through epigenetic mechanisms. However, the mechanisms by which CUL4B is upregulated remain to be elucidated. Here, we show that CUL4B is upregulated in non‐small‐cell lung carcinoma (NSCLC) tissues and is critically required for cell proliferation and migration in vitro and for xenograft tumor formation in vivo. We found that microRNA‐194 (miR‐194) and CUL4B protein were inversely correlated in cancer specimens and demonstrated that miR‐194 could downregulate CUL4B by directly targeting its 3′‐UTR. We also showed that CUL4B could be negatively regulated by p53 in a miR‐194‐dependent manner. miR‐194 was further shown to attenuate the malignant phenotype of lung cancer cells by downregulating CUL4B. Interestingly, CRL4B also epigenetically represses miR‐194 by catalyzing monoubiquitination at H2AK119 and by coordinating with PRC2 to promote trimethylation at H3K27 at the gene clusters encoding miR‐194. RBX1, another component in CRL4B complex, is also targeted by miR‐194 in NSCLC cells. Our results thus establish a double‐negative feedback loop between miR‐194 and CRL4B, dysregulation of which contributes to tumorigenesis. The function of miR‐194 as a negative regulator of CUL4B has therapeutic implications in lung cancer.

miR-194-5p/BCLAF1 deregulation in AML tumorigenesis

Deregulation of epigenetic mechanisms, including microRNA, contributes to leukemogenesis and drug resistance by interfering with cancer-specific molecular pathways. Here, we show that the balance between miR-194-5p and its newly discovered target BCL2-associated transcription factor 1 (BCLAF1) regulates differentiation and survival of normal hematopoietic progenitors. In acute myeloid leukemias this balance is perturbed, locking cells into an immature, potentially ‘immortal’ state. Enhanced expression of miR-194-5p by treatment with the histone deacetylase inhibitor SAHA or by exogenous miR-194-5p expression re-sensitizes cells to differentiation and apoptosis by inducing BCLAF1 to shuttle between nucleus and cytosol. miR-194-5p/BCLAF1 balance was found commonly deregulated in 60 primary acute myeloid leukemia patients and was largely restored by ex vivo SAHA treatment. Our findings link treatment responsiveness to re-instatement of miR-194-5p/BCLAF1 balance.

MicroRNA-194 Promotes Prostate Cancer Metastasis by Inhibiting SOCS2

Serum levels of miR-194 have been reported to predict prostate cancer recurrence after surgery, but its functional contributions to this disease have not been studied. Herein, it is demonstrated that miR-194 is a driver of prostate cancer metastasis. Prostate tissue levels of miR-194 were associated with disease aggressiveness and poor outcome. Ectopic delivery of miR-194 stimulated migration, invasion, and epithelial-mesenchymal transition in human prostate cancer cell lines, and stable overexpression of miR-194 enhanced metastasis of intravenous and intraprostatic tumor xenografts. Conversely, inhibition of miR-194 activity suppressed the invasive capacity of prostate cancer cell lines in vitro and in vivo Mechanistic investigations identified the ubiquitin ligase suppressor of cytokine signaling 2 (SOCS2) as a direct, biologically relevant target of miR-194 in prostate cancer. Low levels of SOCS2 correlated strongly with disease recurrence and metastasis in clinical specimens. SOCS2 downregulation recapitulated miR-194-driven metastatic phenotypes, whereas overexpression of a nontargetable SOCS2 reduced miR-194-stimulated invasion. Targeting of SOCS2 by miR-194 resulted in derepression of the oncogenic kinases FLT3 and JAK2, leading to enhanced ERK and STAT3 signaling. Pharmacologic inhibition of ERK and JAK/STAT pathways reversed miR-194-driven phenotypes. The GATA2 transcription factor was identified as an upstream regulator of miR-194, consistent with a strong concordance between GATA2 and miR-194 levels in clinical specimens. Overall, these results offer new insights into the molecular mechanisms of metastatic progression in prostate cancer. Cancer Res; 77(4); 1021-34. ©2016 AACR.

