ER ER andand PRPR

progesteron

estradiol

EstradiolEstradiol•• In In thethe femalefemale reproductivereproductive system system itit actsactsmostlymostly on on endometriumendometrium..

•• StimulatesStimulates thethe epithelialepithelial cellscells ofof thethe basalbasallayerlayer ofof thethe endometriumendometrium to to proliferateproliferate, , formingforming a a thickthick mucosamucosa as as wellwell as as numerousnumerousendometrialendometrial glandsglands ((proliferativeproliferative phasephase ofofendometrialendometrial cyclecycle, 6, 6--14 14 daysdays).).

•• Increases Increases thethe expressionexpression ofof progesterone progesterone receptors in receptors in endometriumendometrium..

uterusuterus

endometrium

vaginavagina

EstradiolEstradiol•• StimulatesStimulates thethe developmentdevelopment ofof extensiveextensive mucosalmucosalfoldsfolds ofof thethe oviductoviduct as as wellwell as as thethe formationformation ofof ciliaciliaon on thesethese epithelialepithelial cellscells..

•• PromotesPromotes growthgrowth ofof uterusuterus, , vaginavagina, , andand oviductsoviducts,,as as wellwell as as mammarymammary glandsglands..

•• TriggersTriggers estrusestrus inin femalesfemales ofof differentdifferent mammalsmammals ((supportedsupported by progesteron).by progesteron).

oviduct

ahah......

EstradiolEstradiol•• EstradiolEstradiol iincreasesncreases development of secondary sex development of secondary sex characteristicscharacteristics: : promotespromotes growthgrowth ofof widerwider pelvicpelvic bonesbones as as wellwell as as thethe closureclosure ofof epiphysalepiphysal platesplates inin longlong bonesbones. . HoweverHowever manymany ofof femalefemale secondarysecondary sex sex characteristicscharacteristics areareduedue to to thethe absenceabsence ofof androgensandrogens. .

•• AllowsAllows developmentdevelopment ofof softersofter skin skin andand promotespromotesdepositiondeposition ofof fatfat inin subcatenoussubcatenous zoneszones, , particularlyparticularly ininbreastbreast andand buttocksbuttocks, , leadingleading to to maturemature femalefemale shapeshape..

•• EstradiolEstradiol enhancesenhances calciumcalcium depositiondeposition inin bonebone andandstimulatesstimulates bonebone growthgrowth..

•• Functions as a Functions as a neuroprotectantneuroprotectant andand cardioprotectantcardioprotectant..

SitesSites ofof estrogensestrogens synthesis

-- BeforeBefore menopausemenopause estrogensestrogens areare producedproduced by by enzymeenzyme aromatasearomatase mostlymostly inin::** ovaryovary ((grangranulosaulosa cellscells) )

andand inin otherother tissuestissues, , suchsuch as:as:** subcatenoussubcatenous adipocytesadipocytes ((especiallyespecially estradiolestradiol))* stroma * stroma cellscells inin breastbreast ((especiallyespecially estroneestrone))* * osteocytesosteocytes ((especiallyespecially estroneestrone))* * placentaplacenta ((especiallyespecially estriolestriol))

-- AfterAfter menopausemenopause estrogensestrogens areare not not producedproduced by by ovaryovary but but aromatasearomatase isis stillstill activeactive ininotherother tissuestissues..

synthesis

aromatasearomatasetestosterone estradiol

ProgesteroneProgesterone

•• IsIs involvedinvolved inin maintenancemaintenance ofof pregnancypregnancy..

•• Progesteron Progesteron isis absentabsent inin thethe bloodblood duringduring thethe follicularfollicularphasephase andand appearsappears onlyonly afterafter ovulationovulation..

•• In In thethe femalefemale reproductivereproductive system system itit actsacts mostlymostly on on thethe glandsglands on on thethe endometriumendometrium to to promotepromote theirtheir secretorysecretory activityactivity ((secretorysecretory phasephase ofofendometrialendometrial cyclecycle) ) andand prepareprepare endometriumendometrium for for pregnancypregnancy..

•• ProducedProduced by by thethe ovariesovaries andand placentaplacenta (i(in n nonpregnantnonpregnant womenwomen–– inin corpuscorpus luteumluteum))

ProgesteroneProgesterone duringduring thethe pregnancypregnancy::

•• Increases mammary gland alveolarIncreases mammary gland alveolar--lobular formationlobular formation andand growthgrowth ofof breastbreast. .

•• IInhibitnhibitss new follicular developmentnew follicular development..

•• ActivatesActivates thethe endometrialendometrial glandgland to to secrete fluidssecrete fluids..

•• Maintains the functions of the placenta. Maintains the functions of the placenta.

•• Keeps the Keeps the endometriumendometrium in a thickened conditionin a thickened condition..

•• Stops the uterus Stops the uterus contractionscontractions..

•• Prevents lactation until after the birth (with estrogen) Prevents lactation until after the birth (with estrogen)

•• StrengthensStrengthens the mucus plug covering the cervix the mucus plug covering the cervix

to prevent infection. to prevent infection.

•• Strengthens the pelvic walls in preparation for Strengthens the pelvic walls in preparation for labourlabour. .

At the end of the pregnancyAt the end of the pregnancy, the levels of progesterone secreted by the placenta drop , the levels of progesterone secreted by the placenta drop off.off. It is this action that stimulates the beginning of the contractIt is this action that stimulates the beginning of the contractions that will lead to ions that will lead to birth.birth.

Human Progesterone Receptor: Human Progesterone Receptor: A and B FormsA and B Forms

hPR-B

hPR-A

AF-3 AF-1 AF-2DBD HBD

AF-1 AF-2DBD HBD

•• From single gene by alternate transcriptionFrom single gene by alternate transcription initiation (different promoters)initiation (different promoters)..•• IsoformsIsoforms ddifferiffers s inin activitiesactivities..•• In In humanshumans PRA PRA actsacts as a as a repressorrepressor ofof activityactivity ofof PRB, GR, ER, PRB, GR, ER,

AR, AR, andand MR.MR.•• PRB PRB isis highlyhighly expressedexpressed inin endometriumendometrium duringduring proliferativeproliferativephasephase, but not , but not duringduring thethe secretorysecretory phasephase..

