IRF5 suppresses metastasis through the regulation of tumor-derived extracellular vesicles and pre-metastatic niche formation.

Metastasis is driven by extensive cooperation between a tumor and its microenvironment, resulting in the adaptation of molecular mechanisms that evade the immune system and enable pre-metastatic niche (PMN) formation. Little is known of the tumor-intrinsic factors that regulate these mechanisms. Here we show that expression of the transcription factor interferon regulatory factor 5 (IRF5) in osteosarcoma (OS) and breast carcinoma (BC) clinically correlates with prolonged survival and decreased secretion of tumor-derived extracellular vesicles (t-dEVs). Conversely, loss of intra-tumoral IRF5 establishes a PMN that supports metastasis. Mechanistically, IRF5-positive tumor cells retain IRF5 transcripts within t-dEVs that contribute to altered composition, secretion, and trafficking of t-dEVs to sites of metastasis. Upon whole-body pre-conditioning with t-dEVs from IRF5-high or -low OS and BC cells, we found increased lung metastatic colonization that replicated findings from orthotopically implanted cancer cells. Collectively, our findings uncover a new role for IRF5 in cancer metastasis through its regulation of t-dEV programming of the PMN.

Telangiectatic osteosarcoma of the mandible-A rare case report and an insight into differential diagnosis.

Telangiectatic osteosarcoma (TOS) is a rare variant of osteosarcoma that typically affects young individuals and long bones. The case under discussion was seen in the mandible of a 57-year-old female and had rapidly grown in size within a week. Microscopically, the tumour was characterised by large vascular cavities surrounded by anaplastic cells. Thin lacy tumour osteoid was observed at various foci. Abundant multinucleated osteoclastic giant cells along with areas of necrosis were also noted. The tumour cells were positive for SATB2, while negative for Cytokeratin AE1/3, CD 34. Ki-67 positivity was observed in more than 50% of tumour cells. A diagnosis of high grade telangiectatic osteosarcoma was thus made.

MgSiO3 Fiber Membrane Scaffold with Triggered Drug Delivery for Osteosarcoma Synergetic Therapy and Bone Regeneration.

In this research, a novel MgSiO3 fiber membrane (MSFM) loaded with indocyanine green (ICG) and doxorubicin (DOX) was prepared. Because of MgSiO3's unique lamellar structure composed of a silicon-oxygen tetrahedron, magnesium ion (Mg2+) moves easily and can be further replaced with other cations. Therefore, because of the positively charged functional group of ICG, MSFM has a rather high drug loading for ICG. In addition, there is electrostatic attraction between DOX (a cationic drug) and ICG (an anionic drug). Hence, after loading ICG, more DOX can be adsorbed into MSFM because of electrostatic interaction. The ICG endows the MSFM outstanding photothermal therapy (PTT) performance, and DOX as a chemotherapeutic drug can restrain tumor growth. On the one hand, H+ exchanged with the positively charged DOX based on the MgSiO3 special lamellar structure. On the other hand, the thermal effect could break the electrostatic interaction between ICG and DOX. Based on the above two points, both tumor acidic microenvironment and photothermal effect can trigger DOX release. What's more, in vitro and in vivo antiosteosarcoma therapy evaluations displayed a superior synergetic PTT-chemotherapy anticancer treatment and excellent biocompatibility of DOX&ICG-MSFM. Finally, the MSFM was proven to greatly promote cell proliferation, differentiation, and bone regeneration performance in vitro and in vivo. Therefore, MSFM provides a creative perspective in the design of multifunctional scaffolds and shows promising applications in controlled drug delivery, antitumor performance, and osteogenesis.

Is still effective massive allograft reconstruction in parosteal osteosarcoma of the distal femur? Review of the literature and advantages of newer technologies.

