Osteosarcoma in Adolescents and Young Adults

Recent advances in nanoagents delivery system-based phototherapy for osteosarcoma treatment

Osteosarcoma (OS) is a prevalent and highly malignant bone tumor, characterized by its aggressive nature, invasiveness, and rapid progression, contributing to a high mortality rate, particularly among adolescents. Traditional treatment modalities, including surgical resection, radiotherapy, and chemotherapy, face significant challenges, especially in addressing chemotherapy resistance and managing postoperative recurrence and metastasis. Phototherapy (PT), encompassing photodynamic therapy (PDT) and photothermal therapy (PTT), offers unique advantages such as low toxicity, minimal drug resistance, selective destruction, and temporal control, making it a promising approach for the clinical treatment of various malignant tumors. Constructing multifunctional delivery systems presents an opportunity to effectively combine tumor PDT, PTT, and chemotherapy, creating a synergistic anti-tumor effect. This review aims to consolidate the progress in the application of novel delivery system-mediated phototherapy in osteosarcoma. By summarizing advancements in this field, the objective is to propose a rational combination therapy involving targeted delivery systems and phototherapy for tumors, thereby expanding treatment options and enhancing the prognosis for osteosarcoma patients. In conclusion, the integration of innovative delivery systems with phototherapy represents a promising avenue in osteosarcoma treatment, offering a comprehensive approach to overcome challenges associated with conventional treatments and improve patient outcomes.

Reversine inhibits proliferation and induces apoptosis of human osteosarcoma cells through targeting MEK1

Reversine, or 2-(4-morpholinoanilino)-6-cyclohexylaminopurine, is a 2,6-disubstituted purine derivative. This small molecule shows anti-tumor potential by playing a central role in the inhibition of several kinases related to cell cycle regulation and cytokinesis. In this study, systematic review demonstrated the feasibility and pharmacological mechanism of anti-tumor effect of reversine. Firstly, we grafted MNNG/HOS, U-2 OS, MG-63 osteosarcoma cell aggregates onto chicken embryonic chorioallantoic membrane (CAM) to examine the tumor volume of these grafts after reversine treatment. Following culture, reversine inhibited the growth of osteosarcoma cell aggregates on CAM significantly. In vitro experiment, reversine suppressed osteosarcoma cell viability, colony formation, proliferation, and induced apoptosis and cell cycle arrest at G0-G1 phase. Scratch wound assay demonstrated that reversine restrained cell migration. Reversine increased the protein expression of E-cadherin. The mRNA expression of Rac1, RhoA, CDC42, PTK2, PXN, N-cadherin, Vimentin in MNNG/HOS, U-2 OS and MG-63 cells were suppressed and PTEN increased after reversine treatment. Network pharmacology prediction, molecular docking and systematic review revealed MEK1 can be used as an effective target for reversine to inhibit osteosarcoma. Western blot results show the regulation of MEK1 and ERK1/2 by reversine was not consistent in different osteosarcoma cell lines, but we found that reversine significantly inhibited the protein expression of MEK1 in MNNG/HOS, U-2 OS and MG-63. All these suggested that reversine can exert its anti-tumor effect by targeting the expression of MEK1.

Single-cell transcriptional profiling in osteosarcoma and the effect of neoadjuvant chemotherapy on the tumor microenvironment

Osteosarcoma (OS), a malignant tumor, originates from the bone marrow. Currently, treatment for OS remains limited, making it urgent to understand the immune response in the tumor microenvironment of patients with OS. A comprehensive bioinformatics analysis was performed, including cell clustering subgroups, differential expression genes screening, proposed temporal order, and genomic variant analysis on single-cell RNA-sequencing data, from ten pre-chemotherapy patients and eleven post-chemotherapy patients. Subsequently, we analyzed the differentiation trajectories of osteoblasts, osteoclasts, fibroblasts, myeloid cells, and tumor-infiltrating lymphocytes (TILs) in detail to compare the changes in cell proportions and differential genes pre- and post-chemotherapy. The nine cell types were identified, including fibroblasts, myeloid cells, osteoblasts, TILs, osteoclasts, proliferative osteoblasts, pericytes, endothelial cells, and B cells. Post-chemotherapy treatment, the proportions of myeloid cells and TILs in OS were declined, while the number of osteoblasts was elevated. Besides, a decrease was observed in CD74, FTL, FTH1, MT1X and MT2A, and an increase in PTN, COL3A1, COL1A1, IGFBP7 and FN1. Meanwhile, EMT, DNA repair, G2M checkpoint, and E2F targets were highly enriched post-chemotherapy. Furthermore, there was a down-regulation in the proportions of CD14 monocytes, Tregs, NK cells and CD1C-/CD141-DCs, while an up-regulation was observed in the proportions of SELENOP macrophages, IL7R macrophages, COL1A1 macrophages, CD1C DCs, CD4+ T cells and CD8+ T cells. Overall, these findings revealed changes in the tumor microenvironment of OS post-chemotherapy treatment, providing a new direction for investigating OS treatment.

