Osteosarcoma: a review of current and future therapeutic approaches

Sensing the future: A review on emerging technologies for assessing and monitoring bone health

Bone health is crucial at all stages of life. Several medical conditions and changes in lifestyle affect the growth, structure, and functions of bones. This may lead to the development of bone degenerative disorders, such as osteoporosis, osteoarthritis, rheumatoid arthritis, etc., which are major public health concerns worldwide. Accurate and reliable measurement and monitoring of bone health are important aspects for early diagnosis and interventions to prevent such disorders. Significant progress has recently been made in developing new sensing technologies that offer non-invasive, low-cost, and accurate measurements of bone health. In this review, we have described bone remodeling processes and common bone disorders. We have also compiled information on the bone turnover markers for their use as biomarkers in biosensing devices to monitor bone health. Second, this review details biosensing technology for bone health assessment, including the latest developments in various non-invasive techniques, including dual-energy X-ray absorptiometry, magnetic resonance imaging, computed tomography, and biosensors. Further, we have also discussed the potential of emerging technologies, such as biosensors based on nano- and micro-electromechanical systems and application of artificial intelligence in non-invasive techniques for improving bone health assessment. Finally, we have summarized the advantages and limitations of each technology and described clinical applications for detecting bone disorders and monitoring treatment outcomes. Overall, this review highlights the potential of emerging technologies for improving bone health assessment with the potential to revolutionize clinical practice and improve patient outcomes. The review highlights key challenges and future directions for biosensor research that pave the way for continued innovations to improve diagnosis, monitoring, and treatment of bone-related diseases.

MiRNA encoded PTEN's impact on clinical-pathological features and prognosis in osteosarcoma: A systematic review and meta-analysis

BACKGROUND

Osteosarcoma (OSC) is considered one of the most common malignant bone tumours in adolescents. Due to OSC's poor prognosis, a comprehensive approach to exploring these aspects is highly needed to improve the survival probability of OSC. In this study, we tried to explore the significance of miRNA-encoded PTEN for clinical-pathological features and prognostic value in OSC.

METHOD

We performed this systematic review and meta-analysis using articles and sources published between 2013 and 2023 from six databases (Scopus, PubMed, ProQuest, Science Direct, Sage Pub, and Cochrane). Included studies were clinical cross-sectional studies. Other study designs, articles not written in English, without full text, and not relevant-were excluded. Then, ROBINS-I is used to evaluate the distance. The results are constructed according to the PICOS criteria in a table. The expression of miRNA related to OSC is assessed in the meta-analysis as the main outcome to determine its ability as a diagnostic and prognostic agent for OSC. This systematic review followed the PRISMA guidelines.

RESULTS

A total of 17 studies were included in the final screening. The meta-analysis showed significantly increased (p < 0.00001) miRNA expression in patients with OSC compared to healthy controlled with pooled md (2.85) (95% CI: 2.69, 3.02; I2 = 22%, p = 0.20), the high inverse correlation (p < 0.001) between miRNA and PTEN expression was shown as mean effect size (-0.681) (95% CI: -0.787, -0.536; I2 = 75%, p < 0.0001), and the prognostic evaluation of OS was significantly increased in low expression miRNA (p < 0.00001) with pooled OR.

CONCLUSION

Fifteen miRNAs from 17 studies were found, and together with PTEN expression, they may serve as potential prognostic biomarkers for OSC. High-level levels of miRNA expression are correlated with low PTEN expression, leading to a bad prognosis for OSC.

Targeting the EphA2 pathway: could it be the way for bone sarcomas?

Bone sarcomas are malignant tumors of mesenchymal origin. Complete surgical resection is the cornerstone of multidisciplinary treatment. However, advanced, unresectable forms remain incurable. A crucial step towards addressing this challenge involves comprehending the molecular mechanisms underpinning tumor progression and metastasis, laying the groundwork for innovative precision medicine-based interventions. We previously showed that tyrosine kinase receptor Ephrin Type-A Receptor 2 (EphA2) is overexpressed in bone sarcomas. EphA2 is a key oncofetal protein implicated in metastasis, self-renewal, and chemoresistance. Molecular, genetic, biochemical, and pharmacological approaches have been developed to target EphA2 and its signaling pathway aiming to interfere with its tumor-promoting effects or as a carrier for drug delivery. This review synthesizes the main functions of EphA2 and their relevance in bone sarcomas, providing strategies devised to leverage this receptor for diagnostic and therapeutic purposes, with a focus on its applicability in the three most common bone sarcoma histotypes: osteosarcoma, chondrosarcoma, and Ewing sarcoma.

microRNA 21 and long non-coding RNAs interplays underlie cancer pathophysiology: A narrative review

Non-coding RNAs (ncRNAs) are a diverse group of functional RNA molecules that lack the ability to code for proteins. Despite missing this traditional role, ncRNAs have emerged as crucial regulators of various biological processes and have been implicated in the development and progression of many diseases, including cancer. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are two prominent classes of ncRNAs that have emerged as key players in cancer pathophysiology. In particular, miR-21 has been reported to exhibit oncogenic roles in various forms of human cancer, including prostate, breast, lung, and colorectal cancer. In this context, miR-21 overexpression is closely associated with tumor proliferation, growth, invasion, angiogenesis, and chemoresistance, whereas miR-21 inactivation is linked to the regression of most tumor-related processes. Accordingly, miR-21 is a crucial modulator of various canonical oncogenic pathways such as PTEN/PI3K/Akt, Wnt/β-catenin, STAT, p53, MMP2, and MMP9. Moreover, interplays between lncRNA and miRNA further complicate the regulatory mechanisms underlying tumor development and progression. In this regard, several lncRNAs have been found to interact with miR-21 and, by functioning as competitive endogenous RNAs (ceRNAs) or miRNA sponges, can modulate cancer tumorigenesis. This work presents and discusses recent findings highlighting the roles and pathophysiological implications of the miR-21-lncRNA regulatory axis in cancer occurrence, development, and progression. The data collected indicate that specific lncRNAs, such as MEG3, CASC2, and GAS5, are strongly associated with miR-21 in various types of cancer, including gastric, cervical, lung, and glioma. Indeed, these lncRNAs are well-known tumor suppressors and are commonly downregulated in different types of tumors. Conversely, by modulating various mechanisms and oncogenic signaling pathways, their overexpression has been linked with preventing tumor formation and development. This review highlights the significance of these regulatory pathways in cancer and their potential for use in cancer therapy as diagnostic and prognostic markers.

Prognostic and clinicopathological value of systemic immune-inflammation index in patients with osteosarcoma: a meta-analysis

Background

The efficiency of systemic immune-inflammation index (SII) in predicting prognosis of osteosarcoma (OSA) patients has been extensively analyzed, but no consistent findings are obtained. Therefore, this meta-analysis focused on identifying the precise prognostic value of SII for OSA.

Methods

We comprehensively searched electronic databases of PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure (CNKI) from inception to 24 February, 2024. Meanwhile, the efficiency of SII in predicting prognosis of OSA was evaluated by calculating pooled hazard ratios (HRs) as well as 95% confidence intervals (CIs). Additionally, the correlation of SII with the OSA clinicopathological characteristics was analyzed based on pooled odds ratios (ORs) and 95%CIs.

Results

Six studies with 1015 cases were enrolled into this work. According to the combined data, the higher SII was markedly related to poor overall survival (OS) (HR=2.01, 95%CI=1.30-3.09, p=0.002) and Enneking stage III (OR=2.21, 95%CI=1.11-4.39, p=0.024) of patients with OSA. Nonetheless, SII was not significantly related to gender, age, pathological fracture, tumor size, tumor location, tumor differentiation, and metastasis in patients with OSA.

Conclusions

In summary, the higher SII is markedly related to poor OS and advanced Enneking stage in OSA patients.

Systematic review registration

https://inplasy.com/inplasy-2024-7-0107/, identifier INPLASY202470107.

MTF2 facilitates the advancement of osteosarcoma through mediating EZH2/SFRP1/Wnt signaling

BACKGROUND

Osteosarcoma is a soft tissue neoplasm with elevated recurrence risk and highly metastatic potential. Metal response element binding transcriptional factor 2 (MTF2) has been revealed to exert multiple activities in human tissues. The present research was conducted to explore the functions and related response mechanism of MTF2 in osteosarcoma which have not been introduced yet.

METHODS

Bioinformatics tools identified the differential MTF2 expression in osteosarcoma tissues. MTF2 expression in osteosarcoma cells was examined with Western blot. Cell Counting Kit-8 (CCK-8) assay, 5-Ethynyl-2'-deoxyuridine (EDU) staining, wound healing as well as transwell assays measured cell proliferation, migration and invasion, respectively. Flow cytometry assay detected the cellular apoptotic level. Western blot also measured the expressions of proteins associated with epithelial mesenchymal transition (EMT), apoptosis and enhancer of zeste homolog 2 (EZH2)/secreted frizzled-related protein 1 (SFRP1)/Wnt signaling. Co-immunoprecipitation (Co-IP) assay confirmed MTF2-EZH2 interaction.

RESULTS

MTF2 expression was increased in osteosarcoma tissues and cells. MTF2 interference effectively inhibited the proliferation, migration and invasion of osteosarcoma cells and promoted the cellular apoptotic rate. MTF2 directly bound to EZH2 and MTF2 silence reduced EZH2 expression, activated SFRP1 expression and blocked Wnt signaling in osteosarcoma cells. EZH2 upregulation or SFRP1 antagonist WAY-316606 partly counteracted the impacts of MTF2 down-regulation on the SFRP1/Wnt signaling and the biological phenotypes of osteosarcoma cells.

