Commonly, we think of cancer as anarchy, a leaderless mob of deranged cells, storming through the body.
Pedro Lowenstein, Sebastien Motsch, and colleagues at the University of Michigan and University of Arizona think that cancer is highly organised--self-organised.
In brain cancer, the Michigan and Arizona researchers report that glioma cells build tumours by self-organising into streams, 10-20 cells wide, that obey a mathematically predicted pattern for autonomous agents flowing together.
These streams drag along slower gliomas, may block entry of immune cells, and swirl around a central axis containing glioma stem cells that feed the tumour's growth.
Lowenstein and Motsch mapped out this dynamic picture of glioma self-organisation by building and comparing two model systems, one biological and one mathematical.
The living model system was built in vivo using mouse and human glioma cells genetically tailored to express a deadly package of genes known to spur development and progression of brain tumours.
The observed movement, distribution, and invasive nature of the resulting streams of elliptically shaped glioma cells were predicted by their mathematical model, they report.
Assuming that the glioma cells were independent agents, the mathematical model took into account adhesion and repulsion dynamics between tumour cells.
The results showed unmistakable signs of non-random, self-organisation of brain tumours, say Lowenstein and Motsch.
Most striking, the presence of self-organising structures was not related to any specific cancer mutation.
These swirls eddied around cores of glioma stem cells that Lowenstein and Motsch describe as possible nucleating centers for brain tumour growth.
The in vivo model also produced glioma cells organised as individual spheres, including some that slipped out of the tumour and set themselves adrift in the cerebrospinal fluid that surrounds the brain's ventricles, and may mediate tumour dispersion throughout the brain.
All this evident self-organisation opens an exciting novel insight into brain cancer, say Lowenstein and Motsch, and makes disrupting tumour self-organisation itself a new target for brain cancer treatment.