Cholic Acid/Glutathione-Assembled Nanofibrils for Stabilizing Pickering Emulsion Biogels.

Achieving the delicate balance required for both emulsion and gel characteristics, while also imparting biological functionality in gelled emulsions, poses a significant challenge. Herein, Pickering emulsion biogels stabilized is reported by novel biological nanofibrils assembled from natural glutathione (GSH) and a tripod cholic acid derivative (TCA) via electrostatic interactions. GSH, composed of tripeptides with carboxyl groups, facilitates the protonation and dissolution of TCA compounds in water and the electrostatic interactions between GSH and TCA trigger nanofibrillar assembly. Fibrous nuclei initially emerge, and the formed mature nanofibrils can generate a stable hydrogel at a low solid concentration. These nanofibrils exhibit efficient emulsifying capability, enabling the preparation of stable Pickering oil-in-water (O/W) emulsion gels with adjustable phase volume ratios. The entangled nanofibrils adsorbed at the oil-water interface restrict droplet movement, imparting viscoelasticity and injectability to the emulsions. Remarkably, the biocompatible nanofibrils and stabilized emulsion gels demonstrate promising scavenging properties against reactive oxygen species (ROS). This strategy may open new scenarios for the design of advanced emulsion gel materials using natural precursors and affordable building blocks for biomedical applications.

The burden of knee osteoarthritis worldwide, regionally, and nationally from 1990 to 2019, along with an analysis of cross-national inequalities.

OBJECTIVE: To describe the disease burden of knee osteoarthritis (KOA) globally, regionally, and in 204 countries by age, sex, and sociodemographic index (SDI) from 1990 to 2019, and to explore cross-national inequalities across SDI. METHODS: The Global Burden of Disease (GBD) 2019 database collected data on KOA worldwide from 1990 to 2019, including prevalence, incidence, years lived with disability (YLDs). The average annual percentage change (AAPC) was used to measure temporal trends. In addition, the inequality slope index and the health concentration index were calculated to quantify the unequal distribution of the burden of KOA across 204 countries worldwide. RESULTS: In 2019, the global age-standardized prevalence rate increased by 7.5% compared with 1990, and the age-standardized incidence rate increased by about 6.2%; The age-standardized YLDs rate increased by about 7.8%. In addition to the Republic of Korea and the United States of America, the disease burden of KOA has increased year by year in other countries around the world. The incidence of KOA was highest at ages 50-59, while the prevalence and rates of YLDs were highest at ages 75-84. The burden of KOA was higher in women than in men. Cross-country inequality suggests that the inequality in the burden of KOA between high SDI and low SDI countries becomes greater, and that countries with high SDI bear a disproportionately high burden. CONCLUSION: The global KOA burden has risen steadily between 1990 and 2019, and cross-national inequality gaps remain large. Targeted measures must therefore be taken to address this inequality and the increasing global KOA disease burden.

miR-223-3p Inhibits Human Osteosarcoma Metastasis and Progression by Directly Targeting CDH6.

Cadherin-6 (CDH6) is aberrantly expressed in cancer and closely associated with tumor progression. However, the functions of CDH6 in human osteosarcoma and the molecular mechanisms underlying CDH6 in osteosarcoma oncogenesis remain poorly understood. In this work, we assessed the role of CDH6 in human osteosarcoma and identified that the expression of CDH6 was closely related with the overall survival and poor prognosis of osteosarcoma patients. MicroRNAs (miRNAs) have been implicated as important epigenetic regulators during the progression of osteosarcoma. Using dual-luciferase reporter assays, we showed that miR-223-3p suppresses CDH6 expression by directly binding to the 3' UTR of CDH6. miR-223-3p overexpression significantly inhibited cell invasion, migration, growth, and proliferation by suppressing the CDH6 expression in vivo and in vitro. Besides, CDH6 overexpression in the miR-223-3p-transfected osteosarcoma cells effectively rescued the inhibition of cell invasion, migration, growth, and proliferation mediated by miR-223-3p. Additionally, Kaplan-Meier analysis suggests that the expression of miR-223-3p predicts favorable clinical outcomes for osteosarcoma patients. Moreover, the expression of miR-223-3p was downregulated in osteosarcoma patients and was negatively associated with the expression of CDH6. Collectively, these data highlight that miR-223-3p/CDH6 axis is an important novel pleiotropic regulator and could early predict the metastatic potential in human osteosarcoma treatments.