CONCLUSIONS

MTF2 might down-regulate SFRP1 to activate Wnt signaling and drive the progression of osteosarcoma via interaction with EZH2 protein.

Therapeutic impacts of GNE‑477‑loaded H2O2 stimulus‑responsive dodecanoic acid‑phenylborate ester‑dextran polymeric micelles on osteosarcoma

Osteosarcoma (OS) is a highly malignant primary bone neoplasm that is the leading cause of cancer‑associated death in young people. GNE‑477 belongs to the second generation of mTOR inhibitors and possesses promising potential in the treatment of OS but dose tolerance and drug toxicity limit its development and utilization. The present study aimed to prepare a novel H2O2 stimulus‑responsive dodecanoic acid (DA)‑phenylborate ester‑dextran (DA‑B‑DEX) polymeric micelle delivery system for GNE‑477 and evaluate its efficacy. The polymer micelles were characterized by morphology, size and critical micelle concentration. The GNE‑477 loaded DA‑B‑DEX (GNE‑477@DBD) tumor‑targeting drug delivery system was established and the release of GNE‑477 was measured. The cellular uptake of GNE‑477@DBD by three OS cell lines (MG‑63, U2OS and 143B cells) was analyzed utilizing a fluorescent tracer technique. The hydroxylated DA‑B was successfully grafted onto dextran at a grafting rate of 3%, suitable for forming amphiphilic micelles. Following exposure to H2O2, the DA‑B‑DEX micelles ruptured and released the drug rapidly, leading to increased uptake of GNE‑477@DBD by cells with sustained release of GNE‑477. The in vitro experiments, including MTT assay, flow cytometry, western blotting and RT‑qPCR, demonstrated that GNE‑477@DBD inhibited tumor cell viability, arrested cell cycle in G1 phase, induced apoptosis and blocked the PI3K/Akt/mTOR cascade response. In vivo, through the observation of mice tumor growth and the results of H&E staining, the GNE‑477@DBD group exhibited more positive therapeutic outcomes than the free drug group with almost no adverse effects on other organs. In conclusion, H2O2‑responsive DA‑B‑DEX presents a promising delivery system for hydrophobic anti‑tumor drugs for OS therapy.

Exploring the molecular landscape of osteosarcoma through PTTG family genes using a detailed multi-level methodology

Background

Osteosarcoma (OS) poses a significant clinical challenge, necessitating a comprehensive exploration of its molecular underpinnings.

Methods

This study explored the roles of PTTG family genes (PTTG1, PTTG2, and PTTG3P) in OS, employing a multifaceted approach encompassing molecular experiments, including OS cell lines culturing, RT-qPCR, bisulfite and Whole Exome Sequencing (WES) and in silico experiments, including The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets-based validation, overall survival, gene enrichment, functional assays, and molecular docking analyses.

Results

Our findings reveal a consistent up-regulation of PTTG genes in OS cell lines, supported by RT-qPCR experiments and corroborated across various publically available expression datasets databases. Importantly, ROC curve analyses highlight their potential as diagnostic markers. Moving beyond expression profiles, we unveil the epigenetic landscape by demonstrating significant hypomethylation of CpG islands associated with PTTG genes in OS. The negative correlation between methylation status and mRNA expression emphasizes the regulatory role of promoter methylation in PTTG gene expression. Contrary to expectations, genetic mutations in PTTG genes are rare in OS, with only benign mutations observed. Moreover, functional assays also confirmed the oncogenic roles of the PTTG gene in the development of OS. Lastly, we also revealed that Calcitriol is the most appropriate drug that can be utilized to treat OS in the context of PTTG genes.

Conclusion

The identification of PTTG genes as potential diagnostic markers and their association with epigenetic alterations opens new avenues for understanding OS pathogenesis and developing targeted therapies. As we navigate the complex landscape of OS, this study contributes essential insights that may pave the way for improved diagnostic and therapeutic strategies in its management.

Combined use of niraparib enhanced the inhibitory effect of Anti-GD2 antibody on osteosarcoma cells

PURPOSE

This study aims to investigate the effect of Niraparib in combination with an Anti-GD2 Antibody on osteosarcoma cells.

METHODS

Scratch test was utilized to assess cell migration capacity, while the Transwell experiment was utilized to evaluate cell invasion potential. Cell proliferation was measured using the CCK8 experiment. The affinity between the anti-GD2 antibody and its antigen was determined via ELISA. Tumor growth was evaluated through animal experiments. Western blotting, QRT-PCR, and histological analysis were conducted to examine the expression of relevant proteins and mRNAs.

RESULTS

MG63 cell line was used for an example. The scratch test showed that the migration rate of osteosarcoma cells in Niraparib + Anti-GD2 group was 1.07 ± 0.04 after 48 h, and 0.34 ± 0.04 in the Control group. Transwell experiment showed that the invasion ability of osteosarcoma cells in Niraparib + Anti-GD2 group was 21.0 ± 1.5, and that in Control group was 87.7 ± 2.9. CCK8 experiment showed that the absorbance value of Niraparib + Anti-GD2 group was 0.16 ± 0.10 on day 5, and that of the Control group was 0.76 ± 0.09. Western blotting showed that the expression levels of BALP and CICP in Niraparib + Anti-GD2 group were 0.751 ± 0.135 and 1.086 ± 0.115, respectively, and those in Control group were 1.025 ± 0.143 and 1.216 ± 0.168, respectively. QRT-PCR results showed that the absorbance values of Niraparib + Anti-GD2 group were 0.173 ± 0.065 and 0.170 ± 0.078 on day 14. The results of animal experiments showed that on day 5, the tumor volume of the Control group was 2433 ± 391, and that of the Niraparib + Anti-GD2 group was 1137 ± 148. Histological analysis showed that the mean density values of Niraparib + Anti-GD2 group were 0.19 ± 0.08 and 0.22 ± 0.07, and those of Control group were 0.26 ± 0.09 and 0.29 ± 0.10.

CONCLUSION

The combination of Niraparib and Anti-GD2 antibody significantly inhibits Osteosarcoma cells.

MFAP2 induces epithelial-mesenchymal transformation of osteosarcoma cells by activating the Notch1 pathway

Background

Osteosarcoma (OS) is a malignancy originating from mesenchymal tissue. Microfibril-associated protein 2 (MFAP2) plays a crucial role in cancer, notably promoting epithelial-mesenchymal transition (EMT). However, its involvement in OS remains unexplored.

Methods

MFAP2 was silenced in U2OS cells using shRNA targeting MFAP2 (sh-MFAP2) and validated by quantitative real-time polymerase chain reaction (qRT-PCR). We extracted gene chip data of MFAP2 from multiple databases (GSE28424, GSE42572, and GSE126209). Correlation analyses between MFAP2 and the Notch1 pathway identified through the gene set variation analysis (GSVA) enrichment analysis were conducted using the Pearson correlation method. Cellular behaviors (viability, migration, and invasion) were assessed via the Cell Counting Kit-8 (CCK-8), wound healing, and Transwell assays. EMT markers (N-cadherin, vimentin, and β-catenin) and Notch1 levels were examined by western blotting and qRT-PCR. Cell morphology was observed microscopically to evaluate EMT. Finally, the role of MFAP2 in OS was validated through a xenograft tumor model.

Results

OS cell lines exhibited higher MFAP2 mRNA expression than normal osteoblasts. MFAP2 knockdown in U2OS cells significantly reduced viability, migration, and invasion, along with downregulation of N-cadherin and vimentin, as well as upregulation of β-catenin. MFAP2 significantly correlated with the Notch1 pathway in OS and its knockdown inhibited Notch1 protein expression. Furthermore, Notch1 activation reversed the inhibitory effects of MFAP2 knockdown on the malignant characteristic of U2OS cells. Additionally, MFAP2 knockdown inhibited tumor growth, expression levels of EMT markers, and Notch1 expression in OS tumor tissues.

Conclusions

Our study revealed that MFAP2 was an upstream regulator of the Notch1 signaling pathway to promote EMT in OS. These findings suggested MFAP2 as a potential OS therapy target.

Inhibiting Bruton's Tyrosine Kinase to Counteract Chemoresistance and Stem Cell-Like Properties in Osteosarcoma

Osteosarcoma, a highly aggressive bone cancer, often develops resistance to conventional chemotherapeutics, leading to poor prognosis and survival rates. The malignancy and chemoresistance of osteosarcoma pose significant challenges in its treatment, highlighting the critical need for novel therapeutic approaches. Bruton's tyrosine kinase (BTK) plays a pivotal role in B-cell development and has been linked to various cancers, including breast, lung, and oral cancers, where it contributes to tumor growth and chemoresistance. Despite its established importance in these malignancies, the impact of BTK on osteosarcoma remains unexplored. Our study delves into the expression levels of BTK in osteosarcoma tissues by data from the GEO and TCGA database, revealing a marked increase in BTK expression compared with primary osteoblasts and a potential correlation with primary site progression. Through our investigations, we identified a subset of osteosarcoma cells, named cis-HOS, which exhibited resistance to cisplatin. These cells displayed characteristics of cancer stem cells (CSCs), demonstrated a higher angiogenesis effect, and had an increased migration ability. Notably, an upregulation of BTK was observed in these cisplatin-resistant cells. The application of ibrutinib, a BTK inhibitor, significantly mitigated these aggressive traits. Our study demonstrates that BTK plays a crucial role in conferring chemoresistance in osteosarcoma. The upregulation of BTK in cisplatin-resistant cells was effectively countered by ibrutinib. These findings underscore the potential of targeting BTK as an effective strategy to overcome chemoresistance in osteosarcoma treatment.

