Targeting Nucleotide Binding Domain of Multidrug Resistance-associated Protein-1 (MRP1) for the Reversal of Multi Drug Resistance in Cancer.

Multidrug resistance (MDR) is the major cause, by which cancer cells expel the drugs out, developing a challenge against the current chemotherapeutic drugs regime. This mechanism is attributed to the over expression of ABC transporters like MRP1 on the surface of cells. Since nucleotide binding domains (NBD) of ABC transporters are the site of ATP binding and hydrolysis, thereby in this study we have targeted NBD1 of MRP1using molecular docking and molecular dynamic simulations (MDS). The compounds present in the FDA approved library were docked against NBD1 of the human multidrug resistance associated protein 1 (PDB ID: 2CBZ). For the docking studies, Standard Precision and Extra Precision methods were employed. After the EP docking studies, ligands showed an extremely low docking score that was indicative of very high binding affinity of the ligands to the NBD. Apart from the low docking score, another short listing criterion in simulation studies was the interaction of incoming ligand with the desired conserved residues of NDB involved in ATP binding and hydrolysis. Based on these measures, potassium citrate (DB09125) and technetium Tc-99m medronate (DB09138) were chosen and subjected to 100 ns simulation studies. From the MDS study we concluded that between these two compounds, potassium citrate is a better candidate for targeting MRP1.