LigandsLigands for Progesterone Receptorfor Progesterone Receptor

O

H3C O

O

H3CO

O

O

H

O

H3C O

O

OHCH3

N CH3H3C

O

OH

NCH3H3C

Et

Et

Et

OAc

CH3

OH

Progestins Antiprogestins

R5020(Promegestone)

ORG2058

Progesterone[natural]

RU486 (Mifepristone)

ZK98299(Onapristone)

Medroxyprogesterone Acetate (MPA)

[HRT]

O

OH

HH

Norethindrone[oral contraceptives]

RU 486 RU 486 –– PR PR antagonistantagonistBBindind to progesterone receptor 3 times more strongly than progesteronto progesterone receptor 3 times more strongly than progesteronee

RU 486 actionRU 486 action1) initiates breakdown of 1) initiates breakdown of endometriumendometrium -- prevents embryo implantation prevents embryo implantation 2) promotes contraction of uterine wall and dilation of cervix, 2) promotes contraction of uterine wall and dilation of cervix, increased sensitivity to increased sensitivity to

PGFPGF22αα -- expulsion of embryo (early pregnancy termination)expulsion of embryo (early pregnancy termination)

Note: Mifepristone = RU486

”morning-after”

Early pregnancytermination

(chorionic gonadotropin)

Estrogen Estrogen receptorsreceptors ((ERsERs):):* * ERERss areare localizedlocalized inin cellcell nucleusnucleus andand areare boundbound to to heatheat shockshock proteinsproteins. . AfterAfter ligandligandbindingbinding theythey form form homodimerhomodimer andand bindbind to consensus to consensus sequencessequences inin thethe promoterspromoters ofof targettargetgenesgenes..

* * ERERss afterafter bindingbinding to consensus to consensus sequencesequence areareubiquitinatedubiquitinated.. PossiblyPossibly ER ER transdicestransdices signalsignalonlyonly onceonce andand thenthen isis degradeddegradedby by proteasomesproteasomes..

* * ThereThere areare twotwo typestypes ofof ER, ER, encodedencoded by by differentdifferent genesgenes: : ERERαα andand ERERββ..

* * BothBoth typestypes havehave severalseveral isoformsisoforms..

EstrogenEstrogen

Cell membraneCell membrane

NucleusNucleus

+ or + or -- GeneGeneexpressionexpression

ActivationActivation ofof ER:ER:

* * ClassicalClassical wayway ofof ER ER activationactivation isis bindingbinding ofof ligandligand (e.g. (e.g. estradiolestradiol).).

* * ER ER maymay be be activatedactivated withoutwithout bindingbinding thethe ligandsligands e.g. As a e.g. As a resultresult ofofphosphorylationphosphorylation.. ER ER cancan be be phosphorylatedphosphorylated e.g. by e.g. by PKAPKA (protein (protein kinasekinase--AA)), PKC, PKC (protein (protein kinasekinase--CC), ), cyclinecycline--dependentdependent kinaseskinases, MAP , MAP kinaseskinases.. PhosphorlationPhosphorlation cancan taketake place place bothboth atat AFAF--1 1 andand AFAF--2.2.

* * PhosphorylationPhosphorylation maymay influence influence thethe ligandligand bindingbinding, , dimerizationdimerization, , bindingbinding to DNA to DNA andand interactioninteraction withwith coco--factorsfactors.. PossiblyPossibly, , eveneven ififphosphorylationphosphorylation maymay occuroccur withoutwithout ligandligand bindingbinding, , thethe bindingbinding ofofligandligand increasesincreases itit. .

Influence Influence ofof ER on ER on genegene transcriptiontranscription::ER ER maymay affectaffect genegene transcriptiontranscription by:by:

* * DirectDirect bindingbinding to consensus to consensus sequencesequence

* * Influence on Influence on NFNFκκBB ((formationformation ofof complexcomplex withwith cc--relrel subunitsubunit) ) –– itit inhibitsinhibits activityactivity ofofNFNFκκBB. . ThereforeTherefore, , estrogensestrogens maymay havehave antiinflammatoryantiinflammatory activityactivity, , inhibitinginhibiting e.g. ILe.g. IL--6, 6, ILIL--11ββ, , TNFTNFαα, M, M--CSF .CSF .

* * Influence on Influence on Sp1Sp1 ((formationformation withwith complexcomplex withwith Sp1) Sp1) –– increasesincreases activityactivity ofof Sp1Sp1,,leadingleading e.g. To e.g. To inductioninduction ofof RARRARαα expressionexpression..

* Influence on * Influence on APAP--11 ((throughthrough interactioninteraction withwith p160 p160 coactivatorscoactivators) ) –– usuallyusually increasesincreasesactivityactivity ofof APAP--1, 1, but but itit maymay dependdepend on on typetype ofof ER ER receptorsreceptors andand typetype ofof ligandligand..

* * Influence on Influence on AREARE ((antioxidantantioxidant responseresponse element) element) –– inin most most casescases itit maymay increaseincrease thetheactivityactivity ofof promoterspromoters ofof genesgenes involvedinvolved inin protectionprotection againstagainst oxidativeoxidative stressstress..

Influence Influence ofof ER on ER on genegene transcriptiontranscription::

ARE - mode

Human Estrogen Receptors Human Estrogen Receptors αα and and ββ

•• DDifferentifferent tissuetissue//cellcell distributionsdistributions

•• DDifferentifferent affinityaffinity for for ligandsligands (?)(?)

•• DDifferentifferent genegene activationsactivations (?)(?)

1 144 227 255NN--

504 530--CCEERRββ

1 180 263 302NN--

552 595--CCEERRαα

AFAF--11 DNADNA LigandLigand / / AFAF--22A/BA/B CC DD EE FF

1188%% 9797%% 3300%% 5959%% 1818%%

-- ERERαα isis much much betterbetter characterizedcharacterized. Role . Role ofof ERERββ isisnot not fullyfully recognizedrecognized..

