1
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Alafate W, Lv G, Zheng J, Cai H, Wu W, Yang Y, Du S, Zhou D, Wang P. Targeting ARNT attenuates chemoresistance through destabilizing p38α-MAPK signaling in glioblastoma. Cell Death Dis 2024; 15:366. [PMID: 38806469 PMCID: PMC11133443 DOI: 10.1038/s41419-024-06735-1] [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: 01/06/2024] [Revised: 05/07/2024] [Accepted: 05/08/2024] [Indexed: 05/30/2024]
Abstract
Glioblastoma (GBM) is the most aggressive and lethal brain tumor in adults. This study aimed to investigate the functional significance of aryl hydrocarbon receptor nuclear translocator (ARNT) in the pathogenesis of GBM. Analysis of public datasets revealed ARNT is upregulated in GBM tissues compared to lower grade gliomas or normal brain tissues. Higher ARNT expression correlated with the mesenchymal subtype and poorer survival in GBM patients. Silencing ARNT using lentiviral shRNAs attenuated the proliferative, invasive, and stem-like capabilities of GBM cell lines, while ARNT overexpression enhanced these malignant phenotypes. Single-cell RNA sequencing uncovered that ARNT is highly expressed in a stem-like subpopulation and is involved in regulating glycolysis, hypoxia response, and stress pathways. Mechanistic studies found ARNT activates p38 mitogen-activated protein kinase (MAPK) signaling to promote chemoresistance in GBM cells. Disrupting the ARNT/p38α protein interaction via the ARNT PAS-A domain restored temozolomide sensitivity. Overall, this study demonstrates ARNT functions as an oncogenic driver in GBM pathogenesis and represents a promising therapeutic target.
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Affiliation(s)
- Wahafu Alafate
- Department of Neurosurgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China.
| | - Gen Lv
- Department of Neurosurgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Jiantao Zheng
- Department of Neurosurgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Haiping Cai
- Department of Neurosurgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Wei Wu
- Department of Neurosurgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
- Center of Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Yong Yang
- Department of Neurosurgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Shichao Du
- Department of Neurosurgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Dong Zhou
- Department of Neurosurgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Peng Wang
- Department of Neurosurgery, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China.
- Department of Neurosurgery, Heyuan People's Hospital, Heyuan, China.
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2
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Opitz CA, Holfelder P, Prentzell MT, Trump S. The complex biology of aryl hydrocarbon receptor activation in cancer and beyond. Biochem Pharmacol 2023; 216:115798. [PMID: 37696456 PMCID: PMC10570930 DOI: 10.1016/j.bcp.2023.115798] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 09/13/2023]
Abstract
The aryl hydrocarbon receptor (AHR) signaling pathway is a complex regulatory network that plays a critical role in various biological processes, including cellular metabolism, development, and immune responses. The complexity of AHR signaling arises from multiple factors, including the diverse ligands that activate the receptor, the expression level of AHR itself, and its interaction with the AHR nuclear translocator (ARNT). Additionally, the AHR crosstalks with the AHR repressor (AHRR) or other transcription factors and signaling pathways and it can also mediate non-genomic effects. Finally, posttranslational modifications of the AHR and its interaction partners, epigenetic regulation of AHR and its target genes, as well as AHR-mediated induction of enzymes that degrade AHR-activating ligands may contribute to the context-specificity of AHR activation. Understanding the complexity of AHR signaling is crucial for deciphering its physiological and pathological roles and developing therapeutic strategies targeting this pathway. Ongoing research continues to unravel the intricacies of AHR signaling, shedding light on the regulatory mechanisms controlling its diverse functions.
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Affiliation(s)
- Christiane A Opitz
- German Cancer Research Center (DKFZ), Heidelberg, Division of Metabolic Crosstalk in Cancer and the German Cancer Consortium (DKTK), DKFZ Core Center Heidelberg, 69120 Heidelberg, Germany; Neurology Clinic and National Center for Tumor Diseases, 69120 Heidelberg, Germany.
