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Ochieng J, Nangami GN, Ogunkua O, Miousse IR, Koturbash I, Odero-Marah V, McCawley LJ, Nangia-Makker P, Ahmed N, Luqmani Y, Chen Z, Papagerakis S, Wolf GT, Dong C, Zhou BP, Brown DG, Colacci AM, Hamid RA, Mondello C, Raju J, Ryan EP, Woodrick J, Scovassi AI, Singh N, Vaccari M, Roy R, Forte S, Memeo L, Salem HK, Amedei A, Al-Temaimi R, Al-Mulla F, Bisson WH, Eltom SE. The impact of low-dose carcinogens and environmental disruptors on tissue invasion and metastasis. Carcinogenesis 2015; 36 Suppl 1:S128-59. [PMID: 26106135 DOI: 10.1093/carcin/bgv034] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The purpose of this review is to stimulate new ideas regarding low-dose environmental mixtures and carcinogens and their potential to promote invasion and metastasis. Whereas a number of chapters in this review are devoted to the role of low-dose environmental mixtures and carcinogens in the promotion of invasion and metastasis in specific tumors such as breast and prostate, the overarching theme is the role of low-dose carcinogens in the progression of cancer stem cells. It is becoming clearer that cancer stem cells in a tumor are the ones that assume invasive properties and colonize distant organs. Therefore, low-dose contaminants that trigger epithelial-mesenchymal transition, for example, in these cells are of particular interest in this review. This we hope will lead to the collaboration between scientists who have dedicated their professional life to the study of carcinogens and those whose interests are exclusively in the arena of tissue invasion and metastasis.
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Affiliation(s)
- Josiah Ochieng
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN 37208, USA, Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA, Department of Biology/Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA 30314, USA, Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA, Department of Pathology, Wayne State University, Detroit, MI 48201, USA, Department of Obstetrics and Gynecology, University of Melbourne, Melbourne, Victoria, Australia, Faculty of Pharmacy, Department of Pathology, Kuwait University, Safat 13110, Kuwait, Department of Otolaryngology, University of Michigan Medical College, Ann Arbor, MI 48109, USA, Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY 40506, USA, Department of Environmental and Radiological Health Sciences/Food Science and Human Nutrition, College of Veterinary Medicine and Biomedical Sciences, Colorado State University/Colorado School of Public Health, Fort Collins, CO 80523-1680, USA, Center for Environmental Carcinogenesis and Risk Assessment, Environmental Protection and Health Prevention Agency, Bologna 40126, Italy, Faculty of Medicine and Health Sciences, University Putra, Serdang, Selangor 43400, Malaysia, Istituto di Genetica Molecolare, CNR, via Abbiategrasso 207, 27100 Pavia, Italy, Toxicology Research Division, Bureau of Chemical Safety Food Directorate, Health Products and Food Branch Health Canada, Ottawa, Ontario K1A0K9, Canada, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA, Centre for Advanced Research, King George's Medical University, Chowk, Lucknow, Uttar Pradesh 226003, India, Mediterranean Institute of Oncology, Viagrande 95029, Italy, Urology Department, kasr Al-Ainy School of Medicine, Cairo University, El Manial, Cairo 12515, Egypt, Department of Experimental and
| | - Gladys N Nangami
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN 37208, USA, Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA, Department of Biology/Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA 30314, USA, Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA, Department of Pathology, Wayne State University, Detroit, MI 48201, USA, Department of Obstetrics and Gynecology, University of Melbourne, Melbourne, Victoria, Australia, Faculty of Pharmacy, Department of Pathology, Kuwait University, Safat 13110, Kuwait, Department of Otolaryngology, University of Michigan Medical College, Ann Arbor, MI 48109, USA, Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY 40506, USA, Department of Environmental and Radiological Health Sciences/Food Science and Human Nutrition, College of Veterinary Medicine and Biomedical Sciences, Colorado State University/Colorado School of Public Health, Fort Collins, CO 80523-1680, USA, Center for Environmental Carcinogenesis and Risk Assessment, Environmental Protection and Health Prevention Agency, Bologna 40126, Italy, Faculty of Medicine and Health Sciences, University Putra, Serdang, Selangor 43400, Malaysia, Istituto di Genetica Molecolare, CNR, via Abbiategrasso 207, 27100 Pavia, Italy, Toxicology Research Division, Bureau of Chemical Safety Food Directorate, Health Products and Food Branch Health Canada, Ottawa, Ontario K1A0K9, Canada, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA, Centre for Advanced Research, King George's Medical University, Chowk, Lucknow, Uttar Pradesh 226003, India, Mediterranean Institute of Oncology, Viagrande 95029, Italy, Urology Department, kasr Al-Ainy School of Medicine, Cairo University, El Manial, Cairo 12515, Egypt, Department of Experimental and
| | - Olugbemiga Ogunkua
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN 37208, USA, Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA, Department of Biology/Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA 30314, USA, Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA, Department of Pathology, Wayne State University, Detroit, MI 48201, USA, Department of Obstetrics and Gynecology, University of Melbourne, Melbourne, Victoria, Australia, Faculty of Pharmacy, Department of Pathology, Kuwait University, Safat 13110, Kuwait, Department of Otolaryngology, University of Michigan Medical College, Ann Arbor, MI 48109, USA, Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY 40506, USA, Department of Environmental and Radiological Health Sciences/Food Science and Human Nutrition, College of Veterinary Medicine and Biomedical Sciences, Colorado State University/Colorado School of Public Health, Fort Collins, CO 80523-1680, USA, Center for Environmental Carcinogenesis and Risk Assessment, Environmental Protection and Health Prevention Agency, Bologna 40126, Italy, Faculty of Medicine and Health Sciences, University Putra, Serdang, Selangor 43400, Malaysia, Istituto di Genetica Molecolare, CNR, via Abbiategrasso 207, 27100 Pavia, Italy, Toxicology Research Division, Bureau of Chemical Safety Food Directorate, Health Products and Food Branch Health Canada, Ottawa, Ontario K1A0K9, Canada, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA, Centre for Advanced Research, King George's Medical University, Chowk, Lucknow, Uttar Pradesh 226003, India, Mediterranean Institute of Oncology, Viagrande 95029, Italy, Urology Department, kasr Al-Ainy School of Medicine, Cairo University, El Manial, Cairo 12515, Egypt, Department of Experimental and
| | - Isabelle R Miousse
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Igor Koturbash
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Valerie Odero-Marah
- Department of Biology/Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA 30314, USA
| | - Lisa J McCawley
- Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA
| | | | - Nuzhat Ahmed
- Department of Obstetrics and Gynecology, University of Melbourne, Melbourne, Victoria, Australia
| | - Yunus Luqmani
- Faculty of Pharmacy, Department of Pathology, Kuwait University, Safat 13110, Kuwait
| | - Zhenbang Chen
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN 37208, USA, Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA, Department of Biology/Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA 30314, USA, Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA, Department of Pathology, Wayne State University, Detroit, MI 48201, USA, Department of Obstetrics and Gynecology, University of Melbourne, Melbourne, Victoria, Australia, Faculty of Pharmacy, Department of Pathology, Kuwait University, Safat 13110, Kuwait, Department of Otolaryngology, University of Michigan Medical College, Ann Arbor, MI 48109, USA, Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY 40506, USA, Department of Environmental and Radiological Health Sciences/Food Science and Human Nutrition, College of Veterinary Medicine and Biomedical Sciences, Colorado State University/Colorado School of Public Health, Fort Collins, CO 80523-1680, USA, Center for Environmental Carcinogenesis and Risk Assessment, Environmental Protection and Health Prevention Agency, Bologna 40126, Italy, Faculty of Medicine and Health Sciences, University Putra, Serdang, Selangor 43400, Malaysia, Istituto di Genetica Molecolare, CNR, via Abbiategrasso 207, 27100 Pavia, Italy, Toxicology Research Division, Bureau of Chemical Safety Food Directorate, Health Products and Food Branch Health Canada, Ottawa, Ontario K1A0K9, Canada, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA, Centre for Advanced Research, King George's Medical University, Chowk, Lucknow, Uttar Pradesh 226003, India, Mediterranean Institute of Oncology, Viagrande 95029, Italy, Urology Department, kasr Al-Ainy School of Medicine, Cairo University, El Manial, Cairo 12515, Egypt, Department of Experimental and
| | - Silvana Papagerakis
- Department of Otolaryngology, University of Michigan Medical College, Ann Arbor, MI 48109, USA
| | - Gregory T Wolf
- Department of Otolaryngology, University of Michigan Medical College, Ann Arbor, MI 48109, USA
| | - Chenfang Dong
- Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY 40506, USA
| | - Binhua P Zhou
- Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY 40506, USA
| | - Dustin G Brown
- Department of Environmental and Radiological Health Sciences/Food Science and Human Nutrition, College of Veterinary Medicine and Biomedical Sciences, Colorado State University/Colorado School of Public Health, Fort Collins, CO 80523-1680, USA
| | - Anna Maria Colacci
- Center for Environmental Carcinogenesis and Risk Assessment, Environmental Protection and Health Prevention Agency, Bologna 40126, Italy
| | - Roslida A Hamid
- Faculty of Medicine and Health Sciences, University Putra, Serdang, Selangor 43400, Malaysia
| | - Chiara Mondello
- Istituto di Genetica Molecolare, CNR, via Abbiategrasso 207, 27100 Pavia, Italy
| | - Jayadev Raju
- Toxicology Research Division, Bureau of Chemical Safety Food Directorate, Health Products and Food Branch Health Canada, Ottawa, Ontario K1A0K9, Canada
| | - Elizabeth P Ryan
- Department of Environmental and Radiological Health Sciences/Food Science and Human Nutrition, College of Veterinary Medicine and Biomedical Sciences, Colorado State University/Colorado School of Public Health, Fort Collins, CO 80523-1680, USA
| | - Jordan Woodrick
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - A Ivana Scovassi
- Istituto di Genetica Molecolare, CNR, via Abbiategrasso 207, 27100 Pavia, Italy
| | - Neetu Singh
- Centre for Advanced Research, King George's Medical University, Chowk, Lucknow, Uttar Pradesh 226003, India
| | - Monica Vaccari
- Center for Environmental Carcinogenesis and Risk Assessment, Environmental Protection and Health Prevention Agency, Bologna 40126, Italy
| | - Rabindra Roy
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Stefano Forte
- Mediterranean Institute of Oncology, Viagrande 95029, Italy
| | - Lorenzo Memeo
- Mediterranean Institute of Oncology, Viagrande 95029, Italy
| | - Hosni K Salem
- Urology Department, kasr Al-Ainy School of Medicine, Cairo University, El Manial, Cairo 12515, Egypt
| | - Amedeo Amedei
- Department of Experimental and Clinical Medicine, University of Firenze, Firenze 50134, Italy and
| | - Rabeah Al-Temaimi
- Faculty of Pharmacy, Department of Pathology, Kuwait University, Safat 13110, Kuwait
| | - Fahd Al-Mulla
- Faculty of Pharmacy, Department of Pathology, Kuwait University, Safat 13110, Kuwait
| | - William H Bisson
- Environmental and Molecular Toxicology, Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331, USA
| | - Sakina E Eltom
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN 37208, USA, Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA, Department of Biology/Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA 30314, USA, Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, USA, Department of Pathology, Wayne State University, Detroit, MI 48201, USA, Department of Obstetrics and Gynecology, University of Melbourne, Melbourne, Victoria, Australia, Faculty of Pharmacy, Department of Pathology, Kuwait University, Safat 13110, Kuwait, Department of Otolaryngology, University of Michigan Medical College, Ann Arbor, MI 48109, USA, Department of Molecular & Cellular Biochemistry, University of Kentucky, Lexington, KY 40506, USA, Department of Environmental and Radiological Health Sciences/Food Science and Human Nutrition, College of Veterinary Medicine and Biomedical Sciences, Colorado State University/Colorado School of Public Health, Fort Collins, CO 80523-1680, USA, Center for Environmental Carcinogenesis and Risk Assessment, Environmental Protection and Health Prevention Agency, Bologna 40126, Italy, Faculty of Medicine and Health Sciences, University Putra, Serdang, Selangor 43400, Malaysia, Istituto di Genetica Molecolare, CNR, via Abbiategrasso 207, 27100 Pavia, Italy, Toxicology Research Division, Bureau of Chemical Safety Food Directorate, Health Products and Food Branch Health Canada, Ottawa, Ontario K1A0K9, Canada, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA, Centre for Advanced Research, King George's Medical University, Chowk, Lucknow, Uttar Pradesh 226003, India, Mediterranean Institute of Oncology, Viagrande 95029, Italy, Urology Department, kasr Al-Ainy School of Medicine, Cairo University, El Manial, Cairo 12515, Egypt, Department of Experimental and
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Contador-Troca M, Alvarez-Barrientos A, Merino JM, Morales-Hernández A, Rodríguez MI, Rey-Barroso J, Barrasa E, Cerezo-Guisado MI, Catalina-Fernández I, Sáenz-Santamaría J, Oliver FJ, Fernandez-Salguero PM. Dioxin receptor regulates aldehyde dehydrogenase to block melanoma tumorigenesis and metastasis. Mol Cancer 2015; 14:148. [PMID: 26242870 PMCID: PMC4524442 DOI: 10.1186/s12943-015-0419-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/22/2015] [Indexed: 01/16/2023] Open
Abstract
Background The dioxin (AhR) receptor can have oncogenic or tumor suppressor activities depending on the phenotype of the target cell. We have shown that AhR knockdown promotes melanoma primary tumorigenesis and lung metastasis in the mouse and that human metastatic melanomas had reduced AhR levels with respect to benign nevi. Methods Mouse melanoma B16F10 cells were engineered by retroviral transduction to stably downregulate AhR expression, Aldh1a1 expression or both. They were characterized for Aldh1a1 activity, stem cell markers and migration and invasion in vitro. Their tumorigenicity in vivo was analyzed using xenografts and lung metastasis assays as well as in vivo imaging. Results Depletion of aldehyde dehydrogenase 1a1 (Aldh1a1) impairs the pro-tumorigenic and pro-metastatic advantage of melanoma cells lacking AhR expression (sh-AhR). Thus, Aldh1a1 knockdown in sh-AhR cells (sh-AhR + sh-Aldh1a1) diminished their migration and invasion potentials and blocked tumor growth and metastasis to the lungs in immunocompetent AhR+/+ recipient mice. However, Aldh1a1 downmodulation in AhR-expressing B16F10 cells did not significantly affect tumor growth in vivo. Aldh1a1 knockdown reduced the high levels of CD133+/CD29+/CD44+ cells, melanosphere size and the expression of the pluripotency marker Sox2 in sh-AhR cells. Interestingly, Sox2 increased Aldh1a1 expression in sh-AhR but not in sh-AhR + sh-Aldh1a1 cells, suggesting that Aldh1a1 and Sox2 may be co-regulated in melanoma cells. In vivo imaging revealed that mice inoculated with AhR + Aldh1a1 knockdown cells had reduced tumor burden and enhanced survival than those receiving Aldh1a1-expressing sh-AhR cells. Conclusions Aldh1a1 overactivation in an AhR-deficient background enhances melanoma progression. Since AhR may antagonize the protumoral effects of Aldh1a1, the AhRlow-Aldh1a1high phenotype could be indicative of bad outcome in melanoma. Electronic supplementary material The online version of this article (doi:10.1186/s12943-015-0419-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- María Contador-Troca
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, 06071, Badajoz, Spain.
