Inhibited Osteosarcoma Cell Migration Research Articles

Asiatic acid inhibits osteosarcoma cell migration and invasion via the AKT/Sp1/MMP1 axis.

Osteosarcoma is a malignant bone tumor affecting adolescents and children. No effective treatment is currently available. Asiatic acid (AA), a triterpenoid compound found in Centella asiatica, possesses anti-tumor, anti-inflammatory, and anti-oxidant properties in various types of tumor cells. This study aims to determine whether AA exerts antitumor effects in human osteosarcoma cells. Our results indicate that AA does not influence the viability, proliferative rate, or cell cycle phase of human osteosarcoma cells under non-toxic conditions. AA suppressed osteosarcoma cell migration and invasion by down-regulating matrix metalloproteinase 1 (MMP1) expression. Data in the TNMplot database suggested MMP1 expression was higher in osteosarcoma than in normal tissues, with associated clinical significance observed in osteosarcoma patients. Overexpression of MMP1 in osteosarcoma cells reversed the AA-induced suppression of cell migration and invasion. AA treatment decreased the expression of specificity protein 1 (Sp1), while Sp1 overexpression abolished the effect of AA on MMP1 expression and cell migration and invasion. AA inhibited AKT phosphorylation, and treatment with a PI3K inhibitor (wortmannin) increased the anti-invasive effect of AA on osteosarcoma cells via the p-AKT/Sp1/MMP1 axis. Thus, AA exhibits the potential for use as an anticancer drug against human osteosarcoma.

Diosgenin glucoside inhibits the progression of osteosarcoma MG-63 by regulating the PI3K/AKT/mTOR pathway.

Trillium tschonoskii Maxim (TTM) exerts antitumor effects on a variety of tumour cells. However, the antitumor mechanism of Diosgenin glucoside (DG) extracted from TTM is not clear. This study aimed to investigate the anti-tumour effects of DG-induced osteosarcoma MG-63 cells and their molecular mechanism. CCK-8 assay, HE staining, and flow cytometry were used to detect the effects of DG on the proliferation, apoptosis, and cell cycle of osteosarcoma cells. Wound healing and Transwell invasion assays were used to observe the effect of DG on the migration and invasion of osteosarcoma cells. The anti-tumour mechanism of DG on osteosarcoma cells was investigated by immunohistochemistry, Western blot, and RT-PCR. DG significantly inhibited osteosarcoma cell activity and proliferation, promoted apoptosis and blocked the G2 phase of the cell cycle. Both wound healing and Transwell invasion assays showed that DG inhibited osteosarcoma cell migration and invasion. Immunohistochemical and western blot results showed that DG inhibited the activation of PI3K/AKT/mTOR. We found that DG also significantly downregulated the expression of S6K1 and eIF4F, which might be associated with the inhibition of protein synthesis. DG may inhibit proliferation, migration, invasion, and cell cycle G2 phase arrest of osteosarcoma MG-63 cells and promote apoptosis through the PI3K/AKT/mTOR signalling pathway.

Network pharmacology-based research on the effect of angelicin on osteosarcoma and the underlying mechanism.

To explore the antitumor effects of angelicin on osteosarcoma and the underlying mechanism. We aimed to elucidate the mechanism by network pharmacology, molecular docking, and in vitro experiments. We analyzed a PPI network of potential angelicin targets in the treatment of osteosarcoma and identified hub targets. We systematically performed GO and KEGG enrichment analyses of the potential targets of angelicin, and we predicted it function in osteosarcoma treatment and the underlying molecular mechanism. Through molecular docking, the interactions between hub targets and angelicin were simulated, and then, the hub targets of angelicin were identified. Based on these results, we validated the effects of angelicin on osteosarcoma cells by conducting in vitro experiments. The PPI network analysis of potential therapeutic targets identified four apoptosis-related hub targets, namely, BCL-2, Casp9, BAX and BIRC 2. GO and KEGG enrichment analyses demonstrated that angelicin regulates osteosarcoma cell apoptosis. Molecular docking results indicated that angelicin can freely bind to the hub targets listed above. In vitro experiments showed that angelicin promoted osteosarcoma cell apoptosis in a dose-dependent manner and inhibited osteosarcoma cell migration and proliferation in a time- and dose-dependent manner. The RT-PCR results showed that angelicin simultaneously promoted the mRNA expression of Bcl-2 and Casp9 and inhibited the mRNA expression of BAX and BIRC 2. Angelicin promotes osteosarcoma cell apoptosis and inhibits osteosarcoma cell proliferation and migration by activating a signaling network that is composed of hub targets that link multiple signaling pathways. Angelicin could become an alternative drug for the treatment of osteosarcoma.