| | - Pauline Holfelder
- German Cancer Research Center (DKFZ), Heidelberg, Division of Metabolic Crosstalk in Cancer and the German Cancer Consortium (DKTK), DKFZ Core Center Heidelberg, 69120 Heidelberg, Germany; Faculty of Bioscience, Heidelberg University, 69120 Heidelberg, Germany
| | - Mirja Tamara Prentzell
- German Cancer Research Center (DKFZ), Heidelberg, Division of Metabolic Crosstalk in Cancer and the German Cancer Consortium (DKTK), DKFZ Core Center Heidelberg, 69120 Heidelberg, Germany; Faculty of Bioscience, Heidelberg University, 69120 Heidelberg, Germany
| | - Saskia Trump
- Molecular Epidemiology Unit, Berlin Institute of Health at Charité and the German Cancer Consortium (DKTK), Partner Site Berlin, a partnership between DKFZ and Charité -Universitätsmedizin Berlin, 10117 Berlin, Germany
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3
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Elson D, Nguyen BD, Bernales S, Chakravarty S, Jang HS, Korjeff NA, Zhang Y, Wilferd SF, Castro DJ, Plaisier CL, Finlay D, Oshima RG, Kolluri SK. Induction of Aryl Hydrocarbon Receptor-Mediated Cancer Cell-Selective Apoptosis in Triple-Negative Breast Cancer Cells by a High-Affinity Benzimidazoisoquinoline. ACS Pharmacol Transl Sci 2023; 6:1028-1042. [PMID: 37470014 PMCID: PMC10353065 DOI: 10.1021/acsptsci.2c00253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Indexed: 07/21/2023]
Abstract
Triple-negative breast cancer (TNBC) remains a disease with a paucity of targeted treatment opportunities. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that is involved in a wide range of physiological processes, including the sensing of xenobiotics, immune function, development, and differentiation. Different small-molecule AhR ligands drive strikingly varied cellular and organismal responses. In certain cancers, AhR activation by select small molecules induces cell cycle arrest or apoptosis via activation of tumor-suppressive transcriptional programs. AhR is expressed in triple-negative breast cancers, presenting a tractable therapeutic opportunity. Here, we identify a novel ligand of the aryl hydrocarbon receptor that potently and selectively induces cell death in triple-negative breast cancer cells and TNBC stem cells via the AhR. Importantly, we found that this compound, Analog 523, exhibits minimal cytotoxicity against multiple normal human primary cells. Analog 523 represents a high-affinity AhR ligand with potential for future clinical translation as an anticancer agent.
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Affiliation(s)
- Daniel
J. Elson
- Cancer
Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, 97331, United States
| | - Bach D. Nguyen
- Cancer
Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, 97331, United States
| | - Sebastian Bernales
- Praxis
Biotech, San Francisco, California, 94158, United States
- Centro Ciencia
& Vida, Avda. Del
Valle Norte 725, Santiago, 8580702, Chile
| | | | - Hyo Sang Jang
- Cancer
Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, 97331, United States
| | - Nicholas A. Korjeff
- Cancer
Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, 97331, United States
| | - Yi Zhang
- Cancer
Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, 97331, United States
| | - Sierra F. Wilferd
- School
of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287, United States
| | - David J. Castro
- Sanford
Burnham Prebys Medical Discovery Institute, NCI Designated Cancer
Center, La Jolla, California, 92037, United States
- Oregon Health
& Science University, Portland, Oregon, 97239, United States
| | - Christopher L. Plaisier
- School
of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287, United States
| | - Darren Finlay
- Sanford
Burnham Prebys Medical Discovery Institute, NCI Designated Cancer
Center, La Jolla, California, 92037, United States
| | - Robert G. Oshima
- Sanford
Burnham Prebys Medical Discovery Institute, NCI Designated Cancer
Center, La Jolla, California, 92037, United States
| | - Siva K. Kolluri
- Cancer
Research Laboratory, Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon, 97331, United States
- Linus
Pauling Institute, Oregon State University, Corvallis, Oregon, 97331, United
States
- The
Pacific Northwest Center for Translational Environmental Health Research, Oregon State University, Corvallis, Oregon, 97331, United States
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4
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Zeng J, Chen J, Li M, Zhong C, Liu Z, Wang Y, Li Y, Jiang F, Fang S, Zhong W. Integrated high-throughput analysis identifies super enhancers in metastatic castration-resistant prostate cancer. Front Pharmacol 2023; 14:1191129. [PMID: 37292153 PMCID: PMC10244677 DOI: 10.3389/fphar.2023.1191129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 04/25/2023] [Indexed: 06/10/2023] Open
Abstract
Background: Metastatic castration-resistant prostate cancer (mCRPC) is a highly aggressive stage of prostate cancer, and non-mutational epigenetic reprogramming plays a critical role in its progression. Super enhancers (SE), epigenetic elements, are involved in multiple tumor-promoting signaling pathways. However, the SE-mediated mechanism in mCRPC remains unclear. Methods: SE-associated genes and transcription factors were identified from a cell line (C4-2B) of mCRPC by the CUT&Tag assay. Differentially expressed genes (DEGs) between mCRPC and primary prostate cancer (PCa) samples in the GSE35988 dataset were identified. What's more, a recurrence risk prediction model was constructed based on the overlapping genes (termed SE-associated DEGs). To confirm the key SE-associated DEGs, BET inhibitor JQ1 was applied to cells to block SE-mediated transcription. Finally, single-cell analysis was performed to visualize cell subpopulations expressing the key SE-associated DEGs. Results: Nine human TFs, 867 SE-associated genes and 5417 DEGs were identified. 142 overlapping SE-associated DEGs showed excellent performance in recurrence prediction. Time-dependent receiver operating characteristic (ROC) curve analysis showed strong predictive power at 1 year (0.80), 3 years (0.85), and 5 years (0.88). The efficacy of his performance has also been validated in external datasets. In addition, FKBP5 activity was significantly inhibited by JQ1. Conclusion: We present a landscape of SE and their associated genes in mCPRC, and discuss the potential clinical implications of these findings in terms of their translation to the clinic.