-- ERERββ isis stronglystrongly expressedexpressed inin malemale reproductivereproductive systemsystem..

-- ERERαα andand ERERββ havehave thethe same same ((identidenticalical PP--boxbox), ), thusthus theythey bindbind to to thethe same consensus same consensus sequencesequence

-- ER ER form form homodimershomodimers, , bothboth ERERαα//ERERαα oror ERERαα//ERERββ..

-- ThereThere areare no no drugsdrugs whichwhich actact as a as a selectiveselective ligendsligends for one for one typetype ofof ER receptorER receptor. . ThereThereareare, , howeverhowever, , somesome compoundscompounds whichwhich bindbind withwith much much higherhigher affinityaffinity (120x) (120x) withwith one one ofofthemthem andand suchsuch whichwhich areare agonistagonist ofof one receptor one receptor andand antagonistantagonist ofof thethe secondsecond receptor.receptor.

-- AF1 AF1 isis veryvery activaactiva inin ERERαα but not but not inin ERERββ.

ERERαα andand ERERββ::

.

ER ER inin malemale reproductivereproductivesystemsystem

-- In In testestestes bothboth receptorsreceptors ((ERERαα andand ERERββ) ) areareexpressedexpressed, but , but theirtheir localizationlocalization isis differentdifferent::

* * ERERαα isis presentpresent inin LeydigLeydig cellscells, , * * ERERββ isis presentpresent inin spermatocytespermatocyte lineagelineage, , SSartoliartoli cellscells andand LeydigLeydig cellscells ((data data fromfrom ratsrats).).

-- LackLack ofof estrogen estrogen synthesissynthesis oror lacklack ofof ER ER ininmalesmales leadsleads to to disturbancesdisturbances inin functionsfunctions ofofreproductivereproductive system.system.

ItIt repeatsrepeats regularlyregularly

andand finallyfinally stopsstops

MenopauseMenopause•• MenopauseMenopause ((cessationcessation ofof ovulationovulation) ) isis uniqueunique to to humanhuman..

•• FemalesFemales ofof otherother speciesspecies show a show a declinedecline inin but not but not completecomplete terminationtermination ofof reproductivereproductivefunctionsfunctions..

•• MenopauseMenopause occursoccurs usuallyusually betweenbetween thethe agesages ofof 4848--52. 52. ThisThis hashas not not changedchanged considerablyconsiderablythroughoutthroughout historyhistory, , althoughalthough menarchemenarche occursoccurs atat yangeryanger agesages todaytoday thanthan 100 100 yearsyears ago ago andand lifelife expectancyexpectancy hashas increasedincreased..

•• MenopauseMenopause isis associatedassociated withwith decreasedecrease inin estradiolestradiol productionproduction andand inin consequencyconsequency ananelevationelevation inin plasmaplasma gonadotropingonadotropin levelslevels. . ItIt stimulatesstimulates ovarianovarian stroma stroma cellscells to to continuecontinueproducingproducing androstenedioneandrostenedione. .

•• EstroneEstrone, , derivedderived almostalmost entirelyentirely fromfrom peripheralperipheral conversionconversion ofof adrenaladrenal andand ovarianovarianandrostenedionandrostenedion, , becomesbecomes thethe dominant estrogen.dominant estrogen.

•• BecauseBecause thethe ratioratio ofof estrogensestrogens to to androgensandrogens decreasesdecreases, , somesome womenwomen havehave hirsuitismhirsuitism duedueto androgen to androgen accessaccess (e.g. (e.g. muostachemuostache...)....).

HormonalHormonal changeschanges duringduring menopausemenopause

0

10

20

30

40

50

60 EstroneEstronepgpg

/ml

/ml

earlyearly latelatefollicularfollicular phasephase

postmenopausalpostmenopausal0

10

20

30

40

50

60

70 EstradiolEstradiol

pgpg/m

l/m

l

earlyearly latelatefollicularfollicular phasephase

postmenopausalpostmenopausal

0

200

400

600

800

1000

1200

1400

1600

1800 AndrostenedioneAndrostenedione

pgpg/m

l/m

l

earlyearly latelatefollicularfollicular phasephase

postmenopausalpostmenopausal0

50

100

150

200

250

300 TestosteroneTestosterone

pgpg/m

l/m

l

earlyearly latelatefollicularfollicular phasephase

postmenopausalpostmenopausal

Osteoporosis

OsteoporoOsteoporosissis-- One One ofof thethe most most frequentfrequent chronicchronic diseasesdiseases. 80% . 80% ofof patientspatients areare womenwomen. . In USA 50% In USA 50% ofofwomenwomen olderolder thanthan 50 50 havehave a a fracturefracture becausebecause ofof osteoporosisosteoporosis..

-- DevelopsDevelops bothboth inin malemale andand femalefemale, but , but inin malemale thisthis processprocess isis slowerslower (as (as theythey havehave moremoredensedense bonesbones, , smallersmaller dicreasedicrease inin sex sex hormoneshormones andand areare moremore activeactive)). .

-- InIn USA USA ~~90% 90% fracturesfractures ((hiphip andand backbonebackbone)) inin oldold womenwomen andand 70% 70% inin oldold menmen resultsresultsfromfrom osteoporosisosteoporosis..

BoneBone densitydensity ((hiphip)) inin womenwomen olderolder thanthan 6565::>833 mg/cm>833 mg/cm22 -- normnorm -- 0%0%833833--648 mg/cm648 mg/cm22 -- osteopeniaosteopenia -- 40%40%<648 mg/cm<648 mg/cm22 -- osteoporoosteoporosissis -- 13%13% (i(in n olderolder thanthan > 80 lat > 80 lat -- 27%)27%)<648 mg/cm<648 mg/cm22 andand fracturesfractures –– strongstrong osteoporosisosteoporosis -- 7%, 7%, (i(in n olderolder thanthan 80 80 -- 27%)27%)

-- SimilaritySimilarity inin bonebone densitydensity isis higherhigher inin monozygoticmonozygotic thanthan inin dizygoticdizygotic twinstwins. . ThusThus therethere isisa a significantsignificant influence influence ofof geneticgenetic factor(sfactor(s) ) controllingcontrolling bonebone metabolismmetabolism..

