Progress in the chemotherapeutic treatment of osteosarcoma

Curcumin-loaded scaffolds in bone regeneration

In recent years, there has been a notable surge in the development of engineered bone scaffolds intended for the repair of bone defects. While autografts and allografts have traditionally served as the primary methods in bone tissue engineering, their inherent limitations have spurred the exploration of novel avenues in biomedical implant development. The emergence of bone scaffolds not only facilitates bone reconstruction but also offers a platform for the targeted delivery of therapeutic agents. There exists a pervasive interest in leveraging various drugs, proteins, growth factors, and biomolecules with osteogenic properties to augment bone formation, as the enduring side effects associated with current clinical modalities necessitate the pursuit of safer alternatives. Curcumin, the principal bioactive compound found in turmeric, has demonstrated notable efficacy in regulating the proliferation and differentiation of bone cells while promoting bone formation. Nevertheless, its utility is hindered by restricted water solubility and poor bioavailability. Strategies aimed at enhancing the solubility, stability, and bioavailability of curcumin, including formulation techniques such as liposomes and nanoparticles or its complexation with metals, have been explored. This investigation is dedicated to exploring the impact of curcumin on the proliferation, differentiation, and migration of osteocytes, osteoblasts, and osteoclasts.

3D Models of Sarcomas: The Next-generation Tool for Personalized Medicine

Sarcoma is a complex and heterogeneous cancer that has been difficult to study in vitro. While two-dimensional (2D) cell cultures and mouse models have been the dominant research tools, three-dimensional (3D) culture systems such as organoids have emerged as promising alternatives. In this review, we discuss recent developments in sarcoma organoid culture, with a focus on their potential as tools for drug screening and biobanking. We also highlight the ways in which sarcoma organoids have been used to investigate the mechanisms of gene regulation, drug resistance, metastasis, and immune interactions. Sarcoma organoids have shown to retain characteristics of in vivo biology within an in vitro system, making them a more representative model for sarcoma research. Our review suggests that sarcoma organoids offer a potential path forward for translational research in this field and may provide a platform for developing personalized therapies for sarcoma patients.

Immunogenic cell death related mRNAs associated signature to predict immunotherapeutic response in osteosarcoma

Background

Immunogenic cell death (ICD) is related to cancer prognosis, which has a synergic effect in combination with chemotherapy or immunotherapy. Yet, the relationship between ICD and osteosarcoma remained unclear.

Materials and methods

Three osteosarcoma datasets including therapeutically applicable research to generate effective treatments (TARGET), GSE126209 and GSE21257 datasets were included. A protein-protein interaction network was constructed based on ICD-related genes. We performed unsupervised consensus clustering to classify molecular subtypes (clusters). Survival analysis, Estimation of stromal and immune cells in malignant tumour tissues using expression data (ESTIMATE), Cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT), and differential analysis were employed to characterize the molecular differences between different clusters. Univariate Cox regression analysis was conducted to confirm prognostic genes. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to demonstrate the aberrant expression of ICD-correlated signature genes in osteosarcoma. A series of cellular experiments, including cell counting kit-8 (CCK-8), transwell, and flow cytometry, were used to demonstrate the regulatory role of key genes in the ICD model on the malignant phenotype of osteosarcoma.

Results

Three clusters (cluster1, 2, 3) were constructed and they showed distinct overall survival and immune infiltration. ICD-related genes were highly expressed in cluster1. Moreover, Cluster1 had the best prognosis, high immune score and high expression of human leukocyte antigen (HLA)-related genes. TLR4, LY96, IFNGR1, CD4, and CASP1 were identified as prognostic genes for establishing an ICD-related risk signature. According to the risk signature, two risk groups (high and low risks) showing differential prognosis and response to immunotherapy. The low risks group had a better prognosis but was not sensitive to immunotherapy. Molecular assays verified that prognostic genes were abnormally under-expressed in osteosarcoma. Cellular assays demonstrated that LY96, the most significantly down-regulated gene in osteosarcoma, inhibited the migration, invasion, and proliferation phenotypes of osteosarcoma cells and prolonged the cell cycle. Analysis of oxidative stress related pathway enrichment in tumor microenvironment was conducted by single-sample gene set enrichment analysis (ssGSEA).

Conclusions

This study demonstrated the prognostic significance of ICD-correlated genes in osteosarcoma patients. The five-gene risk signature facilitate prognostic evaluation and prediction of osteosarcoma patients' response to immunotherapy. The risk signature also offered a possibility for the exploit of novel ICD-related treatment.

Microvessel Density (MVD) in Patients with Osteosarcoma: A Systematic Review and Meta-Analysis

A meta-analysis was designed and conducted to estimate the effect of tumoral microvessel density (MVD) on the survival of patients with osteosarcoma. There was no difference between high and low MVD regarding the overall (OS) and disease-free (DFS) survival. Low MVD tumors displayed a lower DFS at the third year of follow-up. Although primary metastases did not affect the mean MVD measurements, tumors with a good chemotherapy response had a higher MVD value. Although no significant differences between tumoral MVD, OS and DFS were found, good adjuvant therapy responders had a significant higher vascularization pattern.

Necrotizing apoptosis-related genes prognosis and treatment effect analysis of osteosarcoma in children

BACKGROUND

Immune cell homeostasis plays a crucial role in cancer research and therapeutic response. While chemotherapy and immunotherapy hold promise in treating osteosarcoma (OS), identifying patients who are likely to respond would significantly improve clinical practices. Necroptosis, a fundamental mechanism mediating chemotherapy and immunotherapy efficacy, offers valuable insights. In this context, subtypes based on necroptosis-related genes have been established to predict the response of OS patients to immunotherapy and chemotherapy.

METHODS

We conducted a high-throughput screening test to identify necroptosis-associated genes that regulate the development of osteosarcoma. Subsequently, the ConsensusClusterPlus package was employed to classify OS patients into subtypes, enabling comparisons of prognosis and clinical information between these subtypes. Patients from the TARGET-OS and GSE21257 datasets were stratified into high-risk and low-risk groups, and their prognoses were compared. Additionally, we assessed the accuracy of the Risk Scoring Model in predicting prognosis, identified independent prognostic factors and explored potential chemotherapeutic agents and immunotherapy drugs.

RESULTS

Through the intersection of expression profiles from the TARGET-OS and GSE21257 datasets, we have identified a total of 92 genes associated with necroptosis. Based on differences in the expression of these genes, patients were divided into three subtypes, and we investigated the differences in tumor-infiltrating immune cells, immune-related pathways, and prognosis among these subtypes. Our nomogram effectively differentiated subtypes with distinct responses to chemotherapy and immunotherapy. The established signature demonstrated superior prediction ability compared with single clinical indicators.

CONCLUSIONS

This pioneering study unveils the prognostic role of necroptosis-related genes in OS patients, providing a promising alternative for prognostic prediction in clinical disease management. Moreover, our findings highlight the significance of immune cell homeostasis in cancer research and therapeutic response, underscoring its relevance in advancing current treatment strategies.

The effects of evidence-based nursing interventions on pressure ulcers in patients with stroke: a meta-analysis

This meta-analysis evaluated the role of evidence-based nursing interventions in preventing pressure ulcers in patients with stroke. Computer systems were used to retrieve randomised controlled trials (RCTs) on evidence-based nursing interventions for patients with stroke and comorbid pressure ulcers from PubMed, EMBASE, Scopus, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature Database and Wanfang Data from database inception until April 2023. Two researchers independently screened the literature, extracted the data and evaluated the quality of the included studies according to the inclusion and exclusion criteria. RevMan 5.4 software was used for the meta-analysis. A total of 23 articles with results on 2035 patients were included, with 1015 patients in the evidence-based nursing group and 1020 patients in the routine nursing group. The meta-analysis results showed that evidence-based nursing interventions significantly reduced the incidence of pressure ulcers in patients with stroke (5.22% vs. 22.84%, odds ratio [OR]: 0.18, 95% confidence interval [CI]: 0.13-0.24, p < 0.001), delayed the onset of pressure ulcers (standardised mean difference [SMD]: 3.41, 95% CI: 1.40-5.42, p < 0.001) and improved patient quality of life (SMD: 2.95, 95% CI: 2.35-3.56, p < 0.001). Evidence-based nursing interventions are effective at preventing pressure ulcers in patients with stroke, delaying the onset of pressure ulcers and improving their quality of life. Evidence-based nursing should be promoted for patients with stroke. However, owing to differences in sample size between studies and the methodological inadequacies of some studies, these results should be verified by large, high-quality RCTs.

Biodistributions and Imaging of Poly(ethylene glycol)-Conjugated Silicon Quantum Dot Nanoparticles in Osteosarcoma Models via Intravenous and Intratumoral Injections

Osteosarcoma is a malignant tumor with relatively high mortality rates in children and adolescents. While nanoparticles have been widely used in assisting the diagnosis and treatment of cancers, the biodistributions of nanoparticles in osteosarcoma models have not been well studied. Herein, we synthesize biocompatible and highly photoluminescent silicon quantum dot nanoparticles (SiQDNPs) and investigate their biodistributions in osteosarcoma mouse models after intravenous and intratumoral injections by fluorescence imaging. The bovine serum albumin (BSA)-coated and poly(ethylene glycol) (PEG)-conjugated SiQDNPs, when dispersed in phosphate-buffered saline (PBS), can emit red photoluminescence with the photoluminescence quantum yield more than 30% and have very low in vitro and in vivo toxicity. The biodistributions after intravenous injections reveal that the SiQDNPs are mainly metabolized through the livers in mice, while only slight accumulation in the osteosarcoma tumor is observed. Furthermore, the PEG conjugation can effectively extend the circulation time. Finally, a mixture of SiQDNPs and indocyanine green (ICG), which complement each other in the spectral range and diffusion length, is directly injected into the tumor for imaging. After the injection, the SiQDNPs with relatively large particle sizes stay around the injection site, while the ICG molecules diffuse over a broad range, especially in the muscular tissue. By taking advantage of this property, the difference between the osteosarcoma tumor and normal muscular tissue is demonstrated.