PURPOSE: Parosteal Osteosarcoma is a well-differentiated, low-grade bone sarcoma. It most commonly occurs in the third decade of life, usually in the distal femur. This study aims to perform a literature review about the types of reconstructions reported and to analyze the results of an updated technique of resection using custom-made 3D-printed cutting guides. METHODS: We perform a systematic literature review about parosteal osteosarcoma, evaluating treatments, margins, local recurrence, complications, and functional results when available. We also report a case treated in our Center with a revisited technique introducing custom-made 3D-printed cutting guides. RESULTS: We analyzed 12 studies with a total of 151 patients. The distal femur was the most frequently reported site (81.5%). After distal femur resection, reconstruction was performed with graft in most cases (48%), followed by prosthetic reconstruction (40%). Margins were wide in 85.5% of cases. The total incidence of local recurrence was 11%. Functional results were excellent in all cases, with a mean MSTS score of 86%. In our case, with the help of the jigs, the surgical technique was relatively easy, graft fusion excellent and fast, margins wide, and functional results excellent. CONCLUSIONS: In the literature, the most commonly used type of reconstruction after resection is biological with graft. Indeed, despite the increasing number of prosthetic reconstructions, the historical diaphysometaphyseal hemiresection and graft is still indicated in parosteal osteosarcoma of the distal femur. New technologies, such as the jigs we used, allow significant advantages during the procedure: reduce the resection and graft preparation time, allow a better match between components, and help to obtain safer margins, sparing as much bone as possible.

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

Background: The current understanding of the mechanisms by which metal ion metabolism promotes the progression and drug resistance of osteosarcoma remains incomplete. This study aims to elucidate the key roles and mechanisms of genes involved in cuproptosis-related sphingolipid metabolism (cuproptosis-SPGs) in regulating the immune landscape, tumor metastasis, and drug resistance in osteosarcoma cells. Methods: This study employed multi-omics approaches to assess the impact of cuproptosis-SPGs on the prognosis of osteosarcoma patients. Lasso regression analysis was utilized to construct a prognostic model, while multivariate regression analysis was applied to identify key core genes and generate risk coefficients for these genes, thereby calculating a risk score for each osteosarcoma patient. Patients were then stratified into high-risk and low-risk groups based on their risk scores. The ESTIMATE and CIBERSORT algorithms were used to analyze the level of immune cell infiltration within these risk groups to construct the immune landscape. Single-cell analysis was conducted to provide a more precise depiction of the expression patterns of cuproptosis-SPGs among immune cell subtypes. Finally, experiments on osteosarcoma cells were performed to validate the role of the cuproptosis-sphingolipid signaling network in regulating cell migration and apoptosis. Results: In this study, seven cuproptosis-SPGs were identified and used to construct a prognostic model for osteosarcoma patients. In addition to predicting survival, the model also demonstrated reliability in forecasting the response to chemotherapy drugs. The results showed that a high cuproptosis-sphingolipid metabolism score was closely associated with reduced CD8 T cell infiltration and indicated poor prognosis in osteosarcoma patients. Cellular functional assays revealed that cuproptosis-SPGs regulated the LC3B/ERK signaling pathway, thereby triggering cell death and impairing migration capabilities in osteosarcoma cells. Conclusion: The impact of cuproptosis-related sphingolipid metabolism on the survival and migration of osteosarcoma cells, as well as on CD8 T cell infiltration, highlights the potential of targeting copper ion metabolism as a promising strategy for osteosarcoma patients.

Extraskeletal osteosarcoma infiltrating pancreas, spleen, gastric, and left kidney: a case report.

BACKGROUND: Extraskeletal osteosarcoma is an extremely rare malignancy that accounts for 1% of soft tissue sarcoma and 4.3% of all osteosarcoma. Extraskeletal osteosarcoma can develop in a patient between the ages of 48 and 60 years. The incidence of extraskeletal osteosarcoma is slightly higher in male patients than in females. CASE PRESENTATION: A 50-year-old Caucasian male patient presented with a 6-month history of intermittent lower-left back pain that limits his activity. Prior ultrasonography and abdominal computed tomography scan showed a diagnosis of kidney stone and tumor in the lower-left abdomen. The computed tomography urography with contrast revealed a mass suspected as a left retroperitoneal malignant tumor. Hence, the tumor was resected through laparotomy and the patient continued with histopathological and immunohistochemistry examination with the result of extraskeletal osteosarcoma. CONCLUSION: Extraskeletal osteosarcoma presents diagnostic challenges requiring multimodal examination, including histological and immunohistochemistry analyses. This case underscores the aggressive nature and poor prognosis despite undergoing the current suggested treatment.

