The clinical effectiveness and safety of Zone III REBOA for resection of sacropelvic tumors in patients older than 70 years.

BACKGROUND: REBOA is a method used to manage bleeding during surgery involving sacropelvic tumors. Nevertheless, studies on the use of REBOA among elderly people are lacking. The aim of this research was to investigate the efficacy and safety of Zone III REBOA in patients aged more than 70 years. METHODS: A comparative study was conducted using case-control methods. A group of patients, referred to as Group A, who were younger than 70 years was identified and paired with a comparable group of patients, known as Group B, who were older than 70 years. Continuous monitoring of physiological parameters was conducted, and blood samples were collected at consistent intervals. RESULTS: Totally, 188 participants were enrolled and received REBOA. Among the 188 patients, seventeen were aged more than 70 years. By implementing REBOA, the average amount of blood loss was only 1427 ml. Experiments were also conducted to compare Group A and Group B. No notable differences were observed in terms of demographic variables, systolic blood pressure (SBP), arterial pH, lactate levels, blood creatinine levels, potassium levels, or calcium levels at baseline. Additionally, after the deflation of the REBOA, laboratory test results, which included arterial pH, lactate, potassium concentration, calcium concentration, and blood creatinine concentration, were not significantly different (P > 0.05). CONCLUSION: This study indicated that in selected patients aged more than 70 years can achieve satisfactory hemodynamic and metabolic stability with Zone III REBOA. LEVEL OF EVIDENCE: Therapeutic study, Level III.

Clinical outcomes in patients with neurological disorders following periacetabular tumor removal and endoprosthetic reconstruction of the hemipelvis.

Background: Surgical treatment of musculoskeletal tumors in the periacetabular region present extremely difficult due to the complex anatomy and need for reconstruction. Orthopedic surgeons face more difficulties in patients with neurological conditions, which can cause increased muscle tone, an elevated risk of fractures, and compromised bone quality. There is limited evidence regarding endoprosthetic reconstruction for periacetabular tumors in individuals with neurological disorders. Methods: We conducted a single-center retrospective study to examine the outcomes of patients with preexisting neurological conditions who underwent surgery to remove periacetabular tumors and who underwent endoprosthesis reconstruction. Clinical presentation, detailed neurological conditions, complications, and functional outcomes were studied. Results: Sixteen out of the 838 patients were identified (1.91%), with a mean follow-up time of 33 months. The primary neurological conditions encompassed Parkinson's disease, Alzheimer's disease, dementia, and cerebral ischemic stroke. Every patient was diagnosed with periacetabular lesions that were either primary or oligometastatic. They underwent tumor resection and subsequently received endoprosthetic reconstruction of the hemipelvis. Three patients developed metastasis lesions later, and two patients experienced tumor recurrence. Five cases experienced hip dislocation-one with periprosthetic fracture and one with surgical site infection. The position of the prosthetic rotating center was not correlated with dislocation. The reoperation rate was 31.25%. The cohort of patients all presented with more extended hospital stays and rehabilitation. In 3 patients, the general functional score was good, while in 6 patients, it was fair; in 7 patients, it was regarded as poor. The average MSTS93 score was 49.71%. Conclusion: Endoprosthetic reconstruction after periacetabular tumor resection is an effective way to eliminate tumors and salvage limbs. However, this group of patients has an increased likelihood of secondary surgery, complications, extended hospital stay, and no significant improvement in functional outcomes. Despite the diverse nature of the cohort, it is recommended to consider enhanced soft tissue reconstruction, supervised functional recovery and rehabilitation training.

The outcomes of proximal femur replacement with hemiarthroplasty after tumor resection in individuals with Parkinson's disease.

