HOXB5 promotes the progression and metastasis of osteosarcoma cells by activating the JAK2/STAT3 signalling pathway.

Objective: To investigate the involvement of the homeobox gene B5 (HOXB5) in the progression and metastasis of osteosarcoma. Methods: The expression of HOXB5 in human osteosarcoma tissues and its correlation with clinical indicators were investigated using bioinformatics analysis and immunohistochemical labelling. Human osteosarcoma cells (HOS, MG63, U2OS, and Saos-2) and normal human osteoblasts (hFOB1.19) were cultivated. The expression of HOXB5 in these cells was detected using western blotting (WB) and RT‒PCR. Two cell lines exhibiting elevated HOXB5 expression were chosen and divided into three groups: the blank group (mock), control group (control) and transfection group (shHOXB5). The transfection group was infected with lentivirus expressing shRNAs targeting HOXB5. The transfection efficiency was detected by WB. Cell proliferation suppression was measured by CCK-8 and 5-ethynyl-2'-deoxyuridine (EdU) assays; the percentage of apoptotic cells was determined by flow cytometry; and cell migration and invasion were detected via the Transwell chamber test. WB was utilized to determine the protein expression of genes linked to metastasis (MMP2, MMP9), apoptosis (Bax, Bcl-2), and the JAK2/STAT3 pathway (JAK2, p-JAK2, STAT3, p-STAT3). Results: In osteosarcoma tissues, HOXB5 expression was elevated and strongly correlated with distant metastasis. Silencing HOXB5 reduced the proliferation, migration and invasion of osteosarcoma cells; prevented the progression and metastasis of tumours in tumour-bearing nude mice; and reduced the activation of key proteins in the JAK2/STAT3 signalling pathway. Conclusion: Through the JAK2/STAT3 signalling pathway, HOXB5 plays a crucial role in the malignant progression of osteosarcoma and is a promising target for osteosarcoma treatment.

Anti-Her2 affibody-decorated arsenene nanosheets induce ferroptosis through depleting intracellular GSH to overcome cisplatin resistance.

Ferroptosis, a form of regulated cell death induced by excessive accumulation of reactive oxygen species and lipid peroxidation, has recently attracted extensive attention due to its ability to effectively suppress tumors and overcome drug resistance. Unlike previously reported metal nanomaterials that induce ferroptosis via the Fenton reaction, arsenene nanosheets can effectively deplete intracellular glutathione and then induce ferroptosis by inhibiting glutathione peroxidase 4. In this study, we designed target-modified arsenene nanosheets loaded with cisplatin (Her2-ANs@CDDP), which are capable of selective uptake by tumor cells. Her2-ANs@CDDP promotes both apoptosis and ferroptosis through a reciprocal cascade reaction between cisplatin and the carrier, respectively, and we demonstrate that it can significantly inhibit the activity of drug-resistant cells. Arsenene nanosheets kill drug-resistant tumor cells by inducing ferroptosis and restoring the sensitivity of drug-resistant cells to cisplatin. Cisplatin-loaded arsenene nanosheets can be prepared simply, and exert synergistic effects that overcome drug resistance. They show great potential for applications in the clinical treatment of chemotherapy-insensitive osteosarcoma, expanding the uses of arsenic in the treatment of solid tumors.

LPS combined with CD47mAb enhances the anti­osteosarcoma ability of macrophages.

Macrophages are abundant in tumor tissues, and they affect the biological properties of tumor cells. The present findings indicated that osteosarcoma (OS) has a high proportion of tumor-promoting M2 macrophages. The CD47 protein can aid tumor cells in their immunological escape. It was identified that CD47 protein is abundant in both clinical OS tissues and OS cell lines. Lipopolysaccharide (LPS) is an activator of Toll-like receptor 4 present on the surface of macrophages, and it induces the polarization towards a pro-inflammatory phenotype; and macrophages of pro-inflammatory phenotype may present antitumor potential. CD47 monoclonal antibody (CD47mAb) can block the CD47-SIRPα signaling pathway, thus enhancing the antitumor ability of macrophages. Immunofluorescence staining confirmed that OS was rich in CD47 protein and M2 macrophages. In the present study, the antitumor potential of macrophages activated using LPS combined with the CD47mAb was assessed. LPS combined with CD47mAb greatly improved macrophages' capacity to phagocytize OS cells, according to the laser confocal experiments and flow cytometry. Furthermore, cell proliferation analysis, cell migration assay and apoptosis determination confirmed LPS-polarized macrophages might efficiently suppress OS cells growth and migration while promoting apoptosis. Taken together, the results of present study demonstrated that LPS combined with CD47mAb enhanced the anti-osteosarcoma ability of macrophages.

