Abstract
The composition and dynamic properties of the plasma membrane are believed to play a central role in the regulation of cellular proliferation and differentiation. In particular, lipid composition seems to be an important factor for the dynamic properties of the plasma membrane. Cultured keratinocytes provide a useful model system for studying epidermal differentiation, because the differentiation capacity of cells is dependent upon the external calcium concentration. Recently, we have utilized this system for the study of differentiation-linked changes in lipid metabolism.
On the other hand, it has been reported that several growth factors play important roles for proliferation and differentiation in normal and transformed cells. Thus it is surmised that lipid metabolism changes during differentiation to attain a steady state where various kinds of lipids exist in dynamic equilibrium and growth factors may modify the equilibrium. It is therefore interesting to study how the changes: s occur in the process of malignant transformation, and to clarify the possible relation between change of lipid metabolism and malignant transformation.
Since lipid synthesis is dependent upon the presence of external lipoprotein, we have studied lipid metabolism of normal epithelial cells and cancer cells in serum-free culture to evaluate an intrinsic lipid metabolism in the cell. Furthermore, we have studied effects of epidermal growth factor (EGF) and acidic fibroblast growth factor (aFGF) on the lipid metabolism of the cell in a serum-free culture.