| | | | - Jaime M Merino
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, 06071, Badajoz, Spain.
| | | | - María I Rodríguez
- Instituto de Parasitología y Biomedicina López Neyra, CSIC, 18016, Granada, Spain.
| | - Javier Rey-Barroso
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, 06071, Badajoz, Spain.
| | - Eva Barrasa
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, 06071, Badajoz, Spain.
| | - María I Cerezo-Guisado
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, 06071, Badajoz, Spain.
| | | | - Javier Sáenz-Santamaría
- Servicio de Anatomía Patológica, Hospital Universitario Infanta Cristina, 06071, Badajoz, Spain.
| | - Francisco J Oliver
- Instituto de Parasitología y Biomedicina López Neyra, CSIC, 18016, Granada, Spain.
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Mladenova DN, Dahlstrom JE, Tran PN, Benthani F, Bean EG, Ng I, Pangon L, Currey N, Kohonen-Corish MRJ. HIF1α deficiency reduces inflammation in a mouse model of proximal colon cancer. Dis Model Mech 2015; 8:1093-103. [PMID: 26183215 PMCID: PMC4582097 DOI: 10.1242/dmm.019000] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 07/07/2015] [Indexed: 01/21/2023] Open
Abstract
Hypoxia-inducible factor 1α (HIF1α) is a transcription factor that regulates the adaptation of cells to hypoxic microenvironments, for example inside solid tumours. Stabilisation of HIF1α can also occur in normoxic conditions in inflamed tissue or as a result of inactivating mutations in negative regulators of HIF1α. Aberrant overexpression of HIF1α in many different cancers has led to intensive efforts to develop HIF1α-targeted therapies. However, the role of HIF1α is still poorly understood in chronic inflammation that predisposes the colon to carcinogenesis. We have previously reported that the transcription of HIF1α is upregulated and that the protein is stabilised in inflammatory lesions that are caused by the non-steroidal anti-inflammatory drug (NSAID) sulindac in the mouse proximal colon. Here, we exploited this side effect of long-term sulindac administration to analyse the role of HIF1α in colon inflammation using mice with a Villin-Cre-induced deletion of Hif1α exon 2 in the intestinal epithelium (Hif1αΔIEC). We also analysed the effect of sulindac sulfide on the aryl hydrocarbon receptor (AHR) pathway in vitro in colon cancer cells. Most sulindac-treated mice developed visible lesions, resembling the appearance of flat adenomas in the human colon, surrounded by macroscopically normal mucosa. Hif1αΔIEC mice still developed lesions but they were smaller than in the Hif1α-floxed siblings (Hif1αF/F). Microscopically, Hif1αΔIEC mice had significantly less severe colon inflammation than Hif1αF/F mice. Molecular analysis showed reduced MIF expression and increased E-cadherin mRNA expression in the colon of sulindac-treated Hif1αΔIEC mice. However, immunohistochemistry analysis revealed a defect of E-cadherin protein expression in sulindac-treated Hif1αΔIEC mice. Sulindac sulfide treatment in vitro upregulated Hif1α, c-JUN and IL8 expression through the AHR pathway. Taken together, HIF1α expression augments inflammation in the proximal colon of sulindac-treated mice, and AHR activation by sulindac might lead to the reduction of E-cadherin protein levels through the mitogen-activated protein kinase (MAPK) pathway. Summary: HIF1α deficiency reduces inflammation in the mouse proximal colon but is associated with defective E-cadherin expression in colon epithelial cells when mice lacking intestinal epithelium expression of Hif1α are challenged with sulindac.
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Affiliation(s)
- Dessislava N Mladenova
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Jane E Dahlstrom
- ACT Pathology, The Canberra Hospital and Australian National University Medical School, Canberra, Australian Capital Territory, 2605, Australia
| | - Phuong N Tran
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Fahad Benthani
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Elaine G Bean
- ACT Pathology, The Canberra Hospital and Australian National University Medical School, Canberra, Australian Capital Territory, 2605, Australia
| | - Irvin Ng
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Laurent Pangon
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Nicola Currey
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Maija R J Kohonen-Corish
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia St Vincent's Clinical School, UNSW Medicine, UNSW Australia, Sydney, New South Wales, 2052, Australia School of Medicine, University of Western Sydney, Sydney, New South Wales, 2560, Australia
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Oh J, Kwak JH, Kwon DY, Kim AY, Oh DS, Je NK, Lee J, Jung YS. Transformation of Mouse Liver Cells by Methylcholanthrene Leads to Phenotypic Changes Associated with Epithelial-mesenchymal Transition. Toxicol Res 2015; 30:261-6. [PMID: 25584145 PMCID: PMC4289926 DOI: 10.5487/tr.2014.30.4.261] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 12/21/2014] [Accepted: 12/22/2014] [Indexed: 02/05/2023] Open
Abstract
Environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs) have been implicated in cancer development and progression. However, the effects of PAHs on carcinogenesis are still poorly understood. Here, we characterized a mouse cancer cell line BNL 1ME A. 7R.1 (1MEA) derived by transformation of non-tumorigenic liver cell line BNL CL.2 (BNL) using 3-methylcholanthrene (3MC), a carcinogenic PAH. RT-PCR and immunoblot analysis were used to determine the expression level of mRNA and proteins, respectively. To determine functionality, cell motility was assessed in vitro using a transwell migration assay. Both mRNA and protein levels of E-cadherin were significantly decreased in 1MEA cells in comparison with BNL cells. While the expression levels of mesenchymal markers and related transcription factors were enhanced in 1MEA cells, which could lead to increase in cell motility. Indeed, we found that 7-day exposure of BNL cells to 3-MC reduced the level of the adhesion molecule and epithelial marker Ecadherin and increased reciprocally the level of the mesenchymal marker vimentin in a dose-dependent manner. Taken together, these results indicate that the process of epithelial-mesenchymal transition (EMT) may be activated during premalignant transformation induced by 3-MC. A mechanism study to elucidate the relation between 3-MC exposure and EMT is underway in our laboratory.
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Affiliation(s)
- Jiyun Oh
- College of Pharmacy, Pusan National University, Busan, Korea
| | - Jae-Hwan Kwak
- College of Pharmacy, Kyungsung University, Busan, Korea
| | - Do-Young Kwon
- Risk Assessment Division, National Institute of Environmental Research, Incheon, Korea
| | - A-Young Kim
- College of Pharmacy, Pusan National University, Busan, Korea
| | - Dal-Seok Oh
- Korea Institute of Oriental Medicine, Daejeon, Korea
| | - Nam Kyung Je
- College of Pharmacy, Pusan National University, Busan, Korea
| | - Jaewon Lee
- College of Pharmacy, Pusan National University, Busan, Korea
| | - Young-Suk Jung
- College of Pharmacy, Pusan National University, Busan, Korea
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Potential involvement of chemicals in liver cancer progression: An alternative toxicological approach combining biomarkers and innovative technologies. Toxicol In Vitro 2014; 28:1507-20. [DOI: 10.1016/j.tiv.2014.06.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 06/18/2014] [Accepted: 06/23/2014] [Indexed: 12/12/2022]
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Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that is best known for mediating the toxicity and tumour-promoting properties of the carcinogen 2,3,7,8-tetrachlorodibenzo-p-dioxin, commonly referred to as ‘dioxin’. AHR influences the major stages of tumorigenesis — initiation, promotion, progression and metastasis — and physiologically relevant AHR ligands are often formed during disease states or during heightened innate and adaptive immune responses. Interestingly, ligand specificity and affinity vary between rodents and humans. Studies of aggressive tumours and tumour cell lines show increased levels of AHR and constitutive localization of this receptor in the nucleus. This suggests that the AHR is chronically activated in tumours, thus facilitating tumour progression. This Review discusses the role of AHR in tumorigenesis and the potential for therapeutic modulation of its activity in tumours.
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Kalkhof S, Dautel F, Loguercio S, Baumann S, Trump S, Jungnickel H, Otto W, Rudzok S, Potratz S, Luch A, Lehmann I, Beyer A, von Bergen M. Pathway and time-resolved benzo[a]pyrene toxicity on Hepa1c1c7 cells at toxic and subtoxic exposure. J Proteome Res 2014; 14:164-82. [PMID: 25362887 DOI: 10.1021/pr500957t] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Benzo[a]pyrene (B[a]P) is an environmental contaminant mainly studied for its toxic/carcinogenic effects. For a comprehensive and pathway orientated mechanistic understanding of the effects directly triggered by a toxic (5 μM) or a subtoxic (50 nM) concentration of B[a]P or indirectly by its metabolites, we conducted time series experiments for up to 24 h to study the effects in murine hepatocytes. These cells rapidly take up and actively metabolize B[a]P, which was followed by quantitative analysis of the concentration of intracellular B[a]P and seven representative degradation products. Exposure with 5 μM B[a]P led to a maximal intracellular concentration of 1604 pmol/5 × 10(4) cells, leveling at 55 pmol/5 × 10(4) cells by the end of the time course. Changes in the global proteome (>1000 protein profiles) and metabolome (163 metabolites) were assessed in combination with B[a]P degradation. Abundance profiles of 236 (both concentrations), 190 (only 5 μM), and 150 (only 50 nM) proteins were found to be regulated in response to B[a]P in a time-dependent manner. At the endogenous metabolite level amino acids, acylcarnitines and glycerophospholipids were particularly affected by B[a]P. The comprehensive chemical, proteome and metabolomic data enabled the identification of effects on the pathway level in a time-resolved manner. So in addition to known alterations, also protein synthesis, lipid metabolism, and membrane dysfunction were identified as B[a]P specific effects.
