EWS/FLI-l peptide-pulsed dendritic cells induces the antitumor immunity in a murine Ewing's sarcoma cell model

Signaling pathways and targeted therapies in Ewing sarcoma

Ewing sarcoma, the second most prevalent malignant bone tumor with potential occurrence in soft tissues, exhibits a high level of aggressiveness, primarily afflicting children and adolescents. It is characterized by fusion proteins arising from chromosomal translocations. The fusion proteins induce aberrations in multiple signaling pathways and molecules, constituting a key event in oncogenic transformation. While diagnostic and therapeutic modalities have advanced in recent decades and multimodal treatments, including surgery, radiotherapy, and chemotherapy, have significantly improved survival of patients with localized tumors, patients with metastatic tumors continue to face poor prognoses. There persists a pressing need for novel alternative treatments, yet the translation of our understanding of Ewing sarcoma pathogenesis into improved clinical outcomes remains a critical challenge. Here, we provide a comprehensive review of Ewing sarcoma, including fusion proteins, various signaling pathways, pivotal pathogenetic molecules implicated in its development, and associated targeted therapies and immunotherapies. We summarize past endeavors, current advancements, and deliberate on limitations and future research directions. It is envisaged that this review will furnish novel insights into prospective treatment avenues for Ewing sarcoma.

Advancements in osteosarcoma management: integrating immune microenvironment insights with immunotherapeutic strategies

Osteosarcoma, a malignant bone tumor predominantly affecting children and adolescents, presents significant therapeutic challenges, particularly in metastatic or recurrent cases. Conventional surgical and chemotherapeutic approaches have achieved partial therapeutic efficacy; however, the prognosis for long-term survival remains bleak. Recent studies have highlighted the imperative for a comprehensive exploration of the osteosarcoma immune microenvironment, focusing on the integration of diverse immunotherapeutic strategies-including immune checkpoint inhibitors, tumor microenvironment modulators, cytokine therapies, tumor antigen-specific interventions, cancer vaccines, cellular therapies, and antibody-based treatments-that are directly pertinent to modulating this intricate microenvironment. By targeting tumor cells, modulating the tumor microenvironment, and activating host immune responses, these innovative approaches have demonstrated substantial potential in enhancing the effectiveness of osteosarcoma treatments. Although most of these novel strategies are still in research or clinical trial phases, they have already demonstrated significant potential for individuals with osteosarcoma, suggesting the possibility of developing new, more personalized and effective treatment options. This review aims to provide a comprehensive overview of the current advancements in osteosarcoma immunotherapy, emphasizing the significance of integrating various immunotherapeutic methods to optimize therapeutic outcomes. Additionally, it underscores the imperative for subsequent research to further investigate the intricate interactions between the tumor microenvironment and the immune system, aiming to devise more effective treatment strategies. The present review comprehensively addresses the landscape of osteosarcoma immunotherapy, delineating crucial scientific concerns and clinical challenges, thereby outlining potential research directions.

Managing the immune microenvironment of osteosarcoma: the outlook for osteosarcoma treatment

Osteosarcoma, with poor survival after metastasis, is considered the most common primary bone cancer in adolescents. Notwithstanding the efforts of researchers, its five-year survival rate has only shown limited improvement, suggesting that existing therapeutic strategies are insufficient to meet clinical needs. Notably, immunotherapy has shown certain advantages over traditional tumor treatments in inhibiting metastasis. Therefore, managing the immune microenvironment in osteosarcoma can provide novel and valuable insight into the multifaceted mechanisms underlying the heterogeneity and progression of the disease. Additionally, given the advances in nanomedicine, there exist many advanced nanoplatforms for enhanced osteosarcoma immunotherapy with satisfactory physiochemical characteristics. Here, we review the classification, characteristics, and functions of the key components of the immune microenvironment in osteosarcoma. This review also emphasizes the application, progress, and prospects of osteosarcoma immunotherapy and discusses several nanomedicine-based options to enhance the efficiency of osteosarcoma treatment. Furthermore, we examine the disadvantages of standard treatments and present future perspectives for osteosarcoma immunotherapy.

Role of immunotherapy in Ewing sarcoma

Ewing sarcoma (ES) is thought to arise from mesenchymal stem cells and is the second most common bone sarcoma in pediatric patients and young adults. Given the dismal overall outcomes and very intensive therapies used, there is an urgent need to explore and develop alternative treatment modalities including immunotherapies. In this article, we provide an overview of ES biology, features of ES tumor microenvironment (TME) and review various tumor-associated antigens that can be targeted with immune-based approaches including cancer vaccines, monoclonal antibodies, T cell receptor-transduced T cells, and chimeric antigen receptor T cells. We highlight key reasons for the limited efficacy of various immunotherapeutic approaches for the treatment of ES to date. These factors include absence of human leukocyte antigen class I molecules from the tumor tissue, lack of an ideal surface antigen, and immunosuppressive TME due to the presence of myeloid-derived suppressor cells, F2 fibrocytes, and M2-like macrophages. Lastly, we offer insights into strategies for novel therapeutics development in ES. These strategies include the development of gene-modified T cell receptor T cells against cancer–testis antigen such as XAGE-1, surface target discovery through detailed profiling of ES surface proteome, and combinatorial approaches. In summary, we provide state-of-the-art science in ES tumor immunology and immunotherapy, with rationale and recommendations for future therapeutics development.

Case Report: Immune-mediated Complete Response in a Patient With Recurrent Advanced Ewing Sarcoma (EWS) After Vigil Immunotherapy

Ewing sarcoma is a highly resistant disease with a <10% chance of survival at 5 years after failure of frontline chemotherapy. This is a case report of an Ewing sarcoma patient with metastatic disease recurrence <2 years after standard chemotherapy/radiation who achieved a durable and sustained complete response after 2 series of treatments with Vigil (GMCSF/bi-shRNA furin DNA autologous tumor immunotherapy) serially manufactured from first and second recurrences with ELISPOT assay correlation. Results support justification of further testing of Vigil with ELISPOT assay as a biomarker to assess level of immune response and correlation with disease control.