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Letrozole Aromatase inhibitor

Cat.nr.: S1235

Letrozole is a third generation inhibitor of aromatase with IC50 of 0.07-20 nM in cell-free assays. It has no effect on the plasma levels of 17α-OH progesterone, thyroid-stimulating hormone (TSH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), or androstenedione and does not affect normal urine electrolyte excretion or thyroid function in clinical studies. This compound induces autophagy.
Letrozole Aromatase inhibitor Chemical Structure

Chemische structuur

Molecuulgewicht: 285.3

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Kwaliteitscontrole (Quality Control)

Batch: Zuiverheid: 99.99%
99.99

Celkweek, behandeling & werkzame concentratie
(Cell Culture, Treatment & Working Concentration)

Cellijnen Assaytype Concentratie Incubatietijd Formulering Activiteitsbeschrijving PMID
JEG3 Function assay Inhibition of aromatase activity in human JEG3 cells, IC50=0.00089μM 18590272
JEG3 Function assay Inhibition of aromatase in human JEG3 cells by scintillation spectrometry, IC50=0.00089μM 20148564
MDA-MB-435 Growth inhibition assay 48 hrs Growth inhibition of human MDA-MB-435 cells after 48 hrs by sulforhodamine B assay, GI50=0.067μM 20950898
IGROV1 Growth inhibition assay 48 hrs Growth inhibition of human IGROV1 cells after 48 hrs by sulforhodamine B assay, GI50=0.095μM 20950898
MDA-MB-231 Growth inhibition assay 48 hrs Growth inhibition of human MDA-MB-231cells after 48 hrs by sulforhodamine B assay, GI50=0.15μM 20950898
T47D Growth inhibition assay 48 hrs Growth inhibition of human T47D cells after 48 hrs by sulforhodamine B assay, GI50=0.44μM 20950898
MCF7 Growth inhibition assay 48 hrs Growth inhibition of human MCF7 cells after 48 hrs by sulforhodamine B assay, GI50=0.7μM 20950898
OVCAR4 Growth inhibition assay 48 hrs Growth inhibition of human OVCAR4 cells after 48 hrs by sulforhodamine B assay, GI50=0.88μM 20950898
BT549 Growth inhibition assay 48 hrs Growth inhibition of human BT549 cells after 48 hrs by sulforhodamine B assay, GI50=0.89μM 20950898
SKOV3 Growth inhibition assay 48 hrs Growth inhibition of human SKOV3 cells after 48 hrs by sulforhodamine B assay, GI50=1.09μM 20950898
NCI/ADR-RES Growth inhibition assay 48 hrs Growth inhibition of human NCI/ADR-RES cells after 48 hrs by sulforhodamine B assay, GI50=1.16μM 20950898
MDA-N Growth inhibition assay 48 hrs Growth inhibition of human MDA-N cells after 48 hrs by sulforhodamine B assay, GI50=1.61μM 20950898
OVCAR5 Growth inhibition assay 48 hrs Growth inhibition of human OVCAR5 cells after 48 hrs by sulforhodamine B assay, GI50=1.62μM 20950898
Hs 578T Growth inhibition assay 48 hrs Growth inhibition of human Hs 578T cells after 48 hrs by sulforhodamine B assay, GI50=2.17μM 20950898
OVCAR8 Growth inhibition assay 48 hrs Growth inhibition of human OVCAR8 cells after 48 hrs by sulforhodamine B assay, GI50=4.5μM 20950898
OVCAR3 Growth inhibition assay 48 hrs Growth inhibition of human OVCAR3 cells after 48 hrs by sulforhodamine B assay, GI50=5.87μM 20950898
MCF7a Cytotoxicity assay 10 days Cytotoxicity against human MCF7a cells expressing Tet-off-3betaHSD1-Arom assessed as inhibition of TST-stimulated cell proliferation measured after 10 days, EC50=0.000004μM 22951074
V79MZh Function assay Inhibition of human CYP11B2 expressed in hamster V79MZh cells using [1,2-3H]-11-deoxy-corticosterone as substrate, IC50=1.42μM 23281812
V79MZh Function assay Inhibition of human CYP11B1 expressed in hamster V79MZh cells using [1,2-3H]-11-deoxy-corticosterone as substrate, IC50=2.62μM 23281812
H295R Function assay 5 uM 24 hrs Inhibition of CYP19 in human H295R cells using [1beta-3H(N)]-androst-4-ene-3,17-dione at 5 uM after 24 hrs by tritiated water release assay 24025069
MCF7 Cytotoxicity assay 72 hrs Cytotoxicity against estrogen-dependent human MCF7 cells after 72 hrs by MTT assay, IC50=0.007μM 24345481
MCF7 Cytotoxicity assay 24 to 96 hrs Cytotoxicity against human MCF7 cells after 24 to 96 hrs, IC50=0.02μM 24345481
JEG-3 Function assay Inhibition of aromatase (unknown origin) expressed in JEG-3 cells, IC50=0.00089μM 25992880
insect cells Function assay 30 mins Inhibition of recombinant human CYP19 expressed in baculovirus infected insect cells using MFC as substrate measured after 30 mins by fluorometric analysis, IC50=0.0053μM 27647367
T47D Function assay 24 hrs Inhibition of aromatase activity in human T47D cells after 24 hrs, IC50=29.5μM 27770735
T47D Function assay 24 hrs Inhibition of aromatase activity in human T47D cells after 24 hrs, IC50=29.5μM 28427017
MCF7 Cytotoxicity assay 48 hrs Cytotoxicity against human MCF7 cells after 48 hrs by MTT assay, IC50=4.73μM 29202405
MCF7 Growth inhibition assay 72 hrs Growth inhibition of human MCF7 cells incubated for 72 hrs by cell counting based method, GI50=4.1μM 30822713
MDA-MB-231 Growth inhibition assay 72 hrs Growth inhibition of human MDA-MB-231 cells incubated for 72 hrs by cell counting based method, GI50=10μM 30822713
insect cells Function assay Inhibition of recombinant human aromatase expressed in baculovirus infected insect cells using O-benzyl fluorescein benzyl ester as substrate in presence of NADPH generating system by fluorescence based analysis, IC50=0.0019μM 31416738
MCF-7aro Function assay 1 hr Inhibition of aromatase in human MCF-7aro cells using [1beta-3H] androstenedione as substrate incubated for 1 hr by liquid scintillation counting method, IC50=0.0019μM 31732252
insect cells Function assay 30 mins Inhibition of human recombinant aromatase expressed in baculovirus infected insect cells using O-benzylfluorescein benzyl ester as substrate after 30 mins, IC50=0.0011μM ChEMBL
Klik om meer experimentele gegevens over cellijnen te bekijken

