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Aschner M, Skalny AV, Lu R, Santamaria A, Zhou JC, Ke T, Karganov MY, Tsatsakis A, Golokhvast KS, Bowman AB, Tinkov AA. The role of hypoxia-inducible factor 1 alpha (HIF-1α) modulation in heavy metal toxicity. Arch Toxicol 2023; 97:1299-1318. [PMID: 36933023 DOI: 10.1007/s00204-023-03483-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 03/02/2023] [Indexed: 03/19/2023]
Abstract
Hypoxia-inducible factor 1 (HIF-1) is an oxygen-sensing transcriptional regulator orchestrating a complex of adaptive cellular responses to hypoxia. Several studies have demonstrated that toxic metal exposure may also modulate HIF-1α signal transduction pathway, although the existing data are scarce. Therefore, the present review aims to summarize the existing data on the effects of toxic metals on HIF-1 signaling and the potential underlying mechanisms with a special focus on prooxidant effect of the metals. The particular effect of metals was shown to be dependent on cell type, varying from down- to up-regulation of HIF-1 pathway. Inhibition of HIF-1 signaling may contribute to impaired hypoxic tolerance and adaptation, thus promoting hypoxic damage in the cells. In contrast, its metal-induced activation may result in increased tolerance to hypoxia through increased angiogenesis, thus promoting tumor growth and contributing to carcinogenic effect of heavy metals. Up-regulation of HIF-1 signaling is mainly observed upon Cr, As, and Ni exposure, whereas Cd and Hg may both stimulate and inhibit HIF-1 pathway. The mechanisms underlying the influence of toxic metal exposure on HIF-1 signaling involve modulation of prolyl hydroxylases (PHD2) activity, as well as interference with other tightly related pathways including Nrf2, PI3K/Akt, NF-κB, and MAPK signaling. These effects are at least partially mediated by metal-induced ROS generation. Hypothetically, maintenance of adequate HIF-1 signaling upon toxic metal exposure through direct (PHD2 modulation) or indirect (antioxidant) mechanisms may provide an additional strategy for prevention of adverse effects of metal toxicity.
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Affiliation(s)
- Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Anatoly V Skalny
- IM Sechenov First Moscow State Medical University (Sechenov University), 119435, Moscow, Russia
| | - Rongzhu Lu
- Department of Preventive Medicine and Public Health Laboratory Science, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Abel Santamaria
- Laboratorio de Aminoácidos Excitadores/Laboratorio de Neurofarmacología Molecular y Nanotecnología, Instituto Nacional de Neurología y Neurocirugía, 14269, Mexico City, Mexico
| | - Ji-Chang Zhou
- School of Public Health (Shenzhen), Sun Yat-Sen University, Shenzhen, 518100, China
| | - Tao Ke
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | | | - Aristides Tsatsakis
- IM Sechenov First Moscow State Medical University (Sechenov University), 119435, Moscow, Russia.,Laboratory of Toxicology, Medical School, University of Crete, Voutes, 700 13, Heraklion, Crete, Greece
| | - Kirill S Golokhvast
- Siberian Federal Scientific Centre of Agrobiotechnologies of the Russian Academy of Sciences, Krasnoobsk, Russia
| | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, USA
| | - Alexey A Tinkov
- IM Sechenov First Moscow State Medical University (Sechenov University), 119435, Moscow, Russia. .,Laboratory of Ecobiomonitoring and Quality Control, Yaroslavl State University, 150003, Yaroslavl, Russia.
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2
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NF-κB1 p50 stabilizes HIF-1α protein through suppression of ATG7-dependent autophagy. Cell Death Dis 2022; 13:1076. [PMID: 36575197 PMCID: PMC9794792 DOI: 10.1038/s41419-022-05521-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/28/2022]
Abstract
The function and underlying mechanisms of p50 in the regulation of protein expression is much less studied because of its lacking of transactivation domain. In this study, we discovered a novel function of p50 in its stabilization of hypoxia-inducible factor 1α (HIF-1α) protein under the condition of cells exposed to arsenic exposure. In p50-deficient (p50-/-) cells, the HIF-1α protein expression was impaired upon arsenic exposure, and such defect could be rescued by reconstitutional expression of p50. Mechanistic study revealed that the inhibition of autophagy-related gene 7 (ATG7)-dependent autophagy was in charge of p50-mediated HIF-1α protein stabilization following arsenic exposure. Moreover, p50 deletion promoted nucleolin (NCL) protein translation to enhance ATG7 mRNA transcription via directly binding transcription factor Sp1 mRNA and increase its stability. We further discovered that p50-mediated miR-494 upregulation gave rise to the inhibition of p50-mediated NCL translation by interacting with its 3'-UTR. These novel findings provide a great insight into the understanding of biomedical significance of p50 protein in arsenite-associated disease development and therapy.
