[Cell cycle time of normal epidermis, psoriasis and some epidermal tumors (author's transl)].

Cell kinetic of human epidermis has been studied with different techniques of labeling by 3H-thymidine. A review of the literature for human epidermis, psoriasis and some epidermal tumors has been performed and discussed in the light of our own studies. If the cell cycle time seems to be slightly shorter in epidermal tumors in comparison to normal epidermis, this doesn't constitute the fundamental characteristic of the neoplastic lesions. Indeed the most specific alteration in the cell cycle parameters for precancerous and cancerous tissue is a lengthening of the S phase duration. This modification of the DNA synthesis time is perhaps of reflection of the depressed state of the chromatin of neoplastic tissues.