Identification of critical genes associated with human osteosarcoma metastasis based on integrated gene expression profiling.

Osteosarcoma is the most common type of malignant bone cancer, which often affects teenagers and young adults. The present study aimed to screen for critical genes and microRNAs (miRNAs/miRs) involved in osteosarcoma. A total of four microarray datasets (accession numbers GSE32981, GSE21257, GSE14827 and GSE14359) were downloaded from the Gene Expression Omnibus database. Following data preprocessing, module analysis was performed to identify the stable modules using the weighted gene co­expression network analysis (WGCNA) package. The differentially expressed genes (DEGs) between metastatic samples and non­metastatic samples were screened, followed by gene co­expression network construction, and Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Subsequently, prognosis­associated genes were screened and a miRNA­target gene regulatory network was constructed. Finally, the data for critical genes were validated. WGCNA analysis identified six modules; blue and yellow modules were significantly positively associated with osteosarcoma metastasis. A total of 1,613 DEGs were screened between primary tissue samples and metastatic samples. Following comparison of the genes in the two (blue and yellow) modules, a total of 166 DEGs were identified (metastatic samples vs. non­metastatic samples). Functional enrichment analysis demonstrated that these DEGs were mainly involved in 'defense response', 'p53 signaling pathway' and 'lysosome'. By utilizing the clinical information in GSE21257, 10 critical genes associated with osteosarcoma prognosis were obtained, including CTP synthase 2 (CTPS2), tumor protein p53 inducible protein 3 (TP53I3) and solute carrier family 1 member 1 (SLC1A1). In addition, hsa­miR­422a and hsa­miR­194 were highlighted in the miRNA­target gene network. Finally, matrix metallopeptidase 3 (MMP3) and vascular endothelial growth factor B (VEGFB) were predicted as critical genes in osteosarcoma metastasis. CTPS2, TP53I3 and SLC1A1 may serve major roles in osteosarcoma development, and hsa­miR­422a, hsa­miR­194, MMP3 and VEGFB may be associated with osteosarcoma metastasis.

Cyclooxygenase-2 expression correlates with development, progression, metastasis, and prognosis of osteosarcoma: a meta-analysis and trial sequential analysis.

Cyclooxygenase-2 (COX-2), a key enzyme in arachidonic acid metabolism, is involved in several cancers, including osteosarcoma. The prognostic significance of COX-2 in osteosarcoma remains controversial. This study was to analyze the potential clinical and prognostic effects of COX-2 protein expression in patients with osteosarcoma. Eligible articles were searched via online databases. The combined odds ratios (ORs) or hazard ratios (HRs) with their 95% confidence intervals (95% CIs) were calculated using the random-effects model. Trial sequential analysis (TSA) was applied to analyze the required information size and determine the reliability of the evidence. Twenty-three studies on COX-2 expression were identified, which included a total of 1084 patients with malignant osteosarcoma and 247 patients with benign osteochondroma. COX-2 protein expression in osteosarcoma was higher than in benign osteochondroma (OR = 7.66, P < 0.001). COX-2 expression was not correlated with age, gender, tumor location, cancer histology, or necrosis (P > 0.1), but was significantly associated with tumor grade (high grade vs. low grade: OR = 4.81, P < 0.001), clinical stage (stage 3-4 vs. stage 1-2: OR = 4.89, P < 0.001), and metastasis (yes vs. no: OR = 3.53, P < 0.001). Based on TSA results, we suggest that additional studies are not required to examine osteosarcoma vs. benign osteochondroma, tumor grade, clinical stage, or metastasis. No heterogeneity was observed in these analyses. COX-2 expression is linked to poor prognosis in metastasis-free survival, overall survival, and relapse-free survival, as indicated by multivariate analysis. Therefore, the expression of COX-2 may correlate with the development, progression, metastasis, and poor prognosis of osteosarcoma.

Ifosfamide-loaded lipid-core-nanocapsules to increase the anticancer efficacy in MG63 osteosarcoma cells.

In this study, we mainly aimed at developing the Ifosfamide-loaded-lipid-core nanocapsules (IFS-LNC) to increase the therapeutic efficacy in osteosarcoma. The nanoparticle was prepared and evaluated in terms of physical, chemical and biological parameters. The lipid-core-nanocapsules were nanosized with narrow particle size distribution and exhibited a high loading capacity. The LNC displayed a sustained release profile of the drug suggesting its potential application in biomedical field and prolonged anticancer therapy. The LNC showed an endocytosis-mediated cellular uptake in MG63 cancer cells which may lead to an accelerated disruption of the acidic endolysosomal vesicles with release of IFS into the cytoplasm. Specifically, IFS-LNC exhibited a significantly higher cytotoxicity than free IFS used at the same concentration. The indiscriminate ability of the drug-loaded formulation increased the apoptosis of cancer cells by increasing the expression levels of caspase-3 and caspase-9 in MG63 cells. Overall, nanoparticulate formulations of Ifosfamide enhanced the therapeutic efficacy in osteosarcoma.