Background: Patients with neurological disorders often experience a high incidence of postoperative complications following proximal femur replacement (PFR) surgery. The orthopaedist faces a significant difficulty in treating Parkinson's disease (PD) because of the weakened bone condition, excessive muscle tension, and increased risk of fractures. The objective of this research is to assess the impact of PD on PFR following tumor removal. Methods: A retrospective study was conducted from 2010 to 2020, focusing on a solitary institution, analyzing 9 patients diagnosed with PD who underwent PFR with hemiarthroplasty as a result of tumor removal. The study consists of 2 men and 7 women, with an average age of 71 (SD, 12) years. We assessed the outcomes after surgery in terms of pain management, quality of life, functional ability, occurrence of complications, and survival durations. Results: All nine patients underwent planned surgeries. Intraoperative complications was not observed. The average length of the follow-up period was 24 (SD, 20) months, ranging from 8 to 72 months. Despite the fact that 8 patients passed away due to tumor progression, the endoprostheses were still well at that point. The preoperative VAS score of 7 (SD, 1.87) decreased to a postoperative score of 2 (SD, 1.32). The KPS was improved to73 (SD, 7) from 52 (SD, 14), postoperatively. Post-surgery, there were notable enhancements in both pain levels and the overall quality of life scores. Following the surgical procedure, individuals are able to ambulate steadily, resuming their regular daily routines. Living patients had an average MSTS score of 21 (SD, 2.5), ranging from 17 to 25. In total, there were four (44.4%) patients suffered complications after surgery, comprising of one wound dehiscence, one prosthetic fracture, one hip dislocation, and one local recurrence. Conclusions: Significant improvements in function and pain relief can be achieved through PFR with hemiarthroplasty following tumor removal in patients with PD. The implementation of thorough preparation and carefull nursing results in reduced complications and improved outcomes in PD patients.

Surgical results and quality of life after single-stage posterior transpedicular approach for circumferential epidural decompression in patients with thoracolumbar spine metastasis.

Objective: The primary aim of this study was to evaluate the effect of palliative surgery using posterior transpedicular approach (PTA) with posterior instrumentation on pain response and quality of life (QoL) in patients with metastatic thoracic and lumbar tumors. Methods: From 2018 to 2019, 39 patients with metastatic thoracic and/or lumbar tumors were prospectively enrolled to measure the reduction in pain and the changes in QoL after surgical decompression with posterior instrumentation via PTA. The patient group was composed of 27 men and 12 women with a mean age of 60 years (range, 28 to 92 years). Pain response was measured using the visual analog scale (VAS) and neurologic status was evaluated using Frankel grades. QoL was assessed with use of the EORCT QLQ-BM22 questionnaire before surgery (baseline) and at 1-, 3-, 6-, and 12-month after surgery. The survival times of all the patients were also collected. Results: All patients showed either an improvement or a similar pain level after surgery, which the VAS score decreased from 7.10 ± 2.22 preoperatively to 3.10 ± 2.15 one month postoperatively (P<0.05). 19 patients (48.7%, 19/39) showed neurological function improvement postoperatively. Among the 19 patients, 7 cases improved from Frankel grade C to D, 5 cases from grade C to E, and 7 cases from grade D to E. Another 20 patients still have the same Frankel grade postoperatively, however, most of them improved clinically. The QoL improvement of the patients was also evident after treatment. Paired-samples T-test examination of the postoperative scores showed a significant improvement in terms of pain location, pain severity and performance status (P<0.01). Compared with the preoperative score, the 1-month postoperative score of functional interference was significantly improved (63.6 vs. 34.5, P<0.01). There were no significant changes in social or psychological functioning. Three patients experienced cerebrospinal fluid leakage postoperatively, and they were all successfully managed by lying flat without a pillow. One patient experienced rod breakage, at 10 months after surgery. All the patients were alive at 3 months; however, 7 patients died within 3 to 6 months, and another 9 patients died from the disease within 6 to 12 months. Conclusions: The present feasibility study found that the application of the PTA for decompression and fusion in patients with spinal metastases is beneficial for achieving prompt and sustained pain relief, reducing neurologic deficits and improving functional outcomes, health utilities, and HRQoL.

Chordoma recruits and polarizes tumor-associated macrophages via secreting CCL5 to promote malignant progression.

