Osteosarcoma Cell Line MG-63 Research Articles

Polydatin enhances the chemosensitivity of osteosarcoma cells to paclitaxel.

Despite improvements in the prognosis of osteosarcoma patients, chemotherapy fails in a considerable number of cases due to drug resistance. The development of novel agents may enhance chemosensitivity. This study explored the anticancer function of polydatin and its ability-in combination with paclitaxel-to overcome drug resistance in human osteosarcoma U-2OS and MG-63 cell lines. A cell proliferation assay (celll counting kit-8), a cell-cycle assay, an apoptosis assay (annexin V-fluorescein isothiocyanate/propidium iodide), and a cell migration assay (Transwell) were used to analyze cell activity. Western blot analysis and quantitative reverse-transcription polymerase chain reaction were performed to examine function-related mRNA and protein levels. Treatment with polydatin suppressed cell growth and migration in both cell lines. Moreover, polydatin induced cell apoptosis in both parental and paclitaxel-resistant cells, and cell-cycle arrest in the S phase. Furthermore, it altered the expression of various proteins associated with cell growth (Ki67, p21, cyclin A, cyclin E, and cyclin-dependent kinase 2), migration (matrix metalloproteinase-2 [MMP-2], MMP-9, and tissue inhibitor of metalloproteinase-1), apoptosis (poly[ADP-ribose] polymerase 1 and caspase 3), and drug resistance (p-glycoprotein 1, lung resistance-related protein 1, growth arrest and DNA damage-45α, glutathione S-transferase π, and heat shock protein 27) in paclitaxel-resistant osteosarcoma cells. Cells transfected with myr-Akt caused obvious upregulation and activation of Akt, which were significantly attenuated via polydatin treatment. In conclusion, polydatin may enhance the chemosensitivity of osteosarcoma cells to paclitaxel.

EP1 receptor is involved in prostaglandin E2-induced osteosarcoma growth.

Recent studies showed that the activation of prostaglandin (PG) receptor EP1 promotes cell migration and invasion in different cancers. The aim of this study was to investigate the role of EP1 in the proliferation of osteosarcoma (OS) cells in vitro and in vivo. EP1 mRNA and protein levels were analyzed by real-time RT-PCR and Western blot, respectively in human OS cell lines MG63, OS732, U-2OS, and 143B compared to human fetal osteoblastic hFOB 1.19 cells. MG63 cells were treated with PGE2, EP1 specific agonist 17-PT-PGE2, 17-PT-PGE2 + EP1 specific antagonist SC51089, or DMSO (control). EP1R-siRNA or a non-silencing irrelevant RNA duplex (negative control) were used for the transfection of MG63 cells, followed by PGE2 treatment. Nude mice carrying MG63 xenografts were treated with SC51089 (2 mg/kg/day). MG63 cells/xenografts were analyzed by MTT assay, TUNEL assay, PKC enzyme activity assay, and Western blot (EP1 and apoptotic proteins), and tumor growth/volume was evaluated in mice. EP1 levels were significantly higher in OS cells compared to osteoblasts. PGE2 or 17-PT-PGE2 treatment increased the proliferation and decreased the apoptosis of MG63 cells. Inhibition of EP1 by SC51089 or siRNA markedly decreased the viability of MG63 cells. Similarly, SC51089 treatment significantly inhibited MG63 cell proliferation and promoted apoptosis in vivo. The silencing of EP1 receptor by siRNA or blockade of EP1 signaling by SC51089 activated extrinsic and intrinsic apoptotic pathways both in vivo and in vitro, as evidenced by increased levels of Bax, cyt c, cleaved caspase-3, caspase-8 and caspase-9. EP1 appears to be involved in PGE2-induced proliferative activity of MG63 cells. Antagonizing EP1 may provide a novel therapeutic approach to the treatment of OS.

Salidroside suppresses the growth and invasion of human osteosarcoma cell lines MG63 and U2OS in vitro by inhibiting the JAK2/STAT3 signaling pathway.

