Fig. 7: Collective dynamics of oncostreams increase cell spreading within the tumor core.

A Experimental setup: NPA-GFP glioma cells implantation and explant slice cultures generation for confocal time-lapse imaging. (Created in BioRender.com). B Single representative time-lapse confocal image of glioma cells within the tumor core (Movie #1). Tumor cells are GFP+ (green). C Tracking analysis of individual cell paths performed using the Track-Mate. D Preferred directions of cells within three zones (A–C) superimposed onto a representative time lapse-image. E Speed distribution and mean speed (µm/h) in Zones A, B, and C. F Distribution of angle velocity (θ) for each zone. The plot shows the proportion of cells moving in angle direction θ for each zone. G, H Classification of collective motion patterns: stream (two peaks = 2 preferred angle velocity), flock (only one peak) or swarm (no preferred angle velocity). G Angle Velocity was transformed to a histogram; these data were then used to calculate the likelihood that corresponds to either a stream, flock, or swarm. The results are given in (H) for each zone. The frequency distribution of the data (shown in black) uses a non-parametric estimation (kernel density estimator). We tested three types of distributions, ρ, to describe the dataset and give a likelihood for each case. The best fit was then determined by the Akaike weight (AW). I Co-implantation of highly malignant GL26-citrine cells (green) and human MSP-12 glioma cells (ratio 1:30), and MSP-12 cells alone (control – left image). Immunohistochemistry of human nuclei (black) denotes MSP-12 cells. Arrows show the distribution of MSP-12 cells. Scale bar: 100 μm. J Quantification of the distance of MSP-12 from the site of implantation. Biologically independent tumors, n = 3 for control and n = 5 (MSP-12 + GL26). Error bars ± SEM; Mann–Whitney two-sided t-test, *p = 0.0357. K Immunofluorescence images of human-nestin (red) labeling MSP-12 cells, and GL26-citrine cells. Experiment was performed in three independent tumor samples. Scale bar: 47.62 μm. L Angle histogram plots quantify the alignment of MSP-12 within oncostreams, and the random alignment of MSP-12 cells when implanted alone (with dashed overlays of the other condition’s alignment).