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Trelford CB, Shepherd TG. LKB1 biology: assessing the therapeutic relevancy of LKB1 inhibitors. Cell Commun Signal 2024; 22:310. [PMID: 38844908 PMCID: PMC11155146 DOI: 10.1186/s12964-024-01689-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/28/2024] [Indexed: 06/10/2024] Open
Abstract
Liver Kinase B1 (LKB1), encoded by Serine-Threonine Kinase 11 (STK11), is a master kinase that regulates cell migration, polarity, proliferation, and metabolism through downstream adenosine monophosphate-activated protein kinase (AMPK) and AMPK-related kinase signalling. Since genetic screens identified STK11 mutations in Peutz-Jeghers Syndrome, STK11 mutants have been implicated in tumourigenesis labelling it as a tumour suppressor. In support of this, several compounds reduce tumour burden through upregulating LKB1 signalling, and LKB1-AMPK agonists are cytotoxic to tumour cells. However, in certain contexts, its role in cancer is paradoxical as LKB1 promotes tumour cell survival by mediating resistance against metabolic and oxidative stressors. LKB1 deficiency has also enhanced the selectivity and cytotoxicity of several cancer therapies. Taken together, there is a need to develop LKB1-specific pharmacological compounds, but prior to developing LKB1 inhibitors, further work is needed to understand LKB1 activity and regulation. However, investigating LKB1 activity is strenuous as cell/tissue type, mutations to the LKB1 signalling pathway, STE-20-related kinase adaptor protein (STRAD) binding, Mouse protein 25-STRAD binding, splicing variants, nucleocytoplasmic shuttling, post-translational modifications, and kinase conformation impact the functional status of LKB1. For these reasons, guidelines to standardize experimental strategies to study LKB1 activity, associate proteins, spliced isoforms, post-translational modifications, and regulation are of upmost importance to the development of LKB1-specific therapies. Therefore, to assess the therapeutic relevancy of LKB1 inhibitors, this review summarizes the importance of LKB1 in cell physiology, highlights contributors to LKB1 activation, and outlines the benefits and risks associated with targeting LKB1.
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Affiliation(s)
- Charles B Trelford
- The Mary &, John Knight Translational Ovarian Cancer Research Unit, London Regional Cancer Program, 790 Commissioners Road East, Room A4‑921, London, ON, N6A 4L6, Canada.
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
| | - Trevor G Shepherd
- The Mary &, John Knight Translational Ovarian Cancer Research Unit, London Regional Cancer Program, 790 Commissioners Road East, Room A4‑921, London, ON, N6A 4L6, Canada
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
- Department of Oncology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
- Department of Obstetrics and Gynaecology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
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2
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Yurttas AG, Okat Z, Elgun T, Cifci KU, Sevim AM, Gul A. Genetic deviation associated with photodynamic therapy in HeLa cell. Photodiagnosis Photodyn Ther 2023; 42:103346. [PMID: 36809810 DOI: 10.1016/j.pdpdt.2023.103346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 02/05/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023]
Abstract
Photodynamic therapy (PDT) is a method that is used in cancer treatment. The main therapeutic effect is the production of singlet oxygen (1O2). Phthalocyanines for PDT produce high singlet oxygen with absorbers of about 600-700 nm. AIM It is aimed to analyze cancer cell pathways by flow cytometry analysis and cancer-related genes with q-PCR device by applying phthalocyanine L1ZnPC, which we use as photosensitizer in photodynamic therapy, in HELA cell line. In this study, we investigate the molecular basis of L1ZnPC's anti-cancer activity. MATERIAL METHOD The cytotoxic effects of L1ZnPC, a phthalocyanine obtained from our previous study, in HELA cells were evaluated and it was determined that it led to a high rate of death as a result. The result of photodynamic therapy was analyzed using q-PCR. From the data received at the conclusion of this investigation, gene expression values were calculated, and expression levels were assessed using the 2-∆∆Ct method to examine the relative changes in these values. Cell death pathways were interpreted with the FLOW cytometer device. One-Way Analysis of Variance (ANOVA) and the Tukey-Kramer Multiple Comparison Test with Post-hoc Test were used for the statistical analysis. CONCLUSION In our study, it was observed that HELA cancer cells underwent apoptosis at a rate of 80% with drug application plus photodynamic therapy by flow cytometry method. According to q-PCR results, CT values of eight out of eighty-four genes were found to be significant and their association with cancer was evaluated. L1ZnPC is a new phthalocyanine used in this study and our findings should be supported by further studies. For this reason, different analyses are needed to be performed with this drug in different cancer cell lines. In conclusion, according to our results, this drug looks promising but still needs to be analyzed through new studies. It is necessary to examine in detail which signaling pathways they use and their mechanism of action. For this, additional experiments are required.
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Affiliation(s)
- Asiye Gok Yurttas
- Department of Biochemistry, Faculty of Pharmacy, Istanbul Health and Technology University, Istanbul, Turkey.
| | - Zehra Okat
- Department of Biochemistry, Faculty of Medicine, Marmara University, Istanbul, Turkey
| | - Tugba Elgun
- Medical Biology, Faculty of Medicine, Istanbul Biruni University, Istanbul, Turkey
| | - Kezban Ucar Cifci
- Division of Basic Sciences and Health, Hemp Research Institute, Yozgat Bozok University, Yozgat, Turkey; Department of Molecular Medicine, Institute of Health Sciences, University of Health Sciences, Turkey
| | - Altug Mert Sevim
- Department of Chemistry, Istanbul Technical University, Istanbul, Turkey
| | - Ahmet Gul
- Department of Chemistry, Istanbul Technical University, Istanbul, Turkey
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3
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Liu Y, Wang R, Su L, Zhao S, Dai X, Chen H, Wu G, Zhou H, Zheng L, Zhai Y. Integrative Proteomic and Phosphoproteomic Analyses Revealed Complex Mechanisms Underlying Reproductive Diapause in Bombus terrestris Queens. INSECTS 2022; 13:862. [PMID: 36292811 PMCID: PMC9604461 DOI: 10.3390/insects13100862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/19/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
Reproductive diapause is an overwintering strategy for Bombus terrestris, which is an important pollinator for agricultural production. However, the precise mechanisms underlying reproductive diapause in bumblebees remain largely unclear. Here, a combination analysis of proteomics and phosphoproteomics was used to reveal the mechanisms that occur during and after diapause in three different phases: diapause (D), postdiapause (PD), and founder postdiapause (FPD). In total, 4655 proteins and 10,600 phosphorylation sites of 3339 proteins were identified. Diapause termination and reactivation from D to the PD stage were characterized by the upregulation of proteins associated with ribosome assembly and biogenesis, transcription, and translation regulation in combination with the upregulation of phosphoproteins related to neural signal transmission, hormone biosynthesis and secretion, and energy-related metabolism. Moreover, the reproductive program was fully activated from PD to the FPD stage, as indicated by the upregulation of proteins related to fat digestion and absorption, the biosynthesis of unsaturated fatty acids, fatty acid elongation, protein processing in the endoplasmic reticulum, and the upregulation of energy-related metabolism at the phosphoproteome level. We also predicted a kinase-substrate interaction network and constructed protein-protein networks of proteomic and phosphoproteomic data. These results will help to elucidate the mechanisms underlying the regulation of diapause in B. terrestris for year-round mass breeding.
