Comparative proteome analysis of monolayer and spheroid culture of canine osteosarcoma cells

Proteomic Analyses Reveal the Role of Alpha-2-Macroglobulin in Canine Osteosarcoma Cell Migration

Canine osteosarcoma (OSA) is an aggressive bone neoplasia with high metastatic potential. Metastasis is the main cause of death associated with OSA, and there is no current treatment available for metastatic disease. Proteomic analyses, including matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI TOF/TOF MS), are widely used to select molecular targets and identify proteins that may play a key role in primary tumours and at various steps of the metastatic cascade. The main aim of this study was to identify proteins differently expressed in canine OSA cell lines with different malignancy phenotypes (OSCA-8 and OSCA-32) compared to canine osteoblasts (CnOb). The intermediate aim of the study was to compare canine OSA cell migration capacity and assess its correlation with the malignancy phenotypes of each cell line. Using MALDI-TOF/TOF MS analyses, we identified eight proteins that were significantly differentially expressed (p ≤ 0.05) in canine OSA cell lines compared to CnOb: cilia- and flagella-associated protein 298 (CFAP298), general transcription factor II-I (GTF2I), mirror-image polydactyly gene 1 protein (MIPOL1), alpha-2 macroglobulin (A2M), phosphoglycerate mutase 1 (PGAM1), ubiquitin (UB2L6), ectodysplasin-A receptor-associated adapter protein (EDARADD), and leucine-rich-repeat-containing protein 72 (LRRC72). Using the Simple Western technique, we confirmed high A2M expression in CnOb compared to OSCA-8 and OSCA-32 cell lines (with intermediate and low A2M expression, respectively). Then, we confirmed the role of A2M in cancer cell migration by demonstrating significantly inhibited OSA cell migration by treatment with A2M (both at 10 and 30 mM concentrations after 12 and 24 h) in a wound-healing assay. This study may be the first report indicating A2M's role in OSA cell metastasis; however, further in vitro and in vivo studies are needed to confirm its possible role as an anti-metastatic agent in this malignancy.

Enhanced Biomimetics of Three-Dimensional Osteosarcoma Models: A Scoping Review

This scoping review evaluated 3D osteosarcoma (OS) models' biomimicry, examining their ability to mimic the tumour microenvironment (TME) and their drug sensitivity. Adhering to PRISMA-ScR guidelines, the systematic search revealed 293 studies, with 70 selected for final analysis. Overall, 64% of 3D OS models were scaffold-based, compared to self-generated spheroid models. Scaffolds generated using native matrix were most common (42%) with collagen I/hydroxyapatite predominating. Both scaffold-based and scaffold-free models were used equally for drug screening. The sensitivity of cancer cells in 3D was reported to be lower than that of cells in 2D in ~90% of the drug screening studies. This correlates with the observed upregulation of drug resistance. OS cells cultured in extracellular matrix (ECM)-mimetic scaffolds and native biomaterials were more resistant than cells in 2D. Co-cultures of OS and stromal cells in 3D models enhanced osteogenic differentiation, ECM remodelling, mineralisation, and angiogenesis, suggesting that tumour-stroma crosstalk promotes disease progression. Seven studies demonstrated selective toxicity of chemotherapeutics towards OS cells while sparing stromal cells, providing useful evidence for developing biomimetic tumour-stroma models to test selective drug toxicity. In conclusion, this review highlights the need to enhance biomimicry in 3D OS models for TME recapitulation, especially in testing novel therapeutics. Future research should explore innovative 3D biomimetic models, biomaterials, and advancements in personalised medicine.

Chemokine Ligand 2 Promotes Migration in Osteosarcoma by Regulating the miR-3659/MMP-3 Axis

Osteosarcoma is a common malignant tumor in children and adolescents, known for its aggressive invasion and distant metastasis, leading to a poor prognosis. Matrix metalloproteinases (MMPs) can degrade the extracellular matrix and basement membranes through their proteolytic activity, thereby promoting osteosarcoma metastasis. Chemokine ligand 2 (CCL2) is a well-studied chemokine that plays a significant role in the cell motility of many cancers. However, its specific involvement in osteosarcoma metastasis is not fully understood. The aim of this study is to examine the role of miRNAs in CCL2-mediated MMP expression and cell motility in human osteosarcoma. The analysis of immunohistochemistry data and databases associated a positive correlation between CCL2 or MMP-3 levels with the metastasis of osteosarcoma patients. The in vivo lung metastatic osteosarcoma model also demonstrated similar effects, showing higher levels of CCL2 and MMP-3 in lung metastatic osteosarcoma tissues. The stimulation of osteosarcoma cells with CCL2 enhanced migration and invasion abilities through the upregulation of MMP-3 synthesis. Our results also indicate that CCL2 enhances MMP-3-dependent cell motility by inhibiting miR-3659 synthesis. Therefore, CCL2 represents a promising therapeutic target for treating metastasis in osteosarcoma.

