黄俊辉等.Reversal effect of MIF on adriamycin resistan

ReversaleffectofMIFonadriamycinresistanceinhumanbreastcancercelllineMCF-7/ADRHuangJunhui,HuangYuting,ZhangXibei,ZhangYi,XIAOJia,LiuLi,QiuXiao,YingGuaoyong（DepartmeentofOncology,XiangyaHospital,CentralSouthUniversity,Changsha,Hunan,410008）ABSTRACTObjective:Toexplorethereversaleffectofmifepristone(MIF)onadriamycin（ADR）resistanceinhumanbreastcancercellsMCF-7/ADRbymeansofanimalmodelandinvitroexperiments.Methods:1.establishedthemodelofMCF-7/ADRthexenograftonnudemice,treatedwith30mg/kgMIF,observedtheeffectsofMIFonthegrowthofexplantedtumor;2.Theexperimentalgroup(MCF-7/ADR)andcontrolgroup(MCF-7)weretreatedwithMIFofdifferentconcentrations;MTT(4,5-dimethylthiazol-2-yl)andFlowCytoMeter(FCM)assayswereusedtodetectthetoxicconcentration,halfinhibitionratio,drugresistancereversalfold,theexpressionofP-glycoprotein(P-gp),theintracellularfluorescencestorageamountofADRandthedistributionoftumorcellcycles.Results:1.83.33%(20/24)ofthexenograftonmicecouldbeobservedoneweekafterthetransplantationofMCF-7/ADRcells.ThetumorweightofADR+MIFgroup(0.20±0.38g)waslowerthanthatofthecontrolgroup(0.91±0.23g),MIFgroup(0.76±0.47g)andADRgroup(0.48±0.17g)(P＜0.05).TheweightofADRgroupwaslowerthanthatofthecontrolgroupandMIFgroup(P＜0.05);TheweightinhibitionratesofADR+MIFgroup,MIFgroupandADRgroupwere78.0%、16.5%and47.3%.TheweightinhibitionrateofADR+MIFgroupwashigherthanthatofADRgroupandMIFgroup(P＜0.05),butitwashigherinADRgroupthanthatofMIFgroup(P＜0.05).2.TheinhibitionrateofMCF-7/ADRcellstreatedwith5μmol/LMIFwaslowerthan5%.therewasnostatisticalsignificancebetween5μmol/LMIFgroupandthecontrolgroup(0μmol/LMIF)(P0.05).Withtheconcentrationrise,theinhibitionratewasincreased(P＜0.05).TheIC50ofADRforMCF-7/ADRcellswas17.21mg/L,andforMCF-7cellswas0.42mg/L,whichwassignificantlylowerthantheformer(P＜0.05).WhenMCF-7/ADRcellsweretreatedwithADRcombinedwith5μmol/LMIF,theIC50ofADRwas1.96mg/L,whichwassignificantlylowerthanthatofADRgroup(17.21mg/L)(P＜0.05).Thedrugresistancereversalfoldwas8.78.3.TheexpressionrateofP-gpinMCF-7/ADRcellswas64.77±3.21%beforetreatedwithMIF,whichwassignificantlyhigherthanthatinMCF-7cells(38.22±1.76)%(P0.01).BoththeexpressionrateofP-gpinMCF-7/ADRcells(23.21±1.80)%andMCF-7cells(19.37±2.37)%aftertreatedwith5μmol/LMIFwerelowerthantheratesbeforethetreatment(P＜0.05).However,therewasnostatisticalsignificancebetweentheexpressionrateoftwokindsofcells(P0.05).4.ThefluorescencestorageamountofADRintracellularinMCF-7/ADRwas(47.13±4.11)%aftertreatedwith5μmol/LADR,,whichwaslowerthanthatinMCF-7(60.24±2.61)%(P＜0.05).Afterthetreatmentof5μmol/LADRcombinedwith5μmol/LMIF,boththefluorescencestorageamountofADRintracellularinMCF-7/ADR(82.72±2.42)%andMCF-7(88.63±2.75)%werehigherthanthatwithouttheMIFtreatment(P0.01),buttherewasnostatisticalsignificancebetweentwokindsofcells(P0.05).5.TherateofG0/G1stageinMCF-7was(59.05±2.16)%.ThisrateinMCF-7/ADRwas(77.21±3.10)%.aftertreatedwith0μmol/LMIF,thelatteronewassignificantlyhigherthantheformer(P＜0.05).Incontrast,therateofSstageinMCF-7/ADRwassignificantlylowerthanthatinMCF-7(P＜0.05).Afterthetreatmentof5μmol/LMIF,therateofG0/G1stageinMCF-7(75.28±2.53)%wassignificantlyhigherthanthegroupwith0μmol/LMIF(P＜0.05)andtherateofSstageinMCF-7cellswassignificantlylowerthanthegroupwith0μmol/LMIF(P＜0.05).TherateofG0/G1andSstageinMCF-7/ADRwas(80.13±2.72)%and(13.52±1.03)%afterthetreatmentwithMIF,whichwerenostatisticalsignificancewhencomparedwiththosetreatedwith0μmol/LMIF(P0.05);TherewasenostatisticalsignificanceamongtheratesofG2/Mstageinallgroupsofcells(P0.05).Conclusion:1.MIFcouldreversethedrugresistanceofMCF-7/ADRinvivoandinvitroexperiments.2.MIFreversedthedrugresistanceofMCF-7/ADRthroughreducingtheexpressionofP-gpintracellularwhichinducedthealterationofdrugconcentrationsinsideandoutsideofthecells.3.5μmol/LMIFcouldnotaffecttheinhibitionrateanddistributionofcellcyclesofMCF-7/ADRsignificantly.Itindicatedthat5μmol/LMIFcouldberegardedastheconcentrationinvitroexperiments.However,theconcentrationinvivostillneedsfurtherexploration.KEYWORDS:MIF;MCF-7;MCF-7/ADR;reverse;ADRresistanceAdriamycin(ADR)isoneofthecommondrugsusedforthebreastcancer.However,themultidrugresistanceofthebreastcancercellsoftencausesthefailureofthechemotherapytreatment[1].Sofindaproperdrugormethodtoovercometheproblemhasbecomeahotspotofthetumorresearchatpresent.Mifepristone(MIF)isoneofthederivativesofnorethisteroneandprimaryusedforstoppingpregnancy.Recentlywiththefurtherstudiesonpharmacologicalandbiologicalcharacteristics,peoplefoundthatMIFcanreversethemultidrugresistanceinvitro[2].IthasbeenshownthatMIFcanreversethedrugresistanceoflungandovariancancercellsandsoon[3-4].However,therewasinconsistencyamongdifferentstudiesandfurthermore,littlehasbeendoneinin-vivostudies.ThemechanismofthereversaleffectofMIFondrugresistanceindrug-resistanthumanmammarycancercellsisstillnotclear.Inthisstudy,weuseMCF-7andMCF-7/ADRcelllinesasmodelstoinvestigatethemechanismofthereversaleffectofMIFondrugresistanceinMCF-7/ADRcelllinebymeansofinvitro,invivoandanimaltransplantabletumormodels.1MaterialsandMethods1.1Mat