The multidisciplinary treatment of osteosarcoma of the proximal tibia: a retrospective study.

BACKGROUND: Survival and reconstruction constitute important challenges in multimodal treatment of osteosarcoma of the proximal tibia. The purpose of this study was to assess the efficacy and prognosis of neoadjuvant chemotherapy and custom-designed endoprosthetic arthroplasty. METHODS: A total of 69 patients with osteosarcoma of the proximal tibia were evaluated, including 43 males and 26 females, treated with multidisciplinary limb-salvage remedy from October 2003 to December 2013. They were at least 12 years old (mean, 20 years; range, 12-57 years). The gap between tumor and main artery/nerve was showed in MRI. Mean follow up was 69.5 months (range, 9-144 months). Kaplan-Meier survival curves were generated to assess prognosis and relapse rate. The initial symptoms and disease duration for each patient were recorded. Correlation analyses were performed for the association of various parameters with prognosis. Functional outcomes were evaluated using the Musculoskeletal Tumor Society (MSTS) guidelines after 6 months postoperatively, to analyze the relation between bone excision size and function recovery. RESULTS: The resection lengths measured intraoperatively ranged from 80 to 230 mm, and contained 3 cm of normal bone around the tumor. A total of 3 courses of preoperative chemotherapy were administered to all cases. At final follow-up, 1 case showed recurrence. Meanwhile, 8 patients (11.6%) died from lung metastasis. Post-operative infection occurred in 3 patients; 1 case was maintained with revision surgery. Two cases underwent amputation. The mean MSTS system score was 21.6. CONCLUSIONS: The multidisciplinary treatment result in an overall positive outcome, with improved function.

Influence of neoadjuvant chemotherapy on prognosis of patients with synovial sarcoma.

BACKGROUND: This study aimed to explore the clinical efficacy of neoadjuvant chemotherapy combined with surgery in primary synovial sarcoma of the limbs and trunk through retrospective analysis of patients with primary synovial sarcoma of the limbs and trunk treated by this treatment in our hospital. METHODS: A total of 89 patients diagnosed with synovial sarcoma were enrolled in this study between January 2005 and December 2011 in PLA General Hospital. Most of the patients received neoadjuvant chemotherapy combined with operative treatment (84.3%), 10.1% of them received adjuvant chemotherapy combined with operative treatment, and only 5.6% received merely operative treatment. The influence on the prognosis of patients with synovial sarcoma was analyzed by the statistics overall survival (OS), progression-free survival (PFS), local control (LC), and freedom from distant metastasis (FFDM). RESULTS: The median follow-up time was 68.6 months. The 5-year OS, 5-year PFS, 5-year LC, and 5-year FFDM of the patients were 80.2, 60.5, 78.8, and 80.8%, respectively. The OS of the patients with a tumor size >5 cm was lower (91.4 vs 73.1%, P < 0.05). Besides, the OS and FFDM of neoadjuvant chemotherapy were better than those of adjuvant chemotherapy (84.5 vs 55.6%, P = 0.015, and 83.8 vs 55.6%, P = 0.028, respectively). However, there was no significant difference in the LC and PFS. CONCLUSIONS: Neoadjuvant chemotherapy was beneficial for patients with synovial sarcoma, and it could improve survival time and control distant metastasis. Tumor size was an important factor influencing patients' prognosis.

Amputation Versus Limb-Salvage Surgery in Patients with Osteosarcoma: A Meta-analysis.

BACKGROUND: This meta-analysis compared survival and function in patients with limb osteosarcoma treated with limb-salvage surgery (LSS) versus amputation or rotationplasty. METHODS: Medline, Cochrane, EMBASE, and Google Scholar were searched until November 30, 2015 for studies reporting Musculoskeletal Tumor Society (MSTS) scores and survival rates in osteosarcoma patients. Differences between patients undergoing LSS versus ablative surgery were analyzed based on MSTS scores and postoperative survival rates. RESULTS: Of 1330 patients in the studies analyzed, 934 underwent LSS, and 662 were treated with amputation. A random-effects model was applied due to heterogeneity among studies (Q statistic = 1.829, I (2) = 0 %, p = 0.767). No difference was found in post-operative local recurrence rate between amputees and patients receiving LSS. The 5-year survival rate was significantly lower with amputation compared with LSS (OR 0.628; 95 % CI 0.431-0.913, p = 0.015). The 2-year survival rate was not different between amputation and LSS. In addition, amputees had lower MSTS scores than those undergoing LSS (difference in means = -4.46 %, 95 % CI 6.49-2.45 %, p < 0.001). CONCLUSIONS: LSS results in higher 5-year survival rates and better functional outcomes as indicated by MSTS scores in patients with limb osteosarcomas.

miR-382 inhibits osteosarcoma metastasis and relapse by targeting Y box-binding protein 1.