Multi-omic validation of the cuproptosis-sphingolipid metabolism network: modulating the immune landscape in osteosarcoma

Background

The current understanding of the mechanisms by which metal ion metabolism promotes the progression and drug resistance of osteosarcoma remains incomplete. This study aims to elucidate the key roles and mechanisms of genes involved in cuproptosis-related sphingolipid metabolism (cuproptosis-SPGs) in regulating the immune landscape, tumor metastasis, and drug resistance in osteosarcoma cells.

Methods

This study employed multi-omics approaches to assess the impact of cuproptosis-SPGs on the prognosis of osteosarcoma patients. Lasso regression analysis was utilized to construct a prognostic model, while multivariate regression analysis was applied to identify key core genes and generate risk coefficients for these genes, thereby calculating a risk score for each osteosarcoma patient. Patients were then stratified into high-risk and low-risk groups based on their risk scores. The ESTIMATE and CIBERSORT algorithms were used to analyze the level of immune cell infiltration within these risk groups to construct the immune landscape. Single-cell analysis was conducted to provide a more precise depiction of the expression patterns of cuproptosis-SPGs among immune cell subtypes. Finally, experiments on osteosarcoma cells were performed to validate the role of the cuproptosis-sphingolipid signaling network in regulating cell migration and apoptosis.

Results

In this study, seven cuproptosis-SPGs were identified and used to construct a prognostic model for osteosarcoma patients. In addition to predicting survival, the model also demonstrated reliability in forecasting the response to chemotherapy drugs. The results showed that a high cuproptosis-sphingolipid metabolism score was closely associated with reduced CD8 T cell infiltration and indicated poor prognosis in osteosarcoma patients. Cellular functional assays revealed that cuproptosis-SPGs regulated the LC3B/ERK signaling pathway, thereby triggering cell death and impairing migration capabilities in osteosarcoma cells.

Conclusion

The impact of cuproptosis-related sphingolipid metabolism on the survival and migration of osteosarcoma cells, as well as on CD8 T cell infiltration, highlights the potential of targeting copper ion metabolism as a promising strategy for osteosarcoma patients.

PSMD14 is a novel prognostic marker and therapeutic target in osteosarcoma

BACKGROUND

Osteosarcoma is a bone tumor that is characterized by high malignancy and a high mortality rate, and that originates from primitive osteoblastic mesenchymal cells and is most common in rapidly growing long bones. PSMD14, also known as RPN11 or POH1, is a member of the JAMM isopeptidase family, which is able to remove the substrate protein ubiquitination label, thereby regulating the stability and function of the substrate protein. In this study, we explored the expression and potential biological significance of the PSMD14 deubiquitinating enzyme in osteosarcoma.

METHODS

Immunohistochemical methods were used to detect the expression of PSMD14 in biopsies of 91 osteosarcoma patients, and the specimens were classified into high and low PSMD14 expression groups. The correlation between PSMD14 expression and clinical indicators and prognosis was compared.SiRNA was used to downregulate PSMD14 in two osteosarcoma cell lines (HOS and SJSA-1), and the effects of downregulation of PSMD14 on the viability, proliferation, and invasion ability of osteosarcoma cells were analyzed.

RESULTS

We identified significant differences in recurrence, metastasis, and survival time of the osteosarcoma patients on the basis of PSMD14 expression. High expression of PSMD14 in osteosarcoma patients was associated with a low survival rate and high risk of metastasis and recurrence. Down-regulation of PSMD14 inhibited the viability, proliferation, and invasiveness of osteosarcoma cell lines.

CONCLUSIONS

PSMD14 may be a new prognostic marker and therapeutic target for osteosarcoma.

Ferroptosis defense mechanisms: The future and hope for treating osteosarcoma

Currently, challenges such as chemotherapy resistance, resulting from preoperative and postoperative chemotherapy, postoperative recurrence, and poor bone regeneration quality, are becoming increasingly prominent in osteosarcoma (OS) treatment. There is an urgent need to find more effective ways to address these issues. Ferroptosis is a novel form of iron-dependent programmed cell death, distinct from other forms of cell death. In this paper, we summarize how, through the three major defense systems of ferroptosis, not only can substances from traditional Chinese medicine, antitumor drugs, and nano-drug carriers induce ferroptosis in OS cells, but they can also be combined with immunotherapy, differentiation therapy, and other treatment modalities to significantly enhance chemotherapy sensitivity and inhibit tumor growth. Thus, ferroptosis holds great potential in treating OS, offering more choices and possibilities for future clinical interventions.

Targeting nicotinamide N-methyltransferase decreased aggressiveness of osteosarcoma cells

BACKGROUND

Osteosarcoma (OS) is a primary bone malignancy that mostly affects young people, characterized by high metastatic potential, and a marked chemoresistance that is responsible for disease relapse in most patients. Therefore, it is necessary to identify novel molecules to setup targeted strategies to improve the clinical outcome. The enzyme nicotinamide N-methyltransferase (NNMT) catalyses the N-methylation of nicotinamide and other analogs, playing a crucial role in the biotransformation of drugs and xenobiotics. NNMT overexpression was reported in a wide variety of cancers, and several studies demonstrated that is able to promote cell proliferation, migration and resistance to chemotherapy. The aim of this study was to explore the potential involvement of NNMT in OS.

METHODS

Immunohistochemical analyses have been performed to evaluate NNMT expression in selected OS and healthy bone tissue samples. Subsequently, OS cell lines have been transfected with vectors targeting NNMT mRNA (shRNAs) and the impact of this downregulation on migration, cell proliferation, and response to chemotherapeutic treatment was also analysed by wound healing, MTT, SRB and Trypan blue assays, respectively.

RESULTS

Results showed that OS samples display a significantly higher NNMT expression compared with healthy tissue. Preliminary results suggest that NNMT silencing in OS cell lines is associated to a decrease of cell proliferation and migration, as well as to enhanced sensitivity to chemotherapy. Data obtained showed that NNMT may represent an interesting marker for OS detection and a promising target for effective anti-cancer therapy.

CB65 and novel CB65 liposomal system suppress MG63 and Saos-2 osteosarcoma cell growth in vitro

Curable approaches for primary osteosarcoma are inadequate and urge investigation of novel therapeutic formulations. Cannabinoid ligands exert antiproliferative and apoptotic effect on osteosarcoma cells via cannabinoid 2 (CB2) or transient receptor potential vanilloid type (TRPV1) receptors. In this study, we confirmed CB2 receptor expression in MG63 and Saos-2 osteosarcoma cells by qRT-PCR and flow cytometry (FCM), then reported the reduction effect of synthetic specific CB2 receptor agonist CB65 on the proliferation of osteosarcoma cells by WST-1 (water-soluble tetrazolium-1) and RTCA (real-time impedance-based proliferation). CB65 revealed an IC50 (inhibitory concentration) for MG63 and Saos-2 cells as 1.11 × 10-11 and 4.95 × 10-11 M, respectively. The specific antiproliferative effect of CB65 on osteosarcoma cells was inhibited by CB2 antagonist AM630. CB65 induced late apoptosis of MG63 and Saos-2 cells at 24 and 48 h, respectively by FCM when applied submaximal concentration. A novel CB65 liposomal system was generated by a thin film hydration method with optimal particle size (141.7 ± 0.6 nm), polydispersity index (0.451 ± 0.026), and zeta potential (-10.9 ± 0.3 mV) values. The encapsulation efficiency (EE%) of the CB65-loaded liposomal formulation was 51.12%. The CB65 and CB65-loaded liposomal formulation releasing IC50 of CB65 reduced proliferation by RTCA and invasion by scratch assay and induced late apoptosis of MG63 and Saos-2 cells, by FCM. Our results demonstrate the CB2 receptor-mediated antiproliferative and apoptotic effect of a new liposomal CB65 delivery system on osteosarcoma cells that can be used as a targeted and intelligent tool for bone tumors to ameliorate pediatric bone cancers following in vivo validation.

Correlation of High-Grade Osteosarcoma Response to Chemotherapy with Enhanced Tissue Immunological Response: Analysis of CD95R, IFN-γ, Catalase, Hsp70, and VEGF

High-grade osteosarcoma, a primary malignant bone tumour, is experiencing a global increase in reported incidence with varied prevalence. Despite advances in management, which include surgery and neoadjuvant chemotherapy often an unsatisfactory outcome is found due to poor or heterogeneous response to chemotherapy. Our study delved into chemotherapy responses in osteosarcoma patients and associated molecular expressions, focusing on CD95 receptor (CD95R), interferon (IFN)-γ, catalase, heat-shock protein (Hsp)70, and vascular endothelial growth factor (VEGF). Employing immunohistochemistry and Huvos grading of post-chemo specimens, we analysed formalin-fixed paraffin-embedded (FFPE) osteosarcoma tissue of resected post-chemotherapy specimens from Dr. Soetomo General Academic Hospital in Surabaya, Indonesia (DSGAH), spanning from 2016 to 2020. Results revealed varied responses (poor 40.38%, moderate 48.08%, good 11.54%) and distinct patterns in CD95R, IFN-γ, catalase, Hsp70, and VEGF expression. Significant differences among response groups were observed in CD95R and IFN-γ expression in tumour-infiltrating lymphocytes. The trend of diminishing CD95R expression from poor to good responses, accompanied by an increase in IFN-γ, implied a reduction in the count of viable osteosarcoma cells with the progression of Huvos grading. Catalase expression in osteosarcoma cells was consistently elevated in the poor response group, while Hsp70 expression was highest. VEGF expression in macrophages was significantly higher in the good response group. In conclusion, this study enhances our understanding of immune-chemotherapy interactions in osteosarcoma and identifies potential biomarkers for targeted interventions.

