PAX3-FOXO1 fusion protein-derived neoantigen peptide (PAX3-FOXO1 neoantigen)

PAX3-FOXO1 fusion protein-derived neoantigen peptides are short amino acid sequences that span the unique breakpoint junction of the PAX3-FOXO1 chimeric oncoprotein. This fusion protein is the hallmark of alveolar rhabdomyosarcoma (ARMS), resulting from a reciprocal chromosomal translocation, t(2;13)(q35;q14), which occurs in approximately 60-80% of cases (Shern et al., 2014, Cancer Discovery). Because the amino acid sequence at the fusion junction is entirely absent from the normal human proteome, these peptides function as highly specific tumor-specific antigens (TSAs) or neoantigens. When these peptides are processed and presented by Human Leukocyte Antigen (HLA) molecules on the tumor cell surface, they can be targeted by the immune system, specifically by cytotoxic T lymphocytes (Gattenloehner et al., 1998, Blood). Therapeutic strategies leveraging these neoantigens include the development of peptide-based vaccines and engineered T-cell receptor (TCR-T) therapies designed to induce a potent, selective anti-tumor immune response (Mackall et al., 2008, J Clin Oncol). While these targets offer high specificity and minimal off-tumor toxicity, their clinical utility is often constrained by the requirement for specific HLA alleles (such as HLA-B7) and potential tumor escape through HLA downregulation. Research continues to focus on identifying more immunogenic epitopes and expanding the range of compatible HLA types to broaden the eligible patient population (Orentas et al., 2012, Front Oncol).

Other names

PAX3-FKHR fusion peptidePAX3-FOXO1 breakpoint peptideAlveolar rhabdomyosarcoma fusion neoantigenPAX3-FOXO1 junctional peptide

These peptides are processed and presented by MHC/HLA molecules on the surface of tumor cells, where they are recognized by specific T-cell receptors (TCRs) on cytotoxic T lymphocytes, leading to selective tumor cell lysis.