Imatinib mesylate induces necroptotic cell death and impairs autophagic flux in human cardiac progenitor cells

The receptor tyrosine kinase inhibitor imatinib mesylate has improved patient cancer survival rates but has been linked to long-term cardiotoxicity. This study investigated the effects of imatinib on cell viability, apoptosis, autophagy and necroptosis in human cardiac progenitor cells in vitro. After 24 hours, imatinib significantly reduced cell viability (75.9{+/-}2.7% vs._100.0{+/-}0.0%, n=5, p0.05) increase in viability after imatinib and wortmannin co-treatment. Imatinib-induced necroptosis was associated with an 8.5{+/-}2.5-fold increase in activation of mixed lineage kinase domain-like pseudokinase. Imatinib-induced toxicity was rescued by RIP1 inhibition relative to the control; 88.6{+/-}3.0% vs. 100.0{+/-}0.0% (n=4, p>0.05). In summary, imatinib applied to human cardiac progenitor cells depolarizes mitochondria and induces cell death through necroptosis, which can be recovered by inhibition of RIP1, with an additional partial role for autophagy in the cell death pathway. These data provide two possible targets for co-therapies to address imatinib-induced long-term cardiotoxicity.