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Affiliation(s)
- Yan Liu
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, 23788 Gongye North Road, Jinan 250100, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan 250100, China
- Shandong Provincial Engineering Technology Research Center on Biocontrol of Crops Pests, Jinan 250100, China
| | - Ruijuan Wang
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, 23788 Gongye North Road, Jinan 250100, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan 250100, China
- Shandong Provincial Engineering Technology Research Center on Biocontrol of Crops Pests, Jinan 250100, China
| | - Long Su
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, 23788 Gongye North Road, Jinan 250100, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan 250100, China
- Shandong Provincial Engineering Technology Research Center on Biocontrol of Crops Pests, Jinan 250100, China
| | - Shan Zhao
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, 23788 Gongye North Road, Jinan 250100, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan 250100, China
- Shandong Provincial Engineering Technology Research Center on Biocontrol of Crops Pests, Jinan 250100, China
| | - Xiaoyan Dai
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, 23788 Gongye North Road, Jinan 250100, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan 250100, China
- Shandong Provincial Engineering Technology Research Center on Biocontrol of Crops Pests, Jinan 250100, China
| | - Hao Chen
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, 23788 Gongye North Road, Jinan 250100, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan 250100, China
- Shandong Provincial Engineering Technology Research Center on Biocontrol of Crops Pests, Jinan 250100, China
| | - Guang’an Wu
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan 250100, China
| | - Hao Zhou
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan 250100, China
| | - Li Zheng
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, 23788 Gongye North Road, Jinan 250100, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan 250100, China
- Shandong Provincial Engineering Technology Research Center on Biocontrol of Crops Pests, Jinan 250100, China
| | - Yifan Zhai
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, 23788 Gongye North Road, Jinan 250100, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan 250100, China
- Shandong Provincial Engineering Technology Research Center on Biocontrol of Crops Pests, Jinan 250100, China
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Liu Y, Wang Y, Li X, Jia Y, Wang J, Ao X. FOXO3a in cancer drug resistance. Cancer Lett 2022; 540:215724. [DOI: 10.1016/j.canlet.2022.215724] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/04/2022] [Accepted: 05/05/2022] [Indexed: 02/07/2023]
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Penkov S, Raghuraman BK, Erkut C, Oertel J, Galli R, Ackerman EJM, Vorkel D, Verbavatz JM, Koch E, Fahmy K, Shevchenko A, Kurzchalia TV. A metabolic switch regulates the transition between growth and diapause in C. elegans. BMC Biol 2020; 18:31. [PMID: 32188449 PMCID: PMC7081555 DOI: 10.1186/s12915-020-0760-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 02/27/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Metabolic activity alternates between high and low states during different stages of an organism's life cycle. During the transition from growth to quiescence, a major metabolic shift often occurs from oxidative phosphorylation to glycolysis and gluconeogenesis. We use the entry of Caenorhabditis elegans into the dauer larval stage, a developmentally arrested stage formed in response to harsh environmental conditions, as a model to study the global metabolic changes and underlying molecular mechanisms associated with growth to quiescence transition. RESULTS Here, we show that the metabolic switch involves the concerted activity of several regulatory pathways. Whereas the steroid hormone receptor DAF-12 controls dauer morphogenesis, the insulin pathway maintains low energy expenditure through DAF-16/FoxO, which also requires AAK-2/AMPKα. DAF-12 and AAK-2 separately promote a shift in the molar ratios between competing enzymes at two key branch points within the central carbon metabolic pathway diverting carbon atoms from the TCA cycle and directing them to gluconeogenesis. When both AAK-2 and DAF-12 are suppressed, the TCA cycle is active and the developmental arrest is bypassed. CONCLUSIONS The metabolic status of each developmental stage is defined by stoichiometric ratios within the constellation of metabolic enzymes driving metabolic flux and controls the transition between growth and quiescence.
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Affiliation(s)
- Sider Penkov
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany. .,Paul Langerhans Institute Dresden of the Helmholtz Zentrum München at the University Hospital and Faculty of Medicine Carl Gustav Carus of TU Dresden, Dresden, Germany. .,Institute for Clinical Chemistry and Laboratory Medicine, University Clinic and Medical Faculty, TU Dresden, Dresden, Germany.
| | | | - Cihan Erkut
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Present address: German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jana Oertel
- Institute of Resource Ecology at the Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Roberta Galli
- Faculty of Medicine Carl Gustav Carus, Department of Anesthesiology and Intensive Care Medicine, Clinical Sensoring and Monitoring, TU Dresden, Dresden, Germany
| | | | - Daniela Vorkel
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Jean-Marc Verbavatz
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Institut Jacques Monod, Université de Paris/CNRS, Paris, France
| | - Edmund Koch
- Faculty of Medicine Carl Gustav Carus, Department of Anesthesiology and Intensive Care Medicine, Clinical Sensoring and Monitoring, TU Dresden, Dresden, Germany
| | - Karim Fahmy
- Institute of Resource Ecology at the Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Andrej Shevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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An Y, Wang B, Wang X, Dong G, Jia J, Yang Q. SIRT1 inhibits chemoresistance and cancer stemness of gastric cancer by initiating an AMPK/FOXO3 positive feedback loop. Cell Death Dis 2020. [PMID: 32051395 DOI: 10.1038/s41419-020-2308-4.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chemotherapy is the standard care for patients with gastric cancer (GC); however, resistance to existing drugs has limited its success. The persistence of cancer stem cells (CSCs) is considered to be responsible for treatment failure. In this study, we demonstrated that SIRT1 expression was significantly downregulated in GC tissues, and that a low SIRT1 expression level indicated a poor prognosis in GC patients. We observed a suppressive role of SIRT1 in chemoresistance of GC both in vitro and in vivo. In addition, we found that SIRT1 eliminated CSC properties of GC cells. Mechanistically, SIRT1 exerted inhibitory activities on chemoresistance and CSC properties through FOXO3 and AMPK. Furthermore, a synergistic effect was revealed between FOXO3 and AMPK. AMPK promoted nuclear translocation of FOXO3 and enhanced its transcriptional activities. In addition, FOXO3 increased the expression level and activation of AMPKα by directly binding to its promoter and activating the transcription of AMPKα. Similar to SIRT1, low expression levels of p-AMPKα and FOXO3a are also related to the poor prognosis of GC patients. Moreover, we revealed a correlation between the expression levels of SIRT1, p-AMPKα, and FOXO3a. These findings indicated the importance of the SIRT1-AMPK/FOXO3 pathway in reversing chemoresistance and CSC properties of GC. Thus, exploring efficient strategies to activate the SIRT1-AMPK/FOXO3 pathway may lead to improving the survival of GC patients.
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Affiliation(s)
- Yifei An
- Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China
| | - Bo Wang
- Department of Traditional Medicine, Qilu Hospital, Shandong University, Jinan, 250012, China
| | - Xin Wang
- Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China
| | - Guoying Dong
- Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China
| | - Jihui Jia
- Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China.,Key Laboratory for Experimental Teratology of the Chinese Ministry of Education, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China.,Cancer Research Laboratory, Shandong University, Karolinska Institute Collaborative Laboratory, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China
| | - Qing Yang
- Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China. .,Key Laboratory for Experimental Teratology of the Chinese Ministry of Education, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China. .,Cancer Research Laboratory, Shandong University, Karolinska Institute Collaborative Laboratory, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China.
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7
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An Y, Wang B, Wang X, Dong G, Jia J, Yang Q. SIRT1 inhibits chemoresistance and cancer stemness of gastric cancer by initiating an AMPK/FOXO3 positive feedback loop. Cell Death Dis 2020; 11:115. [PMID: 32051395 PMCID: PMC7015918 DOI: 10.1038/s41419-020-2308-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 01/25/2020] [Accepted: 01/27/2020] [Indexed: 02/07/2023]
Abstract
Chemotherapy is the standard care for patients with gastric cancer (GC); however, resistance to existing drugs has limited its success. The persistence of cancer stem cells (CSCs) is considered to be responsible for treatment failure. In this study, we demonstrated that SIRT1 expression was significantly downregulated in GC tissues, and that a low SIRT1 expression level indicated a poor prognosis in GC patients. We observed a suppressive role of SIRT1 in chemoresistance of GC both in vitro and in vivo. In addition, we found that SIRT1 eliminated CSC properties of GC cells. Mechanistically, SIRT1 exerted inhibitory activities on chemoresistance and CSC properties through FOXO3 and AMPK. Furthermore, a synergistic effect was revealed between FOXO3 and AMPK. AMPK promoted nuclear translocation of FOXO3 and enhanced its transcriptional activities. In addition, FOXO3 increased the expression level and activation of AMPKα by directly binding to its promoter and activating the transcription of AMPKα. Similar to SIRT1, low expression levels of p-AMPKα and FOXO3a are also related to the poor prognosis of GC patients. Moreover, we revealed a correlation between the expression levels of SIRT1, p-AMPKα, and FOXO3a. These findings indicated the importance of the SIRT1-AMPK/FOXO3 pathway in reversing chemoresistance and CSC properties of GC. Thus, exploring efficient strategies to activate the SIRT1-AMPK/FOXO3 pathway may lead to improving the survival of GC patients.
