Phasor-FLIM Quantification of Changes in Keratinocyte Metabolism and Tissue Architecture in a Longitudinal Study of UV-induced Skin Cancer

Abstract

Two of the recognized hallmarks of cancer include fundamental shifts in energy metabolism toward a glycolytic phenotype and a reorganization of tissue architecture to enable tumor cell invasion and metastasis. Phasor-FLIM imaging of NAD(P)H and flavoproteins enables a rapid assessment of changes in metabolism, while fluorescence and scattering from structural proteins reveal changes in tissue architecture. Here, we demonstrate the practicality of conducting a long-term longitudinal study, monitoring the development and progression of UV-induced skin cancer in SKH1 mice. Linear Mixed Model Analysis of the entire dataset of more than 2000 repeated observations reveals statistically significant changes in bound NADH fraction as well as the degree of collagen fluorescence. Recent developments, including modifications to the instrument design to include a three-color, macro-fluorescence imaging mode to guide the selection of suspect regions will be discussed. This publication was made possible by grants from the National Institute for General Medical Science (NIGMS) (5P20GM103427), a component of the National Institutes of Health (NIH), and its contents are the sole responsibility of the authors and do not necessarily represent the official views of NIGMS or NIH.