The multiple usages of Notch signaling in development, cell differentiation and cancer
Anna Bigas and Lluis Espinosa
Notchisawell-conservedsignalingpathwayallthrough evolutionthatiscrucialtospecifydifferentcellfates.Although thereisastrongcontextdependentcomponentineach decision,thebasicmechanismsthatoriginatefromthe interplayamongligandsandreceptorsisgreatlypreserved.In thisreviewwewillcoverthelatestfindingsonthedifferent mechanismsforNotchactivationandsignaling.Theregulation ofthispathwayisessentialtounderstanddevelopment,cell differentiationanddisease.
Address
PrograminCancerResearch,InstitutHospitaldelMard’Investigacions Me`diques(IMIM),CIBERONC,Barcelona,Spain
Correspondingauthors:Bigas,Anna([email protected]),Espinosa,Lluis ([email protected])
CurrentOpinioninCellBiology2018,55:1–7
ThisreviewcomesfromathemedissueonDifferentiationand disease
EditedbyKatjaRo¨perandXose´ RBustelo
ForacompleteoverviewseetheIssueandtheEditorial Availableonline10thJuly2018
https://doi.org/10.1016/j.ceb.2018.06.010 0955-0674/ã2018ElsevierLtd.Allrightsreserved.
Introduction
Notch signals arekey playersin cellfatedecisions that involve cell–cell interactions. The Notch system is a widely used mechanism to generate cell diversity and maintain tissue integrity [1]. Through the expression levelsofligandsandreceptorspresentinnearbyequipo- tentcells, Notchresponseisableto providedirectional signalsintooneofthecellsthataffecttheoutcomeofthat cell and its neighbors. Thisis important for tissue pat- terningandcanbeinducedbyupregulationofaparticular Notch ligandin one or agroup of cells, thus creatinga cascadeofsignalsinadjacentcells.Lateralinhibitionand lateralinductionarethemostcommonmodelsthathave been proposed to explainhowNotch signals arepropa- gated in nearby cells. Since Notch pathway is highly conserved all along the evolution, invertebrate model organisms such as Caenorhabditis elegans and Drosophila have been used to study the mechanism underlying Notchregulationand function.
Underphysiologicalconditions,Notchsignalingiswork- ingessentiallyinalldifferenttissuesbothduringembry- onicdevelopmentandintheadulthood.Theversatilityof thispathwayiswhatprovidestheenormousdiversityof outcomesthatarerequiredtogeneratecellandorganisms diversificationduringevolutionaryadaptation.However, uncontrolled Notch regulation can also result in unde- siredlife-threateningeffects,includingdifferenttypesof cancer.
Inthisreview,wewillsummarizethemostrecentdataon themechanismsusedbytheNotchpathwaytoregulate celldecisions,tissuehomeostasisandcancer.Wewillalso discuss thetherapeutic options thatare currently being exploitedin thisfield.
Recent discoveries about Notch signaling
Geneticscreeningsin DrosophilacarriedbyMorganand colleagues at the beginning of the twentieth century identified a genetic alteration that induced notches in thewingmargin.ThisparticularNotchphenotypeiswhat gavenametoallNotchreceptorsandthewholesignaling pathway.Yearslater,Notch,thegeneresponsibleforthis phenotype, was cloned in Drosophila, followed by the identificationofitsorthologuegenesindifferenttypesof vertebrate organisms including humans. The high con- servationofthisfamilyofreceptorsallthroughevolution rapidlysuggestedtherelevanceoftheirfunction.The Notchproteinisacellreceptorthatsuffers several modificationsbeforeitispresentedinthecellularmem- braneinitsfunctionalconformation.Initsmatureform, Notch contains an extracellular domain, a single trans- membranedomainandanintracellulardomain.Receptor activationtakes placebyinteraction oftheextracellular domainofNotchwithligandsofeithertheJagged/Serrate orDeltafamilythatarepresentintheneighboringcells.
ThisinteractionresultsinNotchcleavageatseveralsites bytheactionofdifferentenzymaticactivities,leadingto thereleaseoftheintracellularNotch(NIC)fragmentand subsequent translocation intothe nucleus. Once in the nucleus,NICparticipatesingenetranscriptioninassoci- ationwithitsDNAbindingpartnerCSL/RBPj.Despite thegreatvarietyofNotchtargets,themorecommonand bestcharacterizedaretheHes/EnhancerofSplitfamilyof transcriptionalrepressors.
Theelementsdescribedaboveareconsideredthecoreof theNotchsignaling cascadeandhavebeeninvestigated and revised for many years. However, new ideas are
originating from crystallographic studies, which will be covered in this review, together with other aspects of Notchsignalingthatarereceiving mostattention inthe lastyears (Figure1).