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Affiliation(s)
- Stefan Kalkhof
- Department of Proteomics, UFZ, Helmholtz-Centre for Environmental Research , Permoserstr. 15, 04318 Leipzig, Germany
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Rey-Barroso J, Alvarez-Barrientos A, Rico-Leo E, Contador-Troca M, Carvajal-Gonzalez JM, Echarri A, Del Pozo MA, Fernandez-Salguero PM. The Dioxin receptor modulates Caveolin-1 mobilization during directional migration: role of cholesterol. Cell Commun Signal 2014; 12:57. [PMID: 25238970 PMCID: PMC4172968 DOI: 10.1186/s12964-014-0057-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Accepted: 09/05/2014] [Indexed: 01/16/2023] Open
Abstract
Background Adhesion and migration are relevant physiological functions that must be regulated by the cell under both normal and pathological conditions. The dioxin receptor (AhR) has emerged as a transcription factor regulating both processes in mesenchymal, epithelial and endothelial cells. Indirect results suggest that AhR could cooperate not only with additional transcription factors but also with membrane-associated proteins to drive such processes. Results In this study, we have used immortalized and primary dermal fibroblasts from wild type (AhR+/+) and AhR-null (AhR−/−) mice to show that AhR modulates membrane distribution and mobilization of caveolin-1 (Cav-1) during directional cell migration. AhR co-immunoprecipitated with Cav-1 and a fraction of both proteins co-localized to detergent-resistant membrane microdomains (DRM). Consistent with a role of AhR in the process, AhR−/− cells had a significant reduction in Cav-1 in DRMs. Moreover, high cell density reduced AhR nuclear levels and moved Cav-1 from DRMs to the soluble membrane in AhR+/+ but not in AhR−/− cells. Tyrosine-14 phosphorylation had a complex role in the mechanism since its upregulation reduced Cav-1 in DRMs in both AhR+/+ and AhR−/−cells, despite the lower basal levels of Y14-Cav-1 in the null cells. Fluorescence recovery after photobleaching revealed that AhR knock-down blocked Cav-1 transport to the plasma membrane, a deficit possibly influencing its depleted levels in DRMs. Membrane distribution of Cav-1 in AhR-null fibroblasts correlated with higher levels of cholesterol and with disrupted membrane microdomains, whereas addition of exogenous cholesterol changed the Cav-1 distribution of AhR+/+ cells to the null phenotype. Consistently, higher cholesterol levels enhanced caveolae-dependent endocytosis in AhR-null cells. Conclusions These results suggest that AhR modulates Cav-1 distribution in migrating cells through the control of cholesterol-enriched membrane microdomains. Our study also supports the likely possibility of membrane-related, transcription factor independent, functions of AhR. Electronic supplementary material The online version of this article (doi:10.1186/s12964-014-0057-7) contains supplementary material, which is available to authorized users.
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Tsai CF, Hsieh TH, Lee JN, Hsu CY, Wang YC, Lai FJ, Kuo KK, Wu HL, Tsai EM, Kuo PL. Benzyl butyl phthalate induces migration, invasion, and angiogenesis of Huh7 hepatocellular carcinoma cells through nongenomic AhR/G-protein signaling. BMC Cancer 2014; 14:556. [PMID: 25081364 PMCID: PMC4131049 DOI: 10.1186/1471-2407-14-556] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 07/18/2014] [Indexed: 01/04/2023] Open
Abstract
Background The widespread use of phthalates as plasticizers has raised public health concerns regarding their adverse effects, including an association with cancer. Although animal investigations have suggested an association between phthalate exposure and hepatocellular carcinoma, the mechanisms are unknown. Methods The hepatocellular carcinoma cell line Huh7 was treated with benzyl butyl phthalate (BBP), and then analyzed by total internal reflection fluorescence microscopy, confocal microscopy and double immunogold transmission electron microscopy. Following BBP treatment, mRNA levels were measured by RT-PCR, protein levels were measured using western blot, and vascular endothelial growth factor levels were measured by an enzyme-linked immunosorbent assay. Cell migration and invasion assays were evaluated by transwell, and angiogenesis were performed by a tube formation assay. Nude mice were used to investigate metastasis and angiogenesis in vivo. Results BBP affected hepatocellular carcinoma progression through the aryl hydrocarbon receptor (AhR) and that benzyl butyl phthalate (BBP) stimulated AhR at the cell surface, which then interacted with G proteins and triggered a downstream signaling cascade. BBP activated AhR through a nongenomic action involving G-protein signaling rather than the classical genomic AhR action. BBP treatment promoted cell migration and invasion in vitro and metastasis in vivo via the AhR/Gβ/PI3K/Akt/NF-κB pathway. In addition, BBP induced both in vitro and in vivo angiogenesis through the AhR/ERK/VEGF pathway. Conclusions These findings suggest a novel nongenomic AhR mechanism involving G-protein signaling induced by phthalates, which contributes to tumor progression of hepatocellular carcinoma. Electronic supplementary material The online version of this article (doi:10.1186/1471-2407-14-556) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Eing-Mei Tsai
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City 807, Taiwan.
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Zhu C, Xie Q, Zhao B. The role of AhR in autoimmune regulation and its potential as a therapeutic target against CD4 T cell mediated inflammatory disorder. Int J Mol Sci 2014; 15:10116-35. [PMID: 24905409 PMCID: PMC4100143 DOI: 10.3390/ijms150610116] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 03/26/2014] [Accepted: 03/27/2014] [Indexed: 02/07/2023] Open
Abstract
AhR has recently emerged as a critical physiological regulator of immune responses affecting both innate and adaptive systems. Since the AhR signaling pathway represents an important link between environmental stimulators and immune-mediated inflammatory disorder, it has become the object of great interest among researchers recently. The current review discusses new insights into the mechanisms of action of a select group of inflammatory autoimmune diseases and the ligand-activated AhR signaling pathway. Representative ligands of AhR, both exogenous and endogenous, are also reviewed relative to their potential use as tools for understanding the role of AhR and as potential therapeutics for the treatment of various inflammatory autoimmune diseases, with a focus on CD4 helper T cells, which play important roles both in self-immune tolerance and in inflammatory autoimmune diseases. Evidence indicating the potential use of these ligands in regulating inflammation in various diseases is highlighted, and potential mechanisms of action causing immune system effects mediated by AhR signaling are also discussed. The current review will contribute to a better understanding of the role of AhR and its signaling pathway in CD4 helper T cell mediated inflammatory disorder. Considering the established importance of AhR in immune regulation and its potential as a therapeutic target, we also think that both further investigation into the molecular mechanisms of immune regulation that are mediated by the ligand-specific AhR signaling pathway, and integrated research and development of new therapeutic drug candidates targeting the AhR signaling pathway should be pursued urgently.
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Affiliation(s)
- Conghui Zhu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Qunhui Xie
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Bin Zhao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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61
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Sallée M, Dou L, Cerini C, Poitevin S, Brunet P, Burtey S. The aryl hydrocarbon receptor-activating effect of uremic toxins from tryptophan metabolism: a new concept to understand cardiovascular complications of chronic kidney disease. Toxins (Basel) 2014; 6:934-49. [PMID: 24599232 PMCID: PMC3968369 DOI: 10.3390/toxins6030934] [Citation(s) in RCA: 167] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 02/19/2014] [Accepted: 02/24/2014] [Indexed: 12/13/2022] Open
Abstract
Patients with chronic kidney disease (CKD) have a higher risk of cardiovascular diseases and suffer from accelerated atherosclerosis. CKD patients are permanently exposed to uremic toxins, making them good candidates as pathogenic agents. We focus here on uremic toxins from tryptophan metabolism because of their potential involvement in cardiovascular toxicity: indolic uremic toxins (indoxyl sulfate, indole-3 acetic acid, and indoxyl-β-d-glucuronide) and uremic toxins from the kynurenine pathway (kynurenine, kynurenic acid, anthranilic acid, 3-hydroxykynurenine, 3-hydroxyanthranilic acid, and quinolinic acid). Uremic toxins derived from tryptophan are endogenous ligands of the transcription factor aryl hydrocarbon receptor (AhR). AhR, also known as the dioxin receptor, interacts with various regulatory and signaling proteins, including protein kinases and phosphatases, and Nuclear Factor-Kappa-B. AhR activation by 2,3,7,8-tetrachlorodibenzo-p-dioxin and some polychlorinated biphenyls is associated with an increase in cardiovascular disease in humans and in mice. In addition, this AhR activation mediates cardiotoxicity, vascular inflammation, and a procoagulant and prooxidant phenotype of vascular cells. Uremic toxins derived from tryptophan have prooxidant, proinflammatory, procoagulant, and pro-apoptotic effects on cells involved in the cardiovascular system, and some of them are related with cardiovascular complications in CKD. We discuss here how the cardiovascular effects of these uremic toxins could be mediated by AhR activation, in a “dioxin-like” effect.
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Affiliation(s)
- Marion Sallée
- Aix Marseille Université, Inserm, VRCM, UMR_S 1076, Marseille13005, France.
| | - Laetitia Dou
- Aix Marseille Université, Inserm, VRCM, UMR_S 1076, Marseille13005, France.
| | - Claire Cerini
- Aix Marseille Université, Inserm, VRCM, UMR_S 1076, Marseille13005, France.
| | - Stéphane Poitevin
- Aix Marseille Université, Inserm, VRCM, UMR_S 1076, Marseille13005, France.
| | - Philippe Brunet
- Aix Marseille Université, Inserm, VRCM, UMR_S 1076, Marseille13005, France.
| | - Stéphane Burtey
- Aix Marseille Université, Inserm, VRCM, UMR_S 1076, Marseille13005, France.
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Powell JB, Ghotbaddini M. Cancer-promoting and Inhibiting Effects of Dietary Compounds: Role of the Aryl Hydrocarbon Receptor (AhR). ACTA ACUST UNITED AC 2014; 3. [PMID: 25258701 PMCID: PMC4172379 DOI: 10.4172/2167-0501.1000131] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Polyaromatic hydrocarbons, heterocyclic aromatic amines and dioxin-like compounds are environmental carcinogens shown to initiate cancer in a number of tissue types including prostate and breast. These environmental carcinogens elicit their effects through interacting with the aryl hydrocarbon receptor (AhR), a ligand activated transcription factor. Naturally occurring compounds found in fruits and vegetables shown to have anti-carcinogenic effects also interact with the AhR. This review explores dietary and environmental exposure to chemical carcinogens and beneficial natural compounds whose effects are elicited by the AhR.
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Affiliation(s)
- Joann B Powell
- Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA USA
| | - Maryam Ghotbaddini
- Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, GA USA
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63
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Pierre S, Chevallier A, Teixeira-Clerc F, Ambolet-Camoit A, Bui LC, Bats AS, Fournet JC, Fernandez-Salguero P, Aggerbeck M, Lotersztajn S, Barouki R, Coumoul X. Aryl hydrocarbon receptor-dependent induction of liver fibrosis by dioxin. Toxicol Sci 2013; 137:114-24. [PMID: 24154488 DOI: 10.1093/toxsci/kft236] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The contribution of environmental pollutants to liver fibrosis is an important and poorly explored issue. In vitro studies suggest that the environmental pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other aryl hydrocarbon receptor (AhR) ligands induce several genes that are known to be upregulated during liver fibrosis. Our aim was to determine whether exposure to such pollutants can lead to liver fibrosis and to characterize the mechanisms of action. Mice were treated for 2, 14, or 42 days, once a week with 25 µg/kg of TCDD. Gene and protein expression, in vitro and in vivo, as well as liver histology were investigated for each treatment. Treatment of mice with TCDD for 2 weeks modified the hepatic expression of markers of fibrosis such as collagen 1A1 and α-smooth muscle actin. This is not observed in AhR knockout mice. Following 6 weeks of treatment, histological features of murine hepatic fibrosis became apparent. In parallel, the levels of inflammatory cytokines (interleukin-1 beta, tumor necrosis factor α) and of markers of activated fibroblasts(fibroblast-specific protein 1) were found to be upregulated. Interestingly, we also found increased expression of genes of the TGF-β pathway and a concomitant decrease of miR-200a levels. Because the transcription factors of the Snail family were shown to be involved in liver fibrosis, we studied their regulation by TCDD. Two members of the Snail family were increased, whereas their negative targets, the epithelial marker E-cadherin and Claudin 1, were decreased. Further, the expression of mesenchymal markers was increased. Finally, we confirmed that Snai2 is a direct transcriptional target of TCDD in the human hepatocarcinoma cell line, HepG2. The AhR ligand, TCDD, induces hepatic fibrosis by directly regulating profibrotic pathways.
