Abstract

Ewing’s sarcoma (ES) is a highly aggressive and metastatic tumor in children and young adults caused by a chromosomal fusion between the Ewing sarcoma breakpoint region 1 (EWSR1) gene and the transcription factor FLI1 gene. ES is managed with standard treatments, including chemotherapy, surgery and radiation. Although the 5-year survival rate for primary ES has improved, the survival rate for ES patients with metastases or recurrence remains low. Several novel molecular targets in ES have recently been identified and investigated in preclinical and clinical settings, and targeting the function of receptor tyrosine kinases (RTKs), the fusion protein EWS-FLI1 and mTOR has shown promise. There has also been increasing interest in the immune responses of ES patients. Immunotherapies using T cells, NK cells, cancer vaccines and monoclonal antibodies have been considered for ES, especially for recurrent patients. Because understanding the pathogenesis of ES is extremely important for the development of novel treatments, this review focuses on the mechanisms and functions of targeted therapies and immunotherapies in ES. It is anticipated that integrating the knowledge obtained from basic research and translational and clinical studies will lead to the development of novel therapeutic strategies for the treatment of ES.

Highlights

  • Ewing’s sarcoma (ES) is an aggressive and highly metastatic malignancy predominantly afflicting young patients

  • The standard care for patients suffering from ES is based on a multimodal therapy of surgical resection associated with local radiotherapy and chemotherapy [1,2,3,4]

  • EWS-Friend leukemia virus integration site 1 (FLI1) binds the promoter of insulin-like growth factor binding protein 3 (IGFBP3) to suppress the expression of IGFBP3 which sequesters circulating IGF1 [13, 14]. These results suggest a crosstalk between the oncogenic function of EWS-FLI1 and the IGF1R signaling (Figure 1)

Read more

Summary

INTRODUCTION

Ewing’s sarcoma (ES) is an aggressive and highly metastatic malignancy predominantly afflicting young patients. Methylseleninic acid (MSA) treatment increased FOXO1 expression in the presence of EWS-FLI1, induced massive cell death and decreased xenograft tumor growth dependent on FOXO1. Treatment of ES cell lines with a specific CCKAR antagonist, devazepide, induced apoptosis in vitro and significantly reduced the tumor growth in a mouse xenograft model [104]. Combination of IGF1R and mTOR inhibitors significantly enhanced the antitumor activity in ES cells, xenografts, and ES patients, when compared to www.impactjournals.com/oncotarget either drug alone [22, 24, 112, 113]. EGR2 is a target gene of EWS-FLI1, and EGR2 knockdown inhibits ES cell proliferation, clonogenicity and spheroidal growth, and induces regression of ES xenografts [123, 124]. The combined treatments with anti-CD99 0662 monoclonal antibody and doxorubicin (DXR) were remarkably effective against both local growth and metastases of ES xenografts, and the survival rate of mice was increased [161]

CONCLUSION AND FUTURE PERSPECTIVES
Findings
CONFLICTS OF INTEREST
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call