Notch molecules and ligands: lessons from crystallography
Itwas in2006whenthecrystalstructureof theNotch1 activating complex with CSL/RBPj and Mastermind (Mam) was reported [2,3]. These studies were critical tounderstand how Notchworksatthechromatinlevel, andhowwecaninterferewithitsfunctionifrequired.In brief, the NIC domain contains several functional ele- mentsincludingsevenankyrinrepeatsthatarecrucialfor theinteraction with other intracellular andnuclear ele- ments.Theinteraction domainof NICwith CSL/RBPj expands from repeats two to seven, being the seventh repeatspecificallyresponsiblefortheinteractionwiththe Notchco-activatorMam.Recruitmentoftheacetyltrans- ferasep300isindirectandrequiresdepresenceofMam.
The detailed structural characterization of the Notch transcriptionalcomplex ledto the developmentof spe- cificMampeptidesthatactasNotchinhibitorsbybinding to the interaction site of NIC and Mam. Using these peptides,itwasdemonstratedthatNotchinhibitionisa plausiblestrategyto combatT-cell acutelymphoblastic leukemia(T-ALL)[4].
The structural characterization of the Notch ligands interaction with the extracellular domain of Notch has beenhardertoobtain,andonlyrecentlyNotch1–Dll4and Notch1–Jag1crystalstructureshavebeenpublished.The Garcia’s lab developed a strategy to select for mutant ligandswithhigheraffinityforNotch1,thusallowingthe crystallizationof amore stable complex that permitted theanalysis.Fromthesestudies,welearntthatDelta-like 4 binds aglycosylated Notch1 receptor with O-glucose andO-fucosemodificationsofEGFrepeats11–13acting as surrogateaminoacids [5].These modificationswould likely interfere with specific antibodies targeting this particular Notch interaction sites, thus suggesting that othermoleculesthatbindeitherJagor Dllligandswith highaffinity (thus competing Notchbinding) maybea better therapeutic strategy. Antibodies targeting Dll4 haveindeedshowntobeefficientinspecificallyinhibit- ingDll4-deliveredsignals[6]andarepromisingtoolsfor angiogenesis-based anticancer therapy. Several antibo- dies targeting Jag1 have also been developed and are currentlybeing testedfor theirtherapeutic applications [7,8]. Instead, specific Notch blocking antibodies are directed to the negative regulatory region (NRR) of thereceptor, the exposure of which is required for the S2cleavageaccomplished by theADAM10metallopro- tease[9].
Recently, the crystal structure of the Notch1–Jagged1 complex was also resolved [10] showing that Jagged1 bindstoNotch1receptorwhenspecificallyfucosylatedon theEGFrepeats8and12.AssociationbetweenJagged1 andNotchexhibitsacatch bondbehaviorthatprolongs their interactions in the range of cellular forces. As a result,highertensionisrequiredtodissociateNotchfrom
Figure1
CoA CSL
CoR CSL
Cis-inhibition
FNG
FNG FNG
FNG
Dll4-dependent Notch signaling CSL
CoA Jag1-dependent Notch signaling CSL
CoA CSL CoA
CSL
Ligand specificity of signal response Trans-activation
Fringe modifications
Absence of Fringe Presence of Fringe
Pulsatile signal (Dll1) Sustained signal (Dll4) Notch-ligand interactions
FNG
CoR CoA
CSL Notch receptor Jag/Ser ligand Delta ligand Fringe
Kinetics gene expression Coactivators
Corepressors
CSL/RBPJ mRNA Time
Current Opinion in Cell Biology
Notchresponsedependsonthetypeofreceptor–ligandinteraction.
(a)Ligandinaneighbouringcellactivatesthereceptorintheadjacent cell.Instead,aligandpresentedinthesamecellasthereceptorwill preventthereceptortorespondtootherligandsintransandavoid signaling.(b)TheabsenceoffringemodificationintheNotchreceptor favorsJaggedinteractionwhilethepresenceoffringefavorsthe interactionwithDeltaligands.(c)Ligandsinducespecificintensityand durationofNotchsignalingmainlyduetothecapacityofaggregation andrecruitmentofreceptormolecules.Dll1isdescribedasaninducer ofpulsatilesignal,whileDll4aggregatesandinducestheactivationof severalNotchmolecules.
Jagged1thanfromDelta-like4,thus providinganaddi- tional mechanism to discriminate between signals derived fromdifferentNotchligands(Figure1).
Fringe modifications and other
posttranscriptional modifications of Notch receptor
As mentioned in the previous section,modifications of Notchimposedbyspecificglycosyltransferasesareatthe baseofitsselectiveactivationbyJaggedorDeltaligands.