J. Z. Ilich, and J. E. Kerstetter, Nutrition in Bone Health Revisited: A Story Beyond Calcium. J. Am. Col. Nutr. Vol. 19, No. 6, 715-737 (2000).

OsteoporoOsteoporosissis-- HiherHiher riskrisk ofof osteoporosisosteoporosis isis noticednoticed inin womenwomen withwith familialfamilial historyhistory ofof osteoporosisosteoporosis. . FrequencyFrequency ofof osteoporosisosteoporosis isis increasedincreased by:by:

** inactivainactiva lifelife stylestyle, , * * lowlow calciumcalcium diet (diet (especiallyespecially duringduring maturitionmaturition),),** highhigh alcoholalcohol intakeintake,,* * slimnessslimness

-- RiskRisk isis increasedincreased inin patientspatients treatedtreated withwith corticosteroidscorticosteroids andand thyroidthyroid hormoneshormones..

NormalNormal trabeculartrabecular bonebone OsteoporoticOsteoporotic bonebone

OsteoporoOsteoporosissis-- FracturesFractures areare usuallyusually a a consequencesconsequences ofof a a fallfall, but , but sometimessometimes theythey occuroccur spontaneouslyspontaneously((~~ 5%).5%).

-- TheyThey cancan concernconcern allall bonesbones, but , but usuallyusually theythey occuroccur inin::* * backbonesbackbones, , * * upperupper partpart ofof femurfemur ((andand hiphip))* * wristwrist (as a (as a consequenceconsequence ofof fallfall))

-- FracturesFractures inin backbonesbackbones areare painfulpainful, , but (as but (as oftenoften theythey do not do not resultresult fromfrom strongstrong trauma) trauma) areare oftenoften ignoredignored. . TheyThey areare alsoalso commonlycommonly diagnoseddiagnosed as as osteoarthritisosteoarthritis. . UsuallyUsually theythey arearerecognizedrecognized duringduring routineroutine XX--rayray ofof lungslungs. .

-- IfIf therethere areare severalseveral fracturesfractures, , theythey maymay leadlead to to kypkyphosishosis (”(”widowwidow humphump”), ”), resultingresulting inindisturbeddisturbed functionsfunctions ofof lungslungs andand heartheart andand difficultiesdifficulties inin deeperdeeper breathingbreathing..

kyphosisModel Model ofof vertebraevertebrae

University of Arizona Extension Center

a a normalnormal bonebone; ;

a a bonebone affectedaffected by by osteopeniaosteopenia showingshowing thethebeginningbeginning ofof a a lacklack ofofcalciumcalcium andand lowlow bonebonedensitydensity, ,

a a bonebone showingshowing a a severeseverecasecase ofof osteoporosis

kyphosis

osteoporosis

EstrogenEstrogenss andand bonesbones

* * DevelopmentDevelopment ofof bonesbones duringduring maturitionmaturition dependsdepends mostlymostly on on estrogensestrogens bothboth inin malesmalesandand femalesfemales..

* In * In bothboth sexessexes, estrogen , estrogen deficiencydeficiency leadsleads to to osteoporosisosteoporosis: : inin thethe onlyonly knownknown casecase ofofcompletecomplete insensivityinsensivity to to estrogensestrogens ((point point mutationmutation ofof ER receptor ER receptor resultingresulting inin formationformation ofofstopstop--codoncodon) ) thethe illill manman hadhad increasedincreased bonebone metabolismmetabolism,, osteoporosisosteoporosis, , inmatureinmature epiphysalepiphysalplatesplates andand continouscontinous growthgrowth ofof bonesbones alsoalso duringduring adulthoodadulthood. . SimilarSimilar effectseffects areare observedobservedinin menmen withwith unfuctionalunfuctional aromatasearomatase..

* * EstradiolEstradiol increasesincreases proliferaproliferationtion, , migramigrationtion, , maturitionmaturition andand secretorysecretory activityactivity ofof chondrocyteschondrocytes,,leadingleading to to maturitionmaturition ofof epiphysalepiphysal platesplates andandceasesceases thethe growthgrowth ofof longlong bonesbones..

EstrogenEstrogenss aandnd bonesbones

* * PerhapsPerhaps, , inin bonebone cellscells bothboth ERERαα andand ERERββ areare expressedexpressed. . TheThe lelvellelvel ofof expressionexpression isis, , howeverhowever, , relativelyrelatively lowlow..

* * EstrogEstrogensens actact bothboth on on osteoblastsosteoblasts andand osteoclastsosteoclasts.. In In osteoblastsosteoblasts theythey upregulatesupregulates thetheexpressionexpression ofof alalkkalicalic phosphatasephosphatase, , osteoponosteopontintin, , osteoosteocalcincalcin i i osteoneosteonectinctin.. ItIt isis associatedassociatedwithwith increasedincreased cellcell differentiationdifferentiation, , productionproduction ofof extracellularextracellular matrixmatrix, , andand strongerstrongermineralizationmineralization ofof matrixmatrix..

* Estrogen * Estrogen deficiencydeficiency activatesactivates osteoclastsosteoclasts andand decreasesdecreases theirtheir apoptosisapoptosis..

* * PossiblyPossibly, , estrogensestrogens affectaffect bonesbones mostlymostly throughthrough regulationregulation ofof cytokinecytokine andand growthgrowthfactorsfactors expressionsexpressions:: increasedincreased synthesissynthesis ofof IGFIGF--II andand reducedreduced synthesissynthesis ofof ILIL--66,, ILIL--11ββ, , TNFTNFαα, M, M--CSF, CSF, TGFTGFββ..

* * EstrogensEstrogens upregulatedupregulated thethe expressionexpression ofof 11αα--hydroxylase hydroxylase whichwhich producesproduces thethe activeactiveform form ofof vitaminvitamin D.D.

ProgesteronProgesteronee andand bonesbones

* * ProgesteronProgesteronee protectsprotects againstagainst osteoporosisosteoporosis, but , but itsits efficacyefficacy isis lowerlower thanthan thatthat ofof estrogenestrogen..

