Dynamics of tumoral cell proliferation

The dynamics of the growth of cell colonies and tumours has been characterised by means of scaling techniques, which allow for very accurate descriptions of cell contour variation as a function of time . Scaling techniques used to analyse the fractal nature of cell colonies growing in vitro, and that of tumours developing in vivo, showed them to exhibit exactly the same type of dynamics, irrespective of phenotype, genotype or malignant status. This dynamics corresponds to the Molecular Beam Epitaxy universality class, which implies a linear growth rate ( in strong contrast with the commonly assumed exponential - type growth ), a growing border , and interface cell migration. The main mechanism responsible for tumour progression, as for any cell proliferation process, seems to be surface cell diffusion on the tumour border.

This result has a number of important consequences concerning solid tumours .To begin with, the effectiveness of chemotherapy appears to be somehow dependent on the specific surface of tumours .A second implication is that the most malignant cells are always located at the tumour border . These remarks may have profound implications for a better understanding of the tumour kinetics, the progression of malignant phenotypes at different stages of development, and the host - tumour relationship.