Overweight in mice, induced by perinatal programming, exacerbates doxorubicin and trastuzumab cardiotoxicity

Purpose: Trastuzumab (TRZ) is believed to potentiate doxorubicin (DOX) cardiotoxicity, resulting in left ventricular dysfunction. There is some evidence that overweight could influence anticancer drug-induced cardiotoxicity, though no study has evaluated the impact of moderate overweight, induced by postnatal nutritional programming, on the cardiotoxic effects of DOX alone or in combination with TRZ. Methods: Immediately after birth, litters of C57BL/6 mice were either maintained at 9 pups (normal litter, NL) or reduced to 3 (small litter, SL) in order to induce programming of ∼15 % overweight through postnatal overfeeding. At 4 months, NL and SL mice received a single intra-peritoneal injection of either saline, DOX (6 mg/kg), TRZ (10 mg/kg) or both (DOX-TRZ). Transthoracic echocardiography was performed 24 h before as well as 10 and 20 days after treatments. Results: Twenty days after DOX administration, systolic dysfunction was observed only in the overweight SL group, while NL mice group had a normal left ventricular ejection fraction. However, in the NL group, functional impairment appeared when TRZ was co-administered. Forty-eight hours after drug administration, gene expression of natriuretic peptides (ANP, BNP) appeared to be potentiated in DOX-TRZ mice of both the NL and SL group, whereas the expression of β-MHC increased significantly in overweight SL mice only. Conclusions: In an acute model of DOX cardiotoxicity, moderately overweight adult mice were more sensitive to cardiac systolic impairment. Moreover, our results confirm the potentiating action of TRZ on DOX-induced cardiotoxicity in lean mice.