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Affiliation(s)
- Yifei An
- Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China
| | - Bo Wang
- Department of Traditional Medicine, Qilu Hospital, Shandong University, Jinan, 250012, China
| | - Xin Wang
- Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China
| | - Guoying Dong
- Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China
| | - Jihui Jia
- Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China.,Key Laboratory for Experimental Teratology of the Chinese Ministry of Education, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China.,Cancer Research Laboratory, Shandong University, Karolinska Institute Collaborative Laboratory, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China
| | - Qing Yang
- Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China. .,Key Laboratory for Experimental Teratology of the Chinese Ministry of Education, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China. .,Cancer Research Laboratory, Shandong University, Karolinska Institute Collaborative Laboratory, School of Basic Medical Sciences, Shandong University, Jinan, 250012, China.
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8
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Miller VJ, Villamena FA, Volek JS. Nutritional Ketosis and Mitohormesis: Potential Implications for Mitochondrial Function and Human Health. J Nutr Metab 2018; 2018:5157645. [PMID: 29607218 PMCID: PMC5828461 DOI: 10.1155/2018/5157645] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 12/27/2017] [Indexed: 02/07/2023] Open
Abstract
Impaired mitochondrial function often results in excessive production of reactive oxygen species (ROS) and is involved in the etiology of many chronic diseases, including cardiovascular disease, diabetes, neurodegenerative disorders, and cancer. Moderate levels of mitochondrial ROS, however, can protect against chronic disease by inducing upregulation of mitochondrial capacity and endogenous antioxidant defense. This phenomenon, referred to as mitohormesis, is induced through increased reliance on mitochondrial respiration, which can occur through diet or exercise. Nutritional ketosis is a safe and physiological metabolic state induced through a ketogenic diet low in carbohydrate and moderate in protein. Such a diet increases reliance on mitochondrial respiration and may, therefore, induce mitohormesis. Furthermore, the ketone β-hydroxybutyrate (BHB), which is elevated during nutritional ketosis to levels no greater than those resulting from fasting, acts as a signaling molecule in addition to its traditionally known role as an energy substrate. BHB signaling induces adaptations similar to mitohormesis, thereby expanding the potential benefit of nutritional ketosis beyond carbohydrate restriction. This review describes the evidence supporting enhancement of mitochondrial function and endogenous antioxidant defense in response to nutritional ketosis, as well as the potential mechanisms leading to these adaptations.
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Affiliation(s)
- Vincent J. Miller
- Department of Human Sciences, College of Education and Human Ecology, The Ohio State University, Columbus, OH, USA
| | - Frederick A. Villamena
- Department of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Jeff S. Volek
- Department of Human Sciences, College of Education and Human Ecology, The Ohio State University, Columbus, OH, USA
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9
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Kjøbsted R, Hingst JR, Fentz J, Foretz M, Sanz MN, Pehmøller C, Shum M, Marette A, Mounier R, Treebak JT, Wojtaszewski JFP, Viollet B, Lantier L. AMPK in skeletal muscle function and metabolism. FASEB J 2018; 32:1741-1777. [PMID: 29242278 PMCID: PMC5945561 DOI: 10.1096/fj.201700442r] [Citation(s) in RCA: 269] [Impact Index Per Article: 44.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Skeletal muscle possesses a remarkable ability to adapt to various physiologic conditions. AMPK is a sensor of intracellular energy status that maintains energy stores by fine-tuning anabolic and catabolic pathways. AMPK’s role as an energy sensor is particularly critical in tissues displaying highly changeable energy turnover. Due to the drastic changes in energy demand that occur between the resting and exercising state, skeletal muscle is one such tissue. Here, we review the complex regulation of AMPK in skeletal muscle and its consequences on metabolism (e.g., substrate uptake, oxidation, and storage as well as mitochondrial function of skeletal muscle fibers). We focus on the role of AMPK in skeletal muscle during exercise and in exercise recovery. We also address adaptations to exercise training, including skeletal muscle plasticity, highlighting novel concepts and future perspectives that need to be investigated. Furthermore, we discuss the possible role of AMPK as a therapeutic target as well as different AMPK activators and their potential for future drug development.—Kjøbsted, R., Hingst, J. R., Fentz, J., Foretz, M., Sanz, M.-N., Pehmøller, C., Shum, M., Marette, A., Mounier, R., Treebak, J. T., Wojtaszewski, J. F. P., Viollet, B., Lantier, L. AMPK in skeletal muscle function and metabolism.
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Affiliation(s)
- Rasmus Kjøbsted
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Janne R Hingst
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Joachim Fentz
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Marc Foretz
- INSERM, Unité 1016, Institut Cochin, Paris, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Maria-Nieves Sanz
- Department of Cardiovascular Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland, and.,Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Christian Pehmøller
- Internal Medicine Research Unit, Pfizer Global Research and Development, Cambridge, Massachusetts, USA
| | - Michael Shum
- Axe Cardiologie, Quebec Heart and Lung Research Institute, Laval University, Québec, Canada.,Institute for Nutrition and Functional Foods, Laval University, Québec, Canada
| | - André Marette
- Axe Cardiologie, Quebec Heart and Lung Research Institute, Laval University, Québec, Canada.,Institute for Nutrition and Functional Foods, Laval University, Québec, Canada
| | - Remi Mounier
- Institute NeuroMyoGène, Université Claude Bernard Lyon 1, INSERM Unité 1217, CNRS UMR, Villeurbanne, France
| | - Jonas T Treebak
- Section of Integrative Physiology, Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen F P Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Benoit Viollet
- INSERM, Unité 1016, Institut Cochin, Paris, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Louise Lantier
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA.,Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, Tennessee, USA
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10
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Kumazoe M, Takai M, Hiroi S, Takeuchi C, Kadomatsu M, Nojiri T, Onda H, Bae J, Huang Y, Takamatsu K, Yamashita S, Kangawa K, Tachibana H. The FOXO3/PGC-1β signaling axis is essential for cancer stem cell properties of pancreatic ductal adenocarcinoma. J Biol Chem 2017; 292:10813-10823. [PMID: 28507102 PMCID: PMC5491768 DOI: 10.1074/jbc.m116.772111] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 05/11/2017] [Indexed: 12/20/2022] Open
Abstract
In 95% of patients with pancreatic ductal adenocarcinoma, recurrence is observed following chemotherapy. Findings from several studies have indicated that cancer stem cells (CSCs) are resistant to anticancer agents and may be involved in cancer recurrence and metastasis. The CD44 protein is a major CSC marker, and CD44 also plays an indispensable role in the CSC properties in several cancers, including pancreatic cancer; however, no clinical approach exists to inhibit CD44 activity. Here, we have performed knock-in/knockdown experiments, and we demonstrate that the forkhead box O3 (FOXO3)/liver kinase B1 (LKB1)/AMP-activated protein kinase/peroxisome proliferator-activated receptor-γ co-activator-1β (PGC-1β)/pyruvate dehydrogenase-A1 pathway is essential for CD44 expression and CSC properties. We observed that patients exhibiting high pyruvate dehydrogenase-A1 expression have a poor prognosis. Systemic PGC-1β knock-out mice are fertile and viable and do not exhibit an overt phenotype under normal conditions. This suggests that cGMP induction and PGC-1β inhibition represent potential strategies for treating patients with pancreatic ductal adenocarcinoma.
