Lapatinib Induces Ferroptosis in Cardiomyocytes by Regulating ATF4/GPX4.

The TKI-targeted agent lapatinib has been applied in clinical oncology for the management of multiple malignancies. Nonetheless, its therapeutic benefit is restricted by cardiotoxic effects that endanger patient survival, and the underlying molecular basis remains unclear. The GSE146096 dataset containing transcriptomic profiles of lapatinib-exposed human cardiomyocytes was analyzed to identify ferroptosis-related differentially expressed genes (DEGs). Protein expression of selected targets was subsequently confirmed by Western Blot. Reactive oxygen species (ROS) accumulation, Fe²⁺ levels, and mitochondrial membrane potential in AC16 cells exposed to lapatinib were examined using confocal microscopy. A microplate reader was employed to quantify alterations in malondialdehyde (MDA) and glutathione (GSH) levels in cardiomyocytes. Eight ferroptosis-associated genes were identified in lapatinib-treated cardiomyocytes, including the canonical regulator GPX4. siRNA interference and Western Blot analyses demonstrated marked induction of ATF4 expression and significant suppression of GPX4 expression following lapatinib exposure in AC16 cells. CCK-8 assays indicated dose-dependent cytotoxicity. Confocal microscopy and transmission electron microscopy (TEM) revealed altered mitochondrial morphology accompanied by a reduction in mitochondrial membrane potential. Intracellular MDA levels increased substantially, whereas GSH levels declined, indicating lipid peroxidation and subsequent ferroptosis. Treatment with the ferroptosis inhibitor Ferrostatin-1 (Fer-1) or silencing of ATF4 expression effectively attenuated lapatinib-induced cytotoxicity. Lapatinib enhances ATF4 expression in cardiomyocytes, suppresses GPX4, triggers lipid peroxidation, induces ferroptosis, and thereby contributes to cardiotoxicity.