Osteosarcoma

Rotenone inhibited osteosarcoma metastasis by modulating ZO-2 expression and location via the ROS/Ca2+/AMPK pathway

BACKGROUND

Pulmonary metastases in osteosarcoma (OS) are associated with a poor prognosis. Rotenone has shown anti-cancer activity. However, its effects on metastasis and the underlying mechanisms remain unknown. This study investigated the potential use of Rotenone for OS treatment.

METHODS

The effect of Rotenone and ROS/Ca2+/AMPK/ZO-2 pathway on metastasis and EMT was evaluated by Western blot, Transwell and Wound healing. Flow cytometer was employed to measure the intracellular Ros and Ca2+ levels. The subcellular location of ZO-2 was detected by IF, interaction between AMPK and ZO-2 were examined by Co-IP. Then, subcutaneous tumor and metastasis models were used to evaluate the function of Rotenone in OS metastasis.

RESULTS

Rotenone-induced ROS led to increased intracellular Ca2+, which promoted the EMT of OS cells through activation of AMPK and ZO-2 nuclear translocation. Inhibition of ROS production decreased intracellular Ca2+, restraining AMPK activity. Knock-down of ZO-2 significantly suppressed the anti-metastasis effects of Rotenone in OS cells. Moreover, Rotenone elevated p-AMPK and ZO-2 expression but inhibited EMT and lung metastasis in vivo.Conclusion These results provide evidence supporting an anti-metastatic effect of Rotenone. These findings support the use of Rotenone in the prevention of OS metastasis.

STUB1-mediated ubiquitination of SLC25A10 regulates mitochondrial function and drives osteosarcoma progression: A novel therapeutic target

Osteosarcoma (OS) is a highly aggressive primary bone malignancy characterized by limited treatment options and poor clinical outcomes. Emerging evidence underscores the critical role of mitochondrial metabolism in tumor progression, positioning mitochondrial proteins as potential therapeutic targets. SLC25A10, a mitochondrial dicarboxylate carrier involved in redox homeostasis and fatty acid synthesis, has been implicated in various cancers; however, its role in OS remains unclear.In this study, we investigated the function of SLC25A10 in OS progression and its potential as a therapeutic target. Our results revealed that SLC25A10 expression is significantly upregulated in OS tissues and cell lines compared to normal bone tissue, and its elevated expression is associated with poor patient prognosis. Functional assays demonstrated that silencing SLC25A10 via shRNA or CRISPR/Cas9 significantly suppressed OS cell proliferation, migration, and mitochondrial function, resulting in mitochondrial membrane depolarization, oxidative damage, and apoptosis. In contrast, SLC25A10 overexpression promoted OS cell proliferation and migration. In vivo, knockout of SLC25A10 markedly inhibited the growth of subcutaneous OS xenografts in nude mice.Furthermore, we identified STUB1, an E3 ubiquitin ligase, as a negative regulator of SLC25A10. STUB1 knockdown reduced the ubiquitination of SLC25A10, leading to increased protein stability and elevated expression. Notably, lysine 254 (K254) was identified as a key site mediating STUB1-dependent ubiquitination of SLC25A10. STUB1-mediated downregulation of SLC25A10 suppressed OS cell proliferation and migration, indicating a tumor-suppressive role for STUB1 in OS through modulation of SLC25A10.Collectively, our findings demonstrate that SLC25A10 is essential for maintaining mitochondrial function and contributes to OS malignancy. Targeting SLC25A10 may represent a novel and promising therapeutic strategy for the treatment of osteosarcoma.

Enhanced sequential osteosarcoma therapy using a 3D-Printed bioceramic scaffold combined with 2D nanosheets via NIR-II photothermal-chemodynamic synergy

Background

Osteosarcoma (OS) is a malignant tumor originating from primitive mesenchymal cells, characterized by rapid metastasis, high invasiveness, and significant mortality. The primary challenges in OS management include the effective elimination of residual tumor cells to prevent recurrence and the repair of extensive bone defects caused by surgical intervention.

Objective

This study aims to develop an innovative biomimetic 3D-printed bioactive glass ceramic (BGC) scaffold modified with two-dimensional nanosheets to address both tumor ablation and bone tissue repair.

Materials and methods

The nanosheets were constructed via ellagic acid (EA) and ruthenium (Ru) coordination, leveraging the non-topological adhesion properties of catechol in EA to deposit the nanosheets onto the BGC scaffold (EARu-BGC). The therapeutic effects of EARu-BGC were evaluated in vitro and in vivo.

Results

EARu-BGC sequentially responds to the local microenvironment during OS treatment. During the tumor ablation phase, EARu-BGC induced ferroptosis through the synergistic effects of photothermal and chemodynamic therapy, achieving over 90 % tumor cell ablation and significantly inhibiting tumor volume and weight. In the bone tissue repair phase, EARu-BGC exhibited adaptive ROS scavenging and facilitated a pro-healing microenvironment, promoting osteogenic differentiation. The gradual degradation of the BGC scaffold provided essential minerals and space for new bone formation. In vivo experiments demonstrated that EARu-BGC significantly enhanced osteogenesis, increasing the trabecular number to 1.51 ± 0.15/mm and reducing trabecular separation to 1.50 ± 0.04 mm.

Conclusion

The EARu-BGC scaffold presents a promising multifunctional platform for OS treatment by effectively balancing antitumor efficacy with bone repair capabilities.

The role of RGS12 in tissue repair and human diseases

Regulator of G protein signaling 12 (RGS12) belongs to the superfamily of RGS proteins defined by a conserved RGS domain that canonically binds and deactivates heterotrimeric G-proteins. As the largest family member, RGS12 is widely expressed in many cells and tissues. In the past few decades, it has been found that RGS12 affects the activity of various cells in the human body, participates in many physiological and pathological processes, and plays an important role in the pathogenesis of many diseases. Here, we set out to comprehensively review the role of RGS12 in human diseases and its mechanisms, highlighting the possibility of RGS12 as a therapeutic target for the treatment of human diseases.

MOPSOGAT: Predicting CircRNA-Disease Associations via Improved Multi-objective Particle Swarm Optimization and Graph Attention Network

Recently increasing researches have discovered that circRNAs are remarkably reliable in organisms and play a crucial role as marker in many diseases. Although deep learning techniques has been universally applied to investigate the relationship of circRNA-disease, optimizing many parameters involved in these techniques for best performance has been a challenge. Therefore, we present, for the first time, a multi-objective particle swarm optimization algorithm to optimize the parameters in a graph attention network, ensuring that the model operates at peak efficiency. In addition, it also limits feature learning due to uneven distribution of different node types in heterogeneous graphs based on association relationships. We suggest a unique approach, MOPSOGAT, to overcome the aforementioned problems. MOPSOGAT is a method for predicting circRNA-disease associations utilizing the improved multi-objective particle swarm optimization (MOPSO) and the graph attention network. Initially, we obtain node sequences by utilizing multiple circRNA similarities and disease phenotypic similarities, and employing a heterogeneous graph with random walks incorporating jump and stay strategies. These sequences are then processed using word2vec to derive the neighbor vectors of the nodes, thus providing initial embeddings for circRNAs and diseases. Subsequently, in order to model convergence and diversity of the Pareto front solutions, an improved MOPSO algorithm is used to iteratively search for optimal solutions in the parameter space. After MOPSO optimization, parameters are fed into a graph attention network to further refine the model embedding. As a result, MOPSOGAT performs better than deep learning based methods, solely multi-objective optimization-based methods and machine learning-based ways. Moreover, the potential associations predicted by MOPSOGAT have been validated through case studies, further demonstrating the potential of MOPSOGAT in future biomedical research.

Overcoming drug resistance in osteosarcoma with MTX-CuB-NLC: An in vitro and in vivo study

Osteosarcoma (OS) is the predominant bone tumor affecting pediatric and adolescent populations. The standard treatment regimen involves preoperative chemotherapy, surgical intervention, and postoperative chemotherapy. Methotrexate (MTX) serves as the first-line pharmacological agent for OS treatment; however, the emergence of tumor resistance to chemotherapeutic agents poses a significant challenge. Cucurbitacin B (CuB) exhibits intrinsic anti-OS properties and can synergistically enhance OS suppression by reversing drug resistance and augmenting the therapeutic effects of MTX. Nevertheless, the clinical application of CuB and MTX is hindered by their low aqueous solubility, necessitating the development of an effective drug delivery system to precisely target tumor tissues and maximize therapeutic efficacy. Consequently, this study focuses on the development of a nanostructured lipid carrier (NLC) co-loaded with MTX and CuB (MTX-CuB-NLC) to address these limitations. MTX-CuB-NLC is characterized as a spherical nanoparticle with a mean particle size of 44.13 ± 1.40 nm, a polydispersity index (PDI) of 0.279 ± 0.120, and a zeta potential of -17.10 ± 4.98 mV. The encapsulation efficiency (EE%) and drug loading (DL%) were determined to be 61.03 ± 2.40 % and 0.25 ± 0.02 % for MTX, and 81.02 ± 1.61 % and 0.23 ± 0.02 % for CuB, respectively. The formulation demonstrated substantial storage stability over a 14-day period. In vitro release studies indicated that MTX-CuB-NLC possesses sustained release capabilities. Furthermore, the nanoparticle exhibited significantly enhanced uptake and cytotoxicity against U-2 OS cells compared to the free drug. Notably, MTX-CuB-NLC displayed pronounced cytotoxic effects on methotrexate-resistant U-2 OS cells (U-2 OS/MTX), underscoring its potential to induce apoptosis and circumvent multidrug resistance in these cells. In an OS nude mouse model exhibiting drug resistance, MTX-CuB-NLC demonstrated superior tumor targeting and suppression efficacy. This research has culminated in the development of an effective continuous drug delivery system for osteosarcoma, presenting a promising strategy to combat drug resistance in this malignancy.

