Immune infiltrate and tumor microenvironment transcriptional programs stratify pediatric osteosarcoma into prognostic groups at diagnosis

From biology to personalized medicine: recent knowledge in Osteosarcoma

High-grade osteosarcoma is the most common paediatric bone cancer. More than one third of patients relapse and die of osteosarcoma using current chemotherapeutic and surgical strategies. To improve outcomes in osteosarcoma, two crucial challenges need to be tackled: 1-the identification of hard-to-treat disease, ideally from diagnosis; 2- choosing the best combined or novel therapies to eradicate tumor cells which are resistant to current therapies leading to disease dissemination and metastasize as well as their favorable microenvironment. Genetic chaos, tumor complexity and heterogeneity render this task difficult. The development of new technologies like next generation sequencing has led to an improvement in osteosarcoma oncogenesis. This review summarizes recent biological and therapeutical advances in osteosarcoma, as well as the challenges that must be overcome in order to develop personalized medicine and new therapeutic strategies and ultimately improve patient survival.

IL-1 Family Members in Bone Sarcomas

IL-1 family members have multiple pleiotropic functions affecting various tissues and cells, including the regulation of the immune response, hematopoietic homeostasis, bone remodeling, neuronal physiology, and synaptic plasticity. Many of these activities are involved in various pathological processes and immunological disorders, including tumor initiation and progression. Indeed, IL-1 family members have been described to contribute to shaping the tumor microenvironment (TME), determining immune evasion and drug resistance, and to sustain tumor aggressiveness and metastasis. This review addresses the role of IL-1 family members in bone sarcomas, particularly the highly metastatic osteosarcoma (OS) and Ewing sarcoma (EWS), and discusses the IL-1-family-related mechanisms that play a role in bone metastasis development. We also consider the therapeutic implications of targeting IL-1 family members, which have been proposed as (i) relevant targets for anti-tumor and anti-metastatic drugs; (ii) immune checkpoints for immune suppression; and (iii) potential antigens for immunotherapy.

Polydopamine-cloaked Fe-based metal organic frameworks enable synergistic multidimensional treatment of osteosarcoma

One of the major challenges in effective cancer therapy arises because of the hypoxic microenvironment in the tumor. This compromises the efficacy of both chemo- and radiotherapy, and thus hinders patient outcomes. To solve this problem, we constructed polydopamine (PDA)-cloaked Fe-based metal organic frameworks (MOFs) loaded with d-arginine (d-Arg), glucose oxidase (GOX), and the chemotherapeutic drug tirapazamine (TPZ). These offer simultaneous multifaceted therapy combining chemodynamic therapy (CDT)/radiotherapy (RT)/starvation therapy (ST)/gas therapy (GT) and chemotherapy. The particles further can act as contrast agents in magnetic resonance imaging. GOX catalyses the conversion of endogenous glucose and O2 to hydrogen peroxide and gluconic acid, blocking the cells' energy supply and providing ST. With the resultant acidification of the local environment, the breakdown of the MOF releases TPZ (for chemotherapy) and Fe3+, which reacts with H2O2 to produce reactive oxygen species and thus stimulates the conversion of d-Arg to NO for GT and RT sensitization. The PDA coating not only seals the pores and chelates Fe3+ to enhance the T1-weighted magnetic resonance imaging (MRI) properties, but also is used to graft folate bovine serum albumin (FA-BSA) and thereby target the tumor site. The combined administration of low doses of X-ray irradiation and nanoparticles reduces the side effects on healthy tissue and can prevent lung metastases in mice. This work highlights the synergistic treatment of osteosarcoma via ST/GT/CDT/RT/MRI/ chemotherapy using a PDA-cloaked MOF system.

Decoding the Impact of Tumor Microenvironment in Osteosarcoma Progression and Metastasis

Osteosarcoma (OS) is a heterogeneous, highly metastatic bone malignancy in children and adolescents. Despite advancements in multimodal treatment strategies, the prognosis for patients with metastatic or recurrent disease has not improved significantly in the last four decades. OS is a highly heterogeneous tumor; its genetic background and the mechanism of oncogenesis are not well defined. Unfortunately, no effective molecular targeted therapy is currently available for this disease. Understanding osteosarcoma's tumor microenvironment (TME) has recently gained much interest among scientists hoping to provide valuable insights into tumor heterogeneity, progression, metastasis, and the identification of novel therapeutic avenues. Here, we review the current understanding of the TME of OS, including different cellular and noncellular components, their crosstalk with OS tumor cells, and their involvement in tumor progression and metastasis. We also highlight past/current clinical trials targeting the TME of OS for effective therapies and potential future therapeutic strategies with negligible adverse effects.

