摘要
AIM:Toinvestigatetheassociationbetweenendogenousgeneexpressionandgrowthregulationincludingproliferationandapoptosisinducedbytransforminggrowthfactor-β1(TGF-β1)inhumangastriccancer(GC)cells.METHODS:Reversetranscriptionpolymerasechainreaction(RT-PCR)wasperformedtodetectthemaincomponentsoftheTGF-β1/SmadssignalpathwayinhumanpoorlydifferentiatedGCcelllineBGC-823.LocalizationofSmadproteinswasalsodeterminedusingimmunofluorescence.Then,theBGC-823cellswereculturedinthepresenceorabsenceofTGF-β1(10ng/mL)for24and48h,andtheeffectsofTGF-β1onproliferationandapoptosisweremeasuredbycellgrowthcurveandflowcytometry(FCM)analysis.TheultrastructuralfeaturesofBGC-823cellswithorwithoutTGF-β1treatmentwereobservedundertransmissionelectronmicroscope.Theapoptoticcellswerevisualizedbymeansoftheterminaldeoxynucleotidyltransferase(TdT)-mediateddTUPinsitunickend-labeling(TUNEL)method.Meanwhile,theexpressionlevelsofendogenousp15,p21andSmad7mRNAandthecorrespondingproteinsinthecellsweredetectedat1,2and3haftercultureinthepresenceorabsenceofTGF-β1(10ng/mL)bysemi-quantitativeRT-PCRandWesternblot,respectively.RESULTS:TheTGF-β1/SmadsignalingwasfoundtobeintactandfunctionalinBGC-823cells.ThegrowthcurverevealedthemostevidentinhibitionofcellproliferationbyTGF-β1at48h,andFCMassayshowedG1arrestaccompaniedwithapoptosisinducedbyTGF-β1.ThetypicalmorphologicalchangesofapoptosiswereobservedincellsexposedtoTGF-β1.Theapoptosisindex(AI)inTGF-β1-treatedcellswassignificantlyhigherthanthatintheuntreatedcontrols(10.7±1.3%vs0.32±0.06%,P＜0.01).Thelevelsofp15,p21andSmad7mRNAandcorrespondingproteinsincellsweresignificantlyup-regulatedat1h,butgraduallyreturnedtobasallevelsat3hfollowingTGF-β1(10ng/mL)treatment.CONCLUSION:TGF-β1affectsbothproliferationandapoptosisofGCcellsth
出版日期
2005年01月11日（中国期刊网平台首次上网日期，不代表论文的发表时间）