Prognositic value of anoikis and tumor immune microenvironment-related gene in the treatment of osteosarcoma

OBJECTIVES

Osteosarcoma is a highly aggressive primary malignant bone tumor commonly seen in children and adolescents, with a poor prognosis. Anchorage-dependent cell death (anoikis) has been proven to be indispensable in tumor metastasis, regulating the migration and adhesion of tumor cells at the primary site. However, as a type of programmed cell death, anoikis is rarely studied in osteosarcoma, especially in the tumor immune microenvironment. This study aims to clarify prognostic value of anoikis and tumor immune microenvironment-related gene in the treatment of osteosarcoma.

METHODS

Anoikis-related genes (ANRGs) were obtained from GeneCards. Clinical information and ANRGs expression profiles of osteosarcoma patients were sourced from the therapeutically applicable research to generate effective therapies and Gene Expression Omnibus (GEO) databases. ANRGs highly associated with tumor immune microenvironment were identified by the estimate package and the weighted gene coexpression network analysis (WGCNA) algorithm. Machine learning algorithms were performed to construct long-term survival predictive strategy, each sample was divided into high-risk and low-risk subgroups, which was further verified in the GEO cohort. Finally, based on single-cell RNA-seq from the GEO database, analysis was done on the function of signature genes in the osteosarcoma tumor microenvironment.

RESULTS

A total of 51 hub ANRGs closely associated with the tumor microenvironment were identified, from which 3 genes (MERTK, BNIP3, S100A8) were selected to construct the prognostic model. Significant differences in immune cell activation and immune-related signaling pathways were observed between the high-risk and low-risk groups based on tumor microenvironment analysis (all P<0.05). Additionally, characteristic genes within the osteosarcoma microenvironment were identified in regulation of intercellular crosstalk through the GAS6-MERTK signaling pathway.

CONCLUSIONS

The prognostic model based on ANRGs and tumor microenvironment demonstrate good predictive power and provide more personalized treatment options for patients with osteosarcoma.

A Specific, Measurable, Achievable, Relevant, Timed (SMART) Nursing Project Reduces Anxiety, Depression, and Post-Traumatic Stress Disorder in Parents of Childhood or Adolescent Osteosarcoma Patients

Specific, measurable, achievable, relevant, timed (SMART) principle improves the nursing utility by setting individual goals for participants and helping them to achieve these goals. Our study intended to investigate the impact of a SMART nursing project on reducing mental stress and post-traumatic stress disorder (PTSD) in parents of childhood or adolescent osteosarcoma patients. In this randomized, controlled study, 66 childhood or adolescent osteosarcoma patients and 126 corresponding parents were enrolled and divided into SMART or normal care (NC) groups at a 1:1 ratio. All parents received a 3-month corresponding intervention and a 6-month interview. Our study revealed that the self-rating anxiety scale score at the 3rd month (M3) (P < 0.05) and the 6th month (M6) (P < 0.01), and anxiety rate at M3 (P < 0.05) and M6 (P < 0.05) were lower in parents in SMART group vs. NC group. The self-rating depression scale score at M3 and M6, and depression rate at M3 and M6 were lower in parents in SMART group vs. NC group (all P < 0.05). Impact of events scale-revised score at the 1st month (M1) (P < 0.05), M3 (P < 0.05), and M6 (P < 0.01) were lower in parents in SMART group vs. NC group. By subgroup analyses, the SMART nursing project showed better impacts on decreasing anxiety, depression, and PTSD in parents with an undergraduate education or above than in those with a high school education or less. Conclusively, SMART nursing project reduces anxiety, depression, and PTSD in parents of childhood or adolescent osteosarcoma patients, which is more effective in those with higher education.

