[Growth features of CHO cells in culture]

Dependence of growth characteristics of cell population and the monolayer formation on the initial plating concentrations of cells were studied on the established CHO cell line. The cells were cultivated under standard conditions on plastic substrate. Initial plating concentration was varied as: 1000, 2000, 3000, 4000, 5000, and 6000 cell/cm2. It was shown that growth of the cell culture can be formally described by standard S-shaped dependence. However, a more detailed analysis revealed a discrepancy between the experimental and expected data. Specifically the arrest of cell growth at the monolayer formation does not coincide with the time when the theoretical curves approach plateau. It has been concluded that cell proliferation and the formation of a monolayer are independent processes (at last in CHO cells). Both processes may be considered as analogues of proliferation and morphogenesis in metazoan. In addition, it has been shown that the arrest of cell division occurs not only by contact inhibition of proliferation during monolayer formation but also by reducing the size of cells to some limiting dimension and by increasing the polarization of cells.