EID3 Promotes Cancer Stem Cell-Like Phenotypes in Osteosarcoma through the Activation of PI3K-AKT Signaling Pathway.

The aim of this study is to elucidate molecular mechanism by which E1A-like inhibitor of differentiation 3 (EID3) promotes cancer stem cell-like phenotypes in osteosarcoma. Overexpression of EID3 in osteosarcoma cells generated more spherical clones, enhanced the expression of stemness-associated genes, and promoted chemoresistance, invasion, and metastasis. Furthermore, osteosarcoma cells overexpressing EID3 had increased ability to grow in suspension as osteospheres with high expression of Sox2 and stem cell marker CD133. In addition, knockdown of EID3 reduced sphere formation and inhibited osteosarcoma cell migration and invasion. RNA sequencing and bioinformatics analysis revealed that PI3K-Akt signaling pathway and MAPK pathway­related genes were enriched in osteosarcoma cells with high expression of EID3. Taken together, EID3 promotes osteosarcoma, and EID3–PI3K-Akt axis is a potential therapeutic target for osteosarcoma treatment.

MicroRNA-302a inhibits osteosarcoma cell migration and invasion by directly targeting IGF-1R.

[This retracts the article DOI: 10.3892/ol.2018.8049.].

Oxyresveratrol Reduces the Migration of Human Osteosarcoma Cell U2OS via Attenuating STAT3 Activation

Objective: Osteosarcoma is a malignant tumor with high metastatic properties that are associated with increased mortality and poor prognosis. Therefore, it is crucial to develop an effective treatment for metastatic osteosarcoma. Oxyresveratrol (ORES), derived from mulberry twigs and fruits, has antitumor effects. However, it remains unknown whether ORES inhibits osteosarcoma metastasis. In this study, we determined the inhibitory effect of ORES on osteosarcoma metastasis. Key Findings: ORES attenuated the migration of U2OS cells, dose-dependently increased E-cadherin expression, and reduced N-cadherin expression in U2OS cells, indicating that ORES can inhibit epithelial–mesenchymal transition (EMT) in osteosarcoma cells. Furthermore, ORES inhibited the expression of Twist, which is associated with the downregulation of STAT3 phosphorylation. IL-6-induced STAT3 phosphorylation rescues the inhibitory effect of ORES on U2OS metastasis. Summary: Our results indicate that ORES is a potential therapeutic agent for metastatic osteosarcoma. ORES inhibits osteosarcoma cell migration by reducing EMT formation.

Oncogenic lncRNA ZNFX1 antisense RNA 1 promotes osteosarcoma cells proliferation and metastasis by stabilizing serine and arginine‑rich splicing factor 3

ABSTRACT Recent studies have demonstrated that lncRNAs play an important role in cancers, particularly osteosarcoma. ZFAS1 is a newly identified and characterized lncRNA linked to a variety of cancers. The role of ZFAS1 in osteosarcoma is mainly unknown. This study discovered that ZFAS1 was upregulated in osteosarcoma patient tissues, which correlates with elevated SRSF3 protein levels. Higher levels of ZFAS1 or SRSF3 were linked to a poor prognosis of osteosarcoma. ZFAS1 knockdown decreased SRSF3 protein levels but had a negligible effect on SRSF3 mRNA expression. Further research indicated that ZFAS1 could bind to the SRSF3 protein directly and prevent degrading. Functional studies revealed that ZFAS1 knockdown inhibited osteosarcoma cell proliferation as measured by the CCK-8 assay, colony formation assay, and Ki-67 immunofluorescence staining. Furthermore, ZFAS1 knockdown reduced the expression of PCNA, CDK1, CDK4, and CDK6, increasing p53 and p16. IT has also been observed that ZFAS1 knockdown inhibited osteosarcoma cell migration and invasion as measured by the wound healing assay and the trans-well assay with or without Matrigel. Furthermore, exogenous SRSF3 expression in ZFAS1-depleted osteosarcoma cells restored SRSF3 expression while simultaneously inhibiting cell proliferation and metastasis. Our findings show that ZFAS1 plays an essential role in osteosarcoma progression by stabilizing the SRSF3 protein. Our study provides novel insight into the role of ZFAS1 in osteosarcoma. ZFAS1 has the potential to be used as a prognostic biomarker as well as a therapeutic target in the treatment of osteosarcoma.