Construction of Osteosarcoma Diagnosis Model by Random Forest and Artificial Neural Network.

Osteosarcoma accounts for 28% of primary bone malignancies in adults and up to 56% in children and adolescents (<20 years). However, early diagnosis and treatment are still inadequate, and new improvements are still needed. Missed diagnoses exist due to fewer traditional diagnostic methods, and clinical symptoms are often already present before diagnosis. This study aimed to develop novel and efficient predictive models for the diagnosis of osteosarcoma and to identify potential targets for exploring osteosarcoma markers. First, osteosarcoma and normal tissue expression microarray datasets were downloaded from the Gene Expression Omnibus (GEO). Then we screened the differentially expressed genes (DEGs) in the osteosarcoma and normal groups in the training group. Next, in order to explore the biologically relevant role of DEGs, Metascape and enrichment analyses were also performed on DEGs. The "randomForest" and "neuralnet" packages in R software were used to select representative genes and construct diagnostic models for osteosarcoma. The next step is to validate the model of the artificial neural network. Then, we performed an immune infiltration analysis by using the training set data. Finally, we constructed a prognostic model using representative genes for prognostic analysis. The copy number of osteosarcoma was also analyzed. A random forest classifier identified nine representative genes (ANK1, TGFBR3, TNFRSF21, HSPB8, ITGA7, RHD, AASS, GREM2, NFASC). HSPB8, RHD, AASS, and NFASC were genes we identified that have not been previously reported to be associated with osteosarcoma. The osteosarcoma diagnostic model we constructed has good performance with areas under the curves (AUCs) of 1 and 0.987 in the training and validation groups, respectively. This study opens new horizons for the early diagnosis of osteosarcoma and provides representative markers for the future treatment of osteosarcoma. This is the first study to pioneer the establishment of a genetic diagnosis model for osteosarcoma and advance the development of osteosarcoma diagnosis and treatment.

Reconstruction of Tumor-Induced Pelvic Defects With Customized, Three-Dimensional Printed Prostheses.

Background: Reconstruction of pelvis girdle stability after tumor-induced hemipelvectomy remains challenging. We surgically treated 13 patients with custom-made, three-dimensional printed hemipelvic prostheses. We aim to identify the preliminary outcomes for patients who have been managed with more mixed regions of prosthetic pelvic reconstruction and the feasibility of two reconstructive systems. Methods: Seven male patients and 6 female patients treated at our center between January 2019 and May 2021 were included. There were 11 primary sarcomas and 2 solitary bone metastases. After en bloc tumor resection, two types of personalized, three-dimensional printed prostheses were fixed to restore the stability and rebuild the load transfer. The position of the reconstructed hemipelvis was evaluated on an anteroposterior plain radiograph. The complications and outcomes were traced. One amputation specimen was discovered through histological analysis of the porous structure. Results: The operative duration was 467 ± 144 min, and the blood loss was 3,119 ± 662 ml. During a follow-up of 22.4 ± 8.5 months, two patients had delayed wound healing and one had a second-stage flap transfer. One patient with osteosarcoma died of pulmonary metastasis 27 months after surgery. Two patients with marginal resection suffered from local recurrence and had extra surgeries. One patient had traumatic hip dislocation 2 months after surgery and manipulative reduction was performed. The acetabular inclination of the affected side was 42.2 ± 4.3°, compared with 42.1 ± 3.9° on the contralateral side. The horizontal distance between the center of the femoral head and the middle vertical line was 10.4 ± 0.6 cm, while the reconstructed side was 9.8 ± 0.8 cm. No significant difference in acetabular position after surgery was found (p > 0.05). The amputation specimen harvested from one patient with local recurrence demonstrated bone and soft tissue ingrowth within the three-dimensional printed trabecular structure. Walking ability was preserved in all patients who are still alive and no prosthesis-related complications occurred. The MSTS score was 22.0 ± 3.7. Conclusions: Both types of custom-made, three-dimensional printed prostheses manifested excellent precision, mechanical stability, and promising functional rehabilitation. The porous structure exhibited favorable histocompatibility to facilitate the ingrowth of bone and soft tissue.

Case Report: 3D-Printed Prosthesis for Limb Salvage and Joint Preservation After Tibial Sarcoma Resection.