Identification of a pro-protein synthesis osteosarcoma subtype for predicting prognosis and treatment.

Osteosarcoma (OS) is a heterogeneous malignant spindle cell tumor that is aggressive and has a poor prognosis. Although combining surgery and chemotherapy has significantly improved patient outcomes, the prognosis for OS patients with metastatic or recurrent OS has remained unsatisfactory. Therefore, it is imperative to gain a fresh perspective on OS development mechanisms and treatment strategies. After studying single-cell RNA sequencing (scRNA-seq) data in public databases, we identified seven OS subclonal types based on intra-tumor heterogeneity. Subsequently, we constructed a prognostic model based on pro-protein synthesis osteosarcoma (PPS-OS)-associated genes. Correlation analysis showed that the prognostic model performs extremely well in predicting OS patient prognosis. We also demonstrated that the independent risk factors for the prognosis of OS patients were tumor primary site, metastatic status, and risk score. Based on these factors, nomograms were constructed for predicting the 3- and 5-year survival rates. Afterward, the investigation of the tumor immune microenvironment (TIME) revealed the vital roles of γδ T-cell and B-cell activation. Drug sensitivity analysis and immune checkpoint analysis identified drugs that have potential application value in OS. Finally, the jumping translocation breakpoint (JTB) gene was selected for experimental validation. JTB silencing suppressed the proliferation, migration, and invasion of OS cells. Therefore, our research suggests that PPS-OS-related genes facilitate the malignant progression of OS and may be employed as prognostic indicators and therapeutic targets in OS.

Single-cell transcriptomic insights into chemotherapy-induced remodeling of the osteosarcoma tumor microenvironment.

PURPOSE: Neoadjuvant chemotherapy serves as an effective strategy for treating osteosarcoma (OS) not only by targeting cancerous cells but also by influencing the tumor's immune and stromal elements. Gaining insights into how chemotherapy reshapes the tumor's local environment is crucial for advancing OS treatment protocols. METHODS: Using single-cell RNA sequencing, this study analyzed tumor samples from patients with advanced osteosarcoma collected both before and after chemotherapy. RESULTS: The results revealed that chemotherapy caused the remaining OS cells to express higher levels of genes associated with stemness. Additionally, this process enhances the presence of cancer-associated fibroblasts, increasing their ability to modify the extracellular matrix (ECM). Chemotherapy also increases the number of endothelial cells, albeit with compromised differentiation capabilities. Importantly, the treatment reduced the immune cell population, including myeloid and T/NK cells, particularly impacting the subpopulations with tumor-fighting capabilities. CONCLUSION: These findings highlight the complex reaction of the tumor environment to chemotherapy, providing valuable insights into how chemotherapy influences OS cells and the tumor microenvironment (TME). This knowledge is essential for understanding OS resistance mechanisms to treatments, potentially guiding the development of novel therapies for managing advanced OS.

Endoprosthetic replacement with preservation of the epiphysis for proximal tibial reconstruction after osteosarcoma resection in children: a case report.

BACKGROUND: Limb salvage surgery is an important method for treating malignant tumors of the bone involving the adjacent parts of the major joints in children. This technique allows for preservation of limb function, especially in the lower limb. However, the reconstruction of the proximal end of the tibia after removing the tumor mass with a rational scale to preserve the total knee joint and reduce limb length discrepancy presents a challenge. CASE PRESENTATION: We present a case of osteosarcoma of the proximal tibia. After being treated with an extended tumor resection, the proximal tibia of the child was restructured using endoprosthetic replacement with epiphyseal preservation. This procedure preserves the entire articular surface and growth plate of the knee joint of the affected limb and provides a feasible alternative protocol for retaining the function and growth potential of the affected limb. The patient remained disease-free and normal limb motor function was observed during the 3.5 year follow-up since the initial surgery. CONCLUSIONS: Preservation of the epiphysis enabled our patient to perform better limb function after limb-saving surgery as a result of his undamaged knee joint and minimized limb-length discrepancy. We believe that endoprosthetic replacement with preservation of the epiphysis can provide the best strategy for reconstruction after resection of focal malignant tumors in long bones without epiphytic involvement.

Examining the emotional healing process through bibliotherapy in adolescents with cancer: A qualitative descriptive study.

