A Novel Organometallic Rhenium Salt: DNA-Binding and Cytotoxicity Studies on Pancreatic, Breast and Lymphoma Cancers

Abstract DNA-binding studies of a variety of rhenium(I) tricarbonyl complexes are known. Primarily the rhenium complexes bind to DNA through intercalation or minor groove or both. We synthesized a novel organometallic salt of the type, [Re(µ-H)Re]+[Re(µ-OR)3Re]-. The UV-vis and emission spectroscopic titrations and viscosity studies indicate that the salt binds to DNA through partial intercalation. A variety of mono-, di-, and trinuclear rhenium(I) carbonyl complexes are known to exhibit cytotoxicity against numerous cancer cell lines. Examples of the cytotoxicity of tetranuclear rhenium (I) tricarbonyl complexes are rare. We have found that the tetranuclear, novel organometallic salt is highly potent on numerous cancer cells. The IC50 values (concentrations required to induce 50% cell deaths) are 0.220 µM on BxPC-3 pancreatic cancer cells, 0.298 µM on estrogen receptor positive MCF-7 breast cancer cells, 0.948 µM on triple negative MDA-MB-231 breast cancer cells, and 0.300 µM on U-937 lymphoma cells.