miRNAs In Osteosarcoma Research Articles

MicroRNA signatures in osteosarcoma: diagnostic insights and therapeutic prospects.

Osteosarcoma (OSa) is the most prevalent primary malignant bone tumor in children and adolescents, characterized by complex genetic and epigenetic alterations. Traditional treatments face significant challenges due to high rates of drug resistance and lack of targeted therapies. Recent advances in microRNA (miRNA) research have opened new avenues for understanding and treating osteosarcoma. This review explores the many critical functions of miRNAs in osteosarcoma, particularly their potential for clinical use. The review highlights two key areas where miRNAs could be beneficial. Firstly, miRNAs can act as biomarkers for diagnosing osteosarcoma and predicting patient prognosis. Secondly, specific miRNAs can regulate cellular processes like proliferation, cell death, migration, and even resistance to chemotherapy drugs in osteosarcoma. This ability to target multiple pathways within cancer cells makes miRNA-based therapies highly promising. Additionally, though the interaction between miRNAs and circular RNAs (circRNAs) falls outside the scope of the paper, it has also been discussed briefly. While miRNA-based therapies offer exciting possibilities for targeting multiple pathways in osteosarcoma, challenges remain. Efficient delivery, potential off-target effects, tumor complexity, and rigorous testing are hurdles to overcome before these therapies can reach patients. Despite these challenges, continued research and collaboration among scientists, clinicians, and regulatory bodies hold the promise of overcoming them. This collaborative effort can pave the way for the development of safe and effective miRNA-based treatments for osteosarcoma.

Exosomal MiRNAs in Osteosarcoma: Biogenesis and Biological Functions.

MiRNAs are a group of non-coding RNA molecules that function in mRNA translational inhibition via base-pairing with complementary sequences in target mRNA. In oncology, miRNAs have raised great attention due to their aberrant expression and pivotal roles in the pathogenesis of multiple malignancies including osteosarcoma. MiRNAs can be transported by exosome, the nano-extracellular vesicle with a diameter of 30–150 nm. Recently, a growing number of studies have demonstrated that exosomal miRNAs play a critical role in tumor initiation and progression, by exerting multiple biological functions including metastasis, angiogenesis, drug resistance and immunosuppression. In this review, we aim to depict the biogenesis of exosomal miRNAs and summarize the potential diagnostic and therapeutic functions of exosomal miRNAs in osteosarcoma.

CircRNA_0078767 promotes osteosarcoma progression by increasing CDK14 expression through sponging microRNA-330-3p

Circular RNA (circRNA)-associated competing endogenous RNA (ceRNA) mechanism have emerged as critical mechanism in cancer initiation and progression. However, the roles of the circRNA-microRNA (miRNA)-messenger RNA ceRNA network in osteosarcoma are still not fully characterized. In this study, therefore, circ_0078767-related ceRNA mechanism in osteosarcoma was studied. Bioinformatics tools primarily identified differentially expressed circRNAs and their downstream miRNAs in osteosarcoma, implying the potential interaction between circ_0078767, miR-330-3p, and cyclin-dependent kinase 14 (CDK14) in this malignancy, which were further verified by means of RNA immunoprecipitation, RNA pull-down, and dual-luciferase reporter gene assays. Aberrant abundance of circ_0078767 was found in both osteosarcoma tissues and cells, relating to dismal prognosis in patients with osteosarcoma. Functionally, circ0078767 strengthened the proliferation, invasiveness, and migration of osteosarcoma cells, which could be neutralized by miR-330-3p. Additionally, miR-330-3p targeted and decreased CDK14 expression whereby motivating the malignant phenotypes of osteosarcoma cells. Through in vivo experiments, we further confirmed that circ_0078767 targeted miR-330-3p to upregulate CDK14, whereby strengthening the in vivo tumorigenic and metastatic ability of osteosarcoma cells. Circ_0078767 promotes the occurrence and development of osteosarcoma by upregulating CDK14 in a miR-330-3p-dependent manner.