Anticancer Potential of Farnesol Against Human Osteosarcoma Saos-2 Cells and Human Colorectal Carcinoma HCT-116 Cells

INTRODUCTION

Increased colorectal carcinoma (CRC) and osteosarcoma prevalence, low survival rate, poor prognosis, and the limitations of existing anticancer therapies like side effects of drugs, non-specificity, short half-life, etc., pose a need for novel anticancer drugs. Farnesol, an organic sesquiterpene compound, found in the essential oils of various plants has been shown to possess antioxidant, anti-inflammatory, and anticancer properties. However, the anticancer effect of farnesol against CRC and osteosarcoma has not yet been adequately elucidated.

AIM

The aim of the study was to analyze the anticancer effects of farnesol against human osteosarcoma and CRC cell lines.

MATERIALS AND METHODS

Human osteosarcoma (Saos-2) and colorectal carcinoma (HCT-116) cell lines were procured and cultured at 37oC and 5% CO2. The cells were treated with 10, 20, 40, 60, 80, and 100 µM/ml and 20, 40, 60, 80, 100, and 120 µM/ml of farnesol for 24 hours, respectively. 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide assay was performed to assess the cytotoxicity of farnesol on Saos-2 and HCT-116 cells. Acridine orange/ethidium bromide staining was carried out to analyze apoptosis. 4',6-diamidino-2-phenylindole staining was done to observe the nuclear changes. Dichloro-dihydro-fluorescein diacetate staining was performed to assess the farnesol-induced reactive oxygen species (ROS)-mediated cell death.

RESULTS

Farnesol reduced the viability and proliferation of Saos-2 and HCT-116 cells in a dose-dependent manner. Farnesol was able to alter the cellular and nuclear morphology of Saos-2 and HCT-116 cells, promoting cell death. Farnesol-induced apoptosis in human osteosarcoma and colorectal carcinoma cell lines. Early apoptosis was observed in farnesol-treated HCT-116 cells. Additionally, ROS-mediated apoptotic cell death was reported in Saos-2 cells.

CONCLUSION

Farnesol has the potential to induce cytotoxicity against human osteosarcoma and CRC cell lines.

PLGA-based drug delivery systems in treating bone tumors

Bone tumor has become a common disease that endangers human health. Surgical resection of bone tumors not only causes biomechanical defects of bone but also destroys the continuity and integrity of bone and cannot completely remove the local tumor cells. The remaining tumor cells in the lesion bring a hidden danger of local recurrence. To improve the chemotherapeutic effect and effectively clear tumor cells, traditional systemic chemotherapy often requires higher doses, and high doses of chemotherapeutic drugs inevitably cause a series of systemic toxic side effects, often intolerable to patients. PLGA-based drug delivery systems, such as nano delivery systems and scaffold-based local delivery systems, can help eliminate tumors and promote bone regeneration and therefore have more significant potential for application in bone tumor treatment. In this review, we summarize the research progress of PLGA nano drug delivery systems and PLGA scaffold-based local delivery systems in bone tumor treatment applications, expecting to provide a theoretical basis for developing novel bone tumor treatment strategies.

A new approach to the development and assessment of doxorubicin-loaded nanoliposomes for the treatment of osteosarcoma in 2D and 3D cell culture systems

Doxorubicin (DOX) is an effective anticancer drug used for the treatment of osteosarcoma. Liposomal nanocarriers for doxorubicin administration are now regarded as one of the most promising approaches to overcome multiple drug resistance and adverse side effects. The use of hydrogel as a 3D scaffold to mimic the cellular environment and provide comparable biological conditions for deeper investigations of cellular processes has attracted considerable attention. This study aimed to evaluate the impact of liposomal doxorubicin on the osteosarcoma cell line in the presence of alginate hydrogel as a three-dimensional scaffold. Different liposomal formulations based on cholesterol, phospholipids, and surfactants containing doxorubicin were developed using the thin-layer hydration approach to improve therapeutic efficacy. The final selected formulation was superficially modified using DSPE-mPEG2000. A three-dimensional hydrogel culture model with appropriate structure and porosity was synthesized using sodium alginate and calcium chloride as crosslinks for hydrogel. Then, the physical properties of liposomal formulations, such as mechanical and porosity, were characterized. The toxicity of the synthesized hydrogel was also assessed. Afterward, the cytotoxicity of nanoliposomes was analyzed on the Saos-2 and HFF cell lines in the presence of a three-dimensional alginate scaffold using the MTT assay. The results indicated that the encapsulation efficiency, the amount of doxorubicin released within 8 h, the mean size of vesicles, and the surface charge were 82.2%, 33.0%, 86.8 nm, and -4.2 mv, respectively. As a result, the hydrogel scaffolds showed sufficient mechanical resistance and suitable porosity. The MTT assay demonstrated that the synthesized scaffold had no cytotoxicity against cells, while nanoliposomal DOX exhibited marked toxicity against the Saos-2 cell line in the 3D culture medium of alginate hydrogel compared to the free drug in the 2D culture medium. Our research showed that the 3D culture model physically resembles the cellular matrix, and nanoliposomal DOX with proper size could easily penetrate into cells and cause higher cytotoxicity compared to the 2D cell culture.

Clinical-radiomics models based on plain X-rays for prediction of lung metastasis in patients with osteosarcoma

OBJECTIVES

Osteosarcoma (OS) is the most common primary malignant bone tumor in adolescents. Lung metastasis (LM) occurs in more than half of patients at different stages of the disease course, which is one of the important factors affecting the long-term survival of OS. To develop and validate machine learning radiomics model based on radiographic and clinical features that could predict LM in OS within 3 years.

METHODS

486 patients (LM = 200, non-LM = 286) with histologically proven OS were retrospectively analyzed and divided into a training set (n = 389) and a validation set (n = 97). Radiographic features and risk factors (sex, age, tumor location, etc.) associated with LM of patients were evaluated. We built eight clinical-radiomics models (k-nearest neighbor [KNN], logistic regression [LR], support vector machine [SVM], random forest [RF], Decision Tree [DT], Gradient Boosting Decision Tree [GBDT], AdaBoost, and extreme gradient boosting [XGBoost]) and compared their performance. The area under the receiver operating characteristic curve (AUC) and accuracy (ACC) were used to evaluate different models.

RESULTS

The radscore, ALP, and tumor size had significant differences between the LM and non-LM groups (t_radscore = -5.829, χ²_ALP = 97.137, t_size = -3.437, P < 0.01). Multivariable LR analyses showed that ALP was an important indicator for predicting LM of OS (odds ratio [OR] = 7.272, P < 0.001). Among the eight models, the SVM-based clinical-radiomics model had the best performance in the validation set (AUC = 0.807, ACC = 0.784).

CONCLUSION

The clinical-radiomics model had good performance in predicting LM in OS, which would be helpful in clinical decision-making.

Targeting Intratibial Osteosarcoma Using Water-Soluble Copolymers Conjugated to Collagen Hybridizing Peptides

Osteosarcoma (OS) is the most common form of primary malignant bone cancer in adolescents. Over the years, OS prognosis has greatly improved due to adjuvant and neoadjuvant (preoperative) chemotherapeutic treatment, increasing the chances of successful surgery and reducing the need for limb amputation. However, chemotherapeutic treatment to treat OS is limited by off-target toxicities and requires improved localization at the tumor site. Collagen, the main constituent of bone tissue, is extensively degraded and remodeled in OS, leading to an increased availability of denatured (monomeric) collagen. Collagen hybridizing peptides (CHPs) comprise a class of peptides rationally designed to selectively bind to denatured collagen. In this work, we have conjugated CHPs as targeting moieties to water-soluble N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers to target OS tumors. We demonstrated increased accumulation of collagen-targeted HPMA copolymer-CHP conjugates compared to nontargeted HPMA copolymers, as well as increased retention compared to both nontargeted copolymers and CHPs, in a murine intratibial OS tumor model. Furthermore, we used microcomputed tomography analysis to evaluate the bone microarchitecture and correlated bone morphometric parameters (porosity, bone volume, and surface area) with maximum accumulation (Smax) and accumulation at 168 h postinjection (S168) of the copolymers at the tumor. Our results provide the foundation for the use of HPMA copolymer-CHP conjugates as targeted drug delivery systems in OS tumors.

