Aryl Hydrocarbon Receptor (AhR) Signaling in Colonic Cells and Tumors.

Autor:	Safe S; Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA., Han H; Program in Integrative Nutrition and Complex Diseases, Department of Nutrition, Texas A&M University, College Station, TX 77843, USA., Jayaraman A; Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA., Davidson LA; Program in Integrative Nutrition and Complex Diseases, Department of Nutrition, Texas A&M University, College Station, TX 77843, USA., Allred CD; Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC 27412, USA., Ivanov I; Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843, USA., Yang Y; Program in Integrative Nutrition and Complex Diseases, Department of Nutrition, Texas A&M University, College Station, TX 77843, USA.; Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843, USA., Cai JJ; Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843, USA., Chapkin RS; Program in Integrative Nutrition and Complex Diseases, Department of Nutrition, Texas A&M University, College Station, TX 77843, USA.
Jazyk:	angličtina
Zdroj:	Receptors (Basel, Switzerland) [Receptors (Basel)] 2023 Mar; Vol. 2 (1), pp. 93-99. Date of Electronic Publication: 2023 Feb 08.
DOI:	10.3390/receptors2010005
Abstrakt:	The aryl hydrocarbon receptor (AhR) is overexpressed in many tumor types and exhibits tumor-specific tumor promoter and tumor suppressor-like activity. In colon cancer, most but not all studies suggest that the AhR exhibits tumor suppressor activity which is enhanced by AhR ligands acting as agonists. Our studies investigated the role of the AhR in colon tumorigenesis using wild-type and AhR-knockout mice, the inflammation model of colon tumorigenesis using mice treated with azoxymethane (AOM)/dextran sodium sulfate (DSS) and APC S580/+ ; Kras G12D/+ mice all of which form intestinal tumors. The effects of tissue-specific AhR loss in the intestine of the tumor-forming mice on colonic stem cells, organoid-initiating capacity, colon tumor formation and mechanisms of AhR-mediated effects were investigated. Loss of AhR enhanced stem cell and tumor growth and in the AOM/DSS model AhR-dependent suppression of FOXM1 and downstream genes was important for AhR-dependent anticancer activity. Furthermore, the effectiveness of interleukin-22 (IL22) in colonic epithelial cells was also dependent on AhR expression. IL22 induced phosphorylation of STAT3, inhibited colonic organoid growth, promoted colonic cell proliferation in vivo and enhanced DNA repair in AOM/DSS-induced tumors. In this mouse model, the AhR suppressed SOCS3 expression and enhanced IL22-mediated activation of STAT3, whereas the loss of the AhR increased levels of SOCS3 which in turn inhibited IL22-induced STAT3 activation. In the APC S580/+ ; Kras G12D/+ mouse model, the loss of the AhR enhanced Wnt signaling and colon carcinogenesis. Results in both mouse models of colon carcinogenesis were complemented by single cell transcriptomics on colonic intestinal crypts which also showed that AhR deletion promoted expression of FOXM1-regulated genes in multiple colonic cell subtypes. These results support the role of the AhR as a tumor suppressor-like gene in the colon. Competing Interests: Conflicts of Interest: The authors declare no conflict of interest.
Databáze:	MEDLINE
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