MiR-486-5p expression is regulated by DNA methylation in osteosarcoma

BackgroundOsteosarcoma is the most common primary malignant tumour of bone occurring in children and young adolescents and is characterised by complex genetic and epigenetic changes. The miRNA miR-486-5p has been shown to be downregulated in osteosarcoma and in cancer in general.ResultsTo investigate if the mir-486 locus is epigenetically regulated, we integrated DNA methylation and miR-486-5p expression data using cohorts of osteosarcoma cell lines and patient samples. A CpG island in the promoter of the ANK1 host gene of mir-486 was shown to be highly methylated in osteosarcoma cell lines as determined by methylation-specific PCR and direct bisulfite sequencing. High methylation levels were seen for osteosarcoma patient samples, xenografts and cell lines based on quantitative methylation-specific PCR. 5-Aza-2′-deoxycytidine treatment of osteosarcoma cell lines caused induction of miR-486-5p and ANK1, indicating common epigenetic regulation in osteosarcoma cell lines. When overexpressed, miR-486-5p affected cell morphology.ConclusionsmiR-486-5p represents a highly cancer relevant, epigenetically regulated miRNA in osteosarcoma, and this knowledge contributes to the understanding of osteosarcoma biology.

Potential Anti-Metastatic Role of the Novel miR-CT3 in Tumor Angiogenesis and Osteosarcoma Invasion.

Osteosarcoma (OS) is the most common primary bone tumor mainly occurring in young adults and derived from primitive bone-forming mesenchyme. OS develops in an intricate tumor microenvironment (TME) where cellular function regulated by microRNAs (miRNAs) may affect communication between OS cells and the surrounding TME. Therefore, miRNAs are considered potential therapeutic targets in cancer and one of the goals of research is to accurately define a specific signature of a miRNAs, which could reflect the phenotype of a particular tumor, such as OS. Through NGS approach, we previously found a specific molecular profile of miRNAs in OS and discovered 8 novel miRNAs. Among these, we deepen our knowledge on the fifth candidate renamed now miR-CT3. MiR-CT3 expression was low in OS cells when compared with human primary osteoblasts and healthy bone. Through TargetScan, VEGF-A was predicted as a potential biological target of miR-CT3 and luciferase assay confirmed it. We showed that enforced expression of miR-CT3 in two OS cell lines, SAOS-2 and MG-63, reduced expression of VEGF-A mRNA and protein, inhibiting tumor angiogenesis. Enforced expression of miR-CT3 also reduced OS cell migration and invasion as confirmed by soft agar colony formation assay. Interestingly, we found that miR-CT3 behaves inducing the activation of p38 MAP kinase pathway and modulating the epithelial-mesenchymal transition (EMT) proteins, in particular reducing Vimentin expression. Overall, our study highlights the novel role of miR-CT3 in regulating tumor angiogenesis and progression in OS cells, linking also to the modulation of EMT proteins.

Research Progress of Exosome-Loaded miRNA in Osteosarcoma.

Currently, although the improvement of surgical techniques and the development of chemotherapy drugs have brought a certain degree of development to the treatment of osteosarcoma, the treatment of osteosarcoma has many shortcomings, and its treatment is limited. MiRNAs and exosomes can be used as diagnostic tools, and they play an important role in the occurrence and chemotherapy resistance of osteosarcoma. Therefore, providing a new method for the treatment of osteosarcoma is the key to solving this problem. To systematically summarize the research status of exoskeleton drug-loaded miRNA in osteosarcoma, we identified and evaluated 208 studies and found that exosome-carrying miRNA can be used as an index for the diagnosis and prognosis of osteosarcoma and share a certain relationship with chemosensitivity. In addition, exosomes can also be used as a carrier of genetic drugs able to regulate the progression of osteosarcoma. Based on the above findings, we propose suggestions for the future development of this field, aiming to bring new ideas for the early diagnosis and treatment of osteosarcoma.

