ChemicallyandbiologicallysynthesizedCPP-modifiedgeloninforenhancedanti-tumoractivityMeongCheolShina,b,JianZhanga,b,AllanE.Davidc,WolfgangE.Trommerd,YoungMinKwone,KyoungAhMinb,JinH.Kimb,VictorC.Yanga,b,⁎aTianjinKeyLaboratoryonTechnologiesEnablingDevelopmentofClinicalTherapeuticsandDiagnosis,SchoolofPharmacy,TianjinMedicalUniversity,Tianjin300070,ChinabDepartmentofPharmaceuticalSciences,CollegeofPharmacy,UniversityofMichigan,428ChurchSt.,AnnArbor,48109,USAcDepartmentofChemicalEngineering,AuburnUniversity,Auburn,AL36849,USAdDepartmentofChemistry,TUKaiserslautern,P.O.Box3049,D-67653Kaiserslautern,GermanyeDepartmentofPharmaceuticalSciences,CollegeofPharmacy,NovaSoutheasternUniversity,3200S.UniversityDr.,Ft.Lauderdale,FL33328,USAabstractarticleinfoArticlehistory:Received15April2013Accepted12August2013Availableonline23August2013Keywords:GeloninLMWPCellpenetratingpeptideCancerRibosome-inactivatingproteinToxinTheineffectivenessofsmallmoleculedrugsagainstcancerhasgeneratedsignificantinterestinmorepotentmac-romolecularagents.Gelonin,aplant-derivedtoxinthatinhibitsproteintranslation,hasattractedmuchattentioninthisregard.Duetoitsinabilitytointernalizeintocells,however,geloninexertsonlylimitedtumoricidaleffect.Toovercomethiscellmembranebarrier,wemodifiedgelonin,viabothchemicalconjugationandgeneticrecom-binationmethods,withlowmolecularweightprotamine(LMWP),acell-penetratingpeptide(CPP)whichwasshowntoefficientlyferryvariouscargosintocells.Resultsconfirmedthatgelonin-LMWPchemicalconjugate(cG-L)andrecombinantgelonin-LMWPchimera(rG-L)possessedN-glycosidaseactivityequivalenttothatofunmodifiedrecombinantgelonin(rGel);however,unlikerGel,bothgelonin-LMWPswereabletointernalizeintocells.CytotoxicitystudiesfurtherdemonstratedthatcG-LandrG-Lexhibitedsignificantlyimprovedtumoricidaleffects,withIC50valuesbeing120-foldlowerthanthatofrGel.Moreover,whentestedagainstaCT26s.c.xenografttumormousemodel,significantinhibitionoftumorgrowthwasobservedwithrG-Ldosesaslowas2μg/tumor,whilenodetectablethe...