TCF12 Transcriptionally Activates SPHK1 to Induce Osteosarcoma Angiogenesis by Promoting the S1P/S1PR4/STAT3 Axis

Transcription factor 12 (TCF12) is a known oncogene in many cancers. However, whether TCF12 can regulate malignant phenotypes and angiogenesis in osteosarcoma is not elucidated. In this study, we demonstrated increased expression of TCF12 in osteosarcoma tissues and cell lines. High TCF12 expression was associated with metastasis and poor survival rate of osteosarcoma patients. Knockdown of TCF12 reduced the proliferation, migration, and invasion of osteosarcoma cells. TCF12 was found to bind to the promoter region of sphingosine kinase 1 (SPHK1) to induce transcriptional activation of SPHK1 expression and enhance the secretion of sphingosine-1-phosphate (S1P), which eventually resulted in the malignant phenotypes of osteosarcoma cells. In addition, S1P secreted by osteosarcoma cells promoted the angiogenesis of HUVECs by targeting S1PR4 on the cell membrane to activate the STAT3 signaling pathway. These findings suggest that TCF12 may induce transcriptional activation of SPHK1 to promote the synthesis and secretion of S1P. This process likely enhances the malignant phenotypes of osteosarcoma cells and induces angiogenesis via the S1PR4/STAT3 signaling pathway.

USP22 as a key regulator of glycolysis pathway in osteosarcoma: insights from bioinformatics and experimental approaches

Background

Osteosarcoma is the most common primary malignant bone tumor, but its pathogenesis remains unclear. Ubiquitin-specific processing peptidase 22 (USP22) is reported to be highly expressed and associated with tumor malignancy and prognosis in cancers. However, the role and mechanism of USP22 in osteosarcoma is not fully understood. This study aims to investigate the function and potential mechanism of USP22 in osteosarcoma using bioinformatics analysis combined with experimental validation.

Methods

We first integrated transcriptomic datasets and clinical information of osteosarcoma from GEO and TCGA databases to assess the expression and prognostic value of USP22 in osteosarcoma. Then, differential expression analysis and weighted gene co-expression network analysis (WGCNA) were conducted to identify USP22-related co-expressed genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to explore the biological functions and signaling pathways of USP22 co-expressed genes. To validate the accuracy of bioinformatics analyses, we downregulated USP22 expression in osteosarcoma cell line Sao-2 using siRNA and assessed its effect on cell proliferation, migration, invasion, apoptosis, and regulation of key signaling pathways.

Results

We found that USP22 was highly expressed in osteosarcoma tissues and correlated with poor prognosis in osteosarcoma patients. USP22 also showed potential as a diagnostic marker for osteosarcoma. In addition, 344 USP22-related co-expressed genes were identified, mainly involved in signaling pathways such as glycolysis, oxidative phosphorylation, spliceosome, thermogenesis, and cell cycle. The in vitro experiments confirmed the accuracy and reliability of bioinformatics analyses. We found that downregulation of USP22 could inhibit Sao-2 cell proliferation, migration, invasion, and induce apoptosis. Furthermore, downregulation of USP22 significantly reduced aerobic glycolysis levels in Sao-2 cells and inhibited the expression of key enzymes and transporters in aerobic glycolysis pathways such as HK2, PKM2, and GLUT1.

Conclusions

USP22 plays a critical role in the occurrence, development, and prognosis of osteosarcoma. USP22 could influence Sao-2 cell proliferation, apoptosis, migration, and invasion by regulating the glycolysis pathway, thereby promoting osteosarcoma progression. Therefore, USP22 may be a potential therapeutic target for the treatment of osteosarcoma.

The Biological Impact of Some Phosphonic and Phosphinic Acid Derivatives on Human Osteosarcoma

Osteosarcoma malignancy currently represents a major health problem; therefore, the need for new therapy approaches is of great interest. In this regard, the current study aims to evaluate the anti-neoplastic potential of a newly developed phosphinic acid derivative (2-carboxyethylphenylphosphinic acid) and, subsequently, to outline its pharmaco-toxicological profile by employing two different in vitro human cell cultures (keratinocytes-HaCaT-and osteosarcoma SAOS-2 cells), employing different techniques (MTT assay, cell morphology assessment, LDH assay, Hoechst staining and RT-PCR). Additionally, the results obtained are compared with three commercially available phosphorus-containing compounds (P1, P2, P3). The results recorded for the newly developed compound (P4) revealed good biocompatibility (cell viability of 77%) when concentrations up to 5 mM were used on HaCaT cells for 24 h. Also, the HaCaT cultures showed no significant morphological alterations or gene modulation, thus achieving a biosafety profile even superior to some of the commercial products tested herein. Moreover, in terms of anti-osteosarcoma activity, 2-carboxyethylphenylphosphinic acid expressed promising activity on SAOS-2 monolayers, the cells showing viability of only 55%, as well as apoptosis features and important gene expression modulation, especially Bid downregulation. Therefore, the newly developed compound should be considered a promising candidate for further in vitro and in vivo research related to osteosarcoma therapy.

A Specific, Measurable, Achievable, Relevant, Timed (SMART) Nursing Project Reduces Anxiety, Depression, and Post-Traumatic Stress Disorder in Parents of Childhood or Adolescent Osteosarcoma Patients

Specific, measurable, achievable, relevant, timed (SMART) principle improves the nursing utility by setting individual goals for participants and helping them to achieve these goals. Our study intended to investigate the impact of a SMART nursing project on reducing mental stress and post-traumatic stress disorder (PTSD) in parents of childhood or adolescent osteosarcoma patients. In this randomized, controlled study, 66 childhood or adolescent osteosarcoma patients and 126 corresponding parents were enrolled and divided into SMART or normal care (NC) groups at a 1:1 ratio. All parents received a 3-month corresponding intervention and a 6-month interview. Our study revealed that the self-rating anxiety scale score at the 3rd month (M3) (P < 0.05) and the 6th month (M6) (P < 0.01), and anxiety rate at M3 (P < 0.05) and M6 (P < 0.05) were lower in parents in SMART group vs. NC group. The self-rating depression scale score at M3 and M6, and depression rate at M3 and M6 were lower in parents in SMART group vs. NC group (all P < 0.05). Impact of events scale-revised score at the 1st month (M1) (P < 0.05), M3 (P < 0.05), and M6 (P < 0.01) were lower in parents in SMART group vs. NC group. By subgroup analyses, the SMART nursing project showed better impacts on decreasing anxiety, depression, and PTSD in parents with an undergraduate education or above than in those with a high school education or less. Conclusively, SMART nursing project reduces anxiety, depression, and PTSD in parents of childhood or adolescent osteosarcoma patients, which is more effective in those with higher education.

Lipid Peroxidation-Related Redox Signaling in Osteosarcoma

Oxidative stress and lipid peroxidation play important roles in numerous physiological and pathological processes, while the bioactive products of lipid peroxidation, lipid hydroperoxides and reactive aldehydes, act as important mediators of redox signaling in normal and malignant cells. Many types of cancer, including osteosarcoma, express altered redox signaling pathways. Such redox signaling pathways protect cancer cells from the cytotoxic effects of oxidative stress, thus supporting malignant transformation, and eventually from cytotoxic anticancer therapies associated with oxidative stress. In this review, we aim to explore the status of lipid peroxidation in osteosarcoma and highlight the involvement of lipid peroxidation products in redox signaling pathways, including the involvement of lipid peroxidation in osteosarcoma therapies.

Role of proteoglycan synthesis genes in osteosarcoma stem cells

Osteosarcoma stem cells (OSCs) contribute to the pathogenesis of osteosarcoma (OS), which is the most common malignant primary bone tumor. The significance and underlying mechanisms of action of proteoglycans (PGs) and glycosaminoglycans (GAGs) in OSC phenotypes and OS malignancy are largely unknown. This study aimed to investigate the role of PG/GAG biosynthesis and the corresponding candidate genes in OSCs and poor clinical outcomes in OS using scRNA-seq and bulk RNA-seq datasets of clinical OS specimens, accompanied by biological validation by in vitro genetic and pharmacological analyses. The expression of β-1,3-glucuronyltransferase 3 (B3GAT3), one of the genes responsible for the biosynthesis of the common core tetrasaccharide linker region of PGs, was significantly upregulated in both OSC populations and OS tissues and was associated with poor survival in patients with OS with high stem cell properties. Moreover, the genetic inactivation of B3GAT3 by RNA interference and pharmacological inhibition of PG biosynthesis abrogated the self-renewal potential of OSCs. Collectively, these findings suggest a pivotal role for B3GAT3 and PG/GAG biosynthesis in the regulation of OSC phenotypes and OS malignancy, thereby providing a potential target for OSC-directed therapy.

Development and validation of a pyroptosis-related prognostic signature associated with osteosarcoma metastasis and immune infiltration

Pyroptosis is a programmed cell death, which has garnered increasing attention because it relates to the immune and therapy response. However, few studies focus on the application of pyroptosis-related genes (PRGs) in predicting osteosarcoma (OS) patients' prognoses. In this study, the gene expression and clinical information of OS patients were downloaded from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. Based on these PRGs and unsupervised clustering analysis, all OS samples can be classified into 2 clusters. The 8 key differential expressions for PRGs (LAG3, ITGAM, CCL2, TLR4, IL2RA, PTPRC, FCGR2B, and CD5) were established through the univariate Cox regression and utilized to calculate the risk score of all samples. According to the 8-gene signature, OS samples can be divided into high and low-risk groups and correlation analysis can be performed using immune cell infiltration and immune checkpoints. Finally, we developed a nomogram to improve the PRG-predictive model in clinical application. We verified the predictive performance using receiver operating characteristic (ROC) and calibration curves. There were significant differences in survival, immune cell infiltration and immune checkpoints between the low and high-risk groups. A nomogram was developed with clinical indicators and the risk scores were effective in predicting the prognosis of patients with OS. In this study, a prognostic model was constructed based on 8 PRGs were proved to be independent prognostic factors of OS and associated with tumor immune microenvironment. These 8 prognostic genes were involved in OS development and may serve as new targets for developing therapeutic drugs.