LncRNA DLX6-AS1 regulates osteosarcoma progression via the miR-200a-3p/GPM6P axis

LncRNA DLX6-AS1 takes part in the progression of various cancers. However, it is not elaborated clearly in osteosarcoma (OS) development. Therefore, we aimed to explore the impacts and specific mechanisms of DLX6-AS1 on the progression of OS. We estimated the pattern of DLX6-AS1 expression in Ost tissues and cells via quantitative reverse transcription polymerase chain reaction. A number of biochemical assays were carried out to assess the effects of DLX6-AS1. Target genes were predicted by bioinformatics methods. Then we used the transfection of si-RNA, miRNA inhibitor, and miRNA mimics to explore the underlying mechanisms and built tumor xenograft models for the in vivo experiments. A higher expression of DLX6-AS1 was found in OS tissues and cell lines, while knockdown of DXL6-AS1 suppressed OS cell metastasis and proliferation in vitro and in vivo. Mechanistically, it was revealed that DXL6-AS1 sponged miR-200a-3p, thus positively regulating the downstream GPM6B. In summary, DLX6-AS1 knockdown would inhibit OS cell migration, cell invasion, and cell proliferation, in which the DXL6-AS1/ miR-200a-3p/ GPM6B axis played a critical role.

Synergistic effect of growth factor receptor-bound protein 2/epidermal growth factor receptor dual-targeting peptide inhibitor and salinomycin on osteosarcoma.

The growth factor receptor-bound protein 2 (Grb2)-Sos1 interaction, mediated by modular domains, plays an essential role in the oncogenic MAPK signaling pathway in osteosarcoma (OS). Recently, a dual-targeting peptide that targets the epidermal growth factor receptor and Grb2-Src homology 3 domain in OS cells was designed and synthesized. We investigated the synergistic effects of the peptide and salinomycin (Sal), a chemotherapeutic drug with effective anti-OS properties in clinical therapy. Flow cytometry was used to measure the targeting efficacy of the peptide. Migration and CCK-8 assays were used to explore whether Sal and the peptide could synergistically inhibit OS cell behavior. Western blotting was used to detect apoptosis. Data were analyzed using the GraphPad Prism 5.01. Statistical analysis was performed using the Student's t-test for the direct comparisons and one-way analysis of variance for the comparisons among the multiple groups. Statistical significance was set at P < 0.05. The peptide was shown to target OS cells. When applied together, Sal and the peptide synergistically inhibited OS cell migration, invasion, and proliferation through the inhibition of Grb2-Sos1. This synergistic treatment also promoted the apoptosis of OS cells and inhibited tumor volume in vivo. These data provide valuable insights into the molecular mechanisms of OS and may be beneficial in clinical therapy.

KDM6B-mediated histone demethylation of LDHA promotes lung metastasis of osteosarcoma.

Rationale: Osteosarcoma (OS), the most common type of bone tumor, which seriously affects the patients' limb function and life quality. OS has a strong tendency of lung metastasis, and the five-year survival rate of patients with metastatic osteosarcoma is less than 20%. Thus, new treatment targets and strategies are urgently needed.Methods: The expression of the histone demethylase KDM6B and H3K27me3 levels in OS specimens were analyzed using quantitative PCR and immunohistochemical assays. The biological functions of KDM6B were determined using in vitro transwell, wound healing assays, and an in vivo orthotopic injection-induced lung metastasis model. Subsequently, chromatin immunoprecipitation sequencing (ChIP-seq) combined with transcriptomic RNA sequencing (RNA-seq), and subsequent ChIP-qPCR, western blot, and aerobic glycolysis assays were used to explore the mechanism of KDM6B function and validate the candidate target gene of KDM6B.Results: KDM6B expression was significantly upregulated in OS patients, and high KDM6B expression was associated with poorer prognosis in OS patients. Targeting KDM6B significantly inhibited OS cell migration in vitro and lung metastasis in vivo. RNA-seq and ChIP-seq analysis revealed that KDM6B increases lactate dehydrogenase LDHA expression in OS cells by directly mediating H3K27me3 demethylation. The phenotypes of inhibited cell metastasis in KDM6B-knockdown OS cells was reversed upon overexpression of LDHA. Finally, a small molecule inhibitor targeting KDM6B significantly inhibited OS cell migration in vitro and lung metastasis in vivo.Conclusions: Collectively, we elucidated that upregulated KDM6B facilitates tumor metastasis in OS via modulating LDHA expression. Our findings deepen the recognition of OS metastasis mechanism and suggest that KDM6B might be a new potential therapeutic target for the treatment of OS (especially highly metastatic OS).