Lung metastasis and relapse in osteosarcoma (OS) patients indicate poor prognosis. Here, we identified significantly decreased expression of miR-382 in highly metastatic OS cell lines and relapsed OS samples compared to their parental cell lines and primary OS samples, respectively. In addition, our clinical data showed that the miR-382 expression level was inversely associated with relapse and positively associated with metastasis-free survival in OS patients. The overexpression of miR-382 suppressed epithelial-mesenchymal transition (EMT) and metastasis. This overexpression also decreased the cancer stem cell (CSC) population and function in OS cells. In contrast, inhibition of miR-382 stimulated EMT and metastasis and increased CSC population in OS cells. In addition, our in vivo experiments showed that the overexpression of miR-382 inhibited CSC-induced tumor formation, and the combination of miR-382 with doxorubicin prevented disease relapse in OS patients. Furthermore, we demonstrated that miR-382 exerted its tumor-suppressing potential by directly targeting Y box-binding protein 1 (YB-1) in OS. Taken together, our findings suggest that miR-382 functions as a tumor suppressor function and that the overexpression of miR-382 is a novel strategy to inhibit tumor metastasis and prevent CSC-induced relapse in OS.

Hinged External Fixation Combined with Open Debridement for Post-traumatic Elbow Stiffness: A Systematic Review and Meta-analysis.

Background: Open debridement remains the gold standard for the clinical treatment of post-traumatic elbow stiffness. However, postoperative complications, such as re-contraction and heterotopic ossification of the elbow joint, are highly prevalent. Hinged external fixation appears to offer the potential for greater improvement of joint function and reduction of complications. The purpose of this article is to provide the latest evidence on the effectiveness and safety of hinged external fixation combined with open debridement for the treatment of post-traumatic elbow stiffness. Methods: We searched for randomized controlled trials (RCTs) from the China National Knowledge Infrastructure, MEDLINE, PubMed, Web of Science, EMBASE, and Cochrane Library databases until December 31, 2022. STATA 15.1 software was used to analyze all the data for this article. The quality of the included articles was evaluated using the Cochrane Reviewer's Handbook 5.3. Results: Finally, we selected 8 high-quality RCTs for our meta-analysis, which included 555 patients. The meta-analysis demonstrated that hinged external fixation combined with open debridement for post-traumatic elbow stiffness (treatment group) showed a significant increase in elbow flexion and extension mobility (WMD = 5.16, 95% CI 4.39-5.49, Z = 13.02, P = 0.000), Mayo elbow function scores (WMD = 5.25, 95% CI 4.33-6.17, Z = 11.15, P = 0.000), and Mayo excellent rate (RR = 1.25, 95% CI 1.14-1.37, Z = 4.87, P = 0.000). Additionally, there was a significant decrease in the complication rate (RR = 1.11, 95% CI 1.02-1.20, Z = 2.54, P = 0.011) compared to open debridement alone (control group). Furthermore, the results of the publication bias test showed no significant bias. Conclusions: With the assistance of hinged external fixation, open debridement for post-traumatic elbow stiffness can lead to increased elbow mobility and a reduced complication rate. However, due to the small sample size, a multicenter randomized controlled trial with a larger sample size is still necessary to further confirm the effectiveness and safety of hinged external fixation combined with open debridement for post-traumatic elbow stiffness. Supplementary Information: The online version contains supplementary material available at 10.1007/s43465-023-01087-y.

Integrated transcriptomic analysis systematically reveals the heterogeneity and molecular characterization of cancer-associated fibroblasts in osteosarcoma.

