The anthracycline anticancer agent doxorubicin functions primarily as a topoisomerase-II poison, but forms more cytotoxic DNA adducts in the presence of formaldehyde. Doxazolidine is a doxorubicin-formaldehyde conjugate that directly forms DNA adducts and as such is a suitable model compound to study cellular responses to doxorubicin-DNA adducts. While doxorubicin-DNA adduct-forming treatments have been shown to be highly cytotoxic both in vitro and in vivo, the overexpression of Bcl-2 in cancer cells may limit the therapeutic potential of such treatments. Bcl-2 overexpressing HL-60 cells (HL-60/Bcl2) are resistant to short-term doxazolidine treatment (<12 hr), however, over longer treatment times this resistance was overcome. Cell death occurred via classical apoptosis indicating the involvement of Bcl-2 family members in the mechanism responsible for overcoming resistance. The expression of pro-apoptotic Bim-L increased as did the interaction between Bim-L and Bcl-2 in response to doxazolidine treatment over time, indicating that these changes may be responsible for driving the cells to undergo apoptosis. These findings suggest that the DNA damage induced by doxazolidine and potentially other anthracycline-DNA adduct-forming treatments may be sufficient to induce apoptosis in Bcl-2 overexpressing cancer cells, thus providing a major clinical advantage.