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Huna A, Massemin A, Makulyte G, Flaman JM, Martin N, Bernard D. Regulation of cell function and identity by cellular senescence. J Cell Biol 2024; 223:e202401112. [PMID: 38865089 PMCID: PMC11169915 DOI: 10.1083/jcb.202401112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/26/2024] [Accepted: 05/29/2024] [Indexed: 06/13/2024] Open
Abstract
During aging and in some contexts, like embryonic development, wound healing, and diseases such as cancer, senescent cells accumulate and play a key role in different pathophysiological functions. A long-held belief was that cellular senescence decreased normal cell functions, given the loss of proliferation of senescent cells. This view radically changed following the discovery of the senescence-associated secretory phenotype (SASP), factors released by senescent cells into their microenvironment. There is now accumulating evidence that cellular senescence also promotes gain-of-function effects by establishing, reinforcing, or changing cell identity, which can have a beneficial or deleterious impact on pathophysiology. These effects may involve both proliferation arrest and autocrine SASP production, although they largely remain to be defined. Here, we provide a historical overview of the first studies on senescence and an insight into emerging trends regarding the effects of senescence on cell identity.
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Affiliation(s)
- Anda Huna
- Equipe Labellisée la Ligue Contre le Cancer, Centre de Recherche en Cancérologie de Lyon, Inserm U1052, CNRS UMR 5286, Université de Lyon, Centre Léon Bérard, Lyon, France
| | - Amélie Massemin
- Equipe Labellisée la Ligue Contre le Cancer, Centre de Recherche en Cancérologie de Lyon, Inserm U1052, CNRS UMR 5286, Université de Lyon, Centre Léon Bérard, Lyon, France
| | - Gabriela Makulyte
- Equipe Labellisée la Ligue Contre le Cancer, Centre de Recherche en Cancérologie de Lyon, Inserm U1052, CNRS UMR 5286, Université de Lyon, Centre Léon Bérard, Lyon, France
| | - Jean-Michel Flaman
- Equipe Labellisée la Ligue Contre le Cancer, Centre de Recherche en Cancérologie de Lyon, Inserm U1052, CNRS UMR 5286, Université de Lyon, Centre Léon Bérard, Lyon, France
| | - Nadine Martin
- Equipe Labellisée la Ligue Contre le Cancer, Centre de Recherche en Cancérologie de Lyon, Inserm U1052, CNRS UMR 5286, Université de Lyon, Centre Léon Bérard, Lyon, France
| | - David Bernard
- Equipe Labellisée la Ligue Contre le Cancer, Centre de Recherche en Cancérologie de Lyon, Inserm U1052, CNRS UMR 5286, Université de Lyon, Centre Léon Bérard, Lyon, France
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Wang Z, Chen X, Qiu X, Chen Y, Wang T, Lv L, Guo X, Yang F, Tang M, Gu W, Luo Y. High-Fidelity Sensitive Tracing Circulating Tumor Cell Telomerase Activity. Anal Chem 2024; 96:5527-5536. [PMID: 38483815 DOI: 10.1021/acs.analchem.3c05749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
Dynamic tracing of intracellular telomerase activity plays a crucial role in cancer cell recognition and correspondingly in earlier cancer diagnosis and personalized precision therapy. However, due to the complexity of the required reaction system and insufficient loading of reaction components into cells, achieving a high-fidelity determination of telomerase activity is still a challenge. Herein, an Aptamer-Liposome mediated Telomerase activated poly-Molecular beacon Arborescent Nanoassembly(ALTMAN) approach was described for direct high-fidelity visualization of telomerase activity. Briefly, intracellular telomerase activates molecular beacons, causing their hairpin structures to unfold and produce fluorescent signals. Furthermore, multiple molecular beacons can self-assemble, forming arborescent nanostructures and leading to exponential amplification of fluorescent signals. Integrating the enzyme-free isothermal signal amplification successfully increased the sensitivity and reduced interference by leveraging the skillful design of the molecular beacon and the extension of the telomerase-activated TTAGGG repeat sequence. The proposed approach enabled ultrasensitive visualization of activated telomerase exclusively with a prominent detection limit of 2 cells·μL-1 and realized real-time imaging of telomerase activity in living cancer cells including blood samples from breast cancer patients and urine samples from bladder cancer patients. This approach opens an avenue for establishing a telomerase activity determination and in situ monitoring technique that can facilitate both telomerase fundamental biological studies and cancer diagnostics.
