Transcription factor PU.1 (SPI1)

Transcription factor PU.1 (SPI1) is an ETS-domain nuclear protein encoded by the SPI1 gene. It binds to purine-rich regulatory sequences (PU-boxes) within target gene enhancers, orchestrating gene expression programs essential for differentiation and function of myeloid and B-lymphoid cells. PU.1 mediates hematopoiesis by modulating the transcription of genes regulating cell fate, proliferation, apoptosis, immune cell activation, and cytokine production, interacting with cofactors such as GATA-1, GATA-2, c-Jun, and SWI/SNF complexes. Aberrant expression, mutation, or dysregulation of SPI1 has been implicated in the pathogenesis of several hematological and solid malignancies, fibrotic disorders, neurodegenerative diseases, and inflammatory states. High expression of SPI1 can serve as a poor prognostic marker in cancer and as a potential immunotherapeutic target. Safety risks arise from the critical homeostatic functions of PU.1 in the immune system and blood cell formation, making direct pharmacological targeting challenging.

Other names

Spi-1 proto-oncogenePU.1SPI1SPI-ASFPI131 kDa-transforming proteinhematopoietic transcription factor PU.1AGM10spleen focus forming virus (SFFV) proviral integration oncogene spi1

Drugs or molecular strategies (e.g., siRNA, inhibitors, antisense oligonucleotides) could hypothetically inhibit SPI1 function or expression to block its transcriptional regulatory activity. Currently, no approved drugs specifically target SPI1; however, its modulation can impact hematopoietic cell survival, differentiation, and tumor progression indirectly