International Journal of Molecular Sciences Article Insight into Bortezomib Focusing on Its Efficacy against P-gp-Positive MDR Leukemia Cells Tomáš Kyca 1, Lucia Pavlíková 1,2, Viera Boháˇcová 1, Anton Mišák 3 , Alexandra Poturnayová 1, Albert Breier 1,4,* , Zdena Sulová 1,* and Mário Šereš 1,2,* 1 Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Dúbravská cesta 9, 84505 Bratislava, Slovakia;
[email protected] (T.K.);
[email protected] (L.P.);
[email protected] (V.B.);
[email protected] (A.P.) 2 Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, 84506 Bratislava, Slovakia 3 Institute for Clinical and Translational Research, Biomedical Research Center, Slovak Academy of Sciences, Dúbravská cesta 9, 84505 Bratislava, Slovakia;
[email protected] 4 Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 81237 Bratislava 1, Slovakia * Correspondence:
[email protected] (A.B.);
[email protected] (Z.S.);
[email protected] (M.Š.); Tel.: +421-2-593-25-514 or +421-918-674-514 (A.B.); +421-2-3229-5510 (Z.S.) Abstract: In this paper, we compared the effects of bortezomib on L1210 (S) cells with its effects on P-glycoprotein (P-gp)-positive variant S cells, which expressed P-gp either after selection with vincristine (R cells) or after transfection with a human gene encoding P-gp (T cells). Bortezomib induced the death-related effects in the S, R, and T cells at concentrations not exceeding 10 nM.