Current progress and open challenges for applying tyrosine kinase inhibitors in osteosarcoma

Tyrosine kinase inhibitors in Ewing's sarcoma: a systematic review

Ewing's sarcoma (ES) is a highly aggressive primary bone malignancy that primarily affects children and adolescents. Several tyrosine kinase receptors (RTKs) have been found to be overexpressed in ES samples, and it was demonstrated that some play significant roles in driving the malignant phenotype of ES. Specifically, ES with insulin-like growth factor 1 (IGF1R) or vascular endothelial growth factor (VEGFR) overexpression were correlated with more aggressive ES and worse outcomes. Other RTKs that were determined to be overexpressed in ES include platelet-derived growth factor receptor, stem cell factor receptor, and hepatocyte growth factor. Overexpression of these molecules suggests their possible tumor-driving role, making them potential targets for intervention. Various tyrosine kinase inhibitors (TKIs), including apatinib, anlotinib, and cabozantinib have shown clinical promise in patients with recurrent ES who have progressed on previous lines of therapy. The findings reported in this review emphasize the importance of assessing IGF1R-focused inhibitors and combinational therapeutic regimens in future research. Furthermore, biomarkers predictive of response are necessary to improve patient outcomes. In order to optimize ES care, considerations for patient eligibility on the basis of positivity for biomarkers predictive of response, and the inclusion of quality-of-life evaluations in studies must be addressed.

Advancements in Osteosarcoma Therapy: Overcoming Chemotherapy Resistance and Exploring Novel Pharmacological Strategies

Osteosarcoma is recognized as the most prevalent primary bone malignancy, primarily affecting children and adolescents. It is characterized by its aggressive behavior and high metastatic potential, which often leads to poor patient outcomes. Despite advancements in surgical techniques and chemotherapy regimens, the prognosis for patients with osteosarcoma remains unsatisfactory, with survival rates plateauing over the past few decades. A significant barrier to effective treatment is the development of chemotherapy resistance, which complicates the management of the disease and contributes to high rates of recurrence. This review article aims to provide a comprehensive overview of recent advancements in osteosarcoma therapy, particularly in overcoming chemotherapy resistance. We begin by discussing the current standard treatment modalities, including surgical resection and conventional chemotherapy agents such as methotrexate, doxorubicin, and cisplatin. While these approaches have been foundational in managing osteosarcoma, they are often limited by adverse effects and variability in efficacy among patients. To address these challenges, we explore novel pharmacological strategies that aim to enhance treatment outcomes. This includes targeted therapies focusing on specific molecular alterations in osteosarcoma cells and immunotherapeutic approaches designed to harness the body's immune system against tumors. Additionally, we review innovative drug delivery systems that aim to improve the bioavailability and efficacy of existing treatments while minimizing toxicity. The review also assesses the mechanisms underlying chemotherapy resistance, such as drug efflux mechanisms, altered metabolism, and enhanced DNA repair pathways. By synthesizing current research findings, we aim to highlight the potential of new therapeutic agents and strategies for overcoming these resistance mechanisms. Ultimately, this article seeks to inform future research directions and clinical practices, underscoring the need for continued innovation in treating osteosarcoma to improve patient outcomes and survival rates.

Genetic profiling of osteosarcoma in an adolescent using a next‑generation sequencing panel and Sanger sequencing: A case report and review of the literature

Osteosarcoma (OS) is the most common malignant bone tumor affecting adolescents and young adults and it usually occurs in the long bones of the extremities. The detection of cancer-related genetic alterations has a growing effect in guiding diagnosis, prognosis and targeted therapies. However, little is known about the molecular aspects involved in the etiology and progression of OS, which limits options for targeted therapies. The present study described a case of an adolescent patient (16-years-old) who was diagnosed with conventional central OS in the right distal femur without the evidence of pulmonary metastases; the patient was treated with surgery and adjuvant chemotherapy. Genetic alterations in resected tumor tissue were investigated via next-generation sequencing (NGS) technology using a targeted NGS panel. Sanger sequencing was also performed to investigate somatic and germline TP53 mutations (exons 4-8). NGS analysis revealed an intratumor heterogeneity signature in OS tumor, including several single nucleotide variants identified in genes encoding tyrosine kinase proteins. No PCR products for TP53 exon 5 were detected in the tumor sample by PCR analysis prior to Sanger sequencing, suggesting a significant deletion in this exon. Sanger sequencing analysis revealed the missense variant TP53 c.712T>A (p.Cys238Ser) in tumor tissue sample, thus reinforcing the role of TP53 somatic mutations in OS development. Additionally, the TP53 c.215C>G (p.Pro72Arg) germline missense variant was identified in the peripheral blood sample. In conclusion, the findings provided new information on genetic aspects that may contribute to OS development, especially in pediatric patients.

