Chondroblastoma metastasis, though rare, represents a clinically significant and notably important aspect of bone tumors. Understanding its epidemiological characteristics, pathological features, and treatment modalities, despite its infrequency, is imperative for comprehensive patient management. This review aims to elucidate the epidemiology, molecular mechanisms, diagnostic challenges, and therapeutic strategies associated with chondroblastoma metastasis. The patterns, prognostic factors, and treatment outcomes were explored through an analysis of case studies and clinical reports. Notably, we highlighted emerging therapeutic perspectives aimed at improving patient outcomes. To the best of our knowledge, there has been no previous review addressing these matters cumulatively, highlighting a significant gap in the existing scholarly literature. By shedding light on the nuances of chondroblastoma metastasis, this review contributes to the advancement of knowledge in this field and informs clinical decision-making for improved patient care.

OBJECTIVE: To investigate the serum lipid profiles of patients with localized osteosarcoma around the knee joint before and after neoadjuvant chemotherapy.
METHODS: After retrospectively screening the data of 742 patients between January 2007 and July 2020, 50 patients aged 13 to 39 years with Enneking stage II disease were included in the study. Serum lipid levels, including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), lipoprotein-α [Lp(a)], and apolipoprotein A1, B, and E (ApoA1, ApoB, and ApoE), and clinicopathological characteristics were collected before and after neoadjuvant chemotherapy.
RESULTS: The mean levels of TC, TG, and ApoB were significantly increased following neoadjuvant chemotherapy (16%, 38%, and 20%, respectively, vs. pretreatment values; P<0.01). The mean levels of LDL-C and ApoE were also 19% and 16% higher, respectively (P<0.05). No correlation was found between the pretreatment lipid profile and the histologic response to chemotherapy. An increase in Lp(a) was strongly correlated with the Ki-67 index (R=0.31, P=0.023). Moreover, a trend toward longer disease-free survival (DFS) was observed in patients with decreased TG and increased LDL-C following chemotherapy, although this difference was not statistically significant (P=0.23 and P=0.24, respectively).
CONCLUSIONS: Significant elevations in serum lipids were observed after neoadjuvant chemotherapy in patients with localized osteosarcoma. There was no prognostic significance of pretreatment serum lipid levels on histologic response to neoadjuvant chemotherapy. The scale of increase in serum Lp(a) might have a potential prognostic role in osteosarcoma. Patients with increased LDL-C or reduced TG after chemotherapy seem to exhibit a trend toward favorable DFS.

OBJECTIVE: Methotrexate (MTX) resistance in osteosarcoma leads to a very poor prognosis. In the present study, in order to further understand the basis and ramifications of MTX resistance in osteosarcoma, we selected an osteosarcoma cell line that has a 5,500-fold-increased MTX IC50 Materials and Methods: The super MTX-resistant 143B osteosarcoma cells (143B-MTXSR) were selected from MTX-sensitive parental human 143B osteosarcoma cells (143B-P) by continuous culture with step-wise increased amounts of MTX. To compare the malignancy of 143B-MTXSR and 143B-P, colony-formation capacity was compared with clonogenic assays on plastic and in soft agar. In addition, tumor growth was compared with orthotopic xenograft mouse models of osteosarcoma. Expression of dihydrofolate reductase (DHFR), phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR), and myelocytomatosis oncogene (MYC) was examined with western immunoblotting and compared in 143B-MTXSR and 143B-P cells.
RESULTS: 143B-MTXSR had a 5,500-fold increase in the MTX IC50 compared to the parental 143B-P cells. Expression of DHFR was increased 10-fold in 143B-MTXSR compared to 143B-P (p<0.01). 143B-MTXSR cells had reduced colony-formation capacity on plastic (p=0.032) and in soft agar (p<0.01) compared to 143B-P and reduced tumor growth in orthotopic xenograft mouse models (p<0.001). These results demonstrate that 143B-MTXSR had reduced malignancy. 143B-MTXSR also showed an increased expression of PI3K (p<0.01), phosphorylated (activated) AKT (p=0.031), phosphorylated mTOR (p=0.043), and c-MYC (p=0.024) compared to 143B-P.
CONCLUSIONS: The present study demonstrates that the increased expression of DHFR, PI3K/AKT/mTOR and c-MYC appears to be linked to super MTX resistance and, paradoxically, to reduced malignancy. The present results suggest that DHFR may be a powerful tumor suppressor when highly amplified.