MicroRNA‑487b‑3p inhibits osteosarcoma chemoresistance and metastasis by targeting ALDH1A3.

Metastasis and chemoresistance indicate poor prognosis in patients with osteosarcoma (OS). In the present study, the expression level of microRNA(miR)‑487b‑3p in OS specimens and cell lines was found to be decreased, and the expression level of miR‑487b‑3p was associated with overall survival in patients with OS. The inhibition of miR‑487b‑3p stimulated OS cell migration and contributed to the development of chemoresistance. In contrast, the overexpression of miR‑487b‑3p significantly inhibited OS cell migration and enhanced the sensitivity of OS cells to doxorubicin treatment. In addition, the results from the present study revealed that the suppression of miR‑487b‑3p stimulates OS stemness, while the overexpression of miR‑487b‑3p suppresses OS stemness. Notably, invivo experiments also revealed that the overexpression of miR‑487b‑3p inhibited cancer stem cell (CSC)‑induced tumor formation, and the combination treatment of miR‑487b‑3p and doxorubicin significantly inhibited CSC‑induced tumor growth. Furthermore, miR‑487b‑3p exerts its anticancer role by targeting aldehyde dehydrogenase 1 family member A3 in OS. Taken together, the results from the present study suggests that miR‑487b‑3p is a tumor suppressor and that the overexpression of miR‑487b‑3p is a novel strategy to inhibit tumor metastasis and chemoresistance in OS.

MicroRNA-1236-3p inhibits human osteosarcoma growth.

Osteosarcoma (OS) is a common bone tumor with high mortality worldwide. The long-term survival rate of patients with metastatic or recurrent disease is <20%. The present study explored the biological role of microRNA (miRNA/miR)-1236-3p in OS. miRNA and mRNA expression levels were measured via reverse transcription-quantitative PCR. Fluorescence in situ hybridization was performed to determine miR-1236-3p expression levels in clinical specimens. Protein expression was measured via western blotting. Immunohistochemical analysis was used to detect Wnt target gene expression in tumor tissues. The interaction between the Wnt3a 3′untranslated region and miR-1236-3p was assessed via dual-luciferase reporter assays. Cell cycle, Transwell, Cell Counting Kit-8 and wound healing assays were conducted to evaluate the function of the miR-1236-3p/Wnt3a axis. Human OS (HOS) cells stably transfected with vector or miR-1236-3p sponge were injected subcutaneously into nude mice to assess the role of miR-1236-3p in vivo. miR-1236-3p expression was downregulated in OS tissues compared with chondroma tissues, and miR-1236-3p overexpression inhibited OS cell migration and proliferation compared with the negative control group. Furthermore, in vivo xenograft assays displayed enhanced tumour growth rates in the miR-1236-3p sponge group compared with the vector control group. In the present study, the results indicated that miR-1236-3p inhibited OS progression and Wnt3a was identified as a target of miR-1236-3p.

Targeted MEK inhibition by cobimetinib enhances doxorubicin’s efficacy in osteosarcoma models

The limited effectiveness and high toxicity of current treatments in osteosarcoma necessitate new therapeutic strategy. Cobimetinib is a FDA-approved MEK inhibitor and is clinically used in combination with standard of care to treat melanomas. Here, we report that targeted MEK inhibition by cobimetinib enhances doxorubicin’s efficacy in osteosarcoma models. We found that cobimetinib potently inhibited growth and survival of osteosarcoma cells. We revealed that cobimetinib had anti-metastasis activity as it inhibited osteosarcoma cell migration. Notably, the effective concentrations of cobimetinib are clinically achievable. We further found that cells with the most sensitivity had highest p-ERK and cells with the least sensitivity had lowest p-ERK, suggesting the possible correlation of ERK activation with cobimetinib sensitivity in osteosarcoma. We further confirmed that inhibition of MEK/ERK signaling pathway is the mechanism of cobimetinib’s action in osteosarcoma, leading to inhibition of focal adhesion kinase (FAK) and anti-apoptotic pathway, as well as activation of pro-apoptotic pathway. Using xenograft mice model, we found that cobimetinib at the tolerable dose significantly inhibited osteosarcoma formation and growth. In addition, the combination of cobimetinib and doxorubicin at sublethal dose completely arrested tumor growth without further progression. The ability of cobimetinib in enhancing doxorubicin’s efficacy in osteosarcoma models makes cobimetinib as a useful addition to the treatment armamentarium for osteosarcoma. Our findings also emphasize the therapeutic value of MEK/ERK pathway to improve the clinical management of osteosarcoma.

