PFI-90，50MG，SML4130-50MG，Sigma

Biochem/physiol Actions

selective KDM3B inhibitor, disrupts PAX3-FOXO1 mediated transcription in FP-RMS.

PFI-90 directly targets and binds to metal ions in KDMs′ active sites, showing a strong preference for KDM3B (KD = 7.68 μM) while demonstrating minimal effect on other histone demethylases like KDM1A, KDM4B, KDM5A, KDM6B, HDAC1, HDAC2, HDAC3, and PRMT5. This selectivity leads to increased methylation at H3K4 and H3K9, disrupting the transcription of PAX3-FOXO1 oncogene targets in fusion-positive rhabdomyosarcoma (FP-RMS). PFI 90 effectively inhibits growth in PAX3-FOXO1 positive RMS cell lines (SCMC, RH4, RH30) with EC50 = 0.4, 0.9 and 3.2 µM, respectively. PFI-90 suppresses PAX3-FOXO1 function, inducing apoptosis and reducing RNA Pol2 activity without affecting PAX3-FOXO1 protein levels or DNA binding. Its treatment hampers FP-RMS tumor growth in vivo, offering a promising therapeutic avenue by selectively targeting KDM3B to combat FP-RMS.