ZNF692 promotes osteosarcoma cell proliferation, migration, and invasion through TNK2-mediated activation of the MEK/ERK pathway

BACKGROUND

Osteosarcoma is a diverse and aggressive bone tumor. Driver genes regulating osteosarcoma initiation and progression remains incompletely defined. Zinc finger protein 692 (ZNF692), a kind of Krüppel C2H2 zinc finger transcription factor, exhibited abnormal expression in different types of malignancies and showed a correlation with the clinical prognosis of patients as well as the aggressive characteristics of cancer cells. Nevertheless, its specific role in osteosarcoma is still not well understood.

METHODS

We investigated the dysregulation and clinical significance of ZNF692 in osteosarcoma through bioinformatic method and experimental validation. A range of in vitro assays, including CCK-8, colony formation, EdU incorporation, wound healing, and transwell invasion tests, were conducted to assess the impact of ZNF692 on cell proliferation, migration, and invasion in osteosarcoma. A xenograft mouse model was established to evaluate the effect of ZNF692 on tumor growth in vivo. Western blot assay was used to measure the protein levels of MEK1/2, P-MEK1/2, ERK1/2, and P-ERK1/2 in cells that had been genetically modified to either reduce or increase the expression of ZNF692. The relationship between ZNF692 and tyrosine kinase non-receptor 2 (TNK2) were validated by qRT-PCR, chromatin immunoprecipitation and luciferase reporter assays.

RESULTS

Expression of ZNF692 was increased in both human osteosarcoma tissues and cell lines. Furthermore, the expression of ZNF692 served as an independent predictive biomarker in osteosarcoma. The results of the survival analysis indicated that increased expression of ZNF692 was associated with worse outcome. Downregulation of ZNF692 inhibits the proliferation, migration, and invasion of osteosarcoma cells, whereas upregulation of ZNF692 has the opposite impact. Western blot assay indicates that reducing ZNF692 decreases phosphorylation of MEK1/2 and ERK1/2, whereas increasing ZNF692 expression enhances their phosphorylation. U0126, a potent inhibitor specifically targeting the MEK/ERK signaling pathway, partially counteracts the impact of ZNF692 overexpression on the proliferation, migration, and invasion of osteosarcoma cells. In addition, ZNF692 specifically interacts with the promoter region of TNK2 and stimulates the transcription of TNK2 in osteosarcoma cells. Forcing the expression of TNK2 weakens the inhibitory impact of ZNF692 knockdown on P-MEK1/2 and P-ERK1/2. Similarly, partly inhibiting TNK2 counteracts the enhancing impact of ZNF692 overexpression on the phosphorylation of MEK1/2 and ERK1/2. Functional tests demonstrate that the suppressive effects of ZNF692 knockdown on cell proliferation, migration, and invasion are greatly reduced when TNK2 is overexpressed. In contrast, the reduction of TNK2 hinders the ability of ZNF692 overexpression to enhance cell proliferation, migration, and invasion.

CONCLUSION

ZNF692 promotes the proliferation, migration, and invasion of osteosarcoma cells via the TNK2-dependent stimulation of the MEK/ERK signaling pathway. The ZNF692-TNK2 axis might potentially function as a possible predictive biomarker and a promising target for novel therapeutics in osteosarcoma.

Identifying immune-related prognostic biomarkers in osteosarcoma: Development and validation of the tumor immune microenvironment risk model based on analysis of TCGA

OBJECTIVE

Osteosarcoma is a rare and aggressive malignancy with limited effective therapeutic options. This study aimed to identify immune-related prognostic biomarkers and develop a prognostic model for osteosarcoma.

METHODS

We performed integrated analysis of transcriptomic data and immune cell infiltration profiles of 84 osteosarcoma samples from the Cancer Genome Atlas (TCGA) database. Time-dependent receiver operating characteristic (ROC) curve analysis was used to assess the prognostic value of the TIMErisk model. We also performed functional annotation and pathway enrichment analyses to explore the potential mechanisms underlying the TIMErisk model.

