Inhibition of proliferation and cell-cycle progression of keratinocytes by DCE and CS.

<p>Proliferation of keratinocytes treated with DCE, CS or HCS either in presence or absence of IL-22 was proportional to crystal violet incorporation (A), which was measured with an ELISA reader after 2 d of culture. Data are expressed as fold induction of treated <i>vs.</i> untreated samples, which were given a value of 1. * <i>p</i>≤0.01 and ** <i>p</i>≤0.05. B) PCNA, cyclin D1, and pRB were analyzed by Western blotting. Graphs show densitometric values of PCNA, cyclin D1, and pRB staining on blots (D. U., Densitometric Units; F. I., Fold Induction). Western blots are representative of 3 independent experiments performed on 3 different keratinocyte strains obtained from biopsies of different healthy donors. * <i>p</i>≤0.01. C) Cell-cycle distribution analysis of cultured keratinocytes treated or not with DCE, CS, or HCS, for 16 h. The percentage of keratinocytes in G0-G1, S, and G2/M phases are indicated in each histograms.