The cardiotoxicity and myocyte damage caused by small molecule anticancer tyrosine kinase inhibitors is correlated with lack of target specificity

The use of the new anticancer tyrosine kinase inhibitors (TKI) has revolutionized the treatment of certain cancers. However, the use of some of these results in cardiotoxicity. Large-scale profiling data recently made available for the binding of 7 of the 9 FDA-approved tyrosine kinase inhibitors to a panel of 317 kinases has allowed us to correlate kinase inhibitor binding selectivity scores with TKI-induced damage to neonatal rat cardiac myocytes. The tyrosine kinase selectivity scores, but not the serine-threonine kinase scores, were highly correlated with the myocyte damaging effects of the TKIs. Additionally, we showed that damage to myocytes gave a good rank order correlation with clinical cardiotoxicity. Finally, strength of TKI binding to colony-stimulating factor 1 receptor (CSF1R) was highly correlated with myocyte damage, thus possibly implicating this kinase in contributing to TKI-induced cardiotoxicity.