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Congues F, Wang P, Lee J, Lin D, Shahid A, Xie J, Huang Y. Targeting aryl hydrocarbon receptor to prevent cancer in barrier organs. Biochem Pharmacol 2024; 223:116156. [PMID: 38518996 PMCID: PMC11144369 DOI: 10.1016/j.bcp.2024.116156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 03/08/2024] [Accepted: 03/19/2024] [Indexed: 03/24/2024]
Abstract
The skin, lung, and gut are important barrier organs that control how the body reacts to environmental stressors such as ultraviolet (UV) radiation, air pollutants, dietary components, and microorganisms. The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that plays an important role in maintaining homeostasis of barrier organs. AhR was initially discovered as a receptor for environmental chemical carcinogens such as polycyclic aromatic hydrocarbons (PAHs). Activation of AhR pathways by PAHs leads to increased DNA damage and mutations which ultimately lead to carcinogenesis. Ongoing evidence reveals an ever-expanding role of AhR. Recently, AhR has been linked to immune systems by the interaction with the development of natural killer (NK) cells, regulatory T (Treg) cells, and T helper 17 (Th17) cells, as well as the production of immunosuppressive cytokines. However, the role of AhR in carcinogenesis is not as straightforward as we initially thought. Although AhR activation has been shown to promote carcinogenesis in some studies, others suggest that it may act as a tumor suppressor. In this review, we aim to explore the role of AhR in the development of cancer that originates from barrier organs. We also examined the preclinical efficacy data of AhR agonists and antagonists on carcinogenesis to determine whether AhR modulation can be a viable option for cancer chemoprevention.
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Affiliation(s)
- Francoise Congues
- Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Pengcheng Wang
- Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA; Department of Stomatology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
| | - Joshua Lee
- Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Daphne Lin
- Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Ayaz Shahid
- Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Jianming Xie
- Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Ying Huang
- Department of Biotechnology and Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA.
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2
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Vázquez-Gómez G, Petráš J, Dvořák Z, Vondráček J. Aryl hydrocarbon receptor (AhR) and pregnane X receptor (PXR) play both distinct and common roles in the regulation of colon homeostasis and intestinal carcinogenesis. Biochem Pharmacol 2023; 216:115797. [PMID: 37696457 DOI: 10.1016/j.bcp.2023.115797] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/13/2023]
Abstract
Both aryl hydrocarbon receptor (AhR) and pregnane X receptor (PXR) belong among key regulators of xenobiotic metabolism in the intestinal tissue. AhR in particular is activated by a wide range of environmental and dietary carcinogens. The data accumulated over the last two decades suggest that both of these transcriptional regulators play a much wider role in the maintenance of gut homeostasis, and that both transcription factors may affect processes linked with intestinal tumorigenesis. Intestinal epithelium is continuously exposed to a wide range of AhR, PXR and dual AhR/PXR ligands formed by intestinal microbiota or originating from diet. Current evidence suggests that specific ligands of both AhR and PXR can protect intestinal epithelium against inflammation and assist in the maintenance of epithelial barrier integrity. AhR, and to a lesser extent also PXR, have been shown to play a protective role against inflammation-induced colon cancer, or, in mouse models employing overactivation of Wnt/β-catenin signaling. In contrast, other evidence suggests that both receptors may contribute to modulation of transformed colon cell behavior, with a potential to promote cancer progression and/or chemoresistance. The review focuses on both overlapping and separate roles of the two receptors in these processes, and on possible implications of their activity within the context of intestinal tissue.
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Affiliation(s)
- Gerardo Vázquez-Gómez
- Department of Cytokinetics, Institute of Biophysics of the CAS, Královopolská 135, 61265 Brno, Czech Republic
| | - Jiří Petráš
- Department of Cytokinetics, Institute of Biophysics of the CAS, Královopolská 135, 61265 Brno, Czech Republic; Department of Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
| | - Zdeněk Dvořák
- Department of Cell Biology and Genetics, Faculty of Science, Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
| | - Jan Vondráček
- Department of Cytokinetics, Institute of Biophysics of the CAS, Královopolská 135, 61265 Brno, Czech Republic.
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Elson DJ, Nguyen BD, Korjeff NA, Wilferd SF, Puig-Sanvicens V, Sang Jang H, Bernales S, Chakravarty S, Belmar S, Ureta G, Finlay D, Plaisier CL, Kolluri SK. Suppression of Ah Receptor (AhR) increases the aggressiveness of TNBC cells and 11-Cl-BBQ-activated AhR inhibits their growth. Biochem Pharmacol 2023; 215:115706. [PMID: 37506922 DOI: 10.1016/j.bcp.2023.115706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 07/30/2023]
Abstract
Triple-negative breast cancer (TNBC) represents around 15% of the 2.26 million breast cancers diagnosed worldwide annually and has the worst outcome. Despite recent therapeutic advances, there remains a lack of targeted therapies for this breast cancer subtype. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor with biological roles in regulating development, xenobiotic metabolism, cell cycle progression and cell death. AhR activation by select ligands can promote tumor suppression in multiple cancer types. AhR can negatively regulate the activity of different oncogenic signaling pathways and can directly upregulate tumor suppressor genes such as p27Kip1. To determine the role of AhR in TNBC, we generated AhR-deficient cancer cells and investigated the impact of AhR loss on TNBC cell growth phenotypes. We found that AhR-deficient MDA-MB-468 TNBC cells have increased proliferation and formed significantly more colonies compared to AhR expressing cells. These cells without AhR expression grew aggressively in vivo. To determine the molecular targets driving this phenotype, we performed transcriptomic profiling in AhR expressing and AhR knockout MDA-MB-468 cells and identified tyrosine receptor kinases, as well as other genes involved in proliferation, survival and clonogenicity that are repressed by AhR. In order to determine therapeutic targeting of AhR in TNBC, we investigated the anti-cancer effects of the novel AhR ligand 11-chloro-7H-benzimidazo[2,1-a]benzo[de]iso-quinolin-7-one (11-Cl-BBQ), which belongs to a class of high affinity, rapidly metabolized AhR ligands called benzimidazoisoquinolines (BBQs). 11-Cl-BBQ induced AhR-dependent cancer cell-selective growth inhibition and strongly inhibited colony formation in TNBC cells.
