Mass Spectrometry-Based Applications of Spheroids in Cancer Biology.

The use of cell culture techniques to model human disease is an indispensable tool that has helped improve the health and well-being of the world. Monolayer cultures have most often been used for biomedical research, although not accurately recapitulating an in vivo human tumor. Tumor spheroids are a form of three-dimensional cell culture that better mimics an avascularized human tumor through their cell-cell contacts in all directions, development of various chemical gradients, and distinct populations of cells found within the spheroid. In this review, we highlight how mass spectrometry has propelled the utility of the spheroid model to understand cancer biology. We discuss how mass spectrometry imaging can be utilized to determine the penetration efficiency of various chemotherapeutics, how proteomics can be used to understand the biology in the various layers of a spheroid, and how metabolomics and lipidomics are used to elucidate how various spheroids behave toward chemotherapeutics.