In addition to the sugar moieties thatpofut (O-fucose) andpoglut(O-Glucose)enzymesdeliver,thefringegly- cosyltransferasesareresponsibletoelongatetheO-fucose residuesbyaddingN-acetylglucosamine(GlcNAc)tothe EGFrepeatsofNotch.Therearethreefringeproteinsin mammals: Lunatic,Manicand Radicalthat displaydif- ferent enzymatic and functional properties. Although Lunatic and Manic primarily inhibit Notch1 activation by Jagged1 and enhance activation by Delta, Radical fringeenhancesactivationbybothligands.Onlyrecently, the specific modifications imposed by particular fringe proteinsontheNotch1receptorhavebeenreported.By massspectrometryanalysis,itwasfoundthatLunaticand Manic, but not Radicalfringe, induce similar modifica- tionsofNotch1attheEGFrepeats6and3,thusinhibit- ing Notch1activationbyJagged1[11].Itcaneasilybe anticipatedthat thefunctional consequencesandthera- peuticimplicationsofFringe-mediatedmodificationsare enormous,astheywilldeterminethecapacityofNotchto respond to specific ligands under particular scenarios including cancer. Other post-translational modifications ofeitherNotchorassociatedfactorshavealsobeenshown to regulate Notch signaling. This is the case of Notch SUMOylation that attenuates its activity [12], Notch acetylation leadingto stabilizationoftheNICfragment in endothelialcells lackingSIRT1[13]GSK3-mediated Notch2 phosphorylation in hematopoietic progenitor cells[14]oracetylationofMaml1byp300thatisrequired for initiatingNotch-driventranscription[15].
Functional implications of endocytosis in Notch regulation
Endocytosisisanimportantregulatorymechanismofthe Notchpathway.Ligandsandreceptorsarebothsuscepti- bleof beinginternalizedin differenttypesofendocytic vesiclesthusadjustingtheamountofligandandreceptors thatare availablein thecellmembrane.Asaresult,the strengthandnatureofligand/receptorinteractionsthatin turn translatesintotheamountofNICthatisproduced andentersthenucleustoactivatetranscription(Figure2).
Itisnotonlytheamountofligandsandreceptorswhatis regulatedbythisprocess,butonceNotchispresentatthe cellularmembraneandafterligandbindingendocytosisof thelatterinthesendingcellexertsapullingforceonthe extracellularpartofthereceptor.Inparticular,thisforceis responsiblefordisruptionoftheNRRleadingtoexposure
of the domain containing the S2 cleavage site and the subsequent conformational change that will allow the processingoftheintracellulardomainbytheg-secretase/
presenilincomplexinS3site(reviewedin[16]).
The endocytic machinery required for a proper Notch functionsharessomeelementswiththegeneralendocytic pathway. However some elements are quite specific althoughnotexclusive.Forexample,theE-Ringubiqui- tinligasesNeuralizedandMindbombarekeyregulators ofNotchligandsubiquitination,whicheventuallydeter- mines their functionality[17]. Recently, it was demon- strated that the Epsin adaptor protein is essential to facilitate ligand endocytosis by the signal-sending cell afterNotchcleavagethusprovidingthesufficientpulling force required for S2 exposure and Notch signaling.
Otherwise, ligand is transendocytosed by the Notch- expressing cellandtheNotchsignalisaborted[18].
The proper control of the endocytic machinery is also responsible for delivering polarized/unequal Notch sig- nals at a single cell level, thus providing the base for asymmetric celldivision(reviewedby[19]).
Non-conventional mechanisms for Notch signal regulation
The canonical mechanism thatleads to Notchpathway activationisbasedontheinteractionsofNotchreceptor withitsligandpresentedinaneighboringcell,cleavageof the Notch receptor in two different sites (S2 and S3) resultingin NICrelease,NICnucleartranslocationand activationofspecificgenetranscription.Althoughmostof our understanding of Notch functions is related to this type of activation, there aremultiple exceptionsto this linearregulationofthereceptor.Forexample,Drosophila Deltexwasfoundtopromoteligandindependentactiva- tionofNotchintheendosomalcompartmentofthecells in a presenilin-dependent manner [20]. In the same animal model, the group of Gonza´lez-Gaita´n proposed a mechanism in which ligand–receptor binding takes place within multivesicular endosomes of single cells, which express the Sara protein, and drive directional Notch activation during asymmetric cell division [21].