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Affiliation(s)
- Jie Zeng
- Department of Urology, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
| | - Jiahong Chen
- Department of Urology, Huizhou Municipal Central Hospital, Huizhou, Guangdong, China
| | - Maozhang Li
- Department of Urology, Huizhou Municipal Central Hospital, Huizhou, Guangdong, China
| | - Chuanfan Zhong
- Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Zezhen Liu
- Department of Urology, Minimally Invasive Surgery Center, The First Affiliated Hospital of Guangzhou Medical University, and Guangdong Key Laboratory of Urology, Guangzhou, Guangdong, China
| | - Yan Wang
- Department of Urology, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
| | - Yuejiao Li
- Department of Urology, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
| | - Funeng Jiang
- Department of Urology, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
| | - Shumin Fang
- Department of Urology, Huizhou Municipal Central Hospital, Huizhou, Guangdong, China
| | - Weide Zhong
- Department of Urology, The Second Affiliated Hospital, School of Medicine, South China University of Technology, Guangzhou, Guangdong, China
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5
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Ceranski AK, Carreño-Gonzalez MJ, Ehlers AC, Colombo MV, Cidre-Aranaz F, Grünewald TGP. Hypoxia and HIFs in Ewing sarcoma: new perspectives on a multi-facetted relationship. Mol Cancer 2023; 22:49. [PMID: 36915100 PMCID: PMC10010019 DOI: 10.1186/s12943-023-01750-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 02/20/2023] [Indexed: 03/16/2023] Open
Abstract
Hypoxia develops during the growth of solid tumors and influences tumoral activity in multiple ways. Low oxygen tension is also present in the bone microenvironment where Ewing sarcoma (EwS) - a highly aggressive pediatric cancer - mainly arises. Hypoxia inducible factor 1 subunit alpha (HIF-1-a) is the principal molecular mediator of the hypoxic response in cancer whereas EWSR1::FLI1 constitutes the oncogenic driver of EwS. Interaction of the two proteins has been shown in EwS. Although a growing body of studies investigated hypoxia and HIFs in EwS, their precise role for EwS pathophysiology is not clarified to date. This review summarizes and structures recent findings demonstrating that hypoxia and HIFs play a role in EwS at multiple levels. We propose to view hypoxia and HIFs as independent protagonists in the story of EwS and give a perspective on their potential clinical relevance as prognostic markers and therapeutic targets in EwS treatment.
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Affiliation(s)
- A Katharina Ceranski
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany.,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Martha J Carreño-Gonzalez
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany.,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Anna C Ehlers
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany.,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Maria Vittoria Colombo
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany.,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,Regenerative Medicine Technologies Laboratory, Laboratories for Translational Research (LRT), Ente Ospedaliero Cantonale (EOC), Via F. Chiesa 5, CH-6500, Bellinzona, Switzerland.,Department of Surgery, Service of Orthopaedics and Traumatology, EOC, Lugano, Switzerland.,Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico Di Milano, Via Mancinelli 7, 20131, Milan, Italy
| | - Florencia Cidre-Aranaz
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany.,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Thomas G P Grünewald
- Hopp-Children's Cancer Center (KiTZ), Heidelberg, Germany. .,Division of Translational Pediatric Sarcoma Research (B410), German Cancer Research Center (DKFZ), German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany. .,Institute of Pathology, Heidelberg University Hospital, Heidelberg, Germany.
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6
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Edwards HE, Gorelick DA. The evolution and structure/function of bHLH-PAS transcription factor family. Biochem Soc Trans 2022; 50:1227-1243. [PMID: 35695677 PMCID: PMC10584024 DOI: 10.1042/bst20211225] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 02/06/2023]
Abstract
Proteins that contain basic helix-loop-helix (bHLH) and Per-Arnt-Sim motifs (PAS) function as transcription factors. bHLH-PAS proteins exhibit essential and diverse functions throughout the body, from cell specification and differentiation in embryonic development to the proper function of organs like the brain and liver in adulthood. bHLH-PAS proteins are divided into two classes, which form heterodimers to regulate transcription. Class I bHLH-PAS proteins are typically activated in response to specific stimuli, while class II proteins are expressed more ubiquitously. Here, we discuss the general structure and functions of bHLH-PAS proteins throughout the animal kingdom, including family members that do not fit neatly into the class I-class II organization. We review heterodimerization between class I and class II bHLH-PAS proteins, binding partner selectivity and functional redundancy. Finally, we discuss the evolution of bHLH-PAS proteins, and why a class I protein essential for cardiovascular development in vertebrates like chicken and fish is absent from mammals.