Recent Research on the Role of Phytochemicals from Ginseng in Management of Osteosarcoma, Osteoporosis, and Osteoarthritis

Ginseng phytochemicals have attracted considerable attention for their potential therapeutic applications in bone-related diseases including osteosarcoma, osteoporosis, and osteoarthritis. Recent research has highlighted the promising effects of ginsenosides and polysaccharides from ginseng by studying multi-target effects and combination therapies in osteosarcoma progression. Beyond osteosarcoma, ginseng phytochemicals have been explored for their effects on osteoporosis. Various ginsenosides and ginseng extract were shown to regulate signaling pathways involved in activating osteoblast and inhibiting osteoclast in vitro and in vivo models. Ginseng ginsenosides have also demonstrated potential anti-osteoarthritic properties. Recent studies discussed how ginsenoside reduced inflammation and cartilage degradation as a therapeutic candidate for osteoarthritis management. In this review, we examine the anti-osteosarcoma, anti-osteoporotic, and anti-osteoarthritic activities of ginseng-derived phytochemicals reported in studies published between 2014 and 2024. This review also provides a comprehensive overview of the working mechanisms of these compounds in various model systems. Furthermore, we address the limitations of current research approaches and outline future directions to maximize the therapeutic application of ginseng phytochemicals in the management of bone-related diseases.

Multiscale metal-based nanocomposites for bone and joint disease therapies

Bone and joint diseases are debilitating conditions that can result in significant functional impairment or even permanent disability. Multiscale metal-based nanocomposites, which integrate hierarchical structures ranging from the nanoscale to the macroscale, have emerged as a promising solution to this challenge. These materials combine the unique properties of metal-based nanoparticles (MNPs), such as enzyme-like activities, stimuli responsiveness, and photothermal conversion, with advanced manufacturing techniques, such as 3D printing and biohybrid systems. The integration of MNPs within polymer or ceramic matrices offers a degree of control over the mechanical strength, antimicrobial efficacy, and the manner of drug delivery, whilst concomitantly promoting the processes of osteogenesis and chondrogenesis. This review highlights breakthroughs in stimulus-responsive MNPs (e.g., photo-, magnetically-, or pH-activated systems) for on-demand therapy and their integration with biocomposite hybrids containing cells or extracellular vesicles to mimic the native tissue microenvironment. The applications of these composites are extensive, ranging from bone defects, infections, tumors, to degenerative joint diseases. The review emphasizes the enhanced load-bearing capacity, bioactivity, and tissue integration that can be achieved through hierarchical designs. Notwithstanding the potential of these applications, significant barriers to progress persist, including challenges related to long-term biocompatibility, regulatory hurdles, and scalable manufacturing. Finally, we propose future directions, including machine learning-guided design and patient-specific biomanufacturing to accelerate clinical translation. Multiscale metal-based nanocomposites, which bridge nanoscale innovations with macroscale functionality, are a revolutionary force in the field of biomedical engineering, providing personalized regenerative solutions for bone and joint diseases.

Limb salvage and complication management after (sub-) total humerus resection for primary malignant bone tumors in early childhood

Limb-salvage after (sub-) total humerus resection in skeletally immature patients, aged less than 10 years, remains the domain of individual case decisions due to a small number of affected patients. Seven children aged ≤ 10 years at the time of (sub-) total bone sarcoma resection of the humerus between 2018 and 2023 were included in this retrospective study. Limb salvage with an intact motor function of the lower arm was achieved in 100% of cases at a mean follow-up of 89.8 months. Reconstruction survival was 28.6%. 61.8% (n = 8/13) of complications necessitated revision operations (n = 7). Distal instability and dislocation (n = 5) was the most frequently observed complication, followed by periprosthetic infection (n = 2). However, both fixed hinge prostheses and hemiprostheses with a highly cancellous implant body led to stable reconstructions of the elbow joint. Arm lengthening (5 cm) was successful in two patients who underwent implantation of a growing prosthesis. Patients developed a handedness contralateral to the operated arm in this study. The mean MSTS and TESS scores were 16.6 and 51.5. Patients suffered from a limited range of motion in the glenohumeral joint, limited fine motor function and strength despite an intact innervation of the executing muscles. Salvage of even short segments of the distal humerus has a high potential to decrease complication rates, whenever oncologically feasible. The use of fixed-hinge total humerus (growing) prostheses and custom-made total humerus hemiprostheses with a highly cancellous implant body showed the most promising results in terms of complications and functional outcomes. Arm lengthening using growing prostheses - albeit of a mostly cosmetic value - is an option in the upper extremity whenever the soft tissue coverage of the implant is adequate.

Glutathione-Responsive Near-Infrared-II Fluorescence Probe for Early and Accurate Detection of In Situ and Metastatic Tumors

In situ and metastatic malignant tumors are primary diseases that threaten human life. Among all the metastases, liver metastasis is the most difficult to detect. As most imaging probes have high liver accumulation, it is difficult to distinguish tiny metastases from normal liver tissue with strong background signal. In this study, the design of a novel second near-infrared window (NIR-II) fluorescence probe for precise detection of carcinoma in situ and liver metastases is presented. The probe called Tg-RGD utilizes a commercially available cyanine dye IR-806 as the signaling moiety, a disulfide bond linker as the responsive moiety, an RGD-capped poly(ethylene glycol) (PEG) as the water soluble enhancer, and the tumor targeting moiety. Tg-RGD shows good glutathione (GSH) responsiveness and selectivity, where its NIR-II fluorescence intensity can enhance 50-fold after activation. In vivo study indicates that Tg-RGD shows much better imaging and targeting effects than Tg-PEG with a similar structure but without RGD moiety for both orthotopic breast cancer and osteosarcoma. Most importantly, Tg-RGD can detect tiny liver metastases with high signal-to-background ratio (3.2). Thus, this study reports a high-performance tumor-specific NIR-II fluorescence probe for in situ and tiny metastatic tumor detection, and may further broaden the applications into related tumor lesions.

Enhancing radiosensitivity of osteosarcoma by ITGB3 knockdown: a mechanism linked to enhanced osteogenic differentiation status through JNK/c-JUN/RUNX2 pathway activation

BACKGROUND

The prognosis of osteosarcoma has improved little over the past few decades, with radioresistance being a contributing factor. Effective radiosensitizing targets and novel mechanisms for treating osteosarcoma are urgently needed. Research on the impact of regulating differentiation levels on the radiosensitivity of malignant tumors is limited. This study aimed to explore the efficacy of ITGB3 as a novel radiosensitizing target in osteosarcoma and to explore whether the modulation of osteogenic differentiation plays a role in mediating the radiosensitizing effect.

METHODS

RNA sequencing was utilized to screen for potential targets that affect the radiosensitivity of osteosarcoma. In vitro assays examining cell viability, apoptosis, proliferation, migration, and invasion were conducted to verify the radiosensitizing effect of ITGB3-knockdown (KD). Furthermore, in vivo validation was performed by constructing mouse models with subcutaneous and orthotopic tibial tumors. Rescue experiments involving siRNAs and molecular inhibitors were performed to explore and validate the mechanisms through which ITGB3-KD exerts a radiosensitizing effect in vitro and in vivo. Additionally, osteogenic differentiation cultures of osteosarcoma cells were conducted as auxiliary validation for the radiosensitizing mechanism.

RESULTS

ITGB3-KD had a radiosensitizing effect on osteosarcoma in vitro by inhibiting cell viability, proliferation, migration, and invasion and promoting apoptosis. ITGB3-KD radiosensitized osteosarcoma in vivo in subcutaneous and orthotopic tibial tumor models. ITGB3-KD upregulated the JNK/c-JUN pathway, and rescue experiments with a JNK inhibitor revealed that the activation of this pathway was crucial for the upregulation of osteogenic markers such as RUNX2, OCN, and OPN, as well as for promoting apoptotic pathways. siRNA-based rescue experiments indicated that the upregulation of RUNX2 mediated the proapoptotic radiosensitizing effects of ITGB3-KD. Culture in osteogenic differentiation medium promoted osteosarcoma radiosensitization by enhancing the osteogenic differentiation status, working synergistically with ITGB3-KD.

