Journal: bioRxiv
Article Title: Pressure drives rapid burst-like collective migration from 3D cancer aggregates
doi: 10.1101/2021.04.25.441311
Figure Lengend Snippet: a) Schematic representation of aggregate preparation and imaging process. b) Over 12 h, aggregates in 0.5 mg ml − 1 collagen (LCC; top) burst into the matrix, whereas aggregates embedded in 2.5 mg ml − 1 collagen (HCC; bottom) did not. Nuclei tracks at 12 h from each condition are shown, scale bars = 50 µ m. c) Comparison of average absolute cell velocities ⟨ V t ⟩ within aggregates embedded in LCC & HCC at different time points (N = 10 each, standard error of the mean (s.e.m.)). d) Average MSD for three time windows (N = 10 each). Inset shows the MSD in log scale between 4-8 h for LCC and HCC, with their corresponding slopes (s.e.m.). e) Zoomed-in view of the bursts (red box) and non-invasive (blue box) regions from (b) (scale bars = 20 µ m). f) Averages of diffusivity (D) and powerlaw exponent α obtained by fitting f(x) = α x + 6 D onto the log of window MSDs (N = 10 each, s.e.m.). g) Representation of both the early random and later collective migration as observed in LCC. h) Velocity correlation ⟨C⟩ binned over distances (N = 10, bin size = 20 µ m). Exponential decay function fit on distances up to 150 µ m at 8 h (inset). i) Mean velocity correlation length acquired over time (median smoothed, N = 10, s.e.m.). j) Contractile stresses exerted by aggregates in LCC and HCC on their ECM (N =5 each, s.e.m.). k) Mean Voronoi volume of cells within aggregate acquired over time (N = 10, s.e.m.).
Article Snippet: Based on tracked nuclei positions, a MATLAB function ‘N-D Voronoi diagram’ was applied to retrieve an estimate for the cell borders.
Techniques: Imaging, Comparison, Migration