BACKGROUND: Osteosarcoma (OS), with a peak incidence during the adolescent growth spurt, is correlated with poor prognosis for its high malignancy. The tumor microenvironment (TME) is highly complicated, with frequent interactions between tumor and stromal cells. The cancer-associated fibroblasts (CAFs) in the TME have been considered to actively involve in the progression, metastasis, and drug resistance of OS. This study aimed to characterize cellular heterogeneity and molecular characterization in CAFs subtypes and explore the potential targeting therapeutic strategies to improve the prognosis of OS patients. METHODS: The single-cell atlas of human OS tumor lesions were constructed from the GEO database. Then significant marker genes and potential biological functions for each CAFs subtype were identified and explored using the Seurat R package. Next, by performing the survival analyses and constructing the risk scores for CAFs subtypes, we aimed to identify and characterize the prognostic values of specific marker genes and different CAFs subtypes. Furthermore, we explored the therapeutic targets and innovative drugs targeting different CAFs subtypes based on the GDSC database. Finally, prognoses related CAFs subtypes were further validated through immunohistochemistry (IHC) on clinical OS specimens. RESULTS: Overall, nine main cell clusters and five subtypes of CAFs were identified. The differentially expressed marker genes for each CAFs clusters were then identified. Moreover, through Gene Ontology (GO) enrichment analysis, we defined the CAFs_2 (upregulated CXCL14 and C3), which was closely related to leukocyte migration and chemotaxis, as inflammatory CAFs (iCAFs). Likewise, we defined the CAFs_4 (upregulated CD74, HLA-DRA and HLA-DRB1), which was closely related to antigen process and presentation, as antigen-presenting CAFs (apCAFs). Furthermore, Kaplan-Meier analyses showed that CAFs_2 and CAFs_4 were correlated with poor clinical prognosis of OS patients. Meanwhile, therapeutic drugs targeting CAFs_2 and CAFs_4, such as 17-AAG/Docetaxel/Bleomycin and PHA-793887/NG-25/KIN001-102, were also explored, respectively. Finally, IHC assay confirmed the abundant CAFs_2 and CAFs_4 subtypes infiltration in the OS microenvironment compared with adjacent tissues. CONCLUSION: Our study revealed the diversity, complexity, and heterogeneity of CAFs in OS, and complemented the single-cell atlas in OS TME.

Neoadjuvant Chemotherapy and Expandable Prosthesis Reconstruction to Treat Osteosarcoma around the Knee in Children.

OBJECTIVE: Survival and reconstruction in osteosarcoma is quite challenging. The study aimed to investigate the prognosis in patients treated with neoadjuvant chemotherapy and determine the clinical outcomes of expandable endoprosthesis reconstruction in children. METHODS: From January 2009 to December 2014, we retrospectively analyzed 29 skeletally immature children (mean age, 10.5 years; range, 6-15 years) with osteosarcoma around the knee. Of the 29 patients who underwent neoadjuvant chemotherapy and limb salvage surgery, an expandable prosthesis was implanted for reconstruction. No patients were missed during follow-up. The evaluation index involved follow-up time, complication, functional results, and lengthening procedures. The survivorship and recurrence were assessed by GraphPad Software, and the function was evaluated by the Musculoskeletal Tumor Society (MSTS) scoring system. RESULTS: A mean follow-up time was 8.9 years (range, 6-12 years), and the overall 5-year survival was 89.1% based on Kaplan-Meier analysis. Three patients suffered a relapse and one underwent amputation. Lung metastasis developed in one patient. At 6 months after the operation, patients had a mean MSTS score of 27 points (range, 24-29). Two patients underwent revision surgery, one for implant infection and one for aseptic loosening. Prognosis is correlated with alkaline phosphatase change after treatment. CONCLUSIONS: Chemotherapy scheme and limb salvage can achieve high survival rates. This expandable prosthesis was associated with good function and low complication rates. The character of expandability could be a method to overcome discrepancies in the growth period.

[Application of TightRope system combined with Locking-Loop biplane anatomical reconstruction technique for acute acromioclavicular joint dislocation].