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Affiliation(s)
- Zining Wang
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, Chongqing University, Chongqing 400044, P.R. China
| | - Xiaohui Chen
- Department of Clinical Laboratory, Fuling Hospital, Chongqing University, Chongqing 408099, P.R. China
- NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing University, Chongqing 400044, P.R. China
| | - Xiaopei Qiu
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, Chongqing University, Chongqing 400044, P.R. China
| | - Yi Chen
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, Chongqing University, Chongqing 400044, P.R. China
| | - Tian Wang
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, Chongqing University, Chongqing 400044, P.R. China
| | - Linxi Lv
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, Chongqing University, Chongqing 400044, P.R. China
| | - Xinlin Guo
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, Chongqing University, Chongqing 400044, P.R. China
| | - Fei Yang
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, Chongqing University, Chongqing 400044, P.R. China
| | - Miao Tang
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, Chongqing University, Chongqing 400044, P.R. China
| | - Wei Gu
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, Chongqing University, Chongqing 400044, P.R. China
| | - Yang Luo
- Center of Smart Laboratory and Molecular Medicine, School of Medicine, Chongqing University, Chongqing 400044, P.R. China
- NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing University, Chongqing 400044, P.R. China
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Galati L, Chiantore MV, Marinaro M, Di Bonito P. Human Oncogenic Viruses: Characteristics and Prevention Strategies-Lessons Learned from Human Papillomaviruses. Viruses 2024; 16:416. [PMID: 38543781 PMCID: PMC10974567 DOI: 10.3390/v16030416] [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: 01/11/2024] [Revised: 03/05/2024] [Accepted: 03/06/2024] [Indexed: 05/23/2024] Open
Abstract
Approximately 12% of human cancers worldwide are associated with infectious agents, which are classified by the International Agency for Research on Cancer (IARC) as Group 1 within the agents that are carcinogenic to humans. Most of these agents are viruses. Group 1 oncogenic viruses include hepatitis C virus, hepatitis B virus (HBV), human T-cell lymphotropic virus type 1, Epstein-Barr virus, Kaposi sarcoma-associated herpesvirus, human immunodeficiency virus-1 and high-risk human papillomaviruses (HPVs). In addition, some human polyomaviruses are suspected of inducing cancer prevalently in hosts with impaired immune responses. Merkel cell polyomavirus has been associated with Merkel cell carcinoma and included by the IARC in Group 2A (i.e., probably carcinogenic to humans). Linking viruses to human cancers has allowed for the development of diagnostic, prophylactic and therapeutic measures. Vaccination significantly reduced tumours induced by two oncogenic viruses as follows: HBV and HPV. Herein, we focus on mucosal alpha HPVs, which are responsible for the highest number of cancer cases due to tumour viruses and against which effective prevention strategies have been developed to reduce the global burden of HPV-related cancers.