C1GALT1 expression predicts poor survival in osteosarcoma and is crucial for ABCC1 transporter-mediated doxorubicin resistance

Osteosarcoma is an aggressive bone malignancy with a high propensity for drug resistance and metastasis, leading to poor clinical outcomes. This study investigates the role of core 1 β1,3-galactosyltransferase 1 (C1GALT1) in osteosarcoma, focusing on its implications in chemoresistance. Our findings reveal that high expression of C1GALT1 is associated with advanced stages, adverse overall survival, and increased recurrence rates. Elevated levels of C1GALT1 were observed in doxorubicin-selected osteosarcoma cells, where its suppression significantly promoted doxorubicin-induced apoptosis and reduced drug efflux. Pharmacological inhibition of C1GALT1 using itraconazole replicated these effects, suggesting a potential therapeutic strategy to overcome chemoresistance. Additionally, we identified the involvement of the ATP-binding cassette (ABC) transporter ABCC1 in the drug-resistance phenotype mediated by C1GALT1. C1GALT1-mediated O-glycan changes were found to influence the cell-surface targeting and lysosomal degradation of ABCC1, thereby modulating its efflux capacity. In vitro and in vivo studies confirmed that C1GALT1 impacts ABCC1 expression and function, further supporting its role in osteosarcoma chemoresistance. These results highlight the clinical relevance of C1GALT1 as a biomarker for prognosis and a potential therapeutic target for osteosarcoma. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Whole-Exome Analysis and Osteosarcoma: A Game Still Open

Osteosarcoma (OS) is the most prevalent malignant bone tumor in adolescents and young adults. OS cells grow in a permissive local microenvironment which modulates their behavior and facilitates all steps in tumor development (e.g., proliferation/quiescence, invasion/migration, and drug resistance) and contributes to their intrinsic heterogeneity. The lung parenchyma is the most common metastatic site in OS, and metastatic foci are frequently associated with a poor clinical outcome. Although multiple factors may be responsible for the disease, including genetic mutations (e.g., Rb and p53), the molecular mechanism of development of OS remains unclear, and the conventional treatment for OS is still based on a sequential approach that combines chemotherapy and surgery. Also, despite the increase in clinical trials, the survival rates for OS have not improved. Non-specific targeting therapies thus show poor therapeutic effects, along with side effects at high doses. For these reasons, many efforts have been made to characterize the complex genome of OS thanks to the whole-exome analysis, with the aim of identifying predictive biomarkers to give these patients a better therapeutic option. This review aims to summarize and discuss the main recent advances in OS molecular research for precision medicine.

FBXO22 promotes osteosarcoma progression via regulation of FOXO1 for ubiquitination and degradation

Accumulating evidence has demonstrated that F-box protein 22 (FBXO22) participates in tumour development and progression in various types of human malignancies. However, the functions and detailed molecular mechanisms of FBXO22 in osteosarcoma tumorigenesis and progression remain elusive. In this study, we aimed to determine the effects of FBXO22 on the cell proliferation, migration and invasion of osteosarcoma cells using cell counting kit-8 and Matrigel Transwell approaches. Moreover, we explored the molecular mechanisms by which FBXO22 mediated oncogenesis and progression in osteosarcoma via Western blotting, immunoprecipitation and ubiquitination. We found that FBXO22 depletion inhibited the proliferation, migration and invasion of osteosarcoma cells, whereas FBXO22 overexpression increased the proliferation and motility of osteosarcoma cells. Mechanistically, FBXO22 promoted the ubiquitination and degradation of FoxO1 in osteosarcoma cells. FBXO22 depletion reduced cell proliferation and motility via regulation of FoxO1. Taken together, our findings provide new insight into FBXO22-induced osteosarcoma tumorigenesis. The inhibition of FBXO22 could be a promising strategy for the treatment of osteosarcoma.

Sorafenib Encapsulated Poly(ester amide) Nanoparticles for Efficient and Biosafe Prostate Cancer Therapy

Prostate cancer (PCa) with a high incidence worldwide is a serious threat to men's health. Despite the continuous development of treatment strategies for PCa in recent years, the long-term prognosis of patients is still poor. Hence, the discovery and development of novel, secure, and efficient therapeutic approaches hold significant clinical significance. Although sorafenib (SOR) displays potential as a therapeutic option for PCa, its clinical efficacy is hindered by drug resistance, limited water solubility, and rapid metabolism. Therefore, we proposed to prepare nanoparticles (named SOR@8P4 NPs) utilizing the phenylalanine-based poly(ester amide) polymer (8P4) as the drug carrier to enhance the solubility and drug stability of SOR and improve the therapeutic targeting and bioavailability. SOR@8P4 NPs had high stability and showed acid-responsive drug release at the acidic tumor microenvironment. Additionally, SOR@8P4 NPs demonstrated more remarkable anticancer, antimetastatic, and antiproliferative abilities in vitro, compared with those of free drugs. SOR@8P4 NPs showed high tumor targeting and significantly inhibited tumor growth in vivo. In summary, the drug delivery system of SOR@8P4 NPs provides new ideas for the clinical treatment of PCa.