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Affiliation(s)
- Motofumi Kumazoe
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan and
- the Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita-City, Osaka 565-8565, Japan
| | - Mika Takai
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan and
| | - Shun Hiroi
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan and
| | - Chieri Takeuchi
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan and
| | - Mai Kadomatsu
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan and
| | - Takashi Nojiri
- the Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita-City, Osaka 565-8565, Japan
| | - Hiroaki Onda
- the Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita-City, Osaka 565-8565, Japan
| | - Jaehoon Bae
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan and
| | - Yuhui Huang
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan and
| | - Kanako Takamatsu
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan and
| | - Shuya Yamashita
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan and
| | - Kenji Kangawa
- the Department of Biochemistry, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita-City, Osaka 565-8565, Japan
| | - Hirofumi Tachibana
- From the Division of Applied Biological Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan and
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11
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Guo J, Kong LM, Peng AF, Long XH, Zhou Y, Shu Y. Transcription factor NF‑YA promotes a malignant phenotype by upregulating fatty acid synthase expression. Mol Med Rep 2016; 14:5007-5014. [PMID: 27840951 PMCID: PMC5355697 DOI: 10.3892/mmr.2016.5897] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 09/14/2016] [Indexed: 11/06/2022] Open
Abstract
Recent studies have revealed that increased expression of the alpha subunit of nuclear transcription factor Y (NF‑YA) is associated with the malignant phenotype of various tumors. However, whether elevated expression of NF‑YA promotes a malignant phenotype in osteosarcoma (OS), and the molecular mechanisms underlying this predicted effect is currently unknown. In the present study, small hairpin RNA (shRNA)‑mediated knockdown of endogenous NF‑YA significantly inhibited the migration and invasion capabilities of OS cells in vitro, whereas ectopic expression of NF‑YA increased the migration and invasion capabilities of these cells. In addition, the induction of upregulated NF‑YA expression on the malignant phenotype of OS cells was attenuated by silencing fatty acid synthase (FASN) expression. Furthermore, the expression level of FASN was increased by upregulating NF‑YA, while decreased FASN expression was observed following NF‑YA silencing in OS cells. The results of the present study suggest that NF‑YA may promote a malignant phenotype in OS cells, in part, by activating the FASN signaling pathway, which may represent a promising target for the management of OS.
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Affiliation(s)
- Jing Guo
- Department of Oral and Maxillofacial Surgery, The Affiliated Stomatological Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Ling Min Kong
- Department of Orthopedics, The Central People's Hospital of Ji'an City, Ji'an, Jiangxi 343000, P.R. China
| | - Ai Fen Peng
- Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330004, P.R. China
| | - Xin Hua Long
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Yang Zhou
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Yong Shu
- Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
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12
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Post-translational modifications of FOXO family proteins. Mol Med Rep 2016; 14:4931-4941. [DOI: 10.3892/mmr.2016.5867] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 09/21/2016] [Indexed: 12/30/2022] Open
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13
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Hasche D, Stephan S, Savelyeva L, Westermann F, Rösl F, Vinzón SE. Establishment of an Immortalized Skin Keratinocyte Cell Line Derived from the Animal Model Mastomys coucha. PLoS One 2016; 11:e0161283. [PMID: 27533138 PMCID: PMC4988767 DOI: 10.1371/journal.pone.0161283] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/02/2016] [Indexed: 11/18/2022] Open
Abstract
In the present report we describe the establishment of a spontaneous immortalized skin keratinocyte cell line derived from the skin of the multimammate rodent Mastomys coucha. These animals are used in preclinical studies for a variety of human diseases such as infections with nematodes, bacteria and papillomaviruses, especially regarding cutaneous manifestations such as non-melanoma skin cancer. Here we characterize the cells in terms of their origin and cytogenetic features. Searching for genomic signatures, a spontaneous mutation in the splicing donor sequence of Trp53 (G to A transition at the first position of intron 7) could be detected. This point mutation leads to alternative splicing and to a premature stop codon, resulting in a truncated and, in turn, undetectable form of p53, probably contributing to the process of immortalization. Mastomys coucha-derived skin keratinocytes can be used as an in vitro system to investigate molecular and immunological aspects of infectious agent interactions with their host cells.
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Affiliation(s)
- Daniel Hasche
- Division of Viral Transformation Mechanisms (F030), German Cancer Research Center, Heidelberg, Germany
| | - Sonja Stephan
- Division of Viral Transformation Mechanisms (F030), German Cancer Research Center, Heidelberg, Germany
| | - Larissa Savelyeva
- Division of Neuroblastoma Genomics (B087), German Cancer Research Center, Heidelberg, Germany
| | - Frank Westermann
- Division of Neuroblastoma Genomics (B087), German Cancer Research Center, Heidelberg, Germany
| | - Frank Rösl
- Division of Viral Transformation Mechanisms (F030), German Cancer Research Center, Heidelberg, Germany
- * E-mail: ; (SEV); (FR)
| | - Sabrina E. Vinzón
- Division of Viral Transformation Mechanisms (F030), German Cancer Research Center, Heidelberg, Germany
- * E-mail: ; (SEV); (FR)
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14
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Alcalá-Corona SA, Velázquez-Caldelas TE, Espinal-Enríquez J, Hernández-Lemus E. Community Structure Reveals Biologically Functional Modules in MEF2C Transcriptional Regulatory Network. Front Physiol 2016; 7:184. [PMID: 27252657 PMCID: PMC4878384 DOI: 10.3389/fphys.2016.00184] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 05/06/2016] [Indexed: 01/04/2023] Open
Abstract
Gene regulatory networks are useful to understand the activity behind the complex mechanisms in transcriptional regulation. A main goal in contemporary biology is using such networks to understand the systemic regulation of gene expression. In this work, we carried out a systematic study of a transcriptional regulatory network derived from a comprehensive selection of all potential transcription factor interactions downstream from MEF2C, a human transcription factor master regulator. By analyzing the connectivity structure of such network, we were able to find different biologically functional processes and specific biochemical pathways statistically enriched in communities of genes into the network, such processes are related to cell signaling, cell cycle and metabolism. In this way we further support the hypothesis that structural properties of biological networks encode an important part of their functional behavior in eukaryotic cells.
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Affiliation(s)
- Sergio A Alcalá-Corona
- Computational Genomics Department, National Institute of Genomic MedicineMexico City, Mexico; Complexity in Systems Biology, Center for Complexity Sciences, Universidad Nacional Autónoma de MéxicoMexico City, Mexico
| | | | - Jesús Espinal-Enríquez
- Computational Genomics Department, National Institute of Genomic MedicineMexico City, Mexico; Complexity in Systems Biology, Center for Complexity Sciences, Universidad Nacional Autónoma de MéxicoMexico City, Mexico
| | - Enrique Hernández-Lemus
- Computational Genomics Department, National Institute of Genomic MedicineMexico City, Mexico; Complexity in Systems Biology, Center for Complexity Sciences, Universidad Nacional Autónoma de MéxicoMexico City, Mexico
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15
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Yuan Y, Cruzat VF, Newsholme P, Cheng J, Chen Y, Lu Y. Regulation of SIRT1 in aging: Roles in mitochondrial function and biogenesis. Mech Ageing Dev 2016; 155:10-21. [DOI: 10.1016/j.mad.2016.02.003] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 12/28/2015] [Accepted: 02/05/2016] [Indexed: 12/13/2022]
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16
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Shorning BY, Clarke AR. Energy sensing and cancer: LKB1 function and lessons learnt from Peutz-Jeghers syndrome. Semin Cell Dev Biol 2016; 52:21-9. [PMID: 26877140 DOI: 10.1016/j.semcdb.2016.02.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/08/2016] [Accepted: 02/08/2016] [Indexed: 12/31/2022]
Abstract
We describe in this review increasing evidence that loss of LKB1 kinase in Peutz-Jeghers syndrome (PJS) derails the existing natural balance between cell survival and tumour growth suppression. LKB1 deletion can plunge cells into an energy/oxidative stress-induced crisis which leads to the activation of alternative and often carcinogenic pathways to maintain cellular energy levels. It therefore appears that although LKB1 deficiency can suppress oncogenic transformation in the short term, it can ultimately lead to more progressed and malignant phenotypes by driving abnormal cell differentiation, genomic instability and increased tumour heterogeneity.