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Affiliation(s)
- Luisa Galati
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, 20139 Milan, Italy;
| | - Maria Vincenza Chiantore
- Department of Infectious Diseases, Viral Hepatitis and Oncovirus and Retrovirus Diseases (EVOR) Unit, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy;
| | - Mariarosaria Marinaro
- Department of Infectious Diseases, Microorganisms and Host Response: Research and Technological Innovation (MICROS) Unit, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy;
| | - Paola Di Bonito
- Department of Infectious Diseases, Viral Hepatitis and Oncovirus and Retrovirus Diseases (EVOR) Unit, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy;
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El Zarif T, Machaalani M, Nawfal R, Nassar AH, Xie W, Choueiri TK, Pomerantz M. TERT Promoter Mutations Frequency Across Race, Sex, and Cancer Type. Oncologist 2024; 29:8-14. [PMID: 37462445 PMCID: PMC10769781 DOI: 10.1093/oncolo/oyad208] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 06/23/2023] [Indexed: 01/07/2024] Open
Abstract
BACKGROUND Telomerase reverse transcriptase (TERT) gene promoter mutations have been explored, as biomarkers of improved survival for patients with cancer receiving immune checkpoint inhibitors. We sought to investigate their prevalence by race and sex across different cancer types to inform patient selection in clinical trials. RESULTS In this observational study, 31 925 patients with cancer underwent next-generation sequencing of their tumors with 88% (27 970) patients self-reported being Whites, 7.1% (2273) Asians, and 5.3% (1682) Blacks. Examining the distribution of TERT promoter mutations by race, White patients with melanoma harbored more TERT promoter mutations than Asian and Black patients (OR = 25.83; 95%CI, 6.84-217.42; P < .001). In contrast, Asian patients with head and neck cancer (HNC) harbored more TERT promoter mutations compared to White patients (OR = 2.47; 95%CI, 1.39-4.37; P = .004). In addition, the distribution of TERT promoter mutations differed by sex. Males were enriched for TERT gene promoter mutations compared to females with melanoma (OR = 1.82; 95%CI, 1.53-2.16; P < .001), cancer of unknown primary (OR = 1.96; 95%CI, 1.43-2.69; P < .001), hepatobiliary (OR = 3.89; 95%CI, 2.65-5.69; P < .001), and thyroid cancers (OR = 1.42; 95%CI, 1.10-1.84; P = .0087), while females were more enriched for TERT promoter mutations compared to males for HNC (OR = 0.56; 95%CI, 0.39-0.81; P = .0021). CONCLUSIONS The prevalence of TERT gene promoter mutations varies among patients with cancer based on race and sex. These findings inform our understanding of cancer biology and can assist in the design of future clinical trials that leverage drugs targeting TERT promoter dependencies.
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Affiliation(s)
- Talal El Zarif
- Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Department of Internal Medicine, Yale New Haven Hospital, New Haven, CT, USA
| | - Marc Machaalani
- Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon
| | - Rashad Nawfal
- Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon
| | - Amin H Nassar
- Department of Hematology/Oncology, Yale New Haven Hospital, New Haven, CT, USA
| | - Wanling Xie
- Department of Data Sciences, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Toni K Choueiri
- Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Mark Pomerantz
- Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
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Gómez‐Blanco D, Tobler M, Hasselquist D. Why and when should organisms elongate their telomeres? Elaborations on the 'excess resources elongation' and 'last resort elongation' hypotheses. Ecol Evol 2023; 13:e10825. [PMID: 38099139 PMCID: PMC10719541 DOI: 10.1002/ece3.10825] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 10/31/2023] [Accepted: 11/28/2023] [Indexed: 12/17/2023] Open
Abstract
Telomere length and telomere shortening are thought to be critical cellular attributes and processes that are related to an individual's life span and fitness. The general pattern across most taxa is that after birth telomere length gradually decreases with age. Telomere protection and restoration mechanisms are usually assumed to reduce the rate of shortening or at most keep telomere length constant. However, here we have compiled a list of 26 articles showing that there is an increasing number of studies reporting apparent elongation of telomeres (i.e., a net increase in TL from timet to timet+1) often in a considerable proportion of the individuals studied. Moreover, the few studies which have studied telomere elongation in detail show that increases in telomere length are unlikely to be due to measurement error alone. In this article, we argue that episodes of telomere elongation deserve more attention as they could reflect individual strategies to optimise life histories and maximise fitness, which may not be reflected in the overall telomere dynamics patterns. We propose that patterns of telomere (net) elongation may be partly determined by other factors than those causing telomere shortening, and therefore deserve analyses specifically targeted to investigate the occurrence of telomere elongation. We elaborate on two ecological hypotheses that have been proposed to explain patterns of telomere elongation (the 'excess resources elongation' and the 'last resort elongation' hypothesis) and we discuss the current evidence for (or against) these hypotheses and propose ways to test them.