Thisbindingoccursinananti-parallelconfiguration(the samethatisfoundinthecanonicaltrans-interaction),as opposedtotheparallelbindingthatiscommonlyassoci- ated to cis-interactions (between receptors and ligands present in the membrane of the same cell) that are believed to prevent signaling(known as cis-inhibition).
Interestingly, differential inheritance of theSara endo- somesintheintestinalstemcellcompartmentleadingto asymmetric cell division compartment is required to maintain the homeostasis of the intestinal lineages in Drosophila[22](Figure 2).
Assuggestedfromstructuralstudies,differentlevelsof Notchactivationmaydependonthepullingforcethatis
providedfromtheligand.Inarecentstudy,theEllowitz labshedsomelightintothequestionofhowdifferentis Notch signaling depending on the ligand involved. In particular,theydemonstrated that Notch signal activa- tionispulsatileandsustaineddependingonthetypeof ligand and theway it aggregates inthecellmembrane [23]. By measuring Hes1 transcriptional activity asa surrogateforNotchactivation, theauthorsdemonstrate thatpulsatilesignalinginvolvesclusteringofDll1while sustainedsignalingimposedbyDll4isligandclustering- independent.Thus,ageneralconclusionwouldbethat differentlevelsandamplitudeofNotchsignal,whichare achievedbythecombinatoryeffectofligandandrecep- tor availability, Fringe-mediated modifications leading to ligand discrimination, differences in the endocytic pathway,cis-inhibition ortrans-inhibition and intracel- lularsignaling,canprovideacomprehensiveexplanation tomostofthereportedobservationsonthediverserole ofNotchincellfatedecisionssuchasthoseinvolvedin hematopoieticstemcelldetermination[24],tissueand stemcellhomeostasis[25]andoncogenictransformation [26].
Apartfromitsintracellularfunctionastranscriptionfactor inassociation withCSL/RBPjandMam,severalreports
havedescribedinteractionswithother transcriptionfac- tors and regulators. Thus, Notch can interact with the IKK kinases to regulate transcriptionin cervical cancer cells [27] and T-ALL [28]. In endothelial cells, shear stress is sufficient to promote Dll4-dependent Notch cleavageto exposetheNotch1 transmembranedomain, which mediates the establishment of the endothelial barrierin atranscriptional-independentmanner [29].
Notch in cancer
Notch activity has been extensively linked to cancer whereitcanexert bothtumor suppressorand promoter activity depending on the cellular context. One of the best-characterizedrolesofNotchastumorsuppressorwas foundinthemouseskin.Inparticular,Notchactivityis required in keratinocytes to maintain the skin barrier integrity.Intheabsenceof epidermalNotch,aninflam- matoryresponseisinitiatedleadingtoinductionofthy- micstromallymphopoietin(TSLP)thatactsas atumor suppressor. Loss of TSLP receptor in the context of Notch deficient skin results in skin carcinogenesis [30,31].BycontrastintestinalNotch1actsastumorpro- moter [26,32] by blocking differentiation of adenoma cells into the secretory pathway [33]. Interestingly enough, in APC-mutated adenoma cells, activation of
Figure2
CoA CSL Notch receptor Jag/Ser ligand Delta ligand
Coactivators CSL/RBPJ
Numb/Neu expression
Asymmetric cell division Sara endosomes
CoA CSL
Cell with Numb And Neuralized
Endosomal pathway
CoA CSL
Current Opinion in Cell Biology
EndosomalregulationofNotchsignaling.(a)UbiquitinationoftheligandandthepresenceofEpsinandclathrinendocyticvesicleswillproducea pullingforcethatwillactivatetheNotchreceptorwhentheybind.InsteadtheabsenceoftheclathrinandEpsinendosomeswillresultinthe endocytosisofthereceptorwiththeboundligandinthereceivingcell.Theabsenceofpullingwillblocktheactivationofthereceptorandthe signalwillbeabortedandthemoleculeswilldegrade.Alternatively,theubiquitinationofthereceptormayleadtorecyclingtothemembrane.(b) AsymmetriccelldivisionwillproduceasymmetricNotchsignalbytheinheritanceofSARAendosomeswithNotchandligandthatwillallowthe activationofNotchwithintheendosome.IfthecellthatinheritstheSARAendosomeshasNumbandNeuralized,theendosomeswillbe degraded.
Notch is dependenton thesignalprovided byJagged1 that is transcriptionally induced downstream of beta- catenin [26], one of the main tumor promoters in the intestine.
Notch1activationisalsoapivotaltumordriverinhumanT- ALL.Therefore,50%ofthesetumorscarrymutationsin eithertheNotchmoleculeitself[34]orinelementsofthe Notchpathwayleadingtoaberrantactivationofthepath- way[35].Interestingly,NotchactivationintransformedT cells directly impacts in another relevant cancerdrivers suchasNF-kBpathway[36].SinceT-ALLhasbeenan importantdiseasemodeltostudyNotchregulations,many interactorshavebeen identifiedintheseleukemiccells.
