Characterization of heterogeneous response to chemotherapy by perturbation-based modeling of fluorescent sphingolipid metabolism in cancer cell subpopulations

Abstract

Cancer treatments options are limited by the generation of therapy resistance, which is due by intratumoral heterogeneity in cell response. The study of resistance requires biosensors able to report the response at the single cell level. We suggest that changes in the distribution and dynamics of a fluorescent sphingolipid probe (SL) could help to deconvolve cancer heterogeneity. We used imaging flow cytometry to extract multiple image features and classify cells into subpopulations across multiple perturbations using Gaussian Mixture Models. This enabled us to model the sphingolipid metabolism in cancer cell subpopulations. The results showed that a chemosensitive cell line of pancreatic cancer has in fact a highly resistant subpopulation. Resistant cancer cell lines harbor also subpopulations insensitive to chemotherapy whereas others adapt to the perturbation induced by the drug. This suggests that fluorescent-sphingolipid analogs are promising sensors of chemotherapy response for the development of in vitro chemosensitivity assays able to disentangle cancer heterogeneity.