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Affiliation(s)
- Daniel J Elson
- Cancer Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, United States
| | - Bach D Nguyen
- Cancer Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, United States
| | - Nicholas A Korjeff
- Cancer Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, United States
| | - Sierra F Wilferd
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, United States
| | - Veronica Puig-Sanvicens
- Cancer Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, United States
| | - Hyo Sang Jang
- Cancer Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, United States
| | - Sebastian Bernales
- Praxis Biotech, San Francisco, CA 94158, United States; Fundación Ciencia & Vida, Centro Científico y Tecnológico Ciencia & Vida, Avda. Del valle Norte 725, Santiago, Chile
| | | | - Sebastián Belmar
- Praxis Biotech, San Francisco, CA 94158, United States; Merken Biotech, Avda. Del valle Norte 725, Santiago, Chile
| | - Gonzalo Ureta
- Praxis Biotech, San Francisco, CA 94158, United States; Merken Biotech, Avda. Del valle Norte 725, Santiago, Chile
| | - Darren Finlay
- Sanford Burnham Prebys Medical Discovery Institute, NCI Designated Cancer Center, La Jolla, CA 92037, United States
| | - Christopher L Plaisier
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, United States
| | - Siva K Kolluri
- Cancer Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, United States; Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, United States.
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Chen Y, Wang Y, Fu Y, Yin Y, Xu K. Modulating AHR function offers exciting therapeutic potential in gut immunity and inflammation. Cell Biosci 2023; 13:85. [PMID: 37179416 PMCID: PMC10182712 DOI: 10.1186/s13578-023-01046-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023] Open
Abstract
Aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a classical exogenous synthetic ligand of AHR that has significant immunotoxic effects. Activation of AHR has beneficial effects on intestinal immune responses, but inactivation or overactivation of AHR can lead to intestinal immune dysregulation and even intestinal diseases. Sustained potent activation of AHR by TCDD results in impairment of the intestinal epithelial barrier. However, currently, AHR research has been more focused on elucidating physiologic AHR function than on dioxin toxicity. The appropriate level of AHR activation plays a role in maintaining gut health and protecting against intestinal inflammation. Therefore, AHR offers a crucial target to modulate intestinal immunity and inflammation. Herein, we summarize our current understanding of the relationship between AHR and intestinal immunity, the ways in which AHR affects intestinal immunity and inflammation, the effects of AHR activity on intestinal immunity and inflammation, and the effect of dietary habits on intestinal health through AHR. Finally, we discuss the therapeutic role of AHR in maintaining gut homeostasis and relieving inflammation.
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Affiliation(s)
- Yue Chen
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450000, China
| | - Yadong Wang
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
| | - Yawei Fu
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450000, China
| | - Yulong Yin
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China
- College of Animal Science and Technology, Henan Agricultural University, Zhengzhou, 450000, China
| | - Kang Xu
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410125, China.
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Fu Y, Bi Z, Ji H, Elangbam M, Zhang Q, Qiu Y, Zhang W, Thakur C, Chen F. Disruption of the tumor suppressor-like activity of aryl hydrocarbon receptor by arsenic in epithelial cells and human lung cancer. Int J Biol Sci 2023; 19:1983-2001. [PMID: 37151890 PMCID: PMC10158013 DOI: 10.7150/ijbs.81423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 01/25/2023] [Indexed: 05/09/2023] Open
Abstract
As the most classic and extensively studied transcription factor in response to environmental toxic chemicals, the human aryl hydrocarbon receptor (AHR) has been implicated in mediating some oncogenic responses also. Limited information is available, however, on whether arsenic, a widely presented environmental carcinogen, can regulate AHR to exert its carcinogenic activity. Through chromatin immunoprecipitation and sequencing (ChIP-seq), CRISPR-Cas9 gene editing, RNA-seq, and immunohistochemistry (IHC), in this report we provided evidence showing that arsenic enforces TGFβ and other oncogenic signaling pathways in bronchial epithelial cells through disrupting the tumor suppressor-like activity of AHR. AHR is normally enriched on a number of oncogenic genes in addition to the known phase I/II enzymes, such as genes in TGFβ and Nrf2 signaling pathways and several known oncogenes. Arsenic treatment substantially reduced the binding of AHR on these genes followed by an increased expression of these genes. CRISPR-Cas9-based knockout of AHR followed by RNA-seq further demonstrated increased expression of the TGFβ signaling and some oncogenic signaling pathway genes in the AHR knockout cells. IHC studies on human tissue samples revealed that normal human lung tissues expressed high level of AHR. In contrast, the AHR expression was diminished in the lung cancer tissues. Accordingly, the data from this study suggest that AHR has tumor suppressor-like activity for human lung cancer, and one of the carcinogenic mechanisms of arsenic is likely mediated by the inhibition of arsenic on the tumor suppressor-like activity of AHR.