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Affiliation(s)
- Boris Y Shorning
- European Cancer Stem Cell Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, United Kingdom.
| | - Alan R Clarke
- European Cancer Stem Cell Research Institute, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, United Kingdom
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17
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Histone deacetylase inhibition protects hearing against acute ototoxicity by activating the Nf- κB pathway. Cell Death Discov 2015; 1. [PMID: 26279947 PMCID: PMC4536828 DOI: 10.1038/cddiscovery.2015.12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Auditory hair cells have repeatedly been shown to be susceptible to ototoxicity from a multitude of drugs including aminoglycoside antibiotics. Here, we found that systemic HDAC inhibition using suberoylanilide hydroxamic acid (SAHA) on adult mice offers almost complete protection against hair cell loss and hearing threshold shifts from acute ototoxic insult from kanamycin potentiated with furosemide. We also found that the apparent lack of hair cell loss was completely independent of spontaneous or facilitated (ectopic Atoh1 induction) hair cell regeneration. Rather, SAHA treatment correlated with RelA acetylation (K310) and subsequent activation of the Nf-κB pro-survival pathway leading to expression of pro-survival genes such as Cflar (cFLIP) and Bcl2l1 (Bcl-xL). In addition, we also detected increased expression of pro-survival genes Cdkn1a (p21) and Hspa1a (Hsp70), and decreased expression of the pro-apoptosis gene Bcl2l11 (Bim). These data combined provide evidence that class I HDACs control the transcriptional activation of pro-survival pathways in response to ototoxic insult by regulating the acetylation status of transcription factors found at the crossroads of cell death and survival in the mammalian inner ear.
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18
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Sun J, Zhao M, Jia P, Wang L, Wu Y, Iverson C, Zhou Y, Bowton E, Roden DM, Denny JC, Aldrich MC, Xu H, Zhao Z. Deciphering Signaling Pathway Networks to Understand the Molecular Mechanisms of Metformin Action. PLoS Comput Biol 2015; 11:e1004202. [PMID: 26083494 PMCID: PMC4470683 DOI: 10.1371/journal.pcbi.1004202] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 02/13/2015] [Indexed: 12/15/2022] Open
Abstract
A drug exerts its effects typically through a signal transduction cascade, which is non-linear and involves intertwined networks of multiple signaling pathways. Construction of such a signaling pathway network (SPNetwork) can enable identification of novel drug targets and deep understanding of drug action. However, it is challenging to synopsize critical components of these interwoven pathways into one network. To tackle this issue, we developed a novel computational framework, the Drug-specific Signaling Pathway Network (DSPathNet). The DSPathNet amalgamates the prior drug knowledge and drug-induced gene expression via random walk algorithms. Using the drug metformin, we illustrated this framework and obtained one metformin-specific SPNetwork containing 477 nodes and 1,366 edges. To evaluate this network, we performed the gene set enrichment analysis using the disease genes of type 2 diabetes (T2D) and cancer, one T2D genome-wide association study (GWAS) dataset, three cancer GWAS datasets, and one GWAS dataset of cancer patients with T2D on metformin. The results showed that the metformin network was significantly enriched with disease genes for both T2D and cancer, and that the network also included genes that may be associated with metformin-associated cancer survival. Furthermore, from the metformin SPNetwork and common genes to T2D and cancer, we generated a subnetwork to highlight the molecule crosstalk between T2D and cancer. The follow-up network analyses and literature mining revealed that seven genes (CDKN1A, ESR1, MAX, MYC, PPARGC1A, SP1, and STK11) and one novel MYC-centered pathway with CDKN1A, SP1, and STK11 might play important roles in metformin’s antidiabetic and anticancer effects. Some results are supported by previous studies. In summary, our study 1) develops a novel framework to construct drug-specific signal transduction networks; 2) provides insights into the molecular mode of metformin; 3) serves a model for exploring signaling pathways to facilitate understanding of drug action, disease pathogenesis, and identification of drug targets. A deep understanding of a drug’s mechanisms of actions is essential not only in the discovery of new treatments but also in minimizing adverse effects. Here, we develop a computational framework, the Drug-specific Signaling Pathway Network (DSPathNet), to reconstruct a comprehensive signaling pathway network (SPNetwork) impacted by a particular drug. To illustrate this computational approach, we used metformin, an anti-diabetic drug, as an example. Starting from collecting the metformin-related upstream genes and inferring the metformin-related downstream genes, we built one metformin-specific SPNetwork via random walk based algorithms. Our evaluation of the metformin-specific SPNetwork by using disease genes and genotyping data from genome-wide association studies showed that our DSPathNet approach was efficient to synopsize drug’s key components and their relationship involved in the type 2 diabetes and cancer, even the metformin anticancer activity. This work presents a novel computational framework for constructing individual drug-specific signal transduction networks. Furthermore, its successful application to the drug metformin provides some valuable insights into the mode of metformin action, which will facilitate our understanding of the molecular mechanisms underlying drug treatments, disease pathogenesis, and identification of novel drug targets and repurposed drugs.
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Affiliation(s)
- Jingchun Sun
- School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, Texas, United States of America
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Min Zhao
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Peilin Jia
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Lily Wang
- Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Yonghui Wu
- School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Carissa Iverson
- Department of Thoracic Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Center for Human Genetics Research, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Yubo Zhou
- National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, People’s Republic of China
| | - Erica Bowton
- Institute for Clinical and Translational Research, School of Medicine, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Dan M. Roden
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Joshua C. Denny
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Melinda C. Aldrich
- Department of Thoracic Surgery, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Center for Human Genetics Research, Vanderbilt University, Nashville, Tennessee, United States of America
- Division of Epidemiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Hua Xu
- School of Biomedical Informatics, The University of Texas Health Science Center at Houston, Houston, Texas, United States of America
- * E-mail: (HX); (ZZ)
| | - Zhongming Zhao
- Department of Biomedical Informatics, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Center for Quantitative Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- * E-mail: (HX); (ZZ)
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19
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Liu T, Qin W, Hou L, Huang Y. MicroRNA-17 promotes normal ovarian cancer cells to cancer stem cells development via suppression of the LKB1-p53-p21/WAF1 pathway. Tumour Biol 2014; 36:1881-93. [PMID: 25510663 DOI: 10.1007/s13277-014-2790-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 10/29/2014] [Indexed: 01/06/2023] Open
Abstract
The mechanism underlying the development of human ovarian cancer is poorly understood. The liver kinase protein, LKB1, is hypothesized to play a pivotal role in tumor cell proliferation and invasion capacity through regulation of p53 and p21/WAF1 expression. Previous studies suggest LKB1 may, in turn, be regulated by microRNA-17. Here, we examined the role of miR-17 in the expression of LKB1 and the downstream effects on proliferation and invasion capacity of normal ovarian cancer cells (OCCs) and ovarian stem cells. In this study, both the mRNA and protein expression levels of LKB1, p53, and p21 decreased in OCCs following transfection with a miR-17 expression plasmid. MiR-17 expression affected cell cycle regulation and stimulated the proliferation and invasion capacity of OCCs in vitro. ChIP assays indicated that the binding efficiency of p53 to the p21/WAF1 gene promoter was much lower in miR-17 transfected OCCs than in OCCs transfected with a mutated miR-17. Co-immunoprecipitation and western blotting showed significantly lower levels of p53 and p53 Ser15-pho in the miR-17 transfected OCCs as compared to the mutant miR-17 transfected OCCs. Xenograft experiments confirmed that suppression of tumor growth in vivo occurred in the absence of functional miR-17. These findings suggest that mature miR-17 expression may have an important role in the pathogenesis of human ovarian tumors through its interference with the LKB1-p53-p21/WAF1 pathway expression by epigenetic modification. These findings are of potential importance in the identification of novel therapeutic targets in human ovarian cancer.