CONCLUSIONS

Our findings indicate that ITGB3-KD enhances radiosensitivity in osteosarcoma by promoting osteogenic differentiation and apoptosis through activation of the JNK/c-JUN/RUNX2 pathway, identifying ITGB3 as a candidate therapeutic target and implicating JNK/c-JUN/RUNX2 signaling as a modulatory axis for improving the response to radiation of osteosarcoma.

Dual Regulation of Sprouty 4 Palmitoylation by ZDHHC7 and Palmitoyl-Protein Thioesterase 1: A Potential Therapeutic Strategy for Cisplatin-Resistant Osteosarcoma

Background: Osteosarcoma (OS) is a primary malignant bone tumor predominantly affecting adolescents. Chemotherapeutic agents, such as cisplatin, are commonly used in OS treatment; however, drug resistance markedly undermines treatment efficacy and contributes to reduced patient survival. The mechanisms underlying cisplatin resistance remain poorly understood. Recently, palmitoyl-protein thioesterase 1 (PPT1), a depalmitoylation enzyme, has attracted attention for its role in tumorigenesis and drug resistance. Investigating the mechanisms of PPT1 may offer new strategies to overcome resistance. Methods: This study analyzed multiple Gene Expression Omnibus datasets and utilized the OncoPredict tool to demonstrate the elevated expression of PPT1 in OS and its critical role in cisplatin resistance. By combining single-cell analysis with in vitro and in vivo experiments, we explored how PPT1 influences OS development through depalmitoylation and assessed the antitumor effects of the PPT1 inhibitor Ezurpimtrostat (GNS561), as well as its synergistic effects when combined with cisplatin. Results: We demonstrated that Sprouty 4 (SPRY4) undergoes a dynamic palmitoylation cycle regulated by zinc finger DHHC-type palmitoyl transferase 7 (ZDHHC7) and PPT1, which modulates mitogen-activated protein kinase (MAPK) signaling and subsequently affects tumor cell proliferation, migration, apoptosis, and drug resistance. Further validation confirmed the effectiveness of the PPT1 inhibitor GNS561 in overcoming cisplatin resistance. Notably, GNS561 exhibited a significant synergistic effect when used in combination with cisplatin, greatly enhancing the sensitivity of cisplatin-resistant cells. Conclusion: This study highlights the pivotal role of PPT1 in OS resistance mechanisms. PPT1 and ZDHHC7 regulate SPRY4 through a dynamic palmitoylation-depalmitoylation cycle that modulates MAPK signaling activation and contributes to OS cell proliferation, migration, and drug resistance. As a PPT1 inhibitor, GNS561 not only inhibits OS cell proliferation but also demonstrates synergistic effects with cisplatin, significantly enhancing cisplatin sensitivity in resistant cells and promoting apoptosis. Our findings offer a novel approach for targeting PPT1 in therapeutic strategies. GNS561 holds promise as an adjunctive therapy when combined with cisplatin, potentially overcoming resistance and improving efficacy, thereby enhancing the prognosis for OS patients. Future studies should further investigate the clinical potential of GNS561 and optimize OS treatment strategies.

An electrochemically charged nanoengineered bioelectronic immunosensing device for osteopontin detection in serum samples

Osteopontin (OPN) is a crucial biomarker for osteosarcoma, an aggressive bone cancer. Elevated levels of OPN are found in osteosarcoma tissues and blood samples, associated with tumor growth, metastasis, and poor prognosis. The present electrochemical voltammetric detection methods are mainly assisted by redox couple/chemical mediators in a measuring solution. However, in resource-confined settings, such a detection strategy undermines the potential for the development of precise and easy-to-use point-of-care bioelectronic devices. To simplify the detection method, herein, we present a reliable and straightforward clinically deployable immunosensor via engineering an electrochemically charged surface that does not require mediators in the solution phase. Such an electroactive surface offers a simplistic label-free detection of the protein OPN, requiring only the use of a buffer solution to obtain the signals. The electroactive immunosensor probe was engineered using electrodeposited gold, bimetallic FeGdHCF redox nanoparticles, and oxidized graphene nanoplatelets for immobilizing the OPN antibodies. Since the detection is precisely dependent on the redox-active electrode surface for obtaining analytical signals, this strategy was further designed into a miniaturized device cascade for the direct and on-site detection of OPN. The immunosensor probe showed a low LOD of 0.437 (±0.002) (RSD < 4.09%, n = 5) pg mL-1 and a wide LDR of 5 × 102 to 2 × 106 pg mL-1. It was applied to detect OPN in serum samples and was also evaluated for its selectivity against various molecules coexisting in real clinical samples and was found to be stable for a period of six weeks.

Cytotoxic lycorine alkaloids of the plant family Amaryllidaceae

The plant family Amaryllidaceae is embellished with a diverse array of antiproliferative alkaloid principles. Chief amongst these are the lycorine alkaloids, which have attracted considerable attention as potential anticancer drugs. This account tracks developments in the field with these substances encompassing the years 2015-2019. Twenty-nine compounds were screened against nearly eighty cancer cell lines representing seventeen different types of cancer. Submicromolar level activities were recorded against leukemia, myeloma and breast cancer cells. The response of lycorine (IC50 0.6 μM) to HL-60 myeloid leukemia cells was particularly striking. Promising activities were also documented from in vivo models of brain, lung, colon, prostate and breast cancer cells (in the 5-10 mg/kg/day dosage range). The screenings indicated these compounds to be efficacious without attendant detrimental effects towards control animals. Structure-activity relationship studies afforded useful insight to the elements of the anticancer pharmacophore, such as the necessity for the A-ring methylenedioxy and C-ring hydroxy functionalities. The mechanisms of action were intensively examined, with over twenty individual areas identified wherein such probes have been made. Of prominence here was the apoptosis-inducing abilities of lycorine against (amongst others) leukemia, pancreatic, bladder, liver and bone cancer cells, involving the modulation of key mediators such as caspase-3, p53, PARP, Bax and Bcl-2. Useful insights also emerged from docking studies undertaken with various cancer-related proteins, such as VEGF, HDAC, PI3Kα, c-Met kinase and EGFR. The lycorine alkaloids have proved to be highly versatile entities, readily embracing multiple facets of anticancer drug discovery.

Role of N6-methyladenosine methyltransferase component RBM15 in cancer progression and its therapeutic potential

Cancer ranks as a primary cause of mortality globally, and the study of its molecular markers and regulatory mechanisms holds paramount importance. N6-methyladenosine (m⁶A) represents the predominant modification in messenger RNA (mRNA), influencing key biological processes including RNA stability, splicing, and translation. The dynamic modulation of m⁶A modification is mediated by an array of enzymes comprising methyltransferases ("writers"), demethylases ("erasers"), and m⁶A-binding proteins ("readers").As a pivotal member of the m⁶A "writer" family, RNA binding motif protein 15 (RBM15) facilitates the recruitment of the methyltransferase complex (MTC) to mRNA, thus orchestrating the addition of m⁶A modifications. Although prior research has underscored the critical role of m⁶A in oncogenesis, the precise mechanisms through which RBM15 operates in cancer are yet to be elucidated. This study endeavors to elucidate the structural characteristics and functional roles of RBM15, investigate its potential regulatory mechanisms across diverse tumors, uncover its distinct functions in tumor genesis, progression, and metastasis, and evaluate the therapeutic potential of targeting RBM15 in cancer treatment.

The tumor microenvironment of metastatic osteosarcoma in the human and canine lung

Osteosarcoma is a rare but aggressive bone tumor that develops spontaneously in human and canine patients and most commonly metastasizes to the lung. The presence of lung metastases significantly decreases the survival rate of patients, with minimal benefit seen with available treatments. Canine osteosarcoma is clinically and molecularly similar to human osteosarcoma and develops approximately ten times more frequently than human osteosarcoma making dogs a promising natural model to study disease progression. The development of new therapies for pulmonary metastases requires an understanding of the interplay between tissue resident cells as well as recruited cell types and how those interactions impact seeding and progression within the new metastatic site. This review explores the tumor microenvironment surrounding pulmonary metastases and how current knowledge in canine and human patients can inform better treatments and outcomes for both populations.

Glypican-3 regulated epithelial mesenchymal transformation-related genes in osteosarcoma: based on comprehensive tumor microenvironment profiling

Introduction

Osteosarcoma (OS) is the most common primary bone malignancy, predominantly affecting children and adolescents. Current treatment approaches have limited efficacy, with a 5-year survival rate of approximately 60%. Epithelial-mesenchymal transition (EMT) plays a key role in the onset, progression, and metastasis of OS, potentially influencing patient prognosis.

Methods

We screened EMT-related genes from multiple transcriptomic datasets of OS and performed unsupervised consensus clustering of EMT-related gene sets. Key EMT-related genes were identified using weighted gene co-expression network analysis (WGCNA) and intersected with differentially expressed genes (DEGs) between OS and normal tissue samples. The least absolute shrinkage and selection operator (LASSO) algorithm was applied to screen candidate genes for developing a prognostic model. Single-cell RNA-Seq (scRNA-Seq) analysis was conducted on OS samples to identify cell populations expressing model genes. Functional validation was performed using si-GPC3 in the MG-63 cell line.