PathVisio Analysis: An Application Targeting the miRNA Network Associated with the p53 Signaling Pathway in Osteosarcoma

MicroRNAs (miRNAs) are small single-stranded, non-coding RNA molecules involved in the pathogenesis and progression of cancer, including osteosarcoma. We aimed to clarify the pathways involving miRNAs using new bioinformatics tools. We applied WikiPathways and PathVisio, two open-source platforms, to analyze miRNAs in osteosarcoma using miRTar and ONCO.IO as integration tools. We found 1298 records of osteosarcoma papers associated with the word “miRNA”. In osteosarcoma patients with good response to chemotherapy, miR-92a, miR- 99b, miR-193a-5p, and miR-422a expression is increased, while miR-132 is decreased. All identified miRNAs seem to be centered on the TP53 network. This is the first application of PathVisio to determine miRNA pathways in osteosarcoma. MiRNAs have the potential to become a useful diagnostic and prognostic tool in the management of osteosarcoma. PathVisio is a full pathway editor with the potentiality to illustrate the biological events, augment graphical elements, and elucidate all the physical structures and interactions with standard external database identifiers.

Identification of potential micro-messenger RNAs (miRNA–mRNA) interaction network of osteosarcoma

ABSTRACT Osteosarcoma (OS) is the most common primary malignant tumor in children and adolescents. Numerous studies have reported the importance of miRNA in OS. The purpose of this study is to predict potential biomarkers and new therapeutic targets for OS diagnosis and prognosis by analyzing miRNAs of OS plasma samples from the Gene Expression Omnibus (GEO) database. Data-sets were downloaded from the GEO and analyzed using R software. Different expressions of miRNAs (DE-miRNAs) in plasma and mRNAs (DE-mRNAs) in OS patients were identified. Funrich was used to predict the transcription factors and target genes of miRNAs. By comparing the target mRNAs and DE-mRNAs, the intersection mRNAs were identified. The intersection mRNAs were imported to perform Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. MiRNA-mRNA regulatory network and a protein-protein interaction (PPI) network were constructed by using Cytoscape. Finally, a total of 164 DE-miRNAs, 256 DE-mRNAs, and 76 intersection mRNAs were identified. The top 10 TF of up- and down-regulated DE-miRNAs were also predicted. In addition, GO and KEGG analyses further revealed the intersection mRNAs. By constructing the miRNA–mRNA networks, we found miR-30d-5p, miR-17-5p, miR-98-5p, miR-301a-3p, and miR-30e-5p were the central hubs. COL1A1, COL1A2, MMP2, CDH11, COL4A1 etc. were predicted to be the key mRNA by constructing the PPI networks. Through a comprehensive bioinformatics analysis of miRNAs and mRNAs in OS, we explored the potential effective biomarkers and novel therapeutic targets for the diagnosis and prognosis of OS.

MicroRNA-652 promotes cell proliferation and osteosarcoma invasion by directly targeting KLF9.

Previous studies have demonstrated that various microRNAs (miRNAs or miRs) are abnormally expressed in osteosarcoma (OS) and serve roles in its malignant development. An in-depth understanding of the specific roles of dysregulated miRNAs in OS may be important for cancer research and the identification of novel therapeutic targets. In the current study, reverse transcription-quantitative PCR was performed to determine miR-652 expression in OS tissues and cell lines. Cell Counting Kit-8 and Transwell invasion assays were used for assessing the effect of miR-652 on the proliferation and invasion of OS cells. Herein, miR-652 expression was assessed in OS and the effects and molecular mechanisms of miR-652 in OS cells were examined. The results revealed that miR-652 expression was significantly upregulated in OS tissues and cell lines compared with adjacent normal tissues and a normal human osteoblast cell line. Furthermore, miR-652 downregulation inhibited the proliferation and invasion of OS cells. miR-652 was also demonstrated to directly interact with the 3'-untranslated region of kruppel-like factor 9 (KLF9) and miR-652 negatively regulated KLF9 expression in OS cells. miR-652 and KLF9 mRNA levels were also revealed to be inversely correlated in OS tissues. Treatment with KLF9 small interfering RNA abolished the suppression of OS proliferation and invasion induced by miR-652 downregulation. miR-652 may serve an oncogenic role in OS cells by targeting KLF9 directly. The results also indicated that miR-652 may be an effective novel therapeutic target for the treatment of patients with OS.

MiR-874-3p inhibits cell migration through targeting RGS4 in osteosarcoma.