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Affiliation(s)
- Yao Fu
- Stony Brook Cancer Center, Department of Pathology, Renaissance School of Medicine, Stony Brook University, Lauterbur Drive, Stony Brook, NY 11794, USA
| | - Zhuoyue Bi
- Stony Brook Cancer Center, Department of Pathology, Renaissance School of Medicine, Stony Brook University, Lauterbur Drive, Stony Brook, NY 11794, USA
| | - Haoyan Ji
- Stony Brook Cancer Center, Department of Pathology, Renaissance School of Medicine, Stony Brook University, Lauterbur Drive, Stony Brook, NY 11794, USA
| | - Millie Elangbam
- Stony Brook Cancer Center, Department of Pathology, Renaissance School of Medicine, Stony Brook University, Lauterbur Drive, Stony Brook, NY 11794, USA
| | - Qian Zhang
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI 48201, USA
| | - Yiran Qiu
- Stony Brook Cancer Center, Department of Pathology, Renaissance School of Medicine, Stony Brook University, Lauterbur Drive, Stony Brook, NY 11794, USA
| | - Wenxuan Zhang
- Stony Brook Cancer Center, Department of Pathology, Renaissance School of Medicine, Stony Brook University, Lauterbur Drive, Stony Brook, NY 11794, USA
| | - Chitra Thakur
- Stony Brook Cancer Center, Department of Pathology, Renaissance School of Medicine, Stony Brook University, Lauterbur Drive, Stony Brook, NY 11794, USA
| | - Fei Chen
- Stony Brook Cancer Center, Department of Pathology, Renaissance School of Medicine, Stony Brook University, Lauterbur Drive, Stony Brook, NY 11794, USA
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Elson DJ, Kolluri SK. Tumor-Suppressive Functions of the Aryl Hydrocarbon Receptor (AhR) and AhR as a Therapeutic Target in Cancer. BIOLOGY 2023; 12:biology12040526. [PMID: 37106727 PMCID: PMC10135996 DOI: 10.3390/biology12040526] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/25/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor involved in regulating a wide range of biological responses. A diverse array of xenobiotics and endogenous small molecules bind to the receptor and drive unique phenotypic responses. Due in part to its role in mediating toxic responses to environmental pollutants, AhR activation has not been traditionally viewed as a viable therapeutic approach. Nonetheless, the expression and activation of AhR can inhibit the proliferation, migration, and survival of cancer cells, and many clinically approved drugs transcriptionally activate AhR. Identification of novel select modulators of AhR-regulated transcription that promote tumor suppression is an active area of investigation. The development of AhR-targeted anticancer agents requires a thorough understanding of the molecular mechanisms driving tumor suppression. Here, we summarized the tumor-suppressive mechanisms regulated by AhR with an emphasis on the endogenous functions of the receptor in opposing carcinogenesis. In multiple different cancer models, the deletion of AhR promotes increased tumorigenesis, but a precise understanding of the molecular cues and the genetic targets of AhR involved in this process is lacking. The intent of this review was to synthesize the evidence supporting AhR-dependent tumor suppression and distill insights for development of AhR-targeted cancer therapeutics.
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Affiliation(s)
- Daniel J. Elson
- Cancer Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA
| | - Siva K. Kolluri
- Cancer Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA
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Madison CA, Hillbrick L, Kuempel J, Albrecht GL, Landrock KK, Safe S, Chapkin RS, Eitan S. Intestinal epithelium aryl hydrocarbon receptor is involved in stress sensitivity and maintaining depressive symptoms. Behav Brain Res 2023; 440:114256. [PMID: 36528169 PMCID: PMC9839636 DOI: 10.1016/j.bbr.2022.114256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/03/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a key regulator in the microbiome-gut-brain axis, and AhR-active microbial metabolites modulate multiple neuronal responses. We recently demonstrated that 3,3'-diindolylmethane (DIM) and 1,4-dihydroxy-2-naphthoic acid (DHNA), two selective AhR modulators (SAhRMs), act as antidepressants in female mice. Thus, to examine the role of intestinal AhR in depression, anxiety, and spatial learning, this study employed transgenic mice in which the AhR was knockout only in the intestinal epithelium (AhRΔIEC). Additionally, this study examined whether the antidepressant effects of dietary DIM and DHNA is mediated by intestinal AhR. AhRΔIEC and WT female mice were fed daily with vehicle, 20 mg/kg DIM or DHNA for three weeks prior to four weeks of unpredictable chronic mild stress (UCMS). Mice were examined for weight gain, anhedonia-like behavior (sucrose preference test), anxiety levels (open field, light/dark, elevated plus maze, novelty-induced hypophagia, and marble burying tests), and spatial learning (Morris water maze). UCMS reduced weight gain in AhRΔIECs, but not WTs. Moreover, UCMS initially reduced sucrose preference in both AhRΔIECs and WTs, but over 4 weeks of UCMS, AhRΔIECs develop resilience to UCMS-induced anhedonia. Additionally, AhRΔIECs exhibit slightly reduced anxiety in certain tests and faster spatial learning. DIM and DHNA acted as antidepressants in both AhRΔIECs and WTs. Thus, this study suggests that intestinal AhR plays differential roles, mitigating stress effects on weight gain, and increasing stress effects on mood. However, the site of antidepressant action of SAhRMs, such as DIM and DHNA, is not dependent on the expression of intestinal AhR.