Results

The EMT-based prognostic model demonstrated strong predictive capacity across several validation cohorts. The model effectively predicted immune-related features and immunotherapy responses in high-risk and low-risk patient groups. Seven primary cell types were identified from scRNA-Seq data of OS samples, with the osteoblast population showing the highest proportion of cells positive for model genes. The OS_C3 subpopulation exhibited significantly higher scores and included nine gene modules associated with metabolism, structural integrity, proliferation, differentiation, adhesion, migration, immune responses, inflammatory reactions, and signal transduction. The model genes also demonstrated prognostic value across various cancer types. Knockdown of GPC3 in MG-63 cells resulted in decreased proliferation and migration ability.

Conclusion

This study provides new insights into the potential mechanisms of EMT in OS and its impact on the tumor immune microenvironment and response to immunotherapy. These findings may pave the way for novel personalized treatment strategies for OS patients.

Screening and identification Hub genes associated with immune cell infiltration and critical biomarkers in osteosarcoma

PURPOSE

Osteosarcoma (OS) exhibits limited immune cell infiltration that directly contributes to poor prognosis. This study sought to screen and identify pivotal biomarkers of OS immune infiltration and early diagnosis of OS.

METHODS

The immune cell infiltration profiles with transcriptome sequencing data from 88 OS samples were explored with CIBERSORT algorithm. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Protein-protein interaction (PPI) network analyses were applied to identify hub genes, with the expressions confirmed by dual immunofluorescence in 50 OS samples. The new biomarker gene HTRA1 were examined by immunohistochemistry and validated by the Immune score and immune gene expression profile analyses. The impact of HTRA1 on OS prognosis was verified by Least absolute shrinkage and selection operator (LASSO) regression analysis. The biological effect of HTRA1 was characterized in MG63 cells.

RESULT

CD8+ T cells, activated memory CD4+ T cells and plasma cells were positively correlated with the prognosis of OS. Hub genes CCL5, CXCL9, CXCL13, and HTRA1, exhibited positive correlation with the infiltration of both CD8+ T cells and CD4+ T cells. HTRA1 expression was reduced in osteosarcoma tissues, which was positively correlated with immune scores and the expressions of immune-related genes. High levels of HTRA1 were associated with favorable OS prognosis, and could negatively impacted MG63 malignant characteristics.

CONCLUSION

CCL5, CXCL9, CXCL13, and HTRA1 were OS hub genes positively correlate with CD8+ T cell and CD4+ T cell infiltrations. HTRA1 can serve as an underlying biomarker for the prognosis and immunotherapy of OS.

Osteosarcoma: Diagnosis, Treatment, and Emerging Opportunities

Osteosarcoma is the most common primary bone malignancy of childhood and adolescence. Despite advances in cures for many pediatric neoplasms, outcomes for osteosarcoma have not significantly changed for nearly 4 decades and treatment is similar for patients with both standard and higher risk disease. Recent progress has been demonstrated with evidence of activity of multitargeted tyrosine kinase inhibitors for patients with advanced osteosarcoma; further study is needed to evaluate their use for newly diagnosed patients. Novel approaches seek to exploit common cell surface antigens (LRRC15 and B7-H3) as well as aberrant DNA repair mechanisms and cell cycle checkpoints.

miR-486-3p Suppresses Osteosarcoma Proliferation and Migration by Targeting the SPRED1-MAPK/ERK Pathway

Osteosarcoma (OS) is a common malignancy of the bone that originates from stromal cell lines. One of the key cellular pathways extensively studied in OS is the mitogen-activated protein kinase (MAPK) pathway, particularly ERK1/2, whose activation is closely associated with tumor growth and metastasis. MicroRNA (miRNA)-based detection and targeted therapies offer promising new strategies for the treatment of OS. In this study, we investigated the role of miR‑486‑3p in the regulation of the ERK1/2 pathway in OS. We examined the expression level of miR‑486‑3p in the GEO dataset (GSE65071) and clinical samples, and analyzed its regulation of the target gene SPRED1 in OS cells and tumor-bearing mice. Downregulation of miR‑486‑3p was confirmed in OS tissues, with its expression decreasing in line with the progression of clinical stages. Furthermore, the exogenous introduction of a miR-486-3p mimic attenuated the malignant behavior of OS cells, inhibiting their proliferation, migration, and invasion. Bioinformatic analysis revealed that miR‑486‑3p directly targets SPRED1 in OS, leading to alterations in epithelial-to-mesenchymal transition (EMT) markers, including E-cadherin, N-cadherin, and Vimentin. Functional loss- and gain-of-function experiments confirmed that miR‑486‑3p directly targets SPRED1 and inactivates the ERK1/2 pathway in both OS cells and tumor-bearing mice. This review demonstrates that downregulation of miR-486-3p leads to increased SPRED1 expression, which activates the ERK1/2 pathway in OS. Targeting miR-486-3p and SPRED1 could offer potential therapeutic benefits.

Mechanistic Roles of Transcriptional Cyclin-Dependent Kinases in Oncogenesis: Implications for Cancer Therapy

Cyclin-dependent kinases (CDKs) are pivotal in regulating cell cycle progression and transcription, making them crucial targets in cancer research. The two types of CDKs that regulate different biological activities are transcription-associated CDKs (e.g., CDK7, 8, 9, 12, and 13) and cell cycle-associated CDKs (e.g., CDK1, 2, 4, and 6). One characteristic of cancer is the dysregulation of CDK activity, which results in unchecked cell division and tumor expansion. Targeting transcriptional CDKs, which control RNA polymerase II activity and gene expression essential for cancer cell survival, has shown promise as a therapeutic approach in recent research. While research into selective inhibitors for transcriptional CDKs is ongoing, inhibitors that target CDK4/6, such as palbociclib and ribociclib, have demonstrated encouraging outcomes in treating breast cancer. CDK7, CDK8, and CDK9 are desirable targets for therapy since they have shown oncogenic roles in a variety of cancer types, such as colorectal, ovarian, and breast malignancies. Even with significant advancements, creating selective inhibitors with negligible off-target effects is still difficult. This review highlights the need for more research to optimize therapeutic strategies and improve patient outcomes by giving a thorough overview of the non-transcriptional roles of CDKs in cancer biology, their therapeutic potential, and the difficulties in targeting these kinases for cancer treatment.

Therapeutic Efficacy Studies on the Monoterpenoid Hinokitiol in the Treatment of Different Types of Cancer

Hinokitiol (HK), a monoterpenoid that naturally occurs in plants belonging to the Cupressaceae family, possesses important biological activities, including an anticancer effect. This review summarizes its anticancer potential and draws possible molecular interventions. In addition, it evaluates the biopharmaceutical, toxicological properties, and clinical application of HK to establish its viability for future advancement as a dependable anticancer medication. The assessment is based on the most recent information available from various databases. Findings demonstrate that HK possesses substantial therapeutic advantages against diverse types of cancer (colon, cervical, breast, bone, endometrial, liver, prostate, oral, and skin) through various molecular mechanisms. HK induces oxidative stress, cytotoxicity, apoptosis, cell-cycle arrest at the G and S phases, and autophagy through modulation of phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR), p38/ERK/MAPK, nuclear factor kappa B, and c-Jun N-terminal kinase signaling pathways. Furthermore, this compound exhibits good oral bioavailability with excellent plasma clearance. Clinical uses of HK demonstrate therapeutic advantages without any significant negative effects. A thorough study of the pertinent data suggests that HK may serve as a viable candidate for developing novel cancer therapies. Consequently, more extensive studies are necessary to evaluate its cancer treatment efficacy, safety, and possible long-term hazards.

Identifying KDM5B as the synthetic lethal target of KMT2D-mutated osteosarcoma

Osteosarcoma (OS) is a malignant bone tumor that occurs commonly in adolescents or children, previous studies have shown its complex epigenetic signature. Histone methyltransferases KMT2D loss-of-function mutation is common in various types of human cancer. Here we revealed that KMT2D loss promotes malignant phenotypes in osteosarcoma. Based on the result of epigenetic inhibitor library screening we discovered that KDM5B inhibitors selectively killed KMT2D-deficient cells. Also, the knockdown of KDM5B by shRNA could reduce cell proliferation, migration and induce apoptosis in KMT2D-KO cells, while no similar appearance was observed in wild-type cells. Furthermore, we testified the efficiency and safety of KDM5B inhibition in patient-derived xenografts (PDX) mouse models driven by KMT2D low-expressing patients. These results demonstrated KDM5B as a synthetic lethal factor of KMT2D-loss mutation. Our findings suggest a novel therapeutic strategy for treating KMT2D mutated osteosarcoma by targeting KDM5B.