BACKGROUND: Chordoma is an extremely rare, locally aggressive malignant bone tumor originating from undifferentiated embryonic remnants. There are no effective therapeutic strategies for chordoma. Herein, we aimed to explore cellular interactions within the chordoma immune microenvironment and provide new therapeutic targets. METHODS: Spectrum flow cytometry and multiplex immunofluorescence (IF) staining were used to investigate the immune microenvironment of chordoma. Cell Counting Kit-8, Edu, clone formation, Transwell, and healing assays were used to validate tumor functions. Flow cytometry and Transwell assays were used to analyze macrophage phenotype and chemotaxis alterations. Immunohistochemistry, IF, western blot, PCR, and ELISA assays were used to analyze molecular expression. An organoid model and a xenograft mouse model were constructed to investigate the efficacy of maraviroc (MVC). RESULTS: The chordoma immune microenvironment landscape was characterized, and we observed that chordoma exhibits a typical immune exclusion phenotype. However, macrophages infiltrating the tumor zone were also noted. Through functional assays, we demonstrated that chordoma-secreted CCL5 significantly promoted malignancy progression, macrophage recruitment, and M2 polarization. In turn, M2 macrophages markedly enhanced the proliferation, invasion, and migration viability of chordoma. CCL5 knockdown and MVC (CCL5/CCR5 inhibitor) treatment both significantly inhibited chordoma malignant progression and M2 macrophage polarization. We established chordoma patient-derived organoids, wherein MVC exhibited antitumor effects, especially in patient 4, with robust killing effect. MVC inhibits chordoma growth and lung metastasis in vivo. CONCLUSIONS: Our study implicates that the CCL5-CCR5 axis plays an important role in the malignant progression of chordoma and the regulation of macrophages, and that the CCL5-CCR5 axis is a potential therapeutic target in chordoma.

The malignancy of chordomas is enhanced via a circTLK1/miR-16-5p/Smad3 positive feedback axis.

CircRNAs play crucial roles in various malignancies via an increasing number of reported regulatory mechanisms, including the classic sponging mechanism between circRNAs and micro RNAs (miRNAs). We performed bioinformatic analyses and identified circTLK1 as a regulator of malignant chordoma progression. Moreover, we observed that circTLK1 showed high expression in chordoma cells and tissues, while circTLK1 interference suppressed chordoma cell proliferation and invasion. In addition, circTLK1 directly interacted with miR-16-5p, which has previously been shown to repress chordoma, and circTLK1 knockdown suppressed Smad3 expression. Chromatin immunoprecipitation sequencing further demonstrated that Smad3 acts as a positive regulator by interacting with TLK1, thereby mediating the circTLK1/miR-16-5p/Smad3 positive feedback axis. Taken together, our findings suggested that the disruption of the circTLK1/miR-16-5p/Smad3 positive feedback pathway, particularly via the Smad3 inhibitor SIS3, could be a promising therapeutic strategy.

The COPS3-FOXO3 positive feedback loop regulates autophagy to promote cisplatin resistance in osteosarcoma.

