In Situ Investigation of Intercellular Communication in Ferroptosis Integrated Scanning Electrochemical Microscopy with Microfluidic Devices

Ferroptosis has been recognized as a potential treatment for various cancers. Still, in the complex tumor microenvironment, the communication between cancer cells and tumor-associated macrophages (TAMs) plays a crucial role in tumorigenesis and progression. In this work, scanning electrochemical microscopy (SECM) has been combined with microfluidic devices to enable on-chip cell coculture and in situ investigation of the communication between triple-negative breast cancer cells (TNBCs) and TAMs in ferroptosis. In the coculture system, TNBCs and TAMs were used as responding cells and signaling cells, respectively. By in situ monitoring the changes of key parameters (ROS, glutathione (GSH), and cell membrane permeability) in Erastin-induced ferroptosis, it was found that TAMs partially restored the reduced GSH efflux, increased ROS release, and impaired cell membrane barrier in TNBCs, indicating that TAMs can suppress TNBC ferroptosis. Mechanistically, TNBCs could promote M2 macrophage polarization, and M2-TAMs achieved suppression of TNBCs ferroptosis through the STAT3-related signaling pathway. After inhibition of STAT3, increased ROS release and membrane permeability as well as decreased GSH efflux of TNBCs were in situ monitored by SECM, demonstrating the intercellular communication mechanism in ferroptosis. Therefore, this work provides a potential strategy of targeting TAMs for ferroptosis-based TNBC therapy.