Chemische informatie, opslag en stabiliteit (Chemical Information, Storage & Stability)

Molecuulgewicht 285.3 Formule

C17H11N5

Opslag (vanaf de datum van ontvangst)
CAS-nr. 112809-51-5 SDF downloaden Opslag van stamoplossingen

Synoniemen CGS 20267 Smiles C1=CC(=CC=C1C#N)C(C2=CC=C(C=C2)C#N)N3C=NC=N3

Oplosbaarheid (Solubility)

In vitro
Batch:

DMSO : 57 mg/mL (199.78 mM)
(Met vocht verontreinigd DMSO kan de oplosbaarheid verminderen. Gebruik verse, watervrije DMSO.)

Water : Insoluble

Ethanol : Insoluble

Molariteitscalculator

Massa Concentratie Volume Molecuulgewicht
Verdunningscalculator Molecuulgewichtcalculator

In vivo
Batch:

In vivo formulatiecalculator (heldere oplossing)

Stap 1: Voer onderstaande informatie in (Aanbevolen: een extra dier om rekening te houden met verlies tijdens het experiment)

mg/kg g μL

Stap 2: Voer de in vivo formulering in (Dit is alleen de calculator, geen formulering. Neem eerst contact met ons op als er geen in vivo formulering is in de sectie oplosbaarheid.)

% DMSO % % Tween 80 % ddH2O
%DMSO %

Berekeningsresultaten:

Werkconcentratie: mg/ml;

Methode voor het bereiden van DMSO-moedervloeistof: mg geneesmiddel vooropgelost in μL DMSO ( Concentratie moedervloeistof mg/mL, Neem eerst contact met ons op als de concentratie de DMSO-oplosbaarheid van de batch van het geneesmiddel overschrijdt. )

Methode voor het bereiden van in vivo formulering: Neem μL DMSO moedervloeistof, voeg daarna toeμL PEG300, mengen en verhelderen, daarna toevoegenμL Tween 80, mengen en verhelderen, daarna toevoegen μL ddH2O, mengen en verhelderen.

Methode voor het bereiden van in vivo formulering: Neem μL DMSO moedervloeistof, voeg daarna toe μL Maïsolie, mengen en verhelderen.

Opmerking: 1. Zorg ervoor dat de vloeistof helder is voordat u het volgende oplosmiddel toevoegt.
2. Zorg ervoor dat u het/de oplosmiddel(en) in de juiste volgorde toevoegt. U moet ervoor zorgen dat de verkregen oplossing, bij de vorige toevoeging, een heldere oplossing is voordat u verdergaat met het toevoegen van het volgende oplosmiddel. Fysieke methoden zoals vortexen, ultrasoon of een warmwaterbad kunnen worden gebruikt om het oplossen te bevorderen.

