Osteosarcoma Research Articles

Prognostic Significance of Microvessel Density and Hypoxic Markers in Canine Osteosarcoma: Insights into Angiogenesis and Tumor Aggressiveness

Canine osteosarcoma (OSA) is an aggressive and highly malignant tumor of bone with a poor prognosis and it mirrors the disease in humans. Angiogenesis, the formation of new blood vessels, is driven by hypoxia-induced factors such as HIF-1α and VEGF, both of which play a crucial role in tumor growth and metastasis. However, the role of angiogenesis in OSA remains a topic of ongoing debate. This study aimed to investigate the relationship between angiogenesis, measured by intratumoral microvessel density (MVD), hypoxic markers, and clinical outcomes in 28 dogs diagnosed with appendicular OSA. Clinicopathological data such as age, breed distribution, tumor localization, histopathological subtypes, and metastatic behavior were consistent with reported epidemiologic characteristics of canine OSA, though no significant correlation was found among these variables. The results indicated a significant association between higher MVD and high-grade OSA (p = 0.029), suggesting that increased tumor vascularization is linked to more aggressive tumor behavior. Additionally, elevated VEGF expression was strongly correlated with disease-free interval DFI), with a p-value of 0.045. Although HIF-1α positivity showed a trend towards poorer survival, the results did not reach statistical significance (p = 0.07). These findings highlight the potential role of VEGF as a valuable prognostic marker in canine OSA, which could have potentially important implications for therapeutic targeting and clinical management of the disease. This study advances the understanding of angiogenesis in canine OSA, while emphasizing the need for continued research into the complex mechanisms regulating the interplay between hypoxia, angiogenesis and tumor progression.

Advancing osteosarcoma 3D modeling in vitro for novel tumor microenvironment-targeted therapies development

Osteosarcoma (OS) represents one of the most common primary bone cancers affecting children and young adults. The available treatments have remained unimproved for the past decades, hampered by the poor knowledge of OS etiology/pathophysiology and the lack of innovative, predictive and biologically relevant in vitro models, that can recapitulate the 3D OS tumor microenvironment (TME). Here, we report the development and characterization of an innovative 3D model of OS, composed of OS tumor cells, immune cells (macrophages) and mesenchymal stem cells (MSCs), that formed a multicellular tissue spheroid (MCTS). This fully humanized 3D model was shown to accurately mimic the native histological features of OS, while innately leading to the polarization of macrophages towards an M2-like phenotype, highly aggressive and pro-tumor profile. Upon the exposure to immunomodulatory molecules, the MCTS were shown to be responsive by shifting macrophages polarization, and dramatically altering the TME secretome. In agreement, when treated with immunomodulatory/stimulatory nanoparticles (NPSs), we were able to revert the TME secretome towards an anti-inflammatory profile. This study establishes an advanced 3D OS model capable of shedding light on macrophages and MSCs contributions to disease progression, paving the way for the development of innovative therapeutic approaches targeting the OS TME, while providing a biologically relevant in vitro tool for the efficacy screening of novel OS therapeutic approaches.

Radiomics analysis in differentiating osteosarcoma and chondrosarcoma based on T2-weighted imaging and contrast-enhanced T1-weighted imaging

This study was performed to investigate the diagnostic value of radiomics models constructed by fat suppressed T2-weighted imaging (T2WI-FS) and contrast-enhanced T1-weighted imaging (CET1) based on magnetic resonance imaging (MRI) for differentiation of osteosarcoma (OS) and chondrosarcoma (CS). In this retrospective cohort study, we included all inpatients with pathologically confirmed OS or CS from Second Xiangya Hospital of Central South University (Hunan, China) as of October 2020. Demographic and imaging variables were extracted from electronic medical records and compared between OS and CS group. Totals of 530 radiomics features were extracted from CET1 and T2WI-FS sequences based on MRI. The least absolute shrinkage and selection operator (LASSO) method was used for screening and dimensionality reduction of the radiomics model. Multivariate logistic regression analysis was performed to construct the radiomics model, and receiver operating characteristic curve (ROC) was generated to evaluate the diagnostic accuracy of the radiomics model. The training cohort and validation cohort included 87 and 29 patients, respectively. 8 CET1 features and 15 T2WI-FS features were screened based on the radiomics features. In the training group, the area under the receiver-operator characteristic curve (AUC) value for CET1 and T2WI-FS sequences in the radiomics model was 0.894 (95% CI 0.817–0.970) and 0.970 (95% CI 0.940–0.999), respectively. In the validation group, the AUC value for CET1 and T2WI-FS sequences in the radiomics model was 0.821 (95% CI 0.642–1.000) and 0.899 (95% CI 0.785–1.000), respectively. In this study, we developed a radiomics model based on T2WI-FS and CET1 sequences to differentiate between OS and CS. This model exhibits good performance and can help clinicians make decisions and optimize the use of healthcare resources.