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Affiliation(s)
- Hailey E Edwards
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, U.S.A
| | - Daniel A Gorelick
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, U.S.A
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7
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Alternative Splicing of the Aryl Hydrocarbon Receptor Nuclear Translocator (ARNT) Is Regulated by RBFOX2 in Lymphoid Malignancies. Mol Cell Biol 2022; 42:e0050321. [PMID: 35404107 PMCID: PMC9119065 DOI: 10.1128/mcb.00503-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Aberrant alternative splicing (AS) of pre-mRNAs promotes the development and proliferation of cancerous cells. Accordingly, we had previously observed higher levels of the aryl hydrocarbon receptor nuclear translocator (ARNT) spliced variant isoform 1 in human lymphoid malignancies compared to that in normal lymphoid cells, which is a consequence of increased inclusion of alternative exon 5. ARNT is a transcription factor that has been implicated in the survival of various cancers. Notably, we found that ARNT isoform 1 promoted the growth and survival of lymphoid malignancies, but the regulatory mechanism controlling ARNT AS is unclear. Here, we report cis- and trans-regulatory elements which are important for the inclusion of ARNT exon 5. Specifically, we identified recognition motifs for the RNA-binding protein RBFOX2, which are required for RBFOX2-mediated exon 5 inclusion. RBFOX2 upregulation was observed in lymphoid malignancies, correlating with the observed increase in ARNT exon 5 inclusion. Moreover, suppression of RBFOX2 significantly reduced ARNT isoform 1 levels and cell growth. These observations reveal RBFOX2 as a critical regulator of ARNT AS in lymphoid malignancies and suggest that blocking the ARNT-specific RBFOX2 motifs to decrease ARNT isoform 1 levels is a viable option for targeting the growth of lymphoid malignancies.
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8
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AhR promotes phosphorylation of ARNT isoform 1 in human T cell malignancies as a switch for optimal AhR activity. Proc Natl Acad Sci U S A 2022; 119:e2114336119. [PMID: 35290121 PMCID: PMC8944900 DOI: 10.1073/pnas.2114336119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The aryl hydrocarbon receptor nuclear translocator (ARNT) is a transcription factor present in immune cells as a long and short isoform, referred to as isoforms 1 and 3, respectively. However, investigation into potential ARNT isoform–specific immune functions is lacking despite the well-established heterodimerization requirement of ARNT with, and for the activity of, the aryl hydrocarbon receptor (AhR), a critical mediator of immune homeostasis. Here, using global and targeted transcriptomics analyses, we show that the relative ARNT isoform 1:3 ratio in human T cell lymphoma cells dictates the amplitude and direction of AhR target gene regulation. Specifically, shifting the ARNT isoform 1:3 ratio lower by suppressing isoform 1 enhances, or higher by suppressing isoform 3 abrogates, AhR responsiveness to ligand activation through preprograming a cellular genetic background that directs explicit gene expression patterns. Moreover, the fluctuations in gene expression patterns that accompany a decrease or increase in the ARNT isoform 1:3 ratio are associated with inflammation or immunosuppression, respectively. Molecular studies identified the unique casein kinase 2 (CK2) phosphorylation site within isoform 1 as an essential parameter to the mechanism of ARNT isoform–specific regulation of AhR signaling. Notably, CK2-mediated phosphorylation of ARNT isoform 1 is dependent on ligand-induced AhR nuclear translocation and is required for optimal AhR target gene regulation. These observations reveal ARNT as a central modulator of AhR activity predicated on the status of the ARNT isoform ratio and suggest that ARNT-based therapies are a viable option for tuning the immune system to target immune disorders.
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9
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Panebianco C, Trivieri N, Villani A, Terracciano F, Latiano TP, Potenza A, Perri F, Binda E, Pazienza V. Improving Gemcitabine Sensitivity in Pancreatic Cancer Cells by Restoring miRNA-217 Levels. Biomolecules 2021; 11:639. [PMID: 33925948 PMCID: PMC8146031 DOI: 10.3390/biom11050639] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/02/2021] [Accepted: 04/23/2021] [Indexed: 12/21/2022] Open
Abstract
Chemoresistance is a major problem in the therapeutic management of pancreatic cancer, concurring to poor clinical outcome. A number of mechanisms have been proposed to explain resistance to gemcitabine, a standard of care for this malignancy, among which is included aberrant miRNA expression. In the current study, we investigated the role of miR-217, which is strongly down-regulated in cancerous, compared to normal, pancreatic tissues or cells, in sensitizing human pancreatic cancer cell lines to this drug. The low expression of miR-217 in pancreatic cancer patients was confirmed in two gene expression datasets (GSE41372 and GSE60980), and the prognostic value of two target genes (ANLN and TRPS1), was estimated on clinical data from the Tumor Cancer Genome Atlas (TCGA). Transfecting miR-217 mimic in pancreatic cancer cells reduced viability, enhanced apoptosis, and affected cell cycle by promoting a S phase arrest in gemcitabine-treated cells. Moreover, in drug-exposed cells subjected to miR-217 forced expression, a down-regulation for several genes involved in cancer drug resistance was observed, many of which are cell cycle regulators, such as CCND1, CCNE1, CDK2, CDKN1A, CDKN1B, while others, such as ARNT, BRCA1, BRCA2, ELK1, EGFR, ERBB4, and RARA are involved in proliferation and cell cycle progression. Our results support the notion that miR-217 enhances pancreatic cancer sensitivity to gemcitabine, mainly impairing cell cycle progression.