A TLR4 Agonist Induces Osteosarcoma Regression by Inducing an Antitumor Immune Response and Reprogramming M2 Macrophages to M1 Macrophages

Osteosarcoma (OsA) has limited treatment options and stagnant 5-year survival rates. Its immune microenvironment is characterized by a predominance of tumor-associated macrophages (TAMs), whose role in OsA progression remain unclear. Nevertheless, immunotherapies aiming to modulate macrophages activation and polarization could be of interest for OsA treatment. In this study, the antitumor effect of a liposome-encapsulated chemically detoxified lipopolysaccharide (Lipo-MP-LPS) was evaluated as a therapeutic approach for OsA. Lipo-MP-LPS is a toll-like receptor 4 (TLR4) agonist sufficiently safe and soluble to be IV administered at effective doses. Lipo-MP-LPS exhibited a significant antitumor response, with tumor regression in 50% of treated animals and delayed tumor progression in the remaining 50%. The agent inhibited tumor growth by 75%, surpassing the efficacy of other immunotherapies tested in OsA. Lipo-MP-LPS modulated OsA's immune microenvironment by favoring the transition of M2 macrophages to M1 phenotype, creating a proinflammatory milieu and facilitating T-cell recruitment and antitumor immune response. Overall, the study demonstrates the potent antitumor effect of Lipo-MP-LPS as monotherapy in an OsA immunocompetent model. Reprogramming macrophages and altering the immune microenvironment likely contribute to the observed tumor control. These findings support the concept of immunomodulatory approaches for the treatment of highly resistant tumors like OsA.

Identification and validation of novel biomarkers associated with immune infiltration for the diagnosis of osteosarcoma based on machine learning

Objectives: Osteosarcoma is the most common primary malignant tumor in children and adolescents, and the 5-year survival of osteosarcoma patients gained no substantial improvement over the past decades. Effective biomarkers in diagnosing osteosarcoma are warranted to be developed. This study aims to explore novel biomarkers correlated with immune cell infiltration in the development and diagnosis of osteosarcoma. Methods: Three datasets (GSE19276, GSE36001, GSE126209) comprising osteosarcoma samples were extracted from Gene Expression Omnibus (GEO) database and merged to obtain the gene expression. Then, differentially expressed genes (DEGs) were identified by limma and potential biological functions and downstream pathways enrichment analysis of DEGs was performed. The machine learning algorithms LASSO regression model and SVM-RFE (support vector machine-recursive feature elimination) analysis were employed to identify candidate hub genes for diagnosing patients with osteosarcoma. Receiver operating characteristic (ROC) curves were developed to evaluate the discriminatory abilities of these candidates in both training and test sets. Furthermore, the characteristics of immune cell infiltration in osteosarcoma, and the correlations between these potential genes and immune cell abundance were illustrated using CIBERSORT. qRT-PCR and western blots were conducted to validate the expression of diagnostic candidates. Results: GEO datasets were divided into the training (merged GSE19276, GSE36001) and test (GSE126209) groups. A total of 71 DEGs were screened out in the training set, including 10 upregulated genes and 61 downregulated genes. These DEGs were primarily enriched in immune-related biological functions and signaling pathways. After machine learning by SVM-RFE and LASSO regression model, four biomarkers were chosen for the diagnostic nomogram for osteosarcoma, including ASNS, CD70, SRGN, and TRIB3. These diagnostic biomarkers all possessed high diagnostic values (AUC ranging from 0.900 to 0.955). Furthermore, these genes were significantly correlated with the infiltration of several immune cells, such as monocytes, macrophages M0, and neutrophils. Conclusion: Four immune-related candidate hub genes (ASNS, CD70, SRGN, TRIB3) with high diagnostic value were confirmed for osteosarcoma patients. These diagnostic genes were significantly connected with the immune cell abundance, suggesting their critical roles in the osteosarcoma tumor immune microenvironment. Our study provides highlights on novel diagnostic candidate genes with high accuracy for diagnosing osteosarcoma patients.

