Details of the Drug Combination

General Information of Drug Combination (ID: DC5AWF5)

• Drug Combination Name: Letrozole + Mepacrine
• Indication: Carcinoma; Status: Investigative [1]
• Component Drugs:
  Letrozole (DMH07Y3): Small molecular drug
  Mepacrine (DMU8L7C): Small molecular drug
• High-throughput Screening Result:
  Testing Cell Line: MCF7
  Zero Interaction Potency (ZIP) Score: 3.46
  Bliss Independence Score: 7.28
  Loewe Additivity Score: 2.23
  LHighest Single Agent (HSA) Score: 2.03

Molecular Interaction Atlas of This Drug Combination

Indication(s) of Letrozole

Disease Entry	ICD 11	Status	REF
Estrogen-receptor positive breast cancer	N.A.	Approved	[2]
Hormonally-responsive breast cancer	2C60-2C65	Approved	[3]

Letrozole Interacts with 1 DTT Molecule(s)

DTT Name	DTT ID	UniProt ID	Mode of Action	REF
Aromatase (CYP19A1)	TTSZLWK	CP19A_HUMAN	Inhibitor	[5]

Letrozole Interacts with 3 DME Molecule(s)

DME Name	DME ID	UniProt ID	Mode of Action	REF
Cytochrome P450 3A4 (CYP3A4)	DE4LYSA	CP3A4_HUMAN	Metabolism	[6]
Aromatase (CYP19A1)	DEQX145	CP19A_HUMAN	Metabolism	[7]
Cytochrome P450 2A6 (CYP2A6)	DEJVYAZ	CP2A6_HUMAN	Metabolism	[8]

Letrozole Interacts with 7 DOT Molecule(s)

DOT Name	DOT ID	UniProt ID	Mode of Action	REF
Adenylate kinase isoenzyme 1 (AK1)	OT614AR3	KAD1_HUMAN	Increases ADR	[9]
Follitropin subunit beta (FSHB)	OTGLS283	FSHB_HUMAN	Increases Expression	[10]
Lutropin subunit beta (LHB)	OT5GBOVJ	LSHB_HUMAN	Increases Expression	[10]
G1/S-specific cyclin-D2 (CCND2)	OTDULQF9	CCND2_HUMAN	Decreases Expression	[11]
Cyclin-dependent kinase inhibitor 1 (CDKN1A)	OTQWHCZE	CDN1A_HUMAN	Increases Expression	[12]
Small ribosomal subunit protein eS6 (RPS6)	OTT4D1LN	RS6_HUMAN	Decreases Phosphorylation	[11]
Fibroblast growth factor 22 (FGF22)	OTVIX6J0	FGF22_HUMAN	Increases Expression	[13]

Indication(s) of Mepacrine

Disease Entry	ICD 11	Status	REF
Discovery agent	N.A.	Investigative	[4]

Mepacrine Interacts with 1 DTT Molecule(s)

DTT Name	DTT ID	UniProt ID	Mode of Action	REF
Phospholipase A2 (PLA2G1B)	TT9V5JH	PA21B_HUMAN	Inhibitor	[4]

Mepacrine Interacts with 1 DTP Molecule(s)

DTP Name	DTP ID	UniProt ID	Mode of Action	REF
Breast cancer resistance protein (ABCG2)	DTI7UX6	ABCG2_HUMAN	Substrate	[14]

Mepacrine Interacts with 2 DME Molecule(s)

DME Name	DME ID	UniProt ID	Mode of Action	REF
Cytochrome P450 3A4 (CYP3A4)	DE4LYSA	CP3A4_HUMAN	Metabolism	[15]
Cytochrome P450 3A5 (CYP3A5)	DEIBDNY	CP3A5_HUMAN	Metabolism	[15]

Mepacrine Interacts with 11 DOT Molecule(s)

DOT Name	DOT ID	UniProt ID	Mode of Action	REF
Myc proto-oncogene protein (MYC)	OTPV5LUK	MYC_HUMAN	Decreases Expression	[16]
Poly polymerase 1 (PARP1)	OT310QSG	PARP1_HUMAN	Increases Cleavage	[17]
1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase gamma-1 (PLCG1)	OTSBQR6D	PLCG1_HUMAN	Decreases Phosphorylation	[18]
Mitogen-activated protein kinase 3 (MAPK3)	OTCYKGKO	MK03_HUMAN	Decreases Phosphorylation	[17]
Mitogen-activated protein kinase 1 (MAPK1)	OTH85PI5	MK01_HUMAN	Decreases Phosphorylation	[17]
Catenin beta-1 (CTNNB1)	OTZ932A3	CTNB1_HUMAN	Decreases Expression	[16]
Cyclin-dependent kinase inhibitor 1 (CDKN1A)	OTQWHCZE	CDN1A_HUMAN	Decreases Expression	[19]
Casein kinase I isoform alpha (CSNK1A1)	OTJ6O1IC	KC1A_HUMAN	Increases Expression	[16]
Forkhead box protein P3 (FOXP3)	OTA9Z9OC	FOXP3_HUMAN	Increases Expression	[17]
F-box/WD repeat-containing protein 1A (BTRC)	OT2EZDGR	FBW1A_HUMAN	Decreases Expression	[17]
ATP-dependent translocase ABCB1 (ABCB1)	OTEJROBO	MDR1_HUMAN	Increases Transport	[15]