PURPOSE: This study aimed to investigate how interactive bibliotherapy impacted the emotional healing process of adolescents with cancer, drawing upon the three-stage emotional healing process theory-identification, catharsis, and insight. METHOD: A qualitative descriptive study was conducted on data from 14 adolescents, aged 10-19 years, diagnosed with or relapsing from leukemia or osteosarcoma within the past two years. Participants received two interactive bibliotherapy sessions using The Rabbit Listened and You Are Special. Data were collected through semistructured interviews and content analyzed. RESULTS: Analysis identified six themes in The Rabbit Listened and eight in You Are Special. Adolescents primarily engaged in identification, empathizing with protagonists and recalling personal experiences. They underwent catharsis, releasing negative emotions and fostering positivity. Insights emerged on companionship, listening, and others' criticism. CONCLUSIONS: Our study validates the use of the three-stage emotional healing process in interdisciplinary bibliotherapy for understanding emotional changes in adolescents with cancer. It sheds light on their concerns and coping strategies. Healthcare practitioners can utilize interactive bibliotherapy based on this framework to initiate therapeutic communication with adolescent cancer patients and improve interventions and care.

Curcumin inhibits the proliferation and migration of osteosarcoma by regulating the expression of super-enhancer-associated genes. / å§œé»„ç´ é€šè¿‡è°ƒæŽ§è¶ çº§å¢žå¼ºå­ç›¸å ³åŸºå› æŠ‘åˆ¶éª¨è‚‰ç˜¤çš„å¢žæ®–å’Œè¿ç§».

OBJECTIVES: Super-enhancer-associated genes may be closely related to the progression of osteosarcoma, curcumin exhibits a certain inhibitory effect on tumors such as osteosarcoma. This study aims to investigate the effects of curcumin on osteosarcoma in vitro and in vivo, and to determine whether curcumin can inhibit the progression of osteosarcoma by suppressing the expression of super-enhancer-associated genes LIM and senescent cell antigen-like-containing domain 1 (LIMS1), secreted protein acidic and rich in cysteine (SPARC), and sterile alpha motif domain containing 4A (SAMD4A). METHODS: Human osteosarcoma cell lines (MG63 cells or U2OS cells) were treated with 5 to 50 µmol/L curcumin for 24, 48, and 72 hours, followed by the methyl thiazolyl tetrazolium (MTT) assay to detect cell viability. Cells were incubated with dimethyl sulfoxide (DMSO) or curcumin (2.5, 5.0 µmol/L) for 7 days, and a colony formation assay was used to measure in vitro cell proliferation. After treatment with DMSO or curcumin (10, 15 µmol/L), a scratch healing assay and a transwell migration assay were performed to evaluate cell migration ability. Real-time reverse transcription polymerase chain reaction (real-time RT-PCR) and Western blotting were used to detect mRNA and protein expression levels of LIMS1, SPARC, and SAMD4A in the cells. An osteosarcoma-bearing nude mouse model was established, and curcumin was administered via gavage for 14 days to assess the impact of curcumin on tumor volume and weight in vivo. Real-time RT-PCR was used to measure mRNA expression levels of LIMS1, SPARC, and SAMD4A in the cancer and adjacent tissues from 12 osteosarcoma patients. RESULTS: After treating cells with different concentrations of curcumin for 24, 48, and 72 hours, cell viability were all significantly decreased. Compared with the DMSO group, the colony formation rates in the 2.5 µmol/L and 5.0 µmol/L curcumin groups significantly declined (both P<0.01). The scratch healing assay showed that, compared with the DMSO group, the migration rates of cells in the 10 µmol/L and 15 µmol/L curcumin groups were significantly reduced. The exception was the 10 µmol/L curcumin group at 24 h, where the migration rate of U2OS cells did not show a statistically significant difference (P>0.05), while all other differences were statistically significant (P<0.01 or P<0.001). The transwell migration assay results showed that the number of migrating cells in the 10 µmol/L and 15 µmol/L curcumin groups was significantly lower than that in the DMSO group (both P<0.001). In the in vivo tumor-bearing mouse experiment, the curcumin group showed a reduction in tumor mass (P<0.01) and a significant reduction in tumor volume (P<0.001) compared with the control group. Compared with the DMSO group, the mRNA expression levels of LIMS1, SPARC, and SAMD4A in the 10 µmol/L and 15 µmol/L curcumin groups were significantly down-regulated (all P<0.05). Additionally, the protein expression level of LIMS1 in U2OS cells in the 10 µmol/L curcumin group was significantly lower than that in the DMSO group (P<0.05). Compared with adjacent tissues, the mRNA expression level of SPARC in osteosarcoma tissues was significantly increased (P<0.001), while the mRNA expression levels of LIMS1 and SAMD4A did not show statistically significant differences (both P>0.05). CONCLUSIONS: Curcumin inhibits the proliferation and migration of osteosarcoma both in vitro and in vivo, which may be associated with the inactivation of super-enhancer-associated gene LIMS1.