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Affiliation(s)
- Caitlin A Madison
- Behavioral and Cellular Neuroscience, Department of Psychological and Brain Sciences, Texas A&M University, 4235 TAMU, College Station, TX 77843, USA
| | - Lauren Hillbrick
- Behavioral and Cellular Neuroscience, Department of Psychological and Brain Sciences, Texas A&M University, 4235 TAMU, College Station, TX 77843, USA
| | - Jacob Kuempel
- Behavioral and Cellular Neuroscience, Department of Psychological and Brain Sciences, Texas A&M University, 4235 TAMU, College Station, TX 77843, USA
| | - Georgia Lee Albrecht
- Behavioral and Cellular Neuroscience, Department of Psychological and Brain Sciences, Texas A&M University, 4235 TAMU, College Station, TX 77843, USA
| | - Kerstin K Landrock
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA
| | - Stephen Safe
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX 77843-4466, USA
| | - Robert S Chapkin
- Department of Nutrition, Texas A&M University, College Station, TX 77843, USA
| | - Shoshana Eitan
- Behavioral and Cellular Neuroscience, Department of Psychological and Brain Sciences, Texas A&M University, 4235 TAMU, College Station, TX 77843, USA.
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Inhibition of Aryl Hydrocarbon Receptor (AhR) Expression Disrupts Cell Proliferation and Alters Energy Metabolism and Fatty Acid Synthesis in Colon Cancer Cells. Cancers (Basel) 2022; 14:cancers14174245. [PMID: 36077780 PMCID: PMC9454859 DOI: 10.3390/cancers14174245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/12/2022] [Accepted: 08/25/2022] [Indexed: 11/17/2022] Open
Abstract
Simple Summary Cancer cells undergo metabolic modifications in order to meet their high energetic demand. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcriptional factor primarily known as a xenobiotic sensor. However, this receptor seems to have a wide range of physiological roles in many processes including cell proliferation, migration or control of immune responses. AhR is often overexpressed in tumor cells of various tissue origin, and several studies have indicated that AhR may also contribute to regulation of cellular metabolism, including synthesis of fatty acids (FA), one of the major steps in metabolic transition. Potential links between the AhR and the control of tumor cell proliferation and metabolism thus deserve more attention. Abstract The aryl hydrocarbon receptor (AhR) plays a wide range of physiological roles in cellular processes such as proliferation, migration or control of immune responses. Several studies have also indicated that AhR might contribute to the regulation of energy balance or cellular metabolism. We observed that the AhR is upregulated in tumor epithelial cells derived from colon cancer patients. Using wild-type and the corresponding AhR knockout (AhR KO) variants of human colon cancer cell lines HCT116 and HT-29, we analyzed possible role(s) of the AhR in cell proliferation and metabolism, with a focus on regulation of the synthesis of fatty acids (FAs). We observed a decreased proliferation rate in the AhR KO cells, which was accompanied with altered cell cycle progression, as well as a decreased ATP production. We also found reduced mRNA levels of key enzymes of the FA biosynthetic pathway in AhR KO colon cancer cells, in particular of stearoyl-CoA desaturase 1 (SCD1). The loss of AhR was also associated with reduced expression and/or activity of components of the PI3K/Akt pathway, which controls lipid metabolism, and other lipogenic transcriptional regulators, such as sterol regulatory element binding transcription factor 1 (SREBP1). Together, our data indicate that disruption of AhR activity in colon tumor cells may, likely in a cell-specific manner, limit their proliferation, which could be linked with a suppressive effect on their endogenous FA metabolism. More attention should be paid to potential mechanistic links between overexpressed AhR and colon tumor cell metabolism.
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OUP accepted manuscript. Carcinogenesis 2022; 43:203-216. [DOI: 10.1093/carcin/bgac007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 01/04/2022] [Accepted: 01/29/2022] [Indexed: 11/13/2022] Open
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Han H, Davidson LA, Fan YY, Landrock KK, Jayaraman A, Safe SH, Chapkin RS. Loss of aryl hydrocarbon receptor suppresses the response of colonic epithelial cells to IL22 signaling by upregulating SOCS3. Am J Physiol Gastrointest Liver Physiol 2022; 322:G93-G106. [PMID: 34755534 PMCID: PMC8714253 DOI: 10.1152/ajpgi.00074.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 11/04/2021] [Accepted: 11/08/2021] [Indexed: 01/31/2023]
Abstract
IL22 signaling plays an important role in maintaining gastrointestinal epithelial barrier function, cell proliferation, and protection of intestinal stem cells from genotoxicants. Emerging studies indicate that the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, promotes production of IL22 in gut immune cells. However, it remains to be determined if AhR signaling can also affect the responsiveness of colonic epithelial cells to IL22. Here, we show that IL22 treatment induces the phosphorylation of STAT3, inhibits colonic organoid growth, and promotes colonic cell proliferation in vivo. Notably, intestinal cell-specific AhR knockout (KO) reduces responsiveness to IL22 and compromises DNA damage response after exposure to carcinogen, in part due to the enhancement of suppressor of cytokine signaling 3 (SOCS3) expression. Deletion of SOCS3 increases levels of pSTAT3 in AhR KO organoids, and phenocopies the effects of IL22 treatment on wild-type (WT) organoid growth. In addition, pSTAT3 levels are inversely associated with increased azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colon tumorigenesis in AhR KO mice. These findings indicate that AhR function is required for optimal IL22 signaling in colonic epithelial cells and provide rationale for targeting AhR as a means of reducing colon cancer risk.NEW & NOTEWORTHY AhR is a key transcription factor controlling expression of IL22 in gut immune cells. In this study, we show for the first time that AhR signaling also regulates IL22 response in colonic epithelial cells by modulating SOCS3 expression.
