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Santos-Pereira M, Pereira SC, Rebelo I, Spadella MA, Oliveira PF, Alves MG. Decoding the Influence of Obesity on Prostate Cancer and Its Transgenerational Impact. Nutrients 2023; 15:4858. [PMID: 38068717 PMCID: PMC10707940 DOI: 10.3390/nu15234858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/12/2023] [Accepted: 11/16/2023] [Indexed: 12/18/2023] Open
Abstract
In recent decades, the escalating prevalence of metabolic disorders, notably obesity and being overweight, has emerged as a pressing concern in public health. Projections for the future indicate a continual upward trajectory in obesity rates, primarily attributable to unhealthy dietary patterns and sedentary lifestyles. The ramifications of obesity extend beyond its visible manifestations, intricately weaving a web of hormonal dysregulation, chronic inflammation, and oxidative stress. This nexus of factors holds particular significance in the context of carcinogenesis, notably in the case of prostate cancer (PCa), which is a pervasive malignancy and a leading cause of mortality among men. A compelling hypothesis arises from the perspective of transgenerational inheritance, wherein genetic and epigenetic imprints associated with obesity may wield influence over the development of PCa. This review proposes a comprehensive exploration of the nuanced mechanisms through which obesity disrupts prostate homeostasis and serves as a catalyst for PCa initiation. Additionally, it delves into the intriguing interplay between the transgenerational transmission of both obesity-related traits and the predisposition to PCa. Drawing insights from a spectrum of sources, ranging from in vitro and animal model research to human studies, this review endeavors to discuss the intricate connections between obesity and PCa. However, the landscape remains partially obscured as the current state of knowledge unveils only fragments of the complex mechanisms linking these phenomena. As research advances, unraveling the associated factors and underlying mechanisms promises to unveil novel avenues for understanding and potentially mitigating the nexus between obesity and the development of PCa.
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Affiliation(s)
- Mariana Santos-Pereira
- iBiMED-Institute of Biomedicine and Department of Medical Science, University of Aveiro, 3810-193 Aveiro, Portugal;
- Endocrine and Metabolic Research, Unit for Multidisciplinary Research in Biomedicine (UMIB), School of Medicine and Biomedical Sciences (ICBAS), University of Porto, 4050-313 Porto, Portugal;
- Laboratory for Integrative and Translational Research in Population Health (ITR), University of Porto, 4099-002 Porto, Portugal
| | - Sara C. Pereira
- Endocrine and Metabolic Research, Unit for Multidisciplinary Research in Biomedicine (UMIB), School of Medicine and Biomedical Sciences (ICBAS), University of Porto, 4050-313 Porto, Portugal;
- Laboratory for Integrative and Translational Research in Population Health (ITR), University of Porto, 4099-002 Porto, Portugal
- LAQV-REQUIMTE and Department of Chemistry, Campus Universitario de Santiago, University of Aveiro, 3810-193 Aveiro, Portugal;
- Department of Pathology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
| | - Irene Rebelo
- UCIBIO-REQUIMTE, Laboratory of Biochemistry, Department of Biologic Sciences, Pharmaceutical Faculty, University of Porto, 4050-313 Porto, Portugal;
| | - Maria A. Spadella
- Human Embryology Laboratory, Marília Medical School, Marília 17519-030, SP, Brazil;
| | - Pedro F. Oliveira
- LAQV-REQUIMTE and Department of Chemistry, Campus Universitario de Santiago, University of Aveiro, 3810-193 Aveiro, Portugal;
| | - Marco G. Alves
- iBiMED-Institute of Biomedicine and Department of Medical Science, University of Aveiro, 3810-193 Aveiro, Portugal;
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2
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Yang R, Han Y, Guan X, Hong Y, Meng J, Ding S, Long Q, Yi W. Regulation and clinical potential of telomerase reverse transcriptase (TERT/hTERT) in breast cancer. Cell Commun Signal 2023; 21:218. [PMID: 37612721 PMCID: PMC10463831 DOI: 10.1186/s12964-023-01244-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 07/23/2023] [Indexed: 08/25/2023] Open
Abstract
Telomerase reverse transcriptase (TERT/hTERT) serves as the pivotal catalytic subunit of telomerase, a crucial enzyme responsible for telomere maintenance and human genome stability. The high activation of hTERT, observed in over 90% of tumors, plays a significant role in tumor initiation and progression. An in-depth exploration of hTERT activation mechanisms in cancer holds promise for advancing our understanding of the disease and developing more effective treatment strategies. In breast cancer, the expression of hTERT is regulated by epigenetic, transcriptional, post-translational modification mechanisms and DNA variation. Besides its canonical function in telomere maintenance, hTERT exerts non-canonical roles that contribute to disease progression through telomerase-independent mechanisms. This comprehensive review summarizes the regulatory mechanisms governing hTERT in breast cancer and elucidates the functional implications of its activation. Given the overexpression of hTERT in most breast cancer cells, the detection of hTERT and its associated molecules are potential for enhancing early screening and prognostic evaluation of breast cancer. Although still in its early stages, therapeutic approaches targeting hTERT and its regulatory molecules show promise as viable strategies for breast cancer treatment. These methods are also discussed in this paper. Video Abstract.
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Affiliation(s)
- Ruozhu Yang
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Yi Han
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Xinyu Guan
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Yue Hong
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Jiahao Meng
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China
| | - Shirong Ding
- Department of Oncology, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
| | - Qian Long
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
| | - Wenjun Yi
- Department of General Surgery, the Second Xiangya Hospital of Central South University, 139 Middle Renmin Road, Changsha, 410011, China.
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3
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Buonaiuto R, Napolitano F, Parola S, De Placido P, Forestieri V, Pecoraro G, Servetto A, Formisano L, Formisano P, Giuliano M, Arpino G, De Placido S, De Angelis C. Insight on the Role of Leptin: A Bridge from Obesity to Breast Cancer. Biomolecules 2022; 12:biom12101394. [PMID: 36291602 PMCID: PMC9599120 DOI: 10.3390/biom12101394] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/21/2022] [Accepted: 09/25/2022] [Indexed: 11/26/2022] Open
Abstract
Leptin is a peptide hormone, mainly known for its role as a mediator of adipose tissue endocrine functions, such as appetite control and energy homeostasis. In addition, leptin signaling is involved in several physiological processes as modulation of innate and adaptive immune responses and regulation of sex hormone levels. When adipose tissue expands, an imbalance of adipokines secretion may occur and increasing leptin levels contribute to promoting a chronic inflammatory state, which is largely acknowledged as a hallmark of cancer. Indeed, upon binding its receptor (LEPR), leptin activates several oncogenic pathways, such as JAK/STAT, MAPK, and PI3K/AKT, and seems to affect cancer immune response by inducing a proinflammatory immune polarization and eventually enhancing T-cell exhaustion. In particular, obesity-associated hyperleptinemia has been related to breast cancer risk development, although the underlying mechanism is yet to be completely clarified and needs to be deemed in light of multiple variables, such as menopausal state and immune response. The aim of this review is to provide an overview of the potential role of leptin as a bridge between obesity and breast cancer and to establish the physio-pathological basis of the linkage between these major health concerns in order to identify appropriate and novel therapeutic strategies to adopt in daily clinical practice.
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Affiliation(s)
- Roberto Buonaiuto
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
| | - Fabiana Napolitano
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
| | - Sara Parola
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
| | - Pietro De Placido
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
| | - Valeria Forestieri
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
| | - Giovanna Pecoraro
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
| | - Alberto Servetto
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
| | - Luigi Formisano
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
| | - Pietro Formisano
- Department of Translational Medicine, University of Naples Federico II, 80131 Naples, Italy
| | - Mario Giuliano
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
| | - Grazia Arpino
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
| | - Sabino De Placido
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
| | - Carmine De Angelis
- Department of Clinical Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy
- Correspondence:
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Harris BHL, Macaulay VM, Harris DA, Klenerman P, Karpe F, Lord SR, Harris AL, Buffa FM. Obesity: a perfect storm for carcinogenesis. Cancer Metastasis Rev 2022; 41:491-515. [PMID: 36038791 PMCID: PMC9470699 DOI: 10.1007/s10555-022-10046-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/08/2022] [Indexed: 12/14/2022]
Abstract
Obesity-related cancers account for 40% of the cancer cases observed in the USA and obesity is overtaking smoking as the most widespread modifiable risk factor for carcinogenesis. Here, we use the hallmarks of cancer framework to delineate how obesity might influence the carcinogenic hallmarks in somatic cells. We discuss the effects of obesity on (a) sustaining proliferative signaling; (b) evading growth suppressors; (c) resisting cell death; (d) enabling replicative immortality; (e) inducing angiogenesis; (f) activating invasion and metastasis; (g) reprogramming energy metabolism; and (h) avoiding immune destruction, together with its effects on genome instability and tumour-promoting inflammation. We present the current understanding and controversies in this evolving field, and highlight some areas in need of further cross-disciplinary focus. For instance, the relative importance of the many potentially causative obesity-related factors is unclear for each type of malignancy. Even within a single tumour type, it is currently unknown whether one obesity-related factor consistently plays a predominant role, or if this varies between patients or, even in a single patient with time. Clarifying how the hallmarks are affected by obesity may lead to novel prevention and treatment strategies for the increasingly obese population.