Clinical application of LARS tumor tube in joint function reconstruction of tumor type artificial hip replacement. / LARSè‚¿ç˜¤ç®¡åœ¨è‚¿ç˜¤åž‹äººå·¥é«‹å ³èŠ‚ç½®æ¢æœ¯å ³èŠ‚åŠŸèƒ½é‡å»ºä¸­çš„ä¸´åºŠåº”ç”¨.

OBJECTIVES: Proximal femur tumor resection often leads to hip joint instability and functional loss. Various methods have been clinically applied to repair hip joint soft tissue function, but deficiencies remain. This study aims to evaluate the advantages and disadvantages of the ligament advanced reinforcement system (LARS) tumor tube in assisting soft tissue function reconstruction in patients undergoing tumor type artificial hip replacement surgery. METHODS: This study included 85 patients (41 males, 44 females) with proximal femoral tumors treated at the Xiangya Bone Tumor Treatment Center from January 2012 to January 2022, aged 10 to 79 (38.5±18.2) years. Among them, 13 cases had benign aggressive tumors, 45 had primary malignant bone tumors, and 27 had bone metastases. Clinical data, imaging data, and intraoperative photos were collected. Patients were followed up and postoperative functional evaluations were conducted using the Musculoskeletal Tumor Society (MSTS) scoring system and Harris hip joint scoring system to assess limb function and hip joint function. RESULTS: Preoperative pathological fractures were present in 37 cases (43.5%), with a lesion length of (9.4±2.9) cm. Among non-metastatic tumor patients, 7 experienced postoperative recurrence, including 6 cases of osteosarcoma and 1 case of fibrosarcoma. Pulmonary metastases occurred in 9 osteosarcoma patients. Five patients required reoperation due to postoperative complications, including 3 cases of deep vein thrombosis, 1 case of giant cell granuloma, and 1 case of prosthesis infection. Postoperatively, 5 patients exhibited Trendelenburg gait, and 6 had leg length discrepancies. The postoperative MSTS score was 26.7±1.4, and the Harris score was 89.6±5.3. CONCLUSIONS: The LARS tumor tube can effectively assist in reconstructing the soft tissue function of the hip joint and greatly reduce postoperative complications, making it an effective technical improvement in joint function reconstruction in tumor type artificial hip replacement surgery.

LncRNA HOXA-AS3 promotes cell proliferation and invasion via targeting miR-218-5p/FOXP1 axis in osteosarcoma.

Osteosarcoma is an aggressive form of bone cancer and affects the health in children and adolescents. Although conventional treatment improves the osteosarcoma survival, some patients have metastasis and drug resistance, leading to a worse prognosis. Therefore, it is necessary to explore the molecular mechanism of osteosarcoma occurrence and progression, which could discover the novel treatment for osteosarcoma. Long noncoding RNAs (lncRNAs) have been reported to regulate osteosarcoma occurrence and malignant progression. LncRNA HOXA-AS3 facilitates the tumorigenesis and progression in a variety of human cancers. However, the underlying mechanism of lncRNA HOXA-AS3-induced oncogenesis is poorly determined in osteosarcoma. To address this point, we utilized several cellular biological strategies and molecular approaches to explore the biological functions and mechanisms of lncRNA HOXA-AS3 in osteosarcoma cells. We found that lncRNA HOXA-AS3 facilitates cell proliferation and invasion via targeting miR-218-5p/FOXP1 axis in osteosarcoma. In conclusion, lncRNA HOXA-AS3 could be a promising target for osteosarcoma treatment.