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Affiliation(s)
- Huajun Han
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Laurie A Davidson
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas
- Department of Nutrition, Texas A&M University, College Station, Texas
| | - Yang-Yi Fan
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas
- Department of Nutrition, Texas A&M University, College Station, Texas
| | - Kerstin K Landrock
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas
- Department of Nutrition, Texas A&M University, College Station, Texas
| | - Arul Jayaraman
- Department of Chemical Engineering, Texas A&M University, College Station, Texas
| | - Stephen H Safe
- Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas
| | - Robert S Chapkin
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
- Department of Nutrition, Texas A&M University, College Station, Texas
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11
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Yang Y, Osorio D, Davidson LA, Han H, Mullens DA, Jayaraman A, Safe S, Ivanov I, Cai JJ, Chapkin RS. Single-cell RNA Sequencing Reveals How the Aryl Hydrocarbon Receptor Shapes Cellular Differentiation Potency in the Mouse Colon. Cancer Prev Res (Phila) 2021; 15:17-28. [PMID: 34815312 DOI: 10.1158/1940-6207.capr-21-0378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/18/2021] [Accepted: 11/16/2021] [Indexed: 11/16/2022]
Abstract
Despite recent progress recognizing the importance of aryl hydrocarbon receptor (Ahr)-dependent signaling in suppressing colon tumorigenesis, its role in regulating colonic crypt homeostasis remains unclear. To assess the effects of Ahr on intestinal epithelial cell heterogeneity and functional phenotypes, we utilized single-cell transcriptomics and advanced analytic strategies to generate a high-quality atlas for colonic intestinal crypts from wild-type and intestinal-specific Ahr knockout mice. Here we observed the promotive effects of Ahr deletion on Foxm1-regulated genes in crypt-associated canonical epithelial cell types and subtypes of goblet cells and deep crypt-secretory cells. We also show that intestinal Ahr deletion elevated single-cell entropy (a measure of differentiation potency or cell stemness) and RNA velocity length (a measure of the rate of cell differentiation) in noncycling and cycling Lgr5+ stem cells. In general, intercellular signaling cross-talk via soluble and membrane-bound factors was perturbed in Ahr-null colonocytes. Taken together, our single-cell RNA sequencing analyses provide new evidence of the molecular function of Ahr in modulating putative stem cell driver genes, cell potency lineage decisions, and cell-cell communication in vivo. PREVENTION RELEVANCE: Our mouse single-cell RNA sequencing analyses provide new evidence of the molecular function of Ahr in modulating colonic stemness and cell-cell communication in vivo. From a cancer prevention perspective, Ahr should be considered a therapeutic target to recalibrate remodeling of the intestinal stem cell niche.
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Affiliation(s)
- Yongjian Yang
- Department of Electrical & Computer Engineering, Texas A&M University, College Station, Texas
| | - Daniel Osorio
- Department of Veterinary Integrative Biosciences, Texas A&M University College of Veterinary Medicine and Biomedical Sciences, College Station, Texas
| | - Laurie A Davidson
- Department of Nutrition, Texas A&M University, College Station, Texas.,Program in Integrative Nutrition & Complex Diseases, Texas A&M University, College Station, Texas
| | - Huajun Han
- Program in Integrative Nutrition & Complex Diseases, Texas A&M University, College Station, Texas.,Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas
| | - Destiny A Mullens
- Program in Integrative Nutrition & Complex Diseases, Texas A&M University, College Station, Texas.,Department of Veterinary Pathobiology, Texas A&M University College of Veterinary Medicine and Biomedical Sciences, College Station, Texas
| | - Arul Jayaraman
- Department of Chemical Engineering, Texas A&M University, College Station, Texas
| | - Stephen Safe
- Department of Veterinary Physiology & Pharmacology, Texas A&M University College of Veterinary Medicine and Biomedical Sciences, College Station, Texas
| | - Ivan Ivanov
- Department of Veterinary Pathobiology, Texas A&M University College of Veterinary Medicine and Biomedical Sciences, College Station, Texas
| | - James J Cai
- Department of Electrical & Computer Engineering, Texas A&M University, College Station, Texas.,Department of Veterinary Integrative Biosciences, Texas A&M University College of Veterinary Medicine and Biomedical Sciences, College Station, Texas
| | - Robert S Chapkin
- Department of Nutrition, Texas A&M University, College Station, Texas. .,Program in Integrative Nutrition & Complex Diseases, Texas A&M University, College Station, Texas.,Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas
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12
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Han H, Safe S, Jayaraman A, Chapkin RS. Diet-Host-Microbiota Interactions Shape Aryl Hydrocarbon Receptor Ligand Production to Modulate Intestinal Homeostasis. Annu Rev Nutr 2021; 41:455-478. [PMID: 34633858 PMCID: PMC8667662 DOI: 10.1146/annurev-nutr-043020-090050] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated basic-helix-loop-helix transcription factor that binds structurally diverse ligands and senses cues from environmental toxicants and physiologically relevant dietary/microbiota-derived ligands. The AhR is an ancient conserved protein and is widely expressed across different tissues in vertebrates and invertebrates. AhR signaling mediates a wide range of cellular functions in a ligand-, cell type-, species-, and context-specific manner. Dysregulation of AhR signaling is linked to many developmental defects and chronic diseases. In this review, we discuss the emerging role of AhR signaling in mediating bidirectional host-microbiome interactions. We also consider evidence showing the potential for the dietary/microbial enhancement ofhealth-promoting AhR ligands to improve clinical pathway management in the context of inflammatory bowel diseases and colon tumorigenesis.