Objective: To investigate the effectiveness of TightRope system combined with Locking-Loop biplane anatomical reconstruction technique in the treatment of acute acromioclavicular joint dislocation. Methods: A clinical data of 28 patients with acute acromioclavicular joint dislocation who met the selection criteria and admitted between June 2018 and December 2021 was retrospectively analyzed. There were 18 males and 10 females, with an average age of 47.7 years (range, 22-72 years). The causes of injury included falling (13 cases) and traffic accidents (15 cases). The acromioclavicular joint dislocation was rated as Rockwood type Ⅲ in 7 cases, type Ⅳ in 16 cases, and type Ⅴ in 5 cases. The time from injury to operation was 4-13 days, with an average of 9.5 days. The acromioclavicular joint dislocation was reconstructed with TightRope system and high-strength wire by Locking-Loop methods during operation. The operation time and complications were recorded. Visual analogue scale (VAS) score, Constant-Murley score, and active range of motion of shoulder (forward flexion and upward lift, abduction and upward lift, and external rotation) were recorded before operation and at 12 months after operation to evaluate the functional recovery of shoulder. The loss of acromioclavicular joint reduction was assessed by comparing the coracoclavicular distance (CCD) based on the anteroposterior X-ray films at 3 days and 12 months after operation. Results: The operation time was 58-100 minutes (median, 85 minutes). All incisions healed by first intention. All patients were followed up 12 months. During follow-up, 2 patients developed shoulder adhesion, which recovered after rehabilitation exercise. At 12 months after operation, the VAS score was significantly lower, the Constant-Murley score was significantly higher, and the range of motion of the shoulder joint (forward flexion and upward lift, abduction and upward lift, and external rotation) significantly increased when compared with preoperative ones ( P<0.05). X-ray films showed that the CCD was 8.4 (7.3, 9.4) and 9.2 (8.1, 10.1) mm at 3 days and 12 months after operation, respectively, with a significant difference ( Z=-4.665, P<0.001). During follow-up, there was no complication such as infection, titanium plate entrapment, fracture, internal fixation failure, or redislocation. Conclusion: The treatment of acute acromioclavicular joint dislocation with TightRope system combined with Locking-Loop biplane anatomical reconstruction has the advantages of small incision, joint reduction under direct vision, high fixation strength, and low incidence of postoperative complications, which can effectively relieve the pain of patients' shoulder joint and facilitate the recovery of shoulder joint function.

[Effectiveness analysis of resection and reconstruction of primary bone tumor in pelvic zone â ¡].

Objective: To investigate the effectiveness of complete resection of bone tumor in pelvic zone Ⅱ and reconstruction with allogeneic pelvis, modular prosthesis, and three-dimensional (3D) printing prosthesis. Methods: The clinical data of 13 patients with primary bone tumor in pelvic zone Ⅱ who underwent tumor resection and acetabular reconstruction between March 2011 and March 2022 were retrospectively analyzed. There were 4 males and 9 females with an average age of 39.0 years ranging from 16 to 59 years. There were 4 cases of giant cell tumor, 5 cases of chondrosarcoma, 2 cases of osteosarcoma, and 2 cases of Ewing sarcoma. The Enneking classification of pelvic tumors showed that 4 cases involved zone Ⅱ, 4 cases involved zone Ⅰ and zone Ⅱ, and 5 cases involved zone Ⅱ and zone Ⅲ. The disease duration ranged from 1 to 24 months, with an average of 9.5 months. The patients were followed up to observe the recurrence and metastasis of the tumor, and the imaging examination was performed to observe the status of implant in place, fracture, bone resorption, bone nonunion, and so on. The improvement of hip pain was evaluated by visual analogue scale (VAS) score before operation and at 1 week after operation, and the recovery of hip function was evaluated according to the Musculoskeletal Tumor Society (MSTS) scoring system after operation. Results: The operation time was 4-7 hours, with an average of 4.6 hours; the intraoperative blood loss ranged from 800 to 1 600 mL, with an average of 1 200.0 mL. There was no reoperation or death after operation. All patients were followed up 9-60 months (mean, 33.5 months). No tumor metastasis was found in 4 patients receiving chemotherapy during follow-up. Postoperative wound infection occurred in 1 case, and prosthesis dislocation occurred in 1 case at 1 month after prosthesis replacement. One case of giant cell tumor recurred at 12 months after operation, and the puncture biopsy showed malignant transformation of giant cell tumor, and hemipelvic amputation was performed. The postoperative hip pain significantly relieved, and the VAS score was 6.1±0.9 at 1 week after operation, which was significantly different from the preoperative score (8.2±1.3) ( t=9.699, P<0.001). At 12 months after operation, the MSTS score was 23.0±2.1, including 22.8±2.1 for patients with allogenic pelvis reconstruction and 23.3±2.3 for patients with prosthsis reconstruction. There was no significant difference in the MSTS score between the two reconstruction methods ( t=0.450, P=0.516). At last follow-up, 5 patients could walk with cane assistance and 7 patients could walk without cane assistance. Conclusion: The resection and reconstruction of primary bone tumor in pelvic zone Ⅱ can obtain satisfactory hip function, and the interface of allogeneic pelvis and 3D printing prosthesis have better bone ingrowth, which is more in line with the requirements of biomechanics and biological reconstruction. However, pelvis reconstruction is difficult, the patient's condition should be evaluated comprehensively before operation, and the long-term effectiveness needs further follow-up.