LncRNAs as potential prognosis/diagnosis markers and factors driving drug resistance of osteosarcoma, a review.

Osteosarcoma is a common malignancy that often occurs in children, teenagers and young adults. Although the treatment strategy has improved, the results are still poor for most patients with metastatic or recurrent osteosarcomas. Therefore, it is necessary to identify new and effective prognostic biomarkers and therapeutic targets for diseases. Human genomes contain lncRNAs, transcripts with limited or insufficient capacity to encode proteins. They have been implicated in tumorigenesis, particularly regarding the onset, advancement, resistance to treatment, recurrence and remote dissemination of malignancies. Aberrant lncRNA expression in osteosarcomas has been reported by numerous researchers; lncRNAs have the potential to exhibit either oncogenic or tumor-suppressing behaviors and thus, to govern the advancement of this skeletal cancer. They are suspected to influence osteosarcoma cell growth, replication, invasion, migration, remote dissemination and programmed cell death. Additionally, they have been recognized as clinical markers, and may participate in the development of multidrug resistance. Therefore, the study of lncRNAs in the growth, metastasis, treatment and prognosis of osteosarcoma is very important for the active prevention and treatment of osteosarcoma. Consequently, this work reviews the functions of lncRNAs.

A novel prognostic signature related to programmed cell death in osteosarcoma.

Background: Osteosarcoma primarily affects children and adolescents, with current clinical treatments often resulting in poor prognosis. There has been growing evidence linking programmed cell death (PCD) to the occurrence and progression of tumors. This study aims to enhance the accuracy of OS prognosis assessment by identifying PCD-related prognostic risk genes, constructing a PCD-based OS prognostic risk model, and characterizing the function of genes within this model. Method: We retrieved osteosarcoma patient samples from TARGET and GEO databases, and manually curated literature to summarize 15 forms of programmed cell death. We collated 1621 PCD genes from literature sources as well as databases such as KEGG and GSEA. To construct our model, we integrated ten machine learning methods including Enet, Ridge, RSF, CoxBoost, plsRcox, survivalSVM, Lasso, SuperPC, StepCox, and GBM. The optimal model was chosen based on the average C-index, and named Osteosarcoma Programmed Cell Death Score (OS-PCDS). To validate the predictive performance of our model across different datasets, we employed three independent GEO validation sets. Moreover, we assessed mRNA and protein expression levels of the genes included in our model, and investigated their impact on proliferation, migration, and apoptosis of osteosarcoma cells by gene knockdown experiments. Result: In our extensive analysis, we identified 30 prognostic risk genes associated with programmed cell death (PCD) in osteosarcoma (OS). To assess the predictive power of these genes, we computed the C-index for various combinations. The model that employed the random survival forest (RSF) algorithm demonstrated superior predictive performance, significantly outperforming traditional approaches. This optimal model included five key genes: MTM1, MLH1, CLTCL1, EDIL3, and SQLE. To validate the relevance of these genes, we analyzed their mRNA and protein expression levels, revealing significant disparities between osteosarcoma cells and normal tissue cells. Specifically, the expression levels of these genes were markedly altered in OS cells, suggesting their critical role in tumor progression. Further functional validation was performed through gene knockdown experiments in U2OS cells. Knockdown of three of these genes-CLTCL1, EDIL3, and SQLE-resulted in substantial changes in proliferation rate, migration capacity, and apoptosis rate of osteosarcoma cells. These findings underscore the pivotal roles of these genes in the pathophysiology of osteosarcoma and highlight their potential as therapeutic targets. Conclusion: The five genes constituting the OS-PCDS model-CLTCL1, MTM1, MLH1, EDIL3, and SQLE-were found to significantly impact the proliferation, migration, and apoptosis of osteosarcoma cells, highlighting their potential as key prognostic markers and therapeutic targets. OS-PCDS enables accurate evaluation of the prognosis in patients with osteosarcoma.

The Variable Genomic Landscape During Osteosarcoma Progression: Insights From a Longitudinal WGS Analysis.