Gold Nanoparticles Inhibit Extravasation of Canine Osteosarcoma Cells in the Ex Ovo Chicken Embryo Chorioallantoic Membrane Model

Canine osteosarcoma (OS) is an aggressive bone tumor with high metastatic potential and poor prognosis, mainly due to metastatic disease. Nanomedicine-based agents can be used to improve both primary and metastatic tumor treatment. Recently, gold nanoparticles were shown to inhibit different stages of the metastatic cascade in various human cancers. Here, we assessed the potential inhibitory effect of the glutathione-stabilized gold nanoparticles (Au-GSH NPs) on canine OS cells extravasation, utilizing the ex ovo chick embryo chorioallantoic membrane (CAM) model. The calculation of cells extravasation rates was performed using wide-field fluorescent microscopy. Transmission electron microscopy and Microwave Plasma Atomic Emission Spectroscopy revealed Au-GSH NPs absorption by OS cells. We demonstrated that Au-GSH NPs are non-toxic and significantly inhibit canine OS cells extravasation rates, regardless of their aggressiveness phenotype. The results indicate that Au-GSH NPs can act as a possible anti metastatic agent for OS treatment. Furthermore, the implemented CAM model may be used as a valuable preclinical platform in veterinary medicine, such as testing anti-metastatic agents.

The Double-Edged Proteins in Cancer Proteomes and the Generation of Induced Tumor-Suppressing Cells (iTSCs)

Unlike a prevalent expectation that tumor cells secrete tumor-promoting proteins and stimulate the progression of neighboring tumor cells, accumulating evidence indicates that the role of tumor-secreted proteins is double-edged and context-dependent. Some of the oncogenic proteins in the cytoplasm and cell membranes, which are considered to promote the proliferation and migration of tumor cells, may inversely act as tumor-suppressing proteins in the extracellular domain. Furthermore, the action of tumor-secreted proteins by aggressive "super-fit" tumor cells can be different from those derived from "less-fit" tumor cells. Tumor cells that are exposed to chemotherapeutic agents could alter their secretory proteomes. Super-fit tumor cells tend to secrete tumor-suppressing proteins, while less-fit or chemotherapeutic agent-treated tumor cells may secrete tumor-promotive proteomes. Interestingly, proteomes derived from nontumor cells such as mesenchymal stem cells and peripheral blood mononuclear cells mostly share common features with tumor cell-derived proteomes in response to certain signals. This review introduces the double-sided functions of tumor-secreted proteins and describes the proposed underlying mechanism, which would possibly be based on cell competition.

Exposure of intestinal explants to NX, but not to DON, enriches the secretome in mitochondrial proteins

NX is a type A trichothecene produced by Fusarium graminearum with limited information on its toxicity. NX is structurally similar to deoxynivalenol (DON), only differing by the lacking keto group at C8. Because of the structural similarity of the two toxins as well as their potential co-occurrence in food and feed, it is of interest to determine the toxicity of this new compound. In this study, we compared the protein composition of the extracellular media of pig intestinal explants (secretome) exposed to 10 µM of DON or NX for 4 h compared with controls. The combination of two complementary quantitative proteomic approaches (a gel-based and a gel-free approach) identified 18 and 23 differentially abundant proteins (DAPs) for DON and NX, respectively, compared to controls. Functional analysis suggested that, whereas DON toxicity was associated with decreased cell viability and cell destruction, NX toxicity was associated with an enrichment of mitochondrial proteins in the secretome. The presence of these proteins may be associated with the already known ability of NX to induce an intestinal inflammation. Overall, our results indicated that DON- and NX-induced changes in the extracellular proteome of intestinal explants are different. The increased leakage/secretion of mitochondrial proteins by NX may be a feature of NX toxicity.

Defucosylated Anti-Epidermal Growth Factor Receptor Monoclonal Antibody (134-mG2a-f) Exerts Antitumor Activities in Mouse Xenograft Models of Canine Osteosarcoma

The epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein. Although EGFR is physiologically essential in normal cells, it contributes to tumor malignancy through gene amplification and/or protein overexpression, which augment signaling cascades in tumor cells. We previously developed an anti-human EGFR (hEGFR) monoclonal antibody (mAb), EMab-134 (mouse IgG₁, kappa), which detects hEGFR and dog EGFR (dEGFR) with high sensitivity and specificity. The mouse IgG_2a version of EMab-134 (134-mG_2a) has antitumor effects toward mouse xenografts of hEGFR-expressing oral squamous cell carcinomas. Furthermore, 134-mG_2a-f, the defucosylated version of 134-mG_2a, exhibits antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) in dEGFR-overexpressed CHO-K1 (CHO/dEGFR) cells and antitumor activities in mouse xenografts of CHO/dEGFR cells. Herein, the reactivity of 134-mG_2a-f against canine cancer cells with endogenous dEGFR was first examined by flow cytometry and immunocytochemistry. In vitro analysis demonstrated that 134-mG_2a-f highly exerted ADCC and CDC for a canine osteosarcoma cell line, D-17, which expresses endogenous dEGFR. Moreover, in vivo administration of 134-mG_2a-f significantly suppressed the development of D-17 compared with the results in response to control mouse IgG. These results suggest that 134-mG_2a-f exerts antitumor effects against dEGFR-expressing canine cancers, and could be valuable as part of an antibody treatment regimen for them.