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3
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Liu J, Niu Q, Hu Y, Ran S, Li S. The Mechanism of Trivalent Inorganic Arsenic on HIF-1α: a Systematic Review and Meta-analysis. Biol Trace Elem Res 2020; 198:449-463. [PMID: 32124230 DOI: 10.1007/s12011-020-02087-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 02/21/2020] [Indexed: 12/11/2022]
Abstract
The purpose of our study was to investigate the role of hypoxia-inducible factor-1α (HIF-1α) in arsenic-induced carcinogenesis. We included 39 articles for meta-analysis. The results showed that low-dose exposure to arsenic (≤ 10 μmol/L) could promote the expression of phosphatidylinositol 3-kinase (PI3K) and phosphorylation-protein kinase B (p-AKT). High-dose arsenic exposure (> 10 μmol/L) promoted the expression of PI3K, HIF-1α, vascular endothelial growth factor (VEGF), and p38MAPK (P38). Acute arsenic exposure (< 24 h) promoted the expression of PI3K, HIF-1α, and VEGF. Chronic arsenic exposure (≥ 24 h) promoted the expression of PI3K, p-AKT, and P38. Moreover, for normal tissue-derived cells, arsenic could induce the increased expression of PI3K, p-AKT, HIF-1α, and VEGF. For tumor tissue-derived cells, arsenic could induce the expression of PI3K, p-AKT, and P38. We found that arsenic exposure could activate the PI3K/AKT pathway, further induce the high expression of HIF-1α, and then upregulate the levels of miRNA-21 and VEGF, promote the expression of proliferating cell nuclear antigen (PCNA), and ultimately lead to malignant cell proliferation. Our findings indicated that arsenic could increase the expression of HIF-1α by activating the PI3K/AKT pathway and eventually induce malignant cell proliferation.
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Affiliation(s)
- Jiaqing Liu
- Department of Public Health, School of Medicine, Shihezi University, Shihezi, 832000, Xinjiang, China
| | - Qiang Niu
- Department of Public Health, School of Medicine, Shihezi University, Shihezi, 832000, Xinjiang, China
| | - Yunhua Hu
- Department of Public Health, School of Medicine, Shihezi University, Shihezi, 832000, Xinjiang, China
| | - Shanshan Ran
- Department of Public Health, School of Medicine, Shihezi University, Shihezi, 832000, Xinjiang, China
| | - Shugang Li
- Department of Public Health, School of Medicine, Shihezi University, Shihezi, 832000, Xinjiang, China.
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4
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Krawczyk MA, Pospieszynska A, Styczewska M, Bien E, Sawicki S, Marino Gammazza A, Fucarino A, Gorska-Ponikowska M. Extracellular Chaperones as Novel Biomarkers of Overall Cancer Progression and Efficacy of Anticancer Therapy. APPLIED SCIENCES 2020; 10:6009. [DOI: 10.3390/app10176009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Exosomal heat shock proteins (Hsps) are involved in intercellular communication both in physiological and pathological conditions. They play a role in key processes of carcinogenesis including immune system regulation, cell differentiation, vascular homeostasis and metastasis formation. Thus, exosomal Hsps are emerging biomarkers of malignancies and possible therapeutic targets. Adolescents and young adults (AYAs) are patients aged 15–39 years. This age group, placed between pediatric and adult oncology, pose a particular challenge for cancer management. New biomarkers of cancer growth and progression as well as prognostic factors are desperately needed in AYAs. In this review, we attempted to summarize the current knowledge on the role of exosomal Hsps in selected solid tumors characteristic for the AYA population and/or associated with poor prognosis in this age group. These included malignant melanoma, brain tumors, and breast, colorectal, thyroid, hepatocellular, lung and gynecological tract carcinomas. The studies on exosomal Hsps in these tumors are limited; however; some have provided promising results. Although further research is needed, there is potential for future clinical applications of exosomal Hsps in AYA cancers, both as novel biomarkers of disease presence, progression or relapse, or as therapeutic targets or tools for drug delivery.
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5
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Iglesia RP, Fernandes CFDL, Coelho BP, Prado MB, Melo Escobar MI, Almeida GHDR, Lopes MH. Heat Shock Proteins in Glioblastoma Biology: Where Do We Stand? Int J Mol Sci 2019; 20:E5794. [PMID: 31752169 PMCID: PMC6888131 DOI: 10.3390/ijms20225794] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/15/2019] [Accepted: 11/16/2019] [Indexed: 12/16/2022] Open
Abstract
Heat shock proteins (HSPs) are evolutionary conserved proteins that work as molecular chaperones and perform broad and crucial roles in proteostasis, an important process to preserve the integrity of proteins in different cell types, in health and disease. Their function in cancer is an important aspect to be considered for a better understanding of disease development and progression. Glioblastoma (GBM) is the most frequent and lethal brain cancer, with no effective therapies. In recent years, HSPs have been considered as possible targets for GBM therapy due their importance in different mechanisms that govern GBM malignance. In this review, we address current evidence on the role of several HSPs in the biology of GBMs, and how these molecules have been considered in different treatments in the context of this disease, including their activities in glioblastoma stem-like cells (GSCs), a small subpopulation able to drive GBM growth. Additionally, we highlight recent works that approach other classes of chaperones, such as histone and mitochondrial chaperones, as important molecules for GBM aggressiveness. Herein, we provide new insights into how HSPs and their partners play pivotal roles in GBM biology and may open new therapeutic avenues for GBM based on proteostasis machinery.