VCP enhances autophagy-related osteosarcoma progression by recruiting USP2 to inhibit ubiquitination and degradation of FASN

Osteosarcoma (OS) is a highly aggressive malignant tumor with a high rate of disability and mortality rates, and dysregulated autophagy is a crucial factor in cancer. However, the molecular mechanisms that regulate autophagy in OS remain unclear. This study aimed to explore key molecules that affect autophagy in OS and their regulatory mechanisms. We found that fatty acid synthase (FASN) was significantly increased in activated autophagy models of OS and promoted OS proliferation in an autophagy-dependent manner, as detected by LC3 double-labeled fluorescence confocal microscopy, western blotting, transmission electron microscopy (TEM), and cell functional experiments. Furthermore, co-immunoprecipitation combined with mass spectrometry (Co-IP/MS), ubiquitination modification, molecular docking, and protein truncation methods were used to identify FASN-interacting proteins and analyze their effects on OS. Valosin-containing protein (VCP) enhanced the FASN stability by recruiting ubiquitin specific peptidase-2 (USP2) to remove the K48-linked ubiquitin chains from FASN; domain 2 of VCP and the amino acid sequence () of USP2 were critical for their interactions. Gain- and loss-of-function experiments showed that the inhibition of FASN or USP2 attenuated the stimulatory effect of VCP overexpression on autophagy and the malignant phenotypes of OS cells in vitro and in vivo. Notably, micro-CT indicated that VCP induced severe bone destruction in nude mice, which was abrogated by FASN or USP2 downregulation. In summary, VCP recruits USP2 to stabilize FASN by deubiquitylation, thereby activating autophagy and promoting OS progression. The identification of the VCP/USP2/FASN axis, which mediates autophagy regulation, provides important insights into the underlying mechanisms of OS and offers potential diagnostic and therapeutic strategies for patients with OS.

Inhibition of mitochondrial OMA1 ameliorates osteosarcoma tumorigenesis

OMA1 is an ATP-independent zinc metalloprotease essential for maintaining mitochondrial homeostasis and plays a vital role in tumorigenesis. Depending on the type of cancer, a decrease in OMA1 expression has been linked to a varying prognosis for patients. The role of OMA1 in human osteosarcoma (OS), one of the most prevalent malignant bone tumors, remains elusive. Here, we observed elevated OMA1 expression in OS tumor tissues from four patients with advanced OS. Knockout of OMA1 in OS cells significantly reduces OS tumor weight and size, and lung metastatic nodules in BALB/c nude mice. Immunohistochemistry analysis showed a significant decrease in Ki67 and an increase in Cleaved-caspase 3 in OMA1 knockout tumor samples. Mechanistically, we found that OMA1 deficiency increases the levels of PINK1 and Parkin and consequently induces excessive mitophagy, leading to increased apoptosis and reduced cell proliferation and invasion in OS cells. Specifically, OMA1 deficiency reduces the amount of cytosolic p53 and p53-associated cytosolic Parkin but increases mitochondrial p53, which may lead to enhanced apoptosis. Regarding the effect on cell proliferation and invasion, loss of OMA1 reduces mitochondrial ROS levels and increases cytosolic glycogen synthase kinase 3β (GSK3β) levels, thereby increasing interaction between GSK3β and β-catenin and then reducing cytosolic and nuclear β-catenin. This contributes to reduced cell proliferation and migration in OMA1-deficient cells. Moreover, we found that ciclopirox (CPX), an antifungal drug, induces OMA1 self-cleavage and L-OMA1 degradation in cultured OS cells. CPX also reduces tumor development of control OS cells but not OMA1-deficient OS cells in mice. These findings strongly support the important role of OMA1 in OS tumorigenesis and suggest that OMA1 may be a valuable prognostic marker and a promising therapeutic target for OS.