Exosome-Functionalized, Drug-Laden Bone Substitute along with an Antioxidant Herbal Membrane for Bone and Periosteum Regeneration in Bone Sarcoma

Developing advanced methods for effective bone reconstructive strategies in case of critical bone defects caused by tumor resection, trauma, and other implant-related complications remains a challenging problem in orthopedics. In the clinical management of bone diseases, there is a paradigm shift in using local drugs at the injury site; however, the dead space created during the surgical debridement of necrotic bone and soft tissues (periosteum and underlying muscle) leads to ineffective bone formation, thereby leading to secondary complications, and thus calls for better regenerative approaches. In this study, we have utilized an exosome-functionalized doxorubicin-loaded biodegradable nanocement (NC)-based carrier along with a Cissus quadrangularis (CQ) extract-laden antioxidant herbal membrane for simultaneously managing the periosteum as well as bone formation in the tumor resection model of osteosarcoma. We initially evaluated the efficacy of scaffolds for in vitro mineralization and bone formation. To examine the in vivo effectiveness, we developed a human osteosarcoma cell line (Saos-2)-induced tumor xenograft model with a critical-sized bone defect. The findings revealed that doxorubicin released from NC was successful in killing the tumor cells and was present even after 30 days of implantation. Additionally, the incorporation of exosomes aided the bone formation, resulting in around a 2.6-fold increase in the bone volume compared to the empty group as evaluated by micro-CT. The herbal membrane assisted in the development of periosteum and mineralizing bone callous as validated through histological and immunofluorescence analysis. Thus, our findings describe a one-step biomaterial-based cell-free approach to regenerate bone in osteosarcoma and prevent further fracture due to the complete development of periosteum and lost bone.

Berberine inhibits the growth of osteosarcoma through modulating MMP/NM-23 and MAPK/JNK signal pathways

OBJECTIVE

To investigate the effects and mechanisms of berberine (BBR) on the migration, invasion, proliferation and apoptosis of osteosarcoma cells in vitro.

METHODS

Proliferation of MG-63 and U2OS cells was measured by the CCK-8 assay. Cells migration was examined by wound-healing assay. The invasion and metastasis of cells were evaluated by transwell invasion assay. Cells apoptosis was determined by the flow cytometry. Caspase-3 activity in MG-63 and U2OS cells was measured, and Western blot was used to measure the levels of Bax, Bcl-2, MMP-2 and MMP-9 in cells. In addition, the osteosarcoma graft tumor model of mice was established. The tumorigenesis of MG-63 cells in nude mice was compared among three groups. Immunohistochemistry assay was used to measure the levels of MMP-2, MMP-9 and NM-23 in tumor tissue.

RESULTS

It was showed that BBR inhibited the proliferation of MG-63 and U2OS cells in vitro in time- and concentration-dependent manners. Moreover, BBR reduced the cells migration and invasion, also down-regulated the expressions of MMP-2 and MMP-9. BBR also inhibited the cells apoptosis by down-regulating the expression of Bcl-2 and up-regulating the expression of Bax. In nude mice, BBR obviously inhibited the tumorigenesis of MG-63 cells. Compared with the negative group, BBR decreased the levels of MMP-2 and MMP-9 and increased the level of NM-23. The molecular mechanism was associated with activation of the MAPK/JNK signal transduction pathway.

CONCLUSIONS

BBR significantly regulates the biological behaviors of osteosarcoma cells and inhibits the growth of osteosarcoma. The molecular mechanism may be associated with the modulation of MMP/NM-23 and MAPK/JNK signals. BBR may be a potential drug for the treatment of osteosarcoma.

Up-regulation of Core 1 Beta 1, 3-Galactosyltransferase Suppresses Osteosarcoma Growth with Induction of IFN-γ Secretion and Proliferation of CD8+ T Cells

AIM

Abnormal glycosylation often occurs in tumor cells. T-synthase (core 1 beta 1,3- galactosyltransferase, C1GALT1, or T-synthase) is a key enzyme involved in O-glycosylation. Although T-synthase is known to be important in human tumors, the effects of T-synthase and T-antigen on human tumor responses remain poorly defined.

METHODS

In this study, a T-synthase-specific short hairpin RNA (shRNA) or T-synthase-specific eukaryotic expression vector(pcDNA3.1(+)) was transfected into murine Osteosarcoma LM8 cells to assess the effects of T-synthase on T cells and cytokines.

RESULTS

The up-regulation of T-synthase promoted the proliferation of osteosarcoma cells in vitro, but it promoted the proliferation of tumor initially up to 2-3 weeks but showed significant growth inhibitory effect after 3 weeks post-implantation in vivo. Osteosarcoma cells with high T-synthase expression in vitro promoted the proliferation and inhibited the apoptosis of CD8+ T cells. Further, T-synthase upregulation promoted CD8+ T-cell proliferation and the increased production of CD4+ T cell-derived IFN-γ cytokines to induce the increased tumor lethality of CTLs.

CONCLUSION

Our data suggest that high T-synthase expression inhibits tumor growth by improving the body's anti-tumor immunity. Therefore, using this characteristic to prepare tumor cell vaccines with high immunogenicity provides a new idea for clinical immunotherapy of osteosarcoma.

Research of the Active Components and Potential Mechanisms of Qingfei Gujin Decoction in the Treatment of Osteosarcoma Based on Network Pharmacology and Molecular Docking Technology

Aim. Qingfei Gujin Decoction (QGD) has been shown to be effective against osteosarcoma. This research was aimed at investigating the main active ingredients and potential mechanisms of QGD acting on osteosarcoma through network pharmacology and molecular docking techniques. Methods. The active ingredients and targets of QGD were screened from the TCMSP database, and the predicted targets were obtained from the PharmMapper database. Meanwhile, the targets of osteosarcoma were collected using OMIM, PharmGKB, and DisGeNET databases. Then, GO and KEGG enrichment analyses were performed by RStudio. PPI and drug-ingredient-target networks were constructed using Cytoscape 3.2.1 to screen the major active ingredients, key networks, and targets. Finally, molecular docking of key genes and their regulatory active ingredients was performed using AutoDockTools 1.5.6 software. Results. 38 active ingredients were collected, generating 89 cross-targets; quercetin, luteolin, β-sitosterol, and kaempferol were the main active ingredients of QGD acting on osteosarcoma, and major signaling pathways such as PI3K-Akt signaling pathway, MAPK signaling pathway, and IL-17 signaling pathway were observed. TP53, SRC, and ESR1 were identified as key proteins that docked well with their regulated compounds. Conclusion. QGD is effective against osteosarcoma through multicomponent, multitarget, and multipathway. This study was helpful for finding effective targets and compounds for osteosarcoma treatment.

Regulatory mechanism of Scutellaria baicalensis Georgi on bone cancer pain based on network pharmacology and experimental verification

Context

Scutellaria baicalensis Georgi (SBG) may relieve bone cancer pain (BCP) by regulating cell proliferation, angiogenesis, and apoptosis.

Objective

The mechanism of SBG in the treatment of BCP remains to be further explored.

Methods

The active compounds and targets of SBG were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and SwissTargetPrediction databases. BCP-related targets were screened from NCBI and GeneCards databases. Additionally, Cytoscape software was applied to construct network diagrams, and OmicShare platform was used to enrich Gene Ontology (GO) and pathways. Finally, the verification of active compounds and core targets was performed based on quantitative real-time PCR (qRT-PCR).

Results

Interestingly, we identified baicalein and wogonin as the main active components of SBG. A total of 41 SBG targets, including VEGFA, IL6, MAPK3, JUN and TNF, were obtained in the treatment of BCP. In addition, pathways in cancer may be an essential way of SBG in the treatment of BCP. Experimental verification had shown that baicalein and wogonin were significantly related to BCP core targets.

Conclusions

The active components of SBG have been clarified, and the mechanism of the active components in treating BCP has been predicted and verified, which provides an experimental and theoretical basis for the in-depth elucidation of the pharmacodynamics material basis and mechanism of SBG.

Ferroptosis in osteosarcoma: A promising future

The incidence of osteosarcoma (OS) is increasing year by year, and the prognosis of patients with advanced OS is extremely poor due to the tendency of recurrence and chemotherapy resistance after surgery. Ferroptosis is a novel form of programmed cell death (PCD) that kills cells through iron-dependent lipid peroxidation. Current studies have shown that ferroptosis is closely related to OS and could reduce chemotherapy resistance to a certain extent, which has great therapeutic potential. In this paper, we review the regulatory mechanism of ferroptosis and its research progress in OS, hoping to provide new help for the clinical treatment of OS.

LncRNA CASC9 promotes cell proliferation and invasion in osteosarcoma through targeting miR-874-3p/SOX12 axis

BACKGROUND

Osteosarcoma (OS) is a common primary malignant bone tumor. This study aimed to explore the biological role of long on-coding RNA (lncRNA) CASC9 and its regulatory mechanism in OC.

METHODS

The CASC9 expressions in OS cells and tissues were measured using qRT-PCR. The functional role of CASC9 in OC was studied using MTT assay, colony formation assay, transwell invasion assay, and xenograft tumor assay. In addition, the mechanism of CASC9 function was determined using luciferase reporter assay. Western blot was used to analyze protein expressions in our paper.

RESULTS

LncRNA CASC9 was found to be up-regulated in OS. Knockdown of CASC9 inhibited the proliferation and invasion of OS cells. Besides, miR-874-3p was identified as the target of CASC9, and SOX12 acted as a potential target of miR-874-3p. The down-regulation of miR-874-3p recovered the reduction in cell invasion and proliferation in vitro which were induced by CASC9 knockdown and delayed the tumor progression in vivo.

CONCLUSION

LncRNA CASC9 promotes cell proliferation and invasion in OS via miR-874-3p/SOX12 axis. Our study might provide novel biomarkers and potential therapeutic targets for OS treatment.

The Combination of Anlotinib and Gemcitabine/Docetaxel in Patients with Metastatic Osteosarcoma Who Have Failed Standard Chemotherapy

Purpose

The options for the second-line treatment of metastatic osteosarcoma are still limited. Anlotinib is a multi-kinase inhibitor which has shown promising efficacy and good tolerability in various cancer types. This retrospective study was conducted to evaluate the efficacy and safety of anlotinib combined with gemcitabine/docetaxel (GD) in patients with metastatic osteosarcoma who have failed first-line chemotherapy.