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Wu X, Huang G, Li W, Chen Y. Ethnicity-specific association between TERT rs2736100 (A > C) polymorphism and lung cancer risk: a comprehensive meta-analysis. Sci Rep 2023; 13:13271. [PMID: 37582820 PMCID: PMC10427644 DOI: 10.1038/s41598-023-40504-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 08/11/2023] [Indexed: 08/17/2023] Open
Abstract
The rs2736100 (A > C) polymorphism of the second intron of Telomerase reverse transcriptase (TERT) has been confirmed to be closely associated with the risk of Lung cancer (LC), but there is still no unified conclusion on the results of its association with LC. This study included Genome-wide association studies (GWAS) and case-control studies reported so far on this association between TERT rs2736100 polymorphism and LC to clarify such a correlation with LC and the differences in it between different ethnicities and different types of LC. Relevant literatures published before May 7, 2022 on 'TERT rs2736100 polymorphism and LC susceptibility' in PubMed, EMbase, CENTRAL, MEDLINE databases were searched through the Internet, and data were extracted. Statistical analysis of data was performed in Revman5.3 software, including drawing forest diagrams, drawing funnel diagrams and so on. Sensitivity and publication bias analysis were performed in Stata 12.0 software. The C allele of TERT rs2736100 was associated with the risk of LC (Overall population: [OR] = 1.21, 95%CI [1.17, 1.25]; Caucasians: [OR] = 1.11, 95%CI [1.06, 1.17]; Asians: [OR] = 1.26, 95%CI [1.21, 1.30]), and Asians had a higher risk of LC than Caucasians (C vs. A: Caucasians: [OR] = 1.11 /Asians: [OR]) = 1.26). The other gene models also showed similar results. The results of stratified analysis of LC patients showed that the C allele was associated with the risk of Non-small-cell lung carcinoma (NSCLC) and Lung adenocarcinoma (LUAD), and the risk of NSCLC and LUAD in Asians was higher than that in Caucasians. The C allele was associated with the risk of Lung squamous cell carcinoma (LUSC) and Small cell lung carcinoma(SCLC) in Asians but not in Caucasians. NSCLC patients ([OR] = 1.27) had a stronger correlation than SCLC patients ([OR] = 1.03), and LUAD patients ([OR] = 1.32) had a stronger correlation than LUSC patients ([OR] = 1.09).In addition, the C allele of TERT rs2736100 was associated with the risk of LC, NSCLC and LUAD in both smoking groups and non-smoking groups, and the risk of LC in non-smokers of different ethnic groups was higher than that in smokers. In the Asians, non-smoking women were more at risk of developing LUAD. The C allele of TERT rs2736100 is a risk factor for LC, NSCLC, and LUAD in different ethnic groups, and the Asian population is at a more common risk. The C allele is a risk factor for LUSC and SCLC in Asians but not in Caucasians. And smoking is not the most critical factor that causes variation in TERT rs2736100 to increase the risk of most LC (NSCLC, LUAD). Therefore, LC is a multi-etiological disease caused by a combination of genetic, environmental and lifestyle factors.
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Affiliation(s)
- Xiaozheng Wu
- Department of Preclinical Medicine, Guizhou University of Traditional Chinese Medicine, Guiyang, 510025, China
| | - Gao Huang
- Department of Preclinical Medicine, Guizhou University of Traditional Chinese Medicine, Guiyang, 510025, China
| | - Wen Li
- Department of Preclinical Medicine, Guizhou University of Traditional Chinese Medicine, Guiyang, 510025, China
| | - Yunzhi Chen
- Department of Preclinical Medicine, Guizhou University of Traditional Chinese Medicine, Guiyang, 510025, China.
