Human MG-63 Research Articles

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.

Terminal chemical functions of polyamidoamine dendrimer surfaces and its impact on bone cell growth

Besides their use for drug and gene delivery, dendrimer molecules are also favorable for the design of new surface coatings for orthopedic and dental implants due to the wide variety of functional terminal groups and their multivalent character. The purpose of this work was to observe how covalently immobilized polyamidoamine (PAMAM) dendrimer molecules with different terminal chemical groups influenced serum protein adsorption and osteoblast behavior. To this end, fifth-generation PAMAM dendrimers were immobilized on silicon surfaces with an anhydride-containing silane coupling agent which results in positively charged terminal NH2-groups. Coatings with a net negative charge were generated by introduction of terminal CO2H- or CH3-groups. Surface characterization was performed by static and dynamic contact angle and zeta potential. The in vitro studies with human MG-63 osteoblastic cells focused on cell adhesion, morphology, cell cycle, apoptosis and actin formation within 24 h. This work demonstrated that cell growth was dependent on surface chemistry and correlated strongly with the surface free energy and charge of the material. The positively charged NH2 surface induced tight cell attachment with well-organized actin stress fibers and a well spread morphology. In contrast, CO2H- and CH3-functional groups provoked a decrease in cell adhesion and spreading and indicated higher apoptotic potential, although both were hydrophilic. The knowledge about the cell-material dialogue is of relevance for the development of bioactive implants in regenerative medicine.

Cr(VI)-induced genotoxicity and cell cycle arrest in human osteoblast cell line MG-63.

Occupational environments are major exposure routes to Cr(VI). However, Cr(VI) may also establish in bone tissues by ingestion or through Cr containing orthopaedic prostheses that, due to wear and corrosion, may release metal particles and ions potentially affecting bone tissue. The aim of this work was to evaluate the effects of clinically relevant concentrations of Cr(VI) in human osteoblasts, by integrating genotoxic effects, evaluated by the comet assay and cytokinesis-blocked micronucleus assay (scoring the presence of micronucleus, nucleoplasmic bridges and nuclear division index), with the effects on cell cycle and cell viability. Human osteoblasts MG-63 were in vitro exposed to Cr(VI) at concentrations ranging from 0.1 to 5μm, for 24 and 48hours. Results pointed out to a decrease of cell viability for both time exposures in a time- and dose-dependent manner, which was related to cell cycle arrest and DNA damage. Chromosome abnormalities were also observed. Hence, these data suggest that cells arrested in the cell division with DNA damage may have followed cell death pathways, while some surviving ones still revealed DNA damage at chromosome level indicating abnormal cell division progression. In conclusion, Cr(VI) induced cytotoxic and genotoxic effects in human bone cells at concentrations that could be found in patients with metal-on-metal prostheses. In addition, the early onset of genotoxic damage induced by Cr(VI) at low concentrations after 24hours of cell exposure alert to the relevance of periodic monitoring of patients for genotoxicity diagnosis after implantation of prostheses before clinical symptoms appear.

In vitro Comparative Tests About the Biocompatibility of Some Dental Alloys

We evaluated the biocompatibility of four types of commercial alloys (two CoCr alloys and two NiCr alloys) used to make dental bridges. For the cell biology tests, a human osteosarcome type culture cell line MG63 (American Type Culture Collection) was used. Taking into account the results obtained, it can be said that the best results in terms of cell proliferation were observed for the Ni-Cr / Solibond N alloy closely followed by Co-Cr / Heraenium CE, then Co-Cr / Solibond C and Ni-Cr / Kera N, while cell viability tests revealed that the Co-Cr / Heraenium CE alloy exhibits the best biocompatibility, followed by Ni-Cr / Kera N, Co-Cr / Solibond C and Ni-Cr / Solibond N.

Halloysite Nanotube-Reinforced Ion-Incorporated Hydroxyapatite-Chitosan Composite Coating on Ti-6Al-4 V Alloy for Implant Application

To develop the corrosion resistance and improve the biological performance of a titanium implant (Ti6Al4V alloy), a series of mineral (M = Zn and Mg)-substituted hydroxyapatite (MHA), chitosan-MHA (CS-MHA), halloysite nanotube-MHA (HNT-MHA), and HNT-CS-MHA composite coatings were fabricated on the anodized titanium alloy by electrodeposition. The surface morphology and cross section of various coated composites were investigated by high-resolution scanning electron microscopy (HR-SEM). Furthermore, the functional groups and phase structure of the composite coatings were investigated by Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD). Corrosion behaviors of the composite coatings were also investigated by polarization and impedance spectroscopy (EIS). Moreover, the cell-material interaction of the composite coating was observedin vitrowith human osteoblast MG63 cells for cell proliferation at 1, 4, and 7 days of incubation. Consequently, HNT-CS-MHA-Ti may have potential applications in the field of orthopedic and dental implants.