ForexampleVav1regulationofNotchstability[37]and b-catenin collaboration in transcriptional activity [38], among others. Mutations in Notch1,Notch2 and Fbw7 have also been found in chronic lymphocyticleukemia (CLL)[39]andindiffuselargeB-celllymphoma[40].
Activation ofdifferentNotchhomologueswasalsofound associatedwithmalignancyinmultiplesolidcancertypes suchas squamouscellcarcinoma [41],thyroidcarcinoma [42], melanoma [43], cutaneous T-cell lymphoma and mycosis fungoides [44] but the molecular mechanisms underlying this association are not well-established.
Directly relatedwithbreast cancertherapy,itwasfound thatJagged1isinducedbychemotherapyintheosteoblast thus promoting bone metastasis of breast cancer cells throughNotchactivation.Inthissystem,combinationther- apyinvolvinganti-Jagged1blockingantibodiesprevented tumormetastasisandreducedalreadyestablishedlesions [45]. Recently,activated Notch3 was alsofound to be particularly relevant in several types of cancer including liver cancer[46], basal breast cancer [47]and melanoma[48].
Concluding remarks
TheNotchsignalingpathwayisarobustcellfateregulator, crucialtogeneratecellulardiversificationduringmorpho- genesis andessential intheadulthood forstem cell and tissuemaintenance.To accomplishthisessentialmissionin multiplecelltypesandtissues,Notchactivationdisplays exquisite ligand selectivity that is particularly relevant whenitdiscriminatesbetweenphysiologicandpathologic conditions. Thus, much work should be done to better understandthemechanismsunderlyingligand-dependent Notchactivation and the downstreamelements thatare responsiblefortheplethoraofoutcomesthatNotchaccom- plishes.DissectingthemechanismsleadingtoNotchfunc- tionselectivitywillofferauniquepossibilitytomanipulate thepathwayfortherapeuticpurposes.
Acknowledgments
WewouldliketothankErikaLo´pez-Arribillagaforhelpinthefiguredesignand themembersoftheBigasandEspinosalabforhelpfuldiscussions.Ourresearch isfundedbyMinisteriodeEconomı´ayCompetitividad(SAF2016-75613-R),
Fundacio´nAECC(Gruposconsolidados),Age`nciadeGestio´ d’Ajuds UniversitarisideRecerca(AGAUR)(2017SGR135)andPERIS-(SLT002/16/
00299)toABandInstitutodeSaludCarlosIII(PI16/00437)toLE.
References and recommended reading
Papersofparticularinterest,publishedwithintheperiodofreview, havebeenhighlightedas
ofspecialinterest ofoutstandinginterest
1. HoriK,SenA,Artavanis-TsakonasS:Notchsignalingata glance.JCellSci2013,126:2135-2140.
2. NamY,SlizP,SongL,AsterJC,BlacklowSC:Structuralbasisfor cooperativityinrecruitmentofMAMLcoactivatorstoNotch transcriptioncomplexes.Cell2006,124:973-983.
3. WilsonJJ,KovallRA:CrystalstructureoftheCSL–Notch–
MastermindternarycomplexboundtoDNA.Cell2006, 124:985-996.
4. MoelleringRE,CornejoM,DavisTN,DelBiancoC,AsterJC, BlacklowSC,KungAL,GillilandDG,VerdineGL,BradnerJE:
DirectinhibitionoftheNOTCHtranscriptionfactorcomplex.
Nature2009,462:182-188.
5. LucaVC,JudeKM,PierceNW,NachuryMV,FischerS,GarciaKC:
Structuralbiology.StructuralbasisforNotch1engagementof Delta-like4.Science2015,347:847-853.
6. YanM,PlowmanGD:Delta-like4/Notchsignalingandits therapeuticimplications.ClinCancerRes2007,13:7243-7246.
7. LafkasD,SheltonA,ChiuC,deLeonBoenigG,ChenY, StawickiSS,SiltanenC,ReicheltM,ZhouM,WuXetal.:
TherapeuticantibodiesrevealNotchcontrolof
transdifferentiationintheadultlung.Nature2015,528:127-131.
8. Lo´pez-ArribillagaE,RodillaV,SheltonA,ChengJ,YanB, ColomerC,Gonzalez-PerezA,JunttilaMR,IglesiasM,AlbanellJ etal.:ManicFringedeficiencyimposesJagged1addictionto intestinaltumorcells.NatCommun2018.inpress.