* * ProgesteroneProgesterone receptorsreceptors areare presentpresent bothboth inin osteoblastsosteoblasts andand osteoclastsosteoclasts..

* * IncreasesIncreases proliferationproliferation andand differentiationdifferentiation ofof osteoblastsosteoblasts inin vitrovitro..

* * ProgesteroneProgesterone increasesincreases expressionexpression ofof 11αα--hydroxylasehydroxylase

SomeSome nuclearnuclear receptorsreceptors ((ERER, AR, , AR, PRPR) ) stimustimu--latelate expressionexpression ofof cyclincyclin D, D, whichwhich activatesactivatesCdk4. Cdk4. ItIt leadsleads to to phosphorylationphosphorylation ofof pRBpRB, , andandincreasesincreases transcriptiontranscription ofof genesgenes increasingincreasingproliferationproliferation..

OthersOthers receptorsreceptors (VDR, RAR) (VDR, RAR) increaseincrease p21 p21 expressionexpression, , thusthus blockblock CdkCdk activityactivity, , whichwhichkeepskeeps cellscells atat G1 G1 phasephase. .

ER ER inin breastbreast* * EstrogensEstrogens areare necessarynecessary for for normalnormal breastbreast developmentdevelopment

* * EpithelialEpithelial cellscells inin breastbreast undergoundergo cycliccyclic phasesphases ofof proliferationproliferation andand involutioninvolution duringduringmenstruationmenstruation cyclecycle –– thisthis processprocess inin regulatedregulated by by estrogensestrogens

BREAST CANCERBREAST CANCER•• One One outout ofof everyevery 12 12 womenwomen will will developdevelop breastbreast cancercancer..

•• BreastBreast cancercancer isis thethe secondsecond leadingleading causecause ofof deathdeath inin womenwomen ((commonestcommonest causecause ofofcancercancer deathdeath inin womenwomen, 6% , 6% ofof allall deathsdeaths))

•• WorldwideWorldwide, 600,000 , 600,000 casescases ofof breastbreast cancercancer areare diagnoseddiagnosed eacheach yearyear

•• In UK In UK therethere areare 24 000 24 000 newnew casescases andand 12 800 12 800 deathsdeaths annuallyannually..

•• AboutAbout 80% 80% ofof invasiveinvasive breastbreast cancercancer occursoccurs inin womenwomen overover ageage 50. 50.

NormalNormal breastbreast tissuetissue TumorTumor--cellcell proliferationproliferation withwith necrosisnecrosis

ClassificationClassification ofof NeoplasiaNeoplasia

BenignBenign tumorstumors::

-- GrowGrow slowlyslowly andand theirtheir growthgrowth remainsremains localizedlocalized..

-- MayMay presspress on on adjacentadjacent tissuetissue but do not but do not invadeinvade, , destroydestroy oror metastasizemetastasize..

-- SimpleSimple excisionexcision isis usuallyusually curativecurative. .

-- RarelyRarely, , theythey proveprove fatalfatal ifif theythey occuroccur inin a a surgicallysurgically inaccessibleinaccessible sitesite ofof thethe body.body.

MalignantMalignant tumorstumors

-- GrowGrow rapidlyrapidly: : theythey directlydirectly invadeinvade andand destroydestroy adjacentadjacent organsorgans..

-- MetastasizeMetastasize i.e. i.e. spreadspread to to otherother partsparts ofof thethe body body usuallyusually via via thethe bloodblood streamstream, , thethelymphaticlymphatic system system oror acrossacross serousserous membranesmembranes ((peritoneumperitoneum, , pleurapleura, , pericardiumpericardium).).

-- MalignantMalignant tumorstumors presentpresent withwith anan organ organ ofof thethe body body maymay be be primaryprimary oror metastaticmetastatic. .

WHO ClassificationWHO Classification ofof breastbreast cancerscancers

•• Epithelial Epithelial

* * DuctalDuctal (85%) (85%) * * Lobular (1%) Lobular (1%) * * Papillary (<5%) Papillary (<5%)

•• Mixed Connective tissue and EpithelialMixed Connective tissue and Epithelial

Most Most symptomaticsymptomaticcancerscancers presentpresent as a as a painlesspainless bbumpump

PPrognosticrognostic factorsfactors inin breastbreast cancercancer

•• AgeAgeoo Younger women have poorer prognosis of equivalent stageYounger women have poorer prognosis of equivalent stage

•• TumourTumour sizesizeoo Diameter of Diameter of tumourtumour correlates directly with survival correlates directly with survival

•• Lymph node statusLymph node statusoo Single best prognostic factor Single best prognostic factor oo Direct correlation between number and level of nodes involved anDirect correlation between number and level of nodes involved and survival d survival

•• Metastases Metastases oo Distant metastases worsen survival Distant metastases worsen survival

tumortumor lymphlymph nodenode

LocallyLocally advancedadvanced breastbreast carcinomacarcinoma

A A tumortumor accompaniedaccompaniedby by ulcerationulceration

LLymphoedemaymphoedema

Estrogen Estrogen synthesissynthesis inin breastbreast cancercancer

-- EstrogenEstrogenss areare producedproduced inin manymany typestypes ofof cancerscancers, , regardlessregardless thethe presencepresence oror absenceabsenceofof ER ER andand PR PR bothboth inin prepre-- andand postmenopausalpostmenopausal womenwomen..

-- Estrogen Estrogen levellevel inin thethe breastbreast tumorstumors inin postmenopausalpostmenopausal womenwomen cancan be ~20be ~20--fold fold higherhigherthanthan inin serumserum..

-- AboutAbout 70% 70% ofof breastbreast cancerscancers havehave receptorsreceptors for for estrogensestrogens andand progesteroneprogesterone. Estrogen . Estrogen isis a major a major mitogenmitogen for for thisthis typetype ofof cancercancer..

-- ThereThere isis a a strongstrong correlationcorrelation betweenbetween thethe levellevel ofof estrogenesestrogenes inin postpost--menopausalmenopausalwomenwomen andand thethe riskrisk ofof breastbreast cancercancer..

