Untargeted Metabolite Mapping in 3D Cell Culture Models using High Spectral Resolution FT-ICR Mass Spectrometry Imaging - Datasets

Mass spectrometry imaging (MSI) is an effective tool to investigate multicellular tumor spheroids (MTS) in a spatially-resolved manner. It has been used to study the distribution of lipids, post-translational modifications, metabolites and the time-dependent penetration of drugs. Using the high spectral resolution achievable with Fourier-transform ion cyclotron resonance (FT-ICR), here we use MSI to image 8-day-old MCF-7 spheroids. We show that specific metabolite markers (adenosine phosphates and glutathione) indicate that the central region of these cell culture models experience increased hypoxic and oxidative stress. By using discriminatory analysis, we have identified which m/z values localize towards the outer proliferative or central hypoxic regions of an MTS, and have assigned elemental formula with sub-ppm error. Using this information, we have mapped these metabolites back to distinct pathways to improve our understanding of the molecular environment of a tumor