Cell-state specific drug-responses are associated with differences in signaling network wiring

Yet, even isogenic cells in an homogenous environment show heterogeneity in their intracellular “cell-state”, as well as their response to extracellular signals. Here, we aimed to better understand this relation between these phenomena by investigating how information flows through the EGF-receptor centered network upon targeted drug treatment, and how this is affected by cell-to-cell-state differences.

Using single-cell ID-seq, we profiled the cell-state and signaling activity of primary human epidermal stem cells by measuring 69 (phospho-)proteins upon inhibition of the Erk/MAPK (p90RSK) and Akt/mTOR (p70S6K) routes downstream of the EGF pathway. We found that the effects of drug treatment propagated from the EGF-signalling pathway to other connected parts of the cellular signaling network, indicating altered signaling flow.