Patients and Methods

The data of patients who received anlotinib combined with GD or GD were collected. The primary endpoint was progression-free survival. Secondary endpoints included objective response rate and safety.

Results

From July 2013 to November 2020, a total of 32 patients were enrolled, 13 received anlotinib combined with GD and 19 received GD. Median PFS was 9.0 months (95% CI 6.7-39.1) in the combination group and 5.0 months (95% CI 1.2-6.7) in the chemotherapy group. ORR were 38.4% and 15.8%, DCR were 69.2% and 38.1% in the combination and chemotherapy group, respectively. The most common adverse events included fatigue (78.9% in the combination group vs 69.2% in the chemotherapy group), hypertension (46.2% vs 10.5%), diarrhea (38.5% vs 21.1%), hypothyroidism (38.5% vs 15.8%), neutropenia (23.1% vs 36.8%) and AST elevation (30.8% vs 21.1%). The most common grade 3 or worse adverse events included hand-foot reaction (7.7% vs 5.3%), hypothyroidism (15.4% vs 0), neutropenia (0 vs 10.5%).

Conclusion

The combination of anlotinib and GD showed favorable efficacy with manageable toxicities compared with GD in the second-line treatment for metastatic osteosarcoma. This combination therapy deserves further investigations in patients with osteosarcoma.

ICSBP-induced PD-L1 enhances osteosarcoma cell growth

Background

Interferon (IFN) consensus sequence binding protein (ICSBP) is a transcription factor induced by IFN-γ. We previously reported that ICSBP expression promotes osteosarcoma progression by enhancing transforming growth factor-β signaling. In cancer cells, programmed death-ligand 1 (PD-L1) contributes to immune escape and may also be involved in tumor progression. Because IFN-γ induces the expression of both ICSBP and PD-L1, we explored the association between ICSBP and PD-L1 expression in terms of osteosarcoma progression.

Methods

Three osteosarcoma cell lines (Saos2, U2OS, and 143B) were employed. Gene expression was measured by qRT-PCR, and protein levels were assessed by immunoblotting. PD-L1 expression was evaluated in cells overexpressing ICSBP and in ICSBP knockdown cells. The effects of PD-L1 expression on cell growth were examined by MTS assays, Incucyte analysis, soft agar assays, and three-dimensional (3D) culture. Cell cycle and apoptosis were evaluated by FACS analysis of cells stained with propidium iodide (PI) and annexin V/PI, respectively. The antitumor effects of PD-L1 knockdown without or with doxorubicin treatment were evaluated in vivo in nude mice bearing ICSBP-overexpressing 143B cell xenograft. The clinical relevance of PD-L1 and ICSBP expression was evaluated immunohistochemically using a human osteosarcoma microarray and through analysis of publicly available data using Gene Expression Profiling Interactive Analysis2.

Results

ICSBP overexpression upregulated PD-L1 expression in all three cell lines, whereas ICSBP knockdown decreased the PD-L1 expression. PD-L1 knockdown attenuated the cell growth and reduced colony-forming capacity in both soft agar assays and 3D culture. PD-L1 knockdown increased apoptosis and induced G2/M arrest, which was associated with decreased expression of survivin, cyclin-dependent kinase 4 (CDK4), cyclin E, and cyclin D1 expression and increased the expression of p27, phosphorylated Cdc2, and phosphorylated Wee1. PD-L1 knockdown decreased the growth of tumor xenografts and increased the doxorubicin sensitivity of ICSBP-overexpressing 143B cells both in vitro and in vivo. PD-L1 was expressed in human osteosarcoma tissues, and its expression was moderately correlated with that of ICSBP in osteosarcoma patients.

Conclusion

ICSBP regulates PD-L1 expression in osteosarcoma cells, and PD-L1 knockdown combined with doxorubicin treatment could represent a strategy for controlling osteosarcoma expressing ICSBP.

The Expression Pattern of Non-apoptotic Cell Death Pathway in Osteosarcoma: Necroptosis and Autophagy as Backup Mechanisms for Therapeutics Strategy

Background: Among the primary bone tumors, osteosarcoma accounts for a malignant tumor with a high rate of progression and poor prognosis. Despite the achievement of combined therapy regimens in improving patients’ overall survival, patients with osteosarcoma confront the chemoresistance obstacle. Objectives: This study aimed at determining the expression pattern of autophagy and necroptosis pathways mediators in osteosarcoma tumors. Methods: The expression level of autophagy main mediators such as autophagy-associated protein 5 (ATG5), Beclin 1 (BECN1), and microtubule-associated protein 1A/1B-light chain 3 (LC3), necroptosis biomarkers such as receptor-interacting protein kinases (RIPK1 and RIPK3), and mixed lineage kinase domain-like (MLKL) were evaluated in 80 bone tissues including 60 bone tumors (40 malignant tumors and 20 benign tumors) and 20 margin tissues, using real-time PCR. The correlations of gene expression levels with the patient’s clinical and pathological features were considered. Results: Based on our data, ATG5, BECN1 and LC3 expression were down-regulated in osteosarcoma tumors compared to margin tissues. Also, malignant osteosarcoma tumors showed a significant decrease in the expression level of RIPK1 and MLKL as necroptosis regulators, which revealed a correlation with tumor malignancy. In addition, the higher expression levels of BECN1, LC3, RIPK1, and MLKL were observed in tumor tissues of patients under the chemotherapy regimen, indicating the relevance of autophagy and necroptosis pathways with the patient’s response to therapy. Conclusions: Reduction in the expression level of autophagy and necroptosis mediators in high-grade osteosarcoma tumors indicates the possible impact of these pathways on the rate of proliferation and growth of osteosarcoma tumor cells and can emphasize the importance of cell death alternative pathways for treatment when apoptosis machinery is mutated and cause chemoresistance.

WeChat-platform-based education and care program as a candidate approach to relieve anxiety, depression, and post-traumatic stress disorder in parents of pediatric and adolescent patients with osteosarcoma

Background

WeChat is the main social platform in China, characterized by its versatility and ease of communication. This study aimed to explore the effect of a WeChat-platform-based education and care (WBEC) program on relieving anxiety, depression, and post-traumatic stress disorder (PTSD) in parents of pediatric and adolescent patients with osteosarcoma.

Methods

In total, 48 patients and 86 parents were enrolled in this randomized, controlled study and then assigned to the WBEC program (24 patients and 45 parents) and the usual education and care (UEC) program (22 patients and 41 parents) for 6 months as a 1:1 ratio.

Results

Parents in the WBEC group had lower Hospital Anxiety and Depression Scale (HADS) for anxiety (HADS-A) scores at M3 (7.8 ± 2.2 vs. 9.1 ± 2.5; p = 0.010) and M6 (7.7 ± 2.5 vs. 8.9 ± 2.4; p = 0.027) when compared to the UEC group, while anxiety rate was only decreased at M3 (43.2% vs. 63.4%; p = 0.049) in the WBEC group. Meanwhile, parental HADS for depression (HADS-D) scores were reduced at M3 (7.0 ± 2.0 vs. 8.0 ± 2.1; p = 0.047) and M6 (7.1 ± 1.9 vs. 8.0 ± 2.4; p = 0.045) in the WBEC group when compared with the UEC group; while depression rate remained the same. Parental Impact of Event Scale-Revised (IES-R) scores were slightly reduced among the WBEC group at M6 when compared with the UEC group [12.0 (interquartile range (IQR): 10.0–20.8] vs. 15.0 (IQR: 9.5–25.0; p = 0.077)], but not statistically significant.

Conclusion

WeChat-platform-based education and care is considered a feasible intervention to reduce anxiety and depression in parents of pediatric and adolescent patients with osteosarcoma, while also providing mild relief from PTSD.

Colchicine as a novel drug for the treatment of osteosarcoma through drug repositioning based on an FDA drug library

Background

Colchicine is a traditional medication that is currently approved to treat gout and familial Mediterranean fever (FMF). However, colchicine has a wide range of anti-inflammatory activities, and several studies have indicated that it may be useful in a variety of other conditions, such as rheumatic disease, cardiac disease, and cancer. Osteosarcoma, the most common type of bone sarcoma, is derived from primitive bone-forming mesenchymal cells. In this study, we investigated whether colchicine could be used to treat osteosarcoma through the regulation of cell cycle signaling.

Methods

Two human osteosarcoma cell lines, U2OS and Saos-2, were used. A clonogenic assay was used to determine the antiproliferative effects of colchicine on osteosarcoma cells. Reactive oxygen species (ROS) production and apoptosis were measured by flow cytometry. Migration and invasion assays were performed to investigate the inhibitory effects of colchicine. The signaling pathways related to colchicine treatment were verified by GO biological process (GOBP) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses.

Results

Colchicine was selected as the lead compound based on the results of initial screening and cell viability assays conducted in Saos-2 and U2Os cells. Colchicine reduced the viability of Saos-2 and U2OS cells in a concentration-dependent manner. It also significantly inhibited colony-forming ability and induced ROS production and apoptosis. It also inhibited the migration and invasion of both Saos-2 and U2OS cells. GOBP and KEGG enrichment analyses indicated the involvement of microtubule-based processes and cancer-related pathways.

Conclusions

These findings suggest that colchicine has therapeutic potential in osteosarcoma.

Integrated analysis of anti-tumor roles of BAP1 in osteosarcoma

Background

This study aims to screen out differentially expressed genes (DEGs) regulated by BRCA1-associated protein 1 (BAP1) in osteosarcoma cells, and to analyze their biological functions.