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Affiliation(s)
- Concetta Panebianco
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy; (C.P.); (A.V.); (F.T.); (F.P.)
| | - Nadia Trivieri
- Cancer Stem Cell Unit, Institute for Stem-Cell Biology, Regenerative Medicine and Innovative Therapies (ISBReMIT), Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy;
| | - Annacandida Villani
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy; (C.P.); (A.V.); (F.T.); (F.P.)
| | - Fulvia Terracciano
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy; (C.P.); (A.V.); (F.T.); (F.P.)
| | - Tiziana Pia Latiano
- Oncology Unit Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy;
| | - Adele Potenza
- Dietetic and Clinical Nutrition Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy;
| | - Francesco Perri
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy; (C.P.); (A.V.); (F.T.); (F.P.)
| | - Elena Binda
- Cancer Stem Cell Unit, Institute for Stem-Cell Biology, Regenerative Medicine and Innovative Therapies (ISBReMIT), Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy;
| | - Valerio Pazienza
- Gastroenterology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy; (C.P.); (A.V.); (F.T.); (F.P.)
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10
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Gunin AG, Golubtzova NN, Kornilova NK. Aryl-Hydrocarbon Receptor Nuclear Translocator (ARNT) in Human Skin with Aging. ADVANCES IN GERONTOLOGY 2020. [DOI: 10.1134/s2079057020040086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Vogel CFA, Ishihara Y, Campbell CE, Kado SY, Nguyen-Chi A, Sweeney C, Pollet M, Haarmann-Stemmann T, Tuscano JM. A Protective Role of Aryl Hydrocarbon Receptor Repressor in Inflammation and Tumor Growth. Cancers (Basel) 2019; 11:cancers11050589. [PMID: 31035533 PMCID: PMC6563059 DOI: 10.3390/cancers11050589] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 04/19/2019] [Accepted: 04/25/2019] [Indexed: 01/02/2023] Open
Abstract
The aryl hydrocarbon receptor (AhR) is known for mediating the toxicity of environmental pollutants such as dioxins and numerous dioxin-like compounds, and is associated with the promotion of various malignancies, including lymphoma. The aryl hydrocarbon receptor repressor (AhRR), a ligand-independent, transcriptionally inactive AhR-like protein is known to repress AhR signaling through its ability to compete with the AhR for dimerization with the AhR nuclear translocator (ARNT). While AhRR effectively blocks AhR signaling, several aspects of the mechanism of AhRR’s functions are poorly understood, including suppression of inflammatory responses and its putative role as a tumor suppressor. In a transgenic mouse that overexpresses AhRR (AhRR Tg) we discovered that these mice suppress 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)- and inflammation-induced tumor growth after subcutaneous challenge of EL4 lymphoma cells. Using mouse embryonic fibroblasts (MEF) we found that AhRR overexpression suppresses the AhR-mediated anti-apoptotic response. The AhRR-mediated inhibition of apoptotic resistance was associated with a suppressed expression of interleukin (IL)-1β and cyclooxygenase (COX)-2, which was dependent on activation of protein kinase A (PKA) and the CAAT-enhancer-binding protein beta (C/EBPβ). These results provide mechanistic insights into the role of the AhRR to suppress inflammation and highlight the AhRR as a potential therapeutic target to suppress tumor growth.
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Affiliation(s)
- Christoph F A Vogel
- Department of Environmental Toxicology, University of California, One Shields Avenue, Davis, CA 95616, USA.
- Center for Health and the Environment, University of California, One Shields Avenue, Davis, CA 95616, USA.
| | - Yasuhiro Ishihara
- Center for Health and the Environment, University of California, One Shields Avenue, Davis, CA 95616, USA.
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8521, Japan.
| | - Claire E Campbell
- Center for Health and the Environment, University of California, One Shields Avenue, Davis, CA 95616, USA.
| | - Sarah Y Kado
- Center for Health and the Environment, University of California, One Shields Avenue, Davis, CA 95616, USA.
| | - Aimy Nguyen-Chi
- Center for Health and the Environment, University of California, One Shields Avenue, Davis, CA 95616, USA.
| | - Colleen Sweeney
- Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis, CA 95817, USA.
| | - Marius Pollet
- Center for Health and the Environment, University of California, One Shields Avenue, Davis, CA 95616, USA.
- Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany.
| | | | - Joseph M Tuscano
- Division of Hematology & Oncology, Department of Internal Medicine, University of California Davis Comprehensive Cancer Center, Sacramento, CA 95817, USA.
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12
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Abstract
Cells respond to hypoxia by shifting cellular processes from general housekeeping functions to activating specialized hypoxia-response pathways. Oxygen plays an important role in generating ATP to maintain a productive rate of protein synthesis in normoxia. In hypoxia, the rate of the canonical protein synthesis pathway is significantly slowed and impaired due to limited ATP availability, necessitating an alternative mechanism to mediate protein synthesis and facilitate adaptation. Hypoxia adaptation is largely mediated by hypoxia-inducible factors (HIFs). While HIFs are well known for their transcriptional functions, they also play imperative roles in translation to mediate hypoxic protein synthesis. Such adaptations to hypoxia are often hyperactive in solid tumors, contributing to the expression of cancer hallmarks, including treatment resistance. The current literature on protein synthesis in hypoxia is reviewed here, inclusive of hypoxia-specific mRNA selection to translation termination. Current HIF targeting therapies are also discussed as are the opportunities involved with targeting hypoxia specific protein synthesis pathways.
