ABSTRACT
Objective To investigate the effect of serum-deprivation on the changes of [ Ca2+ ] i and the protein release of S100A13 and fibroblast growth factor 1 ( FGF-1 ) in thyroid cancer TT cell,and to reveal the role of Ca2+in the protein release of S100Al3 and FGF-1.Methods The protein expressions of FGF-1 and S100A13 in TT cells under serum-deprivation were detected by Western blot.The released FGF-1 protein from TT cells in the supernatant fluid was detected by ELISA.Realtime dynamic examinations on the change of 1 h [ Ca2+ ] i in TT cells under serum-deprivation were detected by confocal laser scanning microscopy.Then,the effect of EGTA( 2.5 mmol/ L),BAPTA-AM (2.5 μmol/L)on distributions of the fluorescence of S100AI 3 and FGF-1 in TT cells under serumdeprivation for6 h were detected by indirect immunofluorescence.Results The expressions of FGF-1 and S100A13 in TT cells after serum-deprivation for4 h and 6 h were reduced( P＜0.05 or P＜0.01 ),but the released FGF-1 protein from TT cells in the supernatant fluid was elevated ( P＜0.05 or P＜0.01).Confocal laser scanning of Ca2+ imaging indicated that [ Ca2+ ] i of serum-deprivation TT cells maintained the relative stabilization within 23 win,but the rapid rise of [ Ca2+ ] i achieved peak value 1.6 μmol/L after 30 min,and remained stable for about 17 win,and thereafter 40 win slowly dropped to a low level From 40 win to 60 win the [ Ca2+ ] i was about 0.3-0.6 μ mol/L.The average [ Ca2+ ] i was higher than that in normal group,EGTA group,and BAPTA-AM group within 1 h.The protein expressions of S100A13 and FGF-1 did not drop obviously in EGTA group and BAPTA-AM group.Conlusion The release of S100A13 and FGF-1 from TT cell under serum-deprivation is possibly related with the change of [ Ca2+ ]i.Both Ca2+-chelating agents EGTA and BA PTA-AM are able to inhibit the rise of [ Ca2+ ] i and release of S100A 13 and FGF-1 from TT cells under serum-deprivation.