LAIR-1 overexpression inhibits epithelial\u2013mesenchymal transition in osteosarcoma via GLUT1-related energy metabolism

BackgroundLeukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is a collagen receptor belonging to the immunoglobulin superfamily. Although previous studies have evaluated the biological role of LAIR in solid tumors, the precise mechanisms underlying the functions of LAIR-1 as a regulator of tumor biological functions remain unclear.MethodsLAIR-1 expression was evaluated by immunohistochemical analysis using an osteosarcoma (OS) tissue microarray. Wound healing and transwell migration assays were performed to evaluate tumor cell migration. Quantitative real-time polymerase chain reaction (qPCR) and western blotting were conducted to detect the expression of epithelial–mesenchymal transition (EMT)-related molecules. RNA-sequencing (RNA-seq) was conducted to evaluate the mRNA expression profiles after overexpressing LAIR-1 in OS cells. Glucose transporter (Glut)1 expression in OS cells was evaluated by western blotting.ResultsLAIR-1 expression was significantly different between the T1 and T2 stages of OS tumors, and it inhibited OS cell migration. LAIR-1 expression was inversely correlated with the expression of Twist1, an EMT-associated transcription factor, via the Forkhead box O1 signal transduction pathway. Furthermore, RNA-seq and qPCR demonstrated that the expression of EMT energy metabolism-related molecules was significantly reduced after LAIR-1 overexpression.ConclusionsLAIR-1 overexpression decreased the expression of Glut1 and inhibited the expression of EMT-related molecules in OS cells. These findings provide new insights into the molecular mechanism underlying OS progression.

PENK inhibits osteosarcoma cell migration by activating the PI3K/Akt signaling pathway

BackgroundThis article reports the effects of proenkephalin (PENK) on osteosarcoma (OS) cell migration.MethodsA Gene Expression Omnibus (GEO) dataset was used to identify differentially expressed genes (DEGs) in OS tumor samples and normal human osteoblasts. Tumor tissue and adjacent normal tissue were collected from 40 OS patients. MG63 cells were transfected with si-PENK. Transwell migration assays and wound healing assays were performed to compare the effect of PENK on migration. Moreover, LY294002 was used to identify the potential mechanism. Gene expression was examined via qRT-PCR and Western blotting.ResultsBioinformatic analysis revealed that PENK was downregulated in OS tumor samples compared with normal human osteoblasts. Moreover, PENK was identified as the hub gene of the DEGs. The PI3K/Akt signaling pathway was significantly enriched in the DEGs. Moreover, PENK was downregulated in OS and MG63 cells compared with the corresponding control cells. Silencing PENK promoted MG63 cell migration; however, treatment with LY294002 partially attenuated PENK silencing-induced OS cell migration.ConclusionPENK inhibits OS cell migration by activating the PI3K/Akt signaling pathway.

MicroRNA-320a inhibits invasion and metastasis in osteosarcoma by targeting cytoplasmic polyadenylation element-binding protein 1.

Osteosarcoma is a primary malignant bone tumor, which affects children, adolescents, and young adults commonly. MicroRNAs (miRNAs) have been proved to be dysregulated in different cancers, including osteosarcoma. Although miR‐320a has been implicated in many types of malignancies, little is known about the role of miR‐320a in osteosarcoma. In this study, we show that the overexpression of miR‐320a or knockdown of cytoplasmic polyadenylation element‐binding protein 1 (CPEB1) inhibited osteosarcoma cell migration and invasion. miR‐320a downregulates CPEB1 expression by directly targeting the CPEB1 3′‐UTR. Furthermore, CPEB1 reintroduction reversed the antiproliferation, antimigration, and antiinvasion roles of miR‐320a, indicating that miR‐320a might function as a tumor suppressor in osteosarcoma through CPEB1. In conclusion, our study demonstrates that miR‐320a plays a critical role in osteosarcoma progression and may provide a potential therapeutic target for osteosarcoma.