Previous research has reported that salidroside exerts antitumor properties on numerous types of tumor cells; however, its effect on osteosarcoma cells remains unknown. The present study aimed to investigate the effects of salidroside on the viability, apoptosis and invasion of osteosarcoma cells in vitro, and determine the underlying mechanism of action. The results of an MTT revealed that salidroside suppressed the viability of osteosarcoma cells (MG63 and U2OS cells) in a time- and concentration-dependent manner. The results of cell morphological analysis (profile observations and Hoechst 33258 staining) and the detection of apoptosis by flow cytometry further indicated that the decrease in osteosarcoma cell viability induced by salidroside was associated with cell apoptosis. Western blot analysis not only confirmed these results but also suggested that salidroside induced the apoptosis of osteosarcoma cells by activating the caspase-9-dependent apoptotic pathway. In addition, we reported that salidroside induced G0/G1 phase arrest and suppressed the invasion of osteosarcoma cells, as measured by flow cytometric cell cycle analysis and a Transwell invasion assay, respectively. Western blot analysis confirmed the aforementioned results. Furthermore, our findings demonstrated that salidroside induced the apoptosis, G0/G1 phase arrest and suppressed the invasion of osteosarcoma cells by inhibiting the janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway, as determined by western blot analysis. In summary, the findings of the present study suggested that salidroside may inhibit the progression of osteosarcoma by suppressing the growth and invasion of osteosarcoma cells. Furthermore, the investigations into the underlying mechanism demonstrated that salidroside exerted notable antitumor activity in osteosarcoma cells by inhibiting the JAK2/STAT3 signaling pathway.

Velvet Antler compounds targeting major cell signaling pathways in osteosarcoma - a new insight into mediating the process of invasion and metastasis in OS

AbstractVelvet antler is the only renewable bone tissue of mammalian animals, which consists of a variety of growth factors, amino acids and polypeptides. But the mechanism of high-speed proliferation without carcinogenesis is still mystifying. The previous study of this work found that the velvet antler peptides (VAP) could not only inhibit the proliferation and migration of osteosarcoma cell lines MG-63 and U2OS, but also induced U2OS apoptosis and inhibited MG-63 epithelial-mesenchymal transition (EMT) through TGF-β and Notch pathways. These results lead us to conclude that VAP has the potential ability to mediate osteosarcoma cells by regulating related signaling pathways and growth factors. Therefore, finding a new appropriate inhibitor for OS is a valuable research direction, which will give patients a better chance to receive proper therapy. From an applied perspective, this review summarized the effects of velvet antler, genes, growth factors and research progress of relative pathways and genes of osteosarcoma, which are poised to help link regenerative molecular biology and regenerative medicine in osteosarcoma pathogenesis.

LINK-A lncRNA functions in the metastasis of osteosarcoma by upregulating HIF1α.

Long intergenic non-coding RNA for kinase activation (LINK-A) long non-coding RNA (lncRNA) is an oncogenic lncRNA in triple-negative breast cancer. The involvement of LINK-A lncRNA in other diseases is unknown. The present study aimed to investigate the possible involvement of LINK-A lncRNA in osteosarcoma. The results demonstrated that plasma levels of LINK-A lncRNA were significantly higher in patients with metastatic osteosarcoma (MO) compared with healthy controls and patients with non-metastatic osteosarcoma (NMO). LINK-A lncRNA overexpression significantly promoted cancer cell migration and invasion in osteosarcoma cell lines MG-63 and U20S. Upregulated expression of hypoxia-inducible factor 1α (HIF1α) was observed in cancer cells following LINK-A lncRNA overexpression. Exogenous HIF1α treatment did not significantly affect the expression of LINK-A lncRNA in cancer cells, whereas treatment with an HIF1α inhibitor significantly attenuated the effects of LINK-A lncRNA overexpression on cancer cell migration and invasion. Based on the results it was concluded that LINK-A lncRNA participated in the metastasis of osteosarcoma by upregulating HIF1α; upregulation of LINK-A lncRNA may serve as a potential diagnostic biomarker for patients with MO but not in those with NMO.