TME-responsive nanocomposite hydrogel with targeted capacity for enhanced synergistic chemoimmunotherapy of MYC-amplified osteosarcoma

The oncogene MYC is one of the most commonly activated oncogenic proteins in human tumors, with nearly one-fourth of osteosarcoma showing MYC amplification and exhibiting the worst clinical outcomes. The clinical efficacy of single radiotherapy, chemotherapy, and immunotherapy for such osteosarcoma is poor, and the dysregulation of MYC amplification and immune-suppressive tumor microenvironment (TME) may be potential causes of anti-tumor failure. To address the above issues, we developed an injectable TME-responsive nanocomposite hydrogel to simultaneously deliver an effective MYC inhibitor (NHWD-870) and IL11Rα-targeted liposomes containing cisplatin-loaded MnO2 (Cis/Mn@Lipo-IL11). After in situ administration, NHWD-870 effectively degrades MYC and downregulates CCL2 and IL13 cytokines to trigger M1 type activation of macrophages. Meanwhile, targeted delivery of Cis/Mn@Lipo-IL11 reacts with excess intratumoral GSH to generate Mn2+ and thus inducing excess active oxygen species (ROS) production through Fenton-like reaction, along with cisplatin, thereby inducing immunogenic cell death (ICD) to promote dendritic cell maturation. Through synergistic regulation of MYC and ICD levels, the immune microenvironment was reshaped to enhance immune infiltration. In the osteosarcoma-bearing model, the nanocomposite hydrogel significantly enhanced tumor T cell infiltration, induced effective anti-tumor immunity and attenuated lung metastasis. Therefore, our results reveal a powerful strategy for targeted combination therapy of MYC-amplified osteosarcoma.

pH-responsive paclitaxel prodrug encapsulated in a polypeptide-chitosan polymer delivery system for osteosarcoma treatment

Osteosarcoma, a highly invasive and metastatic primary bone malignancy, remains a significant clinical challenge due to the limited improvement in overall survival despite advances in treatment strategies. This highlights the urgent need for the development of more effective therapeutic options. In response, we have developed a novel paclitaxel (PTX)-loaded nanodrug system, PLGA-CS-1@PTX, by incorporating a synthesized epoxy-tetrapeptide derivative (compound 1) with poly(lactic-co-glycolic acid) (PLGA) and chitosan (CS), forming the PLGA-CS-1 composite system. The system was thoroughly characterized for its physicochemical properties, including morphology, particle size, and in vitro release behavior. Scanning electron microscopy (SEM) confirmed the nanostructure of the particles, with particle sizes around 170 nm and a narrow PDI (<0.15), indicating a uniform distribution. In vitro release studies showed a pH-responsive release profile, with 84.8 % of PTX released at pH 5.4 after 65 h of incubation, compared to 68.1 % at pH 6.4 and 14.8 % at pH 7.4, demonstrating good drug release control in acidic environments. Biological assays demonstrated significant inhibition of osteosarcoma cell proliferation in both HOS and U2OS cell lines, with a dose-dependent reduction in SPICE1 expression, suggesting that PLGA-CS-1@PTX can effectively suppress the proliferative activity of osteosarcoma cells by modulating SPICE1 levels. The hydrophobic segment of the peptide enhanced the drug loading capacity and minimized side effects, improving the overall safety profile of the system. This composite system effectively integrates the strengths of each component, offering a promising, safe, and efficient strategy for osteosarcoma treatment with great potential for clinical application.

Cardamom synergizes with cisplatin against human osteosarcoma cells by mTOR-mediated autophagy

Cisplatin (DDP), a frontline chemotherapeutic agent in osteosarcoma (OS) treatment, is frequently paired with other compounds to enhance its therapeutic potency. Cardamom (CAR), a natural flavonoid, exhibits significant inhibitory effects on human OS cells while minimizing toxic side effects. In this study, we combined CAR and DDP to treat OS, revealing that the DDP/CAR combination synergistically inhibits the growth of human OS cells in vitro and in vivo. Network pharmacological analysis indicated that mammalian target of rapamycin (mTOR) may be an important cross-target for DDP/CAR combination. Notably, this combined treatment significantly reduced mTOR phosphorylation and elevated autophagy levels within OS cells. At the mechanistic level, the DDP/CAR regimen enhanced apoptosis and compromised the viability of OS cells by triggering autophagy. This impact was attenuated by the use of the mTOR activator MHY and the autophagy inhibitor hydroxychloroquine (HCQ). Furthermore, in DDP-resistant cell lines, CAR was able to mitigate DDP resistance by bolstering autophagy levels. In general, our results suggest that CAR bolstering autophagy levels DDP against OS cells through the induction of mTOR-mediated autophagy.

Microfabricated Organ-Specific Models of Tumor Microenvironments

Despite the advances in detection, diagnosis, and treatments, cancer remains a lethal disease, claiming the lives of more than 600,000 people in the United States alone in 2024. To accelerate the development of new therapeutic strategies with improved responses, significant efforts have been made to develop microfabricated in vitro models of tumor microenvironments (TMEs) that address the limitations of animal-based cancer models. These models incorporate several advanced tissue engineering techniques to better reflect the organ- and patient-specific TMEs. Additionally, microfabricated models integrated with next-generation single-cell omics technologies provide unprecedented insights into patient's cellular and molecular heterogeneity and complexity. This review provides an overview of the recent understanding of cancer development and outlines the key TME elements that can be captured in microfabricated models to enhance their physiological relevance. We highlight the recent advances in microfabricated cancer models that reflect the unique characteristics of their organs of origin or sites of dissemination.

Vitamin B12 as a novel USP3 deubiquitinase inhibitor suppresses cell proliferation and growth in osteosarcoma

Targeting oncogenic ubiquitin-specific proteases (USPs) has been regarded as a potential useful strategy for cancer treatment. In the current study, we aimed to screen candidate small molecule target oncogenic USPs in osteosarcoma. Initially, analysis of public datasets revealed that USP3 is significantly upregulated in osteosarcoma tissues. Functional studies further demonstrated that USP3 promotes osteosarcoma cell proliferation and tumor growth both in vitro and in vivo. Through structure-based virtual screening, we identified Vitamin B12 as a potential USP3 inhibitor. Biochemical assays confirmed that Vitamin B12 effectively suppresses USP3 activity at a level comparable to PR619, a broad-spectrum deubiquitinase inhibitor. Furthermore, Vitamin B12 mitigates the oncogenic effects of USP3 in osteosarcoma by inhibiting its deubiquitinase activity. In conclusion, our findings offer new insights into the role of USP3 in osteosarcoma and underscore the potential of Vitamin B12 as a promising therapeutic agent.

Epigenetic Inactivation of RIPK3-Dependent Necroptosis Augments Cisplatin Chemoresistance in Human Osteosarcoma

Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents. Unfortunately, drug resistance limits the efficacy of chemotherapeutic treatment and compromises therapeutic outcomes in a substantial proportion of cases. Aberrant CpG island methylation-associated transcriptional silencing contributes to chemoresistance in pediatric solid tumors. Here, using whole-genome DNA methylation screening on 16 human primary OS specimens, we identify receptor interacting protein kinase-3 (RIPK3), a molecular regulator of the necroptosis programmed cell death pathway, as a gene target of aberrant CpG methylation and demonstrate its role in human OS chemoresistance. We validated these findings via enforced expression and DsiRNA silencing, and evaluated the role of RIPK3 in cisplatin chemosensitivity and necroptosis activation through MLKL phosphorylation. We found that CpG island methylation results in RIPK3 silencing in primary human OS samples and cell lines. Enforced RIPK3 expression significantly enhanced cisplatin cytotoxicity in OS cells and DsiRNA knockdown reversed the cisplatin-sensitive phenotype. In cells with enforced RIPK3 expression, cisplatin treatment significantly increased phosphorylation of both RIPK3 and its target, MLKL, indicative of induction of necroptosis. Here, we identify RIPK3 as an important mediator of chemoresistance in OS and a potential pharmacologic target to improve chemotherapy efficacy in drug-resistant tumors.

Prognostic nomogram for overall survival in pediatric osteosarcoma with pulmonary metastases: a SEER database analysis

Background

Pulmonary metastasis (PM) is the most common site of distant metastasis in osteosarcoma (OS), particularly in pediatric cases, which are associated with poor prognosis. However, limited research has focused on identifying prognostic factors (PFs) for pediatric osteosarcoma with pulmonary metastasis (POPM). This study aims to identify clinical features and PFs of POPM and develop a validated nomogram to predict overall survival in POPM patients.

Methods

A retrospective analysis was conducted using OS cases from the Surveillance, Epidemiology, and End Results (SEER) database (2010-2021). Clinical characteristics were compared between patients with and without PM. PFs were identified using Least Absolute Shrinkage and Selection Operator (LASSO) regression and evaluated through Kaplan-Meier analysis. Patients were divided into training (N = 148) and validation (N = 64) cohorts. Independent PFs were determined via Cox regression to construct a prognostic nomogram, which was assessed using the concordance index (C-index), the area under the receiver operating characteristic curve (AUC-ROC), and calibration plots. Decision curve analysis (DCA) was used to evaluate clinical applicability.