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Affiliation(s)
- Benjamin H L Harris
- Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK.
- St Anne's College, 56 Woodstock Rd, Oxford, OX2 6HS, UK.
| | - Valentine M Macaulay
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, OX3 9DU, UK
| | | | - Paul Klenerman
- Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, OX1 3SY, UK
| | - Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Department of Medicine, University of Oxford, Oxford, OX3 7LE, UK
| | - Simon R Lord
- Early Phase Clinical Trials Unit, Churchill Hospital, Oxford, OX3 7LE, UK
| | - Adrian L Harris
- Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK
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Moraes JA, Encarnação C, Franco VA, Xavier Botelho LG, Rodrigues GP, Ramos-Andrade I, Barja-Fidalgo C, Renovato-Martins M. Adipose Tissue-Derived Extracellular Vesicles and the Tumor Microenvironment: Revisiting the Hallmarks of Cancer. Cancers (Basel) 2021; 13:3328. [PMID: 34283044 PMCID: PMC8268128 DOI: 10.3390/cancers13133328] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/26/2021] [Accepted: 06/28/2021] [Indexed: 12/11/2022] Open
Abstract
Extracellular vesicles (EVs) are crucial elements that sustain the communication between tumor cells and their microenvironment, and have emerged as a widespread mechanism of tumor formation and metastasis. In obesity, the adipose tissue becomes hypertrophic and hyperplastic, triggering increased production of pro-inflammatory adipokines, such as tumor necrosis factor α, interleukin 6, interleukin 1, and leptin. Furthermore, obese adipose tissue undergoes dysregulation in the cargo content of the released EVs, resulting in an increased content of pro-inflammatory proteins, fatty acids, and oncogenic microRNAs. These alterations drive obesity-associated inflammatory responses both locally and systemically. After being ignored for a long time, adipose tissues have recently received considerable attention as a major player in tumor microenvironment-linked obesity and cancer. The role of adipose tissue in the establishment and progression of cancer is reinforced by its high plasticity and inflammatory content. Such a relationship may be established by direct contact between adipocytes and cancer cells within the microenvironment or systemically, via EV-mediated cell-to-cell communication. Here, we highlight cues evidencing the influence of adipose tissue-derived EVs on the hallmarks of cancer, which are critical for tumor malignancy.
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Affiliation(s)
- João Alfredo Moraes
- Redox Biology Laboratory, Programa de Pesquisa em Farmacologia e Inflamação, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil;
| | - Carol Encarnação
- Laboratory of Inflammation and Metabolism, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, 24210-201 Niterói, Brazil; (C.E.); (V.A.F.); (L.G.X.B.); (G.P.R.)
| | - Victor Aguiar Franco
- Laboratory of Inflammation and Metabolism, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, 24210-201 Niterói, Brazil; (C.E.); (V.A.F.); (L.G.X.B.); (G.P.R.)
| | - Luiz Gabriel Xavier Botelho
- Laboratory of Inflammation and Metabolism, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, 24210-201 Niterói, Brazil; (C.E.); (V.A.F.); (L.G.X.B.); (G.P.R.)
| | - Gabriella Pacheco Rodrigues
- Laboratory of Inflammation and Metabolism, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, 24210-201 Niterói, Brazil; (C.E.); (V.A.F.); (L.G.X.B.); (G.P.R.)
| | - Isadora Ramos-Andrade
- Laboratory of Cellular and Molecular Pharmacology, Departamento de Biologia Celular, IBRAG, Universidade do Estado do Rio de Janeiro, 20550-170 Rio de Janeiro, Brazil; (I.R.-A.); (C.B.-F.)
| | - Christina Barja-Fidalgo
- Laboratory of Cellular and Molecular Pharmacology, Departamento de Biologia Celular, IBRAG, Universidade do Estado do Rio de Janeiro, 20550-170 Rio de Janeiro, Brazil; (I.R.-A.); (C.B.-F.)
| | - Mariana Renovato-Martins
- Laboratory of Inflammation and Metabolism, Departamento de Biologia Celular e Molecular, Instituto de Biologia, Universidade Federal Fluminense, 24210-201 Niterói, Brazil; (C.E.); (V.A.F.); (L.G.X.B.); (G.P.R.)
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6
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Tao L, Zhang W, Zhang Y, Zhang M, Zhang Y, Niu X, Zhao Q, Liu Z, Li Y, Diao A. Caffeine promotes the expression of telomerase reverse transcriptase to regulate cellular senescence and aging. Food Funct 2021; 12:2914-2924. [PMID: 33720241 DOI: 10.1039/d0fo03246h] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Telomere shortening is one of the main causes of cellular senescence. Caffeine is a natural stimulant most commonly found in coffee and tea. In this study, caffeine was found to promote the expression of telomerase reverse transcriptase (TERT) at both mRNA and protein levels, and consequently extended the telomere length and prevented cellular senescence. Knockdown of TERT eliminated the effect of caffeine on telomere elongation. Moreover, animal studies indicated that caffeine promoted the expression of TERT and extended the telomere length in the thymus and spleen of mice treated with caffeine for a long period of eight months. In addition, caffeine restored the decline of organ index and improved the histological structural change of the thymus, spleen and liver of mice due to aging. These results suggest that caffeine promotes the expression of TERT to delay cellular senescence and aging, which help to understand the mechanism for the beneficial effects of caffeine containing foods on health.
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Affiliation(s)
- Li Tao
- School of Biotechnology, Tianjin University of Science and Technology, Key Lab of Industrial Fermentation Microbiology of the Ministry of Education, State Key Laboratory of Food Nutrition and Safety, Tianjin 300457, China.
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7
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Engin AB, Engin A. The effect of environmental Bisphenol A exposure on breast cancer associated with obesity. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2021; 81:103544. [PMID: 33161112 DOI: 10.1016/j.etap.2020.103544] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/30/2020] [Accepted: 11/01/2020] [Indexed: 06/11/2023]
Abstract
Bisphenol A (BPA) is a widely used endocrine disrupter. Its environmental exposure is a causative factor of cell aging via decreasing telomerase activity, thus leading to shortening of telomere length. Epidemiological studies confirm positive associations between BPA exposure and the incidence of obesity and type 2 diabetes (T2DM). Increased urinary BPA levels in obese females are both significantly correlated with shorter relative telomere length and T2DM. BPA is a critically effective endocrine disrupter leading to poor prognosis via the obesity-inflammation-aromatase axis in breast cancer. Environmental BPA exposure contributes to the progression of both estrogen dependent and triple negative breast cancers. BPA is a positive regulator of human telomerase reverse transcriptase (hTERT) and it increases the expression of hTERT mRNA in breast cancer cells. BPA exposure can lead to tamoxifen resistance. Among patients treated with chemotherapy, those with persistent high telomerase activity due to BPA are at higher risk of death.
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Affiliation(s)
- Ayse Basak Engin
- Gazi University, Faculty of Pharmacy, Department of Toxicology, Ankara, Turkey.
| | - Atilla Engin
- Gazi University, Faculty of Medicine, Department of General Surgery, Ankara, Turkey
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Sánchez-Jiménez F, Pérez-Pérez A, de la Cruz-Merino L, Sánchez-Margalet V. Obesity and Breast Cancer: Role of Leptin. Front Oncol 2019; 9:596. [PMID: 31380268 PMCID: PMC6657346 DOI: 10.3389/fonc.2019.00596] [Citation(s) in RCA: 141] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 06/17/2019] [Indexed: 01/08/2023] Open
Abstract
Obesity-related breast cancer is an important threat that affects especially post-menopausal women. The link between obesity and breast cancer seems to be relying on the microenvironment generated at adipose tissue level, which includes inflammatory cytokines. In addition, its association with systemic endocrine changes, including hyperinsulinemia, increased estrogens levels, and hyperleptinemia may be key factors for tumor development. These factors may promote tumor initiation, tumor primary growth, tissue invasion, and metastatic progression. Although the relationship between obesity and breast cancer is already established, the different pathophysiological mechanisms involved are not clear. Obesity-related insulin resistance is a well-known risk factor for breast cancer development in post-menopausal women. However, the role of inflammation and other adipokines, especially leptin, is less studied. Leptin, like insulin, appears to be a growth factor for breast cancer cells. There exists a link between leptin and metabolism of estrogens and between leptin and other factors in a more complex network. As a result, obesity-associated hyperleptinemia has been suggested as an important mediator in the pathophysiology of breast cancer. On the other hand, recent data on the paradoxical effect of obesity on cancer immunotherapy efficacy has brought some controversy, since the proinflammatory effect of leptin may help the effect of immune checkpoint inhibitors. Therefore, a better knowledge of the molecular mechanisms that mediate leptin action may be helpful to understand the underlying processes which link obesity to breast cancer in post-menopausal women, as well as the possible role of leptin in the response to immunotherapy in obese patients.
