Orally active SOX18 inhibitor with in vivo efficacy against zebrafish larvae vascular formation and breast cancer tumor lymphangiogenesis in mice.
Sm4 is an orally active SOX18 inhibitor (IC50 = 5,2 μM; COS-7 reporter assay) that directly targets SOX18 HMG domain and preferentially disrupts SOX18 interaction with a subset of binding partners (IC50 = 3.3 μM/SOX18-SOX18, 15.8 μM/SOX18-DDX17, 42.3 μM/SOX18-RBPJ, 65.9 μM/SOX18-RBPJ; IC50 ≥780 μM against SOX9 dimer or SOX18 interaction with MEF2C, NR2F2, TRIM28, ESR1), while affecting HMG-dependent DNA binding in a less potent and non-SOX18-selective manner (IC50 ∼200-220 μM for SOX15/18, IC50 ∼270-310 μM for SOX2/6/9/11). Sm4 selectively affects SOX18 target genes transcription over 7 other transcription factors by genome-wide ChIP-seq analysis as well as displays in vivo efficacy against vascular formation in zebrafish larvae (1-2 μM) and induces tumor metastasis by inhibiting angiogenesis/lymphangiogenesis in a murine model of breast cancer (25 mg/kg/d p.o.).