Results

LASSO regression identified key PFs: AJCC stage, T stage, median household income, systemic therapy, and time from diagnosis to treatment. Among these, all except T stage were validated as independent PFs via Cox regression. The nomogram demonstrated strong predictive accuracy with C-index values of 0.68 (training) and 0.71 (validation). AUC values for 1-, 3-, and 5-year survival were 0.786, 0.709, and 0.711 in the training cohort and 0.780, 0.760, and 0.776 in the validation cohort. Calibration plots showed excellent concordance between predicted and actual survival, and DCA confirmed the nomogram's clinical relevance.

Conclusion

AJCC stage, median household income, systemic therapy, and time from diagnosis to treatment are significant PFs for POPM survival. The validated nomogram provides a valuable tool for personalized prognostic assessment and treatment decision-making in clinical practice.

KPNA2 promotes osteosarcoma progression by regulating the alternative splicing of DDX3X mediated by YBX1

Osteosarcoma (OS) is a rapidly progressive primary malignant bone tumor that occurs in children and adolescents aged between 15 and 19 years and adults aged over 60 years. As alternative splicing (AS) changes caused by abnormal splicing factors contribute to tumor progression, gene expression and AS analyses were performed on 44 osteosarcoma patients to create a genome-wide co-expression network of RNA-binding proteins (RBPs), AS events, and AS genes. A gain- or loss-of-function osteosarcoma cell model was established, and an interactive network analysis and enrichment analysis were performed. Karyopherin Subunit Alpha 2 (KPNA2) negatively correlated with patient survival. KPNA2 transports splicing factor Y-box Binding Protein 1 (YBX1) into the nucleus and YBX1 accelerates the degradation of the ATP-dependent RNA helicase DDX3X (DDX3X) through the nonsense-mediated decay (NMD) pathway to promote intron retention of the DDX3X gene, thus reducing DDX3X protein levels. KPNA2/YBX1 axis regulates the stability of DDX3X mRNA and cell cycle progression. KPNA2/YBX1/DDX3X axis might be potential targets for inhibiting disease progression and improving OS patient survival. It integrates AS control of DDX3X into the progression of OS and represents a potential prognostic biomarker and therapeutic target for OS therapy.

NETs-related genes predict prognosis and are correlated with the immune microenvironment in osteosarcoma

Background

Osteosarcoma is the most common primary bone tumor. It has a high rate of early metastasis, and its treatment is one of the most challenging topics in the bone tumor field. Recent studies have shown that neutrophil extracellular traps play an important role in tumor metastasis and may provide new horizons for exploring metastasis in osteosarcoma.

Methods

OS data were downloaded from the TARGET database and Gene Expression Omnibus datasets. Univariate Cox regression was conducted to assess NETRGs. Patients were subsequently categorized into high- and low-risk groups on the basis of risk score values derived from multivariate Cox analysis, and prognostic models were established. The immune infiltration of relevant genes and drug sensitivity of key genes were also analyzed.

Results

A total of 15 NETs-related genes associated with osteosarcoma metastases were identified. Among them, a total of 4 genes were related to prognosis, namely, MAPK1, CFH, ATG7 and DDIT4, and a prognostic model based on these 4 genes was established. The prognosis was worse in the high-risk group, whose areas under the ROC curves (AUCs) were 0.857, 0.779, and 0.689 at 1, 3, and 5 years, respectively. The key genes were subsequently found to be associated with the infiltration of 20 types of immune cells. Finally, the small-molecule drug toxin c 10, an approximately 6700 mw protein, may target key genes. Finally, ATG7 was validated at the histological level by combining the results of the validation group dataset analysis.

Conclusions

A risk model based on 4 NETRDEGs is a reliable prognostic predictor for OS patients, and CFH and ATG7 may serve as a new diagnostic and therapeutic target.

Prognostic significance of T cells and NK cells in osteosarcoma: a dual-center retrospective study

BACKGROUND

There is no study on the relationship between peripheral blood different lymphocyte subtypes and the prognosis of osteosarcoma (OS). Therefore, this study aims to investigate the predictive value of T cells and natural killer (NK) cells for the prognosis of OS patients.

METHODS

This study retrospectively analyzed the clinical data and preliminary laboratory indicators of patients with OS admitted from dual-center between January 2014 and January 2021. The receiver operating characteristic (ROC) curve was employed to determine optimal cutoff values for different lymphocyte subtypes, with T cells, NK cells, and B lymphocytes subsequently stratified into high- and low-proportion groups based on their respective optimal cutoff values. Kaplan-Meier curve was employed to analyze the impact of different lymphocyte on survival time and status. Univariate and multivariate Cox analyses were performed on clinical and laboratory indicators to identify independent prognostic factors influencing the prognosis of OS patients.

RESULTS

After screening 277 patients with OS, a total of 106 patients were eligible for this study. The median follow-up time was 36.00 months. At the last follow-up, patients were categorized as having a good prognosis if they survived or a poor prognosis if they died: good prognosis (n = 48) and poor prognosis (n = 58). Kaplan-Meier curve revealed that patients with a high proportion of T (Median overall survival: 41 months vs. 32 months, P = 0.007) and NK (Median overall survival: 44 months vs. 32 months, P = 0.004) cells had a better prognosis compared to those with a low proportion. Univariate analysis indicated that age, body mass index (BMI), C-reactive protein (CRP), tumor size, Enneking stage, surgical method, and the proportions of T, NK, and B cells were associated with the prognosis of OS patients (P < 0.05). Multivariate analysis indicated that Enneking stage (II vs. I, HR = 12.543, P = 0.015; III vs. I, HR = 29.078, P = 0.001), and the proportions of T and NK cells (HR = 0.466, P = 0.048; HR = 0.497, P = 0.029) were independent factors influencing the prognosis of OS patients (P < 0.05).

CONCLUSION

The proportions of T and NK cells may serve as efficient and practical prognostic indicators for OS patients, with higher proportions often associated with a better prognosis.

Synergistic chemo-immunotherapy for osteosarcoma via a pH-responsive multi-component nanoparticle system

Introduction

Osteosarcoma (OS) is the most common primary malignant bone tumor in pediatric populations. Its treatment is complicated by chemotherapy-induced toxicity and limited induction of immunogenic cell death (ICD).

Methods

To address these challenges, we developed a pH-responsive, multi-component nanoparticle system designed to co-deliver doxorubicin (DOX), monophosphoryl lipid A (MPLA), and a PD-1/PD-L1-targeting peptide, integrated with the immune-modulating polymer PEG-PC7A. The system was optimized using both one-factor-at-a-time (OFAT) and Box-Behnken design (BBD).

Results

The optimized nanoparticles had a hydrodynamic size of 110 nm, high encapsulation efficiency (97.15%), and pH-sensitive drug release (91% at pH 6.5). In vitro studies showed enhanced ICD markers, including calreticulin exposure and ATP/HMGB1 release, aswell as synergistic dendritic cell maturation via dual STING/TLR4 pathway activation. In an orthotopic LM8 osteosarcoma model, the nanoparticles significantly suppressed tumor growth, promoted cytotoxic T lymphocyte infiltration, reduced regulatory T cells, and established long-term immune memory.

Discussion

The combination of ICD induction, innate immune activation, and checkpoint blockade reprogrammed the tumor microenvironment, amplifying anti-tumor immune responses. These results demonstrate the potential of this multifunctional nanoparticle platform as an effective immunochemotherapeutic strategy for osteosarcoma, offering enhanced therapeutic efficacy and reduced systemic toxicity.

Multi-omics analysis of copper metabolism-related molecular subtypes and risk stratification for osteosarcoma

BACKGROUND

As the most common primary malignant bone tumor, further investigation into risk stratification for osteosarcoma (OS) prognosis is of significant clinical importance. Copper is essential for bone metabolism; however, its specific role in OS remains unclear.

METHODS

The expression characteristics of copper metabolism related genes (CORGs) in OS were revealed by single cell sequencing. Prognosis-associated CORGs were identified, and a CORG-related scoring system and risk model were established using bioinformatics approaches, including univariate and multivariate Cox regression analyses and LASSO analysis. We further analyzed immune microenvironment infiltration, molecular subtypes and clinicopathological characteristics. The impact of selected CORG with high-risk coefficient on OS cells was tested by qRT-PCR, western blot, siRNA, colony formation analysis and Transwell in vitro.

RESULTS

We successfully developed an OS scoring system related to copper metabolism and validated its independent prognostic value in patients with OS. The potential clinical value of CORG scoring system was analyzed. APOA4 was selected for in vitro experiments and its effect on the proliferation and invasion ability of OS cells was verified.

CONCLUSION

We established a copper metabolism-related scoring system to effectively stratify the risk of OS patients. Our results provide a new basis for the role of copper metabolism in OS and provide new potential targets for the treatment of OS.