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Affiliation(s)
- Nancy T Chee
- Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Avenue, Miami, FL, 33136, USA
| | - Ines Lohse
- Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Avenue, Miami, FL, 33136, USA
| | - Shaun P Brothers
- Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Avenue, Miami, FL, 33136, USA.
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13
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Knutsen HK, Alexander J, Barregård L, Bignami M, Brüschweiler B, Ceccatelli S, Cottrill B, Dinovi M, Edler L, Grasl-Kraupp B, Hogstrand C, Nebbia CS, Oswald IP, Petersen A, Rose M, Roudot AC, Schwerdtle T, Vleminckx C, Vollmer G, Wallace H, Fürst P, Håkansson H, Halldorsson T, Lundebye AK, Pohjanvirta R, Rylander L, Smith A, van Loveren H, Waalkens-Berendsen I, Zeilmaker M, Binaglia M, Gómez Ruiz JÁ, Horváth Z, Christoph E, Ciccolallo L, Ramos Bordajandi L, Steinkellner H, Hoogenboom LR. Risk for animal and human health related to the presence of dioxins and dioxin-like PCBs in feed and food. EFSA J 2018; 16:e05333. [PMID: 32625737 PMCID: PMC7009407 DOI: 10.2903/j.efsa.2018.5333] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The European Commission asked EFSA for a scientific opinion on the risks for animal and human health related to the presence of dioxins (PCDD/Fs) and DL-PCBs in feed and food. The data from experimental animal and epidemiological studies were reviewed and it was decided to base the human risk assessment on effects observed in humans and to use animal data as supportive evidence. The critical effect was on semen quality, following pre- and postnatal exposure. The critical study showed a NOAEL of 7.0 pg WHO2005-TEQ/g fat in blood sampled at age 9 years based on PCDD/F-TEQs. No association was observed when including DL-PCB-TEQs. Using toxicokinetic modelling and taking into account the exposure from breastfeeding and a twofold higher intake during childhood, it was estimated that daily exposure in adolescents and adults should be below 0.25 pg TEQ/kg bw/day. The CONTAM Panel established a TWI of 2 pg TEQ/kg bw/week. With occurrence and consumption data from European countries, the mean and P95 intake of total TEQ by Adolescents, Adults, Elderly and Very Elderly varied between, respectively, 2.1 to 10.5, and 5.3 to 30.4 pg TEQ/kg bw/week, implying a considerable exceedance of the TWI. Toddlers and Other Children showed a higher exposure than older age groups, but this was accounted for when deriving the TWI. Exposure to PCDD/F-TEQ only was on average 2.4- and 2.7-fold lower for mean and P95 exposure than for total TEQ. PCDD/Fs and DL-PCBs are transferred to milk and eggs, and accumulate in fatty tissues and liver. Transfer rates and bioconcentration factors were identified for various species. The CONTAM Panel was not able to identify reference values in most farm and companion animals with the exception of NOAELs for mink, chicken and some fish species. The estimated exposure from feed for these species does not imply a risk.
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14
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Wu C, Yang T, Liu Y, Lu Y, Yang Y, Liu X, Liu X, Ye L, Sun Y, Wang X, Li Q, Yang P, Yu X, Gao S, Kumar S, Jin F, Dai Y, Li W. ARNT/HIF-1β links high-risk 1q21 gain and microenvironmental hypoxia to drug resistance and poor prognosis in multiple myeloma. Cancer Med 2018; 7:3899-3911. [PMID: 29926531 PMCID: PMC6089175 DOI: 10.1002/cam4.1596] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 04/25/2018] [Accepted: 05/14/2018] [Indexed: 02/05/2023] Open
Abstract
1q21 gain is a common cytogenetic abnormality featuring high‐risk multiple myeloma (HRMM). However, the molecular mechanism underlying the adverse prognostic effect of 1q21 gain remains largely unclear. Here, we report that ARNT/HIF‐1β, a 1q21 gene, is highly expressed in HRMM and induced by microenvironmental hypoxia, which confers drug resistance and correlates with inferior outcome. Analysis of the gene expression profile database revealed that ARNT expression was upregulated in MM and increased with disease progression or in HRMM subtypes (particularly 1q21 gain), while correlated to shorter overall survival. In a cohort of 40 MM patients, qPCR further validated that ARNT expression was higher in MM patients than normal donors. MM cells carrying 1q21 gain or acquired drug resistance displayed a robust increase in HIF‐1β protein level. Hypoxia induced HIF‐1β expression via a NF‐κB‐dependent process. Notably, HIF‐1β overexpression impaired bortezomib sensitivity, whereas shRNA knockdown of ARNT reversed hypoxia‐mediated drug resistance. Together, these findings suggest that ARNT/HIF‐1β might represent a novel biomarker for risk stratification and prognosis of HRMM patients, as well as a potential therapeutic target for overcoming 1q21 gain‐ or microenvironment‐mediated and acquired drug resistance in MM.