Chemotherapy is an important treatment modality for osteosarcoma (OS), but the development of chemoresistance limits the therapeutic efficacy of OS and results in a poor prognosis. Thus, a better understanding of the mechanisms underlying chemoresistance in OS is essential. We previously demonstrated that COPS3/CSN3 (COP9 signalosome subunit 3) functions as an oncogene to promote OS cells lung metastasis, which is closely related to chemoresistance. Here, we showed that COPS3 was significantly upregulated in OS tissues with poor response to preoperative chemotherapy. Moreover, COPS3 depletion made OS cells more sensitive to cisplatin treatment in vitro and in vivo, implicating COPS3 as a driver of cisplatin resistance. Mechanistic investigations showed that COPS3 induced a cytoprotective macroautophagy/autophagy in response to cisplatin. Specifically, we identified FOXO3 as a critical target of COPS3, as high expression of COPS3 enhanced the nuclear abundance of FOXO3 and increased the expression of FOXO3-responsive genes, promoting autophagosome formation and maturation. In turn, FOXO3 regulated COPS3 levels by inhibiting ubiquitin-mediated degradation and attenuating SKP2-mediated COPS3 inhibition, cooperatively maintaining a high level of COPS3. In both COPS3-expressing OS cells and a murine xenograft model, inhibition of autophagy could also overcome resistance to cisplatin. Collectively, our results offer insights into the mechanisms of cisplatin resistance and suggest that targeting COPS3-mediated autophagy is a promising therapeutic strategy for overcoming the cisplatin resistance of OS.Abbreviations: 3-MA: 3-methyladenine; BECN1: beclin 1; ChIP: chromatin immunoprecipitation; CHX: cycloheximide; COPS3/CSN3: COP9 signalosome subunit 3; CQ: chloroquine; DEGs: differentially expressed genes; FOXO3: forkhead box O3; GFP: green fluorescent protein; IC50: 50% inhibitory concentration; LAMP1: lysosomal associated membrane protein 1; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MTOR: mechanistic target of rapamycin kinase; mRFP: monomeric red fluorescent protein; OS: osteosarcoma; PBS: phosphate-buffered saline; qRT-PCR: quantitative real-time PCR; RAB7: RAB7, member RAS oncogene family; RPS6KB1/p70S6K1: ribosomal protein S6 kinase B1; SEM: standard error of the mean; shRNA: short hairpin RNA; siRNA: small interfering RNA; SKP2: S-phase kinase associated protein 2; TEM: transmission electron microscopy; UPS: ubiquitin-proteasome system.

Molecular subtypes of osteosarcoma classified by cancer stem cell related genes define immunological cell infiltration and patient survival.

Recent studies have shown that tumor stemness has biological significance in tumorigenicity and tumor progression. However, the characteristics of TME immune infiltration in osteosarcoma mediated by the combined effects of multiple cancer stem cell-related genes remain unknown. Methods: In this study, we identified different cancer stem cell-associated subtypes in osteosarcoma based on 25 cancer stem cell-associated genes by consensus clustering analysis, and we comprehensively evaluated the association between these subtypes and immunocytes infiltration in the TME. The cancer stem cell (CSC) score was constructed to quantify the stemness of individual tumors. Results: We performed a comprehensive evaluation of 218 osteosarcoma patients based on 25 cancer stem cell-related genes. Three different cancer stem cells related subtypes were identified, which were related to different biological processes and clinical outcomes. The three subtypes have different TME cells infiltrating characteristics, and CSC Cluster A had a higher level of immunocyte infiltration compared to CSC Cluster B and C. We constructed a scoring system, called the CSC score, to assess the stemness of individual patients. Then we found that the prognosis of patients was predicted by CSC score, and patients with low CSC score had prolonged survival. Further analyses showed that low CSC score was correlated with enhanced immune infiltration. CSC score may predict the effect of immunotherapy, and patients with low CSC score may have better immune response and clinical prognosis. Conclusions: This study demonstrates that there could be three cancer stem cell-associated subtypes in osteosarcoma and that they were associated with different patient prognosis and TME immune infiltration characteristics. CSC score could be used to assess the stemness of individual patients, improve our comprehension of TME characteristics, and direct more effective immune therapy.

PI3K inhibitor impairs tumor progression and enhances sensitivity to anlotinib in anlotinib-resistant osteosarcoma.

Despite recent improvements in the therapeutic management of osteosarcoma (OS), the ongoing challenges in overcoming resistance to tyrosine kinase inhibitors (TKIs) warrant new strategies to improve overall patient survival. In this study, we established four anlotinib-resistant OS cell lines and demonstrated that the mechanism of anlotinib resistance is due to the loss of PTEN and reactivation of the MAPK pathway. Reduced PTEN expression was also observed in tumor samples from patients with OS and lung metastasis. We investigated the effects of an orally active PI3K inhibitor, either alone or in combination with anlotinib, on the progression of resistant cells and a xenograft nude mouse model. Notably, PI3K inhibitor suppressed anlotinib-resistant OS cell proliferation, migration, invasion, and cytoskeleton formation, and induced apoptosis. Combined treatment with anlotinib augmented these effects by restoring PTEN expression and decreasing MAPK and PI3K/AKT/mTOR signaling. PI3K inhibitors could reverse anlotinib resistance in OS, limiting OS cell development in combination with anlotinib. Our findings rationalize further studies on the applications of PI3K inhibitors that can be clinically used in anlotinib-refractory OS management.