Werkingsmechanisme (Mechanism of Action)

Targets/IC50/Ki
Aromatase
(Cell-free assay)
0.07 nM-20 nM
In vitro

Letrozole potently inhibits aromatase derived from a variety of different sources including human placental microsomes, particulate fractions of human breast cancer, rat ovarian microsomes, MCF-7 cells transfected with aromatase (MCF-7Ca), JEG-3 human choriocarcinoma cells , CHO cells, hamster ovarian tissue, and particulate fractions of human breast cancer with IC50 of 11, 2, 7, 0.07, 0.07, 1.4, 20 and 0.8 nM. In the non-cellular systems, the IC50 of this compound is calculated to be 1-13 nM. It maximally inhibits estradiol production in vitro in LH-stimulated hamster ovarian tissue at 0.1 μM with an IC50 of 0.02 μM and does not significantly affect progesterone production up to 350 μM. In ACTH-stimulated rat adrenal tissue in vitro, aldosterone production is inhibited by with an IC50 of 210 μM. This chemical inhibits growth of the MCF-7 epithelial breast cancer cells in a dose-dependent way with IC50 of 1 nM. Inhibition can be observesed even at the very low concentrations tested (0.1 nM). Treatment of normal MCF-12A epithelial cells with this compound did not affect their growth even when high letrozole concentrations (100 nM) or prolonged culture times. Concurrent administration of 17-β-estradiol with it (10 nM) decreased the stimulatory effect of the enzymatic activity of MMP-2 and - 9 released by estradiol.

Kinase Assay
Activiteit van humane placentaire aromatase
De test wordt uitgevoerd in een totaal volume van 1 ml bij 37 ℃. Tenzij anders vermeld, bevat het incubatiemengsel 11 nM [4- 14C] androstene-3, 17-dion ([4- 14C]A), 24 mM NADPH (tetranatriumzout Type III), de geschikte concentraties van de gewenste remmer en 120 μg microsomaal eiwit. Het (4- 14C)A wordt toegevoegd als een oplossing in 1,7% ethanol in 0,05 M kaliumfosfaatbuffer (pH 7,4), zodat de uiteindelijke concentratie ethanol niet meer dan 0,02% (v/v) bedraagt. De reactie wordt gestart door de toevoeging van enzym en na 20 min gestopt door de toevoeging van 7 vol ethylacetaat. Het mengsel wordt geschud op een vortexmixer en gedurende 5 min gecentrifugeerd bij 600 g. De waterige fase wordt opnieuw geëxtraheerd met 7 vol ethylacetaat, en de gecombineerde extracten worden tot droogte verdampt met behulp van een Evapo-Mix. Meer dan 99% van de radioactiviteit van toegevoegd [4- 14C] wordt teruggevonden met dit extractiesysteem. Het verkregen residu wordt opgelost in 150 μL aceton, en 100 μL aliquots worden gedurende 65 min gechromatografeerd op dunne-laagplaten voorbekleed met silicagel 60 met behulp van ethylacetaat: isooctaan (140:60, v/v; systeem A) of tolueen: chloroform: methanol (70:140:20; systeem B). De radioactieve zones van de plaat worden gelokaliseerd met een Berthold LB 2760 dunne-laagscanner. De radioactieve estradiol (E2) en estron (E1) pieken worden geïdentificeerd door vergelijking met authentieke standaarden. De corresponderende bindingsband van silicagel wordt overgebracht naar flacons die 10 mL scintillatievloeistof bevatten en geteld met een 6880 Liquid Scintillatiesysteem.
In vivo

Letrozole inhibits aromatase in vivo with ED50 of 1-3 μg/kg p.o.. This compound displays anti-endocrine effects. It inhibits androstenedione-induced uterine hypertrophy in immature rats with ED50 of 1-3 μg/kg. In the adult female rat, this compound (0.3-1 mg/kg daily p.o., 14 days) completely interrupts ovarian cyclicity and reduces uterine weight and serum estradiol (E2) concentrations to a similar extent to that seen after ovariectomy. This chemical induces dose-dependent regression of estrogen-dependent, 9,10-dimethylbenz-a-anthracene-induced mammary tumors in adult female rats. The ED50 for it is determined to be 10 - 30 µg/kg/day, with complete inhibition at a daily dose of 10 µg/day. It produces dose-dependent inhibition of tumor growth of MCF-7 cells transfected with human aromatase gene (MCF-7Ca) implanted athymic nude mice, with complete inhibition at 20 mg/kg per day p.o..

Referenties
  • [4] https://pubmed.ncbi.nlm.nih.gov/20095792/
  • [5] https://pubmed.ncbi.nlm.nih.gov/7628871/
  • [6] https://pubmed.ncbi.nlm.nih.gov/2973160/

Informatie over klinische proeven (Clinical Trial Information)

(gegevens van https://clinicaltrials.gov, bijgewerkt op 2024-05-22)

NCT-nummer Werving Aandoeningen Sponsor/medewerkers Startdatum Fasen
NCT06143631 Not yet recruiting
Leiomyoma Uterine|Leiomyoma|Fibroid|Fibroid Uterus
University of California San Francisco|Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
May 13 2024 Phase 4
NCT05872204 Recruiting
Low Grade Serous Ovarian Carcinoma|Adult Type Granulosa Cell Tumor
Universitaire Ziekenhuizen KU Leuven|Kom Op Tegen Kanker|Eli Lilly and Company|European Network of Gynaecological Oncological Trial Groups (ENGOT)
November 30 2023 Phase 2