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Affiliation(s)
- Stéphane Pierre
- * INSERM UMR-S 747, Toxicologie Pharmacologie et Signalisation Cellulaire, Paris, France
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Safe S, Lee SO, Jin UH. Role of the aryl hydrocarbon receptor in carcinogenesis and potential as a drug target. Toxicol Sci 2013; 135:1-16. [PMID: 23771949 PMCID: PMC3748760 DOI: 10.1093/toxsci/kft128] [Citation(s) in RCA: 205] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 06/03/2013] [Indexed: 12/22/2022] Open
Abstract
The aryl hydrocarbon receptor (AHR) is highly expressed in multiple organs and tissues, and there is increasing evidence that the AHR plays an important role in cellular homeostasis and disease. The AHR is expressed in multiple tumor types, in cancer cell lines, and in tumors from animal models, and the function of the AHR has been determined by RNA interference, overexpression, and inhibition studies. With few exceptions, knockdown of the AHR resulted in decreased proliferation and/or invasion and migration of cancer cell lines, and in vivo studies in mice overexpressing the constitutively active AHR exhibited enhanced stomach and liver cancers, suggesting a pro-oncogenic role for the AHR. In contrast, loss of the AHR in transgenic mice that spontaneously develop colonic tumors and in carcinogen-induced liver tumors resulted in increased carcinogenesis, suggesting that the receptor may exhibit antitumorigenic activity prior to tumor formation. AHR ligands also either enhanced or inhibited tumorigenesis, and these effects were highly tumor specific, demonstrating that selective AHR modulators that exhibit agonist or antagonist activities represent an important new class of anticancer agents that can be directed against multiple tumors.
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Affiliation(s)
- Stephen Safe
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas 77843-4466, USA.
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Gerbal-Chaloin S, Iankova I, Maurel P, Daujat-Chavanieu M. Nuclear receptors in the cross-talk of drug metabolism and inflammation. Drug Metab Rev 2013; 45:122-44. [PMID: 23330545 DOI: 10.3109/03602532.2012.756011] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Inflammation and infection have long been known to affect the activity and expression of enzymes involved in hepatic and extrahepatic drug clearance. Significant advances have been made to elucidate the molecular mechanisms underlying the complex cross-talk between inflammation and drug-metabolism alterations. The emergent role of ligand-activated transcriptional regulators, belonging to the nuclear receptor (NR) superfamily, is now well established. The NRs, pregnane X receptor, constitutive androstane receptor, retinoic X receptor, glucocorticoid receptor, and hepatocyte nuclear factor 4, and the basic helix-loop-helix/Per-ARNT-Sim family member, aryl hydrocarbon receptor, are the main regulators of the detoxification function. According to the panel of mediators secreted during inflammation, a cascade of numerous signaling pathways is activated, including nuclear factor kappa B, mitogen-activated protein kinase, and the Janus kinase/signal transducer and activator of transcription pathways. Complex cross-talk is established between these signaling pathways regulating either constitutive or induced gene expression. In most cases, a mutual antagonism between xenosensor and inflammation signaling occurs. This review focuses on the molecular and cellular mechanisms implicated in this cross-talk.
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Goode GD, Ballard BR, Manning HC, Freeman ML, Kang Y, Eltom SE. Knockdown of aberrantly upregulated aryl hydrocarbon receptor reduces tumor growth and metastasis of MDA-MB-231 human breast cancer cell line. Int J Cancer 2013; 133:2769-80. [PMID: 23733406 DOI: 10.1002/ijc.28297] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 05/10/2013] [Indexed: 11/10/2022]
Abstract
The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor that belongs to the basic-helix-loop-helix (bHLH)-Per-ARNT-Sim (PAS) superfamily of transcription factors, mediates toxic response induced by environmental chemicals such as polycyclic aromatic hydrocarbons (PAH). AhR is expressed at high levels in several human breast carcinoma cell lines in direct correlation with the degree of their malignancy. Recent studies suggest a possible role for AhR in cancer independent of PAH. Therefore, we established stable AhR knockdown cells of the human breast cancer cell line MDA-MB-231 and analyzed their tumorigenic properties in in vitro and in vivo model systems. In addition we analyzed their response to radiation and chemotherapeutic treatment. AhR knockdown attenuated these cells tumorigenic properties in vitro including proliferation, anchorage independent growth, migration and apoptosis and reduced orthotopic xenograft tumor growth and lung metastasis in vivo. Notably, we observed that AhR knockdown enhanced radiation-induced apoptosis as well as significantly decreased cell clonogenic survival. Furthermore, AhR knockdown in MDA-MB-231 cells sensitized them to paclitaxel treatment, evident by a decrease in the required cytotoxic dose. Subsequent analysis revealed AhR knockdown significantly reduced phosphorylation of AKT, which impacts cell proliferation and survival. Apoptosis-focused gene expression analyses revealed an altered expression of genes regulating apoptosis in MDA-MB-231 cells. Collectively, our data identify AhR as a potential novel therapeutic target in the treatment of metastatic breast cancer.
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Affiliation(s)
- Gennifer D Goode
- Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN
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67
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Bock KW. The human Ah receptor: hints from dioxin toxicities to deregulated target genes and physiological functions. Biol Chem 2013; 394:729-39. [DOI: 10.1515/hsz-2012-0340] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 01/25/2013] [Indexed: 01/22/2023]
Abstract
Abstract
Marked species differences of dioxin toxicity prompted the review of three well-studied human dioxin toxicities (chloracne, inflammation and cancer) and deregulated Ah receptor (AhR) target genes to obtain hints as to the physiological functions of this receptor. Dioxin here stands for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Microarray analysis of dermal cysts from a dioxin-poisoned patient revealed, in addition to induced CYP1A1, increased expression of gremlin, an antagonist of bone morphogenetic proteins. Dioxin-mediated skin and intestinal inflammation is associated with deregulated T cell differentiation. In the supernatant of CD4+ T cells obtained from the dioxin-poisoned patient, increased interleukin-22 was detected, a cytokine that may be controlled in part by AhR-regulated Notch. Cancer is one of the long-term consequences of chronic inflammation. In line with dioxin-sensitive lymphoid tissue, enhanced death of lymphoid cancer was observed in the dioxin-exposed Seveso population 25 years after poisoning. Accumulating evidence suggests that endogenous AhR ligands, notably the tryptophan photoproduct 6-formylindolo[3,2-b]carbazole, in contrast to TCDD, is rapidly metabolized by AhR-induced CYP1A1. The feedback loop between 6-formylindolo[3,2-b]carbazole, AhR and CYP1A1 guarantees transient activation that, in contrast to sustained activation by TCDD, may be essential for a putative role of the AhR in stem/progenitor cell homeostasis.
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68
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Procházková J, Kabátková M, Šmerdová L, Pacherník J, Sykorová D, Kohoutek J, Šimečková P, Hrubá E, Kozubík A, Machala M, Vondráček J. Aryl hydrocarbon receptor negatively regulates expression of the plakoglobin gene (jup). Toxicol Sci 2013; 134:258-70. [PMID: 23690540 DOI: 10.1093/toxsci/kft110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Plakoglobin is an important component of intercellular junctions, including both desmosomes and adherens junctions, which is known as a tumor suppressor. Although mutations in the plakoglobin gene (Jup) and/or changes in its protein levels have been observed in various disease states, including cancer progression or cardiovascular defects, the information about endogenous or exogenous stimuli orchestrating Jup expression is limited. Here we show that the aryl hydrocarbon receptor (AhR) may regulate Jup expression in a cell-specific manner. We observed a significant suppressive effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a model toxic exogenous activator of the AhR signaling, on Jup expression in a variety of experimental models derived from rodent tissues, including contact-inhibited rat liver progenitor cells (where TCDD induces cell proliferation), rat and mouse hepatoma cell models (where TCDD inhibits cell cycle progression), cardiac cells derived from the mouse embryonic stem cells, or cardiomyocytes isolated from neonatal rat hearts. The small interfering RNA (siRNA)-mediated knockdown of AhR confirmed its role in both basal and TCDD-deregulated Jup expression. The analysis of genomic DNA located ~2.5kb upstream of rat Jup gene revealed a presence of evolutionarily conserved AhR binding motifs, which were confirmed upon their cloning into luciferase reporter construct. The siRNA-mediated knockdown of Jup expression affected both proliferation and attachment of liver progenitor cells. The present data indicate that the AhR may contribute to negative regulation of Jup gene expression in rodent cellular models, which may affect cell adherence and proliferation.
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Affiliation(s)
- Jiřina Procházková
- Department of Cytokinetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, 61265 Brno, Czech Republic
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Rey-Barroso J, Colo GP, Alvarez-Barrientos A, Redondo-Muñoz J, Carvajal-González JM, Mulero-Navarro S, García-Pardo A, Teixidó J, Fernandez-Salguero PM. The dioxin receptor controls β1 integrin activation in fibroblasts through a Cbp–Csk–Src pathway. Cell Signal 2013; 25:848-59. [DOI: 10.1016/j.cellsig.2013.01.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 01/07/2013] [Accepted: 01/09/2013] [Indexed: 11/30/2022]
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Rico-Leo EM, Alvarez-Barrientos A, Fernandez-Salguero PM. Dioxin receptor expression inhibits basal and transforming growth factor β-induced epithelial-to-mesenchymal transition. J Biol Chem 2013; 288:7841-7856. [PMID: 23382382 DOI: 10.1074/jbc.m112.425009] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Recent studies have emphasized the role of the dioxin receptor (AhR) in maintaining cell morphology, adhesion, and migration. These novel AhR functions depend on the cell phenotype, and although AhR expression maintains mesenchymal fibroblasts migration, it inhibits keratinocytes motility. These observations prompted us to investigate whether AhR modulates the epithelial-to-mesenchymal transition (EMT). For this, we have used primary AhR(+/+) and AhR(-/-) keratinocytes and NMuMG cells engineered to knock down AhR levels (sh-AhR) or to express a constitutively active receptor (CA-AhR). Both AhR(-/-) keratinocytes and sh-AhR NMuMG cells had increased migration, reduced levels of epithelial markers E-cadherin and β-catenin, and increased expression of mesenchymal markers Snail, Slug/Snai2, vimentin, fibronectin, and α-smooth muscle actin. Consistently, AhR(+/+) and CA-AhR NMuMG cells had reduced migration and enhanced expression of epithelial markers. AhR activation by the agonist FICZ (6-formylindolo[3,2-b]carbazole) inhibited NMuMG migration, whereas the antagonist α-naphthoflavone induced migration as did AhR knockdown. Exogenous TGFβ exacerbated the promigratory mesenchymal phenotype in both AhR-expressing and AhR-depleted cells, although the effects on the latter were more pronounced. Rescuing AhR expression in sh-AhR cells reduced Snail and Slug/Snai2 levels and cell migration and restored E-cadherin levels. Interference of AhR in human HaCaT cells further supported its role in EMT. Interestingly, co-immunoprecipitation and immunofluorescence assays showed that AhR associates in common protein complexes with E-cadherin and β-catenin, suggesting the implication of AhR in cell-cell adhesion. Thus, basal or TGFβ-induced AhR down-modulation could be relevant in the acquisition of a motile EMT phenotype in both normal and transformed epithelial cells.
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Affiliation(s)
- Eva M Rico-Leo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain
| | | | - Pedro M Fernandez-Salguero
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain.