Repurposing the diuretic benzamil as an anti-osteosarcoma agent that acts by suppressing integrin/FAK/STAT3 signalling and compromising mitochondrial function

Aims

Osteosarcoma is the most common primary bone malignancy among children and adolescents. We investigated whether benzamil, an amiloride analogue and sodium-calcium exchange blocker, may exhibit therapeutic potential for osteosarcoma in vitro.

Methods

MG63 and U2OS cells were treated with benzamil for 24 hours. Cell viability was evaluated with the MTS/PMS assay, colony formation assay, and flow cytometry (forward/side scatter). Chromosome condensation, the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay, cleavage of poly-ADP ribose polymerase (PARP) and caspase-7, and FITC annexin V/PI double staining were monitored as indicators of apoptosis. Intracellular calcium was detected by flow cytometry with Fluo-4 AM. The phosphorylation and activation of focal adhesion kinase (FAK) and signal transducer and activator of transcription 3 (STAT3) were measured by western blot. The expression levels of X-linked inhibitor of apoptosis protein (XIAP), B-cell lymphoma 2 (Bcl-2), B-cell lymphoma-extra large (Bcl-xL), SOD1, and SOD2 were also assessed by western blot. Mitochondrial status was assessed with tetramethylrhodamine, ethyl ester (TMRE), and intracellular adenosine triphosphate (ATP) was measured with BioTracker ATP-Red Live Cell Dye. Total cellular integrin levels were evaluated by western blot, and the expression of cell surface integrins was assessed using fluorescent-labelled antibodies and flow cytometry.

Results

Benzamil suppressed growth of osteosarcoma cells by inducing apoptosis. Benzamil reduced the expression of cell surface integrins α5, αV, and β1 in MG63 cells, while it only reduced the expression of αV in U2OS cells. Benzamil suppressed the phosphorylation and activation of FAK and STAT3. In addition, mitochondrial function and ATP production were compromised by benzamil. The levels of anti-apoptotic proteins XIAP, Bcl-2, and Bcl-xL were reduced by benzamil. Correspondingly, benzamil potentiated cisplatin- and methotrexate-induced apoptosis in osteosarcoma cells.

Conclusion

Benzamil exerts anti-osteosarcoma activity by inducing apoptosis. In terms of mechanism, benzamil appears to inhibit integrin/FAK/STAT3 signalling, which triggers mitochondrial dysfunction and ATP depletion.

BMS-794833 reduces anlotinib resistance in osteosarcoma by targeting the VEGFR/Ras/CDK2 pathway

Background

Osteosarcoma, a tumor that originates from bone cells, has a poor prognosis and a high degree of malignancy. Anlotinib, a small-molecule multi-target tyrosine kinase inhibitor (TKI), is the first-line drug in treating osteosarcoma, especially in late-stage osteosarcoma. However, patients often develop resistance after using anlotinib for a certain period, which poses a challenge to its further clinical application. Recently, several TKIs, for instance regorafenib and cabozantinib, have showed clinical interest in treating osteosarcoma and target both vascular endothelial growth factor receptor (VEGFR) and mesenchymal epithelial transition factor (c-MET). Therefore, the identification of new TKI warrants further investigation.

Methods

We performed CCK8 aasays to confirm that BMS-794833 sensitization osteosarcoma cells to anlotinib. Bioinformatics analysis and rescue experiments showed that the reduce of resistance were dependent on the VEGFR/Ras/CDK2 pathway. Cell line based xenograft model were used to demonstrate that BMS-794833 and anlotinib could synergistically treat OS.

Results

Here, we found that BMS-794833 reduced anlotinib resistance in osteosarcoma by targeting the VEGFR/Ras/CDK2 pathway. CCK8 assay showed that BMS-794833 significantly improved the resistance of osteosarcoma cells to anlotinib. The results of rescue experiments showed that the regulatory effects of BMS-794833 on the proliferation and drug resistance of osteosarcoma cells were dependent on the VEGFR/Ras/CDK2 pathway. In addition, BMS-794833 affected the resistance of osteosarcoma cells to anlotinib through epithelial-mesenchymal transition (EMT) and apoptosis pathways. More importantly, BMS-794833 and anlotinib exerted synergistic therapeutic effects against osteosarcoma in vivo.

Conclusion

Altogether, this study reveals a new (VEGFR)-targeting drug that can be combined with anlotinib for the treatment of osteosarcoma, which provides an important theoretical basis for overcoming anlotinib resistance.

The Oncolytic Effect of Aerva lanata on Osteosarcoma Cell Lines via the Apoptotic Signaling Pathway

Introduction Osteosarcoma, a malignant bone tumor, poses significant treatment challenges, necessitating the development of alternative therapeutic strategies. Aerva lanata (A. lanata), a medicinal plant with traditional use in various healthcare systems, has anti-cancer properties. This study looks at the oncolytic effect of A. lanata extract on osteosarcoma cell lines (sarcoma osteogenic-Saos2). Aim The aim of this study was to investigate the oncolytic effect of Aerva lanata on Saos2 cell lines through the apoptotic signaling pathway. Materials and methods A. lanata extract was prepared using Soxhlet extraction, and its cytotoxic effects on Saos2 cells were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Real-time polymerase chain reaction (RT-PCR) analysis of gene activity was used to assess the extract's effect on apoptotic signaling pathways. Results The MTT assay demonstrated a dose-dependent decrease in Saos2 proliferation following treatment with A. lanata extract at concentrations ranging from 50 μg to 200 μg. The standard deviations observed ranged from 1.414 to 7.071. Gene expression analysis revealed that the extract led to a reduction in the messenger ribonucleic acid (mRNA) levels of the anti-apoptotic marker B-cell lymphoma 2 (Bcl2), with standard deviations ranging from 1 to 0.535. Conversely, it induced an increase in the mRNA levels of the tumor suppressor protein p53, with standard deviations ranging from 1 to 1.835. These findings suggest that the extract modulates the apoptotic pathways of the Bcl2 and p53 genes.  Conclusion A. lanata extract exhibits promising anti-cancer activity against Saos2 osteosarcoma cell lines, inducing apoptosis by downregulating Bcl2 and increasing p53. The study's findings suggest that A. lanata may be useful as a natural treatment for osteosarcoma.

miR-1246 promotes osteosarcoma cell migration via NamiRNA-enhancer network dependent on Argonaute 2

High metastatic propensity of osteosarcoma leads to its therapeutic failure and poor prognosis. Although nuclear activation miRNAs (NamiRNAs) are reported to activate gene transcription via targeting enhancer and further promote tumor metastasis, it remains uncertain whether NamiRNAs regulate osteosarcoma metastasis and their exact mechanism. Here, we found that extracellular vesicles of the malignant osteosarcoma cells (143B) remarkably increased the migratory abilities of MNNG cells representing the benign osteosarcoma cells by two folds, which attributed to their high miR-1246 levels. Specially, miR-1246 located in nucleus could activate the migration gene expression (such as MMP1) to accelerate MNNG cell migration through elevating the enhancer activities via increasing H3K27ac enrichment. Instead, MMP1 expression was dramatically inhibited after Argonaute 2 (AGO2) knockdown. Notably, in vitro assays demonstrated that AGO2 recognized the hybrids of miR-1246 and its enhancer DNA via PAZ domains to prevent their degradation from RNase H and these protective roles of AGO2 may favor the gene activation by miR-1246 in vivo. Collectively, our findings suggest that miR-1246 could facilitate osteosarcoma metastasis through interacting with enhancer to activate gene expression dependent on AGO2, highlighting the nuclear AGO2 as a guardian for NamiRNA-targeted gene activation and the potential of miR-1246 for osteosarcoma metastasis therapy.

Biomechanical Aspects in Bone Tumor Engineering

In the past decades, anticancer drug development brought the field of tumor engineering to a new level by the need of robust test systems. Simulating tumor microenvironment in vitro remains a challenge, and osteosarcoma-the most common primary bone cancer-is no exception. The growing evidence points to the inevitable connection between biomechanical stimuli and tumor chemosensitivity and aggressiveness, thus making this component of the microenvironment a mandatory requirement to the developed models. In this review, we addressed the question: is the "in vivo - in vitro" gap in osteosarcoma engineering bridged from the perspective of biomechanical stimuli? The most notable biomechanical cues in the tumor cell microenvironment are observed and compared in the contexts of in vivo conditions and engineered three-dimensional in vitro models. Impact statement The importance of biomechanical stimuli in three-dimensional in vitro models for drug testing is becoming more pronounced nowadays. This review might assist in understanding the key players of the biophysical environment of primary bone cancer and the current state of bone tumor engineering from this perspective.

