CircDOCK1 promotes the tumorigenesis and cisplatin resistance of osteogenic sarcoma via the miR-339-3p/IGF1R axis

Background Circular RNAs (circRNAs), a class of noncoding RNAs (ncRNAs), may modulate gene expression by binding to miRNAs. Additionally, recent studies show that circRNAs participate in some pathological processes. However, there is a large gap in the knowledge about circDOCK1 expression and its biological functions in osteogenic sarcoma (OS). Methods Differentially expressed circRNAs in OS cell lines and tissues were identified by circRNA microarray analysis and quantitative real-time PCR (qRT–PCR). To explore the actions of circDOCK1 in vivo and in vitro, circDOCK1 was knocked down or overexpressed. To assess the binding and regulatory associations among miR-339-3p, circDOCK1 and IGF1R, we performed rescue experiments, RNA immunoprecipitation (RIP), RNA pulldown assays and dual-luciferase assays. Moreover, we performed apoptosis assays to reveal the regulatory effects of the circDOCK1/miR-339-3p/IGF1R axis on cisplatin sensitivity. Results CircDOCK1 expression remained stable in the cytoplasm and was higher in OS tissues and cells than in the corresponding controls. Overexpression of circDOCK1 increased oncogenicity in vivo and malignant transformation in vitro. In the U2OS and MG63 cell lines, circDOCK1 modulated tumor progression by regulating IGF1R through sponging of miR-339-3p. Additionally, in the U2OS/DDP and MG63/DDP cell lines, cisplatin sensitivity was regulated by circDOCK1 via the miR-339-3p/IGF1R axis. Conclusions CircDOCK1 can promote progression and regulate cisplatin sensitivity in OS via the miR-339-3p/IGF1R axis. Thus, the circDOCK1/miR-339-3p/IGF1R axis may be a key mechanism and therapeutic target in OS.

Effect of Extreme Ultraviolet (EUV) Radiation and EUV Induced, N2 and O2 Based Plasmas on a PEEK Surface’s Physico-Chemical Properties and MG63 Cell Adhesion

Polyetheretherketone (PEEK), due to its excellent mechanical and physico-chemical parameters, is an attractive substitute for hard tissues in orthopedic applications. However, PEEK is hydrophobic and lacks surface-active functional groups promoting cell adhesion. Therefore, the PEEK surface must be modified in order to improve its cytocompatibility. In this work, extreme ultraviolet (EUV) radiation and two low-temperature, EUV induced, oxygen and nitrogen plasmas were used for surface modification of polyetheretherketone. Polymer samples were irradiated with 100, 150, and 200 pulses at a 10 Hz repetition rate. The physical and chemical properties of EUV and plasma modified PEEK surfaces, such as changes of the surface topography, chemical composition, and wettability, were examined using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and goniometry. The human osteoblast-like MG63 cells were used for the analysis of cell viability and cell adhesion on all modified PEEK surfaces. EUV radiation and two types of plasma treatment led to significant changes in surface topography of PEEK, increasing surface roughness and formation of conical structures. Additionally, significant changes in the chemical composition were found and were manifested with the appearance of new functional groups, incorporation of nitrogen atoms up to ~12.3 at.% (when modified in the presence of nitrogen), and doubling the oxygen content up to ~25.7 at.% (when modified in the presence of oxygen), compared to non-modified PEEK. All chemically and physically changed surfaces demonstrated cyto-compatible and non-cytotoxic properties, an enhancement of MG63 cell adhesion was also observed.

Anti-proliferative effects of Euphorbia hirta L on the activity of cytotoxicity in bone cancer MG-63 cells

Medicinal plants maintain the health and vitality of individuals, and also have potential curative effect on various diseases, including cancer. Bone cancer is the foremost cause of deaths among women worldwide. In this present study, the antiproliferative effects of methanol extracts of Euphorbia hirta L leaves was investigated on MG 63 cell line. The methanolic extract of plant exhibited significant dose dependent antiproliferative activity against MG63 cell line which was ranged between 89.43% and 20.63% at concentrations of 50µg/ml and 350µg/ml correspondingly (24 hours). Moreover, the plant found to decrease the cell viability in dose dependent manner. The results of this study show that Euphorbia hirta L is a potential source of compounds that may serve as leads for anticancer property.