RESULTS

We identified a seven-gene TIMErisk model (C2, APBB1IP, BST2, TRPV2, CCL5, GBP1, and F13A1) that was independently associated with overall survival of osteosarcoma patients. The TIMErisk model showed significant associations with immune cell infiltration and immunosuppressive gene expression. In addition, the TIMErisk model was associated with drug sensitivity, and we found that several immune checkpoint genes were significantly differentially expressed between high- and low-TIMErisk groups. Functional annotation and pathway enrichment analyses revealed that the TIMErisk model was associated with multiple immune-related pathways, including antigen processing and presentation, cytokine-cytokine receptor interaction, and T cell receptor signaling pathway.

CONCLUSION

Our study identified a novel TIME-based prognostic model for osteosarcoma that incorporates immune-related genes and can be used to predict patient prognosis and response to immunotherapy. Our findings highlight the importance of the TIME microenvironment in osteosarcoma progression and suggest that immune-related biomarkers may have clinical significance in the management of osteosarcoma.

MiR362-3p Alleviates Osteosarcoma by Regulating the IL6ST/JAK2/STAT3 Pathway in Vivo and in Vitro

Objectives: To investigate the effects and the related signaling pathway of miR-362-3p on OS. Methods: The bioinformatics analysis approaches were employed to investigate the target pathway of miR-362-3p. After the 143B and U2OS cells and nu/nu male mice were randomly divided into blank control (BC) group, normal control (NC) group, and overexpression group (OG), the CCK-8, EdU staining, wound healing assay, Transwell assay, and TUNEL staining were adopted to respectively determine the effects of overexpressed miR-362-3p on the cell viability, proliferation, migration, invasion, and apoptosis of 143B and U2OS cells in vitro, tumor area assay and hematoxylin and eosin staining were employed to respectively determine the effects of overexpressed miR-362-3p on the growth and pathological injury of OS tissue in vivo. The qRT-PCR, Western blot, and immunohistochemical staining were applied to respectively investigate the effects of overexpressed miR-362-3p on the IL6ST/JAK2/STAT3 pathway in OS in vivo and in vitro. Results: The bioinformatics analysis approaches combined qRT-PCR indicated that the IL6ST/JAK2/STAT3 is one of the target pathways of miR-362-3p. Compared with NC, the cell viability, proliferation, migration, and invasion of 143B and U2OS cells were dramatically (P < 0.01) inhibited but the apoptosis was prominently (P <0 .0001) promoted in OG. Compared with NC, the growth of OS tissue was significantly (P < 0.05) suppressed and the pathological injury of OS tissue was substantially aggravated in OG. The gene expression levels of IL6ST, JAK2, and STAT3 and the protein expression levels of IL6ST, JAK2, p-JAK2, STAT3, and p-STAT3 in 143B and U2OS cells were memorably (P < 0.0001) lower in OG than those in NC. In addition, the positively stained areas of proteins of IL6ST, JAK2, p-JAK2, STAT3, and p-STAT3 of OS tissue in OG were markedly (P < 0.01) reduced compared with those in NC. Conclusion: The overexpression of miR362-3p alleviates OS by inhibiting the IL6ST/JAK2/STAT3 pathway in vivo and in vitro.

Nano-Based Drug Delivery Systems: Potential Developments in the Therapy of Metastatic Osteosarcoma-A Narrative Review

Osteosarcoma, a predominant malignant bone tumor, poses significant challenges due to its high metastatic and recurrent nature. Although various therapeutic strategies are currently in use, they often inadequately target osteosarcoma metastasis. This review focuses on the potential of nanoscale drug delivery systems to bridge this clinical gap. It begins with an overview of the molecular mechanisms underlying metastatic osteosarcoma, highlighting the limitations of existing treatments. The review then transitions to an in-depth examination of nanoscale drug delivery technologies, emphasizing their potential to enhance drug bioavailability and reduce systemic toxicity. Central to this review is a discussion of recent advancements in utilizing nanotechnology for the potential intervention of metastatic osteosarcoma, with a critical analysis of several preclinical studies. This review aims to provide insights into the potential applications of nanotechnology in metastatic osteosarcoma therapy, setting the stage for future clinical breakthroughs and innovative cancer treatments.