Immune-Related LncRNAs Affect the Prognosis of Osteosarcoma, Which Are Related to the Tumor Immune Microenvironment.

Background: Abnormal expression of lncRNA is closely related to the occurrence and metastasis of osteosarcoma. The tumor immune microenvironment (TIM) is considered to be an important factor affecting the prognosis and treatment of osteosarcoma. This study aims to explore the effect of immune-related lncRNAs (IRLs) on the prognosis of osteosarcoma and its relationship with the TIM. Methods: Ninety-five osteosarcoma samples from the TARGET database were included. Iterative LASSO regression and multivariate Cox regression analysis were used to screen the IRLs signature with the optimal AUC. The predict function was used to calculate the risk score and divide osteosarcoma into a high-risk group and low-risk group based on the optimal cut-off value of the risk score. The lncRNAs in IRLs signature that affect metastasis were screened for in vitro validation. Single sample gene set enrichment analysis (ssGSEA) and ESTIMATE algorithms were used to evaluate the role of TIM in the influence of IRLs on osteosarcoma prognosis. Results: Ten IRLs constituted the IRLs signature, with an AUC of 0.96. The recurrence and metastasis rates of osteosarcoma in the high-risk group were higher than those in the low-risk group. In vitro experiments showed that knockdown of lncRNA (AC006033.2) could increase the proliferation, migration, and invasion of osteosarcoma. ssGSEA and ESTIMATE results showed that the immune cell content and immune score in the low-risk group were generally higher than those in the high-risk group. In addition, the expression levels of immune escape-related genes were higher in the high-risk group. Conclusion: The IRLs signature is a reliable biomarker for the prognosis of osteosarcoma, and they alter the prognosis of osteosarcoma. In addition, IRLs signature and patient prognosis may be related to TIM in osteosarcoma. The higher the content of immune cells in the TIM of osteosarcoma, the lower the risk score of patients and the better the prognosis. The higher the expression of immune escape-related genes, the lower the risk score of patients and the better the prognosis.

Chloroquine suppresses proliferation and invasion and induces apoptosis of osteosarcoma cells associated with inhibition of phosphorylation of STAT3.

BACKGROUND: Osteosarcoma (OS) is characterized by a high rate of metastasis. It has been found that tumor cells can bypass apoptosis which leads to an uncontrolled proliferation, but chloroquine (CQ) can have an effect on the tumors by inducing apoptosis. We aimed to explore the effects and the hypothetical mechanism of CQ effects on OS. METHODS: We first estimated the CQ effects on proliferation, apoptosis, migration, invasion, and lamellipodia formation of OS cells. Mice bearing xenograft model were used to test the anti-tumor growth and lung metastasis effects of CQ in OS. Western blot and immunohistochemistry were used to explore the mechanism of CQ effects and the association between p-STAT3 expression and lung metastasis of OS patients. RESULTS: CQ induces the apoptosis and suppressed the viability, proliferation, migration, invasion, and lamellipodia formation of OS cells in vitro. In vivo experiments demonstrated that CQ inhibited tumor growth and lung metastasis. CQ induced apoptosis was dependent on the lysosomal inhibition and inhibition of protein turnover. The lung metastasis was associated with the p-STAT3 expression in OS patients. CONCLUSION: CQ inhibited progression of OS cells in vitro, and suppressed tumor growth and lung metastasis in vivo. p-STAT3 can be a predictive biomarker for lung metastasis in osteosarcoma patients.

Macrophages-derived exosomal lncRNA LIFR-AS1 promotes osteosarcoma cell progression via miR-29a/NFIA axis.

