Thermal preconditioning protects rat cardiac muscle cells from doxorubicin-induced apoptosis

Doxorubicin (DOX=adriamycine), an effective chemotherapeutic agents for can cers, has severe cardiotoxicity. In the paresent study, we examined the pro tective effect of thermal preconditioning (TP) against apoptosis of rat car diac muscle cells induced by DOX. Treatment with DOX (10 mu M) for 24 hrs r esulted in apoptosis of cardiac muscle cells, which was evaluated by examin ing "DNA ladder" formation and TUNEL staining. The number of TUNEL-positive cells was significantly decreased in cells subjected to TP by incubation a t 42 degrees C for 30 min, 24 hrs prior to DOX-treatment. Antisense oligonu cleotides of the heat shock protein (HSP) 70 blunted this effect. These res ults indicate that DOX-induced apoptosis in cardiac muscle cells is prevent ed by TP, at least in part, via a HSP70-mediated mechanism.