Injectable and adhesive MgO2-potentiated hydrogel with sequential tumor synergistic therapy and osteogenesis for challenging postsurgical osteosarcoma treatment

The clinical treatment of osteosarcoma faces great challenges of residual tumor cells leading to tumor recurrence and irregular bone defects difficult to repair after surgery removal of the primary tumor tissue. We developed an injectable and in-situ cross-linkable hydrogel (named MOG hydrogel) using MgO2 nanoparticles and dopamine-conjugated gelatin as main components. MgO2 was rationally designed as a multifunctional active ingredient to mediate in situ gelation, tumor therapy, and bone repair sequentially. The 10MOG (with 10 mg/mL MgO2 content) showed excellent gel stability, injectability, shape adaptability, tissue adhesion, and rapid hemostatic ability. Importantly, 10MOG exhibited ideal sequential H2O2 and Mg2+ release property. The released H2O2 synergized with photothermal therapy for enhanced tumor recurrence suppression, and the sustainable Mg2+ release efficiently promoted bone regeneration. The MOG hydrogel, possessing excellent on-demand antitumor and osteogenic capabilities in vitro and in vivo, exhibited tremendous potential in the clinical application for challenging postsurgical osteosarcoma treatment.

Lipid metabolic reprogramming and associated ferroptosis in osteosarcoma: From molecular mechanisms to potential targets

Osteosarcoma is a common bone tumor in adolescents, which is characterized by lipid metabolism disorders and plays a key role in tumorigenesis and disease progression. Ferroptosis is an iron-dependent form of programmed cell death associated with lipid peroxidation. This review provides an in-depth analysis of the complex relationship between lipid metabolic reprogramming and associated ferroptosis in OS from the perspective of metabolic enzymes and metabolites. We discussed the molecular basis of lipid uptake, synthesis, storage, lipolysis, and the tumor microenvironment, as well as their significance in OS development. Key enzymes such as adenosine triphosphate-citrate lyase (ACLY), acetyl-CoA synthetase 2 (ACSS2), fatty acid synthase (FASN) and stearoyl-CoA desaturase-1 (SCD1) are overexpressed in OS and associated with poor prognosis. Based on specific changes in metabolic processes, this review highlights potential therapeutic targets in the lipid metabolism and ferroptosis pathways, and in particular the HMG-CoA reductase inhibitor simvastatin has shown potential in inducing apoptosis and inhibiting OS metastasis. Targeting these pathways provides new strategies for the treatment of OS. However, challenges such as the complexity of drug development and metabolic interactions must be overcome. A comprehensive understanding of the interplay between dysregulation of lipid metabolism and ferroptosis is essential for the development of innovative and effective therapies for OS, with the ultimate goal of improving patient outcomes.

Exosomes derived from FN14-overexpressing BMSCs activate the NF-κB signaling pathway to induce PANoptosis in osteosarcoma

Despite advances in treatment, the prognosis of osteosarcoma (OS) patients is unsatisfactory, and searching for possible targets is substantial. Fibroblast growth factor inducible type 14 (FN14), a plasma membrane protein, is involved in wound healing, angiogenesis, proliferation, apoptosis, and inflammation. However, its implication in OS development and progression has not been completely characterized. Herein, we explored the cell-to-cell communication of bone marrow mesenchymal stem cells (BMSCs) and OS cells mediated by FN14 in the tumor microenvironment of OS. To assess the interplay between FN14 expression levels and patient survival, FN14 expression was measured in both normal and OS tissues. The FN14 overexpressing BMSCs (OE) were constructed using lentivirus, and exosomes (EXO) were extracted. The uptake of FN14-containing EXO by OS cells was analyzed via flow cytometry and in vivo fluorescence imaging. In addition, high-throughput sequencing was performed to analyze the mechanisms by which EXO inhibits OS cell growth. Finally, the therapeutic effect of OE-EXO was evaluated in a mouse model of OS xenografts. The results showcased reduced FN14 expression in human and mouse OS tissues, suggesting its role may be involved in the malignant progression of OS. The FN14 expression was higher in BMSCs relative to OS cells, and FN14 was secreted and excreted by EXO. The OS cell progression was suppressed after the uptake of FN14-derived EXO from BMSCs. In addition, RNA sequencing revealed that FN14 in EXO activated NF-κB signaling, triggering PANoptosis in OS cells. In vivo, OE-EXO injection inhibited tumor growth in OS xenografts and significantly improved the long-term survival of mice. Our findings suggest that FN14 carried by EXO from BMSCs activates the NF-κB pathway to trigger PANoptosis in OS cells, providing a potential therapeutic strategy to inhibit OS progression.

Surgical Margins and Oncologic Outcomes Following Wedge Resection of Pulmonary Metastases in Pediatric and Young Adult Patients with Sarcoma

INTRODUCTION

Children and young adults diagnosed with sarcoma often present with pulmonary metastases requiring wedge resection. It is important to balance the risk of pulmonary recurrence against the desire to limit resection of benign parenchyma. This study aims to determine the impact of resection margins on survival and recurrence among pediatric and young adult sarcoma patients.

PATIENTS AND METHODS

We conducted a retrospective cohort study of patients ages 25 years and younger with primary or recurrent osteogenic, Ewing's, or soft tissue sarcoma who underwent pulmonary metastasectomy (2006-2022). Margins were categorized as > 1 mm, ≥ 5 mm, or ≥ 10 mm length. Two-year overall survival (OS), disease-free survival (DFS), and regional disease-free survival, consisting of pulmonary recurrence following metastasectomy, were analyzed using the Kaplan-Meier method. Cox analysis utilized patient, tumor, and treatment factors to predict risk of death and/or recurrence.

RESULTS

In total, 122 patients were identified for analysis. The median number of wedge resections was 3.5, median nodule size was 12.5 mm, and median margin length was 3 mm. A 5-mm margin was associated with improvements in DFS and regional-DFS (10.6% vs. 29.7%, p = 0.01 and 10.7% versus 31.1%, p = 0.005, respectively). On Cox analysis, margin length was not associated with OS (p > 0.05); however, 5 mm (HR 0.46, p = 0.005) and 10-mm margins (HR 0.39, p = 0.04) were associated with improvements in regional DFS. Margin length was not associated with development of postoperative complications (p = 0.20).

CONCLUSIONS

Among pediatric and young adult sarcoma patients with pulmonary metastases, increased margin length was associated with decreasing risk of local recurrence but not the development of postoperative complications.

Macrophage and osteosarcoma cell crosstalk is dependent on oxygen tension and 3D culture

Osteosarcoma (OS), the most common form of primary bone cancer in young adults, has had no improvements in clinical outcomes in 50 years. This highlights a critical need to advance mechanistic understanding of OS to further therapeutic discovery, which will only be possible with accurate models of the disease. Compared to traditional monolayer studies and preclinical models, in vitro models that better replicate the three-dimensional (3D) bone marrow microenvironment will facilitate methodical investigations of the events and factors that drive OS progression. Herein, we use fibrin-alginate interpenetrating network (FA IPN) hydrogels to model the hematological bone marrow environment. We interrogated the effects of oxygen tension, 3D culture, and macrophage phenotype on OS behavior and specifically examine the immunomodulatory crosstalk between OS and macrophages. We observe that OS is more sensitive to oxygen tension when cultured in 3D. Specifically, both highly and less metastatic OS exhibit decreased changes in DNA content over time in 3D, but then demonstrate diverging behaviors in heterotypic culture with macrophages. OS response to macrophages differs as a function of metastatic potential, where highly metastatic OS shows increased immunosuppression that varies with oxygen tension but relies on direct coculture conditions. To our knowledge, this is among the first work to report the effects of 3D culture on the interplay between OS and macrophages in a coculture microenvironment. Together, these data introduce FA IPNs as a promising platform for cancer research and emphasize the importance of novel models for the mechanistic study of OS.

The origin and polarization of Macrophages and their role in the formation of the Pre-Metastatic niche in osteosarcoma

Osteosarcoma, a primary malignant bone tumor commonly found in adolescents, is highly aggressive, with a high rate of disability and mortality. It has a profound negative impact on both the physical and psychological well-being of patients. The standard treatment approach, comprising surgery and chemotherapy, has seen little improvement in patient outcomes over the past several decades. Once relapse or metastasis occurs, prognosis worsens significantly. Therefore, there is an urgent need to explore new therapeutic approaches. In recent years, the successful application of immunotherapy in certain cancers has demonstrated its potential in the field of cancer treatment. Macrophages are the predominant components of the immune microenvironment in osteosarcoma and represent critical targets for immunotherapy. Macrophages exhibit dual characteristics; while they play a key role in maintaining tumor-promoting properties within the microenvironment, such as inflammation, angiogenesis, and immune suppression, they also possess antitumor potential as part of the innate immune system. A deeper understanding of macrophages and their relationship with osteosarcoma is essential for the development of novel therapeutic strategies.

Role of exosomes in diagnosis, prognostication, and treatment of pediatric solid tumors

Cancer is the second leading cause of death in children, and solid tumors make up 30% of childhood cancers. Molecular profiling of pediatric solid tumors allows a personalized approach to therapy, but this approach mostly relies on surgical biopsy, which is invasive and carries the risk of complications. Liquid biopsy serves as a reliable alternative and a minimally invasive tool for diagnosing, prognosticating, and residual disease monitoring in childhood cancers. This review outlines the potential of exosomes as informative liquid biopsies in pediatric solid tumors. Studies highlighting the potential applications and clinical utility of exosomes and their molecular constituents as prognosticators and therapies in common childhood solid tumors, including neuroblastoma, medulloblastoma, sarcoma, and hepatoblastoma, have been overviewed. We also discuss the limitations and technical challenges of utilizing exosomes for pediatric solid tumors.