Tankyrase1 antisense oligodeoxynucleotides suppress the proliferation, migration and invasion through Hippo/YAP pathway in human osteosarcoma cells

Osteosarcoma is the most common malignant tumor of bone with a high potential for metastasis and poor prognosis. This study intends to explore the effect of tankyrase1 (TANK1) in the development of osteosarcoma cells and the underlying mechanism. The osteosarcoma cell line MG-63 cells were cultured and transfected with tankyrase1 antisense oligodeoxynucleotides (TANK1-ASODN). Cell proliferation was detected with CCK-8 and immunofluorescence. Cell migration and invasion were examined by wound healing assay and Transwell assay, respectively. Reverse transcription-quantitative polymerase chain reaction was performed to detect the mRNA level of TANK1 and western blot was conducted to detect relative protein expression during the research. As a result, we demonstrated that TANK1 was upregulated in osteosarcoma. The TANK1-ASODN inhibited MG-63 cell proliferation, migration and invasion. The progress of epithelial-mesenchymal transition (EMT) was also suppressed in TANK1-ASODN transfected MG-63 cells compared to control group. Besides, the TANK1-ASODN activated and modulated the Hippo/YAP signaling which might be the pathway that TANK1 depended on. Overall, our finding supported that TANK1-ASODN slowed down the progress of osteosarcoma by suppressing cell proliferation, migration, invasion and EMT through Hippo/YAP pathway.

The oncogenic role of GNL3 in the progression and metastasis of osteosarcoma.

BackgroundGNL3 has been reported to be up-regulated in cancers and function in tumor progression, whereas the role of GNL3 in the progression of osteosarcoma remains unclear.Materials and methodsIn this study, we blocked the expression of GNL3 by siRNA interference in osteosarcoma cell lines MG63 and U20S. CCK8, colony formation, wound-healing, Transwell, flow cytometry, and Hoechst/PI staining assays were used to examine the effects of GNL3 knockdown on cell proliferation, migration, invasion and apoptosis in MG63 and U20S cells. The relative activity of MMP9 was detected using Gelatin zymography assay. Western blot was performed to detect the expression of related proteins.ResultsWe found that silencing of GNL3 reduced the growth, migration, and invasion abilities of MG63 and U20S cells. Moreover, silencing GNL3 triggered cell cycle arrest in MG63 and U20S cells, as well as promoted cell apoptosis. In addition, depletion of GNL3 was observed to reduce the activity of MMP9 and suppress the process of epithelial–mesenchymal transition (EMT) through up-regulation of E-cadherin and down-regulation of N-cadherin. Furthermore, we found that X-box-binding protein 1 (XBP1) could bind to GNL3 using dual-luciferase reporter assay, and XBP1 overexpression could restore the inhibitory effects on proliferation, invasion, and EMT in MG63 and U20S cells caused by GNL3 knockdown.ConclusionThese data suggest that GNL3 functions as an oncogene in the progression of osteosarcoma by regulation of EMT, and XBP1 is also involved in its mechanism.

Novel synthesis of silica-coated Eu:Gd2O3 nanoparticles by polyol route at low temperature for bimodal cancer imaging

This article reports the novel synthesis of europium doped gadolinium oxide (Eu:Gd2O3) nanoparticles at low temperature by the polyol method for the first time. The role of triethylene glycol (TEG) on the magnetic and optical properties was studied. The cytotoxicity of the nanoparticles and their applications in magnetic resonance imaging (MRI) and optical imaging was also reported. Silica is coated over the nanoparticles to improve the biocompatibility. Spherical nanoparticles with an average diameter of ∼40 nm were synthesized and silica with thickness around 5 nm was coated on the nanoparticles. In the photoluminescence studies, the characteristic emission of Eu3+ ions at 612 nm due to the 5D0 → 7F2 transition was observed. The lifetime of the uncoated and silica-coated nanoparticles were found to be 1.14 and 0.83 ms respectively. The cell viability was assessed in MG63 osteosarcoma cell line by the MTT assay. The results show that the silica-coated nanoparticles possess negligible toxicity till the concentration of 200 μg ml−1. Within this limit, as the concentration of the nanoparticle is increased, the MRI results reveal bright contrast images with the relaxivity value of 4.8 mM−1 s−1, which is higher than the commercially available contrast agents.

