Mechanics and cancer
Studies of the role of actin in tumour progression have highlighted its key contribution in cell softening associated with cell invasion. In a collaborative project, the labs of Florence Janody (IGC) and Joana Paredes (i3S) demonstrated that cells from a human breast cell line with conditional Src induction undergo a stiffening state prior to acquiring malignant features. This state is characterized by the transient accumulation of stress fibres and upregulation of Ena/VASP-like (EVL). EVL, in turn, organizes stress fibres leading to transient cell stiffening, ERK-dependent cell proliferation, as well as enhancement of Src activation and progression towards a fully transformed state. The team also found that EVL accumulates predominantly in premalignant breast lesions and is required for Src-induced epithelial overgrowth in Drosophila. While cell softening allows for cancer cell invasion, this work reveals that stress fibre-mediated cell stiffening could drive tumour growth during premalignant stages. The authors propose that a careful consideration of the mechanical properties of tumour cells could therefore offer new avenues of exploration when designing cancer-targeting therapies. The paper by Tavares et al. entitled “Actin stress fiber organization promotes cell stiffening and proliferation of pre-invasive breast cancer cells” was published in Nature Communications.