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Affiliation(s)
- Flora Sánchez-Jiménez
- Department of Medical Biochemistry and Molecular Biology, and Immunology, School of Medicine, Virgen Macarena University Hospital, University of Seville, Seville, Spain
| | - Antonio Pérez-Pérez
- Department of Medical Biochemistry and Molecular Biology, and Immunology, School of Medicine, Virgen Macarena University Hospital, University of Seville, Seville, Spain
| | - Luis de la Cruz-Merino
- Department of Clinical Oncology, Virgen Macarena University Hospital, University of Seville, Seville, Spain
| | - Víctor Sánchez-Margalet
- Department of Medical Biochemistry and Molecular Biology, and Immunology, School of Medicine, Virgen Macarena University Hospital, University of Seville, Seville, Spain
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Crean-Tate KK, Reizes O. Leptin Regulation of Cancer Stem Cells in Breast and Gynecologic Cancer. Endocrinology 2018; 159:3069-3080. [PMID: 29955847 PMCID: PMC6669812 DOI: 10.1210/en.2018-00379] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 06/19/2018] [Indexed: 12/18/2022]
Abstract
It is well established that obesity increases the incidence and worsens the prognosis of women's cancer. For breast cancer, women with obesity exhibit more than a twofold increase in the odds of being diagnosed with cancer, with a greater risk of advanced stage at diagnosis, and ≤40% greater risk of recurrence and death than their normal-weight counterparts. These findings are similar in gynecologic cancers, where women who are obese with a body mass index (BMI) >40 kg/m2 have up to six times greater risk of developing endometrial cancer and a 9.2% increase in mortality with every 10% increase in BMI. Likewise, patients with obesity exhibit a twofold higher risk of premenopausal ovarian cancer, and patients who are obese with advanced stage ovarian cancer have shown a shorter time to recurrence and poorer overall survival. Obesity is accompanied by changes in expression of adipose factors that act on local tissues and systemically. Once obesity was recognized as a factor in cancer incidence and progression, the adipose cytokine (adipokine) leptin became the focus of intense investigation as a putative link, with nearly 3000 publications on the topic. Leptin has been shown to increase cell proliferation, inhibit apoptosis, promote angiogenesis, and increase therapeutic resistance. These characteristics are associated with a subset of cells in both liquid and solid tumors known as cancer stem cells (CSCs), or tumor initiating cells. We will review the literature discussing leptin's role in breast and gynecologic cancer, focusing on its role in CSCs, and consider goals for targeting future therapy in this arena to disrupt tumor initiation and progression in women's cancer.
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Affiliation(s)
- Katie K Crean-Tate
- Department of Obstetrics and Gynecology, Women’s Health Institute, Cleveland Clinic, Cleveland, Ohio
| | - Ofer Reizes
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio
- Case Comprehensive Cancer Center, Cleveland, Ohio
- Correspondence: Ofer Reizes, PhD, Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, NC10, Cleveland, Ohio 44195. E-mail:
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González-González A, Mediavilla MD, Sánchez-Barceló EJ. Melatonin: A Molecule for Reducing Breast Cancer Risk. Molecules 2018; 23:E336. [PMID: 29415446 PMCID: PMC6017232 DOI: 10.3390/molecules23020336] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 01/31/2018] [Accepted: 01/31/2018] [Indexed: 01/10/2023] Open
Abstract
The objective of this article is to review the basis supporting the usefulness of melatonin as an adjuvant therapy for breast cancer (BC) prevention in several groups of individuals at high risk for this disease. Melatonin, as a result of its antiestrogenic and antioxidant properties, as well as its ability to improve the efficacy and reduce the side effects of conventional antiestrogens, could safely be associated with the antiestrogenic drugs presently in use. In individuals at risk of BC due to night shift work, the light-induced inhibition of melatonin secretion, with the consequent loss of its antiestrogenic effects, would be countered by administering this neurohormone. BC risk from exposure to metalloestrogens, such as cadmium, could be treated with melatonin supplements to individuals at risk of BC due to exposure to this xenoestrogen. The BC risk related to obesity may be reduced by melatonin which decrease body fat mass, inhibits the enhanced aromatase expression in obese women, increases adiponectin secretion, counteracts the oncogenic effects of elevated concentrations of leptin; and decreases blood glucose levels and insulin resistance. Despite compelling experimental evidence of melatonin's oncostatic actions being susceptible to lowering BC risk, there is still a paucity of clinical trials focused on this subject.
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Affiliation(s)
- Alicia González-González
- Department of Physiology and Pharmacology, School of Medicina, University of Cantabria, 39011 Santander, Spain.
| | - María Dolores Mediavilla
- Department of Physiology and Pharmacology, School of Medicina, University of Cantabria, 39011 Santander, Spain.
| | - Emilio J Sánchez-Barceló
- Department of Physiology and Pharmacology, School of Medicina, University of Cantabria, 39011 Santander, Spain.
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Cases MG, Frugé AD, De Los Santos JF, Locher JL, Cantor AB, Smith KP, Glover TA, Cohen HJ, Daniel M, Morrow CD, Moellering DR, Demark-Wahnefried W. Detailed methods of two home-based vegetable gardening intervention trials to improve diet, physical activity, and quality of life in two different populations of cancer survivors. Contemp Clin Trials 2016; 50:201-12. [PMID: 27565830 PMCID: PMC5055381 DOI: 10.1016/j.cct.2016.08.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 08/10/2016] [Accepted: 08/22/2016] [Indexed: 01/15/2023]
Abstract
BACKGROUND Cancer survivors suffer from long-term adverse effects that reduce health-related quality of life (QOL) and physical functioning, creating an urgent need to develop effective, durable, and disseminable interventions. Harvest for Health, a home-based vegetable gardening intervention, holds promise for these domains. METHODS This report describes the methods and recruitment experiences from two randomized controlled feasibility trials that employ a waitlist-controlled design. Delivered in partnership with Cooperative Extension Master Gardeners, this intervention provides one-on-one mentorship of cancer survivors in planning and maintaining three seasonal vegetable gardens over 12months. The primary aim is to determine intervention feasibility and acceptability; secondary aims are to explore effects on objective and subjective measures of diet, physical activity and function, and QOL and examine participant factors associated with potential effects. One trial is conducted exclusively among 82 female breast cancer survivors residing in the Birmingham, AL metropolitan area (BBCS); another broadly throughout Alabama among 46 older cancer survivors aged >60 (ASCS). RESULTS Response rates were 32.6% (BBCS) and 52.3% (ASCS). Both trials exceeded 80% of their accrual target. Leading reasons for ineligibility were removal of >10 lymph nodes (lymphedema risk factor), lack of physician approval, and unwillingness to be randomized to the waitlist. CONCLUSION To date, recruitment and implementation of Harvest for Health appears feasible. DISCUSSION Although both studies encountered recruitment challenges, lessons learned can inform future larger-scale studies. Vegetable gardening interventions are of interest to cancer survivors and may provide opportunities to gain life skills leading to improvements in overall health and QOL.
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Affiliation(s)
- Mallory G Cases
- Department of Health Behavior, School of Public Health, University of Alabama at Birmingham, 1675 University Boulevard, Webb Building 346, Birmingham, AL 35294, United States.