Decoding core genes and intercellular communication in osteosarcoma: bioinformatic investigation and immune cell profiling for diagnostic and therapeutic insights

The study focusing on developing an artificial neural network (ANN) model in accordance with genetic characteristics of osteosarcoma (OS) to accurately speculate OS cases. In the present study, we identified 467 DEGs through differentially acting gene investigation and that 345 exist suppressed and 122 exist stimulated. The resultant of GO enrichment analysis displayed the functions mainly included T cell activation, secretory granule lumen, antioxidant property etc. The pathways identified in the differentially acting genes (DAGs) were greatly interacted with Phagosome, Staphylococcus aureus infection, Human T − cell leukemia virus 1 infection, etc. Next, we found out top ten hub DEGs (HDEGs) by PPI network analysis. In addition, through the validation of ANN itself and Test set samples, it was proved that the prediction performance of our constructed ANN model is accurate and reliable. Finally, the penetration of immune cells and its interaction with target CDEGs were examined, and variations in penetration of 22 types of immune cells amongst different classes were found, additionally correlation amongst immune cells and between immune cells and target CDEGs. Furthermore, we analyzed the expression of the top two CDEGs (YES1 and MFNG) in OS tissues and normal tissues, also the interrelationship among the activity of YES1 and MFNG in OS tissues and clinicopathological properties of OS cases. Furthermore, the correlation analysis between the top two CDEGs and immune infiltrating cells was performed in OS tissues. Our research results revealed that CDEGs-based ANN model is effective at predicting OS patients, which facilitates early diagnosis and treatment of OS.

M2 macrophage exosome-derived Apoc1 promotes ferroptosis resistance in osteosarcoma by inhibiting ACSF2 deubiquitination.

Osteosarcoma (OS) is the most common primary malignant tumor of bone. The aim of this study was to investigate the regulatory mechanisms of M2 macrophage exosomes (M2-Exos) in ferroptosis in OS. A mouse model was established to investigate the in vivo role of M2-Exos. We investigated their effects on ferroptosis in OS using erastin, a ferroptosis activator, and deferoxamine mesylate, an iron chelator. In vitro, we investigated whether the Apoc1/Acyl-CoA Synthetase Family Member 2 (ACSF2) axis mediates these effects, using shApoc1 and shACSF2. The mechanisms whereby Apoc1 regulates ACSF2 were examined using cyclohexanone, a protein synthesis inhibitor, and MG132, a proteasomal inhibitor. M2-Exos reversed the inhibitory effects of erastin on OS cells, thus enhancing their viability, migration, invasion, proliferation, and reducing ferroptosis. Apoc1 was highly expressed in M2-Exos, and interfering with this expression reversed the effects of M2-Exos on OS cells. ACSF2 mediated the effects of M2-Exos-derived Apoc1. Apoc1 interacted with ACSF2, which, in turn, interacted with USP40. Apoc1 overexpression increased ACSF2 ubiquitination, promoting its degradation, whereas USP40 overexpression inhibited ACSF2 ubiquitination and promoted its expression. Apoc1 overexpression inhibited ACSF2 binding to USP40. M2-Exos-derived Apoc1 promoted ferroptosis resistance by inhibiting USP40 binding to ACSF2 and promoting ACSF2 ubiquitination and degradation, thus enhancing OS development.

The Landscape of microRNAs in Bone Tumor: A Comprehensive Review in Recent Studies.