Advances in Laser Additive Manufacturing of Ti-Nb Alloys: From Nanostructured Powders to Bulk Objects

The additive manufacturing of low elastic modulus alloys that have a certain level of porosity for biomedical needs is a growing area of research. Here, we show the results of manufacturing of porous and dense samples by a laser powder bed fusion (LPBF) of Ti-Nb alloy, using two distinctive fusion strategies. The nanostructured Ti-Nb alloy powders were produced by mechanical alloying and have a nanostructured state with nanosized grains up to 90 nm. The manufactured porous samples have pronounced open porosity and advanced roughness, contrary to dense samples with a relatively smooth surface profile. The structure of both types of samples after LPBF is formed by uniaxial grains having micro- and nanosized features. The inner structure of the porous samples is comprised of an open interconnected system of pores. The volume fraction of isolated porosity is 2 vol. % and the total porosity is 20 vol. %. Cell viability was assessed in vitro for 3 and 7 days using the MG63 cell line. With longer culture periods, cells showed an increased cell density over the entire surface of a porous Ti-Nb sample. Both types of samples are not cytotoxic and could be used for further in vivo studies.

Preparation of a Fucoidan-Grafted Hyaluronan Composite Hydrogel for the Induction of Osteoblast Differentiation in Osteoblast-Like Cells

A suitable bone substitute is necessary in bone regenerative medicine. Hyaluronan (HA) has excellent biocompatibility and biodegradability and is widely used in tissue engineering. Additionally, research on fucoidan (Fu), a fucose- and sulfate-rich polysaccharide from brown seaweed, for the promotion of bone osteogenic differentiation has increased exponentially. In this study, HA and Fu were functionalized by grafting methacrylic groups onto the backbone of the chain. Methacrylate-hyaluronan (MHA) and methacrylate-fucoidan (MFu) were characterized by FTIR and 1H NMR spectroscopy to confirm functionalization. The degrees of methacrylation (DMs) of MHA and MFu were 9.2% and 98.6%, respectively. Furthermore, we evaluated the mechanical properties of the hydrogels formed from mixtures of photo-crosslinkable MHA (1%) with varying concentrations of MFu (0%, 0.5%, and 1%). There were no changes in the hardness values of the hydrogels, but the elastic modulus decreased upon the addition of MFu, and these mechanical properties were not significantly different with or without preosteoblastic MG63 cell culture for up to 28 days. Furthermore, the cell morphologies and viabilities were not significantly different after culture with the MHA, MHA-MFu0.5, or MHA-MFu1.0 hydrogels, but the specific activity and mineralization of alkaline phosphatase (ALP) were significantly higher in the MHA-MFu1.0 hydrogel group compared to the other hydrogels. Hence, MHA-MFu composite hydrogels are potential bone graft materials that can provide a flexible structure and favorable niche for inducing bone osteogenic differentiation.

LncRNA STK4 antisense RNA 1(STK4-AS1) affects the osteosarcoma cell cycle by regulating p53 protein

Background: LncRNA STK4-AS1 has been identified as a potential biomarker associated with multiple cancers. We proposed that STK4-AS1 plays a role in the proliferation of osteosarcoma by regulating its cell cycle. Methods: We compared the expression of STK4-AS1 in osteosarcoma vs normal samples both in clinical tissues and cell lines. We overexpressed and knockdown STK4-AS1 in p53 expressing osteosarcoma cells U2OS and p53 muted expressing osteosarcoma cells MG63 and analyzed cell viability and cell cycle. We overexpressed p53 in STK4-AS1 knockdown cells to explore the association of STK4-AS1 and p53 in the cell cycle. Results: The STK4-AS1 expression was higher in osteosarcoma tissue than adjacent normal bone tissues and was higher in osteosarcoma cell lines (U2OS, MG63, and SAOS-2) than in osteoblast cell lines (hFOB and HOB). Knockdown of STK4-AS1 in U2OS decreased the cell viability, increased cells in the G0/G1 phase, decreased cells in the S and G2/M phase, decreased expression of cyclin A and B, increased p53 and p21, and had no effect on cyclin D and cyclin E, while overexpression did the opposes. MG63 cell viability was not affected by altered STK4-AS1 levels. P53 overexpression in STK4-AS1 knockdown cells recovered cell viability, p21, cyclin A, and cyclin B expression. Conclusion: LncRNA STK4-AS1 affected p53 expressing osteosarcoma cells U2OS cell viability through regulating cell cycle, which is mediated by p53/p21 pathway.