Estrogen Effects in Mammary GlandEstrogen Effects in Mammary Glandand Breast Cancerand Breast Cancer

Cell Cycle Regulation --

↑ Proliferation ↓ Apoptosis

BreastBreast cancercancer –– antiestrogenicantiestrogenic therapytherapy-- ItIt was was notifiednotified inin 1896 1896 thatthat ovarectomyovarectomy leadsleads to to significantsignificant decreasedecrease inin breastbreast carcinomacarcinoma((GG.. BeadsonBeadson, Lancet), Lancet)..

-- HoweverHowever, , alreadyalready inin 1900 1900 assessedassessed thatthat ovarectomyovarectomy helpedhelped onlyonly inin 30% 30% ofof casescases, , andandimprovementsimprovements lastedlasted onlyonly for ~2 for ~2 yearsyears. . DespiteDespite thesethese limitationslimitations endocrynicendocrynic therapytherapybecamebecame a standard a standard inin treatmenttreatment ofof breastbreast cancercancer. . ItIt was was surgicalsurgical antiestrogenicantiestrogenic therapytherapy::

* * ovarectomyovarectomy (i(in n premenopausalpremenopausal womenwomen))* * adrenaleadrenalectomyctomy (i(in n postpost--menopausalmenopausal womenwomen))

-- SurgicalSurgical ovarectomyovarectomy hashas beenbeen replacedreplaced by by ovaryovary irradiationirradiation

-- For ~20 For ~20 yearsyears pharmacologicalpharmacological antiestrogenicantiestrogenic therapytherapy isis appliedapplied usingusing::

•• ER ER antagonistsantagonists•• aromatasearomatase inhibitorsinhibitors

AntiestrogenicAntiestrogenic therapytherapy –– selectionselection ofof patientspatients-- ItIt was was foundfound inin 11971 971 thatthat antiestrogenicantiestrogenic therapytherapy isis effectiveeffective inin treatmenttreatment ofof cancerscancers withwith a a highhighlevellevel ofof ER ER expressionexpression ((improvementimprovement was was observedobserved inin 60% 60% ofof patientspatients) )

-- ImmunohistochemistryImmunohistochemistry evidencedevidenced thatthat cellcell inin thethe same same tumortumor maymay havehave differendifferen levellevel ofof ER ER expressionexpression. . ThereforeTherefore, , thethe antiestrogenicantiestrogenic therapytherapy isis less less effectiveeffective inin thethe latelate stagesstages ofof cancercancer((higherhigher diversitydiversity ofof cellscells))..

ERER--positivepositive cancercancer CancerCancer withwith differentdifferent expressionexpression ofof ERER

SERM (SERM (selectiveselective estrogenestrogen--receptor receptor modulatorsmodulators))TamoxifenTamoxifen

-- TamoTamoxxifenifen isis anan antiestrogenantiestrogen,, whichwhich blockblock bindingbinding ofof estrogen to ERestrogen to ER..

-- ItIt was was inventedinvented duringduring studystudy on on contraceptivecontraceptive pillspills inin 1960’s.1960’s.

-- In 1970’s In 1970’s elaboratedelaborated laboratorylaboratory strategiesstrategies ofof breastbreast cancercancer preventionprevention usingusing tamoxifentamoxifen. . HoweverHowever, , itit diddid not not stirstir upup thethe interestinterest ofof cliniciansclinicians, , whowho believedbelieved inin chemotherapychemotherapy..

-- 25 25 yearsyears laterlater tamoxifentamoxifen was was foundfound to be to be effectiveeffective alsoalso inin clinicalclinical practicepractice –– underunderconditioncondition ofof selectionselection ofof appropriateappropriate groupgroup ofof patienspatiens ((cancerscancers withwith highhigh levellevel ofof ER) ER) andandlonglong--termterm applicationapplication ((moremore thanthan 5 5 yearsyears))

-- TamoTamoxxifenifen couldcould be be usefuluseful inin womenwomen atat highhigh riskrisk ofof breastbreast cancercancer..

ComparisonComparison ofof shortshort--termterm andand longlong--termterm treatmenttreatment withwith tamoxifentamoxifen on on thethegrowthgrowth ofof breastbreast cancercancer inin ratsrats

PharmacologicallyPharmacologically inducedinduced cancercancer..TreatmentTreatment withwith tamoxifentamoxifen beganbegan 30 30 daysdays afterafter inductioninduction

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TamoxifenTamoxifen –– clinicalclinical trialstrials

-- MoreMore thanthan 13 000 13 000 womenwomen atat highhigh riskrisk ofof breastbreast cancercancer ((beforebefore andand afterafter menopausemenopause) ) werewere treatedtreated for 5 for 5 yearsyears withwith tamoxifentamoxifen oror placeboplacebo. .

-- TamoTamoxxifenifen decreaseddecreased thethe riskrisk ofof breastbreast cancercancer by by 50%.50%.

ThereThere werewere, , howeverhowever, , seriousserious sideside--effectseffects::

-- TendencyTendency to to increasedincreased bonebone fracturefracture raterate

-- IncreaseIncrease (2.6 (2.6 -- 4 4 foldfold) ) freaquencyfreaquency ofof uterusuterus cancercancer inin postmenopausalpostmenopausal womenwomen..

In In thethe latelate 1980s 1980s itit was was recommendedrecommended as a as a drugdrug protectingprotecting thethe womenwomen withwith a a highhigh riskrisk ofofbreastbreast cancercancer, but not , but not inin generalgeneral populationpopulation becausebecause ofof thethe riskrisk ofof cervicalcervical cancercancer..

TamoxifenTamoxifen –– clinicalclinical trialstrials

-- TamoxifenTamoxifen therapytherapy whenwhen startedstarted directlydirectly afterafter surgicalsurgical removalremoval ofof earlyearly stagestage ofofestrogeneestrogene--sensitivesensitive cancercancer ((withwith ER ER expressionexpression) ) decreaseddecreased mortalitymortality afterafter 5 5 yearsyears by by 28%.28%.

