DIFFERENT GROWTH-PATTERNS OF A CANCER CELL-POPULATION AS A FUNCTION OF ITS STARTING GROWTH-CHARACTERISTICS - ANALYSIS BY MATHEMATICAL-MODELING

The growth kinetics of a cancer cell population as a function of the t otal number of cells and the proportion of proliferating and resting c ells at the beginning of the growth has been analysed by a mathematica l model. The model takes into account the processes of cell division, death and transition from proliferation to rest and backwards. It is s hown that a single cell population growing under the same environmenta l conditions has an extremely broad spectrum of growth patterns. The w hole multiplicity of possible growth patterns has been determined by t he inherent cellular growth characteristics of the population, while t he growth pattern actually realized of the variety of growth curves de pends on the total number of cells and the proportion of proliferating and resting cells at the initial moment of growth. The model is shown to provide a good prediction of experimentally measured kinetics of r egrowth of tumour cells subcultured after various times of the growth in unfed cultures, and the kinetics of tumour cell growth after severe hypoxia. The role of cell transitions between proliferating and resti ng stages in the problem of growth control is discussed.