11-O-Galloyl Bergenin from Corylopsis coreanas Leaves Induces Autophagy and Apoptosis in Human Osteosarcoma

Osteosarcoma is the most common malignant bone-forming tumor, wherein most patients with high grade osteosarcomas are treated with chemotherapy. Despite this, survival for metastatic or relapsed osteosarcoma patients has remained at an overall 5-year survival rate of 20%. In particular, the extracts of Corylopsis coreana (Korean winter hazel), a cultivated woody plant in South Korea, have shown beneficial anti-inflammatory, anti-oxidative, anti-osteoclastic, and antihyperuricemic properties. Therefore, this study aimed to demonstrate the antitumor activities and underlying mechanism of 11-O-Galloyl bergenin (OGAL) isolated from Corylopsis coreanas leaves in human osteosarcoma cells. Herein, we found that OGAL inhibited MG63 cell proliferation and induced cellular apoptosis as evidenced by cleaved-PARP, cleaved-caspase 3, TUNEL-positive cells, and Annexin V-positive cells. Specifically, OGAL-induced apoptosis was accompanied by p53 and p21 upregulation, BAX expression, and decreased Bcl-2 and cdk2. Moreover, OGAL induced autophagy via AKT inactivation, LC3II upregulation, and MG63 cell autophagosome formation. OGAL-induced autophagy was also accompanied by increased p38 phosphorylation, whereas JNK and ERK1/2 activities were found to be unaffected upon examining the MAPK signaling pathway. Furthermore, wound healing and Boyden chamber assays showed that OGAL suppressed MG63 cell migration and invasion. Given these findings, this study provided evidence that OGAL has antitumor effects by apoptosis and autophagy enhancement through increased p53, AKT, and p38 signaling, suggesting that OGAL may be a potential therapeutic strategy for osteosarcoma treatment.

Characterization and in vitro cytotoxicity evaluation of fish scale and seashell derived nano-hydroxyapatite high-density polyethylene composite

Hydroxyapatite (HAp) is the major inorganic component of natural bone which exhibits better biocompatibility with various kinds of cells and tissues, making it an ideal candidate for dental and orthopedic applications. The naturally extracted HAp (Ca10(PO4)6(OH)2) from fish scale and seashell is exactly matched with the chemical composition of bone minerals. Nowadays, soft chemistry is used for the synthesis of bioceramics such as HAp. This is a chemical route that yields more homogeneous solid-state materials. In this study, the extracted powder from fish scale and seashell was heated in the furnace and maintained at 700°C for 3 hours and the powder was naturally cooled. The derived CaO was used for preparing HAp by the microwave irradiation techniques. The HAp was filled with High-Density Polyethylene (HDPE) in the ratio of 10:3 (Matrix 100 g: Filler 30 g) and composite was fabricated by the injection molding. The functional groups present in the HAp-HDPE specimen was identified using Fourier Transform Infrared (FTIR) spectroscopy analysis. The thermal stability of 30 wt. % HAp-HDPE composite was analyzed using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). In vitro cytotoxicity studies were carried out using MG63 cell line. In these studies, five different volumes of liquid extracts of the prepared HAp-HDPE specimen having different concentrations (10, 20, 30, 40, and 50 μl) were allowed to interact with fresh cell culture medium for 24 hours. The cell morphology, cell viability, and the levels of cytotoxicity of the composite specimen were studied as per 10993:12, and ISO 10993:5 test standards.

Identification of Driver Genes and Key Pathways of Osteosarcoma Shows K-7174 As a Novel Anti-osteosarcoma Drug by Inhibiting VCAM1

BackgroundOsteosarcoma is one of the leading causes in cancer-related death of children and adolescents. However current standard therapeutic strategy, surgery combined with neoadjuvant chemotherapy is very limited in effects. As big data mining and analysis using bioinformatics method has been applied in the diagnosis and treatment of many cancers, we want to use bioinformatic combined with experimental assays to found new molecular targets and test new drug for osteosarcoma.MethodsThe gene chip of osteosarcoma samples constructed by Richter GH et al were downloaded from the Gene Expression Omnibus (GEO) database, Gene Ontology analysis (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed on differential expression genes which screened by bioinformatics methods.Protein-protein interaction network was constructed by suing STRING database to found hub gene. Combined with pertinent literature, genes of interest and corresponding drug was selected. Series of experiments were performed on the osteosarcoma cell lines in vitro, involved cell viability test, colony formation assay, migratory and invasive tests, western blot as well.ResultsA total of 1069 DEGs were obtained from data, including 375 up-regulated genes and 694 down-regulated genes. Differentially expressed genes mainly involve biological processes such as cellular immune function, such as interferon-gamma-mediated signaling pathway and antigen processing and presentation of peptide. Among top 20-ranked degree hug gene evaluated by PPI network, vascular cell adhesion molecule-1(VCAM1) was picked out. An VCAM1 inhibitor K-7174 was treated in U2OS and MG63 cell lines. In vitro experiments have shown that K-7174 can inhibit the proliferation, migration and invasion of osteosarcoma, the protein expression of VCAM1was also decreased by K-7174.ConclusionsVCAM1 could be a potential target for osteosarcoma and K-7174 promises to be a therapeutic drug after more nuanced evaluation in animal and clinical trials.