α,γ-Diketocarboxylic Acids and Their Esters Act as Carbonic Anhydrase IX and XII Selective Inhibitors.

Among human carbonic anhydrase (CA) inhibitors, the α,γ-diketocarboxylic acids and esters are still poorly investigated. Here, we report the first compounds of this class (1-6) acting as potent inhibitors at low nanomolar level against the cancer-related human CA IX and XII, and 2-3 magnitude orders selective toward the cytosolic isoforms hCA I and II. At enzymatic level, the α,γ-diketoacids 1-3 were more effective inhibitors compared to the corresponding ethyl esters 4-6. The phenyl- and α-naphthyl-containing compounds (1, 3, 4, and 6) behaved as dual hCA IX/XII inhibitors, while the β-naphthyl analogues (2 and 5) exhibited hCA IX-selective inhibition. In MG63 and HOS osteosarcoma (OS) cell lines, the ethyl esters 5 and 6 displayed dose-dependent reduction of viability and proliferation after 72 h treatment, with 6 being more potent than 5 likely for its dual hCA IX/XII inhibition.

Evaluation of the mechanisms and effects of Mg-Ag-Y alloy on the tumor growth and metastasis of the MG63 osteosarcoma cell line.

Osteosarcoma is a malignant primary bone tumor, which often associates with pulmonary metastasis. The radical surgery of osteosarcoma often requires internal orthopedic implants. Therefore, implants with antitumor properties should be developed. Magnesium (Mg) and its alloys possess great potential as orthopedic materials, given their biodegradable properties, superior osteogenesis performance, and antitumor features. However, problems arise with their uncontrolled degradation rates and their unknown antitumor mechanisms. In our study, when compared with pure Mg, the rare element silver alloyed with yttrium (Ag-Y) could extremely enhance the corrosion resistance of these elements, giving the Ex-Mg-1Ag-1Y alloy better anticorrosion rates. Here, we implanted the Ex-Mg-1Ag-1Y alloy and pure Mg and Ti alloy in vivo around tumors in nude mice (BALB/c). Notably, the local tumor weight in Mg alloy and pure Mg groups were much smaller than that in Ti alloy group in 36 days after surgery (6.59 ± 0.70, 6.76 ± 0.62, and 8.54 ± 0.56 g), while the general scores of lung metastasis in Mg alloy and pure Mg groups were also lower than Ti alloy group (64.50 ± 7.64, 62.73 ± 7.84, and 87.60 ± 9.43). Therefore, the Mg and Ex-Mg-1Ag-1Y alloy, both demonstrated resisting effects against local tumor growth and pulmonary metastasis, which could be performed by changing the extracellular acidosis microenvironment, elevating the Mg concentration, suppressing C-X-C chemokine receptor type 4 (CXCR4) levels, and increasing prostacyclin (PGI2 ) synthesis. Our work revealed that the Ex-Mg-1Ag-1Y alloy may be a promising orthopedic implant for treating osteosarcoma due to its better corrosion resistance and antitumor attributes. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2537-2548, 2019.

DDX10 overexpression predicts worse prognosis in osteosarcoma and its deletion prohibits cell activities modulated by MAPK pathway

Osteosarcoma (OS) is an invasive cancer in the skeletal system. The molecular mechanism of its etiology and pathogenesis are still not clear, so the effective treatment strategy of OS needs further research. First, we analyzed the expression level and prognostic ability of the RNA helicase DDX10 in OS patients based on the data obtained from GEO database. Next, we used CCK8 to test OS cell viability. Besides, we used wound-healing assay and transwell migration assay to detect cell migration of OS MG63 cell line. And the cell invasion was tested by transwell invasion assay. Moreover, we used QRT-PCR and western blot to analyze the mRNA and protein expression levels. We found that DDX10 was significantly over-expressed in OS patients and elevated level of DDX10 was associated with a poor prognosis. Silencing of DDX10 inhibited proliferation, invasion and migration of MG63 cells in vitro. Down-regulation of DDX10 inhibited MAPK signaling pathway. The expression of p-MEK and p-ERK were also decreased by silencing of DDX10. Therefore, Silencing of DDX10 inhibited proliferation, invasion and migration of MG63 cells, which might be regulated by suppression of MAPK pathway. In conclusion, our results unfold a novel area of studying for understanding how DDX10 functions in OS oncogenic and prognostic significance, accordingly implying a promising therapeutic target for OS treatment.