Cancer, the second greatest cause of mortality worldwide, frequently causes bone me-tastases in patients with advanced-stage carcinomas such as prostate, breast, and lung cancer. The existence of these metastases contributes to the occurrence of skeletal-related events (SREs), which are defined by excessive pain, pathological fractures, hypercalcemia, and spinal cord com-pression. These injurious incidents leave uncomfortably large holes in each of the cancer patient's life quality. Primary bone cancers, including osteosarcoma (OS), chondrosarcoma (CS), and Ewing's sarcoma (ES), have unclear origins. MicroRNA (miRNA) expression patterns have been changed in primary bone cancers such as OS, CS, and ES, indicating a role in tumor development, invasion, metastasis, and treatment response. These miRNAs are persistent in circulation and ex-hibit distinct patterns in many forms of bone tumors, making them potential biomarkers for early detection and treatment of such diseases. Given their crucial regulatory functions in various bio-logical processes and conditions, including cancer, this study aims to look at miRNAs' activities and possible contributions to bone malignancies, focusing on OS, CS, and ES. In conclusion, miRNAs are valuable tools for diagnosing, monitoring, and predicting OS, CS, and ES outcomes. Further research is required to fully comprehend the intricate involvement of miRNAs in these bone cancers and to develop effective miRNA-based treatments.

Trifluoperazine exerts anti-osteosarcoma effect by inducing mitochondria-dependent apoptosis via AKT/TXNIP signaling pathway

The survival rates for patients with osteosarcoma (OS) have stagnated over the past few decades. It is essential to find new therapies and drugs. A licensed antipsychotic medication called trifluoperazine (TFP) significantly reduces the growth of several cancers. However, the exact molecular pathways of TFP in OS remain to be discovered. Our research revealed that TFP greatly reduced OS cell migration and growth and caused the arrest of G0/G1 cell cycle. Combined with RNA-Seq data and further research, we confirmed that TFP promoted reactive oxygen species (ROS) production by elevating thioredoxin binding protein (TXNIP) expression to induce mitochondria-dependent apoptosis. Interestingly, we first demonstrated that AKT was an upstream regulatory target of TXNIP in OS cells. Dephosphorylation of AKT led to an increase in TXNIP expression, further elucidating the anticancer mechanism of TFP. In vivo, TFP inhibited subcutaneous OS cell proliferation and induced OS cell apoptosis without noticeable side effects. In conclusion, our findings imply that TFP is a potential treatment for OS.

AI based diagnostics product design for osteosarcoma cells microscopy imaging of bone cancer patients using CA-MobileNet V3

ObjectiveThe incidence of osteosarcoma (OS) is low, but primary malignant bone tumors rank third among the causes of death in cancer patients under the age of 20. Currently, analysis of cellular structure and tumor morphology through microscopic images remains one of the main diagnostic methods for osteosarcoma. However, this completely manual approach is tedious, time-consuming, and difficult to diagnose accurately due to the similarities in certain characteristics of malignant and benign tumors. MethodsLeveraging the potential of artificial intelligence (AI) in assessing and classifying images, this study explored a modified CA-MobileNet V3 model that was embedded into innovative microscope products to enhance the microscope’s feature extraction capabilities and help reduce misclassification during diagnosis. ResultsThe intelligent recognition model method introduced in this paper has significant advantages in retrieval and classification of osteosarcoma cells and other cell types. Compared with models such as ShuffleNet V2, EfficientNet V2, Mobilenet V3 (without transfer learning), TL-MobileNet V3 (with transfer learning), etc., the model size is only 5.33 MB, is a lightweight model, and the accuracy of the improved model reached 98.69 %. In addition, the artificial intelligence microscope (AIM) with integrated design based on this model can also help improve diagnostic efficiency. ConclusionThe innovative method of the CA-MobileNet V3 automatic classification model based on deep learning provides an efficient and reliable solution for the pathological diagnosis of osteosarcoma. This study contributes to medical image analysis and provides doctors with an accurate and valuable tool for microscopic diagnosis. It also promotes the advancement of artificial intelligence in medical imaging technology.