Codelivery of anti-CD47 antibody and chlorin e6 using a dual pH-sensitive nanodrug for photodynamic immunotherapy of osteosarcoma

Osteosarcoma is a malignant tumor originating from bone tissue that progresses rapidly and has a poor patient prognosis. Immunotherapy has shown great potential in the treatment of osteosarcoma. However, the immunosuppressive microenvironment severely limits the efficacy of osteosarcoma treatment. The dual pH-sensitive nanocarrier has emerged as an effective antitumor drug delivery system that can selectively release drugs into the acidic tumor microenvironment. Here, we prepared a dual pH-sensitive nanocarrier, loaded with the photosensitizer Chlorin e6 (Ce6) and CD47 monoclonal antibodies (aCD47), to deliver synergistic photodynamic and immunotherapy of osteosarcoma. On laser irradiation, Ce6 can generate reactive oxygen species (ROS) to kill cancer cells directly and induces immunogenic tumor cell death (ICD), which further facilitates the dendritic cell maturation induced by blockade of CD47 by aCD47. Moreover, both calreticulin released during ICD and CD47 blockade can accelerate phagocytosis of tumor cells by macrophages, promote antigen presentation, and eventually induce T lymphocyte-mediated antitumor immunity. Overall, the dual pH-sensitive nanodrug loaded with Ce6 and aCD47 showed excellent immune-activating and anti-tumor effects in osteosarcoma, which may lay the theoretical foundation for a novel combination model of osteosarcoma treatment.

Mitochondria targeted biomimetic platform for chemo/photodynamic combination therapy against osteosarcoma

Clinical treatment for osteosarcoma (OS) is still lacking effective means, and no significant progress in OS treatment have been made in recent years. Single chemotherapy has serious side effects and can produce drug resistance easily, resulting poor therapeutic effect. As a modern and non-invasive treatment form, photodynamic therapy (PDT) is widely used to treat diverse cancers. Chemotherapy in combination with PDT is a particularly efficient antitumor method that could overcome the defects of monotherapies. Since mitochondria is a key subcellular organelle involved in cell apoptosis regulation, targeting tumor cells mitochondria for drug delivery has become an important entry point for anti-tumor therapy. Herein, we rationally designed a core-shell structured biomimetic nanoplatform, i.e., D@SLNP@OSM-IR780, to achieve tumor homologous targeting and mitochondria targeted drug release for chemotherapy combined with PDT against OS. Upon 808 nm laser irradiation, D@SLNP@OSM-IR780 exhibited excellent photo-cytotoxicity in vitro. The excellent targeting effect of D@SLNP@OSM-IR780 in tumor tissues produced a tumor inhibition rate of 98.9% in vivo. We further indicated that synergistic chemo-photodynamic effect induced by D@SLNP@OSM-IR780 could activate mitochondria-mediated apoptosis pathway, along with host immune response and potential photothermal effect. On the whole, D@SLNP@OSM-IR780 is revealed to be a promising platform for OS targeted combination therapeutics.

Extent of Surgery and Survival of Osteosarcoma: A Retrospective Population-Based Study

Background Osteosarcoma (OSC) is the most common primary bone tumor and is often managed surgically. Few prior investigations have assessed differences in OSC survival by specific surgical techniques at a national registry level. We sought to compare survival based on surgical subtypes for OSC patients in the Surveillance, Epidemiology, and End Results (SEER) database. Methodology We searched the SEER database for malignant OSCs diagnosed between 2000 and 2019 which were surgically managed. Separate survival comparisons were made for one and five years for wide excision (local tumor destruction or resection versus partial resection) and radical excision (radical resection with limb-sparing versus limb amputation with or without girdle resection). Results A total of 4,303 patients were included, of whom 3,587 were surgically managed. There were no survival differences between local destruction and partial resection (hazard ratio = 0.826, p = 0.303). However, younger age, lower staging, and management without radiation were associated with improved survival. The radical excision comparison showed limb amputation was associated with worse survival than limb-sparing surgery (hazard ratio = 1.531, p < 0.001). Younger age, female sex, lower stage, receipt of chemotherapy, and neoadjuvant plus adjuvant chemotherapy were associated with improved survival while Black and American Indian or Alaska Native were associated with worse survival. Conclusions Our findings show that patients managed with limb-sparing radical resection survived significantly compared to limb amputation. There were no differences in survival for wide excision surgeries. The use of a combination of neoadjuvant and adjuvant chemotherapy also yields improved survival. OSC survival may be optimized with limb-sparing surgery with a combination of neoadjuvant and adjuvant chemotherapy.

Discovery of potent thiazolidin-4-one sulfone derivatives for inhibition of proliferation of osteosarcoma in vitro and in vivo

Chemotherapy combining with surgical treatment has been the main strategy for osteosarcoma treatment in clinical. Due to unclear pathogenesis and unidentified drug targets, significant progress has not been made in the development of targeted drugs for osteosarcoma during the past 50 years. Our previous discovery reported compound R-8i with a high potency for the treatment of osteosarcoma by phenotypic screening. However, both the metabolic stability and bioavailability of R-8i are poor (T1/2 = 5.36 min, mouse liver microsome; and bioavailability in vivo F = 52.1 %, intraperitoneal administration) which limits it use for further drug development. Here, we described an extensive structure-activity relationship study of thiazolidine-4-one sulfone inhibitors from R-8i, which led to the discovery of compound 68. Compound 68 had a potent cellular activity with an IC50 value of 0.217 μM, much higher half-life (T1/2 = 73.8 min, mouse liver microsome) and an excellent pharmacokinetic profile (in vivo bioavailability F = 115 %, intraperitoneal administration). Compound 68 also showed good antitumor effects and low toxicity in a xenograft model (44.6 % inhibition osteosarcoma growth in BALB/c mice). These results suggest that compound 68 is a potential drug candidate for the treatment of osteosarcoma.

Immunotherapy Innovations in the Fight against Osteosarcoma: Emerging Strategies and Promising Progress

Immunosuppressive elements within the tumor microenvironment are the primary drivers of tumorigenesis and malignant advancement. The presence, as well as the crosstalk between myeloid-derived suppressor cells (MDSCs), osteosarcoma-associated macrophages (OS-Ms), regulatory T cells (Tregs), and endothelial cells (ECs) with osteosarcoma cells cause the poor prognosis of OS. In addition, the consequent immunosuppressive factors favor the loss of treatment potential. Nanoparticles offer a means to dynamically and locally manipulate immuno-nanoparticles, which present a promising strategy for transforming OS-TME. Additionally, chimeric antigen receptor (CAR) technology is effective in combating OS. This review summarizes the essential mechanisms of immunosuppressive cells in the OS-TME and the current immune-associated strategies. The last part highlights the limitations of existing therapies and offers insights into future research directions.

Prognostic and predictive value of super-enhancer-derived signatures for survival and lung metastasis in osteosarcoma

BACKGROUND

Risk stratification and personalized care are crucial in managing osteosarcoma due to its complexity and heterogeneity. However, current prognostic prediction using clinical variables has limited accuracy. Thus, this study aimed to explore potential molecular biomarkers to improve prognostic assessment.

METHODS

High-throughput inhibitor screening of 150 compounds with broad targeting properties was performed and indicated a direction towards super-enhancers (SEs). Bulk RNA-seq, scRNA-seq, and immunohistochemistry (IHC) were used to investigate SE-associated gene expression profiles in osteosarcoma cells and patient tissue specimens. Data of 212 osteosarcoma patients who received standard treatment were collected and randomized into training and validation groups for retrospective analysis. Prognostic signatures and nomograms for overall survival (OS) and lung metastasis-free survival (LMFS) were developed using Cox regression analyses. The discriminatory power, calibration, and clinical value of nomograms were evaluated.

RESULTS

High-throughput inhibitor screening showed that SEs significantly contribute to the oncogenic transcriptional output in osteosarcoma. Based on this finding, focus was given to 10 SE-associated genes with distinct characteristics and potential oncogenic function. With multi-omics approaches, the hyperexpression of these genes was observed in tumor cell subclusters of patient specimens, which were consistently correlated with poor outcomes and rapid metastasis, and the majority of these identified SE-associated genes were confirmed as independent risk factors for poor outcomes. Two molecular signatures were then developed to predict survival and occurrence of lung metastasis: the SE-derived OS-signature (comprising LACTB, CEP55, SRSF3, TCF7L2, and FOXP1) and the SE-derived LMFS-signature (comprising SRSF3, TCF7L2, FOXP1, and APOLD1). Both signatures significantly improved prognostic accuracy beyond conventional clinical factors.

CONCLUSIONS

Oncogenic transcription driven by SEs exhibit strong associations with osteosarcoma outcomes. The SE-derived signatures developed in this study hold promise as prognostic biomarkers for predicting OS and LMFS in patients undergoing standard treatments. Integrative prognostic models that combine conventional clinical factors with these SE-derived signatures demonstrate substantially improved accuracy, and have the potential to facilitate patient counseling and individualized management.

m6A-modified circARHGAP12 promotes the aerobic glycolysis of doxorubicin-resistance osteosarcoma by targeting c-Myc

Chemotherapy resistance accompanied by energy metabolism abnormality functions as one of the main reasons for treatment failure and poor prognosis. However, the function of N6-methyladenosine (m6A)-modified circular RNA (circRNA) on osteosarcoma (OS) is still unclear. Here, present research investigated the potential role and mechanism of circARHGAP12 on OS doxorubicin (Dox) resistance and aerobic glycolysis. Results indicated that circARHGAP12 was a novel m6A-modified circRNA, which was up-regulated in OS cells. Overexpression of circARHGAP12 promoted the Dox resistance half-maximal inhibitory concentration (IC50) and aerobic glycolysis (glucose uptake, lactate and ATP production) in OS cells (Saos-2/Dox, MG63/Dox). Mechanistically, m6A-modified circARHGAP12 could bind with c-Myc mRNA through m6A-dependent manner, thereby enhancing the c-Myc mRNA stability. Thus, these findings revealed the critical function of circARHGAP12 on OS Dox-resistance and aerobic glycolysis. Taken together, our study demonstrated a critical function of circARHGAP12 on OS chemotherapy resistance and energy metabolism abnormality, providing critical roles on OS treatment.

