Ezrin Functions as a Key Mechanosensitive Effector to Preserve Cell Structure and Promote Survival and Metastasis of Lung Cancer Cells during Circulation.

Metastasis remains the leading cause of cancer-related mortality, a process in which circulating tumor cells (CTCs) play a central but incompletely understood role. Although most CTCs are rapidly eliminated during circulation through detachment-induced anoikis and fluid shear stress (SS)-triggered apoptosis, a subset of CTCs can survive these hostile conditions; however, the underlying mechanisms remain poorly defined. To investigate this, we developed a microfluidic circulatory system that mimics physiological SS and performed transcriptomic profiling of A549 lung cancer cells under SS, attached, and static suspension conditions. Through this approach, we identified the ROS-CD44-Ezrin axis as a potential mechanosignaling module that may contribute to CTC survival under shear stress. In this cascade, SS-induced ROS and CD44 converge to activate Ezrin via phosphorylation at Thr567. Once activated, Ezrin appears to coordinate its two canonical functions-membrane-cytoskeleton reinforcement and pro-survival signaling via PI3K/AKT/Bcl-2 and NF-κB/p38/JNK pathways-within this specific mechanobiological context to preserve cell integrity and limit apoptosis. Our findings suggest that these well-established molecular functions are differentially engaged under shear stress, revealing a context-dependent survival mechanism that may offer opportunities for therapeutic exploration, pending further validation in more clinically relevant models.