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Affiliation(s)
- Te Liu
- Shanghai Tenth People's Hospital, Medical School, Tongji University, Shanghai, 200072, China,
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20
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Liang X, Li ZL, Jiang LL, Guo QQ, Liu MJ, Nan KJ. Suppression of lung cancer cell invasion by LKB1 is due to the downregulation of tissue factor and vascular endothelial growth factor, partly dependent on SP1. Int J Oncol 2014; 44:1989-97. [PMID: 24647869 DOI: 10.3892/ijo.2014.2351] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 02/19/2014] [Indexed: 11/05/2022] Open
Abstract
LKB1 encodes a serine/threonine kinase generally inactivated in many human cancers, which mediates cancer cell proliferation, migration and differentiation. Recent studies indicated that LKB1 exhibits potent anti-metastatic activity. However, the underlying molecular mechanisms of this activity remain unclear. In this study, we re‑introduced LKB1 into A549 lung cancer cells that lack the LKB1 gene to investigate how LKB1 affects tumor invasiveness and metastasis. We demonstrated that overexpression of the LKB1 protein in lung cancer cells resulted in significant inhibition of invasion. Furthermore, transfected lung cancer cells with LKB1 suppressed tissue factor (TF) and vascular endothelial growth factor (VEGF) expression at both the mRNA and protein levels. Here, we provided evidence showing that downregulation of TF and VEGF by LKB1 is correlated well with the inhibition of cell invasion. Overexpression of the LKB1 protein in human lung cancer is significantly associated with a decrease in activity and expression of the transcription factor SP1. Constitutive activation of the transcription factor Sp1 plays a critical role in TF and VEGF overexpression. We conclude that suppression of lung cancer cell invasion by LKB1 through downregulation of TF and VEGF may partly depend on its inhibitory effect on the transcription factor Sp1. Collectively, our data provide a novel molecular mechanism for the antitumor activity of LKB1 and may help further improve its effectiveness in controlling lung cancer growth and invasion.
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Affiliation(s)
- Xuan Liang
- Department of Oncology, First Affiliated Hospital, Xi'an Jiaotong University Medical College, Xi'an, Shaanxi 710061, P.R. China
| | - Zhao-Lun Li
- Department of Urology, Second Affiliated Hospital, Xi'an Jiaotong University Medical College, Xi'an, Shaanxi 710061, P.R. China
| | - Li-Li Jiang
- Department of Oncology, First Affiliated Hospital, Xi'an Jiaotong University Medical College, Xi'an, Shaanxi 710061, P.R. China
| | - Qian-Qian Guo
- Department of Oncology, First Affiliated Hospital, Xi'an Jiaotong University Medical College, Xi'an, Shaanxi 710061, P.R. China
| | - Meng-Jie Liu
- Department of Oncology, First Affiliated Hospital, Xi'an Jiaotong University Medical College, Xi'an, Shaanxi 710061, P.R. China
| | - Ke-Jun Nan
- Department of Oncology, First Affiliated Hospital, Xi'an Jiaotong University Medical College, Xi'an, Shaanxi 710061, P.R. China
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21
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Park HJ, Choi JH. Identification and Functional Characterization of Novel Genetic Variations in the OCTN1 Promoter. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2014; 18:169-75. [PMID: 24757380 PMCID: PMC3994305 DOI: 10.4196/kjpp.2014.18.2.169] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 03/02/2014] [Accepted: 03/03/2014] [Indexed: 01/27/2023]
Abstract
Human organic cation/carnitine transporter 1 (OCTN1) plays an important role in the transport of drugs and endogenous substances. It is known that a missense variant of OCTN1 is significantly associated with Crohn's disease susceptibility. This study was performed to identify genetic variants of the OCTN1 promoter in Korean individuals and to determine their functional effects. First, the promoter region of OCTN1 was directly sequenced using genomic DNA samples from 48 healthy Koreans. OCTN1 promoter activity was then measured using a luciferase reporter assay in HCT-116 cells. Seven variants of the OCTN1 promoter were identified, two of which were novel. There were also four major OCTN1 promoter haplotypes. Three haplotypes (H1, H3, and H4) showed decreased transcriptional activity, which was reduced by 22.9%, 23.0%, and 44.6%, respectively (p<0.001), compared with the reference haplotype (H2). Transcription factor binding site analyses and gel shift assays revealed that NF-Y could bind to the region containing g.-1875T>A, a variant present in H3, and that the binding affinity of NF-Y was higher for the g.-1875T allele than for the g.-1875A allele. NF-Y could also repress OCTN1 transcription. These data suggest that three OCTN1 promoter haplotypes could regulate OCTN1 transcription. To our knowledge, this is the first study to identify functional variants of the OCTN1 promoter.
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Affiliation(s)
- Hyo Jin Park
- Department of Pharmacology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul 158-710, Korea
| | - Ji Ha Choi
- Department of Pharmacology, Tissue Injury Defense Research Center, School of Medicine, Ewha Womans University, Seoul 158-710, Korea
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22
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Tullet JMA, Araiz C, Sanders MJ, Au C, Benedetto A, Papatheodorou I, Clark E, Schmeisser K, Jones D, Schuster EF, Thornton JM, Gems D. DAF-16/FoxO directly regulates an atypical AMP-activated protein kinase gamma isoform to mediate the effects of insulin/IGF-1 signaling on aging in Caenorhabditis elegans. PLoS Genet 2014; 10:e1004109. [PMID: 24516399 PMCID: PMC3916255 DOI: 10.1371/journal.pgen.1004109] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 12/02/2013] [Indexed: 11/18/2022] Open
Abstract
The DAF-16/FoxO transcription factor controls growth, metabolism and aging in Caenorhabditis elegans. The large number of genes that it regulates has been an obstacle to understanding its function. However, recent analysis of transcript and chromatin profiling implies that DAF-16 regulates relatively few genes directly, and that many of these encode other regulatory proteins. We have investigated the regulation by DAF-16 of genes encoding the AMP-activated protein kinase (AMPK), which has α, β and γ subunits. C. elegans has 5 genes encoding putative AMP-binding regulatory γ subunits, aakg-1-5. aakg-4 and aakg-5 are closely related, atypical isoforms, with orthologs throughout the Chromadorea class of nematodes. We report that ∼75% of total γ subunit mRNA encodes these 2 divergent isoforms, which lack consensus AMP-binding residues, suggesting AMP-independent kinase activity. DAF-16 directly activates expression of aakg-4, reduction of which suppresses longevity in daf-2 insulin/IGF-1 receptor mutants. This implies that an increase in the activity of AMPK containing the AAKG-4 γ subunit caused by direct activation by DAF-16 slows aging in daf-2 mutants. Knock down of aakg-4 expression caused a transient decrease in activation of expression in multiple DAF-16 target genes. This, taken together with previous evidence that AMPK promotes DAF-16 activity, implies the action of these two metabolic regulators in a positive feedback loop that accelerates the induction of DAF-16 target gene expression. The AMPK β subunit, aakb-1, also proved to be up-regulated by DAF-16, but had no effect on lifespan. These findings reveal key features of the architecture of the gene-regulatory network centered on DAF-16, and raise the possibility that activation of AMP-independent AMPK in nutritionally replete daf-2 mutant adults slows aging in C. elegans. Evidence of activation of AMPK subunits in mammals suggests that such FoxO-AMPK interactions may be evolutionarily conserved. Aging is an important problem for human health and is regulated by complex gene regulatory networks. In a simple nematode worm (Caenorhabditis elegans) mutation of the insulin/IGF-1 receptor daf-2 dramatically extends lifespan. This is due to the increased activity of DAF-16, a FoxO transcription factor, leading to altered expression of genes, many encoding other regulatory proteins. We have focused on one such protein, AMP-activated protein kinase (AMPK), that is important for regulating cellular homeostasis under conditions of low energy availability (e.g. starvation). We find that DAF-16 binds to the promoter of aakg-4 (a gene encoding an atypical γ subunit of AMPK) and increases its expression. Inhibition of aakg-4 leads to down-regulation of multiple DAF-16 target genes and shortens the life of daf-2 mutants. Taken together with a previous report showing that AMPK activates DAF-16, this suggests that AAKG-4 and DAF-16 are involved in a positive feedback loop which accelerates effects of DAF-16 on gene expression, and could contribute to longevity. This study defines a new part of the complex gene regulatory network in which DAF-16 acts to control aging. FoxO-AMPK interactions are present in higher animals, where they could potentially also influence aging.