ThisworkdemonstratestherelevanceofManicFringefordefiningthe addictionofcolorectalcancercellstoaparticularNotchligand,inthis caseJagged1.Thus,tumorswithhighNotchactivityandnegativefor Manic fringe expression are particularly sensitive to the genetic or pharmacologicinhibitionofJagged1.
9. GrootAJ,HabetsR,YahyanejadS,HodinCM,ReissK,SaftigP, TheysJ,VooijsM:RegulatedproteolysisofNOTCH2and NOTCH3receptorsbyADAM10andpresenilins.MolCellBiol 2014,34:2822-2832.
10. LucaVC,KimBC,GeC,KakudaS,WuD,Roein-PeikarM, HaltiwangerRS,ZhuC,HaT,GarciaKC:Notch–Jaggedcomplex structureimplicatesacatchbondintuningligandsensitivity.
Science2017,355:1320-1324.
InthispaperitisshownthatinteractionofNotchwithDeltaorJagged ligands defines the mechanical force that is required for disrupt its interaction.Inthecontextofthecellularforces,thisspecifiestheduration oftheinteraction,whichprovidesanadditionalmechanismforcontext- dependentNotchsignaldiscrimination.
11.
KakudaS,HaltiwangerRS:Decipheringthefringe-mediated notchcode:identificationofactivatingandinhibitingsites allowingdiscriminationbetweenligands.DevCell2017, 40:193-201.
ThisarticledemonstrateforthefirsttimethatdifferentFringeglycosyl- transferasesmodifyNotchasspecificregionsoftheextracellularEGF repeatsthusimposingadifferentialcapacityfor ligandselectivityand ligand-dependentactivation.
12.
AntilaCJM,RraklliV,BlomsterHA,DahlstromKM,SalminenTA, HolmbergJ,SistonenL,SahlgrenC:SumoylationofNotch1 repressesitstargetgeneexpressionduringcellstress.Cell DeathDiffer2018,25:600-615.
ThisarticleuncoverSUMOylationasanovelpost-translationmodification thataffectsNotchactivity.Thisisparticularlyinterestingbecauseofthe increasingrelevancethatSUMOmodificationsareacquiringinthedif- ferentsignalingpathways.
13. GuaraniV,DeflorianG,FrancoCA,KrugerM,PhngLK,BentleyK, ToussaintL,DequiedtF,MostoslavskyR,SchmidtMHetal.:
Acetylation-dependentregulationofendothelialNotch signallingbytheSIRT1deacetylase.Nature2011,473:234-238.
14. EspinosaL,Ingles-EsteveJ,AguileraC,BigasA:Phosphorylation byglycogensynthasekinase-3betadown-regulatesNotch activity,alinkforNotchandWntpathways.JBiolChem2003, 278:32227-32235.
15. JinK,ZhouW,HanX,WangZ,LiB,JeffriesS,TaoW,RobbinsDJ, CapobiancoAJ:Acetylationofmastermind-like1byp300 drivestherecruitmentofNACKtoinitiatenotch-dependent transcription.CancerRes2017,77:4228-4237.
16. vanTeteringG,VooijsM:ProteolyticcleavageofNotch:‘‘HIT andRUN".CurrMolMed2011,11:255-269.
17. DaskalakiA,ShalabyNA,KuxK,TsoumpekosG,TsibidisGD, MuskavitchMA,DelidakisC:Distinctintracellularmotifsof DeltamediateitsubiquitylationandactivationbyMindbomb1 andneuralized.JCellBiol2011,195:1017-1031.
18. LangridgePD,StruhlG:Epsin-dependentligandendocytosis activatesNotchbyforce.Cell2017,171:1383-1396e1312.
19. Perez-MockusG,SchweisguthF:Cellpolarityandnotch signaling:linkedbytheE3UBIQUITINLIGASENEURalized?
Bioessays2017,39.
20. WilkinM,TongngokP,GenschN,ClemenceS,MotokiM, YamadaK,HoriK,Taniguchi-KanaiM,FranklinE,MatsunoKetal.:
DrosophilaHOPSandAP-3complexgenesarerequiredfora Deltex-regulatedactivationofnotchintheendosomal traffickingpathway.DevCell2008,15:762-772.
21. CoumailleauF,FurthauerM,KnoblichJA,Gonzalez-GaitanM:
DirectionalDeltaandNotchtraffickinginSaraendosomes duringasymmetriccelldivision.Nature2009,458:1051-1055.
22. MontagneC,Gonzalez-GaitanM:Saraendosomesandthe asymmetricdivisionofintestinalstemcells.Development 2014,141:2014-2023.