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Affiliation(s)
- Huajun Han
- Program in Integrative Nutrition and Complex Diseases and Department of Nutrition, Texas A&M University, College Station, Texas 77843, USA;
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843, USA
| | - Stephen Safe
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843, USA
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas 77843, USA
| | - Arul Jayaraman
- Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - Robert S Chapkin
- Program in Integrative Nutrition and Complex Diseases and Department of Nutrition, Texas A&M University, College Station, Texas 77843, USA;
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843, USA
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13
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Chapkin RS, Davidson LA, Park H, Jin UH, Fan YY, Cheng Y, Hensel ME, Landrock KK, Allred C, Menon R, Klemashevich C, Jayaraman A, Safe S. Role of the Aryl Hydrocarbon Receptor (AhR) in Mediating the Effects of Coffee in the Colon. Mol Nutr Food Res 2021; 65:e2100539. [PMID: 34406707 DOI: 10.1002/mnfr.202100539] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/26/2021] [Indexed: 12/14/2022]
Abstract
SCOPE This study investigates the mechanism of action and functional effects of coffee extracts in colonic cells, on intestinal stem cell growth, and inhibition of dextran sodium sulfate (DSS)-induced intestinal barrier damage in mice. METHODS AND RESULTS Aqueous coffee extracts induced Ah receptor (AhR) -responsive CYP1A1, CYP1B1, and UGT1A1 gene expression in colon-derived Caco2 and YAMC cells. Tissue-specific AhR knockout (AhRf/f x Lgr5-GFP-CreERT2 x Villin-Cre), wild-type (Lgr5-CreERT2 x Villin-Cre) mice are sources of stem cell enriched organoids and both coffee extracts and norharman, an AhR-active component of these extracts inhibited stem cell growth. Coffee extracts also inhibit DSS-induced damage to intestinal barrier function and DSS-induced mucosal inflammatory genes such as IL-6 and TGF-β1 in wild-type (AhR+/+ ) but not AhR-/- mice. In contrast, coffee does not exhibit protective effects in intestinal-specific AhR knockout mice. Coffee extracts also enhanced overall formation of AhR-active microbial metabolites. CONCLUSIONS In colon-derived cells and in the mouse intestine, coffee induced several AhR-dependent responses including gene expression, inhibition of intestinal stem cell-enriched organoid growth, and inhibition of DSS-induced intestinal barrier damage. We conclude that the anti-inflammatory effects of coffee in the intestine are due, in part, to activation of AhR signaling.
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Affiliation(s)
- Robert S Chapkin
- Departments of Nutrition and Biochemistry & Biophysics Texas A&M University, College Station, TX, 77843, USA
| | - Laurie A Davidson
- Departments of Nutrition and Biochemistry & Biophysics Texas A&M University, College Station, TX, 77843, USA
| | - Hyejin Park
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843, USA
| | - Un-Ho Jin
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843, USA
| | - Yang-Yi Fan
- Departments of Nutrition and Biochemistry & Biophysics Texas A&M University, College Station, TX, 77843, USA
| | - Yating Cheng
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843, USA
| | - Martha E Hensel
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, 77843, USA
| | - Kerstin K Landrock
- Departments of Nutrition and Biochemistry & Biophysics Texas A&M University, College Station, TX, 77843, USA
| | - Clinton Allred
- Departments of Nutrition and Biochemistry & Biophysics Texas A&M University, College Station, TX, 77843, USA
| | - Rani Menon
- Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Cory Klemashevich
- Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Arul Jayaraman
- Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Stephen Safe
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843, USA
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14
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Ala M. Tryptophan metabolites modulate inflammatory bowel disease and colorectal cancer by affecting immune system. Int Rev Immunol 2021; 41:326-345. [PMID: 34289794 DOI: 10.1080/08830185.2021.1954638] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Tryptophan is an essential amino acid, going through three different metabolic pathways in the intestines. Indole pathway in the gut microbiota, serotonin system in the enterochromaffin cells and kynurenine pathway in the immune cells and intestinal lining are the three arms of tryptophan metabolism in the intestines. Clinical, in vivo and in vitro studies showed that each one of these arms has a significant impact on IBD. This review explains how different metabolites of tryptophan are involved in the pathophysiology of IBD and colorectal cancer, as a major complication of IBD. Indole metabolites alleviate colitis and protect against colorectal cancer while serotonin arm follows a more complicated and receptor-specific pattern. Indole metabolites and kynurenine interact with aryl hydrocarbon receptor (AHR) to induce T regulatory cells differentiation, confine Th17 and Th1 response and produce anti-inflammatory mediators. Kynurenine decreases tumor-infiltrating CD8+ cells and mediates tumor cells immune evasion. Serotonin system also increases colorectal cancer cells proliferation and metastasis while, indole metabolites can profoundly decrease colorectal cancer growth. Targeted therapy for tryptophan metabolites may improve the management of IBD and colorectal cancer, e.g. supplementation of indole metabolites such as indole-3-carbinol (I3C), inhibition of kynurenine monooxygenase (KMO) and selective stimulation or inhibition of specific serotonergic receptors can mitigate colitis. Furthermore, it will be explained how indole metabolites supplementation, inhibition of indoleamine 2,3-dioxygenase 1 (IDO1), KMO and serotonin receptors can protect against colorectal cancer. Additionally, extensive molecular interactions between tryptophan metabolites and intracellular signaling pathways will be thoroughly discussed.