| | - Andrew D Frugé
- Department of Nutrition Sciences, School of Health Professions, University of Alabama at Birmingham, 1675 University Boulevard, Webb Building 346, Birmingham, AL 35294, United States
| | - Jennifer F De Los Santos
- Department of Radiation Oncology, School of Medicine, University of Alabama at Birmingham, The Kirklin Clinic at Acton Road, 2145 Bonner Way, Birmingham, AL 35243, United States
| | - Julie L Locher
- Department of Health Care Organization and Policy, School of Public Health, University of Alabama at Birmingham, 1530 3rd Avenue South, CH19-Room 218F, Birmingham, AL 35294, United States
| | - Alan B Cantor
- Department of Biostatistics, School of Public Health, University of Alabama at Birmingham, 1665 University Boulevard, Ryals Public Health Building, Room 327, Birmingham, AL 35294, United States
| | - Kerry P Smith
- Alabama Cooperative Extension System, Alabama A&M University and Auburn University, 101 Funchess Hall, Auburn University, AL 36849, United States
| | - Tony A Glover
- Alabama Cooperative Extension System, Alabama A&M University and Auburn University, 101 Funchess Hall, Auburn University, AL 36849, United States
| | - Harvey J Cohen
- Center for the Study of Aging, Duke University, Room 3502 Blue Zone, Duke University Medical Center Box 3003, Durham, NC 27710, United States
| | - Michael Daniel
- Department of Biology, College of Arts & Sciences, University of Alabama at Birmingham, 1675 University Boulevard, Webb Building 346, Birmingham, AL 35294, United States
| | - Casey D Morrow
- Department of Cell, Developmental, and Integrative Biology, School of Medicine, University of Alabama at Birmingham, 1720 2nd Avenue South, THT 926, Birmingham, AL 35294, United States
| | - Douglas R Moellering
- Department of Nutrition Sciences, School of Health Professions, University of Alabama at Birmingham, 1675 University Boulevard, Webb Building 346, Birmingham, AL 35294, United States; UAB Diabetes Research Center, Bioanalytical Redox Biology Core, University of Alabama at Birmingham, 1670 University Boulevard, VH G004, Birmingham, AL 35294, United States
| | - Wendy Demark-Wahnefried
- Department of Nutrition Sciences, School of Health Professions, University of Alabama at Birmingham, 1675 University Boulevard, Webb Building 346, Birmingham, AL 35294, United States
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Transcription Regulation of the Human Telomerase Reverse Transcriptase (hTERT) Gene. Genes (Basel) 2016; 7:genes7080050. [PMID: 27548225 PMCID: PMC4999838 DOI: 10.3390/genes7080050] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/23/2016] [Accepted: 08/01/2016] [Indexed: 12/11/2022] Open
Abstract
Embryonic stem cells and induced pluripotent stem cells have the ability to maintain their telomere length via expression of an enzymatic complex called telomerase. Similarly, more than 85%–90% of cancer cells are found to upregulate the expression of telomerase, conferring them with the potential to proliferate indefinitely. Telomerase Reverse Transcriptase (TERT), the catalytic subunit of telomerase holoenzyme, is the rate-limiting factor in reconstituting telomerase activity in vivo. To date, the expression and function of the human Telomerase Reverse Transcriptase (hTERT) gene are known to be regulated at various molecular levels (including genetic, mRNA, protein and subcellular localization) by a number of diverse factors. Among these means of regulation, transcription modulation is the most important, as evident in its tight regulation in cancer cell survival as well as pluripotent stem cell maintenance and differentiation. Here, we discuss how hTERT gene transcription is regulated, mainly focusing on the contribution of trans-acting factors such as transcription factors and epigenetic modifiers, as well as genetic alterations in hTERT proximal promoter.
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13
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Leptin-Induced JAK/STAT Signaling and Cancer Growth. Vaccines (Basel) 2016; 4:vaccines4030026. [PMID: 27472371 PMCID: PMC5041020 DOI: 10.3390/vaccines4030026] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 07/11/2016] [Accepted: 07/12/2016] [Indexed: 02/08/2023] Open
Abstract
Growth factor and cytokine signaling can influence the development of several cancer types. One of the key players in the development of cancer is the Janus kinas (JAK) signal transducer of activators of transcription (STAT) signaling pathway. The majority of growth factors and cytokine interactions with their membrane-bound receptors trigger JAK-STAT activation. The influential relationship between obesity and cancer is a fact. However, there is a complex sequence of events contributing to the regulation of this mechanism to promote tumor growth, yet to be fully elucidated. The JAK-STAT pathway is influenced by obesity-associated changes that have been shown to impact cancer growth and progression. This intricate process is highly regulated by a vast array of adipokines and cytokines that exert their pleiotropic effects on cancer cells to enhance metastasis to distant target sites. Leptin is a cytokine, or more precise, an adipokine secreted mainly by adipose tissue that requires JAK-STAT activation to exert its biological functions. Leptin is the central regulator of energy balance and appetite. Leptin binding to its receptor OB-R in turn activates JAK-STAT, which induces proliferation, angiogenesis, and anti-apoptotic events in normal cells and malignant cells expressing the receptor. Leptin also induces crosstalk with Notch and IL-1 (NILCO), which involves other angiogenic factors promoting tumor growth. Therefore, the existence of multiple novel classes of therapeutics that target the JAK/STAT pathway has significant clinical implications. Then, the identification of the signaling networks and factors that regulate the obesity-cancer link to which potential pharmacologic interventions can be implemented to inhibit tumor growth and metastasis. In this review, we will discuss the specific relationship between leptin-JAK-STAT signaling and cancer.
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Oztas E, Kara H, Kara ZP, Aydogan MU, Uras C, Ozhan G. Association Between Human Telomerase Reverse Transcriptase Gene Variations and Risk of Developing Breast Cancer. Genet Test Mol Biomarkers 2016; 20:459-64. [PMID: 27336831 DOI: 10.1089/gtmb.2015.0339] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Despite a reduction in the number of deaths from cancers made possible by the development of early detection tests, improvements in treatment, changes in the age distribution of the population, and changes of personal behaviors as a result of awareness, breast cancer remains a major health problem worldwide. Breast cancer is the most common cancer and second leading cause of cancer death in women. Several genetic and environmental factors are known to be involved in breast cancer pathogenesis, but its exact etiology is complicated and is not clearly identified. The structure and integrity of telomeres are pivotal for genome stability, and telomere length is maintained by the expression of the telomerase enzyme. The human telomerase reverse transcriptase (hTERT) gene is a principal functional subunit of the telomerase. Several recent studies have provided evidence that hTERT gene variants may have an important role in cancer development. METHODS Three hTERT variants (rs2736100, rs2736098, and rs2853669) were genotyped for 107 breast cancer patients and 110 healthy controls to determine their effect on breast cancer susceptibility. RESULTS It was observed that hTERT rs2736098 was associated with breast cancer risk (odds ratio [OR] = 1.88; p = 0.034), while rs2736100 and rs2853669 did not significantly differ between the groups. CONCLUSIONS These findings are the first description of hTERT allele distributions in the Turkish population and may contribute to our understanding of breast cancer development. Nevertheless, further large-scale population studies are needed to understand the role of the hTERT polymorphisms and haplotypes in the development of breast cancer.
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Affiliation(s)
- Ezgi Oztas
- 1 Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Istanbul University , Istanbul, Turkey
| | - Halil Kara
- 2 Department of General Surgery, Faculty of Medicine, Acibadem University , Istanbul, Turkey
| | - Zeliha Pala Kara
- 3 Department of Pharmacology, Faculty of Pharmacy, Istanbul University , Istanbul, Turkey
| | - Manolya Uras Aydogan
- 4 Department of Physiology, Cerrahpasa Medical Faculty, Istanbul University , Istanbul, Turkey
| | - Cihan Uras
- 2 Department of General Surgery, Faculty of Medicine, Acibadem University , Istanbul, Turkey
| | - Gul Ozhan
- 1 Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Istanbul University , Istanbul, Turkey
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15
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Lipsey CC, Harbuzariu A, Daley-Brown D, Gonzalez-Perez RR. Oncogenic role of leptin and Notch interleukin-1 leptin crosstalk outcome in cancer. World J Methodol 2016; 6:43-55. [PMID: 27019796 PMCID: PMC4804251 DOI: 10.5662/wjm.v6.i1.43] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 11/11/2015] [Accepted: 03/09/2016] [Indexed: 02/06/2023] Open
Abstract
Obesity is a global pandemic characterized by high levels of body fat (adiposity) and derived-cytokines (i.e., leptin). Research shows that adiposity and leptin provide insight on the link between obesity and cancer progression. Leptin’s main function is to regulate energy balance. However, obese individuals routinely develop leptin resistance, which is the consequence of the breakdown in the signaling mechanism controlling satiety resulting in the accumulation of leptin. Therefore, leptin levels are often chronically elevated in human obesity. Elevated leptin levels are related to higher incidence, increased progression and poor prognosis of several human cancers. In addition to adipose tissue, cancer cells can also secrete leptin and overexpress leptin receptors. Leptin is known to act as a mitogen, inflammatory and pro-angiogenic factor that induces cancer cell proliferation and tumor angiogenesis. Moreover, leptin signaling induces cancer stem cells, which are involved in cancer recurrence and drug resistance. A novel and complex signaling crosstalk between leptin, Notch and interleukin-1 (IL-1) [Notch, IL-1 and leptin crosstalk outcome (NILCO)] seems to be an important driver of leptin-induced oncogenic actions. Leptin and NILCO signaling mediate the activation of cancer stem cells that can affect drug resistance. Thus, leptin and NILCO signaling are key links between obesity and cancer progression. This review presents updated data suggesting that adiposity affects cancer incidence, progression, and response to treatment. Here we show data supporting the oncogenic role of leptin in breast, endometrial, and pancreatic cancers.