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Affiliation(s)
| | | | | | | | | | | | - Marilene Hohmuth Lopes
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo 05508-000, Brazil; (R.P.I.); (C.F.d.L.F.); (B.P.C.); (M.B.P.); (M.I.M.E.); (G.H.D.R.A.)
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6
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Ostrowski RP, Zhang JH. The insights into molecular pathways of hypoxia-inducible factor in the brain. J Neurosci Res 2018; 98:57-76. [PMID: 30548473 DOI: 10.1002/jnr.24366] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 11/16/2018] [Accepted: 11/20/2018] [Indexed: 12/12/2022]
Abstract
The objectives of this present work were to review recent developments on the role of hypoxia-inducible factor (HIF) in the survival of cells under normoxic versus hypoxic and inflammatory brain conditions. The dual nature of HIF effects appears well established, based on the accumulated evidence of HIF playing both the role of adaptive factor and mediator of cell demise. Cellular HIF responses depend on pathophysiological conditions, developmental phase, comorbidities, and administered medications. In addition, HIF-1α and HIF-2α actions may vary in the same tissues. The multiple roles of HIF in stem cells are emerging. HIF not only regulates expression of target genes and thereby influences resultant protein levels but also contributes to epigenetic changes that may reciprocally provide feedback regulations loops. These HIF-dependent alterations in neurological diseases and its responses to treatments in vivo need to be examined alongside with a functional status of subjects involved in such studies. The knowledge of HIF pathways might be helpful in devising HIF-mimetics and modulating drugs, acting on the molecular level to improve clinical outcomes, as exemplified here by clinical and experimental data of selected brain diseases, occasionally corroborated by the data from disorders of other organs. Because of complex role of HIF in brain injuries, prospective therapeutic interventions need to differentially target HIF responses depending on their roles in the molecular mechanisms of neurologic diseases.
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Affiliation(s)
- Robert P Ostrowski
- Department of Experimental and Clinical Neuropathology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - John H Zhang
- Departments of Anesthesiology and Physiology, School of Medicine, Loma Linda University, Loma Linda, California
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7
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Zhu J, Li Y, Tian Z, Hua X, Gu J, Li J, Liu C, Jin H, Wang Y, Jiang G, Huang H, Huang C. ATG7 Overexpression Is Crucial for Tumorigenic Growth of Bladder Cancer In Vitro and In Vivo by Targeting the ETS2/miRNA196b/FOXO1/p27 Axis. MOLECULAR THERAPY. NUCLEIC ACIDS 2017; 7:299-313. [PMID: 28624205 PMCID: PMC5415961 DOI: 10.1016/j.omtn.2017.04.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 04/07/2017] [Accepted: 04/11/2017] [Indexed: 11/28/2022]
Abstract
Human bladder cancer (BC) is the fourth most common cancer in the United States. Investigation of the strategies aiming to elucidate the tumor growth and metastatic pathways in BC is critical for the management of this disease. Here we found that ATG7 expression was remarkably elevated in human bladder urothelial carcinoma and N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced mouse invasive BC. Knockdown of ATG7 resulted in a significant inhibitory effect on tumorigenic growth of human BC cells both in vitro and in vivo by promoting p27 expression and inducing cell cycle arrest at G2/M phase. We further demonstrated that knockdown of ATG7 upregulated FOXO1 (forkhead box protein O 1) expression, which specifically promoted p27 transcription. Moreover, mechanistic studies revealed that inhibition of ATG7 stabilized ETS2 mRNA and, in turn, reduced miR-196b transcription and expression of miR-196b, which was able to bind to the 3' UTR of FOXO1 mRNA, consequently stabilizing FOXO1 mRNA and finally promoting p27 transcription and attenuating BC tumorigenic growth. The identification of the ATG7/FOXO1/p27 mechanism for promoting BC cell growth provides significant insights into understanding the nature of BC tumorigenesis. Together with our most recent discovery of the crucial role of ATG7 in promoting BC invasion, it raises the potential for developing an ATG7-based specific therapeutic strategy for treatment of human BC patients.
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Affiliation(s)
- Junlan Zhu
- Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China; Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987, USA
| | - Yang Li
- Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China; Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987, USA
| | - Zhongxian Tian
- Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Xiaohui Hua
- Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Jiayan Gu
- Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Jingxia Li
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987, USA
| | - Claire Liu
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987, USA
| | - Honglei Jin
- Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yulei Wang
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987, USA
| | - Guosong Jiang
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987, USA
| | - Haishan Huang
- Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Chuanshu Huang
- Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China; Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987, USA.
