Cancer stem cells
Essentially, two models for tumour initiation and development have been opposed in recent years: the stochastic model and the hierarchical model. The stochastic model is based on the randomness of mutations, while the hierarchical model considers that a very small subpopulation of cancer cells is responsible for tumour initiation and development. These very few but very aggressive cells proliferate in the same way as stem cells and are therefore called cancer stem cells (CSCs).
When we consider, from a mathematical point of view, the consequences of these models, it is clear that the hierarchical model explains much more simply facts noted in oncology or in laboratory experiments such as the spontaneous extinction of tumours, the existence of a critical mass to initiate a “human” tumour in laboratory mice or the fact that a tumour, perfectly treated from a surgical point of view, can regenerate at the very place where it was treated, of course after several years.
The model we have proposed takes into account the competition of these cells with other differentiated cancer cells and healthy cells, a competition that is managed by many biochemical factors. Among other things, we have shown the particularly critical role of the plasticity of differentiated cancer cells, which can regain a strain character to maintain the dangerousness of the tumour. Finally, dynamic and spatial simulations show a certain accumulation of these CSCs at the edge of the tumor, in accordance with recent experiments.
Olmeda et M. Ben Amar, Clonal pattern dynamics in tumor: the concept of cancer stem cells, Scientific Reports 9:15607 (2019)
Physics and Mechanics of Soft Matter Laboratory: