RESUMEN
INTRODUCTION: Hepatocellular carcinoma is the most common liver malignancy and the third leading cause of cancer death worldwide. One crucial limitation in the pharmacotherapy for this tumour is its chemotherapy-resistant nature produced by the overexpression of several members of the ATP-binding cassette protein family that efflux drugs out of cells, as observed with the breast cancer resistant protein (BCRP). OBJECTIVES: This study aimed to assess the ability of Pluronic® F127 to reverse the multidrug resistance phenotype in two human hepatocellular cell lines. METHODS: PLC/PRF/5 and SKHep1 cells were exposed to Pluronic® F127 at several concentrations. The effect of F127 on BCRP expression (mRNA and protein), mitochondrial transmembrane potential and cell hypodiploidy was assessed. Finally, the effect of this copolymer on cytotoxicity of doxorubicin in both hepatoma cell lines was investigated, as expressed by its reverse resistance index. KEY FINDINGS: It was demonstrated that F127 in both cell lines contributes to chemosensitization, as shown by BCRP down-regulation, an altered mitochondrial transmembrane potential and hypodiploidy and reverse resistance index values. A remarkable dependence of these effects significantly correlated with the copolymer concentration. CONCLUSIONS: These findings further uncover the potential usefulness of this copolymer as multidrug resistance reversal agent, increasing the efficacy of cancer therapies.