Computational Exploration of Natural Compounds to Target Cytosolic Phospholipase A 2 Protein: A Novel Therapeutic Target for Spinal Cord Injury.

BACKGROUND: Cytosolic Phospholipase A2 (cPLA2), an important isoform of PLA2 that mediates the release of arachidonic acid, plays a role in the pathogenesis of Spinal Cord Injury (SCI). The expression and activation of Cpla2 are significantly higher in SCI, leading to neuronal death in spinal cord tissue. Novel strategies are needed to substantially reverse the effect of cPLA2 activation; one such strategy is inhibiting cPLA2 by jamming its lipid binding C2 domain. OBJECTIVE: To develop a much needed strategy to treat SCI, we used a Computer Aided Drug Design (CADD) method to discover novel cPLA2 inhibitors. METHODS: we used a natural chemiome database for virtual screening, from which we selected the compounds exhibiting the greatest drug-likeliness properties for molecular docking simulation analysis. RESULTS: We studied the interaction of lead compounds at the atomic level; the results yielded a cPLA2 inhibitor of natural origin with the potential for ameliorating secondary tissue damage and promoting recovery of function after SCI. The top compound, lead 4exibited a binding energy of -10.02 Kcal/mol and formed three hydrogen bonds with the lipid binding C2 domain of the cPLA2 protein. An evaluation of cell cytotoxicity revealed an IC50 for lead4 of 134.2 ± 6.8 µM. An in-vitro analysis of lead4 is indicated anti-apoptotic activity via a decrease in caspase-3 expression. CONCLUSION: We used the CADD method to make a novel lead discovery for the treatment of SCI using compounds of natural origin. The selected natural compounds are non-toxic promising drugs against cPLA2 protein, allowing us to limits our focus on single compound for future in-vitro and invivo testing.

A Study to Assess the Accuracy of Adductor Tubercle as a Reliable Landmark Used to Determine the Joint Line of the Knee in a Chinese Population.

BACKGROUND: Restoring the joint line (JL) is a key element of performing joint arthroplasty, which is a challenging proposition during revision surgeries. We investigated the accuracy of 2 different methods of identifying the JL using the adductor tubercle (AT) as the reference landmark. METHODS: Standardized protocols for measurements from 50 knee radiographs were established. Femoral width (FW) and the distance from the AT to the JL (ATJL) were measured on anteroposterior radiographs, and the femoral diameter (FD) was measured on true lateral views. The individual ratio of FW and FD to ATJL was calculated using linear regression analysis. Intraobserver and interobserver reliability was assessed. In order to test the accuracy of the ratio calculated, we also recorded the FW and ATJL of 20 additional knees by magnetic resonance images. RESULTS: There are significant differences between genders with these parameters. A linear correlation was found between FW and ATJL (r2 = 0.7201), which was more reliable than the correlation between FD and ATJL (r2 = 0.3918). Interobserver repeatability was better for ATJL and FW than for FD. The mean ratio of ATJL/FW was 0.560 ± 0.03, and there was no statistical difference between men and women. After using this ratio formulas in those data measured from knee magnetic resonance imaging, all cases revealed reliability with 100% cases lying in a 4-mm error margin. CONCLUSION: The AT can be used as a reliable landmark to determine the knee JL position, and the formulas for calculating the ATJL with FW can be applied, making intraoperative identification and judgment easier.

[An anatomic study of glenoid regarding anchor insertion posion and direction].

OBJECTIVE: To investigate normal bony anatomy of the glenoid rim, to measure inner glenoid rim angle and outer glenoid rim angle, and the angles for successful anchor insertion for arthroscopic labral repairs. METHODS: Twelve unpaired isolated human glenoids (6 right, 6 left) without any evidence of trauma were for studying. The glenoid specimens were scanned using 320-slice CT (Aquilion ONE), then reconstruction glenoid to a three dimensional model using materialise's interactive medical image control system (Mimics) and to obtain cross-sectional images in 6 different planes, mark the right glenoid rim with clockwise tag, the left with counterclockwise tag. Inner glenoid rim angle marked as angle α and outer glenoid rim angle marked as angle ß were measured from the cross-sectional images of the glenoids at 8 positions: 2-, 3-, 4-, 5-, 6-, 7-, 8- and 9-o'clock positions. Glenoid morphology was noted for each position. Using 12 mm as radius, measured the minimum insertion angle of anchor, marked as angle γ. Normal distribution of the data was confirmed with Kolmogorov-Smirnov test. Paired t-test was performed to detect differences in the angles between two locations. Two independent samples t-test was performed to detect differences in the angles between same location of left and right. Analysis of variance (ANOVA) was performed to detect differences in the angles between right and left, and different locations of the glenoid rim. RESULTS: The smallest α was at the 4-o'clock position (right 50° ± 6°, left 52° ± 9°), significant difference were seen when compared with the 6-o'clock position (t = 10.466, P = 0.000) or the 5-o'clock position (t = 3.754, P = 0.003), no significant difference exist between 4-o'clock position and 3-o'clock posion (t = 0.926, P = 0.374). The smallest ß was at the 3-o'clock position (right 50° ± 6°, left 53° ± 10°), significant difference were seen when compared with the 6-o'clock position (t = 9.862, P = 0.000) or the 5-o'clock position (t = 3.634, P = 0.003), no significant difference exist between 4-o'clock position and 3-o'clock posion (t = 0.697, P = 0.501). Asymmetric morphology of the glenoid was noted with an almost straight line extending medially from the rim at the 3-o'clock position, whereas a concave morthology was noted at the 9-o'clock position. Similary at the 4- and 5-o'clock position, the scapular bony surface did not curve toward the base as markedly as it did at the corresponding posterior 8- and 7-o'clock position. Angle γ from the 3-o'clock to the 9-o'clock were 25° ± 4°, 54° ± 6°, 83° ± 4°, 119° ± 2° at right side, 23° ± 4°, 57° ± 4°, 89° ± 7°, 119° ± 4° at left side. No significant difference of any angle at the same position was noted between left and right (α:t = 0.283-1.785, P > 0.05;ß:t = 0.369-2.067, P > 0.05;γ:t = 0.145-0.492, P > 0.05). CONCLUSIONS: The available bone mass for the anchor insertion is found to vary depending on the position of the glenoid rim. The smallest inner and outer glenoid rim angle are at the 4- and 3-o'clock position. The minimum insertion angles of anchor differ at different position. Both rim angle and glenoid morthology for each position must be considered when selecting the ideal anchor insertion angle for Bankart repair. Meanwhile, minimum insertion angle of anchor should also be considered before anchor insertion.