The present study explored the role and mechanism of microRNA-874-3p (miR-874-3p) in the migration of the osteosarcoma cell line, U-2 OS. The expression profile of osteosarcoma (OS) microRNA (GSE65071) datasets was downloaded from the Gene Expression Omnibus (GEO) database (https://www.ncbi.nlm.nih.gov/geo) to identify differentially expressed miRNAs in OS and its biological functions. A quantitative reverse transcription-polymerase chain reaction was performed to detect the expression of miR-874-3p and its target gene regulator of G protein 4 (RGS4) in human osteosarcoma cells U-2 OS and normal osteoblast hFOB1.19. Plasmid overexpression miR-874-3p and pcDNA-RGS4 were transfected into U-2 OS using Lipofectamine 2000 (Thermo Fisher, Waltham, MA, USA). Cell migration was measured using Transwell migration assays. Bioinformatic analysis and luciferase reporter assay were conducted to search for the target gene of miR-874-3p. In total, 167 differentially expressed miRNAs were detected after the analysis of GSE65071; of which 78 were up-regulated genes and 89 were down-regulated. miR-874-3p was down-regulated and selected for further analysis. The expression level of miR-874-3p in U-2 OS cells was significantly decreased compared to the hFOB1.19 cell line (p < 0.05). Overexpression of miR-874-3p significantly inhibited the proliferation and migration of U-2 OS cells and overexpression of RGS4 reversed the inhibitory effect of miR-874-3p on U-2 OS cells. Through luciferase report analyses and bioinformatic analysis, RGS4 may be the candidate target gene of miR-874-3p. In conclusion, overexpression of miR-874-3p suppressed OS cell proliferation and migration. Thus, miR-874-3p might present a therapeutic agent for the treatment of OS.

MiR-487a performs oncogenic functions in osteosarcoma by targeting BTG2 mRNA.

Aberrant microRNA (miRNA) expression plays a critical role in osteosarcoma (OS) pathogenesis. In this study, we elucidated the involvement of miR-487a in OS and the underlying molecular mechanisms. We found that miR-487a was upregulated in OS clinical samples and cell lines. Knockdown of miR-487a suppressed OS cell growth and invasion and induced apoptosis; however, overexpression of miR-487a promoted OS cell growth and invasion. Accordingly, downregulation of miR-487a significantly suppressed tumor growth of OS xenografts in vivo. Furthermore, B-cell translocation gene 2 (BTG2) mRNA was found to be a novel target of miR-487a. Knockdown of BTG2 using small interfering RNA (siRNA) recapitulated the oncogenic effects of miR-487a, whereas BTG2 overexpression partially reversed these effects. Finally, miR-487a levels were found to be negatively correlated with BTG2 expression in OS clinical samples. Collectively, our data suggest that miR-487a is an oncogenic miRNA in OS and it lowers BTG2 expression.

Role of miRNA‐542‐5p in the tumorigenesis of osteosarcoma

Osteosarcoma, one of the most common malignant bone tumors, is characterized by a high rate of metastasis, and the survival rate of patients with metastatic osteosarcoma is poor. Previous studies have reported that miRNAs often regulate the occurrence and development of various tumors. In this work, we identified miRNA‐542‐5p as a critical miRNA in osteosarcoma by overlapping three Gene Expression Omnibus datasets, and then evaluated miRNA‐542‐5p expression profiles using Gene Expression Omnibus and Sarcoma‐microRNA Expression Database. We used MISIM to investigate miRNAs correlated with miR‐542 and identified potential target genes of miRNA‐542‐5p using miRWalk. Functional and pathway enrichment analyses were performed using The Database for Annotation, Visualization and Integrated Discovery. Protein–protein interaction was performed using Search Tool for the Retrieval of Interacting Genes and Cytoscape. We report that the relative level of miRNA‐542‐5p was significantly higher in osteosarcoma than in healthy bone. Expressions of hsa‐miR‐330 and hsa‐miR‐1202 were found to be strongly correlated with that of miR‐542‐5p. Furthermore, we identified a total of 514 down‐regulated genes as possible targets of miR‐542‐5p. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis demonstrated that the putative target genes of miR‐542‐5p were most enriched in the cell‐cycle process. The differentially expressed genes CDCA5, PARP12 and HSPD1 were found to be hub genes in protein–protein interaction networks. Finally, transfection of the osteosarcoma cell line U2OS with miR‐542‐5p mimics or inhibitor revealed that miR‐542‐5p can promote cell proliferation. In conclusion, our results suggest that miR‐542‐5p may promote osteosarcoma proliferation; thus, this miRNA may have potential as a biomarker for diagnosis and prognosis.