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor in young people. Tumor-associated macrophages (TAMs) have been reported to play an important role in the development of osteosarcoma. However, the detailed molecular mechanisms remain largely unknown and need to be elucidated. Recently, exosomes have been reported as the crucial mediator between tumor cells and the tumor microenvironment. And a lot of lncRNAs have been reported to act as either oncogenes or tumor suppressors in osteosarcoma. In this research, we aim to explore the role of macrophages-derived exosomal lncRNA in osteosarcoma development and further elucidated the potential molecular mechanisms involved. METHODS: TAMs were differentiated from human mononuclear cells THP-1, and a high-throughput microarray assay was used to analyze the dysregulated lncRNAs and miRNAs in osteosarcoma cells co-cultured with macrophages-derived exosomes. Western blot, qRT-PCR assays, and Dual-luciferase reporter assay were used to verify the interaction among LIFR-AS1, miR-29a, and NFIA. Cck-8, EdU, colony formation assay, wound-healing, and transwell assay were performed to explore the characterize the proliferation and metastasis ability of OS cells. And qPCR, Western blots, immunohistochemistry, and cell immunofluorescence were used to detect the expression of relative genes or proteins. RESULTS: In this study, we found that THP-1-induced macrophage-derived exosomes could facilitate osteosarcoma cell progression both in vitro and in vivo. Then, the results of the high-throughput microarray assay showed that LIFR-AS1 was highly expressed and miR-29a was lowly expressed. Furthermore, LIFR-AS1 was identified as a miR-29a sponge, and NFIA was validated as a direct target of miR-29a. Functional assays demonstrated that knockdown of exosomal LIFR-AS1 could attenuate the promotion effects of macrophages-derived exosomes on osteosarcoma cell progression and miR-29a inhibition could reserve the effect of LIFR-AS1-knockdown exosomes. Correspondingly, NFIA-knockdown could partially reverse the tumor inhibition effect of miR-29a on osteosarcoma cells. CONCLUSIONS: Taken together, macrophages-derived exosomal lncRNA LIFR-AS1 can promote osteosarcoma cell proliferation, invasion, and restrain cell apoptosis via miR-29a/NFIA axis, which can act as a potential novel therapeutic target for osteosarcoma therapy.

The role of tumor-associated macrophages in osteosarcoma progression - therapeutic implications.

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor. Compared with previous treatment modalities, such as amputation, more recent comprehensive treatment modalities based on neoadjuvant chemotherapy combined with limb salvage surgery have improved the survival rates of patients. Osteosarcoma treatment has, however, not further improved in recent years. Therefore, attention has shifted to the tumor microenvironment (TME) in which osteosarcoma cells are embedded. Therapeutic targets in the TME may be key to improving osteosarcoma treatment. Tumor-associated macrophages (TAMs) are the most common immune cells within the TME. TAMs in osteosarcoma may account for over 50% of the immune cells, and may play important roles in tumorigenesis, angiogenesis, immunosuppression, drug resistance and metastasis. Knowledge on the role of TAMs in the development, progression and treatment of osteosarcoma is gradually improving, although different or even opposing opinions still remain. CONCLUSIONS: TAMs may participate in the malignant progression of osteosarcoma through self-polarization, the promotion of blood vessel and lymphatic vessel formation, immunosuppression, and drug resistance. Besides, various immune checkpoint proteins expressed on the surface of TAMs, such as PD-1 and CD47, provide the possibility of the application of immune checkpoint inhibitors. Several clinical trials have been carried out and/or are in progress. Mifamotide and the immune checkpoint inhibitor Camrelizumab were both found to be effective in prolonging progression-free survival. Thus, TAMs may serve as attractive therapeutic targets. Targeting TAMs as a complementary therapy is expected to improve the prognosis of osteosarcoma. Further efforts may be made to identify potential beneficiaries of TAM-targeted therapies.

Constitutive GLI1 expression in chondrosarcoma is regulated by major vault protein via mTOR/S6K1 signaling cascade.