Effect of Calcium Precursor on the Bioactivity and Biocompatibility of Sol-Gel-Derived Glasses.

This study investigated the impact of different calcium reagents on the morphology, composition, bioactivity and biocompatibility of two-component (CaO-SiO2) glasses produced by the Stöber process with respect to their potential application in guided tissue regeneration (GTR) membranes for periodontal repair. The properties of the binary glasses were compared with those of pure silica Stöber particles. The direct addition of calcium chloride (CC), calcium nitrate (CN), calcium methoxide (CM) or calcium ethoxide (CE) at 5 mol % with respect to tetraethyl orthosilicate in the reagent mixture gave rise to textured, micron-sized aggregates rather than monodispersed ~500 nm spheres obtained from the pure silica Stöber synthesis. The broadening of the Si-O-Si band at ~1100 cm−1 in the infrared spectra of the calcium-doped glasses indicated that the silicate network was depolymerised by the incorporation of Ca2+ ions and energy dispersive X-ray analysis revealed that, in all cases, the Ca:Si ratios were significantly lower than the nominal value of 0.05. The distribution of Ca2+ ions was also found to be highly inhomogeneous in the methoxide-derived glass. All samples released soluble silica species on exposure to simulated body fluid, although only calcium-doped glasses exhibited in vitro bioactivity via the formation of hydroxyapatite. The biocompatibilities of model chitosan-glass GTR membranes were assessed using human MG63 osteosarcoma cells and were found to be of the order: CN < pure silica ≈ CC << CM ≈ CE. Calcium nitrate is the most commonly reported precursor for the sol-gel synthesis of bioactive glasses; however, the incomplete removal of nitrate ions during washing compromised the cytocompatibility of the resulting glass. The superior bioactivity and biocompatibility of the alkoxide-derived glasses is attributed to their ease of dissolution and lack of residual toxic anions. Overall, calcium ethoxide was found to be the preferred precursor with respect to extent of calcium-incorporation, homogeneity, bioactivity and biocompatibility.

In vitro evaluation of a novel multiwalled carbon nanotube/nanohydroxyapatite/polycaprolactone composite for bone tissue engineering

Abstract

Theranostics of osteosarcoma and lung metastasis with new integrin α vβ 3 receptor targeted radiotracers

To investigate the value of integrin α vβ 3 targeted microPET/CT imaging with 68Ga-NODAGA-RGD 2 as radiotracer for the detection of osteosarcoma and theranostics of osteosarcoma lung metastasis. The 68Ga-NODAGA-RGD 2 and 177Lu-NODAGA-RGD 2 were prepared via one-step method and their stability and integrin α vβ 3 binding specificity were investigated in vitro. Forty-one nude mice were injected with human MG63 osteosarcoma to established the animal model bearing subcutaneous osteosarcoma ( n=21), osteosarcoma in tibia ( n=5), and osteosarcoma pulmonary metastatic ( n=15). The microPET-CT imaging was carried out in 3 animal models at 1 hour after tail vein injection of 68Ga-NODAGA-RGD 2. Biodistribution study of 68Ga-NODAGA-RGD 2 was performed in animal model bearing subcutaneous osteosarcoma at 10, 60, and 120 minutes. The animal model bearing pulmonary metastatic osteosarcoma was injected with 177Lu-NODAGA-RGD 2 at 7 weeks after model establishment to observe the therapeutic effect of pulmonary metastatic osteosarcoma. Histological and immunohistochemistry examinations were also done to confirm the establishment of animal model and integrin β 3 expression in animal models bearing subcutaneous osteosarcoma and bearing pulmonary metastatic osteosarcoma. 68Ga-NODAGA-RGD 2 and 177Lu-NODAGA-RGD 2 had good stability in vitro with the 50% inhibitory concentration value of (5.0±1.1) and (6.5±0.8) nmol/L, respectively. The radiochemical purity of 68Ga-NODAGA-RGD 2 at 1, 4, and 8 hours was 98.5%±0.3%, 98.3%±0.5%, and 97.9%±0.4%; while the radiochemical purity of 177Lu-NODAGA-RGD 2 at 1, 7, and 14 days was 99.3%±0.7%, 98.7%±1.2%, and 96.0%±2.8%. 68Ga-NODAGA-RGD 2 microPET-CT showed that the accumulation of 68Ga-NODAGA-RGD 2 in animal models bearing subcutaneous osteosarcoma and osteosarcoma in tibia and in lung metastasis as small as 1-2 mm in diameter of animal model bearing pulmonary metastatic osteosarcoma. Biodistribution study of 68Ga-NODAGA-RGD 2 in animal model bearing subcutaneous osteosarcoma revealed rapid clearance from blood with tumor peak uptake of (3.85±0.84) %ID/g at 120 minutes. The distribution of 177Lu-NODAGA-RGD 2 in lung metastasis was similar with 68Ga-NODAGA-RGD 2. The number and size of osteosarcoma metastasis decreased at 2 weeks after 177Lu-NODAGA-RGD 2 administration and integrin targeting specificity was confirmed by pathology examination. 68Ga-NODAGA-RGD 2 was potential for positive imaging and early detection of osteosarcoma and metastasis. Targeted radiotherapy with 177Lu-NODAGA-RGD 2 was one potential alternative for osteosarcoma lung metastasis.