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8
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Luo F, Sun B, Li H, Xu Y, Liu Y, Liu X, Lu L, Li J, Wang Q, Wei S, Shi L, Lu X, Liu Q, Zhang A. A MALAT1/HIF-2α feedback loop contributes to arsenite carcinogenesis. Oncotarget 2016; 7:5769-87. [PMID: 26735578 PMCID: PMC4868720 DOI: 10.18632/oncotarget.6806] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 12/05/2015] [Indexed: 02/07/2023] Open
Abstract
Arsenic is well established as a human carcinogen, but the molecular mechanisms leading to arsenic-induced carcinogenesis are complex and elusive. It is also not known if lncRNAs are involved in arsenic-induced liver carcinogenesis. We have found that MALAT1, a non-coding RNA, is over-expressed in the sera of people exposed to arsenite and in hepatocellular carcinomas (HCCs), and MALAT1 has a close relation with the clinicopathological characteristics of HCC. In addition, hypoxia-inducible factor (HIF)-2α is up-regulated in HCCs, and MALAT1 and HIF-2α have a positive correlation in HCC tissues. During the malignant transformation of human hepatic epithelial (L-02) cells induced by a low concentration (2.0 μM) of arsenite, MALAT1 and HIF-2α are increased. In addition, arsenite-induced MALAT1 causes disassociation of the von Hippel-Lindau (VHL) protein from HIF-2α, therefore, alleviating VHL-mediated HIF-2α ubiquitination, which causes HIF-2α accumulation. In turn, HIF-2α transcriptionally regulates MALAT1, thus forming a positive feedback loop to ensure expression of arsenite-induced MALAT1 and HIF-2α, which are involved in malignant transformation. Moreover, MALAT1 and HIF-2α promote the invasive and metastatic capacities of arsenite-induced transformed L-02 cells and in HCC-LM3 cells. The capacities of MALAT1 and HIF-2α to promote tumor growth are validated in mouse xenograft models. In mice, arsenite induces an inflammatory response, and MALAT1 and HIF-2α are over-expressed. Together, these findings suggest that the MALAT1/HIF-2α feedback loop is involved in regulation of arsenite-induced malignant transformation. Our results not only confirm a novel mechanism involving reciprocal regulation between MALAT1 and HIF-2α, but also expand the understanding of the carcinogenic potential of arsenite.
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Affiliation(s)
- Fei Luo
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Baofei Sun
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guiyang Medical University, Guiyang 550025, Guizhou, People's Republic of China
| | - Huiqiao Li
- Department of Epidemiology and Biostatistics, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Yuan Xu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China.,Thoracic and GI Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Yi Liu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Xinlu Liu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Lu Lu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Jun Li
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guiyang Medical University, Guiyang 550025, Guizhou, People's Republic of China
| | - Qingling Wang
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guiyang Medical University, Guiyang 550025, Guizhou, People's Republic of China
| | - Shaofeng Wei
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guiyang Medical University, Guiyang 550025, Guizhou, People's Republic of China
| | - Le Shi
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Xiaolin Lu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Qizhan Liu
- Institute of Toxicology, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China.,The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University, Nanjing 211166, Jiangsu, People's Republic of China
| | - Aihua Zhang
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guiyang Medical University, Guiyang 550025, Guizhou, People's Republic of China
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9
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Yang L, Liu L, Xu Z, Liao W, Feng D, Dong X, Xu S, Xiao L, Lu J, Luo X, Tang M, Bode AM, Dong Z, Sun L, Cao Y. EBV-LMP1 targeted DNAzyme enhances radiosensitivity by inhibiting tumor angiogenesis via the JNKs/HIF-1 pathway in nasopharyngeal carcinoma. Oncotarget 2016; 6:5804-17. [PMID: 25714020 PMCID: PMC4467403 DOI: 10.18632/oncotarget.3331] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 01/03/2015] [Indexed: 02/05/2023] Open
Abstract
LMP1, which is encoded by the Epstein-Barr virus, is proposed to be one of the major oncogenic factors involved in nasopharyngeal carcinoma (NPC). Previous studies demonstrated that down-regulation of LMP1 by LMP1-targeted DNAzyme (DZ1) increases the radiosensitivity of NPC. However, the mechanism by which DZ1 contributes to this radiosensitivity remains unclear. In this study, we determined whether a DZ1 blockade of LMP1 expression has an overall positive effect on the radiotherapy of NPCs by repressing HIF-1/VEGF activity and to investigate the mechanisms underlying LMP1-induced HIF-1 activation in NPC cells. The results showed that DZ1 inhibited the microtubule-forming ability of HUVECs co-cultured with NPC cells, which occurs with the down-regulation of VEGF expression and secretion. Moreover, LMP1 increases phosphorylated JNKs/c-Jun signaling, which is involved in the regulation of HIF-1/VEGF activity. After silencing LMP1 and decreasing phosphorylation of JNKs, NPC cells exhibited an enhanced radiosensitivity. Furthermore, in vivo experiments revealed a significant inhibition of tumor growth and a marked reduction of the Ktrans parameter, which reflects the condition of tumor micro-vascular permeability. Taken together, our data suggested that VEGF expression is increased by LMP1 through the JNKs/c-Jun signaling pathway and indicated that DZ1 enhances the radiosensitivity of NPC cells by inhibiting HIF-1/VEGF activity.
