简介：AIM:ToelucidatethemolecularmechanismsunderlyinghepatitisBvirus(HBV)occultinfectionofgenotypeC.METHODS:Atotalof10typesofhepatitisBsurfaceantigen(HBsAg)variantsfromaKoreanoccultcohortwereused.AfteracompleteHBVgenomeplasmidmutatedsuchthatitdoesnotexpressHBsAgandplasmidencoding,eachHBsAgvariantwastransientlyco-transfectedintoHuH-7cells.ThesecretioncapacityandintracellularexpressionoftheHBVvirionsandHBsAgsintheirrespectivevariantswereanalyzedusingreal-timequantitativepolymerasechainreactionassaysandcommercialHBsAgenzyme-linkedimmunosorbentassays,respectively.RESULTS:AllvariantsexhibitedlowerlevelsofHBsAgsecretionintothemediumcomparedwiththewildtype.Inparticular,ineightofthetenvariants,verylowlevelsofHBsAgsecretionthatweresimilartothenegativecontrolweredetected.Incontrast,mostvariants(9/10)exhibitednormalvirionsecretioncapacitiescomparablewith,orevenhigherthan,thewildtype.ThisprovidednewinsightintotheintrinsicnatureofoccultHBVinfection,whichleadstoHBsAgsero-negativenessbuthashorizontalinfectivity.Furthermore,mostvariantsgeneratedhigherreactiveoxidativespeciesproductionthanthewildtype.ThisfindingprovidespotentiallinksbetweenoccultHBVinfectionandliverdiseaseprogression.CONCLUSION:ThepresentlyobtaineddataindicatethatdeficiencyinthesecretioncapacityofHBsAgvariantsmayhaveapivotalfunctionintheoccultinfectionsofHBVgenotypeC.

简介：AIM:ToinvestigatetheroleoftheoverexpressionofB7-H3inapoptosisincolorectalcancercelllinesandtheunderlyingmolecularmechanisms.METHODS:SW620cellsthathighlyoverexpressedB7-H3(SW620-B7-H3-EGFP)andHCT8cellsstablytransfectedwithB7-H3shRNA(HCT8-shB7-H3)werepreviouslyconstructedinourlaboratory.CellstransfectedwithpIRES2-EGFPwereusedasnegativecontrols(SW620-NCandHCT8-NC).Real-timePCRandwesternblottinganalysiswereusedtodetectthemRNAandproteinexpressionsoftheapoptosisregulatorproteinsBcl-2,Bcl-xlandBax.Acellproliferationassaywasusedtoevaluatethesurvivalrateanddrugsensitivityofthecells.Theeffectofdrugresistancewasdetectedbyacellcycleassay.Activecaspase-3westernblottingwasusedtoreflecttheanti-apoptoticabilityofcells.WesternblottingwasalsoperformedtodeterminetheexpressionofproteinsassociatedwiththeJak2-STAT3signalingpathwayandtheapoptosisregulatorproteinsafterthetreatmentwithAG490,aJak2specificinhibitor,inB7-H3overexpressingcells.ThedatawereanalyzedbyGraphPadPrism6usinganon-pairedt-test.RESULTS:WhetherbyoverexpressioninSW620cellsordownregulationinHCT8,B7-H3significantlyaffectedtheexpressionofanti-andpro-apoptoticproteins,atboththetranscriptionalandtranslationallevels,comparedwiththenegativecontrol(P<0.05).AcellproliferationassayrevealedthatB7-H3overexpressionincreasedthedrugresistanceofcellsandresultedinahighersurvivalrate(P<0.05).Inaddition,theresultsofcellcycleandactivecaspase-3westernblottingprovedthatB7-H3overexpressioninhibitedapoptosisincolorectalcancercelllines(P<0.05).B7-H3overexpressionimprovedJak2andSTAT3phosphorylationand,inturn,increasedtheexpressionofthedownstreamanti-apoptoticproteinsB-cellCLL/lymphoma2(Bcl-2)andBcl-xl,basedonwesternblotting(P<0.05).AftertreatingB7-H3overexpressingcellswiththeJak2-specificinhibitorAG490,thephosphorylationofJak2andSTAT3,andtheexp