Antitumor activity of anlotinib in malignant melanoma: modulation of angiogenesis and vasculogenic mimicry

Malignant melanoma presents a formidable challenge due to its aggressive metastatic behavior and limited response to current treatments. To address this, our study delves into the impact of anlotinib on angiogenesis and vasculogenic mimicry using malignant melanoma cells and human umbilical vein endothelial cells. Evaluating tubular structure formation, cell proliferation, migration, invasion, and key signaling molecules in angiogenesis, we demonstrated that anlotinib exerts a dose-dependent inhibition on tubular structures and effectively suppresses cell growth and invasion in both cell types. Furthermore, in a mouse xenograft model, anlotinib treatment resulted in reduced tumor growth and vascular density. Notably, the downregulation of VEGFR-2, FGFR-1, PDGFR-β, and PI3K underscored the multitargeted antitumor activity of anlotinib. Our findings emphasize the therapeutic potential of anlotinib in targeting angiogenesis and vasculogenic mimicry, contributing to the development of novel strategies for combating malignant melanoma.

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.

Imaging Assessment of the Efficacy of Chemotherapy in Primary Malignant Bone Tumors: Recent Advances in Qualitative and Quantitative Magnetic Resonance Imaging and Radiomics

Recent studies have shown that MRI demonstrates promising results for evaluating the chemotherapy efficacy in bone sarcomas. This article reviews current methods for evaluating the efficacy of malignant bone tumors and the application of MRI in this area, and emphasizes the advantages and limitations of each modality. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.

Design, synthesis and anti-osteosarcoma activity study of novel pyrido[2,3-d]pyrimidine derivatives by inhibiting DKK1-Wnt/β-catenin pathway

Osteosarcoma is a common primary malignant bone tumor in adolescents. Wnt/β-catenin has been proved to play a pro-oncogenic role and was overactivated in osteosarcoma. Therefore, this pathway has become an interesting therapeutic target for osteosarcoma. Herein we report the design, synthesis and biological activities of a series of novel pyrido[2,3-d]pyrimidine derivatives based on our previous work. Among these, the representative compound 2-{[1,3-dimethyl-7-(4-methylpiperazin-1-yl)-2,4-dioxo-1,2,3,4-tetrahydropyrido[2,3-d]pyrimidin-5-yl]amino}-N-[4-(trifluoromethoxy)phenyl]acetamide (7m) has exhibited good antiproliferative activity towards 143B and MG63 cells with good selectivity over non-cancerous HSF cells. In the assay of Ca2+ concentration, the compound 7m increased the intracellular Ca2+ concentration in 143B cells. In addition, the expression of DKK1 increased, and that of p-β-catenin decreased by 7m treatment. Finally, the Hoechst 33,342 staining, Annexin-FITC/PI staining and mitochondrial fluorescence staining have clearly demonstrated that compound 7m induced apoptosis in 143B cells.

Tocilizumab (monoclonal anti-IL-6R antibody) reverses anlotinib resistance in osteosarcoma

Purpose

Anlotinib, a tyrosine kinase inhibitor (TKI) has been in clinical application to inhibit malignant cell growth and lung metastasis in osteosarcoma (OS). However, a variety of drug resistance phenomena have been observed in the treatment. We aim to explore the new target to reverse anlotinib resistance in OS.

Materials and Methods

In this study, we established four OS anlotinib-resistant cell lines, and RNA-sequence was performed to evaluate differentially expressed genes. We verified the results of RNA-sequence by PCR, western blot and ELISA assay. We further explored the effects of tocilizumab (anti- IL-6 receptor), either alone or in combined with anlotinib, on the inhibition of anlotinib-resistant OS cells malignant viability by CCK8, EDU, colony formation, apoptosis, transwell, wound healing, Cytoskeletal stain assays, and xenograft nude mouse model. The expression of IL-6 in 104 osteosarcoma samples was tested by IHC.

Results

We found IL-6 and its downstream pathway STAT3 were activated in anlotinib-resistant osteosarcoma. Tocilizumab impaired the tumor progression of anlotinib-resistant OS cells, and combined treatment with anlotinib augmented these effects by inhibiting STAT3 expressions. IL-6 was highly expressed in patients with OS and correlated with poor prognosis.

Conclusion

Tocilizumab could reverse anlotinib resistance in OS by IL-6/STAT3 pathway and the combination treatment with anlotinib rationalized further studies and clinical treatment of OS.