Identification of aberrantly methylated differentially expressed genes targeted by differentially expressed miRNA in osteosarcoma.

BackgroundOsteosarcoma (OS) is the most common primary bone tumors diagnosed in children and adolescents. Recent studies have shown a prognostic role of DNA methylation in various cancers, including OS. The aim of this study was to identify the aberrantly methylated genes that are prognostically relevant in OS.MethodsThe differentially expressed mRNAs, miRNAs and methylated genes (DEGs, DEMs and DMGs respectively) were screened from various GEO databases, and the potential target genes of the DEMs were predicted by the RNA22 program. The protein-protein interaction (PPI) networks were constructed using the STRING database and visualized by Cytoscape software. The functional enrichment and survival analyses of the screened genes was performed using the R software.ResultsForty-seven downregulated hypermethylated genes and three upregulated hypomethylated genes were identified that were enriched in cell activation, migration and proliferation functions, and were involved in cancer-related pathways like JAK-STAT and PI3K-AKT. Eight downregulated hypermethylated tumor suppressor genes (TSGs) were identified among the screened genes based on the TSGene database. These hub genes are likely involved in OS genesis, progression and metastasis, and are potential prognostic biomarkers and therapeutic targets.ConclusionsTSGs including PYCARD, STAT5A, CXCL12 and CXCL14 were aberrantly methylated in OS, and are potential prognostic biomarkers and therapeutic targets. Our findings provide new insights into the role of methylation in OS progression.

The Role of miRNA in the Diagnosis, Prognosis, and Treatment of Osteosarcoma.

Osteosarcoma (OS) is one of the most common malignant tumors derived from mesenchymal tissue and is highly invasive, mainly in children and adolescents. Treatment of OS is mostly based on standard treatment options, including aggressive surgical resection, systemic chemotherapy, and targeted radiation therapy, but the 5-year survival rate is still low. MicroRNA (miRNA) is a highly conserved type of endogenous nonprotein-encoding RNA, about 19-25 nucleotides in length, whose transcription process is independent of other genes. Generally, miRNAs play a role in regulating cell proliferation, differentiation, apoptosis, and development by binding to the 3' untranslated region of target mRNAs, whereby they can degrade or induce translational silencing. Although miRNAs play a regulatory role in various metabolic processes, they are not translated into proteins. Several studies have shown that miRNAs play an important role in the diagnosis, treatment, and prognosis of OS. Herein, the authors describe new advances in the diagnosis, prognosis, and treatment of miRNAs in OS.

Identification and validation of microRNAs and their targets expressed in osteosarcoma

Osteosarcoma (OS) is the most common type of bone cancer in children and adolescents, and has a poor prognosis. Previous studies have demonstrated that a number of microRNAs (miRNAs) were deregulated in OS, and that the expression of certain miRNAs was correlated with the stage of OS. Therefore, miRNAs may serve a role as a diagnostic and prognostic biomarker of OS. miRNA and mRNA integrated analysis of public expression profiles in the Gene Expression Omnibus database for OS was performed, and the regulated targets of miRNA in OS were predicted. Next, the regulatory network of miRNAs/genes was constructed and verified by reverse transcription-quantitative polymerase chain reaction in tissues and MG-63 cell lines. Two miRNA expression profiling studies and four eligible mRNA expression profiling studies were selected. Ten upregulated miRNAs, 5 downregulated miRNAs and 5 DGEs were identified in OS compared with normal tissues. hsa-miR-346 was inversely correlated with the target gene c-FLIP, which was consistent with the results of integrated analysis. In vitro, pre-miRNA-346 can downregulate the protein expression of c-FLIP, while not changing the mRNA level of c-FLIP. In the regulatory network, hsa-miR-346 and its target gene, c-FLIP, can be used as biomarkers for an earlier diagnosis of OS.