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Chen Y, Wang J, Zhang F, Liu P. A perspective of immunotherapy for acute myeloid leukemia: Current advances and challenges. Front Pharmacol 2023; 14:1151032. [PMID: 37153761 PMCID: PMC10154606 DOI: 10.3389/fphar.2023.1151032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/24/2023] [Indexed: 05/10/2023] Open
Abstract
During the last decade, the underlying pathogenic mechanisms of acute myeloid leukemia (AML) have been the subject of extensive study which has considerably increased our understanding of the disease. However, both resistance to chemotherapy and disease relapse remain the principal obstacles to successful treatment. Because of acute and chronic undesirable effects frequently associated with conventional cytotoxic chemotherapy, consolidation chemotherapy is not feasible, especially for elderly patients, which has attracted a growing body of research to attempt to tackle this problem. Immunotherapies for acute myeloid leukemia, including immune checkpoint inhibitors, monoclonal antibodies, dendritic cell (DC) vaccines, together with T-cell therapy based on engineered antigen receptor have been developed recently. Our review presents the recent progress in immunotherapy for the treatment of AML and discusses effective therapies that have the most potential and major challenges.
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Affiliation(s)
- Ying Chen
- Department of Hematology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
- Guizhou Province Institute of Hematology, Guizhou Province Laboratory of Hematopoietic Stem Cell Transplantation Centre, Guiyang, China
| | - Jishi Wang
- Department of Hematology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
- Guizhou Province Institute of Hematology, Guizhou Province Laboratory of Hematopoietic Stem Cell Transplantation Centre, Guiyang, China
- *Correspondence: Jishi Wang,
| | - Fengqi Zhang
- Department of Hematology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
- Guizhou Province Institute of Hematology, Guizhou Province Laboratory of Hematopoietic Stem Cell Transplantation Centre, Guiyang, China
| | - Ping Liu
- Department of Hematology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
- Guizhou Province Institute of Hematology, Guizhou Province Laboratory of Hematopoietic Stem Cell Transplantation Centre, Guiyang, China
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Targeting visualization of malignant tumor based on the alteration of DWI signal generated by hTERT promoter–driven AQP1 overexpression. Eur J Nucl Med Mol Imaging 2022; 49:2310-2322. [DOI: 10.1007/s00259-022-05684-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 01/09/2022] [Indexed: 02/07/2023]
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Stainczyk SA, Westermann F. Neuroblastoma-Telomere maintenance, deregulated signaling transduction and beyond. Int J Cancer 2021; 150:903-915. [PMID: 34636058 DOI: 10.1002/ijc.33839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 09/06/2021] [Accepted: 09/27/2021] [Indexed: 11/11/2022]
Abstract
The childhood malignancy neuroblastoma belongs to the group of embryonal tumors and originates from progenitor cells of the sympathoadrenal lineage. Treatment options for children with high-risk and relapsed disease are still very limited. In recent years, an ever-growing molecular diversity was identified using (epi)-genetic profiling of neuroblastoma tumors, indicating that molecularly targeted therapies could be a promising therapeutic option. In this review article, we summarize the various molecular subtypes and genetic events associated with neuroblastoma and describe recent advances in targeted therapies. We lay a strong emphasis on the importance of telomere maintenance mechanisms for understanding tumor progression and risk classification of neuroblastoma.
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Affiliation(s)
- Sabine A Stainczyk
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany.,Neuroblastoma Genomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Frank Westermann
- Hopp Children's Cancer Center (KiTZ), Heidelberg, Germany.,Neuroblastoma Genomics, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Telomeres: New players in immune-mediated inflammatory diseases? J Autoimmun 2021; 123:102699. [PMID: 34265700 DOI: 10.1016/j.jaut.2021.102699] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 12/21/2022]
Abstract
Telomeres are repetitive DNA sequences located at the ends of linear chromosomes that preserve the integrity and stability of the genome. Telomere dysfunctions due to short telomeres or altered telomere structures can ultimately lead to replicative cellular senescence and chromosomal instability, both mechanisms being hallmarks of ageing. Chronic inflammation, oxidative stress and finally telomere length (TL) dynamics have been shown to be involved in various age-related non-communicable diseases (NCDs). Immune-mediated inflammatory diseases (IMIDs), including affections such as inflammatory bowel disease, psoriasis, rheumatoid arthritis, spondyloarthritis and uveitis belong to this group of age-related NCDs. Although in recent years, we have witnessed the emergence of studies in the literature linking these IMIDs to TL dynamics, the causality between these diseases and telomere attrition is still unclear and controversial. In this review, we provide an overview of available studies on telomere dynamics and discuss the utility of TL measurements in immune-mediated inflammatory diseases.