Thrombospondin 1 Triggers Osteosarcoma Cell Metastasis and Tumor Angiogenesis.

Osteosarcomas, especially those with metastatic or unresectable disease, have limited treatment options. The antitumor effects of pharmacologic inhibitors of angiogenesis in osteosarcomas are hampered in patients by the rapid development of tumor resistance, notably through increased invasiveness and accelerated metastasis. Here we demonstrated that thrombospondin 1 (TSP-1) is a potent inhibitor of the growth and metastasis of the osteosarcoma cell line MG-63. Moreover, we demonstrate that upregulation of TSP-1 facilitated expression of vasculostatin in MG-63 cells. In angiogenesis assays, overexpression of TSP-1 inhibited MG-63 cells and induced tube formation of human umbilical vein endothelial cells (HUVECs) in a CD36-dependent fashion. Finally, in xenografted tumors, we observed that TSP-1 overexpression inhibited angiogenesis and tumor growth. These results provided strong evidence for an important role of the TSP-1/CD36/vasculostatin signaling axis in mediating the antiangiogenic activity of osteosarcoma.

Impact of transition metal ions on the structure and bioactivity of alkali-free bioactive glasses

Transition metal ions are essential micronutrients for all living organisms and play an important role in bone metabolism. In the present study, we investigated the impact of transition metal ions (Cu, Co, Mn, Fe) on the structure and bioactivity of bioactive glasses. The emphasis was laid on understanding their influence on the chemical dissolution behavior of glasses and its impact on their vitro bioactivity, osteoblast proliferation and oxidative stress levels. The structure of glasses was studied by using molecular EXAFS in combination with Raman spectroscopy. The apatite-forming ability of glasses has been investigated by X-ray diffraction, infrared spectroscopy after immersion of glass powders in simulated body fluid (SBF) for time durations varying between 1 and 7 days. A significant effect on the bioactivity was observed with addition of transition metal ions. The cellular responses were observed in vitro on glass powders using human osteosarcoma MG63 cell line. The dose-dependent cytoprotective effect of glasses with respect to the concentration of transition metal ions (Cu, Co, Mn, Fe) released from the glasses is also discussed.

A new Dy(III)-based metal-organic framework with polar pores for pH-controlled anticancer drug delivery and inhibiting human osteosarcoma cells

Anticancer drug delivery is considered as the most common and patient acceptable drug administration with reduced side effects. In general, an ideal drug carrier for anticancer drug delivery should have high drug loading capacity, good biocompatibility, and avoid drug delivery in normal tissue (neutral conditions) and promoting the drug release in cancerous tissue (acidic condition). Herein, we synthesize a new porous Dy(III)-based metal-organic framework, [Dy(HABA)(ABA)](DMA)4] (1, H2ABA = 4,4'-azanediyldibenzoic acid, DMA = N,N-dimethylacetamide) with uncoordinated N donor sites in the porous surroundings using a bent polycarboxylic acid linker under solvothermal conditions. The structure of the obtained crystalline product has been determined by X-ray single-crystal diffraction, elemental analysis, TGA, XRD, and gas sorption measurement. Due to the suitable window size and polar atom functionalized 1D channels, the activated 1 (1a) was used for anticancer drug 5-Fu loading. A moderately high drug loading and pH-dependent drug-release behavior could be observed for 1a. Furthermore, as demonstrated by the MTT assay, this drug/MOF composite shows low cytotoxicity, good biocompatibility, and anticancer activity against human osteosarcoma cell lines MG63.