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Shouman S, Wagih M, Kamel M. Leptin influences estrogen metabolism and increases DNA adduct formation in breast cancer cells. Cancer Biol Med 2016; 13:505-513. [PMID: 28154783 PMCID: PMC5250609 DOI: 10.20892/j.issn.2095-3941.2016.0079] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Objective: The elevated incidence of obesity has been paralleled with higher risks of breast cancer. High adiposity increases leptin secretion from adipose tissue, which in turn increases cancer cell proliferation. The interplay between leptin and estrogen is one of the mechanisms through which leptin influences breast carcinogenesis. An unbalanced estrogen metabolism increases the formations of catechol estrogen quinones, DNA adducts, and cancer mutations. This study aims to investigate the effect of leptin on some estrogen metabolic enzymes and DNA adduction in breast cancer cells. Methods: High performance liquid chromatography (HPLC) was performed to analyze the DNA adducts 4-OHE1[E2]-1-N3 adenine and 4-OHE1[E2]-1-N7 guanine. Reporter gene assay, real time reverse transcription polymerase chain reaction (real time RT-PCR), and Western blot were used to assess the expression of estrogen metabolizing genes and enzymes: Cytochrome P-450 1B1 (CYP1B1), Nicotinamide adenine dinucleotide phosphate-quinone oxidoreductase1 (NQO1), and Catechol-O-methyl transferase (COMT). Results: Leptin significantly increased the DNA adducts 4-OHE1[E2]-1-N3 adenine and 4-OHE1[E2]-1-N7 guanine. Furthermore, leptin significantly upregulated CYP1B1 promoter activity and protein expression. The luciferase promoter activities of NQO1 and mRNA levels were significantly reduced. Moreover, leptin greatly reduced the reporter activities of the COMT-P1 and COMT-P2 promoters and diminished the protein expression of COMT. Conclusions: Leptin increases DNA adduct levels in breast cancer cells partly by affecting key genes and enzymes involved in estrogen metabolism. Thus, increased focus should be directed toward leptin and its effects on the estrogen metabolic pathway as an effective approach against breast cancer.
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Affiliation(s)
- Samia Shouman
- Department of Cancer Biology, Unit of Pharmacology, National Cancer Institute, Cairo University, Cairo 11796, Egypt
| | - Mohamed Wagih
- Department of Pathology, Faculty of Medicine, Beni-Suef University, Benisuef 62511, Egypt
| | - Marwa Kamel
- Department of Cancer Biology, Unit of Pharmacology, National Cancer Institute, Cairo University, Cairo 11796, Egypt
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17
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Yang Y, Cheng J, Ren H, Zhao H, Gong W, Shan C. Tumor FOXP3 represses the expression of long noncoding RNA 7SL. Biochem Biophys Res Commun 2015; 472:432-6. [PMID: 26718402 DOI: 10.1016/j.bbrc.2015.12.082] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 12/19/2015] [Indexed: 01/21/2023]
Abstract
The long noncoding RNA 7SL was over-expressed in tumor cells to promote cell growth through repressing translation of P53. However, the regulatory mechanism of 7SL remains to be defined. FOXP3 was identified as a suppressor in several tumors in addition to be a marker of regulatory T cells. In this study, we detected that over-expression of FOXP3 repressed the transcription of 7SL RNA and contributed to inhibiting tumor growth. Knock down of FOXP3 in MCF-10A normal mammary breast cells up-regulated the transcription of 7SL RNA. Chromatin Immuno-precipitation (ChIP) analysis showed that FOXP3 directly bound to the Forkhead/HNF-3 domain DNA binding sites (-789 to -795) relative to the transcription start site. Meanwhile, Luciferase analysis showed that FOXP3 repressed the full-length 7SL promoter activity, but this suppressive effect was reversed after mutation of the FOXP3 binding site. Further studies showed that FOXP3 promoted the expression of P53 at translational levels through repressing 7SL RNA. In conclusion, this study suggests that 7SL RNA is a direct target of FOXP3 and may be involved in the formation of FOXP3/P53 feedback loop.
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Affiliation(s)
- Yanhui Yang
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, 300070 Tianjin, China
| | - Jingli Cheng
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, 300070 Tianjin, China
| | - Huizhu Ren
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, 300070 Tianjin, China
| | - Hui Zhao
- Tianjin Key Laboratory of Food Biotechnology, School of Biotechnology and Food Science, Tianjin University of Commerce, 300134, China
| | - Wei Gong
- Institute of Radiation Medicine of Chinese Academy of Medical Science and Peking Union Medical College, Tianjin, 300192, China
| | - Chunyan Shan
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, 300070 Tianjin, China.
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18
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Miranda-Furtado CL, Ramos FKP, Kogure GS, Santana-Lemos BA, Ferriani RA, Calado RT, Dos Reis RM. A Nonrandomized Trial of Progressive Resistance Training Intervention in Women With Polycystic Ovary Syndrome and Its Implications in Telomere Content. Reprod Sci 2015; 23:644-54. [PMID: 26586671 DOI: 10.1177/1933719115611753] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Physical activity is known to relieve the metabolic complications of polycystic ovary syndrome (PCOS), and exercise is also associated with telomere biology. We investigated the changes induced by progressive resistance training (PRT) in telomere content and metabolic disorder in women with PCOS and controls. PARTICIPANTS AND METHODS Forty-five women with PCOS and 52 healthy women aged 18 to 37 years were submitted to PRT. A linear periodization of PRT was prepared based on a trend of decreasing volume and intensity throughout the training period. The volunteers performed PRT 3 times a week for 4 months. The participants' physical characteristics and hormonal concentrations were measured before and after PRT, as telomere content that was measured using quantitative real-time polymerase chain reaction. RESULTS Briefly, Progressive resistance training reduced waist circumference, body fat percentage, plasma testosterone and sex hormone-binding globulin concentrations, glycemia, and free androgen index. Fasting insulin and insulin resistance index were greater in women with PCOS. Androstenedione and homocysteine increased after PRT. There were no differences in telomere content between controls (0.96 ± 0.3 before vs 0.85 ± 0.21 after) and women with PCOS (0.94 ± 0.33 before vs 0.88 ± 0.39 after). Adjusted analysis showed telomere shortening after PRT in all women (0.95 ± 0.31 before vs 0.86 ± 0.31 after; P = .03). In women with PCOS, increased homocysteine levels were related to telomere reduction and increased androstenedione was positively correlated with telomere content after PRT. CONCLUSIONS Progressive resistance training had positive effects on the hormonal and physical characteristics of women with PCOS and controls, but telomere content was reduced and homocysteine level increased in all participants.
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Affiliation(s)
| | - Fabiene K Picchi Ramos
- Department of Gynecology and Obstetrics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Gislaine Satyko Kogure
- Department of Gynecology and Obstetrics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Barbara A Santana-Lemos
- Department of Internal Medicine, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Rui Alberto Ferriani
- Department of Gynecology and Obstetrics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Rodrigo Tocantins Calado
- Department of Internal Medicine, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Rosana Maria Dos Reis
- Department of Gynecology and Obstetrics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
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19
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Jiang N, Sun R, Sun Q. Leptin signaling molecular actions and drug target in hepatocellular carcinoma. DRUG DESIGN DEVELOPMENT AND THERAPY 2014; 8:2295-302. [PMID: 25484575 PMCID: PMC4238752 DOI: 10.2147/dddt.s69004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Previous reports indicate that over 13 different tumors, including hepatocellular carcinoma (HCC), are related to obesity. Obesity-associated inflammatory, metabolic, and endocrine mediators, as well as the functioning of the gut microbiota, are suspected to contribute to tumorigenesis. In obese people, proinflammatory cytokines/chemokines including tumor necrosis factor-alpha, interleukin (IL)-1 and IL-6, insulin and insulin-like growth factors, adipokines, plasminogen activator inhibitor-1, adiponectin, and leptin are found to play crucial roles in the initiation and development of cancer. The cytokines induced by leptin in adipose tissue or tumor cells have been intensely studied. Leptin-induced signaling pathways are critical for biological functions such as adiposity, energy balance, endocrine function, immune reaction, and angiogenesis as well as oncogenesis. Leptin is an activator of cell proliferation and anti-apoptosis in several cell types, and an inducer of cancer stem cells; its critical roles in tumorigenesis are based on its oncogenic, mitogenic, proinflammatory, and pro-angiogenic actions. This review provides an update of the pathological effects of leptin signaling with special emphasis on potential molecular mechanisms and therapeutic targeting, which could potentially be used in future clinical settings. In addition, leptin-induced angiogenic ability and molecular mechanisms in HCC are discussed. The stringent binding affinity of leptin and its receptor Ob-R, as well as the highly upregulated expression of both leptin and Ob-R in cancer cells compared to normal cells, makes leptin an ideal drug target for the prevention and treatment of HCC, especially in obese patients.