-- DuringDuring 1212 yearsyears (1988(1988--2000)2000) afterafter employmentemployment ofof tamoxifentamoxifen inin UK, UK, numbernumber ofof deathsdeathscausedcaused by by breastbreast cancercancer decreaseddecreased fromfrom 16 000 16 000 toto 12 80012 800..

TamoxifenTamoxifen -- characteristicscharacteristics

-- TamoTamoxxifenifen isis usedused as a as a competitivecompetitive antagonistantagonist ofof ER.ER.

-- AfterAfter bindingbinding tamoxifentamoxifen, , ERER maymay dimerizedimerize andand bindbind to consensus to consensus sequencesequence. . ChangedChangedconformationconformation ofof suchsuch a a complexcomplex changeschanges interactioninteraction withwith corepressorscorepressors andand coactivatorscoactivators, , whenwhen comparedcompared withwith estrogenestrogen--ligatedligated receptor.receptor.

-- EffectsEffects ofof tamoxifentamoxifen cancan be be tissuetissue--specificspecific. In . In somesome tissuestissues ((uterusuterus) ) thethe drugdrug behavesbehaves as as partialpartial agonistagonist. . ThereforeTherefore itsits effectivityeffectivity isis limitedlimited..

-- TamoTamoxifenxifen doesdoes not not decreasedecrease thethe expressionexpression ofof PR (PR (andand eveneven cancan increaseincrease itit)). . ProgesteronProgesterone e isis a a mitogenmitogen for for breastbreast cancercancer cellscells..

-- PatientsPatients sufferingsuffering fromfrom cancercancer lackinglacking ER do not ER do not respondrespond to to treatmenttreatment withwith tamoxifentamoxifen. .

-- ManyMany cancerscancers afterafter temporarytemporary improvementimprovement acquireacquire resistancyresistancy to to tamoxifentamoxifen andand startsstarts to to growthgrowth againagain. .

Tissue SelectivityTissue Selectivity

•• AntagonistAntagonist -- bbreastreast, , uuterusterus

•• AgonistAgonist -- bbone, one, bbrain, rain, ccolonolon,, neuronsneurons, , bloodblood vesselsvessels

-- Ideal Profile for Ideal Profile for SERMSERM

SERM (SERM (selectiveselective estrogenestrogen--receptor receptor modulatorsmodulators))

RaloxifenRaloxifen

-- DrugDrug similarsimilar to to tamoxifentamoxifen, but , but withwith weakerweaker proestrogenicproestrogenic activityactivity inin thethe uterusuterus. .

-- MaintainsMaintains appropriateappropriate bonebone densitydensity inin thethe postmenopausalpostmenopausal womenwomen, , andand inin thethe same same timetime decreasesdecreases riskrisk ofof breastbreast cancercancer..

-- OngoingOngoing clinicalclinical trialtrial (to be (to be finishedfinished inin 2005) 2005) isis designeddesignedto test to test itsits effectivityeffectivity inin preventionprevention ofof ischemicischemic heartheartdiseasedisease inin postmenopausalpostmenopausal womenwomen. .

WhyWhy doesdoes tamoxifentamoxifen actact as as proestrogenproestrogen inin uterusuterus, , whilewhile raloxifenraloxifen notnot??

-- SideSide chainchain ofof raloxifenraloxifen isis locatedlocated 1 1 ÅÅ closercloser toto asparticaspartic acidacid 351351 thanthan sideside chainchain ofoftamoxifentamoxifen. .

-- RaloxifenRaloxifen affectsaffects not not onlyonly AF2 AF2 inin LBD, but LBD, but alsoalso AF1 AF1 ofof A/B region A/B region andand blocksblocks itsitsactivationactivation. In . In thethe casecase ofof tamoxifentamoxifen, , transactivationtransactivation throughthrough AF1 AF1 isis possiblepossible. .

-- IfIf ER ER undergoesundergoes thethe mutamutationtion (D351Y), (D351Y), whatwhat happenshappens inin somesome cancerscancers, , raloxifenraloxifen startsstartsto to actact as estrogen.as estrogen.

tamoksifenraloksifen

AromataAromatasese-- AromataAromatasese ((microsomalmicrosomal cytochromecytochrome P450P450) ) isis anan enzymeenzyme transformingtransforming androgensandrogens to to estrogensestrogens ((testosterontestosterone toe to estradiolestradiol, , androstenedionandrostenedionee do do estronestronee) )

-- ItIt isis thethe onlyonly sourcesource ofof steroid estrogen.steroid estrogen.

AromataAromatasese

-- AromataseAromatase genegene (CYP19) (CYP19) isis locatedlocated atat chromosome 15chromosome 15 andand hashas 99 eexonsxons. .

-- In In humanhuman populationpopulation aromatasearomatase isis polymorphicpolymorphic andand itit maymay influence on influence on thethe estrogen estrogen levellevel inin womenwomen..

-- IncreasedIncreased expressionexpression ofof aromatasearomatase inin cancerscancers, , resultsresults fromfrom usageusage ofof differentdifferent promoterpromoter((insteadinstead ofof promoterpromoter whichwhich isis normallynormally activeactive inin adipocytesadipocytes, , activeactive becomesbecomes promoterpromoternormallyactivenormallyactive inin thethe ovaryovary).).

-- UpregulationUpregulation ofof aromatasearomatase synthesissynthesis cancan be be inducedinduced by prostaglandinby prostaglandin--E2 (via E2 (via cAMPcAMP).).MaybeMaybe for for itsits inhibitioninhibition COXCOX--2 2 inhibitorsinhibitors couldcould be be usedused..

-- TissueTissue--specificspecific regulationregulation ofof aromatasearomatase genegene expressionexpression suggestssuggests thethe possibilitypossibility to to findfinda a tissuetissue--specificspecific inhibitor.inhibitor.

AAromataromatasese inhibitorsinhibitors--AromataseAromatase inhibitorsinhibitors maymay be steroid be steroid oror nonnon--steroidsteroid compoundscompounds. .

* * Steroid Steroid inhibitorsinhibitors ((e.g.e.g. exemestaneexemestane) ) areare derivetivesderivetives ofof androstenedionandrostenedionee((aromatasearomatase substratesubstrate) ) andand actact as as competitvecompetitve inhibitorsinhibitors. .