Tellurium-Doped Bioactive Glass Induces Ferroptosis in Osteosarcoma Cells Regardless of FSP1

Human osteosarcoma (OS) is a rare tumor predominantly affecting long bones and characterized by a poor prognosis. Currently, the first line of intervention consists of the surgical resection of primary tumors combined with radiotherapy and chemotherapy, with a profound impact on the patient’s life. Since the surgical removal of OS frequently results in a large resection of bones, the use of biomaterials to sustain the stability of the remaining tissue and to stimulate bone regeneration is challenging. Moreover, residual neoplastic cells might be responsible for tumor recurrence. Here, we explored the potential of tellurium-ion-doped bioactive glass as a novel therapeutic intervention to both eradicate residual malignant cells and promote bone regeneration. Bioactive glass (BAG) has been extensively studied and employed in the field of regenerative medicine due to its osseointegration properties and ability to improve bone tissue regeneration. We found that the incorporation of tellurium (Te) in BAG selectively kills OS cells through ferroptosis while preserving the viability of hBMSCs and stimulating their osteodifferentiation. However, the mechanism of Te toxicity is still unclear: (i) Te-BAG generates lipid-ROS through LOXs activity but not iron overload; (ii) Te-dependent ferroptosis is mediated by GPX4 down-regulation; and (iii) the anti-ferroptotic activity of FSP1 is abrogated, whose expression confers the resistance of OS to the canonical induction of ferroptosis. Overall, our data show that Te-doped bioglass could represent an interesting biomaterial with both pro-ferroptotic activity towards residual cancer cells and pro-osteoregenerative activity.

Genetic changes clinically relevant in canine osteosarcoma

Osteosarcoma (OSA) is a malignant tumour of osteoblasts, forming neoplastic bone and/or osteoid. The cancer is most prevalent in children and canines, although occurring 10 times more frequently in the latter (Fenger et al., 2014). Up to 85% of malignant bone cancers are diagnosed as OSA, characterised by aggressive metastasis and rapid haematogenous dissemination, particularly to the lungs (Nelson and Couto, 2019, Thompson and Dittmer, 2020). These most commonly occur in dogs aged between 7-10 years (Selvarajah et al., 2009). The nature of canine osteosarcoma (CnOSA) gravitates to the appendicular skeleton, with 95% prevalence in dogs over 40kg, and 40% prevalence in dogs under 15kg (Nelson and Couto, 2019). Regardless of the high prevalence of CnOSA, there has been little progression in improving survival rates in the last 50 years (Zapata et al., 2019). This may be a consequence of the spontaneity of the cancer in canines (Davis and Ostrander, 2014). However, recent combined utilisation of genomic/transcriptomic technologies has been of benefit to investigating genetic loci as causes and/or protectors against CnOSA (Davis and Ostrander, 2014). As a result, somatic mutations in the TP53, MYC, CDKN2A/B, PTEN, RUNX2, and DLG2 genes in humans and dogs with osteosarcoma– and KIT and MDM2 in OSA dogs alone have been identified (Zapata et al., 2019). These findings are not only of prognostic importance to the several dog breeds with genetic predispositions to CnOSA (Simpson et al., 2017), but for humans too. This is not purely for better diagnosis of at-risk patients, but for earlier management, and a foundation for novel approaches to treatment targets for OS. Therefore, this literature review aims to identify the genetic changes clinically relevant in dogs with osteosarcoma.

The Contribution of the Novel CLTC-VMP1 Fusion Gene to Autophagy Regulation and Energy Metabolism in Cisplatin-Resistant Osteosarcoma.

Osteosarcoma (OS) is a highly malignant tumor, and chemotherapy resistance is a major challenge in the treatment of this disease. This study aims to explore the role of the CLTC-VMP1 gene fusion in the mechanism of chemotherapy resistance in OS and investigate its molecular mechanisms in mediating energy metabolism reprogramming by regulating autophagy and apoptosis balance. Using single-cell transcriptome analysis, the heterogeneity of OS cells and their correlation with resistance to platinum drugs were revealed. Cisplatin-resistant cell lines were established in human OS cell lines for subsequent experiments. Based on transcriptomic analysis, the importance of VMP1 in chemotherapy resistance was confirmed. Lentiviral vectors overexpressing or interfering with VMP1 were used, and it was observed that inhibiting VMP1 could reverse cisplatin resistance, promote cell apoptosis, and inhibit autophagy, as well as mitochondrial respiration and glycolysis. Furthermore, the presence of CLTC-VMP1 gene fusion was validated, and its ability to regulate autophagy and apoptosis balance, promote mitochondrial respiration, and glycolysis was demonstrated. Mouse model experiments further confirmed the promoting effect of CLTC-VMP1 on tumor growth and chemotherapy resistance. In summary, the CLTC-VMP1 gene fusion mediates energy metabolism reprogramming by regulating autophagy and apoptosis balance, which promotes chemotherapy resistance in OS.