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Xu CX, Wang C, Krager SL, Bottum KM, Tischkau SA. Aryl hydrocarbon receptor activation attenuates Per1 gene induction and influences circadian clock resetting. Toxicol Sci 2013; 132:368-78. [PMID: 23291558 DOI: 10.1093/toxsci/kfs345] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Light-stimulated adjustment of the circadian clock is an important adaptive physiological response that allows maintenance of behavioral synchrony with solar time. Our previous studies indicate that the aryl hydrocarbon receptor (AhR) agonist 2,3,7,8- tetrachlorodibenzo-p-dioxin attenuates light-induced phase resetting in early night. However, the mechanism of inhibition remains unclear. In this study, we showed that another potent AhR agonist-β-naphthoflavone (BNF)-significantly decreased light-induced phase shifts in wild-type (WT) mice, whereas AhR knockout mice had an enhanced response to light that was unaffected by BNF. Mechanistically, BNF blocked light induction of the Per1 transcript in suprachiasmatic nucleus and liver in WT mice, and BNF blocked forskolin (FSK)-induced Per1 transcripts in Hepa-1c1c7 (c7) cells. An E-box decoy did not affect BNF inhibition of FSK-induced Per1 transcripts in c7 cells. cAMP-response element (CRE)-dependent induction of Per1 promoter activity in response to FSK in combination with phorbol 12-tetradecanoate 13-acetate was suppressed in cells that expressed high levels of AhR (c7) compared with cells lacking functional AhR activity (c12). In addition, the inhibitory effect of BNF on FSK-induced Per1 was dependent on phosphorylation of JNK. Together, these results suggest that AhR activation inhibits light-induced phase resetting through the activation of JNK, negative regulation of CREs in the Per1 promoter, and suppression of Per1.
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Affiliation(s)
- Can-Xin Xu
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois 62702, USA
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Brokken LJS, Lundberg-Giwercman Y, Meyts ERD, Eberhard J, Ståhl O, Cohn-Cedermark G, Daugaard G, Arver S, Giwercman A. Association between polymorphisms in the aryl hydrocarbon receptor repressor gene and disseminated testicular germ cell cancer. Front Endocrinol (Lausanne) 2013; 4:4. [PMID: 23420531 PMCID: PMC3572423 DOI: 10.3389/fendo.2013.00004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 01/07/2013] [Indexed: 11/13/2022] Open
Abstract
In the Western world, testicular germ cell cancer (TGCC) is the most common malignancy of young men. The malignant transformation of germ cells is thought to be caused by developmental and hormonal disturbances, probably related to environmental and lifestyle factors because of rapidly increasing incidence of TGCC in some countries. Additionally, there is a strong genetic component that affects susceptibility. However, genetic polymorphisms that have been identified so far only partially explain the risk of TGCC. Many of the persistent environmental pollutants act through the aryl hydrocarbon receptor (AHR). AHR signaling pathway is known to interfere with reproductive hormone signaling, which is supposed to play a role in the pathogenesis and invasive progression of TGCC. The aim of the present study was to identify whether AHR-related polymorphisms were associated with risk as well as histological and clinical features of TGCC in 367 patients and 537 controls. Haplotype-tagging single-nucleotide polymorphisms (SNPs) were genotyped in genes encoding AHR and AHR repressor (AHRR). Binary logistic regression was used to calculate the risk of TGCC, non-seminoma versus seminoma, and metastasis versus localized disease. Four SNPs in AHRR demonstrated a significant allele association with risk to develop metastases (rs2466287: OR = 0.43, 95% CI 0.21-0.90; rs2672725: OR = 0.49, 95% CI: 0.25-0.94; rs6879758: OR = 0.27, 95% CI: 0.08-0.92; rs6896163: OR = 0.34, 95% CI: 0.12-0.98). This finding supports the hypothesis that compounds acting through AHR may play a role in the invasive progression of TGCC, either directly or through modification of reproductive hormone action.
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Affiliation(s)
- Leon J. S. Brokken
- Department of Molecular Reproductive Medicine, Lund University Malmö, Sweden
- *Correspondence: Leon J. S. Brokken, Molecular Reproductive Medicine, Clinical Research Centre, Lund University, House 91, Floor 10, Jan Waldenströms gata 35, 20502 Malmö, Sweden. e-mail:
| | | | | | - Jakob Eberhard
- Department of Oncology, Skåne University HospitalLund, Sweden
| | - Olof Ståhl
- Department of Oncology, Skåne University HospitalLund, Sweden
| | - Gabriella Cohn-Cedermark
- Department of Oncology–Pathology, Radiumhemmet, Karolinska Institute and University HospitalStockholm, Sweden
| | | | - Stefan Arver
- Centre for Andrology and Sexual Medicine, Karolinska University Hospital Huddinge, Department of MedicineStockholm, Sweden
| | - Aleksander Giwercman
- Department of Molecular Reproductive Medicine, Lund University Malmö, Sweden
- Reproductive Medicine Centre, Skåne University HospitalMalmö, Sweden
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73
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Andrysík Z, Procházková J, Kabátková M, Umannová L, Šimečková P, Kohoutek J, Kozubík A, Machala M, Vondráček J. Aryl hydrocarbon receptor-mediated disruption of contact inhibition is associated with connexin43 downregulation and inhibition of gap junctional intercellular communication. Arch Toxicol 2012; 87:491-503. [DOI: 10.1007/s00204-012-0963-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 10/11/2012] [Indexed: 11/29/2022]
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74
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DiNatale BC, Smith K, John K, Krishnegowda G, Amin SG, Perdew GH. Ah receptor antagonism represses head and neck tumor cell aggressive phenotype. Mol Cancer Res 2012; 10:1369-79. [PMID: 22912337 PMCID: PMC3477495 DOI: 10.1158/1541-7786.mcr-12-0216] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The aryl hydrocarbon receptor (AhR) has been shown to play a role in an increasing number of cellular processes. Recent reports have linked the AhR to cell proliferation, cytoskeletal arrangement, and tumor invasiveness in various tumor cell types. The AhR plays a role in the de-repression of the interleukin (IL)6 promoter in certain tumor cell lines, allowing for increased transcriptional activation by cytokines. Here, we show that there is a significant level of constitutive activation of the AhR in cells isolated from patients with head and neck squamous cell carcinoma (HNSCC). Constitutive activation of the AhR in HNSCCs was blocked by antagonist treatment, leading to a reduction in IL6 expression. In addition, the AhR exhibits a high level of expression in HNSCCs than in normal keratinocytes. These findings led to the hypothesis that the basal AhR activity in HNSCCs plays a role in the aggressive phenotype of these tumors and that antagonist treatment could mitigate this phenotype. This study provides evidence that antagonism of the AhR in HNSCC tumor cells, in the absence of exogenous receptor ligands, has a significant effect on tumor cell phenotype. Treatment of these cell lines with the AhR antagonists 6, 2', 4'-trimethoxyflavone, or the more potent GNF351, decreased migration and invasion of HNSCC cells and prevented benzo[a]pyrene-mediated induction of the chemotherapy efflux protein ABCG2. Thus, an AhR antagonist treatment has been shown to have therapeutic potential in HNSCCs through a reduction in aggressive cell phenotype.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily G, Member 2
- ATP-Binding Cassette Transporters/metabolism
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/metabolism
- Carcinoma, Squamous Cell/pathology
- Cell Line, Tumor
- Cell Movement/drug effects
- Cell Nucleus/drug effects
- Cell Nucleus/metabolism
- Cell Proliferation/drug effects
- Cell Survival/drug effects
- Gene Expression Regulation, Neoplastic/drug effects
- Head and Neck Neoplasms/genetics
- Head and Neck Neoplasms/metabolism
- Head and Neck Neoplasms/pathology
- Humans
- Indoles
- Interleukin-6/genetics
- Interleukin-6/metabolism
- Neoplasm Invasiveness
- Neoplasm Proteins/metabolism
- Phenotype
- Purines
- Receptors, Aryl Hydrocarbon/antagonists & inhibitors
- Receptors, Aryl Hydrocarbon/genetics
- Receptors, Aryl Hydrocarbon/metabolism
- Squamous Cell Carcinoma of Head and Neck
- Transcription, Genetic/drug effects
- Up-Regulation/drug effects
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Affiliation(s)
- Brett C DiNatale
- Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA
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75
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Zucchini-Pascal N, Peyre L, de Sousa G, Rahmani R. Organochlorine pesticides induce epithelial to mesenchymal transition of human primary cultured hepatocytes. Food Chem Toxicol 2012; 50:3963-70. [PMID: 22902829 DOI: 10.1016/j.fct.2012.08.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 08/03/2012] [Accepted: 08/05/2012] [Indexed: 12/13/2022]
Abstract
Persistent organic pollutants (POPs) are a group of organic or chemicals that adversely affect human health and are persistent in the environment. These highly toxic compounds include industrial chemicals, pesticides such as organochlorines, and unwanted wastes such as dioxins. Although studies have described the general toxicity effects of organochlorine pesticides, the mechanisms underlying its potential carcinogenic effects in the liver are not well understood. In this study, we analyzed the effect of three organochlorine pesticides (dichlorodiphenyltrichloroethane, heptachlore and endosulfan) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the epithelial to mesenchymal transition (EMT) in primary cultured human hepatocytes. We found that these compounds modified the hepatocyte phenotype, inducing cell spread, formation of lamellipodia structures and reorganization of the actin cytoskeleton in stress fibers. These morphological alterations were accompanied by disruption of cell-cell junctions, E-cadherin repression and albumin down-regulation. Interestingly, these characteristic features of dedifferentiating hepatocytes were correlated with the gain of expression of various mesenchymal genes, including vimentin, fibronectin and its receptor ITGA5. These various results show that organochlorines and TCDD accelerate cultured human hepatocyte dedifferentiation and EMT processes. These events could account, at least in part, for the carcionogenic and/or fibrogenic activities of these POPs.
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Affiliation(s)
- Nathalie Zucchini-Pascal
- Laboratoire de Toxicologie Cellulaire et Moléculaire des Xénobiotiques, INRA, UMR 1331 TOXALIM (Research Center in Food Toxicology), 06903 Sophia Antipolis, France.
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76
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The aryl hydrocarbon receptor regulates focal adhesion sites through a non-genomic FAK/Src pathway. Oncogene 2012; 32:1811-20. [PMID: 22665056 DOI: 10.1038/onc.2012.197] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is commonly described as a transcription factor, which regulates xenobiotic-metabolizing enzymes. Recent studies have suggested that the binding of ligands to the AhR also activates the Src kinase. In this manuscript, we show that the AhR, through the activation of Src, activates focal adhesion kinase (FAK) and promotes integrin clustering. These effects contribute to cell migration. Further, we show that the activation of the AhR increases the interaction of FAK with the metastatic marker, HEF1/NEDD9/CAS-L, and the expression of several integrins. Xenobiotic exposure, thus, may contribute to novel cell-migratory programs.
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77
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Lehtinen L, Vainio P, Wikman H, Reemts J, Hilvo M, Issa R, Pollari S, Brandt B, Oresic M, Pantel K, Kallioniemi O, Iljin K. 15-Hydroxyprostaglandin dehydrogenase associates with poor prognosis in breast cancer, induces epithelial-mesenchymal transition, and promotes cell migration in cultured breast cancer cells. J Pathol 2012; 226:674-86. [PMID: 22072156 DOI: 10.1002/path.3956] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Revised: 10/28/2011] [Accepted: 10/31/2011] [Indexed: 11/11/2022]
Abstract
Breast cancer is the most frequent cancer and the leading cause of cancer-related deaths in women worldwide. The prognosis of breast cancer is tightly correlated with the degree of spread beyond the primary tumour. Arachidonic acid (AA) and prostaglandin E(2) (PGE(2)) are known to regulate tumour metastasis enabling epithelial-mesenchymal transition (EMT). However, the detailed role of 15-hydroxyprostaglandin dehydrogenase (HPGD), the key enzyme degrading prostaglandin E(2) , remains unclear in breast cancer. Here, we show that HPGD mRNA is overexpressed in a subset of clinical breast cancers compared to normal breast tissue samples and that high HPGD mRNA expression associates with poor prognosis. Immunohistochemical staining of primary breast cancer and lymph node metastasis tissue samples confirmed high HPGD protein expression in 20% of the samples, as well as associated HPGD expression with aggressive characteristics, such as increased risk of disease relapse and shorter disease-free survival. Results from cultured cells indicated abundant HPGD expression in highly metastatic breast cancer cells, and impairment of HPGD expression using RNA interference led to a significant decrease in transforming growth factor-β signalling, in cellular arachidonic acid levels as well as in cell migration. Furthermore, gene expression microarray analysis followed by quantitative RT-PCR validation showed that HPGD silencing decreased aryl hydrocarbon receptor signalling and induced mesenchymal-epithelial transition. In conclusion, our results indicate that HPGD is highly expressed in metastatic and aggressive breast cancer and promotes EMT and migration in breast cancer cells.