23.
NandagopalN,SantatLA,LeBonL,SprinzakD,BronnerME, ElowitzMB:Dynamicliganddiscriminationinthenotch signalingpathway.Cell2018,172:869-880e819.
Thisarticleprovidesanimportantclueaboutthedifferenttranscriptional outcomethatresultsfromNotchactivationbyDll1andDll4ligands.In particular,theydemonstratethatpulsatilesignalinginvolvesclusteringof Dll1whilesustainedsignalingthatisimposedbyDll4doesnotinvolve ligandclustering.
24.
Gama-NortonL,FerrandoE,Ruiz-HerguidoC,LiuZ,GuiuJ, IslamAB,LeeSU,YanM,GuidosCJ,Lopez-BigasNetal.:Notch signalstrengthcontrolscellfateinthehaemogenic endothelium.NatCommun2015,6:8510.
ThisworkshowsthatitisatightlycontrolleddoseofNotch1activitythat permitsthetransformationoftheendothelial-likeprecursorsinthemouse embryo intohematopoieticprogenitorsand stem cells. In fact, authorshows adifferentialrequirementfortheNotchligandJagged1inthisprocess.
25. Lopez-ArribillagaE,RodillaV,PellegrinetL,GuiuJ,IglesiasM, RomanAC,GutarraS,GonzalezS,Munoz-CanovesP,Fernandez- SalgueroPetal.:Bmi1regulatesmurineintestinalstemcell proliferationandself-renewaldownstreamofNotch.
Development2015,142:41-50.
26. RodillaV,VillanuevaA,Obrador-HeviaA,Robert-MorenoA, Fernandez-MajadaV,GrilliA,Lopez-BigasN,BelloraN,AlbaMM, TorresFetal.:Jagged1isthepathologicallinkbetweenWnt andNotchpathwaysincolorectalcancer.ProcNatlAcadSciU SA2009,106:6315-6320.
27. SongLL,PengY,YunJ,RizzoP,ChaturvediV,WeijzenS, KastWM,StonePJ,SantosL,LoredoAetal.:Notch-1associates withIKKalphaandregulatesIKKactivityincervicalcancer cells.Oncogene2008,27:5833-5844.
28. VilimasT,MascarenhasJ,PalomeroT,MandalM,BuonamiciS, MengF,ThompsonB,SpauldingC,MacarounS,AlegreMLetal.:
TargetingtheNF-kappaBsignalingpathwayinNotch1- inducedT-cellleukemia.NatMed2007,13:70-77.
29. PolacheckWJ,KutysML,YangJ,EyckmansJ,WuY,VasavadaH, HirschiKK,ChenCS:Anon-canonicalNotchcomplexregulates
adherensjunctionsandvascularbarrierfunction.Nature2017, 552:258-262.
30. DemehriS,TurkozA,ManivasagamS,YockeyLJ,TurkozM, KopanR:Elevatedepidermalthymicstromallymphopoietin levelsestablishanantitumorenvironmentintheskin.Cancer Cell2012,22:494-505.
31. DiPiazzaM,NowellCS,KochU,DurhamAD,RadtkeF:Lossof cutaneousTSLP-dependentimmuneresponsesskewsthe balanceofinflammationfromtumorprotectivetotumor promoting.CancerCell2012,22:479-493.
32. FreS,PallaviSK,HuygheM,LaeM,JanssenKP,RobineS, Artavanis-TsakonasS,LouvardD:NotchandWntsignals cooperativelycontrolcellproliferationandtumorigenesisin theintestine.ProcNatlAcadSciUSA2009,106:6309-6314.
33. vanEsJH,vanGijnME,RiccioO,vandenBornM,VooijsM, BegthelH,CozijnsenM,RobineS,WintonDJ,RadtkeFetal.:
Notch/gamma-secretaseinhibitionturnsproliferativecellsin intestinalcryptsandadenomasintogobletcells.Nature2005, 435:959-963.
34. WengAP,FerrandoAA,LeeW,MorrisJPT,SilvermanLB, Sanchez-IrizarryC,BlacklowSC,LookAT,AsterJC:Activating mutationsofNOTCH1inhumanTcellacutelymphoblastic leukemia.Science2004,306:269-271.
35. ThompsonBJ,BuonamiciS,SulisML,PalomeroT,VilimasT, BassoG,FerrandoA,AifantisI:TheSCFFBW7ubiquitinligase complexasatumorsuppressorinTcellleukemia.JExpMed 2007,204:1825-1835.