Development and validation of a novel endoplasmic reticulum stress-related lncRNAs signature in osteosarcoma

Osteosarcoma (OS) is a cancerous tumor, and its development is greatly influenced by long non-coding RNA (lncRNA). Endoplasmic reticulum stress (ERS) is an essential biological defense process in cells and contributes to the progression of tumors. However, the exact mechanisms remain elusive. This study aims to develop a signature of lncRNAs associated with ERS in OS. This signature will guide the prognosis prediction and the determination of appropriate treatment strategies. The UCSC Xena database collected transcriptional and clinical data of OS and muscle, after identifying ERS differentially expressed genes, we utilized correlation analysis to determine the endoplasmic reticulum stress lncRNAs (ERLs). The Least Absolute Shrinkage and Selection Operator (LASSO) and Cox regression analysis were utilized to develop an ERLs signature. To clarify the fundamental mechanisms controlling gene expression in low and high-risk groups, Gene Set Variation Analysis (GSVA) were conducted. In addition, the distinction between the two groups regarding drug sensitivity and immune-related activity was investigated to determine the immunotherapy effects. Utilizing RT-qPCR, the expression of model lncRNAs in OS cell lines was ascertained. The functional analysis of LINC02298 was carried out through in vitro experiments and pan-cancer analysis. This study successfully constructed an ERLs prognostic signature for OS, which comprised 5 lncRNAs (AC023157.3, AL031673.1, LINC02298, LINC02328, SNHG26). The risk signature predicted overall survival in patients with OS and was confirmed by assessing the validation and whole cohorts. Further, it was discovered that individuals classified as high-risk displayed suppressed immune activation, decreased infiltration of immune cells, and decreased responsiveness to immunotherapy. The RT-qPCR showed that the constructed risk prognosis model is reliable. Experimental validation has demonstrated that LINC02298 can promote OS cells’ invasion, migration, and proliferation. In addition, LINC02298 exhibited significant differential expression in many types of cancer. Moreover, LINC02298 is an important biomarker in a variety of tumors. This study established a novel ERLs signature, which successfully predicted the prognosis of OS. The function of LINC02298 in OS was elucidated via in vitro experiments. Therefore, it offers new opportunities for predicting the clinical prognosis of OS and establishes the basis for targeted therapy in OS.

Integrated immunogenomic analyses of single-cell and bulk profiling construct a T cell-related signature for predicting prognosis and treatment response in osteosarcoma

PurposesT cells play a crucial role as regulators of anti-tumor activity within the tumor microenvironment (TME) and are closely associated with the progression of osteosarcoma (OS). Nevertheless, the specific role of T cell-related genes (TCRGs) in the pathogenesis of OS remains unclear.MethodsFirst, we processed single-cell RNA sequencing (scRNA-seq) data of OS from the public databases and performed cell annotation. We identified highly variable genes in each cell type using the "FindAllMarkers" function, explored the distribution of different clusters, and investigated inter-cellular communication patterns via the "CellChat" framework. Then, we used multivariate Cox analysis to construct a TCRG and developed a nomogram to predict survival probabilities for OS patients. Finally, we validated the aforementioned results using various cell lines and investigated the immune cell infiltration, expression of immune checkpoints, chemotherapy sensitivity, and the efficacy of targeted therapies across different risk groups.ResultsFrom the scRNA-seq data, we identified 3,000 highly variable genes, presented the top 10 genes, and validated the expression of core genes across different cell lines.Moreover, our analysis delved into interactions between T cells and other cell types. Our analyses constructed a predictive T cell-related signature (TCRS) that incorporated these prognostic TCRGs, showing a clear prognostic separation between the high-risk and low-risk OS patient groups in multiple cohorts. Survival analysis indicated better outcomes for patients classified in the high-risk group. The low-risk group exhibited elevated levels of CD4 memory resting T cells, contrasting with the higher levels of macrophage M0 observed in the high-risk group via the CIBERSORT algorithm. Furthermore, we observed that the low-risk group exhibitedAQ1 significant up-regulation of immune checkpoint genes (ICGs) and lower Tumour Immune Dysfunction and Exclusion (TIDE) scores, suggesting that they may be suitable for immunotherapy. Conversely, the high-risk group appeared more responsive to chemotherapy and targeted therapies, according to our drug sensitivity analysis.ConclusionIn conclusion, our study identified TCRGs, constructed and validated a TCRS for OS, and assessed immune response and drug sensitivity in different risk groups of OS patients. These findings provide novel insights into personalized treatment strategies for OS, potentially guiding more effective therapeutic interventions.