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Affiliation(s)
- Jennifer M A Tullet
- Institute of Healthy Ageing, and Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Caroline Araiz
- Institute of Healthy Ageing, and Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Matthew J Sanders
- Institute of Healthy Ageing, and Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Catherine Au
- Institute of Healthy Ageing, and Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Alexandre Benedetto
- Institute of Healthy Ageing, and Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Irene Papatheodorou
- EMBL, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Emily Clark
- Institute of Healthy Ageing, and Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Kathrin Schmeisser
- Institute of Healthy Ageing, and Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Daniel Jones
- Institute of Healthy Ageing, and Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Eugene F Schuster
- Institute of Healthy Ageing, and Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Janet M Thornton
- EMBL, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - David Gems
- Institute of Healthy Ageing, and Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
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23
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Abstract
Stem cells exert precise regulation to maintain a balance of self-renewal and differentiation programs to sustain tissue homeostasis throughout the life of an organism. Recent evidence suggests that this regulation is modulated, in part, via metabolic changes and modifications of nutrient-sensing pathways such as mTOR and AMPK. It is becoming increasingly clear that stem cells inhibit oxidative phosphorylation in favor of aerobic glycolysis for energy production. Recent progress has detailed the molecular mechanisms of this metabolic phenotype and has offered insight into new metabolic pathways that may be involved in stem cell homeostasis.
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Affiliation(s)
- Joshua D Ochocki
- Abramson Family Cancer Research Institute, 2 Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104
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24
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Srivastava P, Mangal M, Agarwal SM. Understanding the transcriptional regulation of cervix cancer using microarray gene expression data and promoter sequence analysis of a curated gene set. Gene 2013; 535:233-8. [PMID: 24291025 DOI: 10.1016/j.gene.2013.11.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 11/12/2013] [Accepted: 11/15/2013] [Indexed: 02/08/2023]
Abstract
Cervical cancer, the malignant neoplasm of the cervix uteri is the second most common cancer among women worldwide and the top-most cancer in India. Several factors are responsible for causing cervical cancer, which alter the expression of oncogenic genes resulting in up or down-regulation of gene expression and inactivation of tumor-suppressor genes/gene products. Gene expression is regulated by interactions between transcription factors (TFs) and specific regulatory elements in the promoter regions of target genes. Thus, it is important to decipher and analyze TFs that bind to regulatory regions of diseased genes and regulate their expression. In the present study, computational methods involving the combination of gene expression data from microarray experiments and promoter sequence analysis of a curated gene set involved in the cervical cancer causation have been utilized for identifying potential regulatory elements. Consensus predictions of two approaches led to the identification of twelve TFs that might be crucial to the regulation of cervical cancer progression. Subsequently, TF enrichment and oncomine expression analysis suggested that the transcription factor family E2F played an important role for the regulation of genes involve in cervical carcinogenesis. Our results suggest that E2F possesses diagnostic/prognostic value and can act as a potential drug target in cervical cancer.
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Affiliation(s)
- Prashant Srivastava
- Integrative Genomics and Medicine, MRC Clinical Sciences, Imperial College, London, UK
| | - Manu Mangal
- Bioinformatics Division, Institute of Cytology and Preventive Oncology, Noida-201301, India
| | - Subhash Mohan Agarwal
- Bioinformatics Division, Institute of Cytology and Preventive Oncology, Noida-201301, India.
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25
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Xiao J, Zhou Y, Lai H, Lei S, Chi LH, Mo X. Transcription factor NF-Y is a functional regulator of the transcription of core clock gene Bmal1. J Biol Chem 2013; 288:31930-6. [PMID: 24030830 PMCID: PMC3814788 DOI: 10.1074/jbc.m113.507038] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 09/04/2013] [Indexed: 11/06/2022] Open
Abstract
The circadian clock enables organisms to adjust to daily environmental changes and synchronize multiple molecular, biochemical, physiological, and behavioral processes accordingly. In mammalian clock work, Bmal1 is the most important core clock gene, which works with another core clock gene Clock to drive the expression of other clock genes and clock-controlled genes. However, the regulation of Bmal1 has not been fully understood. This work was aimed at identifying the positive regulator(s) of Bmal1 transcription. A series of 5' deletion reporter constructs was generated, and binding site mutations of mouse Bmal1 promoter fragments were cloned into pGL3-basic and pGL3(R2.1)-basic plasmids and transfected into NIH 3T3 cells. Luciferase activity was either measured 48 h after transfection or recorded for 4 days after serum shock. DNA affinity precipitation assay was used to detect the transcription factors binding to Bmal1 promoter. Small interfering RNA against nuclear factor Y, subunit A (NF-YA) and dominant negative NF-YA were employed to study the role of NF-Y in Bmal1 transcription regulation. Deletion and mutation analyses identified two clusters of CCAAT/GC-boxes at the proximal region of Bmal1 promoter as the activating cis-elements. Bmal1 promoter activity was up-regulated by NF-Y and/or Sp1 and repressed by dominant negative NF-YA or siRNA against NF-YA. The activation of Bmal1 promoter activity by NF-Y and Sp1 was inhibited by Rev-Erbα. DNA affinity precipitation assay showed that NF-Y and Sp1 bound to the two CCAAT/GC clusters of Bmal1 promoter. These results indicate that NF-Y is a functional activator of Bmal1 transcription and it cooperates with Sp1 and Rev-Erbα to generate the daily cycle of Bmal1 expression.
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Affiliation(s)
- Jun Xiao
- From the Department of Gastrointestinal Surgery, Tumour Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China
| | - Yongchun Zhou
- the Department of Gastrointestinal Surgery, Guigang City People's Hospital, Guigang, 537100 Guangxi Autonomous Region, China
| | - Hao Lai
- From the Department of Gastrointestinal Surgery, Tumour Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China
| | - Shi Lei
- Chi Scientific, 85 Shashan Road, Jiangyin, Jiangsu 214434, China, and
| | - Lisa H. Chi
- CHI Scientific Inc., Maynard, Massachusetts 01754
| | - Xianwei Mo
- From the Department of Gastrointestinal Surgery, Tumour Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China
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26
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Sisci D, Maris P, Cesario MG, Anselmo W, Coroniti R, Trombino GE, Romeo F, Ferraro A, Lanzino M, Aquila S, Maggiolini M, Mauro L, Morelli C, Andò S. The estrogen receptor α is the key regulator of the bifunctional role of FoxO3a transcription factor in breast cancer motility and invasiveness. Cell Cycle 2013; 12:3405-20. [PMID: 24047697 DOI: 10.4161/cc.26421] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The role of the Forkhead box class O (FoxO)3a transcription factor in breast cancer migration and invasion is controversial. Here we show that FoxO3a overexpression decreases motility, invasiveness, and anchorage-independent growth in estrogen receptor α-positive (ERα+) cancer cells while eliciting opposite effects in ERα-silenced cells and in ERα-negative (ERα-) cell lines, demonstrating that the nuclear receptor represents a crucial switch in FoxO3a control of breast cancer cell aggressiveness. In ERα+ cells, FoxO3a-mediated events were paralleled by a significant induction of Caveolin-1 (Cav1), an essential constituent of caveolae negatively associated to tumor invasion and metastasis. Cav1 induction occurs at the transcriptional level through FoxO3a binding to a Forkhead responsive core sequence located at position -305/-299 of the Cav1 promoter. 17β-estradiol (E2) strongly emphasized FoxO3a effects on cell migration and invasion, while ERα and Cav1 silencing were able to reverse them, demonstrating that both proteins are pivotal mediators of these FoxO3a controlled processes. In vivo, an immunohistochemical analysis on tissue sections from patients with ERα+ or ERα- invasive breast cancers or in situ ductal carcinoma showed that nuclear FoxO3a inversely (ERα+) or directly (ERα-) correlated with the invasive phenotype of breast tumors. In conclusion, FoxO3a role in breast cancer motility and invasion depends on ERα status, disclosing a novel aspect of the well-established FoxO3a/ERα interplay. Therefore FoxO3a might become a pursuable target to be suitably exploited in combination therapies either in ERα+ or ERα- breast tumors.