Design, synthesis and biological evaluation of inhibitors of cathepsin K on dedifferentiated chondrocytes.

Selective proteinase inhibitors have demonstrated utility in the investigation of cartilage degeneration mechanisms and may have clinical use in the management of osteoarthritis. The cysteine protease cathepsin K (CatK) is an attractive target for arthritis therapy. Here we report the synthesis of two cathepsin K inhibitors (CKIs): racemic azanitrile derivatives CKI-E and CKI-F, which have better inhibition properties on CatK than the commercial inhibitor odanacatib (ODN). Their IC50 values and inhibition constants (Ki) have been determined in vitro. Inhibitors demonstrate differential selectivity for CatK over cathepsin B, L and S in vitro, with Ki amounting to 1.14 and 7.21 nM respectively. We analyzed the effect of these racemic inhibitors on viability in different cell types. The human osteoblast-like cell line MG63, MOVAS cells (a murine vascular smooth muscle cell line) or murine primary chondrocytes, were treated either with CKI-E or with CKI-F, which were not toxic at doses of up to 5 µM. Primary chondrocytes subjected to several passages were used as a model of phenotypic loss of articular chondrocytes, occurring in osteoarthritic cartilage. The efficiency of CKIs regarding CatK inhibition and their specificity over other proteases were validated in primary chondrocytes subjected to several passages. Racemic CKI-E and CKI-F at 0.1 and 1 µM significantly inhibited CatK activity in dedifferentiated chondrocytes, even better than the commercial CatK inhibitor ODN. The enzymatic activity of other proteases such as matrix metalloproteinases or aggrecanases were not affected. Taken together, these findings support the possibility to design CatK inhibitors for preventing cartilage degradation in different pathologies.

The Effect of Bio-Conditioning of Titanium Implants for Enhancing Osteogenic Activity.

Early and effective integration of titanium-based materials into bone tissue is of vital importance for long-term stability of implants. Surface modification is commonly used to enhance cell-substrate interactions for improving cell adhesion, proliferation, and activity. Here, the surface of titanium substrates and commercial implants were coated with blood (TiB), fetal bovine serum (TiF), and phosphate-buffered saline (TiP) solution using a spin coating process. Surface roughness and wettability of samples were measured using contact angle measurements and atomic force microscopy. The samples were then exposed to human osteoblast-like MG63 cells in order to evaluate adhesion, growth, differentiation, and morphology on the surface of modified samples. Untreated titanium disks were used as controls. The lowest roughness and wettability values were found in unmodified titanium samples followed by TiP, TiF, and TiB. The percentage of cellular attachment and proliferation for each sample was measured using an MTT (3-[4,5-dimethylthiazol-2yl] 2,5diphenyl-2H-tetrazoliumbromide) assay. Cell adhesion and proliferation were most improved on TiB followed closely by TiF. The results of this study revealed an increased expression of the osteogenic marker protein alkaline phosphatase on TiB and the coated commercial titanium implants. These results suggested that precoating titanium samples with blood may improve cellular response by successfully mimicking a physiological environment that could be beneficial for clinical implant procedures.

Electronic cigarette liquid exposure induces flavor-dependent osteotoxicity and increases expression of a key bone marker, collagen type I.