Curcumin and Methotrexate: A Promising Combination for Osteosarcoma Treatment via Hedgehog Pathway Inhibition

Osteosarcoma (OS) is the most severe bone tumor in children. A chemotherapy regimen includes a combination of high-dose Methotrexate (MTX), doxorubicin, and cisplatin. These drugs cause acute and chronic side effects, such as infections, thrombocytopenia, neutropenia, DNA damage, and inflammation. Therefore, to identify new therapeutic strategies, effective and with a safety profile, is necessary. The Hedgehog (Hh) signaling pathway involved in tumorigenesis is active in OS. Hh components Patched receptor 1 (PTCH1), Smoothened (SMO), and glioma-associated oncogene homolog transcription factors (GLI1 and GLI2) are overexpressed in OS cell lines and patient samples. Curcumin (CUR)—with antioxidant and anti-cancer properties—downregulates Hh components in cancer, inhibiting progression. This study investigates CUR effects on the MG-63 OS cell line, alone and combined with MTX, to propose a novel therapeutic approach. Our study suggests CUR as a novel therapeutic agent in OS, particularly when combined with MTX. Targeting the Hh signaling pathway, CUR and MTX showed significant pro-apoptotic effects, increasing the BAX/Bcl-2 ratio and total apoptotic cell percentage. They reduced the expression of Hh pathway components (PTCH1, SMO, GLI1, and GLI2), inhibiting OS cell proliferation, survival, and invasion. CUR and MTX combined determined a β-Catenin decrease and a trend toward reducing NF-kB and matrix metalloproteinases (MMP-2 and MMP-9). Our findings suggest CUR as a support to OS treatment, improving outcomes and reducing the adverse effects of current therapies.

Histone deacetylase upregulation of neuropilin-1 in osteosarcoma is essential for pulmonary metastasis

The lungs represent the most common site of metastasis for osteosarcoma (OS). Despite our advances in developing targeted therapies for treating solid malignancies, broad acting chemotherapies remain the first line treatment for OS. In assaying the efficacy of approved therapeutics for non-OS malignancies, we previously identified the histone deacetylase 1 and 2 (HDAC1 and 2) inhibitor, romidepsin, as effective for the treatment of established lung metastatic OS. Yet, romidepsin has noted toxicities in humans and so here we aimed to define the primary mechanisms through which HDAC1/2 mediate OS progression to identify more selective druggable targets/pathways. Microarray and proteomics analyses of romidepsin treated OS cells revealed a significant suppression of neuropilin-1 (NRP1), a known regulator of cancer cell migration and invasion. Silencing of NRP1 significantly reduced OS proliferation, migration, invasion and adhesion in vitro. More strikingly, in vivo, reduced NRP1 expression significantly mitigated the lung metastatic potential of OS in two independent models (K7M2 and SAOS-LM7). Mechanistically, our data point to NRP1 mediating this effect via the down regulation of migration machinery, namely SRC, FAK and ROCK1 expression/activity, that is in part, related to NRP1 interaction with integrin beta 1 (ITGB1). In summary, our data indicate that romidepsin down regulation of NRP1 significantly mitigates the ability of OS cells to seed the lung and establish metastases, and that targeting NRP1 or its effectors with selective inhibitors may be a viable means with which to prevent this deadly aspect of the disease.

MicroRNA signatures in osteosarcoma: diagnostic insights and therapeutic prospects.