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Affiliation(s)
- Lifang Yang
- Cancer Research Institute, Key Laboratory of Chinese Ministry of Education, Xiangya School of Medicine, Central South University, Changsha, China.,Center for Molecular Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Liyu Liu
- Cancer Research Institute, Key Laboratory of Chinese Ministry of Education, Xiangya School of Medicine, Central South University, Changsha, China
| | - Zhijie Xu
- Cancer Research Institute, Key Laboratory of Chinese Ministry of Education, Xiangya School of Medicine, Central South University, Changsha, China
| | - Weihua Liao
- Department of Radiology, Xiangya Hospital, Central South University, Changsha, China
| | - Deyun Feng
- Department of Pathology, Xiangya Hospital, Central South University, Changsha, China
| | - Xin Dong
- Cancer Research Institute, Key Laboratory of Chinese Ministry of Education, Xiangya School of Medicine, Central South University, Changsha, China
| | - San Xu
- Cancer Research Institute, Key Laboratory of Chinese Ministry of Education, Xiangya School of Medicine, Central South University, Changsha, China
| | - Lanbo Xiao
- Cancer Research Institute, Key Laboratory of Chinese Ministry of Education, Xiangya School of Medicine, Central South University, Changsha, China
| | - Jingchen Lu
- Cancer Research Institute, Key Laboratory of Chinese Ministry of Education, Xiangya School of Medicine, Central South University, Changsha, China
| | - Xiangjian Luo
- Cancer Research Institute, Key Laboratory of Chinese Ministry of Education, Xiangya School of Medicine, Central South University, Changsha, China
| | - Min Tang
- Cancer Research Institute, Key Laboratory of Chinese Ministry of Education, Xiangya School of Medicine, Central South University, Changsha, China
| | - Ann M Bode
- The Hormel Institute, University of Minnesota, Austin, MN, USA
| | - Zigang Dong
- The Hormel Institute, University of Minnesota, Austin, MN, USA
| | - Lunquan Sun
- Center for Molecular Medicine, Xiangya Hospital, Central South University, Changsha, China
| | - Ya Cao
- Cancer Research Institute, Key Laboratory of Chinese Ministry of Education, Xiangya School of Medicine, Central South University, Changsha, China
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10
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Wan J, Wu W, Zhang R. Local recurrence of small cell lung cancer following radiofrequency ablation is induced by HIF-1α expression in the transition zone. Oncol Rep 2015; 35:1297-308. [PMID: 26750332 PMCID: PMC4750745 DOI: 10.3892/or.2015.4541] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 12/07/2015] [Indexed: 01/25/2023] Open
Abstract
Local recurrence of lung cancer following radiofrequency ablation (RFA) treatment is common. The aims of the present study were to assess how RFA treatment affects the growth of small cell lung cancer (SCLC) micrometastases in the transition zone (TZ) surrounding the ablated region and in the reference zones (RZs) of the ablated or unablated lobes and to identify the molecular mechanism(s) of lung cancer recurrence following RFA treatment. After lung micrometastases of human SCLCs had formed, RFA treatment was applied to the right upper lobe (RUL) of the lung in nude mice. Hypoxia inducible factor (HIF)-1α expression, proliferation and angiogenesis potential both in the TZ and RZ were evaluated over time. Separately, at day 1, 7 and 14 following RFA treatment, the growth of micrometastases showed an ~2-fold increase in the TZ compared to the RZ of the unablated lobe, as the right lower lobe (RLL) and the growth of micrometastases in the RZ of the RUL was also induced by RFA. In addition, accelerated tumor growth in the TZ was induced by HIF-1α, but was not associated with tissue angiogenesis potential. We concluded that local recurrences of SCLCs caused by overproliferation of micrometastases following RFA treatment were driven by HIF-1α, although angiogenesis was not the driving force in the TZ.
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Affiliation(s)
- Jun Wan
- Department of Thoracic Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
| | - Wei Wu
- Department of Hematology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
| | - Renquan Zhang
- Department of Thoracic Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
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11
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The N-terminal region of p27 inhibits HIF-1α protein translation in ribosomal protein S6-dependent manner by regulating PHLPP-Ras-ERK-p90RSK axis. Cell Death Dis 2014; 5:e1535. [PMID: 25412313 PMCID: PMC4260754 DOI: 10.1038/cddis.2014.496] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 10/15/2014] [Accepted: 10/20/2014] [Indexed: 12/15/2022]
Abstract
P27 was identified as a tumor suppressor nearly two decades, being implicated in cell-cycle control, differentiation, senescence, apoptosis and motility. Our present study, for the first time to the best of our knowledge, revealed a potential role of p27 in inhibiting S6-mediated hypoxia-inducible factor-1α (HIF-1α) protein translation, which contributed to the protection from environmental carcinogen (sodium arsenite)-induced cell transformation. Our findings showed that depletion of p27 expression by knockout and knockdown approaches efficiently enhanced S6 phosphorylation in arsenite response via overactivating Ras/Raf/MEK/ERK pathway, which consequently resulted in the stimulation of p90RSK (90 kDa ribosomal S6 kinase), a direct kinase for S6 phosphorylation. Although PI3K/AKT pathway was also involved in S6 activation, blocking AKT and p70S6K activation did not attenuate arsenite-induced S6 activation in p27−/− cells, suggesting p27 specifically targeted Ras/ERK pathway rather than PI3K/AKT pathway for inhibition of S6 activation in response to arsenite exposure. Further functional studies found that p27 had a negative role in cell transformation induced by chronic low-dose arsentie exposure. Mechanistic investigations showed that HIF-1α translation was upregulated in p27-deficient cells in an S6 phosphorylation-dependent manner and functioned as a driving force in arsenite-induced cell transformation. Knockdown of HIF-1α efficiently reversed arsenite-induced cell transformation in p27-depleted cells. Taken together, our findings provided strong evidence showing that by targeting Ras/ERK pathway, p27 provided a negative control over HIF-1α protein synthesis in an S6-dependent manner, and abrogated arsenite-induced cell transformation via downregulation of HIF-1α translation.