Osteosarcoma is a primary bone tumor that exhibits a complex genomic landscape characterized by gross chromosomal abnormalities. Osteosarcoma patients often develop metastatic disease, resulting in limited therapeutic options and poor survival rates. To gain knowledge on the mechanisms underlying osteosarcoma heterogeneity and metastatic process, it is important to obtain a detailed profile of the genomic alterations that accompany osteosarcoma progression. We performed WGS on multiple tissue samples from six patients with osteosarcoma, including the treatment naïve biopsy of the primary tumor, resection of the primary tumor after neoadjuvant chemotherapy, local recurrence, and distant metastases. A comprehensive analysis of single-nucleotide variants (SNVs), structural variants, copy number alterations (CNAs), and chromothripsis events revealed the genomic heterogeneity during osteosarcoma progression. SNVs and structural variants were found to accumulate over time, contributing to an increased complexity of the genome of osteosarcoma during disease progression. Phylogenetic trees based on SNVs and structural variants reveal distinct evolutionary patterns between patients, including linear, neutral, and branched patterns. The majority of osteosarcomas showed variable copy number profiles or gained whole-genome doubling in later occurrences. Large proportions of the genome were affected by loss of heterozygosity (LOH), although these regions remain stable during progression. Additionally, chromothripsis is not confined to a single early event, as multiple other chromothripsis events may appear in later occurrences. Together, we provide a detailed analysis of the complex genome of osteosarcomas and show that five of six osteosarcoma genomes are highly dynamic and variable during progression.

Efficacy and safety of sorafenib in adult metastatic osteosarcoma patients.

BACKGROUND: There are limited data on the efficacy of targeted therapy in metastatic osteosarcoma. The goal of this study was to assess the effectiveness of sorafenib in adult patients with heavily pretreated metastatic osteosarcoma. METHOD: Patients with metastatic osteosarcoma aged more than 18 years were assessed retrospectively. The patients' clinical, pathological, and therapeutic data were collected. For survival analysis, Kaplan-Meier models were used. RESULTS: The research involved 15 patients. The ratio of male and female patients was 2/1, with a median age of 25 years (range: 19-64 years). The most common primary tumor localization was the extremities (66.6%). Fourteen (93.3%) patients had previously received palliative chemotherapy and six (40%) patients had palliative radiotherapy. The median progression-free survival was found as 5.5 months (95% confidence interval, 1.3-9.7). A stable response was observed in seven (46.6%) patients and progressive disease in eight (53.4%) patients. Grade 1-2 toxicities were detected in 50% of the patients, while grade 3-4 toxicities were observed in 14.3% of the patients. CONCLUSIONS: We demonstrated real-life results of sorafenib for disease management in pretreated adult patients with metastatic osteosarcoma in the study. Sorafenib was effective for disease control and well tolerated in the patients. Sorafenib may be a treatment option for disease control after the disease progresses with chemotherapy in patients with metastatic osteosarcoma.

Nanopore DNA Sequencing Detected Chromothripsis-Induced PAFAH1B1::USP6 Rearrangement in Periosteal Solid Aneurysmal Bone Cyst Initially Diagnosed as Osteosarcoma.

An aneurysmal bone cyst (ABC) is a benign bone neoplasm that typically occurs during the first and second decades of life. ABC usually presents as a rapidly growing intramedullary expansile mass with multiple blood-filled cysts in the metaphysis of the long tubular bones. Here, we report a case of a periosteal solid ABC that was initially diagnosed as a high-grade surface osteosarcoma. A 10-year-old male was referred to our hospital for swelling and tenderness of the left upper arm. Radiography revealed periosteal mass without fluid-fluid levels. On performing open biopsy, the tumor showed hypercellular proliferation of uniform spindle to epithelioid cells with brisk mitotic activity (up to 12/2 mm2) and lace-like osteoid formation, which was diagnosed as a high-grade surface osteosarcoma. After one course of chemotherapy using adriamycin and cisplatin, peripheral sclerosis was conspicuous, which led to pathological review and revision of diagnosis as "possibly osteoblastoma." The patient was disease-free for 4 years after marginal resection and curettage. Retrospective nanopore DNA sequencing unexpectedly detected a PAFAH1B1::USP6 rearrangement. The fusion gene was further validated using reverse transcription-polymerase chain reaction and the diagnosis was revised to ABC. Chromothripsis involving chromosome 17 has also been identified. Methylation analysis classified the present tumor as an ABC or non-ossifying fibroma using t-distributed stochastic neighbor embedding and unsupervised hierarchical clustering. This case report highlights the utility of nanopore DNA sequencing for soft tissue and bone tumor diagnosis.

