All-trans retinoic acid modulates AHR signaling and its downstream target gene, CYP1A in human hepatoma cells

Document Type : Original Article


Department of Pharmacology and Toxicology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran.


The aryl hydrocarbon receptor (AHR) was identified for its mediating toxicological role in response to variety of the polycyclic aromatic hydrocarbon family of environmental contaminants however, recent data indicate that the AHR can be activated with different types of endogenous and exogenous chemicals. The aim of this study was to gain more information about the mechanisms that regulate expression of the AHR target gene, CYP1A1 by All-trans retinoic acid (ATRA) in human hepatoma cells (HepG2 and Huh7). The human hepatoma cell line (HepG2-XRE-Luc) carrying cytochrome P4501A1 (CYP1A1) response elements, HepG2 and Huh7 cells were exposed to different doses of ATRA (1-50 µM) and CYP1A1 transcription and enzymatic activities, as well as gene expression were measured. Our results showed that ATRA is able to induce CYP1A1 in an AHR-dependent manner using CH223191 as an AHR antagonist. The result showed that different doses of ATRA have no significant effects on cell viability.CYP1A1 enzyme and transcription activities as well as CYP1A1 mRNA for all treated group showed a significant elevation by ATRA. To better understand the mechanism underlying AHR activation by ATRA more molecular studies are needed. 
Please cite this article as: Fereshteh Asadi Dolatabad, Sepideh Maghami, Najmeh Ekhtiyardar, Shadi Maghsodlo, Afshin Mohammadi-Bardbori. All-trans retinoic acid  modulates AHR signaling and its downstream target gene, CYP1A in human hepatoma cells. Trends in Pharmaceutical Sciences. 2022;8(3):127-134. doi: 110.30476/TIPS.2022.94166.1135.