Cytokines as Prognostic Biomarkers in Osteosarcoma Patients: A Systematic Review and Meta-analysis

Osteosarcoma is the most prevalent type of primary bone malignancy in children and adolescents. The effect of cytokines on osteosarcoma prognosis has been studied and reported. This meta-analysis aimed to assess the prognostic value of cytokines as osteosarcoma biomarkers. Databases including PubMed, Embase, and Cochrane Library were searched for studies on the prognostic value of cytokines in osteosarcoma. From the eligible studies, data on overall survival (OS), disease-free survival, and metastasis-free survival (MFS) were extracted. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. A total of 11 studies involving 755 patients were included in this analysis. High macrophage migration inhibitory factor (MIF) expression in tumors was significantly associated with shortened OS (HR = 2.01, 95% CI: 1.18-3.42, P = 0.010) and MFS (HR = 2.51, 95% CI: 1.47-4.01, P = 0.001). Elevated T cell immunoglobulin and mucin domain-3 (Tim-3) levels in serum correlated with increased risk of disease progression in patients with osteosarcoma (HR = 3.14, 95% CI: 2.88-3.03, P < 0.001). However, interleukin 6 (IL-6) and tumor necrosis factor were not substantially associated with osteosarcoma prognosis. Owing to a paucity of research, other relevant cytokines [interferon-α/β receptor, tissue factor, macrophage inhibitory cytokine 1 (MIC-1), and IL-23] could not be combined. In conclusion, MIF levels in tumors and Tim-3 levels in serum can be potential biomarkers of poor prognosis in osteosarcoma. To confirm this finding and implement these biomarkers into clinical applications, additional large-scale, high-quality studies are needed.

Longitudinal characterization of primary osteosarcoma and derived subcutaneous and orthotopic relapsed patient-derived xenograft models

Osteosarcoma is a rare bone cancer in adolescents and young adults with a dismal prognosis because of metastatic disease and chemoresistance. Despite multiple clinical trials, no improvement in outcome has occurred in decades. There is an urgent need to better understand resistant and metastatic disease and to generate in vivo models from relapsed tumors. We developed eight new patient-derived xenograft (PDX) subcutaneous and orthotopic/paratibial models derived from patients with recurrent osteosarcoma and compared the genetic and transcriptomic landscapes of the disease progression at diagnosis and relapse with the matching PDX. Whole exome sequencing showed that driver and copy-number alterations are conserved from diagnosis to relapse, with the emergence of somatic alterations of genes mostly involved in DNA repair, cell cycle checkpoints, and chromosome organization. All PDX patients conserve most of the genetic alterations identified at relapse. At the transcriptomic level, tumor cells maintain their ossification, chondrocytic, and trans-differentiation programs during progression and implantation in PDX models, as identified at the radiological and histological levels. A more complex phenotype, like the interaction with immune cells and osteoclasts or cancer testis antigen expression, seemed conserved and was hardly identifiable by histology. Despite NSG mouse immunodeficiency, four of the PDX models partially reconstructed the vascular and immune-microenvironment observed in patients, among which the macrophagic TREM2/TYROBP axis expression, recently linked to immunosuppression. Our multimodal analysis of osteosarcoma progression and PDX models is a valuable resource to understand resistance and metastatic spread mechanisms, as well as for the exploration of novel therapeutic strategies for advanced osteosarcoma.

IL-10 and TNFα are associated with decreased survival in low-risk pediatric acute myeloid leukemia; a children's oncology group report

