Abstract: Objective To investigate the effects ofviaminate on the proliferation and differentiation of HaCaT cells,a human keratinocyte cell line.Methods Cultured HaCaT cells were treated with various concentrations (2,5,10,15,20,25 and 30μg/mL) of viaminate for various durations.The cell proliferation was assessed by MTT method,the changes of cell cycle and apoptosis rate by flow cytometry,the changes of keratin 10 and involucrin mRNA expressions by semi-quantitative reverse transcription PCR.Results The proliferation of HaCaT cells was inhibited by the treatment with viaminate of≥2μg/mL for 48 h,and the inhibition rate was raised with the increase of treatment time and dosage.The viaminate of 30μg/mL inhibited the proliferation of HaCaT cells by 57.67% and 82.00% at 48 and 72 h after the incubation respectively,and elevated the mRNA expression of involucrin from 40.80% to 156.12%,decreased the mRNA expression of keratin 10 from 96.46% to 14.60%.The mRNA expression of involucrin increased with the elevation of viarninate dosage.Under the treatment with viaminate for 48 h,the cell population at G₁ phase significantly increased,that at S and G₂ phases decreased;the switching of G₁ to G₂ was inhibited;but the cell apoptosis was not affected.Conclusion Viaminate could inhibit the proliferation and induce the differentiation of keratinocytes.

Key words: Retinoids, Keratinocytes, Cell proliferation, Cell differentiation