MicroRNA‑873 targets HOXA9 to inhibit the aggressive phenotype of osteosarcoma by deactivating the Wnt/β‑catenin pathway.

Several microRNAs (miRNAs or miRs) that regulate a variety of cancer‑related events are dysregulated in osteosarcoma(OS). An exploration of the specific roles of miRNAs in OS is crucial for the identification of suitable therapeutic targets. Previous studies have shown that miR‑873 plays tumor suppressive or oncogenic roles in different types of cancer. However, whether miR‑873 is implicated in OS carcinogenesis and cancer progression remains poorly understood. In the present study, we demonstrated that the miR‑873 levels were decreased in OStissues and cell lines. The decreased expression of miR‑873 was related to tumor size, clinical stage and distant metastasis in patients with OS. The introduction of miR‑873 significantly inhibited tumor cell proliferation, migration and invasion invitro, promoted apoptosis invitro and restricted tumor growth invivo. Furthermore, homeoboxA9 (HOXA9) was validated as a direct target gene of miR‑873 in OS cells. HOXA9 was markedly expressed in OStissues, and its upregulation inversely correlated with the miR‑873 levels. Moreover, HOXA9 silencing produced similar effects as observed with miR‑873 overexpression in OS cells. Consistently, the exogenous expression of HOXA9 partially reversed the suppression of the aggressive phenotype induced by miR‑873 overexpression in OS cells. Notably, miR‑873 was able to deactivate the Wnt/β‑catenin pathway in OS cells by regulating HOXA9, both invitro and invivo. On the whole, the present study demonstrates that miR‑873 suppresses the development of OS by directly targeting HOXA9 and inhibiting the Wnt/β‑catenin pathway, and suggests that miR‑873 may prove to be useful as a diagnostic biomarker of OS, as well as in the development of novel therapies.

MicroRNA-221 regulates osteosarcoma cell proliferation, apoptosis, migration, and invasion by targeting CDKN1B/p27.

MicroRNAs (miRNAs, miR) are of critical importance in growth and metastasis of cancer cells; however, the underlying functions of miRNAs in osteosarcoma (OS) remain largely unknown. This study was aimed to elucidate the role of miR-221 in regulating the biological behavior of OS cells. The proliferation ability was examined by cell counting kit-8 (CCK-8) and cell cycle assay. The abilities of cell migration, invasion, and apoptosis were monitored by transwell assay and flow cytometry, respectively. The effect of miR-221 on cyclin-dependent kinase inhibitor 1B (CDKN1B) expression was evaluated by luciferase assays, real-time polymerase chain reaction, and Western blot analysis. We found that miR-221 was elevated in OS cell lines compared with the normal osteoblastic cell line. Transfection of the miR-221 inhibitor into MG63 and U-2OS cell lines obviously suppressed cell proliferation, migration, and invasion, which is accompanied with cell cycle arrest in G0/G1 phase. Furthermore, luciferase reporter assays indicated that CDKN1B is directly targeted by miR-221 in OS cells. Knockdown of CDKN1B inhibited the effects of miR-221 inhibitor, along with decreased Bax and caspase-3 and increased cyclin E, cyclin D1, Bcl-2, Snail, and Twist1 expression. The results suggested that miR-221 might act as a potentially useful target for treatment of OS.

MiR-204-5p promotes apoptosis and inhibits migration of osteosarcoma via targeting EBF2