Sulfatinib, a novel multi-targeted tyrosine kinase inhibitor of FGFR1, CSF1R, and VEGFR1-3, suppresses osteosarcoma proliferation and invasion via dual role in tumor cells and tumor microenvironment.

Introduction: Tumor progression is driven by intrinsic malignant behaviors caused by gene mutation or epigenetic modulation, as well as crosstalk with the components in the tumor microenvironment (TME). Considering the current understanding of the tumor microenvironment, targeting the immunomodulatory stromal cells such as cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) could provide a potential therapeutic strategy. Here, we investigated the effect of sulfatinib, a multi-targeted tyrosine kinase inhibitor (TKI) of FGFR1, CSF1R, and VEGFR1-3, on the treatment of osteosarcoma (OS). Methods: In vitro, the antitumor effect was tested by clony formation assay and apoptosis assay.The inhibition of tumor migration and invasion was detected by Transwell assay, and the de-polarization of macrophage was detected by flow cytometry.In vivo, subcutaneous and orthotopic tumor models were established to verify antitumor effect, and the underlying mechanism was verified by immunohistochemistry(IHC), immunofluorescence(IF) and flow cytometry. Results: Sulfatinib suppressed OS cell migration and invasion by inhibiting epithelial-mesenchymal transition (EMT) by blocking the secretion of basic fibroblast growth factor (bFGF) in an autocrine manner. In addition, it regulated immune TME via inhibition of the migration of skeletal stem cells (SSCs) to the TME and the differentiation from SSCs to CAFs. Moreover, sulfatinib can suppress OS by modulation of the TME by inhibiting M2 polarization of macrophages. Systemic treatment of sulfatinib can reduce immunosuppression cells M2-TAMs, Tregs, and myeloid-derived suppressor cells (MDSCs) and increase cytotoxic T-cell infiltration in tumors, the lungs, and the spleens. Discussion: Our preclinical experiments have shown that sulfatinib can inhibit the proliferation, migration, and invasion of OS by playing a dual role on tumor cells and the tumor microenvironment simultaneously and systematically reverse immunosuppression to immune activation status, which could be translated into clinical trials.

Combination of IDO inhibitors and platinum(IV) prodrugs reverses low immune responses to enhance cancer chemotherapy and immunotherapy for osteosarcoma.

In recent years, immune checkpoint blockades (ICBs) have made great progress in the treatment of cancer. However, most ICBs have not yet been observed to be satisfactory in the treatment of osteosarcoma. Herein, we designed composite nanoparticles (NP-Pt-IDOi) from a reactive oxygen species (ROS) sensitive amphiphilic polymer (PHPM) with thiol-ketal bonds in the main chain to encapsulate a Pt(IV) prodrug (Pt(IV)-C12) and an indoleamine-(2/3)-dioxygenase (IDO) inhibitor (IDOi, NLG919). Once NP-Pt-IDOi enter the cancer cells, the polymeric nanoparticles could dissociate due to the intracellular ROS, and release Pt(IV)-C12 and NLG919. Pt(IV)-C12 induces DNA damage and activates the cGAS-STING pathway, increasing infiltration of CD8+ T cells in the tumor microenvironment. In addition, NLG919 inhibits tryptophan metabolism and enhances CD8+ T cell activity, ultimately activating anti-tumor immunity and enhancing the anti-tumor effects of platinum-based drugs. NP-Pt-IDOi were shown to have superior anti-cancer activity in vitro and in vivo in mouse models of osteosarcoma, providing a new clinical paradigm for combining chemotherapy with immunotherapy for osteosarcoma.

The c-Abl-MST1 signaling pathway mediates oxidative stress-induced neuronal cell death.