Methods

The microarray dataset GSE23035 of BAP1-knockdown osteosarcoma cells was obtained from Gene Expression Omnibus (GEO) database, consisting of shControl, shBAP1#1 and shBAP1#2 samples. The DEGs between the BAP1-knockdown osteosarcoma cells and the untreated osteosarcoma cells were screened with limma package, and then subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Gene Set Enrichment Analysis (GSEA) was also performed for the three groups of samples. Hub genes in a protein-protein interaction (PPI) network of DEGs was filtered, and then subjected to prognostic analysis and correlation analysis with BAP1 in Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. Besides, the correlation between BAP1 and biological processes/pathways was analyzed by Gene Set Variation Analysis (GSVA) method and the correlation between BAP1 and immune infiltration by CIBERSORT and ESTIMATE methods. The roles of BAP1 in regulating proliferation and epithelial-mesenchymal transition (EMT) were validated by CCK-8 and western blot.

Results

58 upregulated DEGs and 81 downregulated DEGs were obtained with |logFC| ≥ 1 and adj.p < 0.05. Cell cycle, DNA repair, and focal adhesion were associated with BAP1 in datasets. Further, BAP1 was negatively correlated with naïve CD4 T cells infiltration. In vitro, BAP1 inhibited proliferation and EMT.

Conclusion

BAP1 might be a tumor suppressor in osteosarcoma and a promising therapeutic target.

Mesenchymal Stem Cell Derived Exosomes as Nanodrug Carrier of Doxorubicin for Targeted Osteosarcoma Therapy via SDF1-CXCR4 Axis

Purpose

The objective of this study was to investigate the antitumor activity, targeting capability, and mechanism of the developed nanodrug consisting of doxorubicin and exosome (Exo-Dox) derived from mesenchymal stem cells in vitro and in vivo.

Methods

The exosomes were isolated with Exosome Isolation Kit, and the Exo-Dox was prepared by mixing exosome with Dox-HCl, desalinizing with triethylamine and then dialyzing against PBS overnight. The exosome and Exo-Dox were examined by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). The antitumor activity, targeting capability, and mechanism of the developed Exo-Dox were evaluated by cell viability assay, histological and immunofluorescence analysis and in vivo imaging system.

Results

NTA results showed the size of the exosomes had increased from 141.6 nm to 178.1 nm after loading with doxorubicin. Compared with free Dox, the Exo-Dox exhibited higher cytotoxicity against osteosarcoma MG63 cells, HOS cells, and 143B cells than free Dox, the half-maximal inhibitory concentrations (IC50) of Dox, Exo-Dox were calculated to be 0.178 and 0.078 μg mL⁻¹ in MG63 cells, 0.294 and 0.109μg mL⁻¹ in HOS cells, 0.315 and 0.123 μg mL⁻¹ in 143B cells, respectively. The in vivo imaging showed that MSC derived Exo could serve as a highly efficient delivery vehicle for targeted drug delivery. The immunohistochemistry and histology analysis indicated that compared with the free Dox group, the Ki67-positive cells and cardiotoxicity in Exo-Dox group were significantly decreased.

Conclusion

Our results suggested that MSC-derived Exo could be excellent nanocarriers used to deliver chemotherapeutic drug Dox specifically and efficiently in osteosarcoma, resulting in enhanced toxicity against osteosarcoma and less toxicity in heart tissue. We further demonstrated the targeting capability of Exo was due to the chemotaxis of MSC-derived exosomes to osteosarcoma cells via SDF1-CXCR4 axis.

CircAGFG1 Promotes Osteosarcoma Progression and Stemness by Competing with miR-302a-3p to Upregulate the Expression of LATS2

This study aimed to investigate the effect of circRNA (circAGFG1) on the proliferation, migration, invasion, and cell stemness of osteosarcoma cells by targeting miR-302a to regulate LATS2. The expression of circAGFG1 in osteosarcoma cells and normal osteoblasts was detected by real-time fluorescent quantitative PCR (RT-qPCR). Cell proliferation, clone formation, and invasion were detected by CCK-8, clone formation, and cell invasion assays. In vivo tumor formation assay was used to detect the effect of circAGFG1 on tumor growth. The expression level of circAGFG1 was upregulated in osteosarcoma cells. The downregulation of circAGFG1 inhibited the proliferation, invasion, and migration of osteosarcoma cells. The overexpression of circAGFG1 enhanced the stemness of osteosarcoma cells. CircAGFG1 was specifically bound to miR-302a to regulate the expression activity of miR-302a. MiR-302a specifically bound to the 3'UTR of LATS2 and inhibited the expression of LATS2. The overexpression of miR-302a reversed the effect of circAGFG1 on the proliferation, invasion, and migration of osteosarcoma cells. CircAGFG1 regulated the expression of LATS2 by miR-302a, thereby regulating the proliferation, migration, and invasion of osteosarcoma cells.

Graphene Oxide Nanoplatforms to Enhance Cisplatin-Based Drug Delivery in Anticancer Therapy

Chemotherapeutics such as platinum-based drugs are commonly used to treat several cancer types, but unfortunately, their use is limited by several side effects, such as high degradation of the drug before entering the cells, off-target organ toxicity and development of drug resistance. An interesting strategy to overcome such limitations is the development of nanocarriers that could enhance cellular accumulation in target cells in addition to decreasing associated drug toxicity in normal cells. Here, we aim to prepare and characterize a graphene-oxide-based 2D nanoplatform functionalised using highly branched, eight-arm polyethylene-glycol, which, owing to its high number of available functional groups, offers considerable loading capacity over its linear modalities and represents a highly potent nanodelivery platform as a versatile system in cancer therapy. The obtained results show that the GO@PEG carrier allows for the use of lower amounts of Pt drug compared to a Pt-free complex while achieving similar effects. The nanoplatform accomplishes very good cellular proliferation inhibition in osteosarcoma, which is strictly related to increased cellular uptake. This enhanced cellular internalization is also observed in glioblastoma, although it is less pronounced due to differences in metabolism compared to osteosarcoma. The proposed GO@PEG nanoplatform is also promising for the inhibition of migration, especially in highly invasive breast carcinoma (i.e., MDA-MB-231 cell line), neutralizing the metastatic process. The GO@PEG nanoplatform thus represents an interesting tool in cancer treatment that can be specifically tailored to target different cancers.

Analyzing BMP2, FGFR, and TGF Beta Expressions in High-Grade Osteosarcoma Untreated and Treated Autografts Using Proteomic Analysis

In the last few decades, biological reconstruction techniques have improved greatly for treating high-grade osteosarcoma patients. To conserve the limb, and its function the affected tumor-bearing bones have been treated using liquid nitrogen and irradiation processes that enable the removal of entire tumors from the bone, and these treated autografts can be reconstructed for the patients. Here, we focus on the expressions of the growth factor family proteins from the untreated and treated autografts that play a crucial role in bone union, remodeling, and regeneration. In this proteomic study, we identify several important cytoskeletal, transcriptional, and growth factor family proteins that showed substantially low levels in untreated autografts. Interestingly, these protein expressions were elevated after treating the tumor-bearing bones using liquid nitrogen and irradiation. Therefore, from our preliminary findings, we chose to determine the expressions of BMP2, TGF-Beta, and FGFR proteins by the target proteomics approach. Using a newly recruited validation set, we successfully validate the expressions of the selected proteins. Furthermore, the increased growth factor protein expression after treatment with liquid nitrogen may contribute to bone regeneration healing, assist in faster recovery, and reduce local recurrence and metastatic spread in high-grade sarcoma patients.

Apigenin Suppresses the Warburg Effect and Stem-like Properties in SOSP-9607 Cells by Inactivating the PI3K/Akt/mTOR Signaling Pathway

Osteosarcoma (OS) is a prevalent primary malignant bone tumor that commonly occurs in children and adolescents. Apigenin (4′,5,7-trihydroxyflavone) is one of the most researched phenolic compounds that exhibits antitumor effects in several cancers. The aim of the current study was to investigate the effect and underlying mechanisms of apigenin on OS. To address this, OS cells (SOSP-9607) were treated with different concentrations of apigenin. The proliferation, migration, invasion, stem-like properties, and Warburg effect of apigenin-treated OS cells were evaluated. Apigenin was found to suppress the proliferation of SOSP-9607 cells and inhibit epithelial-mesenchymal transition, as indicated by decreased number of migrated and invaded cells, decreased protein expression of vimentin, and increased protein expression of E-cadherin. Additionally, apigenin suppressed tumorsphere formation and reduced the proportion of SOSP-9607 cells with positive expression of the stem cell-related markers Nanog and OCT-4. Apigenin inhibited the Warburg effect in SOSP-9607 cells, as demonstrated by decreased glucose and lactic acid levels, increased citrate and ATP levels, and downregulation of GLUT1, HK1, and LDHA, which are metabolism-related enzymes related to the Warburg effect. Moreover, apigenin inhibited the phosphorylation of PI3K, Akt, and mTOR in SOSP-9607 cells. Collectively, these results indicate that apigenin suppresses the Warburg effect and stem-like properties in SOSP-9607 cells, which may be mediated by PI3K/Akt/mTOR signaling, thus, providing a novel strategy for OS treatment.