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Affiliation(s)
- Chuan Wu
- Laboratory of Cancer Precision Medicine, The First Hospital of Jilin University, Changchun, Jilin, China.,Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Ting Yang
- Laboratory of Cancer Precision Medicine, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Yingmin Liu
- Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Yicheng Lu
- Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Yanping Yang
- Department of Hematology, Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Xiaobo Liu
- Laboratory of Cancer Precision Medicine, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Xuelian Liu
- Department of Hematology, Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Long Ye
- Laboratory of Cancer Precision Medicine, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Yue Sun
- Laboratory of Cancer Precision Medicine, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Xue Wang
- Laboratory of Cancer Precision Medicine, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Qingchao Li
- Laboratory of Cancer Precision Medicine, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Peiyu Yang
- Department of Hematology, Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Xiaoyuan Yu
- Department of Hematology, Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Sujun Gao
- Department of Hematology, Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Shaji Kumar
- Division of Hematology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Fengyan Jin
- Department of Hematology, Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Yun Dai
- Laboratory of Cancer Precision Medicine, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Wei Li
- Cancer Center, The First Hospital of Jilin University, Changchun, Jilin, China
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15
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Shen F, Guo Q, Hu Q, Zeng A, Wu W, Yan W, You Y. RelB, a good prognosis predictor, links cell-cycle and migration to glioma tumorigenesis. Oncol Lett 2018. [PMID: 29541209 PMCID: PMC5835853 DOI: 10.3892/ol.2018.7894] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Nuclear factor κB (NF-κB) exhibits an important role in inflammation and tumorigenesis. The key regulatory protein of the pathway, RELB Proto-Oncogene, NF-KB Subunit (relB), is overexpressed and associated with the pathogenesis of a variety of malignant tumors. However, the molecular features and clinical signature of relB expression in gliomas remains to be elucidated. The present study obtained the raw sequencing data of 325 glioma samples of all grades from the Chinese Glioma Genome Atlas (CGGA) database and human glioma cell line (LN229) from the Chinese Academy of Sciences cell bank. Cell proliferation, invasion and wound healing assays were used for functional annotation of relB. Western blot analysis was used for validating the protein expression of relB, matrix metalloproteinase (MMP)-2 and MMP-9 in a further 77 glioma samples. In Diffuse Glioma data, relB expression was associated with glioma grade, demonstrated a mesenchymal subtype preference and cell development association. The downregulation of relB expression inhibited glioma cell migration and invasion by regulating the MMPs in vitro. relB expression was independently associated with grade and prognosis of grade III and grade IV gliomas, suggesting that relB is a novel biomarker with therapeutic potential for predicting prognosis in glioma.
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Affiliation(s)
- Feng Shen
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.,Department of Oncology, People's Hospital of Taizhou, Taizhou, Jiangsu 225300, P.R. China
| | - Qing Guo
- Department of Oncology, People's Hospital of Taizhou, Taizhou, Jiangsu 225300, P.R. China
| | - Qi Hu
- Department of Neurosurgery, The First People's Hospital of Yueyang, Yueyang, Hunan 414000, P.R. China
| | - Ailiang Zeng
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Weining Wu
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Wei Yan
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
| | - Yongping You
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China
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16
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Identification of ARNT-regulated BIRC3 as the target factor in cadmium renal toxicity. Sci Rep 2017; 7:17287. [PMID: 29229987 PMCID: PMC5725491 DOI: 10.1038/s41598-017-17494-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 11/27/2017] [Indexed: 01/16/2023] Open
Abstract
Cadmium (Cd) is an environmental contaminant that exhibits renal toxicity. The target transcription factors involved in Cd renal toxicity are still unknown. In this study, we demonstrated that Cd decreased the activity of the ARNT transcription factor, and knockdown of ARNT significantly decreased the viability of human proximal tubular HK-2 cells. Microarray analysis in ARNT knockdown cells revealed a decrease in the expression of a number of genes, including a known apoptosis inhibitor, BIRC3, whose gene and protein expression level was also decreased by Cd treatment. Although the BIRC family consists of 8 members, Cd suppressed only BIRC3 gene expression. BIRC3 is known to suppress apoptosis through the inhibition effect on caspase-3. Knockdown of BIRC3 by siRNA as well as Cd treatment increased the level of active caspase-3. Moreover, knockdown of BIRC3 not only triggered cell toxicity and apoptosis but also strengthened Cd toxicity in HK-2 cells. Meanwhile, the activation of caspase-3 by suppression of BIRC3 gene expression was mostly specific to Cd and to proximal tubular cells. These results suggest that Cd induces apoptosis through the inhibition of ARNT-regulated BIRC3 in human proximal tubular cells.
