Spatiotemporally Resolved Approach for Profiling Ferroptosis-Associated Metabolic Vulnerabilities in Tumors Using Mass Spectrometry Imaging and Stable Isotope Tracing

Ferroptosis, as an iron-dependent cell death mediated by lipid peroxidation, has sparked great interest in the tumor research community. Targeting ferroptosis has been proven to be a new therapeutic opportunity for inhibiting tumor growth. However, it is challenging to precisely characterize the metabolic pattern of ferroptosis in heterogeneous tumors and further identify ferroptosis-associated metabolic vulnerabilities for tumor treatment. In this work, we developed a spatiotemporally resolved method to image ferroptosis-associated metabolic alterations in 3D tumor spheroids by combining mass spectrometry imaging and stable isotope tracing techniques. The construction of a 3D tumor spheroid model allows for a more accurate simulation of ferroptosis, and the introduction of MALDI-MSI enables in situ screening of abnormal molecules in tumor tissues. Using this method, we showed that the expression proportion of