Mineral Nanomedicine to Enhance the Efficacy of Adjuvant Radiotherapy for Treating Osteosarcoma

It is vital to remove residual tumor cells after resection to avoid the recurrence and metastasis of osteosarcoma. In this study, a mineral nanomedicine, europium-doped calcium fluoride (CaF₂:Eu) nanoparticles (NPs), is developed to enhance the efficacy of adjuvant radiotherapy (i.e., surgical resection followed by radiotherapy) for tumor cell growth and metastasis of osteosarcoma. In vitro studies show that CaF₂:Eu NPs (200 μg/mL) exert osteosarcoma cell (143B)-selective toxicity and migration-inhibiting effects at a Eu dopant amount of 2.95 atomic weight percentage. These effects are further enhanced under X-ray irradiation (6 MeV, 4 Gy). Furthermore, in vivo tests show that intraosseous injection of CaF₂:Eu NPs and X-ray irradiation have satisfactory therapeutic efficacy in controlling primary tumor size and inhibiting primary tumor metastasis. Overall, our results suggest that CaF₂:Eu NPs with their osteosarcoma cell (143B)-selective toxicity and migration-inhibiting effects combined with radiotherapy might be nanomedicines for treating osteosarcoma after tumor resection.

Different Cell Responses to Hinokitiol Treatment Result in Senescence or Apoptosis in Human Osteosarcoma Cell Lines

Hinokitiol is a tropolone-related compound isolated from the heartwood of cupressaceous plants. It is known to exhibit various biological functions including antibacterial, antifungal, and antioxidant activities. In the study, we investigated the antitumor activities of hinokitiol against human osteosarcoma cells. The results revealed that hinokitiol treatment inhibited cell viability of human osteosarcoma U-2 OS and MG-63 cells in the MTT assay. Further study revealed that hinokitiol exposure caused cell cycle arrest at the S phase and a DNA damage response with the induction of γ-H2AX foci in both osteosarcoma cell lines. In U-2 OS cells with wild-type tumor suppressor p53, we found that hinokitiol exposure induced p53 expression and cellular senescence, and knockdown of p53 suppressed the senescence. However, in MG-63 cells with mutated p53, a high percentage of cells underwent apoptosis with cleaved-PARP expression and Annexin V staining after hinokitiol treatment. In addition, up-regulated autophagy was observed both in hinokitiol-exposed U-2 OS and MG-63 cells. As the autophagy was suppressed through the autophagy inhibitor chloroquine, hinokitiol-induced senescence in U-2 OS cells was significantly enhanced accompanying more abundant p53 expression. In MG-63 cells, co-treatment of chloroquine increased hinokitiol-induced apoptosis and decreased cell viability of the treated cells. Our data revealed that hinokitiol treatment could result in different cell responses, senescence or apoptosis in osteosarcoma cell lines, and suppression of autophagy could promote these effects. We hypothesize that the analysis of p53 status and co-administration of autophagy inhibitors might provide more precise and efficacious therapies in hinokitiol-related trials for treating osteosarcoma.

Knowledge atlas and emerging trends on ncRNAs of osteosarcoma: A bibliometric analysis

BACKGROUND

Osteosarcoma is a common bone sarcoma that occurs in childhood and adolescence. Although research on non-coding RNAs (ncRNAs) of osteosarcoma has been developed rapidly in recent years, a specific bibliometric analysis on this topic has not yet been performed. The bibliometric analysis aims to summarize knowledge atlas, research hotspots, and emerging trends and to provide researchers with new perspectives in further studies.

METHODS

All publications regarding ncRNAs of osteosarcoma published from 2000 to 2021 were retrieved from the Web of Science Core Collection. Quantitative indicators including the number of publications and citations, H-index, and journal citation reports were analyzed by using Excel 2019 and R software. VOSviewer and CiteSpace were used to analyze the cooperation among countries/institutions/journals/authors and the co-occurrence of keywords, keywords bursts, and references.

RESULTS

A total of 3206 publications were extracted. A significant growth trend in the annual number of publications over the past 22 years is revealed (R ² = 0.999). The most prolific country and institution were China (2260) and Shanghai Jiao Tong University (134), respectively. Professors Wang W and Liu W contributed the most to this field. The keywords were stratified into six clusters: Cluster 1 (apoptosis and growth), Cluster 2 (cancer and progression), Cluster 3 (microRNAs and downregulation), Cluster 4 (genes and differentiation), Cluster 5 (expression and biological functions), and Cluster 6 (metastasis). The long non-coding RNAs and circular RNAs have been considered as an important research hotspot in the near future.

CONCLUSION

This study offers a scientific perspective on ncRNAs of osteosarcoma and provides researchers with valuable information to understand the knowledge structure and to identify emerging trends in this field.

Gemcitabine-Ibandronate Conjugate Enables the Bone-Targeted Combination Therapy in Bone Cancer: Synthesis and Efficacy in Combination with Docetaxel

Patients with cancer-induced bone disease, including primary bone cancers such as osteosarcoma (OS) and metastases from other tissues of origin, present a high unmet medical need. We present a potential therapeutic approach built upon a proven bone-targeting bisphosphonate conjugate platform with the known synergies of gemcitabine (GEM) and docetaxel (DTX). The synthesis of rationally designed GEM-IB, the conjugate of GEM-5'-phosphate with ibandronate (IB), is presented. GEM-IB as a single agent or in combination with DTX demonstrated reduced tumor burden, preservation of the bone architecture, and improved the survival in a murine model of OS. This is the first demonstration of a bone-targeting conjugate in combination with a second drug to create effective drug ratios in the bone compartment.

Extracellular Vesicles in Osteosarcoma: Antagonists or Therapeutic Agents?

Osteosarcoma (OS) is a skeletal tumor affecting mainly children and adolescents. The presence of distance metastasis is frequent and it is localized preferentially to the lung, representing the main reason for death among patients. The therapeutic approaches are based on surgery and chemotherapeutics. However, the drug resistance and the side effects associated with the chemotherapy require the identification of new therapeutic approaches. The understanding of the complex biological scenario of the osteosarcoma will open the way for the identification of new targets for its treatment. Recently, a great interest of scientific community is for extracellular vesicles (EVs), that are released in the tumor microenvironment and are important regulators of tumor proliferation and the metastatic process. At the same time, circulating extracellular vesicles can be exploited as diagnostic and prognostic biomarkers, and they can be loaded with drugs as a new therapeutic approach for osteosarcoma patients. Thus, the characterization of OS-related EVs could represent a way to convert these vesicles from antagonists for human health into therapeutic and/or diagnostic agents.

Involvement of the TGF-β Signaling Pathway in the Development of YAP-Driven Osteosarcoma Lung Metastasis

Background

The poor survival rate of patients with osteosarcoma (OS), specifically with metastases at diagnosis, undergoes the urgency to develop new therapeutic strategies. Although we recently demonstrated the key role of YAP/TEAD signaling in the growth of OS primary tumor, the molecular mechanisms by which YAP regulates metastases development remain poorly understood.

Methods

The molecular mechanisms by which YAP regulates metastases development were studied using an overexpression of mutated forms of YAP able or not able to interact with TEAD. Molecular signatures were identified using RNA-sequencing analysis and gene set enrichment. Interactions between YAP and Smad3 were studied using proximity ligation assay (PLA), immunoprecipitation, and promoter/specific gene assays. The involvement of the TGF-β pathway in the ability of YAP to stimulate metastatic development in vivo was studied using an inhibitor of the TGF-β cascade in a preclinical model of OS and in vitro on the ability of OS cells to migrate and invade.

Results

Our work shows that a high YAP expression is associated with the presence of lung metastases which predicts a poor prognosis. Molecular analysis indicates that TGF-β signaling is involved in YAP-driven osteosarcoma cell pro-migratory phenotype, epithelial mesenchymal transition, cell migration, and in vivo lung metastasis development. Regardless of its ability to bind to TEAD, YAP interacts with Smad3 and stimulates the transcriptional activity of TGF-β/Smad3, thereby enhancing the ability of TGF-β to stimulate lung metastasis development.

Conclusions

We demonstrated the crucial involvement of the TGF-β/Smad3 signaling pathway in YAP-driven lung metastasis development in OS.

The Clinical Significance of the Expression of FEN1 in Primary Osteosarcoma

PURPOSE

The aim of this research was to investigate the clinical significance of the expression of flap structure-specific endonuclease 1 (FEN1) in primary osteosarcoma.

METHODS

The expression of FEN1 was detected by immunohistochemistry analysis. The association of the expression of FEN1 in osteosarcoma with clinicopathological parameters was analyzed by using χ 2 test or Fisher's exact test. Survival analyses were performed by Kaplan-Meier method and Cox proportional hazards regression model.

RESULTS

Of the 40 osteosarcoma patients, 19 (47.5%) patients presented with FEN1 high expression, while in the non-neoplastic bone specimens, the FEN1 high expression was observed in 10% (3/30), the positive expression rate in osteosarcoma patients was significantly higher than that of non-neoplastic bone specimens (P< 0.01). Univariate analysis indicated that the progression-free survival (PFS) and overall survival (OS) were correlated with the expression level of FEN1 (PFS, P < 0.001; OS, P = 0.002), Enneking staging (PFS, P = 0.026; OS, P = 0.044) and chemotherapy response (PFS, P = 0.019; OS, P = 0.031). Multivariate analysis demonstrated that FEN1 expression was an independent prognostic factor for the PFS (HR = 4.73, P = 0.002) and OS (HR = 4.01, P = 0.038) of osteosarcoma patients.

CONCLUSION

This study showed that FEN1 was overexpressed in osteosarcoma patients and positively associated with poor prognosis of osteosarcoma patients. Further studies should focus on the relative mechanisms and the targeted FEN1 therapies for osteosarcoma.