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Affiliation(s)
- Moein Ala
- School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
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15
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Yang Y, Chan WK. Glycogen Synthase Kinase 3 Beta Regulates the Human Aryl Hydrocarbon Receptor Cellular Content and Activity. Int J Mol Sci 2021; 22:ijms22116097. [PMID: 34198826 PMCID: PMC8201391 DOI: 10.3390/ijms22116097] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 12/21/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a cytosolic receptor which is involved in diverse cellular events in humans. The most well-characterized function of AHR is its ability to upregulate gene transcription after exposure to its ligands, such as environmental toxicants, dietary antioxidants, drugs, and endogenous ligands. The cellular content of AHR is partly controlled by its degradation via the ubiquitin–proteasome system and the lysosome-dependent autophagy. We used human cervical cancer (HeLa) cells to investigate how AHR undergoes protein degradation and how its activity is modulated. Since the glycogen synthase kinase 3 beta (GSK3β)-mediated phosphorylation can trigger protein degradation and substrates of GSK3β contain stretches of serine/threonine residues which can be found in AHR, we examined whether degradation and activity of AHR can be controlled by GSK3β. We observed that AHR undergoes the GSK3β-dependent, LC3-mediated lysosomal degradation without ligand treatment. The AHR can be phosphorylated in a GSK3β-dependent manner at three putative sites (S436/S440/S444, S689/S693/T697, and S723/S727/T731), which leads to lysosomal degradation of the AHR protein. Inhibition of the GSK3β activity suppresses the ligand-activated transcription of an AHR target gene in HeLa, human liver cancer (Hep3B), and human breast cancer (MCF-7) cells. Collectively, our findings support that phosphorylation of AHR by GSK3β is essential for the optimal activation of its target gene transcription and this phosphorylation may partake as an “off” switch by subjecting the receptor to lysosomal degradation.
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16
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Grifka-Walk HM, Jenkins BR, Kominsky DJ. Amino Acid Trp: The Far Out Impacts of Host and Commensal Tryptophan Metabolism. Front Immunol 2021; 12:653208. [PMID: 34149693 PMCID: PMC8213022 DOI: 10.3389/fimmu.2021.653208] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022] Open
Abstract
Tryptophan (Trp) is an essential amino acid primarily derived from the diet for use by the host for protein synthesis. The intestinal tract is lined with cells, both host and microbial, that uptake and metabolize Trp to also generate important signaling molecules. Serotonin (5-HT), kynurenine and its downstream metabolites, and to a lesser extent other neurotransmitters are generated by the host to signal onto host receptors and elicit physiological effects. 5-HT production by neurons in the CNS regulates sleep, mood, and appetite; 5-HT production in the intestinal tract by enterochromaffin cells regulates gastric motility and inflammation in the periphery. Kynurenine can signal onto the aryl hydrocarbon receptor (AHR) to elicit pleiotropic responses from several cell types including epithelial and immune cells, or can be further metabolized into bioactive molecules to influence neurodegenerative disease. There is a remarkable amount of cross-talk with the microbiome with regard to tryptophan metabolites as well. The gut microbiome can regulate the production of host tryptophan metabolites and can use dietary or recycled trp to generate bioactive metabolites themselves. Trp derivatives like indole are able to signal onto xenobiotic receptors, including AHR, to elicit tolerogenic effects. Here, we review studies that demonstrate that tryptophan represents a key intra-kingdom signaling molecule.
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Affiliation(s)
- Heather M Grifka-Walk
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Brittany R Jenkins
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | - Douglas J Kominsky
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
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17
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Han H, Davidson LA, Hensel M, Yoon G, Landrock K, Allred C, Jayaraman A, Ivanov I, Safe SH, Chapkin RS. Loss of Aryl Hydrocarbon Receptor Promotes Colon Tumorigenesis in ApcS580/+; KrasG12D/+ Mice. Mol Cancer Res 2021; 19:771-783. [PMID: 33495399 DOI: 10.1158/1541-7786.mcr-20-0789] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/03/2020] [Accepted: 01/14/2021] [Indexed: 11/16/2022]
Abstract
The mutational genetic landscape of colorectal cancer has been extensively characterized; however, the ability of "cooperation response genes" to modulate the function of cancer "driver" genes remains largely unknown. In this study, we investigate the role of aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, in modulating oncogenic cues in the colon. We show that intestinal epithelial cell-targeted AhR knockout (KO) promotes the expansion and clonogenic capacity of colonic stem/progenitor cells harboring ApcS580/+; KrasG12D/+ mutations by upregulating Wnt signaling. The loss of AhR in the gut epithelium increased cell proliferation, reduced mouse survival rate, and promoted cecum and colon tumorigenesis in mice. Mechanistically, the antagonism of Wnt signaling induced by Lgr5 haploinsufficiency attenuated the effects of AhR KO on cecum and colon tumorigenesis. IMPLICATIONS: Our findings reveal that AhR signaling plays a protective role in genetically induced colon tumorigenesis at least by suppressing Wnt signaling and provides rationale for the AhR as a therapeutic target for cancer prevention and treatment.
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Affiliation(s)
- Huajun Han
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas.,Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas
| | - Laurie A Davidson
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas.,Department of Nutrition, Texas A&M University, College Station, Texas
| | - Martha Hensel
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas
| | - Grace Yoon
- Department of Statistics, Texas A&M University, College Station, Texas
| | - Kerstin Landrock
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas.,Department of Nutrition, Texas A&M University, College Station, Texas
| | - Clinton Allred
- Department of Nutrition, Texas A&M University, College Station, Texas
| | - Arul Jayaraman
- Department of Chemical Engineering, Texas A&M University, College Station, Texas
| | - Ivan Ivanov
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas.,Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas
| | - Stephen H Safe
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas
| | - Robert S Chapkin
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, Texas. .,Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas.,Department of Nutrition, Texas A&M University, College Station, Texas
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18
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AhR and Cancer: From Gene Profiling to Targeted Therapy. Int J Mol Sci 2021; 22:ijms22020752. [PMID: 33451095 PMCID: PMC7828536 DOI: 10.3390/ijms22020752] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/04/2021] [Accepted: 01/08/2021] [Indexed: 02/08/2023] Open
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that has been shown to be an essential regulator of a broad spectrum of biological activities required for maintaining the body’s vital functions. AhR also plays a critical role in tumorigenesis. Its role in cancer is complex, encompassing both pro- and anti-tumorigenic activities. Its level of expression and activity are specific to each tumor and patient, increasing the difficulty of understanding the activating or inhibiting roles of AhR ligands. We explored the role of AhR in tumor cell lines and patients using genomic data sets and discuss the extent to which AhR can be considered as a therapeutic target.