A \"Think Tank for Osteosarcoma\" medical advisory board meeting was held in Santa Monica, CA, USA on February 2-3, 2024. The goal was to develop a strategic approach to prevent recurrence of osteosarcoma. Osteosarcoma metabolism and the genomic instability of osteosarcoma, immunotherapy for osteosarcoma, CAR-T cell therapy, DeltaRex-G tumor-targeted gene therapy, repurposed drugs, alternative medicines, and personalized medicine were discussed. Only DeltaRex-G was voted on. The conclusions were the following: No intervention has been demonstrated to improve survival in a clinical trial. Additionally, the consensus (10/12 in favor) was that DeltaRex-G without immunotherapy may be administered for up to one year. Phase 2/3 randomized studies of DeltaRex-G should be performed to determine whether the incidence of recurrence could be reduced in high-risk individuals. Furthermore, a personalized approach using drugs with minimal toxicity could be attempted with the acknowledgement that there are no efficacy data to base this on. Repurposed drugs and alternative therapies should be tested in mouse models of osteosarcoma. Moreover, unmodified IL-2 primed Gamma Delta (NK) cell therapy may be used to prevent recurrence. Lastly, rapid development of CAR-T cell therapy is recommended, and an institute dedicated to the study of osteosarcoma is needed.

BACKGROUND: Osteosarcoma (OS), the most prevalent primary bone malignancy, exhibits rapid growth and a high tendency for lung metastasis, posing significant treatment challenges. Ziyuglycoside II (ZGS II), a main active compound derived from Sanguisorba officinalis l., has shown potential in cancer treatment. However, the effects of ZGS II and its potential mechanism in OS remain elusive.
OBJECTIVE: This study aims to explore the anti-metastatic potential of ZGS II in OS, offering a novel therapeutic strategy for improved patient outcomes.
METHODS: Cell viability and proliferation was detected by cell counting kit-8 (CCK-8) and clone formation assay, respectively. Transwell and wound-healing assay were applied to evaluate the potential metastatic abilities of OS cells in vitro. More critically, the chromobox protein homolog 4 (CBX4) and Wnt/β-catenin signaling pathway was investigated utilizing Western blotting, immunohistochemistry, shRNA knockdown and immunofluorescence. An orthotopic metastasis mouse model was utilized to evaluate the efficacy of ZGS II in suppressing OS metastasis in vivo, with molecular docking studies conducted to elucidate the interaction between ZGS II and the CBX4 protein.
RESULTS: Our study demonstrated the potent inhibitory effects of ZGS II on OS cell proliferation and induced apoptosis in vitro, as evidenced by decreased cell viability, enhanced caspase-3 activation, and mitochondrial dysfunction. Furthermore, using an orthotopic metastasis mouse model, we illustrated that ZGS II effectively suppressed tumor growth and lung metastasis in vivo. Notably, our investigation revealed that the antitumor action of ZGS II is dependent on the reduction of CBX4 levels, leading to the attenuation of the Wnt/β-catenin signaling pathway activation. Molecular docking analyses supported this pathway\'s suppression, showing that ZGS II has the capability to directly bind and disrupt CBX4 function. To further confirm this mechanism, we utilized shRNA to silence CBX4 in OS cells, which significantly enhanced the inhibitory impact of ZGS II on cell migration.
CONCLUSIONS: Our study findings reveal that ZGS II efficiently suppresses both metastasis and tumor growth in OS by a novel mechanism that entails the inhibition of the CBX4-regulated Wnt/β-catenin pathway. These outcomes highlight the promising potential of ZGS II as a therapeutic agent for managing metastatic OS, thus justifying the need for additional clinical investigations.