Hedgehog signaling plays a pivotal role in embryonic pattern formation and diverse aspects of the postnatal biological process. Perturbation of the hedgehog pathway and overexpression of GLI1, a downstream transcription factor in the hedgehog pathway, are highly relevant to several malignancies including chondrosarcoma (CS). We previously found that knocking down expression of GLI1 attenuates the disrupted Indian hedgehog (IHH) signal pathway and suppresses cell survival in human CS cells. However, the underlying mechanisms regulating the expression of GLI1 are still unknown. Here, we demonstrated the implication of GLI1 in SMO-independent pathways in CS cells. A GLI1 binding protein, major vault protein (MVP), was identified using the affinity purification method. MVP promoted the nuclear transport and stabilization of GLI1 by compromising the binding affinity of GLI1 with suppressor of fused homolog (SUFU) and increased GLI1 expression via mTOR/S6K1 signaling cascade. Functionally, knockdown of MVP suppressed cell growth and induced apoptosis. Simultaneous inhibition of MVP and GLI1 strongly inhibits the growth of CS in vitro and in vivo. Moreover, IHC results showed that MVP, GLI1, and P-p70S6K1 were highly expressed and positively correlated with each other in 71 human CS tissues. Overall, our findings revealed a novel regulating mechanism for HH-independent GLI1 expression and provide a rationale for combination therapy in patients with advanced CS.

Identification of Potential Therapeutic Targets and Immune Cell Infiltration Characteristics in Osteosarcoma Using Bioinformatics Strategy.

Osteosarcoma is one of the most aggressive malignant bone tumors worldwide. Although great advancements have been made in its treatment owing to the advent of neoadjuvant chemotherapy, the problem of lung metastasis is a major obstacle in the improvement of survival outcomes. Thus, the aim of the present study is to screen novel and key biomarkers, which may act as potential prognostic markers and therapeutic targets in osteosarcoma. We utilized the robust rank aggregation (RRA) method to integrate three osteosarcoma microarray datasets downloaded from the Gene Expression Omnibus (GEO) database, and we identified the robust differentially expressed genes (DEGs) between primary and metastatic osteosarcoma tissues. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to explore the functions of robust DEGs. The results of enrichment analysis showed that the robust DEGs were closely associated with osteosarcoma development and progression. Immune cell infiltration analysis was also conducted by CIBERSORT algorithm, and we found that macrophages are the most principal infiltrating immune cells in osteosarcoma, especially macrophages M0 and M2. Then, the protein-protein interaction network and key modules were constructed by Cytoscape, and 10 hub genes were selected by plugin cytoHubba from the whole network. The survival analysis of hub genes was also carried out based on the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. The integrated bioinformatics analysis was utilized to provide new insight into osteosarcoma development and metastasis and identified EGR1, CXCL10, MYC, and CXCR4 as potential biomarkers for prognosis of osteosarcoma.

Development of a prognostic gene signature based on an immunogenomic infiltration analysis of osteosarcoma.

Osteosarcoma is the most common primary malignant bone tumour predominantly occurring in children and adolescents with a high tendency of local invasion and early metastases. Currently, tumour immune microenvironment (TME) is becoming the focus of studying of malignant tumours.. However, no sound evidence shows a specific immune molecular target in osteosarcoma. We downloaded the gene expression profile and clinical data of osteosarcoma from the TARGET portal, and extracted and normalized via R software. Then, the immune cell infiltration assessed by CIBERSORT and ESTIMATE algorithms. Three survival-related immune cells and immune score were obtained via Kaplan-Meier survival analysis, and 232 immune-related genes were obtained as candidate genes. Enrichment and protein-protein interaction co-expression analyses were performed to identify 13 hub genes. Lastly, a seven gene prognostic signature was identified by univariate and multivariate Cox regression analyses. More importantly, our validations and TIMER algorithm suggested this immune-related prognostic signature a good predictive tool. Our findings have provided novel insights that could demonstrate new targets of immunotherapy in osteosarcoma.

Bone marrow mesenchymal stem cell-derived exosomal miR-206 inhibits osteosarcoma progression by targeting TRA2B.

