Аннотация:AbstractBackground: Acquired resistance to various drugs is a key challenge for anticancer therapy.Earlier we have revealed a selective apoptosis of tumor cells induced by polyvalent cationicpeptides (CPs) both in vitro and in vivo by inactivation their cell targets – multifunctionalchaperone proteins nucleolin (NCL) and nucleophosmin (NPM). Here we applied Arg/Lys-enriched CPs as well as CPs, conjugated with Doxorubicin (Dox) to induce cell deathby nucleolar stress mechanisms both in Dox- sensitive breast cancer (BC) cells and inDox-resistant ones. Molecular interactions between CP as ligand and cellular targets usingcomputer modeling by docking have been done. Then, CP potential for anticancer therapyof various malignant tumors is discussed.Objective: An analysis of cell survival in breast cancer (BC) sublines that are sensitive orresistant to Doxorubicin (Dox) by cationic peptides (CPs) and conjugate CP +Dox.Results: The data indicate that Arg/Lys enriched CPs might be perspective agents forinducing BC cell apoptosis and for transport Dox or other drugs in tumor cells to overcomedrug resistance.Conclusion: Molecular docking is effective tool for modeling and evaluating of interactionsand competitive binding of CPs to their cellular targets. This approach is also useful fordesign novel peptides with high anticancer properties and low toxicity for patients.Keywords: breast cancer (BC) cell sublines, acquired resistance to Doxorubicin (Dox),chaperone proteins NC and NPM, cationic peptides (CPs), Dox-resistant BC cell apoptosis