Identification of cancer chemosensitivity by ODE and GMM modeling of heterogeneous cellular response to perturbations in fluorescent sphingolipid metabolism

Cancer refers to a group of diseases in which cells display uncontrolled growth. Chemotherapy options are usually conditioned by generating resistance which is explained in part by the intrinsic heterogeneity of the population in the tumor. Because the study of resistance requires biosensors able to report the response at the single cell level, we propose to use fluorescently labeled SL to estimate pathway dynamics at the single cell level and investigate its possible application as gemcitabine (GMZ) response sensor in pancreatic cancer by comparing the dynamics between GMZ resistant (Panc-1, MiaPaca-2) and sensitive (BxPC3) cell lines. We used imaging flow cytometry to extract multiple image features and classify cells using gaussian-mixture model (GMM) to generate response fingerprints upon known perturbations. The results suggest that GMZ inhibits the Sphingomyelin-Synthase of BxPC3. Also, we constructed and fitted a dynamical mathematical model to simulate these perturbations and formulate cell line models revealing a striking heterogeneity among them. Predictions of the model respect the effect of GMZ in the accumulation of ceramide in BxPC3 and glucosyl-ceramide in MiaPaca-4 were confirm experimentally. Altogether, these results indicate that fluorescent-SL analogues can be used as sensors of chemotherapy in pancreatic cancer and reveal pathway dynamics between different cell lines, and its potential usage for the development of in vitro chemosensitivy assays able to dissect pathway dynamics to overcome resistance.