Osteosarcoma (OSa) is the most prevalent primary malignant bone tumor in children and adolescents, characterized by complex genetic and epigenetic alterations. Traditional treatments face significant challenges due to high rates of drug resistance and lack of targeted therapies. Recent advances in microRNA (miRNA) research have opened new avenues for understanding and treating osteosarcoma. This review explores the many critical functions of miRNAs in osteosarcoma, particularly their potential for clinical use. The review highlights two key areas where miRNAs could be beneficial. Firstly, miRNAs can act as biomarkers for diagnosing osteosarcoma and predicting patient prognosis. Secondly, specific miRNAs can regulate cellular processes like proliferation, cell death, migration, and even resistance to chemotherapy drugs in osteosarcoma. This ability to target multiple pathways within cancer cells makes miRNA-based therapies highly promising. Additionally, though the interaction between miRNAs and circular RNAs (circRNAs) falls outside the scope of the paper, it has also been discussed briefly. While miRNA-based therapies offer exciting possibilities for targeting multiple pathways in osteosarcoma, challenges remain. Efficient delivery, potential off-target effects, tumor complexity, and rigorous testing are hurdles to overcome before these therapies can reach patients. Despite these challenges, continued research and collaboration among scientists, clinicians, and regulatory bodies hold the promise of overcoming them. This collaborative effort can pave the way for the development of safe and effective miRNA-based treatments for osteosarcoma.

Aucubin Induces Apoptotic Cell Death Through Caspase-dependent Pathways in Human Osteosarcoma MG-63 Cells

Background Osteosarcomas (OSs) are predominantly generated by mesenchymal cells, which commonly develop in the distal and upper regions of the bones. OS has high mortality rates and treatment failures, mostly due to the presence of lung metastases. Purpose The present work aimed to scrutinize the anticancer potentials of aucubin against OS human osteosarcoma (MG-63) cells. Methods The proliferation of the control and aucubin-treated MG-63 cells was studied by an XTT assay. Various fluorescent staining assays were done to assess the endogenous reactive oxygen species (ROS) accumulation and apoptosis in the aucubin-treated MG-63 cells. The caspase-3, -8, and -9 activities were investigated using the assay kits. Results The XTT assay results confirmed that the aucubin treatment considerably reduced the MG-63 cells. The findings of the various fluorescent staining assays evidenced that the aucubin treatment remarkably promoted endogenous ROS accumulation and apoptosis in the OS cells. The caspase activities were also improved in the OS cells after the aucubin treatment. Conclusion The results of this work show that aucubin treatments inhibit cell proliferation and trigger apoptosis in MG-63 cells, suggesting its potential as a promising anticancer agent. These findings will facilitate the future development of aucubin as a talented anticancer agent to treat OS.

Gene expression profile comparison of primary and pulmonary metastatic lesions in a dog with appendicular osteosarcoma and hypertrophic osteopathy

Hypertrophic osteopathy (HO) is a paraneoplastic syndrome, and the most notable cause in dogs is pulmonary metastatic osteosarcoma (OSA). Although many molecular factors in canine OSA have been shown in metastasis, little is known about the gene expression profile of HO secondary to metastatic OSA. Therefore, the purpose of this study was to compare the gene expression profiles between primary and metastatic OSA lesions from the same dog and to look for gene expression changes that can elucidate the molecular mechanism of metastases and HO. Tumoral samples were obtained from a 2-year-old, intact male, Labrador retriever. At the first visit, the patient presented with an appendicular OSA as the primary lesion. About 10 months later, the dog developed HO due to a single pulmonary metastasis. Using these primary and metastatic samples from the same dog, as well as normal canine osteoblasts, we investigated the gene expression profiling using the NanoString nCounter® Canine IO panel. A total of 180 differentially expressed genes were identified between malignant OSA cells and non-malignant canine osteoblasts. Furthermore, 5 genes (CCL17, VEGFC, C3, C4BPA, and FOS) were differentially expressed in comparison between primary and metastatic OSA samples. CCL17 and VEGFC were upregulated in the primary lesion compared to the metastatic lesion, while C3, C4BPA, and FOS were downregulated in the primary lesion relative to the metastatic lesion. Given that the metastatic lesion was relevant to the development of HO, the different gene expression profiles may be relevant to understanding the pathophysiology of HO.