A novel 2-iminobenzimidazole compound, XYA1353, displays in vitro and in vivo anti-myeloma activity via targeting NF-κB signaling

Multiple myeloma (MM) is an accumulated disease of malignant plasma cells, which is still incurably owing to therapeutic resistance and disease relapse. Herein, we synthesized a novel 2-iminobenzimidazole compound, XYA1353, showing a potent anti-myeloma activity both in vitro and in vivo. Compound XYA1353 dose-dependently promoted MM cell apoptosis via activating caspase-dependent endogenous pathways. Moreover, compound XYA1353 could enhance bortezomib (BTZ)-mediated DNA damage via elevating γH2AX expression levels. Notably, compound XYA1353 interacted synergistically with BTZ and overcame drug resistance. RNA sequencing analysis and experiments confirmed that compound XYA1353 inhibited primary tumor growth and myeloma distal infiltration by disturbing canonical NF-κB signaling pathway via decreasing expression of P65/P50 and p-IκBα phosphorylation level. Due to its importance in regulating MM progression, compound XYA1353 alone or combined with BTZ may potentially exert therapeutic effects on multiple myeloma by suppressing canonical NF-κB signaling.

Discovery of small molecule c-Maf inhibitors using molecular docking-based virtual screening, molecular dynamics simulation, and biological evaluation

Multiple myeloma (MM) is a prevalent plasma cell malignancy in the blood system that remains incurable. Given the abnormally high expression of c-Maf in most MM patients, targeting c-Maf presents an attractive therapeutic approach for treating MM malignancies. In this study, we employed a combined strategy involving molecular docking-based virtual screening, molecular dynamics (MD) simulation, and molecular mechanics/generalized Born surface area (MM/GBSA) free energy calculation on existing FDA-approved drugs. Six compounds were selected for further experimental assay: vemurafenib, sorafenib, sildenafil, fluvastatin, erlotinib, and glimepiride. Among these compounds, sorafenib and glimepiride exhibited significant inhibition of myeloma cell proliferation in the RPMI-8226 cell line. Moreover, both compounds simultaneously downregulated c-Maf protein expression to induce G1 phase arrest and apoptosis in myeloma cells. Collectively, sorafenib and glimepiride may be considered promising candidates for developing more potent c-Maf inhibitors in the future.