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Affiliation(s)
- Nan Jiang
- Shandong University School of Medicine, Jinan, Shandong Province, People's Republic of China
| | - Rongtong Sun
- Weihai Municipal Hospital, Weihai, Shandong Province, People's Republic of China
| | - Qing Sun
- Department of Pathology, QianFoShan Hospital Affiliated to Shandong University, Jinan, Shandong Province, People's Republic of China
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20
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Kasiappan R, Sun Y, Lungchukiet P, Quarni W, Zhang X, Bai W. Vitamin D suppresses leptin stimulation of cancer growth through microRNA. Cancer Res 2014; 74:6194-204. [PMID: 25252917 DOI: 10.1158/0008-5472.can-14-1702] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Obesity is a pandemic and major risk factor for cancers. The reduction of obesity would have been an effective strategy for cancer prevention, but the reality is that worldwide obesity has kept increasing for decades, remaining a major avoidable cancer risk secondary only to smoke. The present studies suggest that vitamin D may be an effective agent to reduce obesity-associated cancer risks in women. Molecular analyses showed that leptin increased human telomerase reverse transcriptase (hTERT) mRNA expression and cell growth through estrogen receptor-α (ERα) activation in ovarian cancer cells, which was suppressed by 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3]. The suppression was compromised when miR-498 induction by the hormone was depleted with microRNA (miRNA) sponges. In mice, high-fat diet (HFD) stimulation of ovarian tumor growth was remarkably suppressed by 1,25(OH)2D3 analogue EB1089, which was also compromised by miR-498 sponges. EB1089 did not alter HFD-induced increase in serum leptin levels but increased miR-498 and decreased the diet-induced hTERT expression in tumors. Quantitative RT-PCR analyses revealed an inverse correlation between hTERT mRNA and miR-498 in response to 1,25(OH)2D3 in estrogen-sensitive ovarian, endometrial, and breast cancers. The studies suggest that miR-498-mediated hTERT downregulation is a key event mediating the anti-leptin activity of 1,25(OH)2D3 in estrogen-sensitive tumors in women.
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Affiliation(s)
- Ravi Kasiappan
- Department of Pathology and Cell Biology, University of South Florida College of Medicine, Tampa, Florida
| | - Yuefeng Sun
- Department of Pathology and Cell Biology, University of South Florida College of Medicine, Tampa, Florida
| | - Panida Lungchukiet
- Department of Pathology and Cell Biology, University of South Florida College of Medicine, Tampa, Florida
| | - Waise Quarni
- Department of Pathology and Cell Biology, University of South Florida College of Medicine, Tampa, Florida
| | - Xiaohong Zhang
- Department of Pathology and Cell Biology, University of South Florida College of Medicine, Tampa, Florida. Department of Oncological Sciences, University of South Florida College of Medicine, Tampa, Florida. Program of Cancer Biology and Evolution, H. Lee Moffitt Cancer Center, Tampa, Florida
| | - Wenlong Bai
- Department of Pathology and Cell Biology, University of South Florida College of Medicine, Tampa, Florida. Department of Oncological Sciences, University of South Florida College of Medicine, Tampa, Florida. Program of Cancer Biology and Evolution, H. Lee Moffitt Cancer Center, Tampa, Florida.
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21
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Zhou W, Tian Y, Gong H, Guo S, Luo C. Oncogenic role and therapeutic target of leptin signaling in colorectal cancer. Expert Opin Ther Targets 2014; 18:961-71. [PMID: 24946986 DOI: 10.1517/14728222.2014.926889] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Obesity is characterized by high secretion of several cytokines from adipose tissue and is a recognized risk factor for many cancers. Among these cytokines, leptin mainly produced by adipose tissue and cancer cells is the most studied adipokine. Leptin is an activator of cell proliferation, an antiapoptotic molecule and inducer of cancer stem cells in many cell types, and its critical roles in obesity-related tumorigenesis are based on its oncogenic, mitogenic, pro-inflammatory and pro-angiogenic actions. AREAS COVERED These leptin-induced signals and action are critical for their biological effects on energy balance, adiposity, endocrine systems, immunity, angiogenesis as well as oncogenesis. This review focuses on the up-to-date knowledge on the oncogenic role of leptin signaling, clinical significance and specific drug target development in colorectal cancer (CRC). Additionally, leptin-induced angiogenic ability and molecular mechanisms in CRC cells are discussed. EXPERT OPINION Stringent binding affinity of leptin/Ob-R and overexpression of leptin/Ob-R and their targets in cancer cells make it a unique drug target for prevention and treatment of CRC, particularly in obesity colorectal patients.
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Affiliation(s)
- Weiqiang Zhou
- Shenyang Medical College, Key Laboratory of Environmental Pollution and Microecology of Liaoning Province , No.146 North Huanghe St, Huanggu Dis, Shenyang City, Liaoning Pro 110034 , PR China
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22
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Role of adipokines and cytokines in obesity-associated breast cancer: therapeutic targets. Cytokine Growth Factor Rev 2013; 24:503-13. [PMID: 24210902 DOI: 10.1016/j.cytogfr.2013.10.001] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 10/10/2013] [Accepted: 10/11/2013] [Indexed: 02/06/2023]
Abstract
Obesity is the cause of a large proportion of breast cancer incidences and mortality in post-menopausal women. In obese people, elevated levels of various growth factors such as insulin and insulin-like growth factors (IGFs) are found. Elevated insulin level leads to increased secretion of estrogen by binding to the circulating sex hormone binding globulin (SHBG). The increased estrogen-mediated downstream signaling favors breast carcinogenesis. Obesity leads to altered expression profiles of various adipokines and cytokines including leptin, adiponectin, IL-6, TNF-α and IL-1β. The increased levels of leptin and decreased adiponectin secretion are directly associated with breast cancer development. Increased levels of pro-inflammatory cytokines within the tumor microenvironment promote tumor development. Efficacy of available breast cancer drugs against obesity-associated breast cancer is yet to be confirmed. In this review, we will discuss different adipokine- and cytokine-mediated molecular signaling pathways involved in obesity-associated breast cancer, available therapeutic strategies and potential therapeutic targets for obesity-associated breast cancer.
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23
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Holysz H, Lipinska N, Paszel-Jaworska A, Rubis B. Telomerase as a useful target in cancer fighting-the breast cancer case. Tumour Biol 2013; 34:1371-80. [PMID: 23558965 PMCID: PMC3661921 DOI: 10.1007/s13277-013-0757-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 03/20/2013] [Indexed: 12/17/2022] Open
Abstract
Telomerase was initially considered as a relevant factor distinguishing cancer from normal cells. During detailed studies, it appeared that its expression and activity is not only limited to cancer cells however, but in this particular cells, the telomerase is much more abundant. Thus, it has become a very promising target for an anticancer therapy. It was revealed in many studies that regulation of telomerase is a multifactorial process in mammalian cells, involving regulation of expression of telomerase subunits coding genes, post-translational protein–protein interactions, and protein phosphorylation. Numerous proto-oncogenes and tumor suppressor genes are engaged in this mechanism, and the complexity of telomerase control is studied in the context of tumor development as well as aging. Additionally, since numerous studies reveal a correlation between short telomeres and increased genome instability or cell mortality, the telomerase control appears to be one of the crucial factors to study in order to improve the cancer diagnostics and therapy or prevention. Interestingly, almost 100 % of adenocarcinoma, including breast cancer cells, expresses telomerase which makes it a good target for telomerase-related therapy. Additionally, telomerase is also supposed to be associated with drug resistance. Thus, targeting the enzyme might result in attenuation of this phenomenon. Moreover, since stem cells existence was reported, it must be considered whether targeting telomerase can bring some serious side effects and result in stem cells viability or their regenerative potential decrease. Thus, we review some molecular mechanisms engaged in therapy based on targeting telomerase in breast cancer cells.
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Affiliation(s)
- Hanna Holysz
- Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, ul. Przybyszewskiego 49, 60-355, Poznan, Poland
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Ernst M, Putoczki TL. Stat3: Linking inflammation to (gastrointestinal) tumourigenesis. Clin Exp Pharmacol Physiol 2012; 39:711-8. [DOI: 10.1111/j.1440-1681.2011.05659.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Matthias Ernst
- Ludwig Institute for Cancer Research; Melbourne Parkville Branch; Melbourne; Victoria; Australia
| | - Tracy L Putoczki
- Ludwig Institute for Cancer Research; Melbourne Parkville Branch; Melbourne; Victoria; Australia
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25
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Ryu DW, Lee CH. Circulating Tumor Cells and Extracellular Nucleic Acids in Breast Cancer. KOSIN MEDICAL JOURNAL 2012. [DOI: 10.7180/kmj.2012.27.1.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Circulating tumor cells (CTCs) are defined as tumor cells circulating in the peripheral blood of patients, shed from either the primary tumor or from its metastases. The detection of circulating tumor cells (CTCs) in the peripheral blood of breast cancer patients may account for the different steps in the biologic progression of the disease. The detection of microscopic disease in patients with breast cancer is imperative to prognosis and can predict the efficacy of targeted treatments. In general, there are two main methods for their detection. These are based on cytometric and nucleic acid manipulation. Both methods generally require an enrichment step to increase sensitivity of the assay. This step is based on either detection of specific surface markers using immuno-selection and/or on morphological features, such as cell size or density. We review the methods of detecting CTCs, their prognostic implications, and opportunities to exploit the properties of CTCs to develop personalized therapy.
