Assessing endothelial cytotoxicity induced by tyrosine kinase inhibitors: insights from Raman and fluorescence...

Since their approval, tyrosine kinase inhibitors (TKIs) have been widely used in antitumor therapy for chronic myeloblastic leukemia. Despite being approved by the FDA in 2001 to treat a rare cancer called chronic myeloid leukemia (CML), imatinib and other TKIs remain subjects of research for several reasons, such as their long-term effects, resistance, or molecular mechanisms. This study uses Raman and fluorescence imaging to investigate the in vitro cytotoxic effects of two TKIs, imatinib and dasatinib, on human aortic endothelial cells (HAECs). A comprehensive range of concentrations for these TKIs was applied to assess their cytotoxic impact based on viability, inflammation, and biochemical profile. Detailed data analysis revealed alterations in the biochemical profiles of cellular components, even though the viability of HAECs was around 80-90%. These changes indicate that, despite the cells retaining viability, they are experiencing considerable sub-lethal stress. Specifically, cells exposed to clinically relevant TKI concentrations showed increased signals from proteins and saturated lipids alongside decreased signals from nucleic acids, cytochromes, and unsaturated lipids. The subcellular analysis highlighted prominent changes in the perinuclear area, dominated by the endoplasmic reticulum and the cytoplasm. These findings suggest that TKIs are cytotoxic to vascular endothelium at concentrations close to those that are clinically observed. The predominant mechanism appears to involve oxidative stress-mediated inflammation, as evidenced by increased lipid content in treated cells and ICAM-1 staining. This cytotoxicity may contribute to the cardiotoxic effects observed during TKI therapy.