Interleukin-35 suppresses antitumor activity of circulating CD8+ T cells in osteosarcoma patients

ABSTRACTPurpose/Aim of the study: Interleukin (IL)-35 is a newly identified IL-12 cytokine family member and reveals immunosuppressive activity to CD8+ T cells in inflammation, infectious diseases, and cancers. However, little is known regarding IL-35 function in osteosarcoma. Thus, the aim of the current study was to investigate the regulatory function of IL-35 to CD8+ T cells in osteosarcoma.Materials and methods: Thirty-five osteosarcoma patients and 20 healthy individuals were enrolled. Serum CD4+CD25+CD127dim/– regulatory T cells (Tregs) and CD8+ T cells were purified. IL-35 concentration in serum and cultured supernatants was measured by enzyme-linked immunosorbent assay. Osteosarcoma cell line MG-63 cells and CD8+ T cells were stimulated with recombinant IL-35 in vitro, and modulatory function of IL-35 on these cells was assessed by investigation of cellular proliferation, cell cycle, apoptosis, and cytokine production.Results: Serum IL-35 and Treg-secreting IL-35 were significantly elevated in osteosarcoma patients. IL-35 stimulation did not affect proliferation, apoptosis, or cell cycle of MG-63 cells. Purified peripheral CD8+ T cells from osteosarcoma patients revealed dysfunctional property, which presented as decreased mRNA expressions for perforin, granzyme B, and granulysin, as well as reduced cytolytic (direct lysis of target MG-63 cells) and noncytolytic (interferon-γ and tumor necrosis factor-α production) function in coculture systems. Moreover, IL-35 stimulation further diminished cytolytic and noncytolytic activity of CD8+ T cells from osteosarcoma patients.Conclusions: The current data indicated that IL-35 contributed to CD8+ T-cell dysfunction and limited antitumor immune response in osteosarcoma.

Identification of differentially expressed genes in MG63 osteosarcoma cells with drug‑resistance by microarray analysis.

Osteosarcoma is the most common type of primary malignant bone tumor, with extremely poor prognosis in patients with metastatic disease and resistance to therapy, such as multidrug regimens. The mechanisms of drug resistance are quite complex and have not been fully elucidated; thus, novel therapeutic targets should be identified to alleviate drug resistance in osteosarcoma. In the present study, the transcriptomes of the human osteosarcoma cell line MG63 and vincristine (VCR)-resistant MG63 cells were compared by microarray analysis. A total of 1,300 genes (602 upregulated and 698 downregulated) were reported to be differentially expressed in MG63/VCR compared with MG63 cells. Bioinformatics analysis predicted that the differentially expressed genes were mainly enriched in the B cell receptor, UVA-induced mitogen-activated protein kinases and receptor tyrosine kinase 2/3 signaling pathways. In the present study, 10 of the dysregulated genes, including roundabout homolog 1, death-associated protein kinase 1 and A-kinase anchor protein 12 were further evaluated by reverse transcription-quantitative polymerase chain reaction. These results may aid the validation of candidate biomarkers for the treatment and prognosis of osteosarcoma, and provide novel insight into the molecular mechanisms underlying the drug resistance of osteosarcoma cells.

Killing effect of oncolytic adenovirus Ad11 containing human telomerase reverse transcriptase combined with ifosfamide on human osteosarcoma cells and possible mechanism