Introduction: Reconstruction of massive tibial defects in ankle joint-preserving surgery remains challenging though biological and prosthetic methods have been attempted. We surgically treated a patient with only 18-mm distal tibia remaining and reconstructed with a unique three-dimensional printed prosthesis. Case Presentation Intervention and Outcomes: A 36-year-old male presented to our clinic with complaints of gradually swelling left calf and palpable painless mass for five months. Imageological exam indicated a lesion spanning the entire length of the tibia and surrounding the vascular plexus. Diagnosis of chondrosarcoma was confirmed by biopsy. Amputation was initially recommended but rejected, thus a novel one-step limb-salvage procedure was performed. After en-bloc tumor resection and blood supply rebuilding, a customized, three-dimensional printed prosthesis with porous interface was fixed that connected the tumor knee prosthesis and distal ultra-small bone segment. During a 16-month follow-up, no soft tissue or prosthesis-related complications occurred. The patient was alive with no sign of recurrence or metastasis. Walking ability and full tibiotalar range of motion were preserved. Conclusions: Custom-made, three-dimensional printed prosthesis manifested excellent mechanical stability during the follow-up in this joint-preserving surgery. Further investigation of the durability and rate of long-term complications is needed to introduce to routine clinical practice.

Pharmacodynamics and pharmacokinetics of PLGA-based doxorubicin-loaded implants for tumor therapy.

The traditional systemic chemotherapy through intravenous infusion of doxorubicin (DOX) has many side effects. The aim of this study was to develop a PLGA-based DOX-loaded implant and to evaluate the efficacy and drug metabolism distribution of the implant in intratumoral chemotherapy for osteosarcoma (OS). In this study, implants containing DOX, poly(d,l-lactide-co-glycolide), and polyethylene glycol 4000 were prepared by melt-molding method. Then, the antitumor activity and systemic drug distribution of the implants were tested in a K7M2 OS bearing mouse model. The scanning electron microscope images showed that DOX was uniformly dispersed in the polymer matrix. Both the in vitro and in vivo release profiles of implants are characterized by three-phase release. Implantation of DOX-loaded implants into tumors can inhibit tumor growth in a dose-dependent manner. The pharmacokinetic behavior shows that intratumor chemotherapy through implants has a much higher drug concentration in tumors than in normal tissues, which may be the reason for improving antitumor activity and reducing systemic side effects. In summary, the drug release of the implants prepared in this study is sustained and stable, which promotes long-term local accumulation of drugs in tumors, improves the efficacy of chemotherapy and has low toxicity to normal tissues.

Reconstruction with 3D-printed prostheses after type I + II + III internal hemipelvectomy: Finite element analysis and preliminary outcomes.

Background: Prosthetic reconstruction after type I + II+ III internal hemipelvectomy remains challenging due to the lack of osseointegration and presence of giant shear force at the sacroiliac joint. The purpose of this study was to evaluate the biomechanical properties of the novel 3D-printed, custom-made prosthesis with pedicle screw-rod system and sacral tray using finite element analysis. Methods: Four models that included one intact pelvis were established for validation. Forces of 500 N and 2,000 N were applied, respectively, to simulate static bipedal standing and the most loaded condition during a gait cycle. Biomechanical analysis was performed, and the results were compared; the preliminary outcomes of four patients were recorded. Results: For the reconstructed hemipelvis, stress was mainly concentrated on the sacral screws, bone-prosthesis interface, and upper endplate of the L5 vertebra. The optimization of the design with the sacral tray structure could decrease the peak stress of the sacral screws by 18.6%, while the maximal stress of the prosthesis increased by 60.7%. The addition of the lumbosacral pedicle-rod system further alleviated stress of the sacral screws and prosthesis by 30.2% and 19.4%, respectively. The site of peak stress was contemporaneously transferred to the connecting rods within an elastic range. In the retrospective clinical study, four patients who had undergone prosthetic reconstruction were included. During a follow-up of 16.6 ± 7.5 months, the walking ability was found preserved in all patients who are still alive and no prosthesis-related complications had occurred except for one hip dislocation. The Musculoskeletal Tumor Society (MSTS) score was found to be 19.5 ± 2.9. Conclusion: The novel reconstructive system yielded favorable biomechanical characteristics and demonstrated promising preliminary outcomes. The method can be used as a reference for reconstruction after type I + II + III hemipelvectomy.

Cisplatin inhibits the proliferation of Saos-2 osteosarcoma cells via the miR-376c/TGFA pathway.