Zeylenone synergizes with cisplatin in osteosarcoma by enhancing DNA damage, apoptosis, and necrosis via the Hsp90/AKT/GSK3β and Fanconi anaemia pathway

A safer and more effective combination strategy designed to enhance the efficacy and minimize the toxicity of cisplatin in osteosarcoma (OS) is urgently needed. Zeylenone (zey), a cyclohexene oxide compound, exerted an obvious inhibitory effect on several cancer cell lines and exhibited little cytotoxicity towards normal cells, enabling zey to play a unique role in combination therapy. Thus, the study aimed to determine whether the combination of zey and cisplatin produces synergistic antitumour effects on OS and to further explore molecular mechanisms. Initially, we found that zey potentiated the anti-osteosarcoma efficacy of cisplatin and exhibited synergistic interactions with cisplatin in vitro, which also were confirmed in vivo by using xenograft model. Mechanistically, zey and cisplatin synergistically induced DNA damage, cell cycle arrest, necrosis, and apoptosis in OS cells. Importantly, zey had a high binding affinity for Hsp90 and reduced the expression of Hsp90, which further induced the suppression of AKT/GSK3β signalling axis and the degradation of Fanconi anaemia (FA) pathway proteins. Thus, the Hsp90/AKT/GSK3β and FA pathway are the key to the synergism between zey and cisplatin. Overall, zey shows promise for development as a cisplatin chemosensitizer with clinical utility in restoring cisplatin sensitivity of cancer cells.

Efficient and Consistent Orthotopic Osteosarcoma Model by Cell Sheet Transplantation in the Nude Mice for Drug Testing

Osteosarcoma is a big challenge on clinical treatment. The breakthrough associated with osteosarcoma in basic research and translational research depends on the reliable establishment of an animal model, whereby mice are frequently used. However, a traditional animal modeling technique like tumor cell suspension injection causes batch dynamics and large mice consumption. Here, we suggested a novel approach in establishing an orthotropic osteosarcoma model in nude mice rapidly by cell sheet culture and transplantation. Our findings demonstrated that the 143b osteosarcoma cell sheet orthotopically implanted into the nude mice could form a visible mass within 10 days, whereas it took over 15 days for a similar amount of cell suspension injection to form a visible tumor mass. Living animal imaging results showed that a tumor formation rate was 100% in the cell sheet implantation group, while it was 67% in the cell suspension injection group. The formed tumor masses were highly consistent in both growth rate and tumor size. Massive bone destruction and soft tissue mass formation were observed from the micro CT analysis, suggesting the presence of osteosarcoma. The histopathological analysis demonstrated that the orthotropic osteosarcoma model mimicked the tumor bone growth, bone destruction, and the lung metastasis. These findings imply that such a cell sheet technology could be an appropriate approach to rapidly establish a sustainable orthotropic osteosarcoma model for tumor research and reduce mice consumption.

Niclosamide and Pyrvinium Are Both Potential Therapeutics for Osteosarcoma, Inhibiting Wnt-Axin2-Snail Cascade

Simple Summary

Epithelial–mesenchymal transition (EMT) regulated by Wnt signaling is known as a key mechanism of cancer progression. Although evidence has suggested that the oncogenic Wnt signaling pathway and EMT program are important in the progression of osteosarcoma, there is no known therapeutic drug targeting EMT for osteosarcoma. We investigated whether Axin2, an important EMT target, could be a suitable molecular target and biomarker for osteosarcoma. Furthermore, we showed that both niclosamide and pyrvinium target Axin2, and effectively induce EMT reversion in osteosarcoma cell lines. Our findings suggest an effective biomarker and potential EMT therapeutics for osteosarcoma patients.

Abstract

Osteosarcoma, the most common primary bone malignancy, is typically related to growth spurts during adolescence. Prognosis is very poor for patients with metastatic or recurrent osteosarcoma, with survival rates of only 20–30%. Epithelial–mesenchymal transition (EMT) is a cellular mechanism that contributes to the invasion and metastasis of cancer cells, and Wnt signaling activates the EMT program by stabilizing Snail and β-catenin in tandem. Although the Wnt/Snail axis is known to play significant roles in the progression of osteosarcoma, and the anthelmintic agents, niclosamide and pyrvinium, have been studied as inhibitors of the Wnt pathway, their therapeutic effects and regulatory mechanisms in osteosarcoma remain unidentified. In this study, we show that both niclosamide and pyrvinium target Axin2, resulting in the suppression of EMT by the inhibition of the Wnt/Snail axis in osteosarcoma cells. Axin2 and Snail are abundant in patient samples and cell lines of osteosarcoma. The treatment of niclosamide and pyrvinium inhibits the migration of osteosarcoma cells at nanomolar concentrations. These results suggest that Axin2 and Snail are candidate therapeutic targets in osteosarcoma, and that anthelminthic agents, niclosamide and pyrvinium, may be effective for osteosarcoma patients.

The smac mimetic LCL161 targets established pulmonary osteosarcoma metastases in mice

Osteosarcoma is the most common form of primary bone cancer and frequently metastasizes to the lungs. Current therapies fail to successfully treat over two thirds of patients with metastatic osteosarcoma, so there is an urgent imperative to develop therapies that effectively target established metastases. Smac mimetics are drugs that work by inhibiting the pro-survival activity of IAP proteins such as cIAP1 and cIAP2, which can be overexpressed in osteosarcomas. In vitro, osteosarcoma cells are sensitive to a range of Smac mimetics in combination with TNFα. This sensitivity has also been demonstrated in vivo using the Smac mimetic LCL161, which inhibited the growth of subcutaneous and intramuscular osteosarcomas. Here, we evaluated the efficacy of LCL161 using mice bearing osteosarcoma metastases without the presence of a primary tumor, modeling the scenario in which a patient's primary tumor had been surgically removed. We demonstrated the ability of LCL161 as a single agent and in combination with doxorubicin to inhibit the growth of, and in some cases eliminate, established pulmonary osteosarcoma metastases in vivo. Resected lung metastases from treated and untreated mice remained sensitive to LCL161 in combination with TNFα ex vivo. This suggested that there was little to no acquired resistance to LCL161 treatment in surviving osteosarcoma cells and implied that tumor microenvironmental factors underlie the observed variation in responses to LCL161.

MicroRNA-432-5p regulates sprouting and intussusceptive angiogenesis in osteosarcoma microenvironment by targeting PDGFB

Osteosarcoma (OS) is a type of bone tumor conferred with high metastatic potential. Attainable growth of tumors necessitates functional vasculature mediated by sprouting angiogenesis (SA) and intussusceptive angiogenesis (IA). However, the regulation of IA and SA is still unclear in OS. To understand the mechanisms adopted by OS to induce angiogenesis, initially, we assessed the expression profile of a set of miRNAs' in both OS cells (SaOS2 and MG63) and normal bone cells. Amongst them, miR-432-5p was found to be highly downregulated in OS. The functional role of miR-432-5p in OS was further analyzed using miR-432-5p mimic/inhibitor. Platelet-derived growth factor-B (PDGFB) was found to be a putative target of miR-432-5p and it was further confirmed that the PDGFB 3'UTR is directly targeted by miR-432-5p using the luciferase reporter gene system. PDGFB was found to be secreted by OS to regulate angiogenesis by targeting the cells in its microenvironment. The conditioned medium obtained from miR-432-5p mimic transfected MG63 and SaOS2 cells decreased cell viability, proliferation, migration, and aorta ring formation in endothelial cells. The miRNA mimic/inhibitor transfected MG63 and SaOS2 cells were placed on SA (day 6) and IA (day 9) phase of CAM development to analyze SA and IA mechanisms. It was found that miR-432-5p mimic transfection in OS promotes the transition of SA to IA which was documented by the angiogenic parameters and SA and IA-associated gene expression. Interestingly, this outcome was also supported by the zebrafish tumor xenograft model. Corroborating these results, it is clear that miR-432-5p expression in OS cells regulates SA and IA by targeting PDGFB genes. We conclude that targeting miR-432-5p/PDGFB signaling can be a potential therapeutic strategy to treat OS along with other existing strategies.

Targeting ferroptosis in osteosarcoma

Osteosarcoma (OS) is the most common primary bone tumour in children and adolescents, with high degree of malignancy and an extremely poor prognosis. Ferroptosis, a non-traditional mode of regulated cell death (RCD) characterised by iron-dependent accumulation of lipid reactive oxygen species (ROS), is closely associated with a variety of cancers. It has been demonstrated that ferroptosis can regulate OS progression and exert an essential role in the treatment of OS, which is potentially of great value. By targeting ferroptosis in OS, the present review article summarises the relevant mechanisms and therapeutic applications along with discussing current limitations and future directions, which may provide a new strategy for the treatment of OS.

microRNA-377-3p inhibits osteosarcoma progression by targeting CUL1 and regulating Wnt/β-catenin signaling pathway

OBJECTIVE

Emerging studies highlight the crucial effects of microRNAs on cancer initiation and malignant progression of various tumors. This study focused on the biological effect of miR-377-3p on CUL1 and epithelial-mesenchymal transition (EMT) and Wnt/β-catenin pathways in osteosarcoma (OS).

METHODS

We performed quantitative real-time polymerase chain reaction (qRT-PCR) to analyze miR-377-3p and CUL1 expression levels in OS tissues and MG-63 cells. Then, cell counting kit (CCK)-8 and Transwell assay were used to examine the functions of miR-377-3p in OS cell growth and metastasis abilities. Meanwhile, luciferase reporter assay was used to validate CUL1 as direct target of miR-377-3p. qRT-PCR and Western blot were then carried out to detect the impact of miR-377-3p on EMT and Wnt/β-catenin pathways. Tumor xenograft models were established to further examine the effects of miR-377-3p on OS tumorigenesis in vivo.