PNO1 promotes the progression of osteosarcoma via TGF-β and YAP/TAZ pathway

This study aimed to explore the potential role and mechanisms of the partner of NOB1 homolog (PNO1) in osteosarcoma. The expression of PNO1 in tumor and adjacent tissue samples was examined using western blotting. Lentiviral transfection was used to establish sh-Ctrl and sh-PNO1 osteosarcoma cell lines. MTT assay, Celigo cell cytometer count, and cell colony formation assay were used to investigate the proliferation of osteosarcoma cells in vitro, whereas xenotransplantation assay was performed for in vivo experiments. Wound-healing and Transwell assays were chosen to verify the migration and invasion of osteosarcoma cells. Flow cytometry assay and caspase-3/7 activity analysis were adopted for the analysis of cell apoptosis and cell cycle. Finally, transcriptome sequencing and bioinformatics analysis were adopted to explore the acting mechanisms. The expression of PNO1 was higher in osteosarcoma tissues than that in adjacent tissues. Down-regulation of PNO1 inhibited the proliferation, migration, and invasion, and induced cell apoptosis and cell cycle arrest of osteosarcoma cells. Furthermore, according to transcriptome sequencing and Kyoto Encyclopedia of Genes and Genomes pathway analysis, we found that PNO1 might affect the progression of osteosarcoma via TGF-β and YAP/TAZ signaling pathways. PNO1 could be a potential target for osteosarcoma treatment.

METTL3-mediated m6A modification of circRNF220 modulates miR-330-5p/survivin axis to promote osteosarcoma progression

BACKGROUND

Circular RNAs (circRNAs) play a crucial role in regulating various physiological processes. However, the precise regulatory mechanisms of circRNF220s in osteosarcoma (OS) are not well understood.

METHODS

The abundances of circRNF220, miR-330-5p, and survivin were determined using qRT-PCR. To assess the m6A accumulation in circRNF220, a methylated RNA immunoprecipitation (Me-RIP) assay was conducted. Cellular multiplication, motility, and invasion were examined using the cell Counting Kit-8 (CCK-8), EdU, colony formation, Transwell, and wound-healing assays. The binding relationships were measured through RNA immunoprecipitation (RIP) and luciferase reporter assays. In vivo functionality was assessed using xenograft models.

RESULTS

CircRNF220 was identified as being overexpressed in both OS cells and tissues. In vitro experiments demonstrated that silencing circRNF220 impeded the proliferation, invasion, and motility of OS cells. Similarly, in vivo studies confirmed that downregulating circRNF220 inhibited the growth of OS. Further mechanistic investigations unveiled that METTL3-modulated circRNF220 regulated the progression of OS by upregulating survivin expression through acting as a sponge for miR-330-5p.

CONCLUSION

The modulation of METTL3-regulated circRNF220 has been found to promote the progression of OS by modulating the miR-330-5p/survivin axis. This novel finding suggests a potentially unique approach to managing OS.

Tumors and infections of the growing spine

The growing spine differs from the adult spine in several ways. Although tumors and infections cause only a small percentage of pediatric back pain incidences, delayed proper diagnosis and treatment may be disastrous. Benign lesions, such as osteoid osteoma, osteoblastoma, and aneurysmal bone cyst in the spine, are predominant during the first two decades of life, whereas malignant bony spinal tumors are rare. In the pediatric population, malignant spine tumors include osteosarcoma, Ewing's sarcoma, lymphoma, and metastatic neuroblastoma. Infections of the growing spine are rare, with the incidence of discitis peaking in patients under the age of 5 years and that of vertebral osteomyelitis peaking in older children. Spondylodiscitis is often a benign, self-limiting condition with low potential for bone destruction. Conservative treatments, including bedrest, immobilization, and antibiotics, are usually sufficient. Spinal tuberculosis is a frequently observed form of skeletal tuberculosis, especially in developing countries. Indications for surgical treatment include neurologic deficit, spinal instability, progressive kyphosis, late-onset paraplegia, and advanced disease unresponsive to nonoperative treatment. Spinal tumors and infections should be considered potential diagnoses in cases with spinal pain unrelated to the child's activity, accompanied by fever, malaise, and weight loss. In spinal tumors, early diagnosis, fast and adequate multidisciplinary management, appropriate en bloc resection, and reconstruction improve local control, survival, and quality of life. Pyogenic, hematogenous spondylodiscitis is the most common spinal infection; however, tuberculosis-induced spondylodiscitis should also be considered. Level of evidence: level 4.

Urolithin B inhibits proliferation and migration and promotes apoptosis and necrosis by inducing G2/M arrest and targeting MMP-2/-9 expression in osteosarcoma cells

Osteosarcoma (OS) is the most prevalent primary bone cancer, with a high morbidity and mortality rate. Over the past decades, therapeutic approaches have not considerably improved patients' survival rates, and further research is required to find efficient treatments for OS. Data from several studies have shown that urolithin B (UB), the intestinal metabolite of polyphenolic ellagitannins, is emerging as a new class of anticancer compounds, yet its effect on OS cancer cells remains elusive. Herein, we investigated UB's antimetastatic, antiproliferative, and apoptotic effects on the MG-63 OS cell line. Cell viability assay, annexin V/propidium iodide staining, cell cycle arrest analysis, determination of the gene expression of MMP-2, MMP-9, Bax, Bcl-2, and p53 messenger RNA (mRNA), evaluation of reactive oxygen species (ROS) generation and migration, and MMP-2 and MMP-9 protein expression assessments were performed. UB caused late apoptosis, necrosis, G2/M arrest, and ROS generation in MG-63 cells. It increased the mRNA expression of the p53 tumor suppressor and Bax proapoptotic genes. UB also inhibited the migration and metastatic behavior of MG-63 OS cells by downregulating mRNA and MMP-2 and MMP-9 protein expression. In general, although further in vivo investigations are warranted, the current results showed that UB might be utilized as a potential novel natural compound for OS therapy due to its nontoxic, antiproliferative, and antimetastatic nature.

Biological Prosthesis (Hollow 3D-Printed Titanium Custom-Made Prosthesis and Bone Graft) for Humeral Reconstruction in Pediatric Oncologic Patients: Surgical Indications and Results

This study presents the mid-term outcomes of a novel "biological prosthesis" for pediatric humerus reconstruction after major bone tumor removal. This approach involves a hollow 3D-printed titanium custom-made prosthesis combined with bone grafting. The primary aim was to preserve and revitalize the unaffected autologous proximal or distal humeral stump. Between 2017 and 2021, we treated five pediatric patients (mean age 11.2 years; range 7-17) with humeral bone sarcomas. A one-stage surgical procedure involved tumor resection and implanting a hollow 3D-printed custom-made prosthesis. In two cases, we preserved the proximal humerus; in two, the distal part; and in one, both. Graft materials included homologous bone chips in three cases and free vascularized fibular grafts in two cases. All patients were clinically and radiographically assessed after a mean follow-up of 32.2 months (range of 14-68). No significant complications were observed, and no implant revisions were needed. Osseointegration was evident in all cases within eight months post-surgery; vascular support for the remaining autologous stump was demonstrated in all cases. Our hollow 3D-printed custom-made prosthesis and bone grafting offer the potential for partial or complete articular surface preservation. This approach encourages revascularization of the epiphysis, leading to satisfactory outcomes in humerus reconstruction within the pediatric population.

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 Property of Digera muricata Leaf Extract: An In Vitro Study

Aim The aim was to evaluate the anticancer potential of Digera muricata ethanolicleaf extract on MG-63 osteosarcoma cell lines. Materials and methods The anti-cancer properties of Digera muricata ethanolic leaf extract were evaluated on osteosarcoma cell lines using 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the morphological changes in MG-63 cells were assessed after 24 hours using microscopic observation. Additionally, fluorescence microscopy was employed to evaluate the apoptotic changes after acridine orange/ethidium bromide (AO/EtBr) dual staining. Results The MTT assay revealed a dose-dependent cell death. The cell viability decreased with increase in concentrations of the extract, The cell viability was 89.98 ± 4.89 percentage at 25 μg/ml and 15.64 ± 3.64 percentage at 200 μg/ml concentrations. A concentartion of 116.95 μg/ml showed 50% inhibition (IC50). The morphological and dual staining studies also showed the extract's effectiveness in inducing apoptosis. Conclusion The ethanolic leaf extract of D. muricata could impart good antiproliferative activity in MG-63 cell lines. The extract could also induce apoptosis and hence, it may be considered as a potential anticancer agent for the development of drug formulation for the treatment of osteosarcoma.

Amplified Ferroptosis and Apoptosis Facilitated by Differentiation Therapy Efficiently Suppress the Progression of Osteosarcoma

Osteosarcoma (OS) is the most frequent osseous neoplasm among young people aged 10-20. Currently, the leading treatment for osteosarcoma is a combination of surgery and chemotherapy. However, the mortality remains high due to chemoresistance, metastasis, and recurrence, attributing to the existence of cancer stem cells (CSCs) as reported. To target CSCs, differentiation therapy attracts increasing attention, inducing CSCs to bulk tumor cells with elevated reactive oxygen species (ROS) levels and less chemoresistance. Moreover, increasing studies have implied that ferroptosis is a promising approach to eliminating cancer cells through eliciting oxidative damage and subsequent apoptosis, effectively bypassing chemoresistance. Here, a cancer-cell-membrane-decorated biocompatible formulation (GA-Fe@CMRALi liposome) is constructed to combat OS efficiently by combining distinct differentiation and ferroptosis therapies through magnified ROS-triggered ferroptosis and apoptosis with homologous target capability to tumor sites. The combinational approach exhibited favorable therapeutic efficacy against OS in vitro and in vivo. Impressively, the potential mechanisms are revealed by mRNA sequencing. This study provides a tactical design and typical paradigm of the synergized differentiation and ferroptosis therapies to combat heterogeneous OS.