Zyxin Inhibits the Proliferation, Migration, and Invasion of Osteosarcoma via Rap1-Mediated Inhibition of the MEK/ERK Signaling Pathway

Zyxin (ZYX) is an actin-interacting protein with unknown biological functions in patients with osteosarcoma. This research sought to understand how ZYX affects the biological behavior of osteosarcoma cells and to identify the associated mechanism. Firstly, ZYX expression was decreased in osteosarcoma, and its higher expression indicated better outcomes in patients with osteosarcoma. ZYX overexpression significantly inhibited the proliferation, migration, and invasion of osteosarcoma cells, whereas ZYX silencing resulted in the opposite trend. Subsequently, we found that the Rap1 signaling pathway was significantly correlated with ZYX expression as reported in The Cancer Genome Atlas's database using bioinformatic analysis. Moreover, we found that ZYX overexpression regulated the Rap1/MEK/ERK axis, and osteosarcoma cell growth, migration, and invasion were consequently restrained. Additionally, by administering tumor cells subcutaneously to nude mice, a mouse model of transplanted tumors was created. Compared to the control group, the ZYX overexpression group's tumors were lighter and smaller, and the ZYX/Rap1 axis was activated in the ZYX overexpression group. Taken together, our results suggest that ZYX inhibits osteosarcoma cell proliferation, migration, and invasion by regulating the Rap1/MEK/ERK signaling pathway. ZYX might be crucial in the clinical management of osteosarcoma and is a promising novel therapeutic target in patients with this disease.

LncRNA SATB2-AS1 promotes tumor growth and metastasis and affects the tumor immune microenvironment in osteosarcoma by regulating SATB2

Our previous report has identified a lncRNA SATB2-AS1, which was significantly up-regulated in osteosarcoma tissue and promotes the proliferation of osteosarcoma cells in vitro. However, the mechanisms of SATB2-AS1 regulating the growth and metastasis of osteosarcoma cells in vivo and its role in the prognosis of osteosarcoma patients are still unclear. In this study, the transcriptome sequencing data of 87 patients with osteosarcoma from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database and 7 patients from our clinical center (GZFPH) was used to evaluate the importance of SATB2-AS1 and SATB2 on the prognosis. The effect of SATB2-AS1 on the growth and metastasis of osteosarcoma cells in vivo was verified by a mouse tumor model. The potential mechanisms of SATB2-AS1 regulating SATB2 were further explored by dual-luciferase reporter gene assay, RNA pull-down assay, and bioinformatics analysis. The results suggested that increased co-expression of SATB2-AS1 and SATB2 was significantly associated with poor overall survival (OS) and relapse-free survival (RFS), and was a biomarker for risk stratification in patients with osteosarcoma. Mechanistically, SATB2-AS1 promotes tumor growth and lung metastasis by regulating SATB2 in vivo. SATB2-AS1 directly binds to POU3F1 for mediating SATB2 expression in MNNG/HOS cells. In addition, SATB2-AS1 and SATB2 might be potential immunomodulators for negatively affecting immune cell infiltration by the IL-17 signaling pathway. In summary, SATB2-AS1 promoted tumor cell growth and lung metastasis by activating SATB2, thereby associated with poor prognosis in patients with osteosarcoma, which indicated that SATB2-AS1 and SATB2 might be novel biomarkers for risk stratification and promising therapeutic targets for osteosarcoma.

A Systematic Study of Anti-Osteosarcoma Mechanism of pH-Sensitive Charge-Conversion Cinnamaldehyde Polymeric Prodrug Micelles In Vitro