RESULTS

miR-377-3p downregulation was frequently identified in OS tissues and cells, which was associated with worse prognosis of OS patients. Functional experiments showed miR-377-3p restoration could dramatically repress OS cell growth and migration by regulation of EMT and Wnt/β-catenin pathways. Moreover, luciferase reporter assay revealed that CUL1 acted as a functional target of miR-377-3p. Additionally, the elevated CUL1 expressions in OS tissues also indicated poor prognosis of OS patients. Furthermore, the OS tumor growth was also obviously inhibited by miR-377-3p overexpression in vivo.

CONCLUSIONS

Collectively, all the above findings revealed that miR-377-3p exerted anti-OS functions via CUL1 and EMT and Wnt/β-catenin pathways. These results may contribute to the development of clinical OS treatment.

Combination Therapy of Cisplatin and other Agents for Osteosarcoma: A Review

Background:

Osteosarcoma is the most common type of primary bone tumor in children and adolescents, which is associated with rapid progression and poor prognosis. Multimodal therapy is the most common approach utilized for osteosarcoma management, such as the application of chemotherapy in combination with surgery or radiation therapy. Cisplatin is one of the predominantly used chemotherapeutic agents for osteosarcoma. Optimally, it is employed in combination with other chemotherapeutic drugs along with surgery or radiation therapy. Despite the availability of numerous treatment approaches, the patient survival rate has not definitively improved over the past three decades.

Methods:

We have summarized all findings regarding the combination of cisplatin with other chemotherapeutic agents as well as with phytochemical compounds.

Results:

A combination of cisplatin with a phytochemical compound synergistically enhances the killing effect of cisplatin on osteosarcoma cells with fewer side effects compared to combination with other chemotherapeutic agents.

Conclusion:

Conclusively, a combination of cisplatin with selected chemotherapeutic drugs has been shown to be effective. However, the unchanged survival rate has posed an urge to search for a new combination regimen. As a collaborative effort to substantiate the therapeutic efficacy, the combination with phytochemical compounds shows a promising response both in vitro as well as in the preclinical study.

Knockdown of MCM8 functions as a strategy to inhibit the development and progression of osteosarcoma through regulating CTGF

Osteosarcoma is the most common primary malignant tumor of bone derived from osteoblasts, which is a noteworthy threat to the health of children and adolescents. In this study, we found that MCM8 has significantly higher expression level in osteosarcoma tissues in comparison with normal tissues, which was also correlated with more advanced tumor grade and pathological stage. In agreement with the role of MCM proteins as indicators of cell proliferation, knockdown/overexpression of MCM8 inhibited/promoted osteosarcoma cell proliferation in vitro and tumor growth in vivo. Also, MCM8 knockdown/overexpression was also significantly associated with the promotion/inhibition of cell apoptosis and suppression/promotion of cell migration. More importantly, mechanistic study identified CTGF as a potential downstream target of MCM8, silencing of which could enhance the regulatory effects of MCM8 knockdown and alleviate the effects of MCM8 overexpression on osteosarcoma development. In summary, MCM8/CTGF axis was revealed as critical participant in the development and progression of osteosarcoma and MCM8 may be a promising therapeutic target for osteosarcoma treatment.

LncRNA SNHG16 promotes epithelial-mesenchymal transition by upregulating ITGA6 through miR-488 inhibition in osteosarcoma

BACKGROUND

Osteosarcoma is a primary cause of cancer-associated death in children and adolescents worldwide. Long non-coding RNAs SNHG16 (lncRNA SNHG16) and integrin subunit-a 6 (ITGA6) are recently reported to be involved in the tumorigenesis of osteosarcoma by multiple mechanisms. However, the correlation between SNHG16 and ITGA6 in osteosarcoma remains undetermined.

METHODS

Expression of miR-488, SNHG16 and ITGA6, as well as epithelial-mesenchymal transition (EMT) associated markers in osteosarcoma tissues and cell lines were examined by qRT-PCR or Western blotting. Effects of miR-488, SNHG16 and ITGA6 on cell migration, invasion were evaluated by wound-healing assay and transwell assay. Bioinformatics analysis and dual-luciferase reported assays were applied to assess the interaction among miR-488, SNHG16 and ITGA6. RNA immunoprecipitation (RIP) was also used to verify SNHG16 and miR-488 interaction. Finally, animal study was used to detect the effect of SNHG16 on osteosarcoma in vivo.

RESULTS

SNHG16 and ITGA6 were significantly increased while miR-488 was decreased in osteosarcoma. ITGA6 was screened as a target gene of miR-488, and SNHG16 was sponged by miR-488 in osteosarcoma cells. MiR-488 overexpression and SNHG16 knockdown suppressed migration, invasion and EMT of osteosarcoma cells. Moreover, rescue assays proved that the influences of SNHG16 on osteosarcoma cells migration, invasion and EMT were dependent on miR-488 and ITGA6. In addition, the promotive effects of SNHG16 on osteosarcoma tumor growth and metastasis were further supported by xenograft tumor growth assay.

CONCLUSION

SNHG16 promoted migration, invasion and EMT of osteosarcoma by sponging miR-488 to release ITGA6.

The role of Notch ligand Jagged1 in osteosarcoma proliferation, metastasis, and recurrence

BACKGROUND

Osteosarcoma is the most common primary bone cancer occurring in young adults and the 5-year survival rate of patients with metastatic osteosarcoma is less than 30% due to high metastatic recurrence and drug resistance. Notch is a highly conserved cell to cell signaling pathway in evolution, and Jagged1 is an important ligand of Notch. Although some studies have found that Notch receptors and ligands including Jagged1 were highly expressed in osteosarcoma tissues and osteosarcoma cells, the role of Jagged1 in osteosarcoma progression and metastasis are still not clear.

METHODS

Tumor tissues were collected from 68 patients and immunohistochemical staining was employed to group these patients by expression of Jagged1. Real-time quantitative PCR and Western blotting were used to detect the expression of Jagged1. We used siRNA to knockdown the expression of Jagged1 in F5M2 cells. Colony formation assay and MTT were employed to detect and analyze the proliferation of F5M2 cells with or without knockdown of Jagged1. Transwell assay were used to detect the migration and invasion of F5M2 cells.

RESULTS

In this study, we found that the high expression of Jagged1 is closely related to the metastasis and recurrence of osteosarcoma in 68 clinical specimens. The expression of Jagged1 in F5M2 cells with high metastasis was significantly higher than that in F4 cells with low metastasis. Knockdown of Jagged1 led to lower ability of proliferation, migration, and invasion in F5M2 cells.

CONCLUSION

The high expression of Jagged1 is closely related to the metastasis and recurrence of osteosarcoma. Knockdown of Jagged1 significantly reduced the proliferation, migration, and invasion of osteosarcoma cells. Our results suggested that knockdown of Jagged1 may be a potentially effective treatment for metastatic osteosarcoma.

MAFG-driven osteosarcoma cell progression is inhibited by a novel miRNA miR-4660

Osteosarcoma (OS) is the most common primary bone malignancy in the adolescent population. MAFG (v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog G) forms a heterodimer with Nrf2 (NF-E2-related factor 2), binding to antioxidant response element (ARE), which is required for Nrf2 signaling activation. We found that MAFG mRNA and protein expression is significantly elevated in human OS tissues as well as in established and primary human OS cells. In human OS cells, MAGF silencing or knockout (KO) largely inhibited OS cell growth, proliferation, and migration, simultaneously inducing oxidative injury and apoptosis activation. Conversely, ectopic overexpression of MAFG augmented OS cell progression in vitro. MicroRNA-4660 (miR-4660) directly binds the 3′ untranslated region (UTR) of MAFG mRNA in the cytoplasm of OS cells. MAFG 3′ UTR luciferase activity and expression as well as OS cell growth were largely inhibited with forced miR-4660 overexpression but augmented with miR-4660 inhibition. In vivo, MAGF short hairpin RNA (shRNA) or forced overexpression of miR-4660 inhibited subcutaneous OS xenograft growth in severe combined immunodeficient mice. Furthermore, MAFG silencing or miR-4660 overexpression inhibited OS xenograft in situ growth in proximal tibia of the nude mice. In summary, MAFG overexpression-driven OS cell progression is inhibited by miR-4660. The miR-4660-MAFG axis could be novel therapeutic target for human OS.

Cold Atmospheric Plasma: A New Strategy Based Primarily on Oxidative Stress for Osteosarcoma Therapy

Osteosarcoma is the most common primary bone tumor, and its first line of treatment presents a high failure rate. The 5-year survival for children and teenagers with osteosarcoma is 70% (if diagnosed before it has metastasized) or 20% (if spread at the time of diagnosis), stressing the need for novel therapies. Recently, cold atmospheric plasmas (ionized gases consisting of UV-Vis radiation, electromagnetic fields and a great variety of reactive species) and plasma-treated liquids have been shown to have the potential to selectively eliminate cancer cells in different tumors through an oxidative stress-dependent mechanism. In this work, we review the current state of the art in cold plasma therapy for osteosarcoma. Specifically, we emphasize the mechanisms unveiled thus far regarding the action of plasmas on osteosarcoma. Finally, we review current and potential future approaches, emphasizing the most critical challenges for the development of osteosarcoma therapies based on this emerging technique.