Paired box 7-Forkhead box O1 fusion protein (PAX7-FOXO1)

The Paired box 7-Forkhead box O1 (PAX7-FOXO1) fusion protein is a chimeric transcription factor resulting from the t(1;13)(p36;q14) chromosomal translocation (Source: PubMed, PMID: 15507670). This fusion is a hallmark of a subset of alveolar rhabdomyosarcoma (ARMS), a highly aggressive pediatric soft tissue sarcoma (Source: National Cancer Institute). The protein combines the DNA-binding domains of PAX7 with the transactivation domain of FOXO1, creating a potent oncogenic driver that dysregulates gene expression (Source: UniProt, P23759). It promotes cell survival and proliferation while blocking the normal myogenic differentiation of muscle progenitor cells (Source: PubMed, PMID: 24658273). Because transcription factors like PAX7-FOXO1 lack traditional small-molecule binding pockets, they are often considered "undruggable" (Source: Nature Reviews Drug Discovery). Current therapeutic research focuses on indirect approaches, such as using HDAC inhibitors like Entinostat or BET inhibitors like JQ1 to disrupt the epigenetic landscape required for its activity (Source: ClinicalTrials.gov, NCT03534934). Additionally, targeting downstream signaling nodes like IGF1R and MET is a common strategy to mitigate its oncogenic effects (Source: PubMed, PMID: 17210688).

Other names

PAX7-FKHRt(1;13)(p36;q14) fusion proteinPaired box protein Pax-7/Forkhead box protein O1 fusionPAX7/FOXO1

Indirect inhibition of transcriptional activity through the modulation of chromatin accessibility (e.g., HDAC or BET inhibition) or the blockade of downstream oncogenic signaling pathways (Source: PubMed, PMID: 28431144).