Oxidative stress influences cell survival and homeostasis, but the mechanisms underlying the biological effects of oxidative stress remain to be elucidated. The protein kinase MST1 (mammalian Ste20-like kinase 1) plays a major role in oxidative stress-induced cell death in primary mammalian neurons. However, the mechanisms that regulate MST1 in oxidative stress responses remain largely unknown. In the present study, we demonstrate that the protein kinase c-Abl phosphorylates MST1 at Y433, which triggers the stabilization and activation of MST1. Inhibition of c-Abl promotes the degradation of MST1 through C terminus of Hsc70-interacting protein (CHIP)-mediated ubiquitination, and thereby attenuates cell death. Oxidative stress induces the c-Abl-dependent tyrosine phosphorylation of MST1 and increases the interaction between MST1 and FOXO3 (Forkhead box O3), thereby activating the MST1-FOXO signaling pathway, leading to cell death in both primary culture neurons and rat hippocampal neurons. The identification of the c-Abl tyrosine kinase as a novel upstream activator of MST1 suggests that the c-Abl-MST1 signaling cascade plays an important role in cellular responses to oxidative stress.

MST1 promotes apoptosis through regulating Sirt1-dependent p53 deacetylation.

Mammalian Sterile 20-like kinase 1 (MST1) protein kinase plays an important role in the apoptosis induced by a variety of stresses. The MST1 is a serine/threonine kinase that is activated upon apoptotic stimulation, which in turn activates its downstream targets, JNK/p38, histone H2B and FOXO. It has been reported that overexpression of MST1 initiates apoptosis by activating p53. However, the molecular mechanisms underlying MST1-p53 signaling during apoptosis are unclear. Here, we report that MST1 promotes genotoxic agent-induced apoptosis in a p53-dependent manner. We found that MST1 increases p53 acetylation and transactivation by inhibiting the deacetylation of Sirtuin 1 (Sirt1) and its interaction with p53 and that Sirt1 can be phosphorylated by MST1 leading to the inhibition of Sirt1 activity. Collectively, these findings define a novel regulatory mechanism involving the phosphorylation of Sirt1 by MST1 kinase which leads to p53 activation, with implications for our understanding of signaling mechanisms during DNA damage-induced apoptosis.

C-Myc overexpression promotes osteosarcoma cell invasion via activation of MEK-ERK pathway.

Osteosarcoma is a highly metastatic malignancy often with poor prognosis. c-Myc amplification is implicated in osteosarcoma pathogenesis. However, the role of c-myc overexpression in osteosarcoma cell invasion remains unexplored. This study showed that c-myc overexpression enhanced MG-63 and SAOS-2 osteosarcoma cell invasion. Treatment of MEK inhibitor PD98059 or PI3K inhibitor LY294002 decreased cell invasion along with downregulation of MMP-2 and MMP-9 expression. c-Myc overexpression stimulated MEK-ERK pathway whereas inhibited the activity of PI3K-AKT pathway. Specifically, inhibition of MEK-ERK pathway by PD98509 blocked the enhancement effect on cell invasion as well as MMP-2 and MMP-9 expression. The present study demonstrates that c-myc overexpression promotes osteosarcoma cell invasion, probably via activation of MEK-ERK pathway.

Screening and Analysis of Biomarkers in the miRNA-mRNA Regulatory Network of Osteosarcoma.

Osteosarcoma is a malignant disease, and few effective strategies can completely overcome the prognosis of these patients. This study attempted to reveal the key factors and related molecular mechanisms of osteosarcoma via excavating public microarray datasets. The data were obtained from the Gene Expression Omnibus (GEO) database; the differentially expressed miRNAs and differentially expressed genes were obtained in GSE69470 and GSE12685l, respectively; the target of miRNAs were predicted with the miRDIP database; the functions of the factors were analyzed and visualized by the David database and R language, respectively. Moreover, the protein-protein interaction network and miRNA-mRNA network were performed with the STRING database and Cytoscape software to identify the hub nodes in GSE69470 and GSE12685. The results showed that 834 DEGs were found in GSE12685 and 37 miRNAs were found in GSE69470. Moreover, the target of 37 miRNAs were enriched in PI3K/AKT, P53, Wnt/ß-catenin, and TGF-ß pathways and related with skeletal system development and cell growth. Besides, the miRNAs including miR-22-3p, miR-154-5p, miR-34a-5p, miR-485-3p, miR-93-5p, and miR-9-5p and the genes including LEF1, RUNX2, CSF1R, CDKN1A, and FBN1 were identified as the hub nodes via network analysis. In conclusion, this study suggested that the miRNAs including miR-22-3p, miR-154-5p, miR-34a-5p, miR-485-3p, miR-93-5p, and miR-9-5p and the genes including LEF1, RUNX2, CSF1R, CDKN1A, and FBN1 act as key factors in the progression of osteosarcoma.