Electronic cigarettes (e-cigarettes) are nicotine delivery devices advertised as a healthier alternative to conventional tobacco products, but their rapid rise in popularity outpaces research on potential health consequences. As conventional tobacco use is a risk factor for osteoporosis, this study examines whether exposure to electronic liquid (e-liquid) used in e-cigarettes affects bone-forming osteoblasts. Human MG-63 and Saos-2 osteoblast-like cells were treated for 48hours with 0.004%-4.0% dilutions of commercially available e-liquids of various flavors with or without nicotine. Changes in cell viability and key osteoblast markers, runt-related transcription factor 2 and Col1a1, were assessed. With all e-liquids tested, cell viability decreased in a dose-dependent manner, which was least pronounced in flavorless e-liquids, most pronounced in cinnamon-flavored e-liquids and occurred independently of nicotine. Col1a1, but not runt-related transcription factor 2, mRNA expression was upregulated in response to coffee-flavored and fruit-flavored e-liquids. Cells treated with a non-cytotoxic concentration of fruit-flavored Mango Blast e-liquid with or without nicotine showed significantly increased collagen type I protein expression compared to culture medium only. We conclude that the degree of osteotoxicity is flavor-dependent and occurs independently of nicotine and that flavored e-liquids reveal collagen type I as a potential target in osteoblasts. This study elucidates potential consequences of e-cigarette use in bone.

Engineering of Bone- and CD44-Dual-Targeting Redox-Sensitive Liposomes for the Treatment of Orthotopic Osteosarcoma.

This study aimed to develop an efficient step-by-step osteosarcoma (OS)-targeting liposome system functionalized with a redox-cleavable, bone- and cluster of differentiation 44 (CD44)-dual-targeting polymer. Furthermore, the effect of coadministration of a tumor-penetrating peptide, internalizing RGD (iRGD), was investigated. First, a bone-targeting moiety, alendronate (ALN), was conjugated with hyaluronic acid (HA), a ligand for CD44. This ALN-HA conjugate was coupled with DSPE-PEG2000-COOH through a bioreducible disulfide linker (-SS-) to obtain a functionalized lipid, ALN-HA-SS-L, to be postinserted into preformed liposomes loaded with doxorubicin (DOX). The roles of ALN, HA, and the redox sensitivity of the ALN-HA-SS-L liposomes (ALN-HA-SS-L-L) in the anti-OS effect were critically evaluated against various reference liposomal formulations (with only ALN, HA, or redox sensitivity). ALN-HA-SS-L-L displayed a zeta potential of -26.07 ± 0.32 mV and selectively disassembled in the presence of a reducing agent, 10 mM glutathione, which can be found in cancer cells. Compared to various reference liposomes, ALN-HA-SS-L-L/DOX had significantly higher cytotoxicity to human OS MG-63 cells alongside high and rapid cellular uptake. In the orthotopic OS nude mouse models, ALN-HA-SS-L-L/DOX showed remarkable tumor growth suppression and prolonged survival time. This result was further improved by the coadministration of iRGD. The antitumor effects of various liposomes were ranked in the same order as the degree of tumor biodistribution shown by in vivo/ex vivo imaging: ALN-HA-SS-L-L coadministered with iRGD > ALN-HA-SS-L-L > HA-SS-L-L > HA-L-L > PEG-L> free drug. ALN-HA-SS-L-L/DOX also reduced the cardiotoxicity of DOX and lung metastases. Overall, this study demonstrated that ALN-HA-SS-L-L/DOX, equipped with bone- and CD44-dual-targeting abilities and redox sensitivity, could be a promising OS-targeted therapy. The efficacy could also be augmented by coadministration of iRGD.

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.

Silver derivatives of multi-donor heterocyclic thioamides as antimicrobial/anticancer agents: unusual bio-activity against methicillin resistant S. aureus, S. epidermidis, and E. faecalis and human bone cancer MG63 cell line.

The basic aim of this study pertains to the synthesis of silver nitrate complexes and the study of their antimicrobial and anticancer bio-activity. A series of new silver(i) derivatives of N-substituted-imidazolidine-2-thiones (L-NR, R = Et, Prn, Bun, Ph), purine-6-thione (purSH2), 2-thiouracil (tucH2), pyrimidine-2-thione (pymSH) and pyridine-2-thione (pySH) of composition [Ag(S-L-NR)(PPh3)2(ONO2)] {R = Et (1), Prn (2), Bun (3), Ph (4)}, [Ag2(N,S-purSH2)2(μ-dppm)2](NO3)2·2H2O (5) (dppm = Ph2P–CH2–PPh2), [Ag(L)(PPh3)2](NO3) {L = N,S-purSH2 (6); S-tucH2 (7)}, [Ag(N,S-pymS)(PPh3)2](CH3OH) (8), and [Ag(N,S-pyS)(PPh3)2] (9) have been synthesized and structurally characterized. These new and some previously reported complexes {[Ag2(L-NH)4(PPh3)2](NO3)2 (10), [Ag(L-NMe)2(PPh3)](NO3) (11), and [Ag(S-bzimSH)2(PPh3)2](OAc) (12), L-NH = 1,3-imidazolidine-2-thione; L-NMe = 1-methyl-3-imidazolidine-2-thione and bzimSH2 = benzimidazoline-2-thione)} have shown moderate to high anti-microbial activity against Gram positive bacteria, namely methicillin resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus (MTCC 740), and Gram negative bacteria, namely Staphylococcus epidermidis (MTCC 435), Enterococcus faecalis (MTCC 439), Shigella flexneri (MTCC 1457) and a yeast Candida albicans (MTCC 22). These complexes have also been found to be bio-safe as studied using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. The anti-tumor study of silver complexes against human osteosarcoma cell line (MG63) has shown IC50 values in the range of 6–33 μM.

