Effect of mitoxantrone liposomes on multidrug-resistant breast cancer cells

A major obstacle in efficacy of breast cancer chemotherapy is the emergence of multidrug resistance. We investigated modulation of multidrug resistanc e by liposome-encapsulated mitoxantrone in a drug resistant human breast MC F7R cell line and the influence of liposome composition Neutral high phase- transition temperature and anionic low phase-transition temperature phospho lipid liposomes, reduced the resistance factor from 142 to 15 and 38, respe ctively. The higher cytotoxicity obtained with mitoxantrone-encapsulation w as not necessarily related to higher intracellular uptake. Our data suggest that liposomes, according to their lipid composition,may alter the P-glyco protein function by plasma,membrane stabilization and modulate multidrug re sistance in human cancer.