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

Osteosarcoma (OS) in humans is characterized by alterations in the TP53 gene. In mice, loss of p53 triggers OS development, for which c-Myc (Myc) oncogenicity is indispensable. However, little is known about which genes are targeted by Myc to promote tumorigenesis. Here, we examined the role of γ-glutamylcyclotransferase (Ggct) which is a component enzyme of the γ-glutamyl cycle essential for glutathione homeostasis, in human and mouse OS development. We found that GGCT is a poor prognostic factor for human OS, and that deletion of Ggct suppresses p53-deficient osteosarcomagenesis in mice. Myc upregulates Ggct directly by binding to the Ggct promoter, and deletion of a Myc binding site therein by genome editing attenuated the tumorigenic potential of p53-deficient OS cells. Taken together, these results show a rationale that GGCT is widely upregulated in cancer cells and solidify its suitability as a target for anticancer drugs.

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

The renin-angiotensin system (RAS) is increasingly being recognized to play a role in the tumor microenvironment, promoting tumor growth. Studies blocking a single part of the RAS have shown mixed results, possibly due to the existence of different bypass pathways and redundancy within the RAS. As such, multimodal blockade of the RAS has been developed to exert more complete inhibition of the RAS. The aim of the present study was to assess the safety of multimodal RAS blockade in dogs. Five dogs (four with appendicular osteosarcoma, one with oral malignant melanoma) were treated with atenolol, benazepril, curcumin, meloxicam, and metformin. The dogs underwent clinical examination, blood pressure measurement, and hematology and serum biochemistry tests performed at 0, 1, 3, 6, 9, and 12 weeks, then every 3 months thereafter. End-of-life decisions were made by the owners. None of the dogs developed hypotension. One dog had intermittent vomiting during the 64 weeks it was on the trial. One dog had a one-off increase in serum SDMA(symmetrical dimethylarginine) concentration. Dogs were euthanized at weeks 3 (osteosarcoma), 10 (osteosarcoma), 17 (osteosarcoma), and 26 (oral malignant melanoma), and one dog was still alive at the end of the trial at 64 weeks (osteosarcoma). This is the first assessment of multimodal blockade of the RAS in dogs, and the results suggest it causes only mild adverse effects in some animals. The efficacy of the treatment was not assessed due to the small number of dogs. This pilot study allows for future larger studies assessing multimodal RAS blockade for the treatment of canine cancer.

A multimodal mass spectrometry imaging (MSI) approach was used to investigate the chemotherapy drug-induced response of a Multicellular Tumour Spheroid (MCTS) 3D cell culture model of osteosarcoma (OS). The work addresses the critical demand for enhanced translatable early drug discovery approaches by demonstrating a robust spatially resolved molecular distribution analysis in tumour models following chemotherapeutic intervention. Advanced high-resolution techniques were employed, including desorption electrospray ionisation (DESI) mass spectrometry imaging (MSI), to assess the interplay between metabolic and cellular pathways in response to chemotherapeutic intervention. Endogenous metabolite distributions of the human OS tumour models were complemented with subcellularly resolved protein localisation by the detection of metal-tagged antibodies using Imaging Mass Cytometry (IMC). The first application of matrix-assisted laser desorption ionization-immunohistochemistry (MALDI-IHC) of 3D cell culture models is reported here. Protein localisation and expression following an acute dosage of the chemotherapy drug doxorubicin demonstrated novel indications for mechanisms of region-specific tumour survival and cell-cycle-specific drug-induced responses. Previously unknown doxorubicin-induced metabolite upregulation was revealed by DESI-MSI of MCTSs, which may be used to inform mechanisms of chemotherapeutic resistance. The demonstration of specific tumour survival mechanisms that are characteristic of those reported for in vivo tumours has underscored the increasing value of this approach as a tool to investigate drug resistance.