Identification of a novel type of focal adhesion remodelling via FAK/FRNK replacement, and its contribution to cancer evolution

Abstract Numerous studies have investigated the various cellular responses against genotoxic stress, including those mediated by focal adhesions. Nevertheless, we here identified a novel type of focal adhesion remodelling that occurs under genotoxic stress conditions, which involves the replacement of active focal adhesion kinase (FAK) with FAK-related non-kinase (FRNK). FRNK stabilized focal adhesions, leading to strong cell-matrices adhesion, and FRNK-depleted cells were easily detached from the matrices upon genotoxic stress. This remodelling occurred in a wide variety of cells. In vivo, the stomachs of Frnk-knockout mice were severely damaged by genotoxic stress, highlighting the protective role of FRNK against genotoxic stress. FRNK was also found to play a vital role in cancer progression, because FRNK depletion significantly inhibited cancer dissemination and progression in a mouse cancer model. We hence conclude that this novel type of focal adhesion remodelling reinforces cell adhesion and acts against genotoxic stress, which results in the protection of normal tissues, but, in turn, facilitates cancer evolution.