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TERT Gene rs2736100 and rs2736098 Polymorphisms are Associated with Increased Cancer Risk: A Meta-Analysis. Biochem Genet 2021; 60:241-266. [PMID: 34181135 DOI: 10.1007/s10528-021-10097-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/09/2021] [Indexed: 10/21/2022]
Abstract
Abnormal telomerase activity plays a key role in the development of carcinogenesis. The variants rs2736100 and rs2736098 of the telomerase reverse transcriptase (TERT) gene, which encodes the telomerase catalytic subunit, are associated with the risk of different types of cancers. However, the results remain controversy. We conducted a meta-analysis to more precisely assess this association. We comprehensively searched the PubMed and Web of Science databases up to June 1, 2020, and retrieved a total of 103 studies in 82 articles, including 89,320 cases and 121,654 controls. Among these studies, 69 published studies including 75,274 cases and 10,3248 controls were focused on rs2736100, and 34 published studies including 14,046 cases and 18,362 controls were focused on rs2736098. The results showed a strong association between variant rs2736100 and cancer risk in all populations. (G vs. T: OR 1.18, 95% CI 1.12-1.24; TG+GG vs. TT: OR 1.23, 95% CI 1.15-1.31; GG vs. TG+TT: OR 1.25, 95% CI 1.16-1.36); the variant rs2736098 was associated with cancer risk in all populations as well (A vs. G: OR 1.13, 95% CI 1.05-1.22; GA+AA vs. GG: OR 1.15, 95% CI 1.04-1.27; AA vs. GA+GG: OR 1.22, 95% CI 1.10-1.38). Stratified analysis based on the cancer type indicated that rs2736100 was associated with an increased risk of thyroid cancer, bladder cancer, lung cancer, glioma, and myeloproliferative neoplasms. rs2736098 only increased the risk of bladder cancer and lung cancer. Moreover, the TERT variants rs2736100 and rs2736098 were associated with a decreased risk of breast cancer and colorectal cancer. The variants rs2736098 and rs2736100 located in 5p15.33 around TERT were associated with increased cancer risk in all populations. These two variants had bidirectional effects in different tumors.
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Kour A, Sambyal V, Guleria K, Singh NR, Uppal MS, Manjari M, Sudan M. In silico pathway analysis based on chromosomal instability in breast cancer patients. BMC Med Genomics 2020; 13:168. [PMID: 33167967 PMCID: PMC7653868 DOI: 10.1186/s12920-020-00811-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 06/11/2020] [Indexed: 02/15/2023] Open
Abstract
BACKGROUND Complex genomic changes that arise in tumors are a consequence of chromosomal instability. In tumor cells genomic aberrations disrupt core signaling pathways involving various genes, thus delineating of signaling pathways can help understand the pathogenesis of cancer. The bioinformatics tools can further help in identifying networks of interactions between the genes to get a greater biological context of all genes affected by chromosomal instability. METHODS Karyotypic analyses was done in 150 clinically confirmed breast cancer patients and 150 age and gender matched healthy controls after 72 h Peripheral lymphocyte culturing and GTG-banding. Reactome database from Cytoscape software version 3.7.1 was used to perform in-silico analysis (functional interaction and gene enrichment). RESULTS Frequency of chromosomal aberrations (structural and numerical) was found to be significantly higher in patients as compared to controls. The genes harbored by chromosomal regions showing increased aberration frequency in patients were further analyzed in-silico. Pathway analysis on a set of genes that were not linked together revealed that genes HDAC3, NCOA1, NLRC4, COL1A1, RARA, WWTR1, and BRCA1 were enriched in the RNA Polymerase II Transcription pathway which is involved in recruitment, initiation, elongation and dissociation during transcription. CONCLUSION The current study employs the information inferred from chromosomal instability analysis in a non-target tissue for determining the genes and the pathways associated with breast cancer. These results can be further extrapolated by performing either mutation analysis in the genes/pathways deduced or expression analysis which can pinpoint the relevant functional impact of chromosomal instability.