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Tzanetakou IP, Katsilambros NL, Benetos A, Mikhailidis DP, Perrea DN. "Is obesity linked to aging?": adipose tissue and the role of telomeres. Ageing Res Rev 2012; 11:220-9. [PMID: 22186032 DOI: 10.1016/j.arr.2011.12.003] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 11/22/2011] [Accepted: 12/06/2011] [Indexed: 12/28/2022]
Abstract
Obesity is a condition in which excess or abnormal fat accumulation may present with adverse effects on health and decreased life expectancy. Increased body weight and adipose tissue accumulation amplifies the risk of developing various age-related diseases, such as cardiovascular disease, type 2 diabetes mellitus, musculoskeletal disorders, respiratory diseases and certain types of cancer. This imbalance in body composition and body weight is now recognized as a state of increased oxidative stress and inflammation for the organism. Increasing oxidative stress and inflammation affect telomeres. Telomeres are specialized DNA-protein structures found at the ends of eukaryotic chromosomes and serve as markers of biological aging rate. They also play a critical role in maintaining genomic integrity and are involved in age-related metabolic dysfunction. Erosion of telomeres is hazardous to healthy cells, as it is a known mechanism of premature cellular senescence and loss of longevity. The association of telomeres and oxidative stress is evident in cultured somatic cells in vitro, where oxidative stress enhances the process of erosion with each cycle of replication. Shorter telomeres have been associated with increasing body mass index, increased adiposity, and more recently with increasing waist to hip ratio and visceral excess fat accumulation. Furthermore, many of the metabolic imbalances of obesity (e.g. glycemic, lipidemic, etc.) give rise to organ dysfunction in a way that resembles the accelerated aging process. This article is a non-systematic review of the evidence linking obesity and accelerated aging processes as they are regulated by telomeres.
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Affiliation(s)
- Irene P Tzanetakou
- Laboratory for Experimental Surgery and Surgical Research "N. S. Christeas", University of Athens Medical School, Greece.
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Abstract
Telomeres are stretches of repeated DNA sequences located at the ends of chromosomes that are necessary to prevent loss of gene-coding DNA regions during replication. Telomerase – the enzyme responsible for immortalising cancer cells through the addition of telomeric repeats – is active in ~90% of human cancers. Telomerase activity is inhibited by various phytochemicals such as isoprenoids, genistein, curcumin, epigallocatechin-3-gallate, resveratrol and others. Human TERT (telomerase reverse transcriptase – the rate-limiting component of telomerase), heat shock protein 90, Akt, p70 S6 kinase (S6K) and mammalian target of rapamycin (mTOR) form a physical and functional complex with one another. The inclusion of Akt, mTOR and S6K in the TERT complex is compelling evidence to support mTOR-mediated control of telomerase activity. This review will define the role of mTOR, the master regulator of protein translation, in telomerase regulation and provide additional insights into the numerous ways in which telomerase activity is hindered by phytochemicals.
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Regulation of the human catalytic subunit of telomerase (hTERT). Gene 2012; 498:135-46. [PMID: 22381618 DOI: 10.1016/j.gene.2012.01.095] [Citation(s) in RCA: 199] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 01/29/2012] [Accepted: 01/30/2012] [Indexed: 12/12/2022]
Abstract
Over the past decade, there has been much interest in the regulation of telomerase, the enzyme responsible for maintaining the integrity of chromosomal ends, and its crucial role in cellular immortalization, tumorigenesis, and the progression of cancer. Telomerase activity is characterized by the expression of the telomerase reverse transcriptase (TERT) gene, suggesting that TERT serves as the major limiting agent for telomerase activity. Recent discoveries have led to characterization of various interactants that aid in the regulation of human TERT (hTERT), including numerous transcription factors; further supporting the pivotal role that transcription plays in both the expression and repression of telomerase. Several studies have suggested that epigenetic modulation of the hTERT core promoter region may provide an additional level of regulation. Although these studies have provided essential information on the regulation of hTERT, there has been ambiguity of the role of methylation within the core promoter region and the subsequent binding of various activating and repressive agents. As a result, we found it necessary to consolidate and summarize these recent developments and elucidate these discrepancies. In this review, we focus on the co-regulation of hTERT via transcriptional regulation, the presence or absence of various activators and repressors, as well as the epigenetic pathways of DNA methylation and histone modifications.
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Guo S, Liu M, Wang G, Torroella-Kouri M, Gonzalez-Perez RR. Oncogenic role and therapeutic target of leptin signaling in breast cancer and cancer stem cells. Biochim Biophys Acta Rev Cancer 2012; 1825:207-22. [PMID: 22289780 DOI: 10.1016/j.bbcan.2012.01.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Revised: 01/12/2012] [Accepted: 01/15/2012] [Indexed: 12/17/2022]
Abstract
Significant correlations between obesity and incidence of various cancers have been reported. Obesity, considered a mild inflammatory process, is characterized by a high level of secretion of several cytokines from adipose tissue. These molecules have disparate effects, which could be relevant to cancer development. Among the inflammatory molecules, leptin, mainly produced by adipose tissue and overexpressed with its receptor (Ob-R) in cancer cells is the most studied adipokine. Mutations of leptin or Ob-R genes associated with obesity or cancer are rarely found. However, leptin is an anti-apoptotic molecule in many cell types, and its central roles in obesity-related cancers are based on its pro-angiogenic, pro-inflammatory and mitogenic actions. Notably, these leptin actions are commonly reinforced through entangled crosstalk with multiple oncogenes, cytokines and growth factors. Leptin-induced signals comprise several pathways commonly triggered by many cytokines (i.e., canonical: JAK2/STAT; MAPK/ERK1/2 and PI-3K/AKT1 and, non-canonical signaling pathways: PKC, JNK and p38 MAP kinase). Each of these leptin-induced signals is essential to its biological effects on food intake, energy balance, adiposity, immune and endocrine systems, as well as oncogenesis. This review is mainly focused on the current knowledge of the oncogenic role of leptin in breast cancer. Additionally, leptin pro-angiogenic molecular mechanisms and its potential role in breast cancer stem cells will be reviewed. Strict biunivocal binding-affinity and activation of leptin/Ob-R complex makes it a unique molecular target for prevention and treatment of breast cancer, particularly in obesity contexts.
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Affiliation(s)
- Shanchun Guo
- Microbiology, Biochemistry & Immunology, Morehouse School of Medicine, Atlanta, GA 30310, USA
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30
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Oncogenic role and therapeutic target of leptin signaling in breast cancer and cancer stem cells. BIOCHIMICA ET BIOPHYSICA ACTA 2012. [PMID: 22289780 DOI: 10.1016/j.bbcan.2012.01.002.oncogenic] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Significant correlations between obesity and incidence of various cancers have been reported. Obesity, considered a mild inflammatory process, is characterized by a high level of secretion of several cytokines from adipose tissue. These molecules have disparate effects, which could be relevant to cancer development. Among the inflammatory molecules, leptin, mainly produced by adipose tissue and overexpressed with its receptor (Ob-R) in cancer cells is the most studied adipokine. Mutations of leptin or Ob-R genes associated with obesity or cancer are rarely found. However, leptin is an anti-apoptotic molecule in many cell types, and its central roles in obesity-related cancers are based on its pro-angiogenic, pro-inflammatory and mitogenic actions. Notably, these leptin actions are commonly reinforced through entangled crosstalk with multiple oncogenes, cytokines and growth factors. Leptin-induced signals comprise several pathways commonly triggered by many cytokines (i.e., canonical: JAK2/STAT; MAPK/ERK1/2 and PI-3K/AKT1 and, non-canonical signaling pathways: PKC, JNK and p38 MAP kinase). Each of these leptin-induced signals is essential to its biological effects on food intake, energy balance, adiposity, immune and endocrine systems, as well as oncogenesis. This review is mainly focused on the current knowledge of the oncogenic role of leptin in breast cancer. Additionally, leptin pro-angiogenic molecular mechanisms and its potential role in breast cancer stem cells will be reviewed. Strict biunivocal binding-affinity and activation of leptin/Ob-R complex makes it a unique molecular target for prevention and treatment of breast cancer, particularly in obesity contexts.
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Perks CM, Holly JMP. Hormonal mechanisms underlying the relationship between obesity and breast cancer. Endocrinol Metab Clin North Am 2011; 40:485-507, vii. [PMID: 21889716 DOI: 10.1016/j.ecl.2011.05.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Given the worldwide epidemic of obesity, it is inevitably an increasingly common comorbidity for women who develop breast cancer; therefore, it is critical to understand its impact on this disease. This review focuses on the influence of obesity on breast cancer development and progression and describes the hormonal factors that may underlie the observations, with particular emphasis on the roles of estrogen, insulin/insulin-like growth factor axis, and adipokines.