1.    Nebert DW, Dalton TP. The role of cytochrome P450 enzymes in endogenous signalling pathways and environmental carcinogenesis. Nat Rev Cancer. 2006 Dec;6(12):947-60. doi: 10.1038/nrc2015. PMID: 17128211.
2.    Arabnezhad MR, Montazeri-Najafabady N, Chatrabnous N, Ghafarian Bahreman A, Mohammadi-Bardbori A. Anti-androgenic effect of 6-formylindolo[3,2-b]carbazole (FICZ) in LNCaP cells is mediated by the aryl hydrocarbon-androgen receptors cross-talk. Steroids. 2020 Jan;153:108508. doi: 10.1016/j.steroids.2019.108508. Epub 2019 Oct 3. PMID: 31586605.
3.    Omidi M, Ghafarian-Bahraman A, Mohammadi-Bardbori A. GSH/GSSG redox couple plays central role in aryl hydrocarbon receptor-dependent modulation of cytochrome P450 1A1. J Biochem Mol Toxicol. 2018 Jul 5:e22164. doi: 10.1002/jbt.22164. Epub ahead of print. PMID: 29975444.
4.    Mohammadi-Bardbori A, Omidi M, Arabnezhad MR. Impact of CH223191-Induced Mitochondrial Dysfunction on Its Aryl Hydrocarbon Receptor Agonistic and Antagonistic Activities. Chem Res Toxicol. 2019 Apr 15;32(4):691-697. doi: 10.1021/acs.chemrestox.8b00371. Epub 2019 Mar 4. PMID: 30793600.
5.    Mohammadi-Bardbori A, Bengtsson J, Rannug U, Rannug A, Wincent E. Quercetin, resveratrol, and curcumin are indirect activators of the aryl hydrocarbon receptor (AHR). Chem Res Toxicol. 2012 Sep 17;25(9):1878-84. doi: 10.1021/tx300169e. Epub 2012 Aug 28. PMID: 22867086.
6.    Mohammadi H, Daryabor G, Ghaffarian Bahraman A, Keshavarzi M, Kalantar K, Mohammadi-Bardbori A. Aryl hydrocarbon receptor engagement during redox alteration determines the fate of CD4+ T cells in C57BL/6 mice. J Biochem Mol Toxicol. 2021 Aug;35(8):e22821. doi: 10.1002/jbt.22821. Epub 2021 May 26. PMID: 34036678.
7.    Mohammadi-Bardbori A, Akbarizadeh AR, Delju F, Rannug A. Chromatin remodeling by curcumin alters endogenous aryl hydrocarbon receptor signaling. Chem Biol Interact. 2016 May 25;252:19-27. doi: 10.1016/j.cbi.2016.03.037. Epub 2016 Apr 1. PMID: 27041069.
8.    Mohammadi-Bardbori A, Bastan F, Akbarizadeh AR. The highly bioactive molecule and signal substance 6-formylindolo[3,2-b]carbazole (FICZ) plays bi-functional roles in cell growth and apoptosis in vitro. Arch Toxicol. 2017 Oct;91(10):3365-3372. doi: 10.1007/s00204-017-1950-9. Epub 2017 Mar 13. PMID: 28289825.
9.    Mohammadi-Bardbori A, Vikström Bergander L, Rannug U, Rannug A. NADPH Oxidase-Dependent Mechanism Explains How Arsenic and Other Oxidants Can Activate Aryl Hydrocarbon Receptor Signaling. Chem Res Toxicol. 2015 Dec 21;28(12):2278-86. doi: 10.1021/acs.chemrestox.5b00415. Epub 2015 Nov 16. PMID: 26535918.
10.    Omidi M, Niknahad H, Noorafshan A, Fardid R, Nadimi E, Naderi S, Bakhtari A, Mohammadi-Bardbori A. Co-exposure to an Aryl Hydrocarbon Receptor Endogenous Ligand, 6-Formylindolo[3,2-b]carbazole (FICZ), and Cadmium Induces Cardiovascular Developmental Abnormalities in Mice. Biol Trace Elem Res. 2019 Feb;187(2):442-451. doi: 10.1007/s12011-018-1391-1. Epub 2018 May 28. PMID: 29808276.
11.    Wincent E, Bengtsson J, Mohammadi Bardbori A, Alsberg T, Luecke S, Rannug U, Rannug A. Inhibition of cytochrome P4501-dependent clearance of the endogenous agonist FICZ as a mechanism for activation of the aryl hydrocarbon receptor. Proc Natl Acad Sci U S A. 2012 Mar 20;109(12):4479-84. doi: 10.1073/pnas.1118467109. Epub 2012 Mar 5. PMID: 22392998; PMCID: PMC3311358.
12.    Whitlock JP Jr. Induction of cytochrome P4501A1. Annu Rev Pharmacol Toxicol. 1999;39:103-25. doi: 10.1146/annurev.pharmtox.39.1.103. PMID: 10331078.
13.    Ma Q, Baldwin KT. 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced degradation of aryl hydrocarbon receptor (AhR) by the ubiquitin-proteasome pathway. Role of the transcription activaton and DNA binding of AhR. J Biol Chem. 2000 Mar 24;275(12):8432-8. doi: 10.1074/jbc.275.12.8432. PMID: 10722677.
14.    Morita T, Miyakawa K, Jeremiah SS, Yamaoka Y, Sada M, Kuniyoshi T, Yang J, Kimura H, Ryo A. All-Trans Retinoic Acid Exhibits Antiviral Effect against SARS-CoV-2 by Inhibiting 3CLpro Activity. Viruses. 2021 Aug 23;13(8):1669. doi: 10.3390/v13081669. PMID: 34452533; PMCID: PMC8402917.
15.    Esteban J, Sánchez-Pérez I, Hamscher G, Miettinen HM, Korkalainen M, Viluksela M, Pohjanvirta R, Håkansson H. Role of aryl hydrocarbon receptor (AHR) in overall retinoid metabolism: Response comparisons to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure between wild-type and AHR knockout mice. Reprod Toxicol. 2021 Apr;101:33-49. doi: 10.1016/j.reprotox.2021.02.004. Epub 2021 Feb 16. PMID: 33607186.
16.    Liang X, Zhou R, Li Y, Yang L, Su M, Lai KP. Clinical characterization and therapeutic targets of vitamin A in patients with hepatocholangiocarcinoma and coronavirus disease. Aging (Albany NY). 2021 Jun 27;13(12):15785-15800. doi: 10.18632/aging.203220. Epub 2021 Jun 27. PMID: 34176789; PMCID: PMC8266307.
17.    Berghard A, Gradin K, Pongratz I, Whitelaw M, Poellinger L. Cross-coupling of signal transduction pathways: the dioxin receptor mediates induction of cytochrome P-450IA1 expression via a protein kinase C-dependent mechanism. Mol Cell Biol. 1993 Jan;13(1):677-89. doi: 10.1128/mcb.13.1.677-689.1993. PMID: 8380231; PMCID: PMC358946.
18.    Fallone F, Villard PH, Sérée E, Rimet O, Nguyen QB, Bourgarel-Rey V, Fouchier F, Barra Y, Durand A, Lacarelle B. Retinoids repress Ah receptor CYP1A1 induction pathway through the SMRT corepressor. Biochem Biophys Res Commun. 2004 Sep 17;322(2):551-6. doi: 10.1016/j.bbrc.2004.07.153. PMID: 15325265.
19.    Ohno M, Ikenaka Y, Ishizuka M. All-trans retinoic acid inhibits the recruitment of ARNT to DNA, resulting in the decrease of CYP1A1 mRNA expression in HepG2 cells. Biochem Biophys Res Commun. 2012 Jan 6;417(1):484-9. doi: 10.1016/j.bbrc.2011.11.146. Epub 2011 Dec 8. PMID: 22177959.
20.    Vecchini F, Lenoir-Viale MC, Cathelineau C, Magdalou J, Bernard BA, Shroot B. Presence of a retinoid responsive element in the promoter region of the human cytochrome P4501A1 gene. Biochem Biophys Res Commun. 1994 Jun 30;201(3):1205-12. doi: 10.1006/bbrc.1994.1833. PMID: 8024563.
21.    Vecchini F, Mace K, Magdalou J, Mahe Y, Bernard BA, Shroot B. Constitutive and inducible expression of drug metabolizing enzymes in cultured human keratinocytes. Br J Dermatol. 1995 Jan;132(1):14-21. doi: 10.1111/j.1365-2133.1995.tb08618.x. PMID: 7756127.
22.    Schulthess P, Löffler A, Vetter S, Kreft L, Schwarz M, Braeuning A, Blüthgen N. Signal integration by the CYP1A1 promoter--a quantitative study. Nucleic Acids Res. 2015 Jun 23;43(11):5318-30. doi: 10.1093/nar/gkv423. Epub 2015 May 1. PMID: 25934798; PMCID: PMC4477655.
23.    Gambone CJ, Hutcheson JM, Gabriel JL, Beard RL, Chandraratna RA, Soprano KJ, Soprano DR. Unique property of some synthetic retinoids: activation of the aryl hydrocarbon receptor pathway. Mol Pharmacol. 2002 Feb;61(2):334-42. doi: 10.1124/mol.61.2.334. PMID: 11809858.