Osteosarcoma is an aggressive malignant neoplasm, and it is of great significance to the fabrication and investigation of the anti-tumor mechanism of nanomedicine in the treatment of osteosarcoma. Herein, a cinnamaldehyde polymeric prodrug micelle with pH-sensitive charge-conversion ability (mPEG-b-P(C7-co-CA)) was fabricated, and the anti-osteosarcoma mechanism of mPEG-b-P(C7-co-CA) micelle was investigated. mPEG-b-P(C7-co-CA) micelles were prepared by self-assembly method, and their diameter was 227 nm. mPEG-b-P(C7-co-CA) micelles could regulate the cell cycle and inhibit the proliferation of 143B cells, which was demonstrated by flow cytometry analysis, CCK-8 assay and 5-Ethynyl-2'-deoxyuridine (EdU) staining. The wound-healing assay and transwell assay showed that mPEG-b-P(C7-co-CA) micelles effectively inhibited the migration and invasion of 143B cells. It was proven that mPEG-b-P(C7-co-CA) micelles downregulated the levels of proliferation and apoptosis-related proteins and affected osteosarcoma migration and invasion by inhibiting the epithelial-mesenchymal transition (EMT). In addition, mPEG-b-P(C7-co-CA) micelles can also inhibit the transcriptional activity of the PI3K/Akt signaling pathway. Therefore, these findings provide new evidence for the pharmacological effects of mPEG-b-P(C7-co-CA) micelles.

Prospects and Advances in Adoptive Natural Killer Cell Therapy for Unmet Therapeutic Needs in Pediatric Bone Sarcomas

Malignant bone tumors are aggressive tumors, with a high tendency to metastasize, that are observed most frequently in adolescents during rapid growth spurts. Pediatric patients with malignant bone sarcomas, Ewing sarcoma and osteosarcoma, who present with progressive disease have dire survival rates despite aggressive therapy. These therapies can have long-term effects on bone growth, such as decreased bone mineral density and reduced longitudinal growth. New therapeutic approaches are therefore urgently needed for targeting pediatric malignant bone tumors. Harnessing the power of the immune system against cancer has improved the survival rates dramatically in certain cancer types. Natural killer (NK) cells are a heterogeneous group of innate effector cells that possess numerous antitumor effects, such as cytolysis and cytokine production. Pediatric sarcoma cells have been shown to be especially susceptible to NK-cell-mediated killing. NK-cell adoptive therapy confers numerous advantages over T-cell adoptive therapy, including a good safety profile and a lack of major histocompatibility complex restriction. NK-cell immunotherapy has the potential to be a new therapy for pediatric malignant bone tumors. In this manuscript, we review the general characteristics of osteosarcoma and Ewing sarcoma, discuss the long-term effects of sarcoma treatment on bones, and the barriers to effective immunotherapy in bone sarcomas. We then present the laboratory and clinical studies on NK-cell immunotherapy for pediatric malignant bone tumors. We discuss the various donor sources and NK-cell types, the engineering of NK cells and combinatorial treatment approaches that are being studied to overcome the current challenges in adoptive NK-cell therapy, while suggesting approaches for future studies on NK-cell immunotherapy in pediatric bone tumors.

Biodegradable Carbon Dioxide-Derived Non-Viral Gene Vectors for Osteosarcoma Gene Therapy

Osteosarcoma often occurs in children and adolescents with high invasiveness and high mortality. Polo-like kinase 1 (PLK1) overexpressed in most tumors promotes cancer cell proliferation and transformation. PLK1 is considered as a therapeutic target for osteosarcoma. RNA interference-based therapies are employed to combat osteosarcoma through silencing PLK1 gene expression. However, the treatment results remain unsatisfactory due to the lack of a safe and efficient nonviral gene vector. To tackle this hurdle, biodegradable and CO₂ -derivative cationic poly(vinylcyclohexene carbonates) (CPCHCs) are used as gene vectors to perform a siPLK1 therapeutic strategy for osteosarcoma treatment. Of those CPCHCs, CPCHC60 demonstrates the most excellent performance in gene transfection efficiency, endo-lysosome escaping, biodegradability, and biosafety. With the treatment of CPCHCs/siRNA nanoparticles, the expression level of PLK1 gene in osteosarcoma cells is significantly down-regulated. Subsequently, cells are arrested in the G₂ /M phase and subsequently dead in the form of apoptosis, resulting in significant tumor regression both in vitro and in vivo. This study brings a new insight into the development of superior nonviral gene vectors for practical cancer treatment. Based on the results, the resulting nanoparticle-based gene drug formation is considered to have a highly successful chance in further translational nanomedicine applications.

