AR71

Among the many emerging strategies in precision medicine, surface receptor-directed drugs offer a promising pathway for the targeted and effective delivery of a cure. Histamine receptor (H₃R) antagonists have been demonstrated to target and effectively suppress cancer cells that overexpress H₃R. The present study aimed to evaluate the anticancer potential of (E)-3-(3,4,5-trimethoxyphenyl)-1-(4-(3-(piperidin-1-yl)propoxy)phenyl)prop-2-en-1-one (AR71), a hybrid H₃R antagonist/inverse agonist featuring a piperidinylpropoxy motif conjugated to trimethoxychalcone, which mimics colchicine and disrupts microtubule assembly. Following incubation with AR71, we observed significant inhibition of growth and cell cycle arrest at G2/M in glioblastoma and neuroblastoma cells, which correlated with their H₃R expression levels. AR71 treatment decreased the invasion potential of cancer cells by 60-80% along with a decrease in MMP-2 release. In-depth immunocytochemical investigations revealed dose-dependent impairment of microtubule organisation after treatment with AR71. Consequently, tubulin polymerisation and cytokinesis failure led to a greater incidence of aneuploid cells and tripolar mitotic events. We also observed an increase in mitochondrial reactive oxygen species in cancer cells following exposure to AR71. As a result, the mitochondrial membrane potential decreased significantly. In summary, targeting dual molecules with AR71 may create favourable conditions for the selective and synergistic action of combined anticancer compounds against glioblastoma and neuroblastoma.

Melanoma is the most aggressive form of skin cancer, with fast progression and early dissemination mediated by the melanoma inhibitory activity (MIA) protein. Here, we discovered that dimerization of MIA is required for functional activity through mutagenesis of MIA which showed the correlation between dimerization and functional activity. We subsequently identified the dodecapeptide AR71, which prevents MIA dimerization and thereby acts as a MIA inhibitor. Two-dimensional nuclear magnetic resonance (NMR) spectroscopy demonstrated the binding of AR71 to the MIA dimerization domain, in agreement with in vitro and in vivo data revealing reduced cell migration, reduced formation of metastases and increased immune response after AR71 treatment. We believe AR71 is a lead structure for MIA inhibitors. More generally, inhibiting MIA dimerization is a novel therapeutic concept in melanoma therapy.