Arecoline And Extracellular Calcium Ion Upregulate S100A7 MRNA Expression In Human Keratinocytes

Objective:To investigate the effect of arecoline and extracellular calcium levels on the growth and expression of S100A7 mRNA in human keratinocytes(HaCaT cells),and to further gain insight into the pathogenesis of OSF.Methods:The effect of a 24-hour exposure of HaCaT to arecoline of various concertrations on the growth was measured by MTT,and RT-PCR was used for detecting the expression of S100A7 mRNA in HaCaT after arecoline treament for 24 hours and elevated extracellular calcium levels.Results:(1)Arecoline at high concertrations(80-320μg/ml)inhibits the growth of HaCaT(P＜0.05).A exposure of HaCaT to 80,160 and 320μg/ml arecoline resulted in 11%,16%and 39%cell death,respectively. Arecoline at concertrations below 40μg/ml lacked both cytotoxicity to HaCaT and promoting effect on growth ofHaCaT(P＞0.05).A 24-hours exposure to Arecoline at high concertrations lead to marked morphous changes of HaCaT.(2)Exposure of HaCaT to Arecoline at concertrations of 40-80μg/ml slightly elevated S100A7 mRNA expression.An hour exposure of HaCaT to 1.0mM extracellular calcium ion can not elevate S100A7 mRNA expression,while a 48-hour exposure to 1.8 mM extracellular calcium ion coud elevated S100A7 mRNA expression(P＜0.05)Conclusions:(1)Arecoline at low concertrations is neither suppressive nor promotive to the growth of HaCaT,while arecoline at high concertrations inhibited the growth of HaCaT.Arecoline is cytotoxic to HaCaT.(2)Arecoline at certain concertrations upregulates S100A7 mRNA expression in HaCaT.The S100A7 gene and its encoding protein may play an important role in the pathogenesis of OSF.(3)Exposure to high extracellular calcium levels for a long time upregulates S100A7 mRNA expression in HaCaT.The calcium contained in betel quid may be involved in the pathogenesis of OSF.