Numerous strategies have been developed over the years to circumvent MDR. Of these, the discovery and implementation of P-gp and MRP1 inhibitors have been most extensively studied. However, these inhibitors have not been able to be used clinically. While research continues in this area, it must also be acknowledged that other avenues must be explored.
Recently, the novel ¡®non-genetic?acquisition of P-gp-mediated MDR by microparticles (MPs) has been reported. MPs are vesicles 0.1-1 ¦Ìm in diameter that are released via plasma membrane blebbing. They are important mediators of inflammation, coagulation and vascular homeostasis. In addition to surface P-gp protein, MPs also carry various nucleic acid species as cargo. This ¡®non-genetic?intercellular transfer provides an alternative pathway for the cellular acquisition and dissemination of traits and implicates MPs as important mediators in the spread of MDR and provides a novel pathway for the circumvention of MDR.