Aptamer inhibits P-glycoprotein efflux function via the Wnt/β-catenin signaling pathway.

Inhibiting permeability glycoprotein (P-gp) efflux is a strategy to enhance drug efficacy or overcome multidrug resistance in tumors. However, whether P-gp aptamer (APT, an 81 bp ssDNA) inhibits P-gp efflux is unknown. Increased Rho123 uptake was observed in the rat brain and intestine. Bidirectional transport of Rho123 indicated that 100 nM of APT inhibited P-gp activity with inhibition ratios of 75.0 % in Caco-2 and 60.5 % in hCMEC/D3 cells. The apparent permeability coefficients (P) from the apical (AP) to basolateral (BL) sides significantly increased by 129.4 % in Caco-2 and 8.0 % in hCMEC/D3 cells, respectively. The P from the BL→AP sides in the two cell lines decreased. P-gp mRNA and protein expression in the rat ileum, brain, and two cell lines markedly decreased following APT exposure. APT downregulated Wnt3, pho-Dvl2, β-catenin expression and decreased the ratio of pho-GSK-3β to GSK-3β in the rat ileum and brain. Molecular docking analysis suggested that APT interact with Wnt/β-catenin signaling pathway proteins at various amino acid sites. The present study reports a novel a novel nucleic acid-based P-gp inhibitor, which may benefit for enhancing drug efficacy or overcome multidrug resistance in clinical application.