Development of personalized classifier based on metastasis and the immune microenvironment to predict the prognosis of osteosarcoma patients

Background

Osteosarcoma is a common malignant bone tumor with a poor prognosis. The progression and metastasis of osteosarcoma are significantly influenced by the tumor microenvironment (TME). This study aimed to develop a personalized classifier based on metastasis and immune cells in the TME to achieve better prognostic prediction in osteosarcoma.

Methods

Firstly, osteosarcoma metastasis-related differentially expressed genes (DEGs) and infiltrating immune cells in the TME were analyzed using a series of bioinformatics methods. The metastasis-related gene signature (MRS) and TME score of osteosarcoma patients were then developed. On this basis, a personalized MRS-TME classifier was constructed and validated in other clinical cohorts and different subgroups. In addition, the relationship between the MRS-related genes and the immune microenvironment was also clarified. Finally, the signaling pathways and immune response genes in osteosarcoma patients among different MRS-TME subgroups were analyzed to explore the underlying molecular mechanism.

Results

We first identified the metastasis-related DEGs in osteosarcoma, which were primarily involved in the muscle system process, calcium ion homeostasis, cell chemotaxis, and leukocyte migration. A personalized MRS-TME classifier was then constructed by integrating the MRS (10 genes) and TME (six immune cells) scores. The MRS-TME classifier demonstrated a potent capacity of predicting the survival prognosis in diverse osteosarcoma cohorts as well as in the clinical feature subgroups. The MRS score was negatively associated with the TME score, and patients in the MRS^low/TME^high subgroup exhibited a better prognosis compared to all other subgroups. Significant differences existed between the cellular signaling pathways and immune response profiles among the different MRS-TME subgroups, especially in relation to the metabolism-related biological processes and the inflammatory response.

Conclusions

The MRS-TME classifier might be a beneficial tool to aid in the prognostic evaluation and risk stratification of osteosarcoma patients.

Activity and safety of apatinib monotherapy or apatinib combined with chemotherapy for patients with metastatic or unresectable osteosarcoma over the age of 40 years: A retrospective analysis

BACKGROUND

Osteosarcoma commonly develops during childhood and adolescence. Only one-third of osteosarcoma patients have been clinically detected over the age of 40 years, and the survivorship of those patients is quite dismal. Apatinib, a novel multitarget angiogenesis inhibitor, has shown a short-term efficacy in advanced or metastatic osteosarcoma. However, the data for apatinib in the older patients with osteosarcoma are limited. We aim to evaluate the efficacy and safety of apatinib combined with chemotherapy versus apatinib monotherapy in the treatment of patients over 40 years old with metastatic or unresectable osteosarcoma.

METHODS

We retrospectively analyzed the patients with metastatic osteosarcoma who were treated with apatinib monotherapy or apatinib combined with chemotherapy between May 2015 and December 2018 in the Department of Orthopedics at West China Hospital. Apatinib was initially administered with a dose of 500 mg daily, and the dose was adjusted according to toxicity. The objective response rate (ORR), disease control rate (DCR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS) were investigated. The treatment-related adverse events and the safety of apatinib were also documented.

RESULTS

A total of 45 patients (28 men, 17 women) with metastatic or unresectable osteosarcoma were finally included, and 41 patients received at least one cycle of treatment and were evaluable for efficacy. Of 41 patients, 24 who were intolerant to intensive chemotherapy or have failed standard chemotherapy received apatinib monotherapy, and 17 patients were treated with apatinib plus chemotherapy. The median PFS and median OS were longer in the group treated with apatinib combined with chemotherapy than those of the apatinib monotherapy group (5.6 months vs. 2.6 months; 15.1 months vs. 9.7 months). Moreover, the median DOR was significantly prolonged in the group treated with apatinib combined with chemotherapy compared with that in the monotherapy group.

CONCLUSION

Apatinib demonstrated promising activity in patients over 40 years old with metastatic or unresectable osteosarcoma. The combination of apatinib and chemotherapy conferred a durable response compared with apatinib monotherapy, which might be an alternative therapeutic strategy for the management of osteosarcoma in older patients.