Research progress in the mechanism and treatment of osteosarcoma

ABSTRACT

Osteosarcoma (OS) is the most common primary malignant bone tumor that more commonly occurs in children and adolescents. The most commonly used treatment for OS is surgery combined with chemotherapy, but the treatment outcomes are typically unsatisfactory. High rates of metastasis and post-treatment recurrence rates are major challenges in the treatment of OS. This underlines the need for studying the in-depth characterization of the pathogenetic mechanisms of OS and development of more effective therapeutic modalities. Previous studies have demonstrated the important role of the bone microenvironment and the regulation of signaling pathways in the occurrence and development of OS. In this review, we discussed the available evidence pertaining to the mechanisms of OS development and identified therapeutic targets for OS. We also summarized the available treatment modalities for OS and identified future priorities for therapeutics research.

Eugenol: In Vitro and In Ovo Assessment to Explore Cytotoxic Effects on Osteosarcoma and Oropharyngeal Cancer Cells

Cancer is a significant health problem worldwide; consequently, new therapeutic alternatives are being investigated, including those found in the vegetable kingdom. Eugenol (Eug) has attracted attention for its therapeutic properties, especially in stomatology. The purpose of this study was to investigate the cytotoxicity of Eug, in vitro, on osteosarcoma (SAOS-2) and oropharyngeal squamous cancer (Detroit-562) cells, as well as its potential irritant effect in ovo at the level of the chorioallantoic membrane (CAM). The data obtained following a 72 h Eug treatment highlighted the reduction in cell viability up to 41% in SAOS-2 cells and up to 37% in Detroit-562 cells, respectively. The apoptotic-like effect of Eug was indicated by the changes in cell morphology and nuclear aspect; the increase in caspase-3/7, -8 and -9 activity; the elevated expression of Bax and Bad genes; and the increase in luminescence signal (indicating phosphatidylserine externalization) that preceded the increase in fluorescence signal (indicating the compromise of membrane integrity). Regarding the vascular effects, slight signs of coagulation and vascular lysis were observed, with an irritation score of 1.69 for Eug 1 mM. Based on these results, the efficiency of Eug in cancer treatment is yet to be clarified.

ANXA2 and Rac1 negatively regulates autophagy and osteogenic differentiation in osteosarcoma cells to confer CDDP resistance

BACKGROUND

Cisplatin (CDDP) is a mainstay chemotherapeutic agent for OS treatment, but drug resistance has become a hurdle to limit its clinical effect. Autophagy plays an important role in CDDP resistance in OS, and in the present study we explored the role of ANXA2 and Rac1 in dictating CDDP sensitivity in OS cells.

METHODS

ANXA2 and Rac1 expression levels were examined by Western blot and autophagy induction was detected by transmission electron miscroscope (TEM) in the clinical samples and OS cell lines. CDDP resistant cells were established by exposing OS cells to increasing doses of CDDP. The effects of ANXA2 and Rac1 knockdown on CDDP sensitivity were evaluated in the cell and animal models.

RESULTS

Reduced autophagy was associated with the increased expression of ANXA2 and Rac1 in CDDP resistant OS tumor samples and cells. Autophagy suppression promoted CDDP resistance and inducing autophagy re-sensitized the resistant cells to CDDP treatment in vitro and in vivo. Further, knocking down ANXA2 or Rac1 re-activated autophagy and attenuated CDDP resistance in OS cells. We further demonstrated that CDDP resistant OS cells displayed a poorer osteogenic differentiation state when compared to the parental cell lines, which was significantly reversed by autophagy re-activation and ANXA2 or Rac1 silencing.

CONCLUSION

Our findings revealed a complicated interplay of ANXA2/Rac1, autophagy induction, and osteogenic differentiation in dictating CDDP resistance in OS cells, suggesting ANXA2 and Rac1 as promising targets to modulate autophagy and overcome CDDP resistance in OS cells.

Hsa_circ_0000073 promotes lipid synthesis of osteosarcoma through hsa-miR-1184/ FADS2 pathway

PURPOSE

Osteosarcoma is one of the leading causes of cancer mortality in children and teenagers. Dysregulation of lipid metabolism has been reported to involve tumor progression. Our previous evidence has revealed that circular RNA hsa_circ_0000073 enhanced the proliferation and metastasis of osteosarcoma cells. However, the effect of hsa_circ_0000073 on the lipid metabolism of osteosarcoma remains unclear. In this paper, we focused on the effect of hsa_circ_0000073 in lipid metabolism and investigated a network among hsa_circ_0000073/ miR-1184 /FADS2 in osteosarcoma, which provides a new idea to treat osteosarcoma.

METHODS

The osteosarcoma and its adjacent tissue samples were collected for further validation. qRT-PCR or western blot was employed to detect the expression of hsa_circ_0000073, miR-1184, and FADS2 in OS cells and tissues. Microarray analysis, mass spectrometry, metabolomics analysis, and bioinformatics analysis were used to explore the potential function and target gene of hsa_circ_0000073. Oil red o, Nile red staining, and Triglyceride content assay were adopted to confirm the effect of hsa_circ_0000073 on the lipid metabolism of OS. Dual-luciferase reporter assays and RNA immunoprecipitation were applied to construct and validate the ceRNA network of hsa_circ_0000073. The xenograft mouse model was taken to verify the effect of hsa_circ_0000073 on lipid metabolism in vivo.

RESULTS

The results confirmed that hsa_circ_0000073 was raised in the tumor tissues more than its adjacent tissue. Moreover, the higher expression of hsa_circ_0000073 was associated with worse survival rates, advanced clinical stage, large tumor size, and metastasis. After hsa_circ_0000073 silence, the gene chip and metabolomics result implied that hsa_circ_0000073 expression is positively correlated with a 91 genes signature and 78 metabolites in MG-63 and Saos-2 cells. The bioinformatics analysis indicated that hsa_circ_0000073 might involve in the biological processes of lipid metabolism. Further loss and gain of function experiments affirmed that hsa_circ_0000073 could impact cell lipid synthesis. Mechanically, hsa_circ_0000073 favored the expression of FADS2 genes by sponging miR-1184. Consistent with these observations, silencing of hsa_circ_0000073 inhibited lipid synthesis in vivo xenograft mouse model.

CONCLUSIONS

Our study revealed that hsa_circ_0000073 contributed to the lipid synthesis of osteosarcoma by decreasing the expression of miR-1184, thereby increasing FADS2, which provides new insights into treating osteosarcoma.

Osteosarcoma Explorer: A Data Commons With Clinical, Genomic, Protein, and Tissue Imaging Data for Osteosarcoma Research

PURPOSE

Osteosarcoma research advancement requires enhanced data integration across different modalities and sources. Current osteosarcoma research, encompassing clinical, genomic, protein, and tissue imaging data, is hindered by the siloed landscape of data generation and storage.

MATERIALS AND METHODS

Clinical, molecular profiling, and tissue imaging data for 573 patients with pediatric osteosarcoma were collected from four public and institutional sources. A common data model incorporating standardized terminology was created to facilitate the transformation, integration, and load of source data into a relational database. On the basis of this database, a data commons accompanied by a user-friendly web portal was developed, enabling various data exploration and analytics functions.

RESULTS

The Osteosarcoma Explorer (OSE) was released to the public in 2021. Leveraging a comprehensive and harmonized data set on the backend, the OSE offers a wide range of functions, including Cohort Discovery, Patient Dashboard, Image Visualization, and Online Analysis. Since its initial release, the OSE has experienced an increasing utilization by the osteosarcoma research community and provided solid, continuous user support. To our knowledge, the OSE is the largest (N = 573) and most comprehensive research data commons for pediatric osteosarcoma, a rare disease. This project demonstrates an effective framework for data integration and data commons development that can be readily applied to other projects sharing similar goals.

CONCLUSION

The OSE offers an online exploration and analysis platform for integrated clinical, molecular profiling, and tissue imaging data of osteosarcoma. Its underlying data model, database, and web framework support continuous expansion onto new data modalities and sources.

Betanin inhibits PI3K/AKT/mTOR/S6 signaling pathway, cell growth and death in osteosarcoma MG-63 cells

It is possible to develop new chemopreventive compounds so that cancer cells can be targeted in an exclusive manner. Bioactive natural compounds have demonstrated to be efficient chemotherapeutic agents, safe and cost-effective. Majority of anti-cancer medications are derived from natural sources, particularly of plant origins. Betanin (betanidin-5-O-β-glucoside) is the most common betacyanin with antioxidant, anti inflammatory and anticancer properties. The present study therefore investigated the effect of betanin onosteosarcoma MG-63 cells. The mechanistic pathway of inflammatory responses, cell proliferation and apoptosis were investigated. The MG-63 cells were treated with betanin for 24 h. Betanin actions on the appearance of cell arrangements, morphological changes, ROS induced Δψm , cell migration, cell adhesion and proliferative mechanistic marker expression of PI3K/AKT/mTOR/S6were analyzed. Betanin inhibited MG-63 cells at IC50 concentrations between 9.08 and 54.49 μM and induced apoptosis by triggering the ROS mechanism. Betanin inhibited proliferation and migration of MG-63 cells and induced DNA fragmentation. Betanin also modified the key mediator expression levels of PI3K/AKT/mTOR/S6 signaling pathways. Betanin can potentially be utilized in bone carcinoma therapeutics to inhibit, reverse or delay osteosarcoma.