Poly-D-lysine enhances the genotoxicity of bleomycin in cultured CHO cells.

Cultured CHO cells were treated with the radiomimetic antitumor agent bleomycin (BLM) and post-treated with the polycationic compound poly-D-lysine (PDL), recently reported by us as able to potentiate chromosome damage induced by X-rays and chemical mutagens in both plant and mammalian cells. Our results seem to indicate that PDL enhances the genotoxic action of BLM measured as induced chromosomal aberrations, colony-forming ability and DNA strand breakage. Taking into account the reported low efficiency of BLM treatment due to problems with cellular uptake, enzymatic degradation and efficient repair, the possibility of optimizing the dose-effectiveness for cancer therapy is discussed.