References

• [1] CheMBL Affinity Phenotypic Cellular Interaction Assay ID: CHEMBL1126165
• [2] Letrozole FDA Label
• [3] URL: http://www.guidetopharmacology.org Nucleic Acids Res. 2015 Oct 12. pii: gkv1037. The IUPHAR/BPS Guide to PHARMACOLOGY in 2016: towards curated quantitative interactions between 1300 protein targets and 6000 ligands. (Ligand id: 5209).
• [4] Involvement of protein kinase C activation in L-leucine-induced stimulation of protein synthesis in l6 myotubes. Cytotechnology. 2003 Nov;43(1-3):97-103.
• [5] Aromatase inhibitors--theoretical concept and present experiences in the treatment of endometriosis. Zentralbl Gynakol. 2003 Jul-Aug;125(7-8):247-51.
• [6] Inhibition of drug metabolizing cytochrome P450s by the aromatase inhibitor drug letrozole and its major oxidative metabolite 4,4'-methanol-bisbenzonitrile in vitro. Cancer Chemother Pharmacol. 2009 Oct;64(5):867-75.
• [7] Double-blind, randomised, multicentre endocrine trial comparing two letrozole doses, in postmenopausal breast cancer patients. Eur J Cancer. 1999 Feb;35(2):208-13.
• [8] Letrozole concentration is associated with CYP2A6 variation but not with arthralgia in patients with breast cancer. Breast Cancer Res Treat. 2018 Nov;172(2):371-379.
• [9] ADReCS-Target: target profiles for aiding drug safety research and application. Nucleic Acids Res. 2018 Jan 4;46(D1):D911-D917. doi: 10.1093/nar/gkx899.
• [10] Aromatase inhibition, testosterone, and seizures. Epilepsy Behav. 2004 Apr;5(2):260-3. doi: 10.1016/j.yebeh.2003.12.001.
• [11] Dual inhibition of mTOR and estrogen receptor signaling in vitro induces cell death in models of breast cancer. Clin Cancer Res. 2005 Jul 15;11(14):5319-28. doi: 10.1158/1078-0432.CCR-04-2402.
• [12] Synergistic activity of letrozole and sorafenib on breast cancer cells. Breast Cancer Res Treat. 2010 Nov;124(1):79-88. doi: 10.1007/s10549-009-0714-5. Epub 2010 Jan 7.
• [13] Clomiphene citrate versus letrozole: molecular analysis of the endometrium in women with polycystic ovary syndrome. Fertil Steril. 2011 Oct;96(4):1051-6. doi: 10.1016/j.fertnstert.2011.07.1092.
• [14] Arginine-482 is not essential for transport of antibiotics, primary bile acids and unconjugated sterols by the human breast cancer resistance protein (ABCG2). Biochem J. 2005 Jan 15;385(Pt 2):419-26.
• [15] Quinacrine is mainly metabolized to mono-desethyl quinacrine by CYP3A4/5 and its brain accumulation is limited by P-glycoprotein. Drug Metab Dispos. 2006 Jul;34(7):1136-44.
• [16] Nanoquinacrine caused apoptosis in oral cancer stem cells by disrupting the interaction between GLI1 and catenin through activation of GSK3. Toxicol Appl Pharmacol. 2017 Sep 1;330:53-64. doi: 10.1016/j.taap.2017.07.008. Epub 2017 Jul 15.
• [17] Quinacrine induces the apoptosis of human leukemia U937 cells through FOXP3/miR-183/-TrCP/SP1 axis-mediated BAX upregulation. Toxicol Appl Pharmacol. 2017 Nov 1;334:35-46. doi: 10.1016/j.taap.2017.08.019. Epub 2017 Sep 1.
• [18] Quinacrine is active in preclinical models of glioblastoma through suppressing angiogenesis, inducing oxidative stress and activating AMPK. Toxicol In Vitro. 2022 Sep;83:105420. doi: 10.1016/j.tiv.2022.105420. Epub 2022 Jun 17.
• [19] Multiple-endpoint in vitro carcinogenicity test in human cell line TK6 distinguishes carcinogens from non-carcinogens and highlights mechanisms of action. Arch Toxicol. 2021 Jan;95(1):321-336. doi: 10.1007/s00204-020-02902-3. Epub 2020 Sep 10.