[CAS NO. 1426138-42-2]  FX1

FX1 disrupted formation of the BCL6 repression complex, reactivated BCL6 target genes, and mimicked the phenotype of mice engineered to express BCL6 with corepressor binding site mutations. FX1 suppressed ABC-DLBCL cells in vitro and in vivo, as well as primary human ABC-DLBCL specimens ex vivo. FX1 is specific to BCL6 and binds with a greater affinity than the natural BCL6 ligand SMRT. FX1 almost invariantly induced significant derepression of these genes(BCL6 target genes CASP8, CD69, CXCR4, CDKN1A, and DUSP5) as compared with vehicle in 2 independent DLBCL cell lines. FX1 was more than 100-fold more powerful than the previous generation of BCL6 inhibitors represented by 79-6, and 300-fold more potent than the recently reported binding of the antibiotics rifamycin and rifabutin (KD ~1 mM).