Defucosylated Mouse-Dog Chimeric Anti-EGFR Antibody Exerts Antitumor Activities in Mouse Xenograft Models of Canine Tumors

The epidermal growth factor receptor (EGFR) contributes to tumor malignancy via gene amplification and protein overexpression. Previously, we developed an anti-human EGFR (hEGFR) monoclonal antibody, namely EMab-134, which detects hEGFR and dog EGFR (dEGFR) with high sensitivity and specificity. In this study, we produced a defucosylated mouse–dog chimeric anti-EGFR monoclonal antibody, namely E134Bf. In vitro analysis revealed that E134Bf highly exerted antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity against a canine osteosarcoma cell line (D-17) and a canine fibroblastic cell line (A-72), both of which express endogenous dEGFR. Moreover, in vivo administration of E134Bf significantly suppressed the development of D-17 and A-72 compared with the control dog IgG in mouse xenografts. These results indicate that E134Bf exerts antitumor effects against dEGFR-expressing canine cancers and could be valuable as part of an antibody treatment regimen for dogs.

Proteomic and electron microscopy study of myogenic differentiation of alveolar mucosa multipotent mesenchymal stromal cells in three-dimensional culture

Myocyte differentiation is featured by adaptation processes, including mitochondria repopulation and cytoskeleton re-organization. The difference between monolayer and spheroid cultured cells at the proteomic level is uncertain. We cultivated alveolar mucosa multipotent mesenchymal stromal cells in spheroids in a myogenic way for the proper conditioning of ECM architecture and cell morphology, which induced spontaneous myogenic differentiation of cells within spheroids. Electron microscopy analysis was used for the morphometry of mitochondria biogenesis, and proteomic was used complementary to unveil events underlying differences between two-dimensional/three-dimensional myoblasts differentiation. The prevalence of elongated mitochondria with an average area of 0.097 μm² was attributed to monolayer cells 7 days after the passage. The population of small mitochondria with a round shape and area of 0.049 μm² (p < 0.05) was observed in spheroid cells cultured under three-dimensional conditions. Cells in spheroids were quantitatively enriched in proteins of mitochondria biogenesis (DNM1L, IDH2, SSBP1), respiratory chain (ACO2, ATP5I, COX5A), extracellular proteins (COL12A1, COL6A1, COL6A2), and cytoskeleton (MYL6, MYL12B, MYH10). Most of the Rab-related transducers were inhibited in spheroid culture. The proteomic assay demonstrated delicate mechanisms of mitochondria autophagy and repopulation, cytoskeleton assembling, and biogenesis. Differences in the ultrastructure of mitochondria indicate active biogenesis under three-dimensional conditions.

In vitro three-dimensional cell cultures for bone sarcomas

Bone sarcomas are rare tumour entities that arise from the mesenchyme most of which are highly heterogeneous at the cellular, genetic and epigenetic levels. The three main types are osteosarcoma, Ewing sarcoma, and chondrosarcoma. These oncological entities are characterised by high morbidity and mortality and an absence of significant therapeutic improvement in the last four decades. In the field of oncology, in vitro cultures of cancer cells have been extensively used for drug screening unfortunately with limited success. Indeed, despite the massive knowledge acquired from conventional 2D culture methods, scientific community has been challenged by the loss of efficacy of drugs when moved to clinical trials. The recent explosion of new 3D culture methods is paving the way to more relevant in vitro models mimicking the in vivo tumour environment (e.g. bone structure) with biological responses close to the in vivo context. The present review gives a brief overview of the latest advances of the 3D culture methods used for studying primary bone sarcomas.

Molecular Mechanisms of Canine Osteosarcoma Metastasis

Osteosarcoma (OSA) represents the most common bone tumor in dogs. The malignancy is highly aggressive, and most of the dogs die due to metastasis, especially to the lungs. The metastatic process is complex and consists of several main steps. Assessment of the molecular mechanisms of metastasis requires in vitro and especially in vivo studies for a full evaluation of the process. The molecular and biological resemblance of canine OSA to its human counterpart enables the utilization of dogs as a spontaneous model of this disease in humans. The aim of the present review article is to summarize the knowledge of genes and proteins, including p63, signal transducer and activator of transcription 3 (STAT3), Snail2, ezrin, phosphorylated ezrin-radixin-moesin (p-ERM), hepatocyte growth factor-scatter factor (HGF-SF), epidermal growth factor receptor (EGFR), miR-9, and miR-34a, that are proven, by in vitro and/or in vivo studies, to be potentially involved in the metastatic cascade of canine OSA. The determination of molecular targets of metastatic disease may enhance the development of new therapeutic strategies.