A parameterised mathematical model to elucidate osteoblast cell growth in a phosphate-glass microcarrier culture

Tissue engineering has the potential to augment bone grafting. Employing microcarriers as cell-expansion vehicles is a promising bottom-up bone tissue engineering strategy. Here we propose a collaborative approach between experimental work and mathematical modelling to develop protocols for growing microcarrier-based engineered constructs of clinically relevant size. Experiments in 96-well plates characterise cell growth with the model human cell line MG-63 using four phosphate glass microcarrier materials. Three of the materials are doped with 5 mol% TiO2 and contain 0%, 2% or 5% CoO, and the fourth material is doped only with 7% TiO2 (0% CoO). A mathematical model of cell growth is parameterised by finding material-specific growth coefficients through data-fitting against these experiments. The parameterised mathematical model offers more insight into the material performance by comparing culture outcome against clinically relevant criteria: maximising final cell number starting with the lowest cell number in the shortest time frame. Based on this analysis, material 7% TiO2 is identified as the most promising.

Phenotypic stability of the human MG-63 osteoblastic cell line at different passages.

One of the most popular cell lines in osteogenesis studies is the human osteoblastic line MG-63. For cell biological investigation, it is important that the cells remain stable in their phenotype over several passages in cell culture. MG-63 cells can be used to provide fundamental insights into cell--material interaction. The aim of this study is to present a systematic characterization of the physiological behavior of MG-63 cells in the range of passages 5-30. Significant cell physiology processes during the first 24 h, including cell morphology, availability of adhesion receptors, cell cycle phases, as well as the expression of the signaling proteins Akt, GSK3a/b, IkB-α, ERK1/2, p38-MAPK, and intracellular calcium ion mobilization, remained stable over the entire range of passages P5-P30. Due to these stable characteristics in a wide range of cell culture passages, MG-63 cells can be considered as a suitable in vitro model to analyze the biocompatibility and biofunctionality of implant materials.

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.

A Biocompatible Gd&lt;sup&gt;III&lt;/sup&gt;&amp;#x2013;Organic Framework Incorporating Polar Pores for pH-Sensitive Anti-Cancer Drug Delivery and Inhibiting Human Bone Tumour Cells &amp;#x2014; RETRACTED

With the aim of developing new and effective drug delivery systems for cancer treatments, great effort has been devoted to the field of porous metal–organic framework (MOF) platforms because of their controlled drug release performance, high drug loading, and acceptable biocompatibility. In this contribution, we report a MOF [Gd2(H2O)3(SDBA)3](DMA)3] (1, DMA=N,N-dimethylacetamide) with open O donor sites functionalised 1D pores, which has been fabricated using a bent polycarboxylic acid organic linker 4,4′-sulfonyldibenzoic acid (H2SDBA) under solvothermal conditions. Single crystal X-ray diffraction (SCRD), thermogravimetric analysis (TGA), elemental analysis, X-ray powder diffraction (XPRD), and Brunauer–Emmett–Teller (BET) analysis were used to characterise the as-prepared complex 1. 5-Fluorouracil (5-Fu) loaded 1 was soaked in phosphate buffer saline (PBS) and the invitro drug release performance was monitored by HPLC analysis under different pH conditions. At the pH values of 7.4 and 6.5, different profiles of pH-responsive release were achieved, indicating that the drug release performance of 5-Fu loaded 1 is pH sensitive. Grand Canonical Monte Carlo (GCMC) simulation results demonstrate that the open O donor sites in the framework of 1 account for the slower drug release rate. The prepared carrier is found to be bio-compatible with MG63 cells (cancerous tissue) and oral epidermal cells (normal tissue), when tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The 5-Fu loaded carrier also shows a promising growth inhibition effect towards the human bone tumour cells MG63.

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.