REGULATION OF KERATINOCYTE PROLIFERATION

1. In physiological situations the proliferation of epidermal cells (k eratinocytes) in the skin is a tightly controlled process. 2. However, in many common skin diseases, such as in psoriasis, the control mecha nisms go awry resulting in pathological epidermal hyperplasia (thicken ing).3. In those situations the keratinocytes enter the alternative pa thway of proliferation characterized by excessive growth rate, aberran t responses to growth factors, faulty differentiation, and increased m igratory capacity. 4. The participation of different growth factors in enhancing or inhibiting keratinocyte growth, both in physiological an d pathological conditions, has been reviewed. 5. The regulatory proces ses governing epidermal growth have relevance for the understanding of the mechanism of action of the drugs used in the treatment of skin di seases associated with epidermal hyperplasia. (C) 1998 Elsevier Scienc e Inc.