36. EspinosaL,CathelinS,D’AltriT,TrimarchiT,StatnikovA,GuiuJ, RodillaV,Ingles-EsteveJ,NomdedeuJ,BellosilloBetal.:The Notch/Hes1pathwaysustainsNF-kappaBactivationthrough CYLD repression inTcell leukemia.CancerCell2010,18:268-281.
37. Robles-ValeroJ,Lorenzo-MartinLF,Menacho-MarquezM, Fernandez-PisoneroI,AbadA,CamosM,ToribioML,EspinosaL, BigasA,BusteloXR:Aparadoxicaltumor-suppressorrolefor therac1exchangefactorVav1inTcellacutelymphoblastic leukemia.CancerCell2017,32:608-623e609.
TherelevanceofthisworkisthedemonstrationthatVav1actsastumor suppressorinimmatureT-cellsthroughregulationofNotch1degradation imposedbyCbl-b.LossofVav1enhancesNotchactivitythusinducingT- ALLdevelopment.
38. GekasC,D’AltriT,AligueR,GonzalezJ,EspinosaL,BigasA:
beta-CateninisrequiredforT-cellleukemiainitiationandMYC transcriptiondownstreamofNotch1.Leukemia2016,30:2002- 2010.
39. PuenteXS,PinyolM,QuesadaV,CondeL,OrdonezGR, VillamorN,EscaramisG,JaresP,BeaS,Gonzalez-DiazMetal.:
Whole-genomesequencingidentifiesrecurrentmutationsin chroniclymphocyticleukaemia.Nature2011,475:101-105.
40. KarubeK,EnjuanesA,DlouhyI,JaresP,Martin-GarciaD, NadeuF,OrdonezGR,RoviraJ,ClotG,RoyoCetal.:Integrating genomicalterationsindiffuselargeB-celllymphoma identifiesnewrelevantpathwaysandpotentialtherapeutic targets.Leukemia2018,32:675-684.
41. NatsuizakaM,WhelanKA,KagawaS,TanakaK,GirouxV, ChandramouleeswaranPM,LongA,SahuV,DarlingDS,QueJ etal.:InterplaybetweenNotch1andNotch3promotesEMT andtumorinitiationinsquamouscellcarcinoma.NatCommun 2017,8:1758.
42. ChoiD,RamuS,ParkE,JungE,YangS,JungW,ChoiI,LeeS, KimKE,SeongYJetal.:Aberrantactivationofnotchsignaling inhibitsPROX1activitytoenhancethemalignantbehaviorof thyroidcancercells.CancerRes2016,76:582-593.
43. BedogniB,WarnekeJA,NickoloffBJ,GiacciaAJ,PowellMB:
Notch1isaneffectorofAktandhypoxiainmelanoma development.JClinInvest2008,118:3660-3670.
44. GallardoF,SandovalJ,Diaz-LagaresA,GarciaR,D’AltriT, GonzalezJ,AlegreV,ServitjeO,CrujeirasAB,StefanssonOA etal.:Notch1pathwayactivationresultsfromtheepigenetic abrogationofnotch-relatedmicroRNAsinmycosisfungoides.
JInvestDermatol2015,135:3144-3152.
45. ZhengH,BaeY,Kasimir-BauerS,TangR,ChenJ,RenG,YuanM, EspositoM,LiW,WeiYetal.:Therapeuticantibodytargeting tumor-andosteoblasticniche-derivedJagged1sensitizes bonemetastasistochemotherapy.CancerCell2017,32:731- 747e736.
ThisarticledemonstratesthatNotchsignalingisinducedinresponseto chemotherapyinbreastcancerleadingtoenhancemetastaticpotentialof tumorcells,whichisclinicallyrelevant.Importantly,authorsprovidea potentialtreatmentthatpreventsthisdeleteriouseffectsthroughtheuse ofJagged1blockingantibodies.
46. LiuC,LiuL,ChenX,ChengJ,ZhangH,ZhangC,ShanJ,ShenJ, QianC:LSD1stimulatescancer-associatedfibroblaststo
driveNotch3-dependentself-renewaloflivercancerstem-like cells.CancerRes2018,78:938-949.
47. ChoyL,HagenbeekTJ,SolonM,FrenchD,FinkleD,SheltonA, VenookR,BrauerMJ,SiebelCW:ConstitutiveNotch3signaling promotesthegrowthofbasalbreastcancers.CancerRes 2017,77:1439-1452.
48. PekkonenP,AlveS,BalistreriG,GramolelliS,Tatti-BugaevaO, PaateroI,NiiranenO,TuohintoK,PeralaN,TaiwoAetal.:
Lymphaticendotheliumstimulatesmelanomametastasisand invasionviaMMP14-dependentNotch3andbeta1-integrin activation.Elife2018,7.