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19
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Han H, Jayaraman A, Safe S, Chapkin RS. Targeting the aryl hydrocarbon receptor in stem cells to improve the use of food as medicine. CURRENT STEM CELL REPORTS 2021; 6:109-118. [PMID: 34395177 DOI: 10.1007/s40778-020-00184-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Purpose of review Intestinal stem cells, the most rapidly proliferating adult stem cells, are exquisitely sensitive to extrinsic dietary factors. Uncontrolled regulation of intestinal stem cells is closely linked to colon tumorigenesis. This review focuses on how dietary and microbial derived cues regulate intestinal stem cell functionality and colon tumorigenesis in mouse models by targeting the aryl hydrocarbon receptor (AhR). Recent findings AhR, a ligand activated transcription factor, can integrate environmental, dietary and microbial cues to modulate intestinal stem cell proliferation, differentiation and their microenvironment, affecting colon cancer risk. Modulation of AhR activity is associated with many chronic diseases, including inflammatory bowel diseases where AhR expression is protective. Summary AhR signaling controls the maintenance and differentiation of intestinal stem cells, influences local niche factors, and plays a protective role in colon tumorigenesis. Mounting evidence suggests that extrinsic nutritional/dietary cues which modulate AhR signaling may be a promising approach to colon cancer chemoprevention.
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Affiliation(s)
- Huajun Han
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, 77843
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843
| | - Arul Jayaraman
- Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843
| | - Stephen Safe
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, 77843
| | - Robert S Chapkin
- Program in Integrative Nutrition and Complex Diseases, Texas A&M University, College Station, TX, 77843
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843
- Department of Nutrition, Texas A&M University, College Station, TX, 77843
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20
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Yang F, DeLuca JAA, Menon R, Garcia-Vilarato E, Callaway E, Landrock KK, Lee K, Safe SH, Chapkin RS, Allred CD, Jayaraman A. Effect of diet and intestinal AhR expression on fecal microbiome and metabolomic profiles. Microb Cell Fact 2020; 19:219. [PMID: 33256731 PMCID: PMC7708923 DOI: 10.1186/s12934-020-01463-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 10/28/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Diet, loss of aryl hydrocarbon receptor (AhR) expression and their modification of the gut microbiota community composition and its metabolites affect the development of colorectal cancer (CRC). However, the concordance between fecal microbiota composition and the fecal metabolome is poorly understood. Mice with specific AhR deletion (AhRKO) in intestinal epithelial cell and their wild-type littermates were fed a low-fat diet or a high-fat diet. Shifts in the fecal microbiome and metabolome associated with diet and loss of AhR expression were assessed. Microbiome and metabolome data were integrated to identify specific microbial taxa that contributed to the observed metabolite shifts. RESULTS Our analysis shows that diet has a more pronounced effect on mouse fecal microbiota composition than the impact of the loss of AhR. In contrast, metabolomic analysis showed that the loss of AhR in intestinal epithelial cells had a more pronounced effect on metabolite profile compared to diet. Integration analysis of microbiome and metabolome identified unclassified Clostridiales, unclassified Desulfovibrionaceae, and Akkermansia as key contributors to the synthesis and/or utilization of tryptophan metabolites. CONCLUSIONS Akkermansia are likely to contribute to the synthesis and/or degradation of tryptophan metabolites. Our study highlights the use of multi-omic analysis to investigate the relationship between the microbiome and metabolome and identifies possible taxa that can be targeted to manipulate the microbiome for CRC treatment.
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Affiliation(s)
- Fang Yang
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | | | - Rani Menon
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | | | - Evelyn Callaway
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | | | - Kyongbum Lee
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA, USA
| | - Stephen H Safe
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, USA
| | - Robert S Chapkin
- Department of Nutrition, Texas A&M University, College Station, TX, USA
| | - Clinton D Allred
- Department of Nutrition, Texas A&M University, College Station, TX, USA
| | - Arul Jayaraman
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA.
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA.
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21
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Mukherji R, Weinberg BA. The gut microbiome and potential implications for early-onset colorectal cancer. COLORECTAL CANCER 2020. [DOI: 10.2217/crc-2020-0007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recently, there has been an unexpected trend toward increased incidence of colorectal cancer in younger individuals, particularly distal colon and rectal cancer in those under age 50. There is evidence to suggest that the human gut microbiome may play a role in carcinogenesis. The microbiome is dynamic and varies with age, geography, ethnicity and diet. Certain bacteria such as Fusobacterium nucleatum have been implicated in the development of colorectal and other gastrointestinal cancers. Recent data suggest that bacteria can alter the inflammatory and immune environment, influencing carcinogenesis, lack of treatment response and prognosis. Studies to date focus on older patients. Because the microbiome varies with age, it could be a potential explanation for the rise in early-onset colorectal cancer.
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Affiliation(s)
- Reetu Mukherji
- Ruesch Center for the Cure of Gastrointestinal Cancers, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20057 USA
| | - Benjamin A Weinberg
- Ruesch Center for the Cure of Gastrointestinal Cancers, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, 20057 USA
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