Exploring the effects of taurolidine on tumor weight and microvessel density in a murine model of osteosarcoma.

Background: Osteosarcoma is the most common malignant primary bone tumor. The prognosis for patients with disseminated disease remains very poor despite recent advancements in chemotherapy. Moreover, current treatment regimens bear a significant risk of serious side effects. Thus, there is an unmet clinical need for effective therapies with improved safety profiles. Taurolidine is an antibacterial agent that has been shown to induce cell death in different types of cancer cell lines. Methods: In this study, we examined both the antineoplastic and antiangiogenic effects of taurolidine in animal models of osteosarcoma. K7M2 murine osteosarcoma cells were injected, both intramuscular and intraperitoneal, into 60 BALB/c mice on day zero. Animals were then randomized to receive treatment with taurolidine 2% (800 mg/kg), taurolidine 1% (400 mg/kg), or NaCl 0.9% control for seven days by intravenous or intraperitoneal administration. Results: After 35 days, mice were euthanized, and the tumors were harvested for analysis. Eighteen mice were excluded from the analysis due to complications. Body weight was significantly lower in the 2% taurolidine intraperitoneal treatment group from day 9 to 21, consistent with elevated mortality in this group. Intraperitoneal tumor weight was significantly lower in the 1% (p = 0.003) and 2% (p = 0.006) intraperitoneal taurolidine treatment groups compared to the control. No antineoplastic effects were observed on intramuscular tumors or for intravenous administration of taurolidine. There were no significant differences in microvessel density or mitotic rate between treatment groups. Reduced body weight and elevated mortality in the 2% taurolidine intraperitoneal group suggest that the lower 1% dose is preferable. Conclusions: In conclusion, there is no evidence of antiangiogenic activity, and the antitumor effects of taurolidine on osteosarcoma observed in this study are limited. Moreover, its toxic profile grants further evaluation. Given these observations, further research is necessary to refine the use of taurolidine in osteosarcoma treatment.

The whole transcriptome analysis using FFPE and fresh tissue samples identifies the molecular fingerprint of osteosarcoma.

Osteosarcoma is a form of bone cancer that predominantly impacts osteoblasts, the cells responsible for creating fresh bone tissue. Typical indications include bone pain, inflammation, sensitivity, mobility constraints, and fractures. Utilising imaging techniques such as X-rays, MRI scans, and CT scans can provide insights into the size and location of the tumour. Additionally, a biopsy is employed to confirm the diagnosis. Analysing genes with distinct expression patterns unique to osteosarcoma can be valuable for early detection and the development of effective treatment approaches. In this research, we comprehensively examined the entire transcriptome and pinpointed genes with altered expression profiles specific to osteosarcoma. The study mainly aimed to identify the molecular fingerprint of osteosarcoma. In this study, we processed 90 FFPE samples from PathWest with an almost equal number of osteosarcoma and healthy tissues. RNA was extracted from Paraffin-embedded tissue; RNA was sequenced, the sequencing data was analysed, and gene expression was compared to the healthy samples of the same patients. Differentially expressed genes in osteosarcoma-derived samples were identified, and the functions of those genes were explored. This result was combined with our previous studies based on FFPE and fresh samples to perform a meta-analysis. We identified 1,500 identical differentially expressed genes in PathWest osteosarcoma samples compared to normal tissue samples of the same patients. Meta-analysis with combined fresh tissue samples identified 530 differentially expressed genes. IFITM5, MMP13, PANX3, and MAGEA6 were some of the most overexpressed genes in osteosarcoma samples, while SLC4A1, HBA1, HBB, AQP7 genes were some of the top downregulated genes. Through the meta-analysis, 530 differentially expressed genes were identified to be identical among FFPE (105 FFPE samples) and 36 fresh bone samples. Deconvolution analysis with single-cell RNAseq data confirmed the presence of specific cell clusters in FFPE samples. We propose these 530 DEGs as a molecular fingerprint of osteosarcoma.