Fig. 10: Oncostreams are COL1A1-rich multicellular dynamic mesenchymal structures that regulate glioma migration and malignant behavior.

Summary representation of mesenchymal dynamic fascicles (oncostreams) present in high grade gliomas. Our study reveals that oncostreams display directional collective motility patterns including streams and flocks. Non-directional collective motion (swarms) are represented by round cells that move without a preferred direction of motion. Directional dynamic patterns function as tumoral highways to facilitate the intra-tumoral spread of cells and potentially participate in the local invasion of normal brain. Red shows patterns of migration within the tumor core, and blue marks the patterns at the tumor invasive border. Oncostreams are areas of mesenchymal transformation defined by a molecular signature enriched in COL1A1. COL1A1 knockdown disrupts oncostream organization, decreases intratumoral heterogeneity, and significantly increases animal survival. Our study reveals that oncostreams are anatomically and molecularly distinctive, are areas of mesenchymal transformation organized through interactions with the COL1A1 matrix, move by collective motion, and regulate glioma aggressiveness. Figure was created by the authors.