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12
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Lum MA, Balaburski GM, Murphy ME, Black AR, Black JD. Heat shock proteins regulate activation-induced proteasomal degradation of the mature phosphorylated form of protein kinase C. J Biol Chem 2013; 288:27112-27127. [PMID: 23900841 DOI: 10.1074/jbc.m112.437095] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Although alterations in stimulus-induced degradation of PKC have been implicated in disease, mechanistic understanding of this process remains limited. Evidence supports the existence of both proteasomal and lysosomal mechanisms of PKC processing. An established pathway involves rate-limiting priming site dephosphorylation of the activated enzyme and proteasomal clearance of the dephosphorylated protein. However, here we show that agonists promote down-regulation of endogenous PKCα with minimal accumulation of a nonphosphorylated species in multiple cell types. Furthermore, proteasome and lysosome inhibitors predominantly protect fully phosphorylated PKCα, pointing to this form as a substrate for degradation. Failure to detect substantive dephosphorylation of activated PKCα was not due to rephosphorylation because inhibition of Hsp70/Hsc70, which is required for re-priming, had only a minor effect on agonist-induced accumulation of nonphosphorylated protein. Thus, PKC degradation can occur in the absence of dephosphorylation. Further analysis revealed novel functions for Hsp70/Hsc70 and Hsp90 in the control of agonist-induced PKCα processing. These chaperones help to maintain phosphorylation of activated PKCα but have opposing effects on degradation of the phosphorylated protein; Hsp90 is protective, whereas Hsp70/Hsc70 activity is required for proteasomal processing of this species. Notably, down-regulation of nonphosphorylated PKCα shows little Hsp70/Hsc70 dependence, arguing that phosphorylated and nonphosphorylated species are differentially targeted for proteasomal degradation. Finally, lysosomal processing of activated PKCα is not regulated by phosphorylation or Hsps. Collectively, these data demonstrate that phosphorylated PKCα is a direct target for agonist-induced proteasomal degradation via an Hsp-regulated mechanism, and highlight the existence of a novel pathway of PKC desensitization in cells.
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Affiliation(s)
- Michelle A Lum
- From The Eppley Institute, University of Nebraska Medical Center, Omaha, Nebraska 68198-5950; Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, New York 14263
| | | | | | - Adrian R Black
- From The Eppley Institute, University of Nebraska Medical Center, Omaha, Nebraska 68198-5950; Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, New York 14263
| | - Jennifer D Black
- From The Eppley Institute, University of Nebraska Medical Center, Omaha, Nebraska 68198-5950; Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, New York 14263.
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13
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Yu Y, Li J, Wan Y, Lu J, Gao J, Huang C. GADD45α induction by nickel negatively regulates JNKs/p38 activation via promoting PP2Cα expression. PLoS One 2013; 8:e57185. [PMID: 23536762 PMCID: PMC3594291 DOI: 10.1371/journal.pone.0057185] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Accepted: 01/15/2013] [Indexed: 12/20/2022] Open
Abstract
Growth arrest and DNA damage (GADD) 45α is a member of GADD inducible gene family, and is inducible in cell response to oxidative stress. GADD45α upregulation induces MKK4/JNK activation in some published experimental systems. However, we found here that the depletion of GADD45α (GADD45α−/−) in mouse embryonic fibroblasts (MEFs) resulted in an increase in the phosphorylation of MKK4/7, MKK3/6 and consequently specific up-regulated the activation of JNK/p38 and their downstream transcription factors, such as c-Jun and ATF2, in comparison to those in GADD45α+/+ MEFs cell following nickel exposure. This up-regulation of MKK-JNK/p38 pathway in GADD45α−/− cell could be rescued by the reconstitutional expression of HA-GADD45α in GADD45α−/− MEFs, GADD45α−/−(HA-GADD45α). Subsequent studies indicated that GADD45α deletion repressed expression of PP2Cα, the phosphotase of MKK3/6 and MKK4/7, whereas ectopic expression of HA-PP2Cα in GADD45α−/− cells attenuated activation of MKK3/6-p38 and MKK4/7-JNK pathways. Collectively, our results demonstrate a novel function and mechanism responsible for GADD45α regulation of MKK/MAPK pathway, further provides insight into understanding the big picture of GADD45α in the regulation of cellular responses to oxidative stress and environmental carcinogens.
