Spatial heterogenity of the mechanics of solid tumors*

In solid tumors tissue that is stiffer than healthy tissue is formed by cells that are softer than healthy cells. We try to address this contradiction by spatially resolved investigation of the mechanics of solid tumors tissues. We are able to measure the elasticity of slices of solid tumors on the millimeter scale with micrometer spatial resolution by AFM. This avoids measuring only heavily selected regions or only single cells extracted from dissected tissue. At the same time we are able to precisely align our AFM data with immunohistological stains. We can correlate the spatial heterogeneity of the elasticity maps with the distribution of cytokeratin. We complete these measurements with elasticity data on the whole tissue scale obtained by magnetic resonance elastography and single cell data from optical stretcher measurements. Each set of measurements is performed with tissue and from the same tumor, minimizing the error through biological variance within a dataset. Through the combination of the measurements we are able to bridge the scales from single cells to tissue level, to see how the individual cells contribute to the whole.