Non-coding RNAs as potential biomarkers in osteosarcoma

Osteosarcoma (OS) is a primary solid malignant tumor that occurs most frequently in the metaphysis of long bones. More likely to happen to children and adolescents. OS has high mortality and disability rate. However, the etiology and pathogenesis of OS have not been fully understood till now. Due to the lack of effective biomarkers, OS cannot be precisely detected in the early stage. With the application of next-generation and high-throughput sequencing, more and more abnormally expressed non-coding RNAs(ncRNAs) have been identified in OS. Growing evidences have suggested the ncRNAs, such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), have played an important role in the tumorigenesis and progression of OS. Thus, they can be served as novel biomarkers for diagnosis, treatment and prognosis. This review summarized the application of ncRNA as biomarkers in OS in detail, and discussed the limitation and future improvement of the potential biomarkers.

WeChat-platform-based education and care program as a candidate approach to relieve anxiety, depression, and post-traumatic stress disorder in parents of pediatric and adolescent patients with osteosarcoma

Background

WeChat is the main social platform in China, characterized by its versatility and ease of communication. This study aimed to explore the effect of a WeChat-platform-based education and care (WBEC) program on relieving anxiety, depression, and post-traumatic stress disorder (PTSD) in parents of pediatric and adolescent patients with osteosarcoma.

Methods

In total, 48 patients and 86 parents were enrolled in this randomized, controlled study and then assigned to the WBEC program (24 patients and 45 parents) and the usual education and care (UEC) program (22 patients and 41 parents) for 6 months as a 1:1 ratio.

Results

Parents in the WBEC group had lower Hospital Anxiety and Depression Scale (HADS) for anxiety (HADS-A) scores at M3 (7.8 ± 2.2 vs. 9.1 ± 2.5; p = 0.010) and M6 (7.7 ± 2.5 vs. 8.9 ± 2.4; p = 0.027) when compared to the UEC group, while anxiety rate was only decreased at M3 (43.2% vs. 63.4%; p = 0.049) in the WBEC group. Meanwhile, parental HADS for depression (HADS-D) scores were reduced at M3 (7.0 ± 2.0 vs. 8.0 ± 2.1; p = 0.047) and M6 (7.1 ± 1.9 vs. 8.0 ± 2.4; p = 0.045) in the WBEC group when compared with the UEC group; while depression rate remained the same. Parental Impact of Event Scale-Revised (IES-R) scores were slightly reduced among the WBEC group at M6 when compared with the UEC group [12.0 (interquartile range (IQR): 10.0–20.8] vs. 15.0 (IQR: 9.5–25.0; p = 0.077)], but not statistically significant.

Conclusion

WeChat-platform-based education and care is considered a feasible intervention to reduce anxiety and depression in parents of pediatric and adolescent patients with osteosarcoma, while also providing mild relief from PTSD.

Engineering single-atom catalysts toward biomedical applications

Due to inherent structural defects, common nanocatalysts always display limited catalytic activity and selectivity, making it practically difficult for them to replace natural enzymes in a broad scope of biologically important applications. By decreasing the size of the nanocatalysts, their catalytic activity and selectivity will be substantially improved. Guided by this concept, the advances of nanocatalysts now enter an era of atomic-level precise control. Single-atom catalysts (denoted as SACs), characterized by atomically dispersed active sites, strikingly show utmost atomic utilization, precisely located metal centers, unique metal-support interactions and identical coordination environments. Such advantages of SACs drastically boost the specific activity per metal atom, and thus provide great potential for achieving superior catalytic activity and selectivity to functionally mimic or even outperform natural enzymes of interest. Although the size of the catalysts does matter, it is not clear whether the guideline of "the smaller, the better" is still correct for developing catalysts at the single-atom scale. Thus, it is clearly a new, urgent issue to address before further extending SACs into biomedical applications, representing an important branch of nanomedicine. This review begins by providing an overview of recent advances of synthesis strategies of SACs, which serve as a basis for the discussion of emerging achievements in improving the enzyme-like catalytic properties at an atomic level. Then, we carefully compare the structures and functions of catalysts at various scales from nanoparticles, nanoclusters, and few-atom clusters to single atoms. Contrary to conventional wisdom, SACs are not the most catalytically active catalysts in specific reactions, especially those requiring multi-site auxiliary activities. After that, we highlight the unique roles of SACs toward biomedical applications. To appreciate these advances, the challenges and prospects in rapidly growing studies of SACs-related catalytic nanomedicine are also discussed in this review.