LAUSR

Background/Aim: Multidrug resistance leads to therapeutic difficulties. There is great interest in experimental chemotherapy regarding multidrug resistance inhibitors and new anticancer agents. The aim of this study was to evaluate the anticancer activity of exocyclic sulfur and selenoorganic compounds on mouse T-lymphoma cell lines. Materials and Methods: A series of eighteen sulfur and selenium analogues of 2[1H]-pyrimidinone and hydantoin derivatives were evaluated towards their efflux modulating, cytotoxic and antiproliferative effects in mouse T-lymphoma cells. The combination assay with doxorubicin on multidrug resistant mouse T-lymphoma cells was performed in order to see the nature of drug interactions. Crystal structures were determined for two selected compounds with the highest efflux-modulating activity. Results: The sulfur analogues with aromatic rings almost perpendicular to pyrimidinethione ring at positions 1 and 6 showed the highest efflux inhibitory action, while all selenium analogues showed good antiproliferative and cytotoxic activities. Conclusion: The sulfur analogues can be modified towards improving their efflux inhibitory activity, whereas the selenium towards antiproliferative and cytotoxic activities.