Hyper-responsiveness of cancer stem cells to microenvironmental cues controls metastasis and therapy response through...

Cancer stem cells (CSCs) are key drivers of metastasis and therapy resistance but have been challenging to visualize and study in situ . Using a fluorescent CSC reporter, we observed very different population dynamics for CSCs and nonCSCs during metastatic lung colonization in breast cancer models. CSC expansive self-renewal drives early lesion formation before switching to a maintenance mode of balanced self-renewal and differentiation, whereupon nonCSC proliferation takes over as the main driver of metastatic expansion. Mechanistic analyses showed that CSCs are hyper-responsive to microenvironmental cues such as cell crowding and nutrient availability, suggesting a novel role for CSCs as sensors and early responders to fluctuating local conditions in the tumor. Incoming signals converge on YAP/TAZ/TEAD, with heightened CSC sensitivity and response supported by elevated receptor expression and increased chromatin accessibility around enhancers with TEAD binding sites. Targeting inputs to the YAP/TAZ/TEAD node reversed chemotherapy-induced enrichment of CSCs in lung metastases.

Different population dynamics for breast cancer stem cells (CSCs) and their differentiated progeny in early metastatic colonizationCSCs are hyper-responsive to microenvironmental cues and serve as sensors of local conditions for the tumorMany microenvironmental inputs converge on YAP/TAZ to regulate self-renewal vs differentiation fate decisions in the CSCTargeting YAP/TAZ input pathways blocks chemotherapy-induced enrichment of CSCs.