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Affiliation(s)
- Yonghui Yu
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, United States of America
- Oversea Laboratory, Center for Medical Research, Wuhan University, Wuhan, Hubei, China
| | - Jingxia Li
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, United States of America
| | - Yu Wan
- Oversea Laboratory, Center for Medical Research, Wuhan University, Wuhan, Hubei, China
| | - Jianyi Lu
- Zhejiang Provincial Key Laboratory for Technology & Application of Model Organisms, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
| | - Jimin Gao
- Zhejiang Provincial Key Laboratory for Technology & Application of Model Organisms, School of Life Sciences, Wenzhou Medical College, Wenzhou, Zhejiang, China
- * E-mail: (JG); (CH)
| | - Chuanshu Huang
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, United States of America
- * E-mail: (JG); (CH)
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14
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NF-κB1 p50 promotes p53 protein translation through miR-190 downregulation of PHLPP1. Oncogene 2013; 33:996-1005. [PMID: 23396362 DOI: 10.1038/onc.2013.8] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 12/04/2012] [Accepted: 12/14/2012] [Indexed: 12/25/2022]
Abstract
The biological function of NF-κB1 (p50) in the regulation of protein expression is far from well understood owing to the lack of a transcriptional domain. Here, we report a novel function of p50 in its regulation of p53 protein translation under stress conditions. We found that the deletion of p50 (p50-/-) impaired arsenite-induced p53 protein expression, which could be restored after reconstitutive expression of HA-p50 in p50-/- cells, p50-/-(Ad-HA-p50). Further studies indicated that the amounts of p53 mRNA, p53 promoter-driven transcription activity and p53 protein degradation were comparable between wild-type and p50-/- cells. Moreover, we found that p50 was crucial for Akt/S6 ribosomal protein activation via inhibition of the translation of the PH domain and leucine-rich repeat protein phosphatases 1 (PHLPP1), a phosphatase of Akt. Further studies showed that p50-mediated upregulation of miR-190 was responsible for the inhibition of PHLPP1 translation by targeting the 3'-untranslated region of its mRNA. Collectively, we have identified a novel function of p50 in modulating p53 protein translation via regulation of the miR-190/PHLPP1/Akt-S6 ribosomal protein pathway.
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15
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Xu Y, Li Y, Li H, Pang Y, Zhao Y, Jiang R, Shen L, Zhou J, Wang X, Liu Q. The accumulations of HIF-1α and HIF-2α by JNK and ERK are involved in biphasic effects induced by different levels of arsenite in human bronchial epithelial cells. Toxicol Appl Pharmacol 2013. [DOI: 10.1016/j.taap.2012.11.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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16
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Zhang D, Li J, Zhang M, Gao G, Zuo Z, Yu Y, Zhu L, Gao J, Huang C. The requirement of c-Jun N-terminal kinase 2 in regulation of hypoxia-inducing factor-1α mRNA stability. J Biol Chem 2012; 287:34361-71. [PMID: 22910906 PMCID: PMC3464542 DOI: 10.1074/jbc.m112.365882] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 08/16/2012] [Indexed: 11/06/2022] Open
Abstract
The mRNA of hif-1α is considered as being constitutively and ubiquitously expressed, regardless of the level of oxygen tension. However many recent reports have showed that hif-1α mRNA could be regulated by natural antisense transcripts, potential microRNAs, and low O(2). In this study, it was found that a deficiency of JNK2 expression reduced HIF-1α protein induction in response to nickel treatment resulting from the impaired expression of hif-1α mRNA. Both the promoter luciferase assay and mRNA degradation assay clearly showed that depletion of JNK2 affected stability of hif-1α mRNA, rather than regulated its transcription. In addition, nucleolin, a classic histone chaperone, was demonstrated to physically bind to hif-1α mRNA and maintain its stability. Further investigation indicated that JNK2 regulated nucleolin expression and might in turn stabilize hif-1α mRNA. Collectively, we provided one more piece of evidence for the oncogenic role of JNK2 and nucleolin in regulating the cancer microenvironments by controlling HIF-1α expression.
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Affiliation(s)
- Dongyun Zhang
- From the Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York 10987 and
| | - Jingxia Li
- From the Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York 10987 and
| | - Min Zhang
- the Zhejiang Province Key Laboratory of Medical Genetics, School of Life Science, Wenzhou Medical College, Wenzhou, Zhejiang 325035, China
| | - Guangxun Gao
- From the Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York 10987 and
| | - Zhenghong Zuo
- From the Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York 10987 and
| | - Yonghui Yu
- From the Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York 10987 and
| | - Linda Zhu
- From the Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York 10987 and
| | - Jimin Gao
- the Zhejiang Province Key Laboratory of Medical Genetics, School of Life Science, Wenzhou Medical College, Wenzhou, Zhejiang 325035, China
| | - Chuanshu Huang
- From the Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, New York 10987 and
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17
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Zuo Z, Ouyang W, Li J, Costa M, Huang C. Cyclooxygenase-2 (COX-2) mediates arsenite inhibition of UVB-induced cellular apoptosis in mouse epidermal Cl41 cells. Curr Cancer Drug Targets 2012; 12:607-16. [PMID: 22463588 DOI: 10.2174/156800912801784802] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 02/24/2012] [Accepted: 02/24/2012] [Indexed: 12/29/2022]
Abstract
Inorganic arsenic is an environmental human carcinogen, and has been shown to act as a co-carcinogen with solar ultraviolet (UV) radiation in mouse skin tumor induction even at low concentrations. However, the precise mechanism of its co-carcinogenic action is largely unknown. Apoptosis plays an essential role as a protective mechanism against neoplastic development in the organism by eliminating genetically damaged cells. Thus, suppression of apoptosis is thought to contribute to carcinogenesis. It is known that cyclooxygenase-2 (COX-2) can promote carcinogenesis by inhibiting cell apoptosis under stress conditions; and our current studies investigated the potential contribution of COX-2 to the inhibitory effect of arsenite in UV-induced cell apoptosis in mouse epidermal Cl41 cells. We found that treatment of cells with low concentration (5 μM) arsenite attenuated cellular apoptosis upon UVB radiation accompanied with a coinductive effect on COX-2 expression and nuclear factor-κB (NFκB) transactivation. Our results also showed that the COX-2 induction by arsenite and UVB depended on an NFκB pathway because COX-2 co-induction could be attenuated in either p65-deficient or p50-deficient cells. Moreover, UVB-induced cell apoptosis could be dramatically reduced by the introduction of exogenous COX-2 expression, whereas the inhibitory effect of arsenite on UVB-induced cell apoptosis could be impaired in COX-2 knockdown C141 cells. Our results indicated that COX-2 mediated the anti-apoptotic effect of arsenite in UVB radiation through an NFκB-dependent pathway. Given the importance of apoptosis evasion during carcinogenesis, we anticipated that COX-2 induction might be at least partially responsible for the co-carcinogenic effect of arsenite on UVB-induced skin carcinogenesis.