MicroRNA-194 suppresses prostate cancer migration and invasion by downregulating human nuclear distribution protein

Human NudC nuclear distribution protein (hNUDC) is differentially expressed between normal and cancer cells. Based on its marked altered expression and its roles in modulating cell division, cytokineses and migration, a detailed understanding of the mechanisms regulating hNUDC expression in cancer cells is critical. In this study, we identified miR-194 as a downstream target of hNUDC and linked its expression to reduced metastatic capacity and tumorigenicity of prostate cancer (PCa) cells. Using miRNA target prediction programs, hNUDC mRNA was found to contain a potential binding site for miR-194 within its 3'UTR. A Reporter assay confirmed that post-transcriptional regulation of hNUDC was dependent on the miR-194 binding site. Forced expression of miR-194 in PCa cell lines, PC-3 and DU-145, led to a decrease in the mRNA and protein levels of hNUDC. Overexpression of miR-194 in these cells inhibited cell migration and invasion, and induced multinucleated cells. Our data showed that hNUDC knockdown by siRNA significantly reduced the migration and invasion in the PC-3 and DU-145 cells, phenocopying the results of miR-194 overexpression. Furthermore, lentivirus-mediated stable expression of miR-194 in PCa cells reduced the ability of colony formation as detected by a soft agar assay and exhibited significantly less tumorigenic ability in vivo. Our results suggest a novel role for miR-194 in effectively controlling cell metastatic processes in PCa cells via the regulation of hNUDC expression.

Identification of microRNA profiles associated with refractory primary biliary cirrhosis

MicroRNAs (miRNAs) are small, endogenous, non-coding RNAs that control the target gene translation by RNA interference; miRNAs are associated with cellular processes, including proliferation, differentiation, apoptosis, and cell survival. Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease of unknown etiology. One third of patients with PBC demonstrate suboptimal responses, which result in worse outcomes. It has been previously reported that miRNAs are involved in drug resistance, however, the association between miRNA expression levels and refractory PBC remains to be fully elucidated. In the present study, among the 20 patients with PBC treated with ursodeoxycholic acid or bezafibrate, 15 patients were classed as treatment‑effective, and 5 were classed as being treatment‑resistant. Using the miRNA array technique, miRNA profiles were identified for each group. A total of 35 miRNAs were significantly upregulated, and 23 were significantly downregulated in the treatment‑resistant group compared with the treatment‑effective group. In order to examine the association between the highly altered miRNAs and clinical features of the two groups, numerous parameters were analyzed. Elevated levels of direct bilirubin, aspartate transaminase (AST), and alanine transaminase (ALT) were identified to be associated with miRNA‑122 upregulation. AST, ALT, and γ guanosine triphosphate were additionally associated with miRNA‑378f upregulation. However, the reduction of miRNA‑4311 was associated with reduced levels of AST and ALT. miRNA‑4714‑3p was also negatively correlated with total bilirubin and lactate dehydrogenase. Therefore, identifying the miRNA profile was demonstrated to be a useful approach in the characterization of PBC development. It is suggested that highly altered miRNAs may be potential biomarkers for use in the development of treatment of patients with refractory PBC.

Involvement and Clinical Aspects of MicroRNA in Osteosarcoma

Osteosarcoma (OS) is the most common primary bone cancer in children and adolescents, but its pathogenesis has been difficult to establish because of its well-known heterogeneous nature. OS has been associated with genetic and cytogenetic abnormalities, which include function-impairing mutations in tumor suppressors and the activation of oncogenes. OS tumorigenesis has been linked to alterations of several genes characterized by a high level of genetic instability and recurrent DNA amplifications and deletions. MicroRNAs (miRNAs), 18–25-nucleotide noncoding RNAs, are critical for various biological processes like differentiation, cell growth and cell death. Dysregulation of miRNA expression leads to phenotypic and genotypic changes in cells, which leads to cancer. Studies on miRNAs have initiated a significant effect in both diagnosis and treatment of cancer. This review focuses on the current knowledge of clinical applications of miRNAs for the better diagnosis and management of OS.