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17
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Mechanisms underlying the antiproliferative effects of a series of quinoxaline-derived chalcones. Sci Rep 2017; 7:15850. [PMID: 29158524 PMCID: PMC5696528 DOI: 10.1038/s41598-017-16199-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 11/09/2017] [Indexed: 12/26/2022] Open
Abstract
The present study aimed to characterize the effects of quinoxaline-derived chalcones, designed on the basis of the selective PI3Kγ inhibitor AS605240, in oral cancer cells. Three lead compounds, namely N9, N17 and N23, were selected from a series of 20 quinoxaline-derived chalcones, based on an initial screening using human and rat squamous cell carcinoma lineages, representing compounds with at least one methoxy radical at the A-ring. The selected chalcones, mainly N9 and N17, displayed marked antiproliferative effects, via apoptosis and autophagy induction, with an increase of sub-G1 population and Akt inhibition. The three chalcones displayed marked in vitro antitumor effects in different protocols with standard chemotherapy drugs, with acceptable toxicity on normal cells. There was no growth retrieval, after exposure to chalcone N9 alone, in a long-term assay to determine the cumulative population doubling (CPD) of human oral cancer cells. A PCR array evaluating 168 genes related to cancer and inflammation, demonstrated striking actions for N9, which altered the expression of 74 genes. Altogether, our results point out quinoxalinic chalcones, mainly N9, as potential strategies for oral cancer treatment.
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18
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Gao WQ, Ma J, Sun LL, Li Q, Zhu RY, Jin J. Paclitaxel-mediated human aryl hydrocarbon receptor mRNA translation by an internal ribosomal entry site-dependent mechanism. Oncol Rep 2017; 38:3211-3219. [PMID: 29048649 DOI: 10.3892/or.2017.5958] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 05/02/2017] [Indexed: 11/06/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that is best known in mediating the toxicities of dioxins and dioxin-like compounds. AHR is activated by a variety of endogenous ligands and participating in tumor development. Thus, it will provide a new approach for cancer prevention and treatment to study the translation mechanism of AHR in tumor cells. In this study, we show that the 5'-untranslated region (UTR) of AHR mRNA contains an internal ribosome entry site (IRES). After mapping the entire AHR 5'-UTR, we determined that the full-length 5'-UTR is indispensable for the highest IRES activity. Interestingly, we found that AHR expression is induced in ovarian (A2780), breast (MDA-MB231), hepatic (Bel7402) and colorectal cancer cells (SW620) by chemotherapeutic drug paclitaxel (PTX) through IRES-dependent translation mechanism. Moreover, IRES activity is increased in the PTX-resistant ovarian cancer cells in which AHR protein expression was also enhanced. These results strongly suggest an important role for AHR IRES-dependent translation mechanism in cancer cell response to paclitaxel treatment.
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Affiliation(s)
- Wen-Qing Gao
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Jing Ma
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Liu-Liu Sun
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Qi Li
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Rui-Yu Zhu
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
| | - Jian Jin
- Laboratory of Molecular Pharmacology, School of Pharmaceutical Sciences, Jiangnan University, Wuxi, Jiangsu 214122, P.R. China
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19
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Vogel CFA, Haarmann-Stemmann T. The aryl hydrocarbon receptor repressor - More than a simple feedback inhibitor of AhR signaling: Clues for its role in inflammation and cancer. CURRENT OPINION IN TOXICOLOGY 2017; 2:109-119. [PMID: 28971163 DOI: 10.1016/j.cotox.2017.02.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The aryl hydrocarbon receptor repressor (AhRR) was first described as a specific competitive repressor of aryl hydrocarbon receptor (AhR) activity based on its ability to dimerize with the AhR nuclear translocator (ARNT) and through direct competition of AhR/ARNT and AhRR/ARNT complexes for binding to dioxin-responsive elements (DREs). Like AhR, AhRR belongs to the basic Helix-Loop-Helix/Per-ARNT-Sim (bHLH/PAS) protein family but lacks functional ligand-binding and transactivation domains. Transient transfection experiments with ARNT and AhRR mutants examining the inhibitory mechanism of AhRR suggested a more complex mechanism than the simple mechanism of negative feedback through sequestration of ARNT to regulate AhR signaling. Recently, AhRR has been shown to act as a tumor suppressor gene in several types of cancer cells. Furthermore, epidemiological studies have found epigenetic changes and silencing of AhRR associated with exposure to cigarette smoke and cancer development. Additional studies from our laboratories have demonstrated that AhRR represses other signaling pathways including NF-κB and is capable of regulating inflammatory responses. A better understanding of the regulatory mechanisms of AhRR in AhR signaling and adverse outcome pathways leading to deregulated inflammatory responses contributing to tumor promotion and other adverse health effects is expected from future studies. This review article summarizes the characteristics of AhRR as an inhibitor of AhR activity and highlights more recent findings pointing out the role of AhRR in inflammation and tumorigenesis.
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Affiliation(s)
- Christoph F A Vogel
- Department of Environmental Toxicology and Center for Health and the Environment, University of California, Davis, CA 95616, USA
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