Metabolic Response to Stress Differentiates Heterogeneous Cancer Cells with Varying Metastatic Potential

Intratumoral heterogeneity is ubiquitously present within primary tumors and contributes to intractable behaviors such as metastasis and mutability spatiotemporally. Mounting evidence has shown that heterogeneous cell populations can adversely affect cell metabolism and metastatic potential. The cell’s only fluorescent molecules within the electron transport chain, flavin adenine dinucleotide (FAD) and nicotinamide adenine dinucleotide (NADH), can allow the quantitation of cell metabolism. We demonstrate the use of the optical redox ratio (FAD/(NADH+FAD)) to determine the metabolic behaviors of a heterogeneous panel of cells with varying metastatic programs at normal conditions and following acute hypoxia. At normal conditions, we reveal an attenuation in the optical redox ratio as metastatic potential decreases, not including the non-metastatic cell line. We reveal that reoxygenating the clonogenic cells after hypoxia enabled further differences in the optical redox ratio for the highly metastatic (increased by 43 ± 9%), semi-metastatic (increased by 33 ± 4%), and non-metastatic (decreased by 14 ± 7%) cell lines. This work coalesces two potential strategies for cancer treatment: 1) the optical redox ratio to assess cell metabolic features and therapy-induced changes 2) the method of inducing a “stress” test to identify further differences in heterogeneous cell populations