Osteosarcoma is one of the most malignant cancer adolescents and young adults and metastatic osteosarcoma is a huge life threat with a 5-year survival lower than 20%. However, the mechanisms through which localized osteosarcoma turned metastatic are not fully understood. Here, we studied the role of miR-204-5p in osteosarcoma and found that miR-204-5p is downregulated in both osteosarcoma patients and osteosarcoma cell lines. In addition, overexpression of miR-204-5p resulted in increase of osteosarcoma cell apoptosis and decrease of osteosarcoma cell migration and invasion. Besides, our in vivo xenograft data showed strong inhibitory role of miR-204-5p in tumor growth. Importantly, our data showed that miR-204-5p regulates the mRNA stability of Early B Cell Factor 2 (EBF2), a crucial regulator in osteosarcoma apoptosis, by directly binding to 3’ UTR of EBF2. Besides, our data further revealed that overexpressed EBF2 inhibited apoptosis and facilitated migration and invasion of osteosarcoma cells. Additionally, EBF2 overexpression rescued the phenotype caused by miR-204-5p.Our data indicated that miR-204-5p is an anti-oncogenic miRNA in osteosarcoma which functions through inhibiting oncogenic transcription factor EBF2. These results provided new therapeutic targets for metastatic osteosarcoma and insights into molecular regulation of EBF2.

MicroRNA-935 Inhibits Proliferation and Invasion of Osteosarcoma Cells by Directly Targeting High Mobility Group Box 1.

Numerous studies have suggested that microRNAs (miRNAs) are dysregulated in osteosarcoma (OS), implicating miRNAs in OS initiation and progression. Therefore, knowledge of aberrantly expressed miRNAs in OS may provide novel mechanistic insights into the tumorigenesis and tumor development of OS and facilitate therapeutic methods for patients with this aggressive bone neoplasm. In this study, data obtained from reverse transcription quantitative polymerase chain reaction (RT-qPCR) revealed that miR-935 was significantly decreased in OS tissues and cell lines. Restoration expression of miR-935 obviously restricted proliferation and invasion of OS cells. In addition, high-mobility group box 1 (HMGB1) was predicted to be a putative target of miR-935. Subsequent dual-luciferase reporter assay, RT-qPCR, and Western blot analysis confirmed that miR-935 could directly target the 3′-untranslated region of HMGB1 and negatively regulated HMGB1 expression in OS cells. Furthermore, a significant negative association was found between miR-935 and HMGB1 mRNA expression in OS tissues. Rescue experiments showed that recovery of HMGB1 expression partially rescued miR-935-induced suppression of cell proliferation and invasion in OS. These results provide the first evidence for the suppressive roles of miR-935 in OS by directly targeting HMGB1, suggesting that miR-935 may be a potential candidate for the treatment of patients with this disease.

MicroRNA‑944 targets vascular endothelial growth factor to inhibit cell proliferation and invasion in osteosarcoma

Emerging evidence has demonstrated that the dysregulation of microRNA (miRNA/miR) serves a crucial role in the tumorigenesis and tumor development of osteosarcoma (OS), primarily by affecting various pathological behaviors. Therefore, better knowledge of miRNA in OS may provide novel insights into the pathogenesis of OS, and may facilitate the development of promising therapeutics for patients with this disease. MiRNA‑944 is frequently dysregulated in human cancers. However, the expression levels, functions and underlying mechanisms of miR‑944 in OS remain largely elusive. In the present study, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was performed to detect miR‑944 expression in OS tissues and cell lines. The regulatory influence of miR‑944 in OS proliferation and invasion was determined with MTT and Transwell invasion assays. In addition, the mechanisms underlying the action of miR‑944 in OS cells were elucidated through a series of experiments, including bioinformatics analysis, luciferase reporter assay, RT‑qPCR and western blot analysis. Spearman's correlation analysis was utilized to examine the relationship between miR‑944 and VEGF expression levels, and rescue experiments were applied to further verify whether VEGF mediates the role of miR‑944 in OS. The results demonstrated that miR‑944 was downregulated in cancer tissues and cell lines. Furthermore, exogenous miR‑944 expression inhibited cell proliferation and invasion in OS invitro. Vascular endothelial growth factor (VEGF) was identified as a direct target of miR‑944 in OS and was overexpressed in cancer tissues. VEGF expression was inversely correlated with miR‑944 expression in cancer tissues. Rescue experiments demonstrated that overexpression of VEGF partially prevented the miR‑944‑induced inhibition of OS cell proliferation and invasion. These results suggested that miR‑944 may serve a tumor suppressive role in OS by directly targeting VEGF. Therefore, miR‑944 may be a promising target in the treatment of OS.