LncRNA GAS8-AS1 downregulates lncRNA UCA1 to inhibit osteosarcoma cell migration and invasion

BackgroundOsteosarcoma (OS) is the most common type of primary bone tumor that mainly affects adolescents and young adults. The present study explored the role of lncRNA GAS8-AS1 in OS.MethodsA total of 48 OS patients were selected from the 82 OS patients admitted by Luoyang Orthopedic Hospital of Henan Province between May 2010 and May 2013. Transient cell transfections, Transwell cell migration and invasion assay, RT-qPCR, and patient follow-up were carried out during the research.ResultsThe results showed that GAS8-AS1 was downregulated, while UCA1 was upregulate in cancer tissues in comparison to adjacent non-cancer tissues of OS patients. GAS8-AS1 was not affected by clinical stage. Follow-up study showed that downregulated GAS8-AS1 in cancer tissues was closely correlated with poor survival. GAS8-AS1 and UCA1 were inversely correlated in cancer tissues. Overexpression of UCA1 failed to affect the expression of GAS8-AS1, while overexpression of GAS8-AS1 led to downregulated expression of UCA1 in OS cells, while the molecular mediators between these two lncRNAs are unknown. Overexpression of GAS8-AS1 did not affect OS cell proliferation but significantly inhibited cancer cell migration and invasion. Overexpression of UCA1 promoted the migration and invasion of OS cells and attenuated the effects of overexpressing GAS8-AS1.ConclusionsTherefore, GAS8-AS1 may inhibit OS cell migration and invasion by downregulating oncogenic UCA1.

LncRNA HOTTIP facilitates osteosarcoma cell migration, invasion and epithelial-mesenchymal transition by forming a positive feedback loop with c-Myc.

Homeobox A transcript at the distal tip (HOTTIP) is an oncogenic long non-coding RNA in cancer. The aim of the present study was to investigate the function and mechanism of HOTTIP in the aggressive behaviors of human osteosarcoma (OS) cells. Expression levels of HOTTIP and epithelial-mesenchymal transition (EMT) markers were determined by reverse transcription-quantitative PCR. Cell invasive and migratory abilities were evaluated in vitro using Matrigel and wound healing assays, respectively. Knockdown of HOTTIP expression was achieved by small interfering RNA-mediated silencing. Overexpression of c-Myc was accomplished by transfecting cultured cells with a c-Myc overexpression plasmid. HOTTIP was demonstrated to be upregulated in OS tissues and cell lines; knockdown of HOTTIP inhibited OS cell migration, invasion and EMT, and suppressed c-Myc expression. In addition, overexpression of c-Myc increased HOTTIP expression and enhanced OS cell migration and invasion. HOTTIP promoted cell migration and invasion by upregulating c-Myc in OS. The positive feedback loop formed by HOTTIP and c-Myc may contribute to OS progression, and HOTTIP may act as a therapeutic target for OS.

Ubiquitin‑specific protease 7 promotes osteosarcoma cell metastasis by inducing epithelial‑mesenchymal transition.

Osteosarcoma (OS) is the most common primary malignant bone tumour among adolescents and young adults; however, its molecular pathogenesis has not been completely elucidated. Ubiquitin‑specific protease 7 (USP7), a member of the deubiquitinating enzyme family, plays a role in the malignancy process of various cancer types by targeting the key oncoprotein; however, its biological function and mechanism in OS have not been elucidated. The present study demonstrated that USP7 expression in OS tumour tissues was markedly higher than that in the paired surrounding tissues, and high USP7 expression was positively correlated with the TNM stage and metastasis in patients with OS. Next, biological function assays demonstrated that USP7 knockdown markedly inhibited OS cell migration and invasion, whereas USP7 overexpression enhanced it. Notably, USP7 can directly bind with β‑catenin to activate the Wnt/β‑catenin signalling pathway and induce epithelial‑mesenchymal transition (EMT) of OS cells. Overall, USP7 overexpression could promote OS cell metastasis by activating the Wnt/β‑catenin signalling pathway by inducing EMT, suggesting that USP7 is a potential therapeutic target for OS.

Overexpression of RBM10 induces osteosarcoma cell apoptosis and inhibits cell proliferation and migration.

Osteosarcoma is the most common malignant bone tumor with high incidence in adolescence and poor prognosis. RBM10, a member of RBPs, was reported to be a tumor suppressor in many kinds of cancers. However, the roles of RBM10 in osteosarcoma remain unknown. In this study, we found that overexpression of RBM10 decreased osteosarcoma cell proliferation and colony formation in soft agar, and inhibited osteosarcoma cell migration and invasion. Our results also revealed that RBM10 overexpression induced osteosarcoma cell apoptosis via the inhibition of Bcl-2, the activation of caspase-3, and the transcription and production of TNF-α. Our results indicated that RBM10 acts as a tumor suppressor in osteosarcoma. This could enable to define a new strategy for diagnosis and treatment of patients with osteosarcoma.