ABSTRACT
AIM: To investigate the multidrug resistance(MDR),reversal activity of 2-[4-(2-pyridin-2-yl-vinyl) henyl]-4,5-bis-(4-N,N-diethylaminophenyl)-1(H)-imidazole(FG020318) in a retinoblastoma subline SO-Rb50/VCR,which is resistant to vincristine.METHODS: The procedure of stepwise increase in drug concentrations was used to obtain SO-Rb50/VCR,which was resistant to 200 ?g/L vincristine. The chemosensitivity of this drug resistant cell line with and without FG020318 or cyclosporine A(CSA) were detected by MTT assay and the function of p-glycoprotein(P-gp) was examined by rhodamine 123 accumulation detected with flow cytometry(FCM).RESULTS: FG020318(2.5 ?mol/L) significantly reduced IC50 and increased the rhodamine accumulation in a concentration-dependent manner. It was much stronger than the positive control CSA in reversal of MDR.CONCLUSION: A new tumor MDR modulator FG020318 partly reverses MDR in SO-Rb50/VCR.It may be a promising new drug to tackling MDR.