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Affiliation(s)
- Claire M Perks
- School of Clinical Sciences, University of Bristol, Southmead Hospital, Bristol, UK.
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Gladych M, Wojtyla A, Rubis B. Human telomerase expression regulation. Biochem Cell Biol 2011; 89:359-76. [DOI: 10.1139/o11-037] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Since telomerase has been recognized as a relevant factor distinguishing cancer cells from normal cells, it has become a very promising target for anti-cancer therapy. A correlation between short telomere length and increased mortality was revealed in many studies. The telomerase expression/activity appears to be one of the most crucial factors to study to improve cancer therapy and prevention. However, this multisubunit enzymatic complex can be regulated at various levels. Thus, several strategies have been proposed to control telomerase in cancer cells such as anti-sense technology against TR and TERT, ribozymes against TERT, anti-estrogens, progesterone, vitamin D, retinoic acid, quadruplex stabilizers, telomere and telomerase targeting agents, modulation of interaction with other proteins involved in the regulation of telomerase and telomeres, etc. However, the transcription control of key telomerase subunits seems to play the crucial role in whole complexes activity and cancer cells immortality. Thus, the research of telomerase regulation can bring significant insight into the knowledge concerning stem cells metabolism but also ageing. This review summarizes the current state of knowledge of numerous telomerase regulation mechanisms at the transcription level in human that might become attractive anti-cancer therapy targets.
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Affiliation(s)
- Marta Gladych
- Poznan University of Medical Sciences, Department of Clinical Chemistry and Molecular Diagnostics, Przybyszewskiego 49 St., 60-355 Poznan, Poland
| | - Aneta Wojtyla
- Poznan University of Medical Sciences, Department of Clinical Chemistry and Molecular Diagnostics, Przybyszewskiego 49 St., 60-355 Poznan, Poland
| | - Blazej Rubis
- Poznan University of Medical Sciences, Department of Clinical Chemistry and Molecular Diagnostics, Przybyszewskiego 49 St., 60-355 Poznan, Poland
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Rahmati-Yamchi M, Zarghami N, Rahbani M, Montazeri A. Plasma Leptin, hTERT Gene Expression, and Anthropometric Measures in Obese and Non-Obese Women with Breast Cancer. BREAST CANCER-BASIC AND CLINICAL RESEARCH 2011; 5:27-35. [PMID: 21494399 PMCID: PMC3076011 DOI: 10.4137/bcbcr.s6734] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Introduction: Expression of human telomerase reverse transcriptase (hTERT) occurs in most cancers but its relation with obesity is unclear. This study explores the association between leptin levels and anthropometric indices with hTERT mRNA levels in breast cancer patients of different obesity grades. Materials and methods: In this case-control study, 65 breast cancer patients participated. Expression of tissues hTERT mRNA was carried out by real-time reverse transcription polymerase chain reaction. Leptin concentrations were measured by enzyme-linked immunoassay. Results: Twelve patients (18.46%) were hTERT negative and 53(81.54%) were positive. hTERT mRNA levels were associated with BMI but not with waist circumference (WC) (r = 0.219, P = 0.22) and waist to hip ratio (WHR) (r = 0.212, P = 0.237). Leptin level and hTERT mRNA levels (r = 0.484, P = 0.008) were correlated as well as BMI and hTERT expression. Conclusions: This study has shown a correlation between leptin levels and hTERT expression. These findings may clarify the role of leptin in breast carcinogenesis, and hence obesity could be responsible for increased incidences in breast cancer as well as its progression via enhanced production of leptin.
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Affiliation(s)
- Mohammad Rahmati-Yamchi
- Department of Clinical Biochemistry, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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Role of obesity-associated dysfunctional adipose tissue in cancer: a molecular nutrition approach. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1807:664-78. [PMID: 21111705 DOI: 10.1016/j.bbabio.2010.11.004] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 11/09/2010] [Accepted: 11/09/2010] [Indexed: 02/08/2023]
Abstract
Obesity is a complex disease caused by the interaction of a myriad of genetic, dietary, lifestyle and environmental factors, which favors a chronic positive energy balance, leading to increased body fat mass. There is emerging evidence of a strong association between obesity and an increased risk of cancer. However, the mechanisms linking both diseases are not fully understood. Here, we analyze the current knowledge about the potential contribution that expanding adipose tissue in obesity could make to the development of cancer via dysregulated secretion of pro-inflammatory cytokines, chemokines and adipokines such as TNF-α, IL-6, leptin, adiponectin, visfatin and PAI-1. Dietary factors play an important role in the risk of suffering obesity and cancer. The identification of bioactive dietary factors or substances that affect some of the components of energy balance to prevent/reduce weight gain as well as cancer is a promising avenue of research. This article reviews the beneficial effects of some bioactive food molecules (n-3 PUFA, CLA, resveratrol and lipoic acid) in energy metabolism and cancer, focusing on the molecular mechanisms involved, which may provide new therapeutic targets in obesity and cancer.
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Stefanou N, Papanikolaou V, Furukawa Y, Nakamura Y, Tsezou A. Leptin as a critical regulator of hepatocellular carcinoma development through modulation of human telomerase reverse transcriptase. BMC Cancer 2010; 10:442. [PMID: 20723213 PMCID: PMC2931493 DOI: 10.1186/1471-2407-10-442] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 08/19/2010] [Indexed: 12/15/2022] Open
Abstract
Background Numerous epidemiological studies have documented that obesity is associated with hepatocellular carcinoma (HCC). The aim of this study was to investigate the biological actions regulated by leptin, the obesity biomarker molecule, and its receptors in HCC and the correlation between leptin and human telomerase reverse transcriptase (hTERT), a known mediator of cellular immortalization. Methods We investigated the relationship between leptin, leptin receptors and hTERT mRNA expression in HCC and healthy liver tissue samples. In HepG2 cells, chromatin immunoprecipitation assay was used to study signal transducer and activator of transcription-3 (STAT3) and myc/mad/max transcription factors downstream of leptin which could be responsible for hTERT regulation. Flow cytometry was used for evaluation of cell cycle modifications and MMP1, 9 and 13 expression after treatment of HepG2 cells with leptin. Blocking of leptin's expression was achieved using siRNA against leptin and transfection with liposomes. Results We showed, for the first time, that leptin's expression is highly correlated with hTERT expression levels in HCC liver tissues. We also demonstrated in HepG2 cells that leptin-induced up-regulation of hTERT and TA was mediated through binding of STAT3 and Myc/Max/Mad network proteins on hTERT promoter. We also found that leptin could affect hepatocellular carcinoma progression and invasion through its interaction with cytokines and matrix mettaloproteinases (MMPs) in the tumorigenic microenvironment. Furthermore, we showed that histone modification contributes to leptin's gene regulation in HCC. Conclusions We propose that leptin is a key regulator of the malignant properties of hepatocellular carcinoma cells through modulation of hTERT, a critical player of oncogenesis.
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Affiliation(s)
- Nikolaos Stefanou
- University of Thessaly, Medical School, Department of Biology, Larissa, Greece
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Liu L, Xie JW, Wang X, Xie YM. EGCG in combination with radiotherapy down-regulates hTERT expression in HepG2 cells. Shijie Huaren Xiaohua Zazhi 2010; 18:1873-1878. [DOI: 10.11569/wcjd.v18.i18.1873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the effect of (-)-epigallocatechin-3-gallate (EGCG) in combination with radiotherapy (different doses) on the expression of hTERT in HepG2 cells and to explore the possibility of using EGCG as a radiation sensitizer.
METHODS: To find an optimal EGCG dose used in subsequent experiments, the effect of different concentrations of EGCG on the proliferation and apoptosis of HepG2 cells was detected by MTT assay and fluorescence microscopy. After HepG2 cells were treated with EGCG (25 μmol/L) in combination with different doses of radiotherapy (2, 4 and 6 Gy, respectively), the expression of hTERT in HepG2 cells was detected by real-time fluorescent quantitative PCR.
RESULTS: EGCG could inhibit proliferation and induce apoptosis in HepG2 cells. Treatment of HepG2 cells with EGCG in combination with different doses of radiotherapy (2, 4 and 6 Gy, respectively) significantly down-regulated hTERT expression when compared with those treated with EGCG alone (0.477 ± 0.025 vs 0.973 ± 0.024, 1.110 ± 0.083 vs 1.382 ± 0.051, 1.174 ± 0.128 vs 1.452 ± 0.109; all P < 0.01 or 0.05), particularly prominent in cells undergoing radiotherapy at a dose of 2 GY.
CONCLUSION: EGCG can inhibit proliferation and induce apoptosis in HepG2 cells. EGCG in combination with different doses of radiotherapy can down-regulate hTERT expression in HepG2 cells and thus inhibit telomerase activity. EGCG may be a potential radiation sensitizer.
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