简介：ObjectiveTodetectthecellviabilityandtheexpressionsofstemcellsurfacemarkersafterchemotherapeuticdrugtreatment.MethodsWeobservedthecytotoxiceffectsofthreechemotherapeuticagents[epirubicin(Epi),fluorouracil(5-FU)andcyclophosphamide(Cyc)]inthreecelllines,andthecellviabilitiesafterremovedthesechemotherapeuticagents.ExpressionsofstemcellsurfacemarkersCD44,CD24,CD90,CD14andaldehydedehydrogenase1(ALDH1)inbreastcancercellswereanalyzedbyreal-timePCR.Theposthocanalysis(Tukey’stests)inconjunctionwithone-wayANOVAwasusedforstatisticalanalysis.ResultsTheinitialcytotoxicefficacywasmostnotable.Afterthetreatmentofthesametherapeuticagents,cellviabilitywasdecreasedby64.8%35.14%,32.25%inBT-483cells,66.4%,22.94%and45.88%inMDA-MB-231cells,97.1%,99.5%and76.4%inMCFcells.Thedifferencewassignificantcomparedwiththatbeforetreatment(P=0.000).However,theinhibitoryeffectswerediminishedafterchemotherapeuticagentwithdrawal.Cellviabilitieswereincreasedto167.9%,212.04%and188.66%inMDA-MB-231cellsat48hafterwithdrawal.At72hafterwithdrawal,cellviabilitywasincreasedwithasignificantdifferenceinthreecelllines(allPvalues=0.000).ExpressionsofCD44andALDH1weremostprevalentforMDA-MB-231,BT-483andMCF-7cells.ALDH1mRNAlevelwassignificanthigherinBT-483(HER-2overexpressioncellline)thanMDA-MB-231(triplenegativecellline)(P=0.012).CD14mRNAlevelinMCF-7cellsweresignificantlylowerthanthatinMDA-MB-231andBT-483(P=0.003,0.001).BT-483showedsignificantlyhigherlevelofCD44thanMDA-MB-231andMCF-7cellline(P=0.013,0.020),andnosignificantdifferencewasdetectedbetweenMDA-MB-231andMCF-7breastcancercells(P=0.955).CD90mRNAexpressionsweredetectedinMDA-MB-231cellsandMCF-7cells,butnotinBT-483cells.ConclusionSomemalignantcellscouldsurviveinvitroandbegintoproliferateagainbetweencyclesofchemotherapy.