Review of the role and potential clinical value of m6A methylation modifications in the biological process of osteosarcoma

Osteosarcoma (OS), an aggressive bone tumor, is a substantial threat to the quality of life and survival of affected individuals. Despite recent improvements in OS therapies, the considerable variability and chemotherapy resistance of this cancer necessitate continuous research to discover new treatment targets and biomarkers. Recent epigenetic advances highlight the crucial role of N6-methyladenosine (m6A) methylation in cancer. In OS, m6A methylation has been demonstrated to be a pivotal component in the pathogenesis. This review introduces new findings regarding the association between m6A methylation regulators and OS, and summarizes the potential clinical applications of OS and m6A methylation regulators, including the role of m6A methylation in OS proliferation, growth, apoptosis, and cell migration, invasion, and metastasis; relationship between m6A methylation and OS chemotherapy resistance; and relationship between m6A methylation and OS prognosis. Our review had certain limitations. The interaction between m6A methylation regulators and other oncogenic factors, such as lncRNAs and ncRNAs, is not fully understood. We hope that these potential methods will be translated into clinical applications and effective treatment.

The role of cryptochrome (CRY) in cancer: molecular mechanisms and Clock-based therapeutic strategies

The circadian rhythm is a phenomenon in which physiological, behavioral, and biochemical processes within an organism naturally fluctuate over a period of approximately 24 hours. This phenomenon is ubiquitous in living organisms. Disruption of circadian rhythms in mammals leads to different diseases, such as cancer, and neurodegenerative and metabolic disorders. In specific tissues, numerous genes have been found to have circadian oscillations, suggesting a broad role for rhythm genes in the regulation of gene expression. This review systematically summarizes the role of cryptochromes (CRYs) in the initiation and progression of different types of cancer and discusses the relationships between Clock genes and the tumor microenvironment (TME), as well as clock-based therapeutic strategies.

Design, synthesis, and biological evaluation of Flavokavain B derivatives as potent TRF2 inhibitors for the treatment of Osteosarcoma

Telomere repeat-binding factor 2 (TRF2) is a crucial component of the shelterin complex, commonly overexpressed in osteosarcoma (OS) and positively correlated with its progression. To date, effective TRF2 inhibitors for in vivo applications remain limited. In this study, a series of Flavokavain B derivatives were designed and synthesized, and their TRF2 inhibition and antitumor activity were evaluated. Among the tested compounds, the active compound F2 showed remarkable inhibition of TRF2 expression, along with potent antiproliferative activity in U2OS and MG63 cells, with IC50 values of 5.28 μM and 1.52 μM, respectively. Moreover, F2 significantly suppressed OS cell proliferation and induced apoptosis by accelerating telomere shortening and loss due to TRF2 inhibition. Mechanically, F2 selectively inhibited TRF2 protein expression and telomeric localization by directly binding to the TRF2TRFH domain. Furthermore, F2 demonstrated strong antitumor efficacy with minimal toxicity in an MG63-derived xenograft mouse model. These findings demonstrate that F2 is a promising drug candidate for the treatment of osteosarcoma.

Vascularized fibular epiphyseal transfer for biological reconstruction of bone defects following resection in children with proximal humeral sarcoma

BACKGROUND

The functional reconstruction of bone defects following resection of proximal humerus tumors in children poses a significant challenge. This study utilized vascularized fibular epiphyseal transfer for proximal humerus reconstruction to evaluate the outcome, complications, and survival rates.

METHODS

In this study, we conducted a retrospective analysis of 13 pediatric patients who underwent vascularized fibular epiphyseal transfer for biological reconstruction following oncologic resection of the proximal humerus between 2019 and 2021. All patients received adequate preoperative preparation and evaluation, and complications were meticulously recorded. Regular functional follow-ups and imaging evaluations were performed.

RESULTS

A total of 13 patients with an average age of 9.8 years were included in this study. The average length of the humerus defect after surgical resection was 13.7 cm (9.4-17.8 cm). Delayed wound healing was observed in 2 patients, and one patient experienced brief common peroneal nerve palsy. There were 3 cases of graft fracture, all of which occurred within 1 year after operation. These cases were successfully managed through the application of draping plaster or brace fixation. The mean follow-up period was 39.8 months (ranging from 19 to 57 months). The mean Musculoskeletal Tumor Society (MSTS) score was 21.5 (18-24). All patients reported no persistent pain.

CONCLUSION

In conclusion, we assert that vascularized fibular epiphyseal transfer provides a reliable and promising option for reconstruction in pediatric patients undergoing proximal humerus tumor resection surgery. Graft fractures were the most prevalent complication, emphasizing the importance of cautionary measures to prevent falls or trauma. However, further validation through increased case numbers and extended follow-up periods is necessary.

Domain adaptive detection framework for multi-center bone tumor detection on radiographs

Automatic bone tumor detection on radiographs is crucial for reducing mortality from bone cancer. However, the performance of the detection methods may be considerably affected when deployed to bone tumor data in a distinct domain, which could be attributed to the differences in the imaging process and can be solved by training with a large amount of annotated data. However, these data are difficult to obtain in clinical practice. To address this challenge, we propose a domain-adaptive (DA) detection framework to effectively bridge the domain gap of bone tumor radiographs across centers, consisting of four parts: a multilevel feature alignment module (MFAM) for image-level alignment, Wasserstein distance critic (WDC) for quantization of feature distance, instance feature alignment module (IFAM) for instance-level alignment, and consistency regularization module (CRM), which maintains the consistency between the domain predictions of MFAM and IFAM. The experimental results indicated that our framework can improve average precision (AP) with an intersection over union threshold of 0.2 (AP@20) on the source and target domain test sets by 1 % and 8.9 %, respectively. Moreover, we designed a domain discriminator with an attention mechanism to improve the efficiency and performance of the domain-adaptative bone tumor detection model, which further improved the AP@20 on the source and target domain test sets by 2 % and 10.7 %, respectively. The proposed DA model is expected to bridge the domain gap and address the generalization problem across multiple centers.

O-GlcNAcylation: Sagacious Orchestrator of Bone-, Joint-, and Spine-Related Diseases

O-linked beta-N-acetylglucosamine glycosylation (O-GlcNAcylation), a post-translational modification of proteins, occurs in multiple physiological and pathological processes. Despite comprehensive study of protein modifications, such as phosphorylation, acetylation, and ubiquitination in musculoskeletal diseases, the role of O-GlcNAcylation in this field has been largely overlooked. However, in recent years, several studies have initially elucidated the biological mechanisms through which O-GlcNAcylation regulates the development and progress of musculoskeletal diseases, including osteoarthritis, osteoporosis, osteosarcoma, and intervertebral disc degeneration. This review aims to systematically and comprehensively summarize the existing evidence, sketching the contours of the underlying mechanisms and related signaling pathways, discussing the limitations and controversies, and providing guidance for future studies on the role of O-GlcNAcylation modifications in musculoskeletal diseases.

Ziyuglycoside II suppressed the progression of osteosarcoma by coordinating estrogen-related receptor gamma and p53 signaling pathway

Osteosarcoma (OS) is the most prevalent primary malignant bone tumor affecting children and adolescents. Despite ongoing research efforts, the 5-year survival rate has remained stagnant for many years, highlighting the critical need for novel drug development to enhance current treatment protocols. Ziyuglycoside II (ZYG II), a triterpenoid saponin extracted from S. officinalis, has recently demonstrated antitumor properties. This study evaluates the antitumor effect of ZYG II on osteosarcoma and elucidates its mechanism of action through the co-regulation of p53 and estrogen-related receptor gamma (ESRRG), which inhibits disease progression. The research employs in vitro experiments using multiple established osteosarcoma cell lines, as well as in vivo studies utilizing a nude mouse model of orthotopic xenograft osteosarcoma. Additionally, ESRRG shRNA was used to construct stable ESRRG-reducing OS cell lines to investigate the molecular mechanism by which ZYG II exerts its anti-osteosarcoma effects through the co-regulation of ESRRG and p53. Results indicate that ZYG II administration led to decreased OS cell viability and reduced tumor volumes. Furthermore, cell cycles were arrested at the G0/G1 phase, while the proportion of apoptotic cells increased. Expression of p53, ESRRG, p21, Bax, Cleaved Caspase-9, and Cleaved Caspase-3 proteins increased, while expression of CDK4, Cyclin D1, and Bcl-2 proteins decreased. Multiple ZYG II and ESRRG docking patterns were simulated through molecular docking. Comparing the pharmacodynamic response of ZYG II to OS cell lines with reduced ESRRG and normal expression demonstrated that ZYG II inhibits osteosarcoma progression, induces cell cycle arrest, and promotes cell apoptosis through the coordination of p53 and ESRRG. In conclusion, ZYG II inhibits osteosarcoma progression, leads to cell cycle arrest, and promotes cell apoptosis through synergistic regulation of p53 and ESRRG.