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Affiliation(s)
- Laura Lehtinen
- Medical Biotechnology, VTT Technical Research Centre of Finland and Turku Centre for Biotechnology, University of Turku, Finland
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78
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c-Jun-N-Terminal Kinase Signaling Is Involved in Cyclosporine-Induced Epithelial Phenotypic Changes. J Transplant 2011; 2012:348604. [PMID: 22028950 PMCID: PMC3199056 DOI: 10.1155/2012/348604] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 08/15/2011] [Indexed: 01/01/2023] Open
Abstract
Tubular epithelial cells play a central role in the pathogenesis of chronic nephropathies. Previous toxicogenomic studies have demonstrated that cyclosporine- (CsA-) induced epithelial phenotypic changes (EPCs) are reminiscent of an incomplete epithelial to mesenchymal transition (EMT) in a TGF-β-independent manner. Furthermore, we identified endoplasmic reticulum (ER) stress as a potential mechanism that may participate in the modulation of tubular cell plasticity during CsA exposure. Because c-jun-N-terminal kinase (JNK), which is activated during ER stress, is implicated in kidney fibrogenesis, we undertook the current study to identify the role of JNK signaling in EPCs induced by CsA. In primary cultures of human renal epithelial cells, CsA activates JNK signaling, and the treatment with a JNK inhibitor reduces the occurrence of cell shape changes, E-cadherin downregulation, cell migration, and Snail-1 expression. Our results suggest that CsA activates JNK signaling, which, in turn, may participate in the morphological alterations through the regulation of Snail-1 expression.
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79
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Hrubá E, Vondráček J, Líbalová H, Topinka J, Bryja V, Souček K, Machala M. Gene expression changes in human prostate carcinoma cells exposed to genotoxic and nongenotoxic aryl hydrocarbon receptor ligands. Toxicol Lett 2011; 206:178-88. [DOI: 10.1016/j.toxlet.2011.07.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 07/11/2011] [Accepted: 07/12/2011] [Indexed: 01/28/2023]
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80
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Denison MS, Soshilov AA, He G, DeGroot DE, Zhao B. Exactly the same but different: promiscuity and diversity in the molecular mechanisms of action of the aryl hydrocarbon (dioxin) receptor. Toxicol Sci 2011; 124:1-22. [PMID: 21908767 DOI: 10.1093/toxsci/kfr218] [Citation(s) in RCA: 561] [Impact Index Per Article: 43.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The Ah receptor (AhR) is a ligand-dependent transcription factor that mediates a wide range of biological and toxicological effects that result from exposure to a structurally diverse variety of synthetic and naturally occurring chemicals. Although the overall mechanism of action of the AhR has been extensively studied and involves a classical nuclear receptor mechanism of action (i.e., ligand-dependent nuclear localization, protein heterodimerization, binding of liganded receptor as a protein complex to its specific DNA recognition sequence and activation of gene expression), details of the exact molecular events that result in most AhR-dependent biochemical, physiological, and toxicological effects are generally lacking. Ongoing research efforts continue to describe an ever-expanding list of ligand-, species-, and tissue-specific spectrum of AhR-dependent biological and toxicological effects that seemingly add even more complexity to the mechanism. However, at the same time, these studies are also identifying and characterizing new pathways and molecular mechanisms by which the AhR exerts its actions and plays key modulatory roles in both endogenous developmental and physiological pathways and response to exogenous chemicals. Here we provide an overview of the classical and nonclassical mechanisms that can contribute to the differential sensitivity and diversity in responses observed in humans and other species following ligand-dependent activation of the AhR signal transduction pathway.
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Affiliation(s)
- Michael S Denison
- Department of Environmental Toxicology, University of California, Davis, California 95616, USA.
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81
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Procházková J, Kabátková M, Bryja V, Umannová L, Bernatík O, Kozubík A, Machala M, Vondráček J. The Interplay of the Aryl Hydrocarbon Receptor and β-Catenin Alters Both AhR-Dependent Transcription and Wnt/β-Catenin Signaling in Liver Progenitors. Toxicol Sci 2011; 122:349-60. [DOI: 10.1093/toxsci/kfr129] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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82
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Wang YJ, Chang H, Kuo YC, Wang CK, Siao SH, Chang LW, Lin P. Synergism between 2,3,7,8-tetrachlorodibenzo-p-dioxin and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone on lung tumor incidence in mice. JOURNAL OF HAZARDOUS MATERIALS 2011; 186:869-875. [PMID: 21167638 DOI: 10.1016/j.jhazmat.2010.11.082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 10/26/2010] [Accepted: 11/20/2010] [Indexed: 05/30/2023]
Abstract
Although 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is classified as a human carcinogen, TCDD only induced oxidative DNA damages. In our present study, we combined TCDD with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) to investigate their tumorigenic effects on lung tumor formation in A/J mice. Application of NNK at a tumorigenic dose (2 mg/mouse) induced lung adenoma in both male and female A/J mice. Neither application of NNK at a non-tumorigenic dose (1 mg/mouse) nor repeated application of TCDD alone increased tumor incidence. Following the single injection of NNK at a non-tumorigenic dose (1 mg/mouse), repeated application of TCDD significantly increased the lung tumor incidence in female, but not in male, A/J mice 24 weeks later. Utilizing the real-time RT-PCR array, we found that P16 mRNA was significantly reduced in female lung, but not male lung, of NNK/TCDD co-treated A/J mice. With immunohistochemical staining, we confirmed that nuclear P16 protein was reduced in the lungs of NNK/TCDD co-treated female mice. These data suggest that P16 reduction at least partially contributed to synergistic effects of TCDD in lung tumorigenesis.
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Affiliation(s)
- Ying-Jan Wang
- Department of Environmental and Occupational Health, National Cheng Kung University, Medical College, Tainan, Taiwan
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83
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Román AC, González-Rico FJ, Moltó E, Hernando H, Neto A, Vicente-Garcia C, Ballestar E, Gómez-Skarmeta JL, Vavrova-Anderson J, White RJ, Montoliu L, Fernández-Salguero PM. Dioxin receptor and SLUG transcription factors regulate the insulator activity of B1 SINE retrotransposons via an RNA polymerase switch. Genome Res 2011; 21:422-32. [PMID: 21324874 DOI: 10.1101/gr.111203.110] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Complex genomes utilize insulators and boundary elements to help define spatial and temporal gene expression patterns. We report that a genome-wide B1 SINE (Short Interspersed Nuclear Element) retrotransposon (B1-X35S) has potent intrinsic insulator activity in cultured cells and live animals. This insulation is mediated by binding of the transcription factors dioxin receptor (AHR) and SLUG (SNAI2) to consensus elements present in the SINE. Transcription of B1-X35S is required for insulation. While basal insulator activity is maintained by RNA polymerase (Pol) III transcription, AHR-induced insulation involves release of Pol III and engagement of Pol II transcription on the same strand. B1-X35S insulation is also associated with enrichment of heterochromatin marks H3K9me3 and H3K27me3 downstream of B1-X35S, an effect that varies with cell type. B1-X35S binds parylated CTCF and, consistent with a chromatin barrier activity, its positioning between two adjacent genes correlates with their differential expression in mouse tissues. Hence, B1 SINE retrotransposons represent genome-wide insulators activated by transcription factors that respond to developmental, oncogenic, or toxicological stimuli.
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Affiliation(s)
- Angel Carlos Román
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain
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84
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Lew BJ, Manickam R, Lawrence BP. Activation of the aryl hydrocarbon receptor during pregnancy in the mouse alters mammary development through direct effects on stromal and epithelial tissues. Biol Reprod 2011; 84:1094-102. [PMID: 21270426 DOI: 10.1095/biolreprod.110.087544] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Activation of the aryl hydrocarbon receptor (AHR), an environment-sensing transcription factor, causes profound impairment of mammary gland differentiation during pregnancy. Defects include decreased ductal branching, poorly formed alveolar structures, suppressed expression of milk proteins, and failure to nutritionally support offspring. AHR is activated by numerous environmental toxins, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and plays an as yet poorly understood role in development and reproduction. To better understand how AHR activation affects pregnancy-associated mammary gland differentiation, we used a combination of ex vivo differentiation, mammary epithelial transplantation, and AHR-deficient mice to determine whether AHR modulates mammary development through a direct effect on mammary epithelial cells (MECs) or by altering paracrine or systemic factors that drive pregnancy-associated differentiation. Studies using mutant mice that express an AHR protein lacking the DNA-binding domain show that defects in pregnancy-associated differentiation require AHR:DNA interactions. We then used fluorescence-based cell sorting to compare changes in gene expression in MECs and whole mammary tissue to gain insight into affected signaling pathways. Our data indicate that activation of the AHR during pregnancy directly affects mammary tissue development via both a direct effect on MECs and through changes in cells of the fat pad, and point to gene targets in MECs and stromal tissues as putative AHR targets.
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Affiliation(s)
- Betina J Lew
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, New York, USA
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85
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Correlation of dysfunction of nonmuscle myosin IIA with increased induction of Cyp1a1 in Hepa-1 cells. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1809:176-83. [PMID: 21216307 DOI: 10.1016/j.bbagrm.2011.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2010] [Revised: 12/20/2010] [Accepted: 01/03/2011] [Indexed: 11/20/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is one of the best known ligand-activated transcription factors and it induces Cyp1a1 transcription by binding with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Recent focus has been on the relationship of AhR with signaling pathways that modulate cell shape and migration. In nonmuscle cells, nonmuscle myosin II is one of the key determinants of cell morphology, but it has not been investigated whether its function is related to Cyp1a1 induction. In this study, we observed that (-)-blebbistatin, which is a specific inhibitor of nonmuscle myosin II, increased the level of CYP1A1-mRNA in Hepa-1 cells. Comparison of (-)-blebbistatin with (+)-blebbistatin, which is an inactive enantiomer, indicated that the increase of CYP1A1-mRNA was due to nonmuscle myosin II inhibition. Subsequent knockdown experiments observed that reduction of nonmuscle myosin IIA, which is only an isoform of nonmuscle myosin II expressed in Hepa-1 cells, was related to the enhancement of TCDD-dependent Cyp1a1 induction. Moreover, chromatin immunoprecipitation assay indicated that the increase of Cyp1a1 induction was the result of transcriptional activation due to increased binding of AhR and RNA polymerase II to the enhancer and proximal promoter regions of Cyp1a1, respectively. These findings provide a new insight into the correlation between the function of nonmuscle myosin II and gene induction.
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86
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Pontillo CA, García MA, Peña D, Cocca C, Chiappini F, Alvarez L, Kleiman de Pisarev D, Randi AS. Activation of c-Src/HER1/STAT5b and HER1/ERK1/2 signaling pathways and cell migration by hexachlorobenzene in MDA-MB-231 human breast cancer cell line. Toxicol Sci 2010; 120:284-96. [PMID: 21205633 DOI: 10.1093/toxsci/kfq390] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Hexachlorobenzene (HCB) is a widespread environmental pollutant. It is a dioxin-like compound and a weak ligand of the aryl hydrocarbon receptor (AhR) protein. HCB is a tumor cocarcinogen in rat mammary gland and an inducer of cell proliferation and c-Src kinase activity in MCF-7 breast cancer cells. This study was carried out to investigate HCB action on c-Src and the human epidermal growth factor receptor (HER1) activities and their downstream signaling pathways, Akt, extracellular-signal-regulated kinase (ERK1/2), and signal transducers and activators of transcription (STAT) 5b, as well as on cell migration in a human breast cancer cell line, MDA-MB-231. We also investigated whether the AhR is involved in HCB-induced effects. We have demonstrated that HCB (0.05μM) produces an early increase of Y416-c-Src, Y845-HER1, Y699-STAT5b, and ERK1/2 phosphorylation. Moreover, our results have shown that the pesticide (15 min) activates these pathways in a dose-dependent manner (0.005, 0.05, 0.5, and 5μM). In contrast, HCB does not alter T308-Akt activation. Pretreatment with a specific inhibitor for c-Src (4-amino-5-(4-chlorophenyl)-7-(t-butyl) pyrazolo[3,4-d]pyrimidine [PP2]) prevents Y845-HER1 and Y699-STAT5b phosphorylation. AG1478, a specific HER1 inhibitor, abrogates HCB-induced STAT5b and ERK1/2 activation, whereas 4,7-orthophenanthroline and α-naphthoflavone, two AhR antagonists, prevent HCB-induced STAT5b and ERK1/2 phosphorylation. HCB enhances cell migration evaluated by scratch motility and transwell assays. Pretreatment with PP2, AG1478, and 4,7-orthophenanthroline suppresses HCB-induced cell migration. These results demonstrate that HCB stimulates c-Src/HER1/STAT5b and HER1/ERK1/2 signaling pathways in MDA-MB-231. c-Src, HER1, and AhR are involved in HCB-induced increase in cell migration. The present study makes a significant contribution to the molecular mechanism of action of HCB in mammary carcinogenesis.