Probing adsorption of polyacrylamide-based polymers on anisotropic Basal planes of kaolinite using quartz crystal microbalance.

Quartz crystal microbalance with dissipation (QCM-D) was applied to investigate the adsorption characteristics of polyacrylamide-based polymers (PAMs) on anisotropic basal planes of kaolinite. Kaolinite basal planes were differentiated by depositing kaolinite nanoparticles (KNPs) on silica and alumina sensors in solutions of controlled pH values. Adsorption of an in-house synthesized organic-inorganic Al(OH)3-PAM (Al-PAM) as an example of cationic hybrid PAM and a commercially available partially hydrolyzed polyacrylamide (MF1011) as an example of anionic PAM was studied. Cationic Al-PAM was found to adsorb irreversibly and preferentially on tetrahedral silica basal planes of kaolinite. In contrast, anionic MF1011 adsorbed strongly on aluminum-hydroxy basal planes, while its adsorption on tetrahedral silica basal planes was weak and reversible. Adsorption study revealed that both electrostatic attraction and hydrogen-bonding mechanisms contribute to adsorption of PAMs on kaolinite. The adsorbed Al-PAM layer was able to release trapped water overtime and became more compact, while MF1011 film became more dissipative as backbones stretched out from kaolinite surface with minimal overlapping. Experimental results obtained from this study provide clear insights into the phenomenon that governs flocculation-based solid-liquid separation processes using multicomponent flocculants of anionic and cationic nature.

Mechanistic study on demulsification of water-in-diluted bitumen emulsions by ethylcellulose.

In our previous study, ethylcellulose (EC), an effective, nontoxic, and biodegradable natural polymer, was found effective in dewatering water-in-diluted bitumen emulsions. In this study, the demulsification mechanism of water-in-diluted bitumen emulsions by EC is investigated. In situ experiments using a micropipet apparatus provided direct evidence on both flocculation and coalescence of water droplets in diluted bitumen by EC. The addition of EC was found to decrease naphtha-diluted bitumen-water interfacial tension significantly. At the molecular level, AFM imaging revealed disruption of the continuous interfacial films formed from surface-active components of bitumen by EC. Our study clearly indicates that the demulsification by EC is through both flocculation and coalescence of water droplets, attained by competitive adsorption of EC at the oil-water interface and disruption of the original protective interfacial films formed from the surface-active components of bitumen.

Interaction forces between asphaltene surfaces in organic solvents.

The colloidal interactions between asphaltene surfaces in heptol, a mixture of n-heptane and toluene, were studied for the first time by colloidal force measurements using an atomic force microscope (AFM). Asphaltenes were deposited on silica wafers and silica spheres using the Langmuir-Blodgett upstroke technique. The results showed that the ratio of toluene to heptane can significantly change solvent quality in terms of the ability to solubilize asphaltenes and hence the nature and the magnitude of the interaction forces between asphaltene surfaces. In pure toluene, there is a steric long-range repulsion which can be well fitted by the scaling theory of polymer brushes. As toluene volume fraction in heptol (Phi(T)) is gradually decreased from Phi(T) = 1 (pure toluene) to Phi(T) = 0 (pure n-heptane), the steric repulsion reduced and changed to weak attraction when Phi(T) < 0.2. The attraction in heptane can be fitted by van der Waals forces alone which are thus believed to promote asphaltene aggregation, leading to asphaltene precipitation. The results obtained in this study provide an insight into interactions that determine asphaltene behavior in an organic medium and hence in crude oils.