hERG1channels:froman2targetstonoveltherapeu2ctargetsinoncology

AnnarosaArcangeli1,AndreaBecche-2,OliviaCrociani,MassimoD’Amico1,LucaGasparoli1,MarikaMasselli,SerenaPillozzi1,KennethMugridge3andWolfgangTiedke3.

1DepartmentofExperimentalPathologyandOncology,UniversityofFlorenceandIsPtutoToscanoTumori(ITT),Florence,Italy;2DepartmentofBiotechnologyandBiosciences,

UniversityofMilanoBicocca,Milano,Italy;3BlackSwanPharmaGmbH,Leipzig,Germany.

Disclosures

•  Noconflictofinteresttodeclare

hERG1POTASSIUMCHANNELS

SeveraldrugsblockhERG1channels

drug‐inducedLQT2

ANTITARGET

SpecifichERG1blockersE4031WAY123,398

‐ AcutemyeloidandlymphoblasPcleukemiasHofmannetal.,J.Biol.Chem.,2001;Pillozzietal.,Leukemia,2002;Pillozzietal.,Blood,2007;Pillozzietal.,Blood,2011

‐ EndometrialCancersCherubinietal.,Br.J.Cancer,2000

‐ NeuroblastomasArcangelietal.,J.CellBiol.,1993;Arcangelietal.,J.Physiol.,1995;Arcangelietal.,Eur.J.Neurosci,1997;Crocianietal.,Mech.Devel.,2000;Crocianietal.,J.Biol.Chem.,2003

‐ ColorectalandGastricCancersLastraiolietal.,CancerRes.2004;Lastraiolietal.,J.Cell.Physiol.,2006.

‐ GlioblastomaMasietal.,Br.J.Cancer,2005.

hERG1isoverexpressedinseveraltypesofhumancancers

hERG1regulatesdifferentbiologicalfunc2onsincancercells

•  Cellprolifera2on(myeloidleukemias)

•  Drug‐inducedapoptosis(lymphoblas2cleukemias)•  Tumorcellinvasionandmetasta2cspread(colorectalcancers)

•  Trans‐endothelialmigra2onandinvasionofextra‐medullaryorgans(myeloidleukemias)

•  VEGF‐Asecre2onandangiogenesis(astrocytomas;gastricandcolorectalcancers)

hERG1:

newtargetinoncology?

Adversecardiaceffects!

Differencesbetween“cardiac”and“tumour”hERG1

•  Biophysical•  Molecular

•  FuncPons

BiophysicalcharacterisPcsofhERG1channels

I(K)ERGquicklyinac2vatesaferopeningatposi2vepoten2alsInac2va2onisfasterthanac2va2onRecoveryfrominac2va2onisfasterthandeac2va2on

Membranepoten2al

• Intheheart:hERG1=Ikr• hERG1channelsac2vateslowlyandinac2vaterapidlyduringtheini2alphasesofthecAP;asrepolariza2onbegins,hERG1channelsrapidlyrecoverfrominac2va2onandgenerateanappreciableoutwardcurrent.• Incancercells:• hERG1channelsexibitasignificantsteady–stateconductanceatmembranepoten2alsaround‐40mV

Molecularcharacteris2csofhERG1incancercells

A

Func2onsofhERG1incancercells

hERG1channelsco‐assemblewithintegrinsandmodulateintegrin‐dependentsignalling.

PotenPalapproachestoimprovetheefficacyandsafetyofhERG1channel

targePnginoncology:

‐Useof“non‐torsadogenic”hERG1blockers(e.g.erythromycin,ser2ndole).‐ UseofcompoundswhichbindhERG1channelsintheopenstate(D‐Roscovi2ne).‐ Use/developmentofcompoundswhichselec2velyinhibittumour‐specifichERG1isoform(s)‐Developmentofcompounds(an2bodies,pep2des)whichdisassembletheionchannel/integrincomplex.

PotenPalapproachestoimprovetheefficacyandsafetyofhERG1channel

targePnginoncology:

‐Useof“non‐torsadogenic”hERG1blockers(e.g.erythromycin,ser2ndole).‐ UseofcompoundswhichbindhERG1channelsintheopenstate(D‐Roscovi2ne).‐ Use/developmentofcompoundswhichselec2velyinhibittumour‐specifichERG1isoform(s)‐Developmentofcompounds(an2bodies,pep2des)whichdisassembletheionchannel/integrincomplex.

ErythromycinSer2ndole

State‐dependentblockofHERGpotassiumchannelsbyR‐roscovi)ne:

implicaPonsforcancertherapy

GanapathiSBetal.,AmJPhysiolCellPhysiol296:C701–C710,2009.

R‐RoscoviPne

SerenaPillozzi

SURVIVAL (ILK, AKT)

β1/hERG1/CXCR4 complex

Thecomplexisrelevanttodrivesurvivalsignals

whichistheeffectofblockinghERG1channelsondrug‐inducedapoptosis?

apop

to2ccells(%

)(Ann

exin+/PI‐)

TheaddiPonofhERG1blockersshortcomestheprotecPveeffectofBoneMarrowStromalCellsonDoxorubicin(Prednisone,Methotrexate,L‐asparaginase)‐induced

apoptosis

PrimaryB‐ALL

E4031synergizeswithchemotherapeu2cdrugs……onMSC

EffectsofthehERG1blockerE4031invivo

E4031hasatherapeu2ceffectinvivoonB‐ALL(697cells):increasein

survival

E4031hasatherapeu2ceffectinvivoonB‐ALL(cor2costeroid‐resistantREH

cells)

NontorsadogenichERG1blockers(ErythromycinandSer2ndole)andR‐

Roscovi2nehavethesameeffectsofE4031

EffectsofErythromycinonprimaryB‐ALL

PotenPalapproachestoimprovetheefficacyandsafetyofhERG1channel

targePnginoncology:

‐Useof“non‐torsadogenic”hERG1blockers(e.g.erythromycin,ser2ndole).‐ UseofcompoundswhichbindhERG1channelsintheopenstate(D‐Roscovi2ne).‐ Use/developmentofcompoundswhichselec2velyinhibittumour‐specifichERG1isoform(s)‐Developmentofcompounds(an2bodies,pep2des)whichdisassembletheionchannel/integrincomplex.

Leipzig,Germany

W.Tiedke

EffectsofCD‐160130onprolifera2onofleukemiacelllinesandhERG1A/hERG1B‐expressingcells:LD50

values(comparisonwithE4031)

MassimoD’AmicoLucaGasparoli

CD‐160130preferen2allyinhibitsthehERG1Bisoform(comparisonwithE4031)

FLG29.1CellsIC501.2µM

CD‐160130preferen2allyblockshERG1Bisoform

…alsoinleukemiacells

CD‐160130issynergicwithFludarabineonapoptosisofMEC1cells(CLL)onMSC

•  LessharmfulcompoundscanbedevelopedwhichblockhERG1

channelsincancercells.

Acknowledgements:

Dr.AndreaBecche-UniversityofMilanoBicocca

Prof.EnzoWanke