Effects of Rhenium(I)-diselenoether and of its Diselenide Ligand on the Production of Cathepsins B and S by MDA-MB231 Breast Malignant Cells.

BACKGROUND/AIM: Rhenium(I)-diselenoether (Re-diSe) is a drug under development for the treatment of metastatic cancers, with selective inhibitory effects on MDA-MB231 cancer cells compared to normal HEK-293 cells, and with greater effects than its diselenide (di-Se) ligand. Rhenium (Re) compounds inhibit cathepsins, which are important proteolytic enzymes in cancer. This study investigated the effects of Re-diSe and di-Se on the production of cathepsins B and S in MDA-MB231 malignant and HEK-293 normal cells and their inhibitory effects following treatment with different doses for 72 h. MATERIALS AND METHODS: Elisa tests were used to assay the amount of cathepsins B and S in the medium of cultures. RESULTS: Re-diSe, but not diSe affected the viability of malignant cells and the expression of cathepsins B and S. CONCLUSION: To the best of our knowledge, this is the first demonstration that Re-diSe may decrease the production of cathepsins B and S in cancer cells at doses as low as 10 µM.

DNA profiling and in vitro cytotoxicity studies of tetrazolo[1,5-a]pyrimidine-based copper(II) complexes.

A series of N-benzoylated mononuclear copper(II) complexes of the type [Cu(L1-6)Cl2] (1-6), where L1= ethyl 4-benzoyl-5-methyl-7-aryl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate, L2= ethyl 4-(4-nitrobenzoyl)-5-methyl-7-aryl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate, L3 = ethyl 4-benzoyl-5-methyl-7-(4-methoxyphenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate, L4 = ethyl 4-(4-nitrobenzoyl)-5-methyl-7-(4-methoxyphenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate, L5 = ethyl 4-benzoyl-5-methyl-7-(4-chlorophenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate and L6 = ethyl 4-(4-nitrobenzoyl)-5-methyl-7-(4-chlorophenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate have been synthesized and characterized by spectral methods. Electron paramagnetic resonance spectra of complexes show four lines, characteristic of square planar geometry. The binding studies of the complexes with calf thymus DNA (CT-DNA) revealed groove mode of binding, which were further supported by molecular docking studies. Gel electrophoresis experiments demonstrated the ability of the complexes to cleave plasmid DNA in the absence of activators. Further, the cytotoxicity activity of the complexes were examined on three cancerous cell lines (lung (A549), cervical (HeLa) and colon (HCT-15)), and on two normal cells (human embryonic kidney (HEK) and peripheral blood mononuclear cells (PBMC)) by MTT assay.