The transforming growth factor alpha (TGFA) gene is involved in the proliferation and metastasis of various tumors, but its role in cell sensitivity to cisplatin chemotherapy is unclear. In this study, we investigated the mechanism underlying inhibitory effects of cisplatin on growth and proliferation of osteosarcoma cells. Osteosarcoma and normal skeletal muscle tissues were collected from 26 patients by biopsy. TGFA was silenced or overexpressed in Saos-2 osteosarcoma cells by transfection with TGFA-shRNA or TGFA ORF clone, respectively. MiR-376c was inhibited or overexpressed by transfection of Saos-2 cells with miR-376c sponge or miR-376c mimics, respectively. Cell growth was analyzed by MTT assay and cell proliferation by BrdU assay. MiR-376c and TGFA mRNA expression was detected by quantitative reverse transcription PCR and TGFA protein expression by Western blot. The target relationship between miR-376c and TGFA was assessed by luciferase reporter assay. Both in osteosarcoma tissues and Saos-2 cells, miR-376c expression was significantly decreased and TGFA mRNA expression was significantly increased compared with control. Transfection of Saos-2 cells with TGFA-shRNA silenced TGFA expression and significantly inhibited cell growth and proliferation. TGFA mRNA and protein expression in Saos-2 cells significantly decreased with increasing cisplatin concentrations (2.5-10 mg/L). Transfection with TGFA ORF clone reversed the inhibitory effects of cisplatin on Saos-2 cell proliferation. Compared with cisplatin (10 mg/L) treatment alone, the combined treatment with cisplatin and miR-376c mimics inhibited the proliferation of Saos-2 cells more significantly. MiR-376c suppressed TGFA expression by directly interacting with its 3' UTR region. Overall, cisplatin inhibited the proliferation of Saos-2 cells by upregulating miR-376c and downregulating TGFA expression.

Knockdown of hsa_circ_0037658 inhibits the progression of osteoarthritis via inducing autophagy.

Osteoarthritis (OA) is a chronic musculoskeletal degeneration disease that can result in chronic pain and functional disability. Circular RNAs (CirRNAs) are known to be involved in OA. It was reported that hsa_circ_0037658 was notably upregulated in OA tissues; however, the biological role of hsa_circ_0037658 in OA remains unclear. To investigate the function of hsa_circ_0037658 in OA, CHON-001 cells were treated with IL-1ß. The effect of hsa_circ_0037658 knockdown on cell growth was tested by CCK-8 and immunofluorescence staining. In addition, the correlation between hsa_circ_0037658 and autophagy was explored by LC3 staining and western blot. The results indicated that hsa_circ_0037658 was significantly upregulated in IL-1ß-treated CHON-001 cells. The silencing of hsa_circ_0037658 could protect CHON-001 cell injury against IL-1ß. Moreover, hsa_circ_0037658 shRNA reversed IL-1ß-induced cell growth inhibition via inducing cell autophagy. Furthermore, knockdown of hsa_circ_0037658 notably alleviated the symptom of OA in vivo. To sum up, knockdown of hsa_circ_0037658 suppressed the progression of OA via inducing autophagy. Thus, hsa_circ_0037658 might serve as a potential target for the treatment of OA.

Cold atmospheric plasma­activated Ringer's solution inhibits the proliferation of osteosarcoma cells through the mitochondrial apoptosis pathway.

The present study aimed to investigate the effects of cold atmospheric plasma (CAP)­activated Ringer's solution on osteosarcoma cell lines MG63 and U2OS, and to identify the molecular mechanism underlying these effects. CAP­activated Ringer's solution was used to treat osteosarcoma cell lines MG63 and U2OS for 30 min. Cell viability was measured using the MTT method. The apoptosis rate was detected using Annexin­V and propidium iodide. The expression levels of cytochrome c, caspase­3 and polyADP ribose polymerase (PARP) in MG63 cells were analyzed via western blotting. The change in mitochondrial membrane potential was detected via the JC­1 dye method and verified by the level of reactive oxygen species (ROS). CAP­activated Ringer's solution inhibited the proliferation of MG63 and U2OS cells in a dose­ and time­dependent manner. Furthermore, CAP­activated Ringer's solution induced the apoptosis of MG63 cells, increased the intracellular ROS level, decreased the mitochondrial membrane potential level, and induced the release of cytochrome c. CAP­activated Ringer's solution inhibits osteosarcoma cell proliferation through intracellular ROS­mediated mitochondrial apoptosis.