Enhanced cytotoxicity caused by increased DNA strand breakage resulting from synergistic potentiation of bleomycin with Bacillus thuringiensis subsp. israelensis delta-endotoxin.

We previously reported that a 25 kDa Bacillus thuringiensis subsp. israelensis (BTI) delta-endotoxin potentiates the cytotoxicity of bleomycin (BLM) in cultured cells. In order to clarify the mechanism involved, we examined the induction of DNA strand breakage by BLM in the presence of BTI toxin. Results showed that the increase in strand breakage resulted in enhanced cytotoxicity through the synergistic potentiation of BLM with BTI toxin.