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Affiliation(s)
- Carolina A Pontillo
- Laboratorio de Efectos Biológicos de Contaminantes Ambientales, Departamento de Bioquímica Humana, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
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87
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Dautel F, Kalkhof S, Trump S, Michaelson J, Beyer A, Lehmann I, von Bergen M. DIGE-based protein expression analysis of B[a]P-exposed hepatoma cells reveals a complex stress response including alterations in oxidative stress, cell cycle control, and cytoskeleton motility at toxic and subacute concentrations. J Proteome Res 2010; 10:379-93. [PMID: 21171653 DOI: 10.1021/pr100723d] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Although the effects of high concentrations of the carcinogen benzo[a]pyrene (B[a]P) have been studied extensively, little is known about its effects at subacute toxic concentrations, which are typical for environmental pollutants. We exposed murine Hepa1c1c7 cells to a toxic concentration (5 μM) and a subacute concentration (50 nM) of B[a]P over a period of 2-24 h to differentiate between acute and pseudochronic effects and conducted a time-course analysis of B[a]P-influenced protein expression by DIGE. In total, a set of 120 spots were found to be significantly altered due to B[a]P exposure of which 112 were subsequently identified by mass spectrometry. Clustering and principal component analysis were conducted to identify sets of proteins responding in a concerted manner to the exposure. Our results indicate an immediate response to the contaminant at the protein level and demonstrate that B[a]P exposure alters the cellular response by disturbing proteins involved in oxidative stress, cell cycle regulation, apoptosis, and cytoskeleton organization. Furthermore, network analysis of protein-protein interactions revealed a complex network of interacting, B[a]P-regulated proteins mostly belonging to the cytoskeleton organization and several signal transduction pathways.
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Affiliation(s)
- Franziska Dautel
- Department of Proteomics, UFZ, Helmholtz-Centre for Environmental Research, Leipzig, Germany
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88
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Gassmann K, Abel J, Bothe H, Haarmann-Stemmann T, Merk HF, Quasthoff KN, Rockel TD, Schreiber T, Fritsche E. Species-specific differential AhR expression protects human neural progenitor cells against developmental neurotoxicity of PAHs. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:1571-7. [PMID: 20570779 PMCID: PMC2974695 DOI: 10.1289/ehp.0901545] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 05/21/2010] [Accepted: 06/22/2010] [Indexed: 05/07/2023]
Abstract
BACKGROUND Because of their lipophilicity, persistent organic pollutants (POPs) cross the human placenta, possibly affecting central nervous system development. Most POPs are known aryl hydrocarbon receptor (AhR) ligands and activators of AhR signaling. Therefore, AhR activation has been suggested to cause developmental neurotoxicity (DNT). OBJECTIVE We studied the effects of AhR ligands on basic processes of brain development in two comparative in vitro systems to determine whether AhR-activation is the underlying mechanism for reported DNT of POPs in humans. METHODS We employed neurosphere cultures based on human neural progenitor cells (hNPCs) and wild-type and AhR-deficient mouse NPCs (mNPCs) and studied the effects of different AhR agonists [3-methylcholanthrene (3-MC), benzo(a)pyrene [B(a)P], and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)] and an antagonist [3'-methoxy-4'-nitroflavone (MNF)] on neurosphere development. Moreover, we analyzed expression of AhR and genes involved in AhR signaling. RESULTS In contrast to wild-type mNPCs, hNPCs and AhR-deficient mNPCs were insensitive to AhR agonism or antagonism. Although AhR modulation attenuated wild-type mNPC proliferation and migration, hNPCs and AhR-deficient mNPCs remained unaffected. Results also suggest that species-specific differences resulted from nonfunctional AhR signaling in hNPCs. CONCLUSION Our findings suggest that in contrast to wild-type mNPCs, hNPCs were protected against polycyclic aromatic hydrocarbon-induced DNT because of an absence of AhR This difference may contribute to species-specific differences in sensitivity to POPs.
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Affiliation(s)
- Kathrin Gassmann
- Department of Molecular Toxicology, Institut für umweltmedizinische Forschung gGmbH, Heinrich Heine University, Düsseldorf, Germany
| | - Josef Abel
- Department of Molecular Toxicology, Institut für umweltmedizinische Forschung gGmbH, Heinrich Heine University, Düsseldorf, Germany
| | - Hanno Bothe
- Department of Molecular Toxicology, Institut für umweltmedizinische Forschung gGmbH, Heinrich Heine University, Düsseldorf, Germany
| | - Thomas Haarmann-Stemmann
- Department of Molecular Toxicology, Institut für umweltmedizinische Forschung gGmbH, Heinrich Heine University, Düsseldorf, Germany
| | - Hans F. Merk
- Department of Dermatology, University Hospital, RWTH Aachen, Aachen, Germany
| | - Kim N. Quasthoff
- Department of Molecular Toxicology, Institut für umweltmedizinische Forschung gGmbH, Heinrich Heine University, Düsseldorf, Germany
| | - Thomas Dino Rockel
- Department of Molecular Toxicology, Institut für umweltmedizinische Forschung gGmbH, Heinrich Heine University, Düsseldorf, Germany
| | - Timm Schreiber
- Department of Molecular Toxicology, Institut für umweltmedizinische Forschung gGmbH, Heinrich Heine University, Düsseldorf, Germany
| | - Ellen Fritsche
- Department of Molecular Toxicology, Institut für umweltmedizinische Forschung gGmbH, Heinrich Heine University, Düsseldorf, Germany
- Department of Dermatology, University Hospital, RWTH Aachen, Aachen, Germany
- Address correspondence to E. Fritsche, Institut für umweltmedizinische Forschung gGmbH, Heinrich Heine University, Department of Molecular Toxicology, Auf’m Hennekamp 50, 40225 Dusseldorf, Germany. Telephone: 00492113389217. Fax: 00492113190910. E-mail:
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89
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Pierre S, Bats AS, Chevallier A, Bui LC, Ambolet-Camoit A, Garlatti M, Aggerbeck M, Barouki R, Coumoul X. Induction of the Ras activator Son of Sevenless 1 by environmental pollutants mediates their effects on cellular proliferation. Biochem Pharmacol 2010; 81:304-13. [PMID: 20950586 DOI: 10.1016/j.bcp.2010.10.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 10/03/2010] [Accepted: 10/05/2010] [Indexed: 01/01/2023]
Abstract
TCDD (2,3,7,8-tetrachlorodibenzodioxin), a highly persistent environmental pollutant and a human carcinogen, is the ligand with the highest affinity for the Aryl Hydrocarbon Receptor (AhR) that induces via the AhR, xenobiotic metabolizing enzyme genes as well as several other genes. This pollutant elicits a variety of systemic toxic effects, which include cancer promotion and diverse cellular alterations that modify cell cycle progression and cell proliferation. Large-scale studies have shown that the expression of Son of Sevenless 1 (SOS1), the main mediator of Ras activation, is one of the targets of dioxin in human cultured cells. In this study, we investigated the regulation of the previously uncharacterized SOS1 gene promoter by the AhR and its ligands in the human hepatocarcinoma cell line, HepG2. We found that several environmental pollutants (AhR ligands) induce SOS1 gene expression by increasing its transcription. Chromatin immunoprecipitation experiments demonstrated that the AhR binds directly and activates the SOS1 gene promoter. We also showed that dioxin treatment leads to an activated Ras-GTP state, to ERK activation and to accelerated cellular proliferation. All these effects were mediated by SOS1 induction as shown by knock down experiments. Our data indicate that dioxin-induced cellular proliferation is mediated, at least partially, by SOS1 induction. Remarkably, our studies also suggest that SOS1 induction leads to functional effects similar to those elicited by the well-characterized oncogenic Ras mutations.
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Affiliation(s)
- Stéphane Pierre
- INSERM UMR-S 747, Toxicologie Pharmacologie et Signalisation Cellulaire, 45 rue des Saints Pères, 75006 Paris, France
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90
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Dietrich C, Kaina B. The aryl hydrocarbon receptor (AhR) in the regulation of cell-cell contact and tumor growth. Carcinogenesis 2010; 31:1319-28. [PMID: 20106901 PMCID: PMC6276890 DOI: 10.1093/carcin/bgq028] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 01/21/2010] [Accepted: 01/24/2010] [Indexed: 01/26/2023] Open
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor, which is activated by a large group of environmental pollutants including polycyclic aromatic hydrocarbons, dioxins and planar polychlorinated biphenyls. Ligand binding leads to dimerization of the AhR with aryl hydrocarbon receptor nuclear translocator and transcriptional activation of several xenobiotic phase I and phase II metabolizing enzymes, such as cytochrome P4501A1 and glutathione-S-transferase, respectively. Since phase I enzymes convert inert carcinogens to active genotoxins, the AhR plays a key role in tumor initiation. Besides this classical route, the AhR mediates tumor promotion and recent evidence suggests that the AhR also plays a role in tumor progression. To date, no mechanistic link could be established between the canonical pathway involving xenobiotic metabolism and AhR-dependent tumor promotion and progression. A hallmark of tumor promotion is unbalanced proliferation, whereas tumor progression is characterized by dedifferentiation, increased motility and metastasis of tumor cells. Tumor progression and presumably also tumor promotion are triggered by loss of cell-cell contact. Cell-cell contact is known to be a critical regulator of proliferation, differentiation and cell motility in vitro and in vivo. Increasing evidence suggests that activation of the AhR may lead to deregulation of cell-cell contact, thereby inducing unbalanced proliferation, dedifferentiation and enhanced motility. In line with this is the finding of increased AhR expression and malignancy in some animal and human cancers. Here, we summarize our current knowledge on non-canonical AhR-driven pathways being involved in deregulation of cell-cell contact and discuss the data with respect to tumor initiation, promotion and progression.
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Affiliation(s)
- Cornelia Dietrich
- Institute of Toxicology, Medical Center of the Johannes Gutenberg-University, Mainz, Germany.
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91
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Fernandez-Salguero PM. A remarkable new target gene for the dioxin receptor: The Vav3 proto-oncogene links AhR to adhesion and migration. Cell Adh Migr 2010; 4:172-5. [PMID: 20190565 DOI: 10.4161/cam.4.2.10387] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The dioxin receptor (AhR) is possibly the best characterized xenobiotic receptor because of its essential role in mediating the harmful effects of highly toxic environmental pollutants. Despite the fact that AhR-dependent toxicity is a major environmental concern, compelling evidence has recently been produced unveiling novel and remarkable endogenous functions of AhR in cell physiology and tissue homeostasis. Adding to its role in cell proliferation and differentiation, AhR is also involved in the control of cell adhesion and migration, both highly relevant tasks in development and in disease states such as cancer. Interestingly, the effect of AhR on cell migration is cell-type specific because it can sustain or slow down cell motility. Here, I will comment on our recent report showing that AhR is a positive regulator of fibroblast cells migration. Besides characterizing the phenotype of such mesenchymal cells, the most important single finding of our study is that AhR uses the cytoskeleton regulator and oncogen Vav3 to signal through small Rho GTPases, ultimately leading to the physiological control of cell adhesion and migration. These data reveal that AhR activity is required to maintain signaling pathways governing normal cell function and open the question of whether AhR plays a role in cell migration during development and in pathological conditions such as tumor metastasis.
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Affiliation(s)
- Pedro M Fernandez-Salguero
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain.
