Optimization of hit BC-DXI-04 (IC50 = 40.1 μM) provided new potent sulfonamide based AIMP2-DX2 inhibitors.?Among these, BC-DXI-843 showed improved inhibition against AIMP2-DX2 (IC50 = 0.92 μM) with more than 100-fold selectivity over AIMP2 in a luciferase assay.?Several binding assays indicated that this compound effectively induces cancer cell apoptosis by specifically interrupting the interaction between DX2 and HSP70, which leads to the degradation of DX2 via Siah1-mediated ubiquitination.

BC-DXI-843 demonstrated in vivo efficacy in a tumor xenograft mouse model (H460 cells) at a dosage of 50 mg/kg, suggesting it as a promising lead for development of novel therapeutics targeting AIMP2-DX2 in lung cancer.