Cytotoxicity of rhenium(I) alkoxo and hydroxo carbonyl complexes in murineand human tumor cells

The rhenium(I) alkoxo/hydroxo carbonyl complexes were shown to be very pote nt in suspended tumor cell lines in suppressing growth but were more select ive in inhibiting the growth of cultures from solid tumors. Their mode of a ction in L1210 lymphoid leukemia cells indicated that they were not alkylat ing agents but interfered with nucleic acid metabolism at multiple enzyme s ites, e.g, dihydrofolate reductase, PRPP-amido transferase, thymidine kinas e, with DNA strand scission after 60 min incubation. These compounds did no t function mechanistically exclusively as cisplatin derivatives causing int rastrand linkages of DNA but rather they mimicked the metal complexes of am inecarboxyboranes, furan oximes, N-substituted thiosemicarbazones, trifluor omethyl borons and ferratricarbadecarbanyl complexes acting as antimetaboli tes.