Sensitivity to the microenvironment is an important characteristic of tumours. The stiffness of the extracellular matrix can influence cellular transformation and invasion. Although this is established for certain types of tumour, the impact of stiffness response for oral squamous cell carcinoma (OSCC) is not understood. In their Research Article, Adam Engler, Marcelo Lamers and colleagues (Matte et al., 2019) tested the response of OSCC cell lines to stiffness. They found that on stiff matrices, a highly invasive OSCC line had lowered adhesion strength and migrated faster than a less invasive OSCC line. Importantly, when these less invasive OSCC cells were cultivated on a stiff substrate, they increased migration speed and expressed markers specific to mesenchymal cells. Interestingly, the authors further used tumour sections from OSCC patients to investigate matrix stiffness around the tumour, with collagen organisation as a readout for rigidity. They found that in tissues of an advanced disease state and from patients with shorter recurrence-free survival time, the stiffness of the matrix was increased. Taken together, these data suggest that OSCC cells can be mechanically conditioned, and sensitivity to matrix stiffness, at least in part, mediates tumour progression.