MicroRNA-200b acts as a tumor suppressor in osteosarcoma via targeting ZEB1

Osteosarcoma is the most common type of cancer that develops in bone, mainly arising from the metaphysis of the long bones. MicroRNA (miR)-200b has been found to generally act as a tumor suppressor in multiple types of human cancers. However, the detailed role of miR-200b in osteosarcoma still remains to be fully understood. This study aimed to investigate the exact role of miR-200b in the progression of osteosarcoma and the underlying mechanism. Real-time reverse transcription-polymerase chain reaction data showed that miR-200b was significantly downregulated in osteosarcoma tissues compared to their matched adjacent nontumor tissues. Low miR-200b level was associated with the advanced clinical stage and positive distant metastasis. Besides, it was also downregulated in osteosarcoma cell lines (U2OS, Saos2, HOS, and MG63) compared to normal osteoblast cell line NHOst. In vitro study showed that restoration of miR-200b led to a significant decrease in proliferation, migration, and invasion of osteosarcoma cells. Moreover, ZEB1 was identified as a target gene of miR-200b, and its expression levels were negatively mediated by miR-200b in osteosarcoma cells. In addition, ZEB1 was significantly upregulated in osteosarcoma cells compared to the normal osteoblast cell line NHOst, and inhibition of ZEB1 expression also suppressed the proliferation, migration, and invasion in osteosarcoma cells. Finally, we showed that ZEB1 was frequently upregulated in osteosarcoma tissues compared to their matched adjacent normal tissues, and its expression was reversely correlated to the miR-200b levels in osteosarcoma tissues. Based on these findings, our study suggests that miR-200b inhibits the proliferation, migration, and invasion of osteosarcoma cells, probably via the inhibition of ZEB1 expression. Therefore, miR-200b/ZEB1 may become a potential target for the treatment of osteosarcoma.

Phenethyl isothiocyanate (PEITC) suppresses prostate cancer cell invasion epigenetically through regulating microRNA-194

SCOPE

Tumor metastasis greatly contributes to the mortality of prostate cancer. The glucosinolate-derived phenethyl isothiocyanate (PEITC) has been widely documented to reduce the risk of prostate cancer by modulating multiple biologically relevant processes. Emerging evidence suggests that PEITC may exert its anti-cancer effects through epigenetic mechanisms including microRNAs. Altered levels of miRNA have been linked to tumor malignancy due to their capacity to regulate functional gene expression in carcinogenesis. Here, we assessed the effects of PEITC on miRNA expression which is related to PCa cell invasiveness.

METHODS AND RESULTS

Utilizing oligonucleotide microarray first identified the most affected miRNAs in LNCaP cells after PEITC treatment. Several top altered miRNAs were further validated using quantitative PCR. Interestingly, overexpression of miR-194 suppressed PC3 cell invasion in matrigel-coated Transwell chambers. Bone morphogenetic protein 1 (BMP1) was shown to be a direct target of miR-194. Downregulation of BMP1 by miR-194 or PEITC led to decreased expression of key oncogenic matrix metalloproteinases, MMP2 and MMP9. This in turn resulted in the suppression of tumor invasion.

CONCLUSION

Our results indicate that miR-194 downregulates the expression of oncogenic MMP2 and MMP9 by targeting BMP1, which suggests a potential new mechanistic target by which PEITC suppresses prostate cancer cell invasiveness.

Genetic factors conferring metastasis in osteosarcoma

Osteosarcoma (OS) is a deadly bone malignancy affecting mostly children and adolescents. OS has outstandingly complex genetic alterations likely due to p53-independent genomic instability. Based on analysis of recent published research we claim existence of various genetic mechanisms of osteosarcomagenesis conferring great variability to different OS properties including metastatic potential. We also propose a model explaining how diverse genetic mechanisms occur and providing a framework for future research. P53-independent preexisting genomic instability, which precedes and frequently causes TP53 genetic alterations, is central in our model. In addition, our analyses reveal a possible cooperation between aberrantly activated HIF-1α and AP-1 genetic pathways in OS metastasis. We also review the involvement of noncoding RNA genes in OS metastasis.