Polyamine contents of human breast cancer cells treated with the cytotoxic agents chlorpheniramine and dehydrodidemnin B.

The cytotoxic agents chlorpheniramine and dehydrodidemnin B decreased the cell growth of estrogen receptor-negative human breast cancer cells MDA-MB231 and estrogen receptor-positive MCF-7, after 48 h treatment. Both agents reduced ornithine decarboxylase activity, but polyamine levels were increased in MDA-MB231 cells treated with dehydrodidemnin B. MCF-7 cells when treated with dehydrodidemnin B showed significant increases in spermidine and spermine contents. The results suggest that besides other effects, the cytotoxicity of DDB could be explained in part by the over-accumulation of spermidine and spermine.