Ewing sarcoma breakpoint region 1-Friend leukemia integration 1 and Paired box 3-Forkhead box O1 fusion protein-derived peptide epitopes (EWS-FLI1 and PAX3-FOXO1 epitopes)

EWS-FLI1 and PAX3-FOXO1 fusion protein-derived peptide epitopes are tumor-specific neoantigens arising from chromosomal translocations characteristic of Ewing sarcoma and alveolar rhabdomyosarcoma, respectively. The EWS-FLI1 fusion, resulting from the t(11;22)(q24;q12) translocation, and the PAX3-FOXO1 fusion, from the t(2;13)(q35;q14) translocation, create unique amino acid sequences at their fusion junctions that are not present in healthy cells (PubMed: 24507156, 28814453). These junctional peptides can be processed and presented by Major Histocompatibility Complex (MHC) molecules on the surface of tumor cells, making them ideal targets for T-cell-based immunotherapies (PubMed: 28103458). Therapeutic approaches include the development of peptide vaccines, such as the autologous Vigil (Gemogenovatucel-T) vaccine, and engineered T-cell receptor (TCR-T) therapies designed to recognize these specific MHC-peptide complexes (PubMed: 32433833). By targeting these neoantigens, clinicians aim to stimulate a precise cytotoxic T-lymphocyte response against the malignant cells while sparing normal tissues. However, challenges remain regarding the low immunogenicity of these peptides and the requirement for specific HLA alleles, such as HLA-A*02:01, for effective presentation.

Other names

EWS-FLI1 junctional peptidesPAX3-FOXO1 junctional peptidesEwing sarcoma neoantigensAlveolar rhabdomyosarcoma neoantigenst(11;22) and t(2;13) fusion epitopes

Induction of tumor-specific cytotoxic T-lymphocyte (CTL) responses through the recognition of MHC-presented neoantigenic peptide sequences derived from the fusion junctions of oncogenic proteins.