Osteosarcoma is the most common primary malignant bone tumor in young people. Recently, extracellular vesicles, especially exosomes, have been reported to play an increasingly important role in the development of many types of tumors. In this research, we found that overexpression of transformer 2ß (TRA2B) was associated with tumor progression in osteosarcoma, and TRA2B was the target gene of miR-206, which was downregulated in osteosarcoma tissues. Furthermore, we observed that bone marrow mesenchymal stem cell (BMSC)-derived exosomes could carry and transport miR-206 to osteosarcoma cells. Both in vitro and in vivo results showed that BMSC-derived exosomal miR-206 could inhibit the proliferation, migration and invasion of osteosarcoma cells and induce their apoptosis. Taken together, our study demonstrates that BMSC-derived exosomal miR-206 can be transferred into osteosarcoma cells and inhibit tumor progression by targeting TRA2B, which provides new insight into the molecular mechanism of osteosarcoma and highlights the potential of miR-206 and TRA2B as new therapeutic targets.

miR-100-5p Inhibits Malignant Behavior of Chordoma Cells by Targeting IGF1R.

PURPOSE: Our research aimed to illuminate the role of miR-100-5p in chordoma and potential mechanism. MATERIALS AND METHODS: We used microRNA array analysis to explore differentially expressed miRNAs in chordoma tissue and then verified by qRT-PCR. Cell proliferation and transwell assay were used to evaluate the function of miR-100-5p. Cell apoptosis was analyzed by flow cytometry, and using biological software, we predicted that the insulin-like growth factor 1 receptor (IGF1R) could be the target gene of miR-100-5p, which was then validated by dual luciferase assays and Western blot. RESULTS: miR-100-5p was downregulated in chordoma tissues. Overexpression of miR-100-5p could suppress the growth of chordoma both in vitro and in vivo, and miR-100-5p could inhibit the migration and invasion of chordoma cells partially by suppressing epithelial-mesenchymal transition (EMT). Furthermore, IGF1R was validated as the target gene of miR-100-5p and expressed in most chordoma tissues. CONCLUSION: In conclusion, our results showed that miR-100-5p was lowly expressed in chordoma and inhibited tumor malignant progression by targeting IGF1R.

Macrophages reduce the sensitivity of osteosarcoma to neoadjuvant chemotherapy drugs by secreting Interleukin-1 beta.

Osteosarcoma is a common, highly malignant tumor of the musculoskeletal system in young people. Compared with simple amputation in the past, the application of neoadjuvant chemotherapy significantly improved the 5-year survival rate and limb-salvage rate of tumor patients without metastasis. However, the survival rate of patients with metastatic disease treated with neoadjuvant chemotherapy has remained stagnant over the past 30 years despite repeated attempts of adding neoadjuvant chemotherapy agents into the regimen or enhancing the chemotherapy drug dose. In this study, we revealed that macrophages, stimulated by neoadjuvant chemotherapy agents, could reduce the sensitivity of osteosarcoma cells to the drugs. Furthermore, we found that this phenomenon was strongly related to the secretion of the interleukin-1beta by macrophages. Our findings may provide new ideas for improving the efficiency of neoadjuvant chemotherapy for osteosarcoma.

Insight Into the Role of Autophagy in Osteosarcoma and Its Therapeutic Implication.

Osteosarcoma is an aggressive bone cancer that frequently metastasizes to the lungs. The cytotoxicity of most chemotherapeutics and targeted drugs in the treatment of osteosarcoma is partially lessened. Furthermore, there is a poor response to current chemo- and radiotherapy for both primary lesions and pulmonary metastases of osteosarcoma. There is a clear need to explore promising drug candidates that could improve the efficacy of osteosarcoma treatment. Autophagy, a dynamic and highly conserved catabolic process, has dual roles in promoting cell survival as well as cell death. The role of autophagy has been investigated extensively in different tumor types, and a growing body of research has highlighted the potential value of using autophagy in clinical therapy. Here, we address significant aspects of autophagy in osteosarcoma, including its functions, modulation, and possible therapeutic applications.