Objective To study the killing effect of oncolytic adenovirus Ad11 combined with ifosfamide on human osteosarcoma cells and the possible mechansim, and provide cytological basis for oncolytic adenovirus Ad116 in the treatment of osteosarcoma. Methods The human osteosarcoma cell line MG63 was cultured in vitro, and the 50% maximal effect concentration (EC50) of Ad11 and the 25% inhibitory concentration (IC25) and 50% inhibitory concentration (IC50) of adrephosphamide were detected by cytotoxicity assay (MTS method). The MTS method was used to detect the cell viability of the control group, Ad11 group [multiplicity of infection (MOI)=5], ifosfamide group 1 (IC25=15 μmol/ml), ifosfamide group 2 (IC50=25 μmol/ml), combined group 1 (Ad11+ IC25) and combined group 2 (Ad11+ IC50). Western blotting was used to detect the expression of autophagy-related proteins Beclin-1 and LC3A/B in the control and experimental groups. Results The MTS assay showed that Ad11 treatment of osteosarcoma cells had an EC50 value of 5.26 MOI, and combined with ifosfamide had synergistic killing effect on osteosarcoma cell MG63. Western blotting results showed that autophagy induced by ifosfamide was inhibited when Ad11 was treated with ifosfamide. Conclusion Ad11 has a killing effect on osteosarcoma cell line MG63. The synergistic effect is enhanced when Ad11 is combined with ifosfamide. The synergistic effect may be due to the weakened protective autophagy of MG63 cells. Key words: Oncolytic adenovirus; Ad11; Osteosarcoma; Autophagy; Ifosfamide

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.

Inhibitory effect of MSH6 gene silencing in combination with cisplatin on cell proliferation of human osteosarcoma cell line MG63

Osteosarcoma (OS) is one of the most common primary bone malignancies, with the survival rate of patients with OS remaining low. Therefore, we conducted this study to identify the potential role combination of both MSH6 gene silencing and cisplatin (DDP) plays in OS cell proliferation and apoptosis. Microarray-based gene expression profiling was used to identify the differentially expressed genes (DEGs) in patients with OS, as well as microRNAs (miRNAs) that regulate the candidate gene. OS tissues from 67 patients with OS along with normal tissues from 24 amputee patients were collected for detection of the positive expression of mutS homolog 6 (MSH6) protein, mRNA, and protein expressions of c-myc, cyclin D1, l-2, B-cell lymphoma 2 (Bcl-2), Stathmin, proliferating cell nuclear antigen (PCNA), and Bcl-2-associated X (Bax). Moreover, after MSH6 silencing and DDP were treated on the selected human OS cell line MG63 with the highest expression of MSH6, cell viability, cell cycle distribution, and apoptosis were detected. The microarray analysis showed that MSH6 was upregulated in OS chip data. Furthermore, silencing MSH6 combined with DDP reduced expressions of c-myc, cyclin D1, Bcl-2, Stathmin, and PCNA, and elevated Bax expression, whereas inhibiting OS cell viability, impeding cell cycle distribution, and inducing apoptosis. In conclusion, our preliminary results indicated that the combination of MSH6 gene silencing coupled with DDP may have a better effect on the inhibition of OS cell proliferation and promote apoptosis, potentially providing targets for the OS treatment.

Macrophage-derived CCL18 promotes osteosarcoma proliferation and migration by upregulating the expression of UCA1.

Osteosarcoma (OS), which is the most common primary malignant bone tumor, has a high incidence of pulmonary metastasis. CCL18 (C-C motif chemokine ligand 18), which is secreted by tumor-associated macrophages (TAMs), has been found to be increased in various tumors and is associated with tumor metastasis. However, the role of CCL18 in OS remains unclear. Here, we evaluated the effect of CCL18 on the OS cell lines MG63 and 143B and explored its potential mechanisms. We found that CCL18 enhanced the proliferation and migration of OS cells and upregulated UCA1 through transcription factor EP300. Subsequently, we further revealed that the downstream Wnt/β-catenin signaling pathway participated in this process. In addition, the high expression of CCL18 in both tissue and serum from patients was closely related to pulmonary metastasis and poor survival in OS patients. The tumor xenograft models also showed that CCL18 promoted the metastasis of OS cells. Collectively, our study indicated that macrophage-derived CCL18 promotes OS proliferation and metastasis via the EP300/UCA1/Wnt/β-catenin pathway and that CCL18 may be used as a prognostic marker and therapeutic target of OS. KEY MESSAGES: CCL18 promotes proliferation and migration of osteosarcoma cells by EP300/ UCA1/ Wnt/β-catenin pathway. CCL18+ TAMs are significantly correlated with pulmonary metastasis and poor survival in osteosarcoma patients. CCL18 may be used as a prognostic marker and therapeutic target for osteosarcoma.