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Affiliation(s)
- Diego Sisci
- Department of Pharmacy and Health and Nutritional Sciences; University of Calabria; Arcavacata di Rende; Cosenza, Italy
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27
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LKB1 downregulation may be independent of promoter methylation or FOXO3 expression in head and neck cancer. Transl Res 2013; 162:122-9. [PMID: 23810581 DOI: 10.1016/j.trsl.2013.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 05/30/2013] [Accepted: 06/03/2013] [Indexed: 01/29/2023]
Abstract
The serine/threonine kinase liver kinase B 1 (LKB1) is a multifunctional protein and has been associated with various cancer types. Although the tumor suppressor function of LKB1 is attributed mainly to its ability to phosphorylate directly different adenosine monophosphate-activated protein kinases, its regulation is still poorly understood. More recently, it has been shown that LKB1 expression can be regulated by forkhead box O transcription factors via cis-acting elements, which are found in the promoter region of the LKB1 gene. In this study, we investigated LKB1 messenger RNA expression levels in association with the promoter methylation of the gene and forkhead box O member 3 (FOXO3) messenger RNA expression in head and neck squamous cell carcinoma (HNSCC) tumor samples. Our results show that LKB1 expression is downregulated, especially in advanced-stage tumor samples, and this downregulation was not the result of promoter methylation or modulation by FOXO3 (P = 0.656). Despite observing a positive association between the LKB1 and FOXO3 expression levels in the tumors, this association was not statistically significant (P = 0.24). Our results indicate that downregulation of LKB1 is independent of FOXO3 and may be implicated in the progression of HNSCC.
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28
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Abstract
Forkhead box (FOX) proteins are multifaceted transcription factors that are responsible for fine-tuning the spatial and temporal expression of a broad range of genes both during development and in adult tissues. This function is engrained in their ability to integrate a multitude of cellular and environmental signals and to act with remarkable fidelity. Several key members of the FOXA, FOXC, FOXM, FOXO and FOXP subfamilies are strongly implicated in cancer, driving initiation, maintenance, progression and drug resistance. The functional complexities of FOX proteins are coming to light and have established these transcription factors as possible therapeutic targets and putative biomarkers for specific cancers.
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Affiliation(s)
- Eric W-F Lam
- Department of Surgery and Cancer, Imperial Centre for Translational and Experimental Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK.
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29
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Dual control of mitochondrial biogenesis by sirtuin 1 and sirtuin 3. Mitochondrion 2013; 13:755-61. [PMID: 23583953 DOI: 10.1016/j.mito.2013.04.002] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/25/2013] [Accepted: 04/04/2013] [Indexed: 12/31/2022]
Abstract
In this review, we discuss the dual control of mitochondrial biogenesis and energy metabolism by silent information regulator-1 and -3 (SIRT1 and SIRT3). SIRT1 activates the peroxisome proliferator activated receptor γ co-activator 1α (PGC-1α)-mediated transcription of nuclear and mitochondrial genes encoding for proteins promoting mitochondria proliferation, oxidative phosphorylation and energy production, whereas SIRT3 directly acts as an activator of proteins important for oxidative phosphorylation, tricarboxylic acid (TCA) cycle and fatty-acid oxidation and indirectly of PGC-1α and AMP-activated protein kinase (AMPK). The complex network involves different cellular compartments, transcriptional activation, post-translational modification and a plethora of secondary effectors. Overall, the mode of interaction between both sirtuin family members may be considered as a prominent case of molecular job-sharing.
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30
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Jang GH, Kim TH, Choe Y, Ham A, Choi JH. Functional characterization of genetic variations in the MDR3 promoter. Biochem Biophys Res Commun 2012; 430:1312-8. [PMID: 23261441 DOI: 10.1016/j.bbrc.2012.12.041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Accepted: 12/07/2012] [Indexed: 01/28/2023]
Abstract
Multidrug resistance 3 (MDR3) is present on the canalicular membrane of the hepatocyte and plays an important role in protecting the liver from bile acids. In this study, we characterized the transcriptional effects of four common haplotypes and four polymorphic variants in the promoter region of MDR3 that were identified in 126 DNA samples from Koreans. We measured the luciferase activities of the four MDR3 promoter haplotypes using in vitro reporter assays. Among them, two haplotypes showed a significant decrease in reporter activity compared to the reference. One of the mechanisms by which these haplotypes might decrease MDR3 transcriptional activity was determined: one of the polymorphisms that are present in haplotype 3, was associated with a significant reduction in the promoter activity of MDR3, and the transcription factor NF-Y was predicted to bind to the promoter in the region of g.-1584C>T. Electrophoretic mobility shift assays showed that the g.-1584C allele exhibited greater binding to NF-Y than did the g.-1584T allele. Through the measurement of promoter activity after the overexpression of NF-Y, we found that NF-Y can act as a transcriptional activator of MDR3. These data suggest that the reduced transcriptional activity of g.-1584C>T results from a reduction in the binding affinity of the activator NF-Y to the MDR3 promoter region. Our study suggests that two common haplotypes of MDR3 can regulate the transcriptional rate of MDR3 and that NF-Y may be one of the transcriptional factors involved in this regulation.
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Affiliation(s)
- Geun Hye Jang
- Department of Pharmacology, School of Medicine, Ewha Womans University, Seoul, Republic of Korea
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31
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FOXO3 is a glucocorticoid receptor target and regulates LKB1 and its own expression based on cellular AMP levels via a positive autoregulatory loop. PLoS One 2012; 7:e42166. [PMID: 22848740 PMCID: PMC3407083 DOI: 10.1371/journal.pone.0042166] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 07/02/2012] [Indexed: 01/04/2023] Open
Abstract
FOXO3 is a transcription factor involved in the regulation of multiple physiological processes including cell cycle arrest, apoptosis, oxidative stress-response and energy metabolism. Although much is known about its post-translational modification, the transcriptional regulation of FOXO3, as well as the cross-talk between transcription and post-translational events, is still poorly understood. In the present study, we show that FOXO3 is an immediate early glucocorticoid receptor (GR) target, whose transcription is even further enhanced by conditions that mimic metabolic stress. Induction of FOXO3 transcription by GR-binding steroids was reversed by concomitant treatment with the GR antagonist RU-486, but further enhanced by stimuli that activate the AMP-activated protein kinase (AMPK). Analysis of genomic DNA and chromatin immunoprecipitation, as well as luciferase reporter assays, revealed two functional glucocorticoid responsive elements within the FOXO3 promoter. Furthermore, we provide functional evidence for a phosphorylation switch that explains how glucocorticoids induce transcriptional activation of the gene but subsequently inactivate the corresponding protein by site-specific phosphorylation. Only when AMPK is stimulated, pre-existing FOXO3 becomes reverted toward an active form. Energy deprived conditions thus activate FOXO3 on two different levels, namely transcriptional and post-translational. In that way, FOXO3 acts as a metabolic stress sensor that coordinates expression of LKB1, the master upstream kinase involved in metabolic sensing, depending on the energy status of the cell. Additionally, we show that FOXO3 binds and activates its own promoter via a positive autoregulatory feedback loop. In conclusion, our data explain how catabolic glucocorticoid hormones and high intracellular AMP levels cooperate in inducing FOXO3 transcription and in activating the corresponding protein.
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