Proteomic profiling and identification of significant markers from high-grade osteosarcoma after cryotherapy and irradiation

Biological reconstruction of allografts and recycled autografts have been widely implemented in high-grade osteogenic sarcoma. For treating tumor-bearing autografts, extracorporeal irradiation (ECIR) and liquid nitrogen (LN) freezing techniques are being used worldwide as a gold standard treatment procedure. Both the methods aim to eradicate the tumor cells from the local recurrence and restore the limb function. Therefore, it is essential and crucial to find, and compare the alterations at molecular and physiological levels of the treated and untreated OGS recycled autografts to obtain valuable clinical information for better clinical practice. Thus, we aimed to investigate the significantly expressed altered proteins from ECIR-and cryotherapy/freezing- treated OGS (n = 12) were compared to untreated OGS (n = 12) samples using LC-ESI-MS/MS analysis, and the selected proteins from this protein panel were verified using immunoblot analysis. From our comparative proteomic analysis identified a total of 131 differentially expressed proteins (DEPs) from OGS. Among these, 91 proteins were up-regulated (2.5 to 3.5-folds), and 40 proteins were down-regulated (0.2 to 0.5 folds) (p < 0.01 and 0.05). The functional enrichment analysis revealed that the identified DEPs have belonged to more than 10 different protein categories include cytoskeletal, extracellular matrix, immune, enzyme modulators, and cell signaling molecules. Among these, we have confirmed two potential candidates’ expressions levels such as Fibronectin and Protein S100 A4 using western blot analysis. Our proteomic study revealed that LN-freezing and ECIR treatments are effectively eradicating tumor cells, and reducing the higher expressions of DEPs at molecular levels which may help in restoring the limb functions of OGS autografts effectively. To the best of our knowledge, this is the first proteomic study that compared proteomic profiles among freezing, ECIR treated with untreated OGS in recycled autografts. Moreover, the verified proteins could be used as prognostic or diagnostic markers that reveal valuable scientific information which may open various therapeutic avenues in clinical practice to improve patient outcomes.

The Differences in the Proteome Profile of Cannabidiol-Treated Skin Fibroblasts following UVA or UVB Irradiation in 2D and 3D Cell Cultures

Cannabidiol (CBD), as the only phytocannabinoid that has no psychoactive effect, has both antioxidant and anti-inflammatory effects, and thus might be suggested as a cytoprotective compound against UV-induced metabolic changes in skin cells. Therefore, the aim of this study was to investigate the level of protective CBD activity by evaluating the proteomic profile of 2D and 3D cultured skin fibroblasts models following exposure to UVA and UVB radiation. The CBD cytoprotective effect against UV-induced damage in 2D and 3D cultured fibroblasts were different. The main alterations focus on the range of cell reaction and involved different proteins associated with various molecular functions. In the 2D cultured cells, following UV radiation, the major changes were associated with proteins involved in antioxidant response and inflammation, while, in the 3D cultured fibroblasts, CBD action against UV induced changes were mainly associated with the activation of signalling pathways. Therefore, the knowledge of the CBD action in a multilayer skin cells model allowed for the prediction of changes in cell-cell interactions and skin cell metabolism. Knowledge about the lower protective effect of CBD in 3D cultured fibroblasts should be taken into account during the design of UV light protection.

The comparison genomics analysis with glioblastoma multiforme (GBM) cells under 3D and 2D cell culture conditions

GBM, the most common and aggressive malignant primary brain tumors which needs new research approach to reveal the underline molecular mechanism of tumor progression. The 3D in vitro tumor model can be a simple and effective way to study tumor characteristics with ability to replicate of the tumor milieu. In the current study, we adopted the DNA microarray to analyze the gene expression of GBM tumor cells cultured under 2D cell culture flasks and 3D PLA porous scaffolds for 4,7 and 14 days. For 14 day old cultures, 8117 and 3060 genes expression were upregulated and downregulated respectively. Further KEGG pathway analysis revealed, the upregulated genes were mainly enriched/involved in PPAR and PI3K-Akt signaling pathways whereas the downregulated genes were mainly contributed in metabolism, ECM related and TGF-beta pathways. Thus, our approach of establishing 3D in vitro tumor model provides realistic results and proves itself a powerful tool for understanding the inner nature of GBM and can be considered as potential platform for drug screening.