[Effectiveness of arthroscopic long head of biceps tendon transposition combined with Swivelock anchor double fixation for massive and irreparable rotator cuff tears].

Objective: To investigate the effectiveness of arthroscopic long head of biceps tendon (LHBT) transposition combined with Swivelock anchor double fixation in treatment of massive and irreparable rotator cuff tears. Methods: Between June 2019 and November 2021, 25 patients with massive and irreparable rotator cuff tears were treated by arthroscopic LHBT transposition combined with Swivelock anchor double fixation. There were 12 males and 13 females. The age ranged from 47 to 74 years (mean, 62.4 years). The disease duration ranged from 1 to 62 months (median, 7 months). The rotator cuff tears were classified as Hamada grade 2 in 25 cases and Goutallier grade 1 in 2 cases, grade 2 in 22 cases, and grade 3 in 1 case. Pre- and post-operative shoulder range of motion (ROM), visual analogue scale (VAS) score, University of California Los Angeles (UCLA) score, and Constant-Murley score were recorded. Postoperative complications were observed. The reconstructed tissue integrity was confirmed by MRI. Results: All operations were successfully completed. The operation time was 120-330 minutes (mean, 189.6 minutes). All incisions healed by first intention. All patients were followed up 10-36 months (mean, 22.0 months). At last follow-up, the ROM in forward flexion, abduction, and external rotation, VAS score, UCLA score, and Constant-Murley score were superior to those before operation, and the differences were significant ( P<0.05). According to UCLA scoring standard, shoulder joint function was rated as excellent in 5 cases, good in 18 cases, and poor in 2 cases, with an excellent and good rate of 92.0%. No other complications occurred except shoulder joint adhesion in 2 cases. At last follow-up, MRI examination showed no retear of rotator cuff, and LHBT was intact. Conclusion: For massive and irreparable rotator cuff tears, arthroscopic LHBT transposition combined with Swivelock anchor double fixation can increase the force of pressing the humeral head, effectively relieve the pain, improve the ROM of joints, maximize the recovery of shoulder function, and do not increase the number of anchor nails.

[Effectiveness analysis of computer-aided technology in the treatment of primary elbow osteoarthritis combined with stiffness under arthroscopy].

Objective: To explore the effectiveness of computer-aided technology in the treatment of primary elbow osteoarthritis combined with stiffness under arthroscopy. Methods: The clinical data of 32 patients with primary elbow osteoarthritis combined with stiffness between June 2018 and December 2020 were retrospectively analyzed. There were 22 males and 10 females with an average age of 53.4 years (range, 31-71 years). X-ray film and three-dimensional CT examinations showed osteophytes of varying degrees in the elbow joint. Loose bodies existed in 16 cases, and there were 7 cases combined with ulnar nerve entrapment syndrome. The median symptom duration was 2.5 years (range, 3 months to 22.5 years). The location of bone impingement from 0° extension to 140° flexion of the elbow joint was simulated by computer-aided technology before operation and a three-dimensional printed model was used to visualize the amount and scope of impinging osteophytes removal from the anterior and posterior elbow joint to accurately guide the operation. Meanwhile, the effect of elbow joint release and impinging osteophytes removal was examined visually under arthroscopy. The visual analogue scale (VAS) score, Mayo elbow performance score (MEPS), and elbow range of motion (extension, flexion, extension and flexion) were compared between before and after operation to evaluate elbow function. Results: The mean operation time was 108 minutes (range, 50-160 minutes). All 32 patients were followed up 9-18 months with an average of 12.5 months. There was no other complication such as infection, nervous system injury, joint cavity effusion, and heterotopic ossification, except 2 cases with postoperative joint contracture at 3 weeks after operation due to the failure to persist in regular functional exercises. Loose bodies of elbow and impinging osteophytes were removed completely for all patients, and functional recovery was satisfactory. At last follow-up, VAS score, MEPS score, extension, flexion, flexion and extension range of motion significantly improved when compared with preoperative ones ( P<0.05). Conclusion: Arthroscopic treatment of primary elbow osteoarthritis combined with stiffness using computer-aided technology can significantly reduce pain, achieve satisfactory functional recovery and reliable effectiveness.