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92
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Ambolet-Camoit A, Bui LC, Pierre S, Chevallier A, Marchand A, Coumoul X, Garlatti M, Andreau K, Barouki R, Aggerbeck M. 2,3,7,8-tetrachlorodibenzo-p-dioxin counteracts the p53 response to a genotoxicant by upregulating expression of the metastasis marker agr2 in the hepatocarcinoma cell line HepG2. Toxicol Sci 2010; 115:501-12. [PMID: 20299546 DOI: 10.1093/toxsci/kfq082] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental pollutant that binds the aryl hydrocarbon receptor (AhR), a transcription factor that triggers various biological responses. In this study, we show that TCDD treatment counteracts the p53 activation (phosphorylation and acetylation) elicited by a genotoxic compound, etoposide, in the human hepatocarcinoma cell line HepG2 and we delineated the mechanisms of this interaction. Using small interfering RNA knockdown experiments, we found that the newly described metastasis marker, anterior gradient-2 (AGR2), is involved in this effect. Both AGR2 messenger RNA (mRNA) and protein levels were increased (sixfold and fourfold, respectively) by TCDD treatment, and this effect was mediated by the AhR receptor. The half-life of AGR2 mRNA was unchanged by TCDD treatment. Analysis of the promoter of the AGR2 gene revealed three putative xenobiotic-responsive elements (XREs) in the proximal 3.5-kb promoter. Transient transfection of HepG2 cells by the Gaussia luciferase reporter gene driven by various deleted and mutated fragments of the promoter indicated that only the most proximal XRE was active. Binding of the AhR to the endogenous AGR2 promoter was also triggered by TCDD treatment. These results suggest that AhR ligands such as TCDD might contribute to tumor progression by inhibiting p53 regulation (phosphorylation and acetylation) triggered by genotoxicants via the increased expression of the metastasis marker AGR2.
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93
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Bock KW, Köhle C. The mammalian aryl hydrocarbon (Ah) receptor: from mediator of dioxin toxicity toward physiological functions in skin and liver. Biol Chem 2010; 390:1225-35. [PMID: 19747074 DOI: 10.1515/bc.2009.138] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The mammalian Ah receptor (AhR) is a ligand-activated transcription factor with multiple functions in adaptive metabolism, development and dioxin toxicity in a variety of organs and cell systems. Phenotypes observed following sustained activation by dioxin or in AhR-null mice suggest organ-dependent physiological functions. These functions are probably deregulated following exposure to dioxin. We focus on skin and liver to facilitate discussion of mechanisms linking phenotypes and AhR-modulated genotypes. After a brief summary of currently discussed AhR ligand candidates, two groups of direct AhR target genes/proteins and associated functions are highlighted: (i) xenobiotic-metabolizing enzymes which are also involved in homeostasis of endogenous ligands and (ii) proteins controlling cell proliferation/apoptosis, differentiation and inflammation. Homeostatic feedback loops might not only include CYP1A1 but also Phase II enzymes such as UGT1A1 which controls the antioxidant AhR ligand bilirubin. The AhR is involved in extensive crosstalk with other transcription factors and multiple signaling pathways. Efforts elucidating the pathway toward identification of physiological functions of the AhR remain challenging and promising.
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Affiliation(s)
- Karl Walter Bock
- Department of Toxicology, Institute of Experimental and Clinical Pharmacology and Toxicology, University of Tübingen, Wilhelmstrasse 56, D-72074 Tübingen, Germany.
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94
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Barouki R, Coumoul X. Cell migration and metastasis markers as targets of environmental pollutants and the Aryl hydrocarbon receptor. Cell Adh Migr 2010; 4:72-6. [PMID: 20009531 DOI: 10.4161/cam.4.1.10313] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
During the last few years, several studies have pointed to a surprising link between environmental pollutants cellular signaling and important cell functions such as plasticity, adhesion and migration. This unexpected link could be related to endogenous functions of pollutants receptors that may be disrupted by environmental factors, which is supported by observations in invertebrate species. It could also reveal novel toxic end-points and mechanisms of those pollutants, such as teratogenesis and cancer metastasis that are highly relevant from a public health point of view. In the present short article, we will review our recent observations on the aryl hydrocarbon receptor and its new molecular and cellular targets. We identified HEF1/NEDD9/CAS-L, a multifunctional protein involved in integrin-based signaling as a transcriptional target of the receptor, and showed that its induction was critical for cell plasticity mediated by environmental pollutants. We will put our studies in perspective with other observations made by several groups.
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95
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Reyes-Hernández OD, Mejía-García A, Sánchez-Ocampo EM, Castro-Muñozledo F, Hernández-Muñoz R, Elizondo G. Aromatic hydrocarbons upregulate glyceraldehyde-3-phosphate dehydrogenase and induce changes in actin cytoskeleton. Role of the aryl hydrocarbon receptor (AhR). Toxicology 2009; 266:30-7. [PMID: 19850099 DOI: 10.1016/j.tox.2009.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 10/01/2009] [Accepted: 10/09/2009] [Indexed: 10/20/2022]
Abstract
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a multifunctional enzyme involved in several cellular functions including glycolysis, membrane transport, microtubule assembly, DNA replication and repair, nuclear RNA export, apoptosis, and the detection of nitric oxide stress. Therefore, modifications in the regulatory ability and function of GAPDH may alter cellular homeostasis. We report here that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and beta-naphthoflavone, which are well-known ligands for the aryl hydrocarbon receptor (AhR), increase GAPDH mRNA levels in vivo and in vitro, respectively. These compounds fail to induce GAPDH transcription in an AhR-null mouse model, suggesting that the increase in GAPDH level is dependent upon AhR activation. To analyse the consequences of AhR ligands on GAPDH function, mice were treated with TCDD and the level of liver activity of GAPDH was determined. The results showed that TCDD treatment increased GAPDH activity. On the other hand, treatment of Hepa-1 cells with beta-naphthoflavone leads to an increase in microfilament density when compared to untreated cultures. Collectively, these results suggest that AhR ligands, such as polycyclic hydrocarbons, can modify GAPDH expression and, therefore, have the potential to alter the multiple functions of this enzyme.
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Affiliation(s)
- O D Reyes-Hernández
- Sección Externa de Toxicología, CINVESTAV-IPN, Zacatenco, México, D.F., C.P. 07360, Mexico
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96
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Nedd9/Hef1/Cas-L mediates the effects of environmental pollutants on cell migration and plasticity. Oncogene 2009; 28:3642-51. [PMID: 19648964 DOI: 10.1038/onc.2009.224] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Aryl hydrocarbon receptor (AhR), or dioxin receptor, is a transcription factor that induces adaptive metabolic pathways in response to environmental pollutants. Recently, other pathways were found to be altered by AhR and its ligands. Indeed, developmental defects elicited by AhR ligands suggest that additional cellular functions may be targeted by this receptor, including cell migration and plasticity. Here, we show that dioxin-mediated activation of Ahr induces Nedd9/Hef1/Cas-L, a member of the Cas protein family recently identified as a metastasis marker. The Hef1 gene induction is mediated by two xenobiotic responsive elements present in this gene promoter. Moreover, using RNA interference, we show that Nedd9/Hef1/Cas-L mediates the dioxin-elicited changes related to cell plasticity, including alterations of cellular adhesion and shape, cytoskeleton reorganization, and increased cell migration. Furthermore, we show that both E-cadherin repression and Jun N-terminal kinases activation by dioxin and AhR also depend on the expression of Nedd9/Hef1/Cas-L. Our study unveils, for the first time, a link between pollutants exposure and the induced expression of a metastasis marker and shows that cellular migration and plasticity markers are regulated by AhR and its toxic ligands.
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97
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Androutsopoulos VP, Tsatsakis AM, Spandidos DA. Cytochrome P450 CYP1A1: wider roles in cancer progression and prevention. BMC Cancer 2009; 9:187. [PMID: 19531241 PMCID: PMC2703651 DOI: 10.1186/1471-2407-9-187] [Citation(s) in RCA: 282] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Accepted: 06/16/2009] [Indexed: 02/08/2023] Open
Abstract
CYP1A1 is one of the main cytochrome P450 enzymes, examined extensively for its capacity to activate compounds with carcinogenic properties. Continuous exposure to inhalation chemicals and environmental carcinogens is thought to increase the level of CYP1A1 expression in extrahepatic tissues, through the aryl hydrocarbon receptor (AhR). Although the latter has long been recognized as a ligand-induced transcription factor, which is responsible for the xenobiotic activating pathway of several phase I and phase II metabolizing enzymes, recent evidence suggests that the AhR is involved in various cell signaling pathways critical to cell cycle regulation and normal homeostasis. Disregulation of these pathways is implicated in tumor progression. In addition, it is becoming increasingly evident that CYP1A1 plays an important role in the detoxication of environmental carcinogens, as well as in the metabolic activation of dietary compounds with cancer preventative activity. Ultimately the contribution of CYP1A1 to cancer progression or prevention may depend on the balance of procarcinogen activation/detoxication and dietary natural product extrahepatic metabolism.
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Affiliation(s)
- Vasilis P Androutsopoulos
- Department of Medicine, Division of Forensic Sciences and Toxicology, University of Crete, Crete, Greece.
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98
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Collins LL, Lew BJ, Lawrence BP. TCDD exposure disrupts mammary epithelial cell differentiation and function. Reprod Toxicol 2009; 28:11-7. [PMID: 19490989 DOI: 10.1016/j.reprotox.2009.02.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Revised: 02/13/2009] [Accepted: 02/27/2009] [Indexed: 12/24/2022]
Abstract
Mammary gland growth and differentiation during pregnancy is a developmental process that is sensitive to the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). TCDD is a widespread environmental contaminant and a potent ligand for the aryl hydrocarbon receptor (AhR). We demonstrate reduced beta-casein protein induction in mouse mammary glands and in cultured SCp2 mammary epithelial cells following exposure to TCDD. SCp2 cells exposed to TCDD also show reduced cell clustering and less alveolar-like structure formation. SCp2 cells express transcriptionally active AhR, and exposure to TCDD induces expression of the AhR target gene CYP1B1. Exposure to TCDD during pregnancy reduced expression of the cell adhesion molecule E-cadherin in the mammary gland and decreased phosphorylation of STAT5, a known regulator of beta-casein gene expression. These data provide morphological and molecular evidence that TCDD-mediated AhR activation disrupts structural and functional differentiation of the mammary gland, and present an in vitro model for studying the effects of TCDD on mammary epithelial cell function.
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Affiliation(s)
- Loretta L Collins
- Department of Environmental Medicine, School of Medicine and Dentistry, University of Rochester, 601 Elmwood Avenue, Rochester, NY, USA
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99
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Carpi D, Korkalainen M, Airoldi L, Fanelli R, Hakansson H, Muhonen V, Tuukkanen J, Viluksela M, Pastorelli R. Dioxin-Sensitive Proteins in Differentiating Osteoblasts: Effects on Bone Formation In Vitro. Toxicol Sci 2009; 108:330-43. [DOI: 10.1093/toxsci/kfp021] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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100
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Carvajal-Gonzalez JM, Mulero-Navarro S, Roman AC, Sauzeau V, Merino JM, Bustelo XR, Fernandez-Salguero PM. The dioxin receptor regulates the constitutive expression of the vav3 proto-oncogene and modulates cell shape and adhesion. Mol Biol Cell 2009; 20:1715-27. [PMID: 19158396 DOI: 10.1091/mbc.e08-05-0451] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The dioxin receptor (AhR) modulates cell plasticity and migration, although the signaling involved remains unknown. Here, we report a mechanism that integrates AhR into these cytoskeleton-related functions. Immortalized and mouse embryonic fibroblasts lacking AhR (AhR-/-) had increased cell area due to spread cytoplasms that reverted to wild-type morphology upon AhR re-expression. The AhR-null phenotype included increased F-actin stress fibers, depolarized focal adhesions, and enhanced spreading and adhesion. The cytoskeleton alterations of AhR-/- cells were due to down-regulation of constitutive Vav3 expression, a guanosine diphosphate/guanosine triphosphate exchange factor for Rho/Rac GTPases and a novel transcriptional target of AhR. AhR was recruited to the vav3 promoter and maintained constitutive mRNA expression in a ligand-independent manner. Consistently, AhR-/- fibroblasts had reduced Rac1 activity and increased activation of the RhoA/Rho kinase (Rock) pathway. Pharmacological inhibition of Rac1 shifted AhR+/+ fibroblasts to the null phenotype, whereas Rock inhibition changed AhR-null cells to the AhR+/+ morphology. Knockdown of vav3 transcripts by small interfering RNA induced cytoskeleton defects and changes in adhesion and spreading mimicking those of AhR-null cells. Moreover, vav3-/- MEFs, as AhR-/- mouse embryonic fibroblasts, had increased cell area and enhanced stress fibers. By modulating Vav3-dependent signaling, AhR could regulate cell shape, adhesion, and migration under physiological conditions and, perhaps, in certain pathological states.
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Affiliation(s)
- Jose M Carvajal-Gonzalez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain
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