Rapidlyproliferatingcancercellsgeneratereactiveoxygenspecies(ROS)thatifleftuncheckedinhibitcell growth.Tocounterthisstress,cancercellsandinparticularnonsmallcelllungcancers(NSCLC)relyonthe activationoftheNRF2transcriptionfactor,leadingtothemassiveupregulationofkeymetabolicand detoxificationproteinsneededtorestoreredoxbalance.WhiledirectlytargetingNRF2withchemicalinhibitors ischallenging,wehypothesizedthathyperactivationofthispathwaywouldleadtoanalterationofspecific signalingandmetabolicpathwaysrequiredfortheproliferationofthesecells(co-dependencies),which themselvescouldbeinhibitedwithsmallmolecules.Toidentifytheseco-dependenciesinNSCLC,weenriched forproteinscontainingreactivecysteines,whichcanbeusedasachemicalhandletodevelopinhibitors.This chemicalproteomicsscreenidentifiedhundredsofreactivecysteinesregulatedbyNRF2,includingacryptic cysteine(C274)intheorphanreceptorNR0B1.NR0B1expressionisseverelyrestrictedtothoseNCSLCcells andpatienttumorswithderegulatedNRF2signaling,whereitfunctionsaspartofmultimerictranscriptional complextosupporttheNRF2geneexpressionprogram.AsC274inNR0B1isnecessaryforNR0B1-complex formation,weexploitedthisresiduetodevelopasmallmoleculeinhibitorthatcovalentlybindstoit, subsequentlydisruptingtheprotein-proteininteractionsofNR0B1andblockingthegrowthofNRF2-dependent cells,butnotNRF2-independentcells.Thus,wehaverevealedNR0B1asadruggableco-dependencyofthe NRF2pathway.Inthisgrantapplication,webuildonourresearchonNR0B1andfurtheridentifyco-dependent pathwayswithNRF2thatcanbepharmacologicallyinterrogated.Usingapowerfulchemoproteomic framework,wewillcomprehensivelydefineNRF2co-dependenciesby:1)mappingthelandscapeofcysteine reactivityregulatedbyNRF2inlungxenograftmodels,allowingustoidentifycysteinesonkeyproteinsinthe NRF2pathway,whichmaybecometargetableopportunitiesinvivo2)undertakingasmallmoleculescreento identifycompoundsthatselectivelyinhibittheproliferationofNRF2-dependentNSCLCcelllines.Importantly, integratingachemoproteomicplatformintothisscreen,willallowfortherapididentificationofco-dependent proteins,offeringanunparalleledmapofdruggableNRF2co-dependencies.Theresearchproposedherein, takesfulladvantageofadvancedcancermodelsandchemoproteomictechnologiestoreveal pharmacologicallytractableproteinswhichareneededfortheproliferationofNRF2-addictedcellsandmay provideageneralizableplatformforinhibitinggeneticallydefinedcancers.Thesestudieswillnotonlyprovidea comprehensiveunderstandingofNRF2biologybutmightalsolaythefoundationfortranslationaltherapeutics benefitinglungcancerpatientswithderegulatedNRF2signaling.

Public Health Relevance

TheNRF2transcriptionfactororchestratesthecellularanti-oxidantresponse,promotinganenvironment conducivetouncheckedcellgrowth.Notsurprisingly,NRF2becomeshyperactivatedbyoncogenicmutationin greaterthan30%ofnonsmallcelllungcancers(NSCLCs),afamilyofdevastatingmalignancieswithfew viabletreatmentoptions.Thegoalofthisapplicationistouseasuiteofadvancedchemicalandproteomic technologiestounderstandhowtheNRF2controlledcellularenvironmentisrequiredforcellproliferationand todeveloppharmacologicalagentstargetingproteinsrequiredforthegrowthofNRF2-dependentNSCLCcells.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Career Transition Award (K99)
Project #
1K99CA215249-01
Application #
9294607
Study Section
Subcommittee I - Transistion to Independence (NCI)
Program Officer
Schmidt, Michael K
Project Start
2017-04-01
Project End
2019-03-31
Budget Start
2017-04-01
Budget End
2018-03-31
Support Year
1
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Scripps Research Institute
Department
Type
DUNS #
781613492
City
La Jolla
State
CA
Country
United States
Zip Code
92037