* * NonNon--steroidsteroid inhibitorsinhibitors ((npnp. . letrozoleletrozole) ) bindbind throughthrough nitrogennitrogen atom to atom to ironiron atom atom inin hemeheme groupgroup inin aromatasearomatase..

-- TheThe idealideal aimaim wouldwould be be completecomplete inhibitioninhibition ofof estrogensestrogens, but , but withoutwithout sideside effectseffects. . UnfortunatelyUnfortunately, , firstfirst drugsdrugs werewere not not fullyfully specificspecific andand becausebecause ofof sideside effectseffects couldcould not be not be usedused inin a a fullyfully efficientefficient dosesdoses..

-- ManyMany aromatasearomatase inhibitorsinhibitors ((drugsdrugs ofof thethe I I andand II II generationsgenerations) ) introducedintroduced to to thethe market market atat thethe beginningbeginning 19199090s s havehave beenbeen withdrownwithdrown..

-- DrugsDrugs ofof thethe thirdthird generationgeneration ((e.g. e.g. letrozolletrozolee)) cancan be be appliedapplied inin dosesdoses whichwhich ininpostmenopausalpostmenopausal womenwomen almostalmost completelycompletely inhibitinhibit aromatasearomatase (99%)(99%) andand do not do not produceproducesideside effectseffects apartapart ofof thosethose resultingresulting fromfrom inhibitioninhibition ofof hormonehormone synthesissynthesis..

AromataseAromatase inhibitorsinhibitors –– clinicalclinical applicationsapplications

-- AromataseAromatase inhibitorsinhibitors decreasedecrease proliferationproliferation ofof thethe brestbrest cancercancer cellscells inin thethe higherhigher extentextentthanthan tamoxifentamoxifen. .

-- TheyThey cancan be be usedused onlyonly inin postpost--menopausalmenopausal womenwomen, , oror inin premonopausalpremonopausal patientpatient subjectedsubjectedto to ovarectomyovarectomy –– inin premenopausalpremenopausal womenwomen theythey produceproduce onlyonly partialpartial inhibitioninhibition ofof estrogeneestrogeneproductionproduction..

-- In In thethe midmid 1990s 1990s inhibitorsinhibitors ofof III III generationgeneration havehave beenbeen intoducedintoduced ((anastrozolanastrozolee, , letrozolletrozolee, , exemestanexemestanee). ).

-- TrialsTrials enrolingenroling moremore thanthan 2000 2000 womenwomen havehave evidencedevidenced thatthat theythey areare much much moremore effectveeffectvethanthan ER ER antagonistsantagonists ((e.g.e.g. tamoxifentamoxifen) ) andand thanthan aromatasearomatase inhibitorsinhibitors ofof earlierearlier generationsgenerations. .

AromataseAromatase inhibitorsinhibitors –– clinicalclinical applicationsapplicationsATACATAC trialtrial ((anastrozoleanastrozole, , tamoxifentamoxifen, or combination , or combination tamoxifentamoxifen and and anastrozoleanastrozole))

-- 9366 9366 postmenopausalpostmenopausal patientspatients, , withwith earlyearly breastbreast cancercancer werewere divideddivided to 3 to 3 groupsgroups: :

a) a) tamotamoksksiiffenen ((antagonistantagonist ofof ER)ER), , b) b) anastanastrrozoleozole ((aromatazearomataze inhibitor)inhibitor)c) c) combinationcombination ofof bothboth drugsdrugs

-- comparingcomparing to to tamoxifentamoxifen, afer , afer 3333 monthsmonths inin patientspatients treatedtreated withwith anastrozolemanastrozolem was was demonstrateddemonstrated::

* much * much higherhigher proportionproportion ofof patientspatients freefree ofof diseasedisease* * significantlysignificantly less less casescases ofof developmentdevelopment ofof newnew cancercancer inin thethe secondsecond breastbreast* less * less significantsignificant sideside--effectseffects, , althoughalthough higherhigher fracturefracture raterate andand higherhigher levellevel ofof

bonebone resorptionresorption markersmarkers thanthan inin generalgeneral populationpopulation

-- combinationcombination ofof bothboth drugsdrugs was less was less effectiveeffective thanthan anastrozolanastrozol alonealone..

AromataseAromatase inhibitorsinhibitors –– clinicalclinical trialstrials

-- PostPost--menopausalmenopausal patientspatients, , withwith largelarge (>3 cm)(>3 cm) breastbreast cancercancer werewere divideddivided intointo twotwogroupsgroups treatedtreated withwith: :

* * tamoxifenetamoxifene (ER (ER antagonistantagonist))* * letrozoleletrozole ((aromatasearomatase inhibitor)inhibitor)

-- TumorsTumors werewere removedremoved surgicallysurgically, but , but earlierearlier patientspatients werewere treatedtreated withwith one one ofof thethedrugsdrugs to to induceinduce reductionreduction ofof tumortumor andand facilitatefacilitate romovalromoval ofof tumortumor withwith minimalminimaldestroydestroy ofof healthyhealthy breastbreast tissuetissue. .

-- AromataseAromatase inihibitorinihibitor was was moremore effectiveeffective (55% (55% versusversus 36% 36% tumorstumors, , whosewhose growthgrowthdecreaseddecreased by 50%by 50%))..

ThankThank youyou andand seesee youyou nextnext weekweek......

WhatWhat wouldwould be be profitableprofitable to to rememberremember inin JuneJune::

-- StructureStructure andand isoformsisoforms ofof ER ER andand PRPR

-- Role Role ofof ER ER inin osteoporosisosteoporosis

-- ER inhibitor ER inhibitor andand aromatasearomatase inhibitorsinhibitors inin treatmenttreatmentofof breastbreast cancercancer

SSlideslides cancan be be foundfound inin thethe librarylibrary andand atat thetheHemeHeme OxygenaseOxygenase Fan Fan ClubClub pagepage::

https://https://biotka.mol.uj.edu.pl/~hemeoxygenasebiotka.mol.uj.edu.pl/~hemeoxygenase