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Affiliation(s)
- Z Zuo
- Nelson Institute of Environmental Medicine, New York University School of Medicine, Tuxedo, 10987, USA
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Blockade of p53 by HIF-2α, but not HIF-1α, is involved in arsenite-induced malignant transformation of human bronchial epithelial cells. Arch Toxicol 2012; 86:947-59. [PMID: 22447124 DOI: 10.1007/s00204-012-0810-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 01/31/2012] [Indexed: 12/15/2022]
Abstract
Hypoxia-inducible factors (HIFs), which consist of α and β subunits, are transcription factors involved in regulation of a variety of cellular functions. By blocking the function of the tumor suppressor p53, over-expressions of HIFs are linked to carcinogenesis and tumor progression. Inorganic arsenic, a ubiquitous environmental contaminant, is associated with an increased risk of cancer. Although there are several hypotheses regarding arsenic-induced carcinogenesis, the mechanism of action remains obscure. We have shown that long-term exposure of human bronchial epithelial (HBE) cells to a low level of arsenite increases their proliferation rate and anchorage-independent growth. When introduced into nude mice, the transformed cells are tumorigenic. The present report demonstrates that, with increased time of exposure to arsenite, there is more increased expression of HIF-2α, but not HIF-1α. These factors are known to have different functions, and, in some cases, opposite effects. Arsenite induces accumulation of HIF-2α by inhibiting its degradation through the ubiquitin-mediated proteasome pathway. HIF-2α knockdown, but not HIF-1α knockdown, increases the activation of p53. Finally, inhibition of HIF-2α blocks arsenite-induced proliferation and malignant transformation. Thus, our studies show that blockade of p53 function by inhibiting the ubiquitin-mediated proteasome degradation of HIF-2α, but not that of HIF-1α, is involved in arsenite-induced proliferation and neoplastic transformation of HBE cells.
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Ouyang DY, Ji YH, Saltis M, Xu LH, Zhang YT, Zha QB, Cai JY, He XH. Valproic acid synergistically enhances the cytotoxicity of gossypol in DU145 prostate cancer cells: an iTRTAQ-based quantitative proteomic analysis. J Proteomics 2011; 74:2180-93. [PMID: 21726675 DOI: 10.1016/j.jprot.2011.06.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2011] [Revised: 05/31/2011] [Accepted: 06/15/2011] [Indexed: 12/01/2022]
Abstract
Gossypol (GOS), a BH3 mimetic, has been investigated as a sensitizing co-therapy to radiation and chemotherapy in treatment of metastatic prostate cancer. In this study, we found that valproic acid (VPA), a histone deacetylase inhibitor (HDACI), counteracted the suppressive effect of GOS on histone H3 acetylation and enhanced the cytotoxicity of GOS to DU145 prostate cancer cells. Significant synergistic effects were observed in combined GOS and VPA treatment, culminating in more DNA damage and cell death. The iTRAQ-based quantitative proteomic analysis revealed differential proteomic profiles in cells treated with VPA, GOS or their combination. In GOS-treated cells, oxidative phosphorylation-related proteins were depressed and endoplasmic reticulum stress markers were upregulated. In the presence of VPA, the GOS-induced mitochondrial stress was further enhanced since glycolysis- and hypoxia-associated proteins were upregulated, suggesting a disruption of energy metabolism in these cells. Furthermore, the DNA damage repair ability of cells co-treated with GOS and VPA was also decreased, as evidenced by the downregulation of DNA damage repair proteins and the enhancement of DNA fragmentation and cell death. These findings suggest that GOS in combination with an HDACI has the potential to increase its clinical efficacy in the treatment of prostate cancer.
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Affiliation(s)
- Dong-yun Ouyang
- Institute of Tissue Transplantation and Immunology, Jinan University, Guangzhou 510632, China
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