Pediatric acute myeloid leukemia (AML) is a devastating disease with a high risk of relapse. Current risk classification designates patients as high or low risk (LR) based on molecular features and therapy response. However, 30% of LR patients still suffer relapse, indicating a need for improvement in risk stratification. Cytokine levels, such as IL-6 and IL-10, have been shown to be prognostic in adult AML but have not been well studied in children. Previously, we reported elevated IL-6 levels in pediatric AML bone marrow to be associated with inferior prognosis. Here, we expanded our investigation to assess cytokine levels in diagnostic peripheral blood plasma (PBP) of pediatric AML patients and determined correlation with outcome. Diagnostic PBP was obtained from 80 patients with LR AML enrolled on the Children's Oncology Group AAML1031 study and normal PBP from 11 controls. Cytokine levels were measured and correlation with clinical outcome was assessed. IL-6, TNFα, MIP-3a, and IL-1β were significantly higher in AML patients versus controls when corrected by the Bonferroni method. Furthermore, elevated TNFα and IL-10 were significantly associated with inferior outcomes. Our data demonstrate that in diagnostic PBP of LR pediatric AML patients, certain cytokine levels are elevated as compared to healthy controls and that elevated TNFα and IL-10 are associated with inferior outcomes, supporting the idea that an abnormal inflammatory state may predict poor outcomes. Studies are needed to determine the mechanisms by which these cytokines impact survival, and to further evaluate their use as prognostic biomarkers in pediatric AML.

Strategies to Overcome Resistance to Immune-Based Therapies in Osteosarcoma

Improving the prognosis and cure rate of HGOSs (high-grade osteosarcomas) is an absolute need. Immune-based treatment approaches have been increasingly taken into consideration, in particular for metastatic, relapsed and refractory HGOS patients, to ameliorate the clinical results currently achieved. This review is intended to give an overview on the immunotherapeutic treatments targeting, counteracting or exploiting the different immune cell compartments that are present in the HGOS tumor microenvironment. The principle at the basis of these strategies and the possible mechanisms that HGOS cells may use to escape these treatments are presented and discussed. Finally, a list of the currently ongoing immune-based trials in HGOS is provided, together with the results that have been obtained in recently completed clinical studies. The different strategies that are presently under investigation, which are generally aimed at abrogating the immune evasion of HGOS cells, will hopefully help to indicate new treatment protocols, leading to an improvement in the prognosis of patients with this tumor.

Together Intra-Tumor Hypoxia and Macrophagic Immunity Are Driven Worst Outcome in Pediatric High-Grade Osteosarcomas

Simple Summary

Radiological and immunohistochemical data were correlated with the outcome in a retrospective monocentric cohort of 30 pediatric osteosarcomas (OTS). A necrotic volume of more than 50 cm³ at diagnosis was significantly linked to a worse overall survival (OS). Regarding immunohistochemical analyses, an overexpression of hypoxic markers, such as HIF-1α and anhydrase carbonic IX (CAIX), was significantly linked to a worse OS, while pS6-RP hyperexpression was correlated with a better survival. We also featured that CD68 positive cells, representative of macrophagic M1 polarization, were mostly associated with HIF-1α and CAIX hyperexpressions and that M2-like polarization, mostly related to CD163 positivity, was correlated to mTor activation. These findings, involving clinical, radiological and biology data, allowed us to hypothesize a dual signature association ready to use routinely in future protocols.

Abstract

Background: Osteosarcomas (OTS) represent the most common primary bone cancer diagnosed in adolescents and young adults. Despite remarkable advances, there are no objective molecular or imaging markers able to predict an OTS outcome at diagnosis. Focusing on biomarkers contributing broadly to treatment resistance, we examine the interplay between the tumor-associated macrophages and intra-tumor hypoxia. Methods: Radiological and immunohistochemical (IHC) data were correlated with the outcome in a retrospective and monocentric cohort of 30 pediatric OTS. We studied hypoxic (pS6, phospho-mTor, HIF-1α and carbonic anhydrase IX (CAIX)) and macrophagic (CD68 and CD163) biomarkers. Results: The imaging analyses were based on MRI manual volumetric measures on axial post-contrast T1 weighted images, where, for each tumor, we determined the necrotic volume and its ratio to the entire tumor volume. When they were above 50 cm³ and 20%, respectively, they correlated with a worse overall survival (p = 0.0072 and p = 0.0136, respectively) and event-free survival (p = 0.0059 and p = 0.0143, respectively). IHC assessments enable a significant statistical link between HIF-1α/CAIX hyper-expressions, CD68+ cells and a worse outcome, whereas activation of mTor pathway was linked to a better survival rate and CD163+ cells. Conclusions: This study evidenced the links between hypoxia and immunity in OTS, as their poor outcome may be related to a larger necrotic volume on diagnostic MRI and, in biopsies, to a specific IHC profile.