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Affiliation(s)
- Akeen Kour
- Human Cytogenetics Laboratory, Department of Human Genetics, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Vasudha Sambyal
- Human Cytogenetics Laboratory, Department of Human Genetics, Guru Nanak Dev University, Amritsar, Punjab, India.
| | - Kamlesh Guleria
- Human Cytogenetics Laboratory, Department of Human Genetics, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Neeti Rajan Singh
- Department of Surgery, Sri Guru Ram Das Institute of Medical Sciences and Research, Vallah, Amritsar, Punjab, India
| | - Manjit Singh Uppal
- Department of Surgery, Sri Guru Ram Das Institute of Medical Sciences and Research, Vallah, Amritsar, Punjab, India
| | - Mridu Manjari
- Department of Pathology, Sri Guru Ram Das Institute of Medical Sciences and Research, Vallah, Amritsar, Punjab, India
| | - Meena Sudan
- Department of Radiotherapy, Sri Guru Ram Das Institute of Medical Sciences and Research, Vallah, Amritsar, Punjab, India
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Overgaard NH, Fan TM, Schachtschneider KM, Principe DR, Schook LB, Jungersen G. Of Mice, Dogs, Pigs, and Men: Choosing the Appropriate Model for Immuno-Oncology Research. ILAR J 2019; 59:247-262. [PMID: 30476148 DOI: 10.1093/ilar/ily014] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 07/30/2018] [Indexed: 02/06/2023] Open
Abstract
The immune system plays dual roles in response to cancer. The host immune system protects against tumor formation via immunosurveillance; however, recognition of the tumor by immune cells also induces sculpting mechanisms leading to a Darwinian selection of tumor cell variants with reduced immunogenicity. Cancer immunoediting is the concept used to describe the complex interplay between tumor cells and the immune system. This concept, commonly referred to as the three E's, is encompassed by 3 distinct phases of elimination, equilibrium, and escape. Despite impressive results in the clinic, cancer immunotherapy still has room for improvement as many patients remain unresponsive to therapy. Moreover, many of the preclinical results obtained in the widely used mouse models of cancer are lost in translation to human patients. To improve the success rate of immuno-oncology research and preclinical testing of immune-based anticancer therapies, using alternative animal models more closely related to humans is a promising approach. Here, we describe 2 of the major alternative model systems: canine (spontaneous) and porcine (experimental) cancer models. Although dogs display a high rate of spontaneous tumor formation, an increased number of genetically modified porcine models exist. We suggest that the optimal immuno-oncology model may depend on the stage of cancer immunoediting in question. In particular, the spontaneous canine tumor models provide a unique platform for evaluating therapies aimed at the escape phase of cancer, while genetically engineered swine allow for elucidation of tumor-immune cell interactions especially during the phases of elimination and equilibrium.
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Affiliation(s)
- Nana H Overgaard
- Department of Micro- and Nanotechnology, Technical University of Denmark, Kgs Lyngby, Denmark
| | - Timothy M Fan
- Department of Veterinary Clinical Medicine, University of Illinois, Urbana-Champaign, Illinois
| | | | - Daniel R Principe
- Medical Scientist Training Program, University of Illinois College of Medicine, Chicago, Illinois
| | - Lawrence B Schook
- Department of Radiology, University of Illinois, Chicago, Illinois.,Department of Animal Sciences, University of Illinois, Urbana-Champaign, Illinois
| | - Gregers Jungersen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
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14
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Pompili L, Maresca C, Dello Stritto A, Biroccio A, Salvati E. BRCA2 Deletion Induces Alternative Lengthening of Telomeres in Telomerase Positive Colon Cancer Cells. Genes (Basel) 2019; 10:genes10090697. [PMID: 31510074 PMCID: PMC6771010 DOI: 10.3390/genes10090697] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/16/2019] [Accepted: 09/03/2019] [Indexed: 11/25/2022] Open
Abstract
BRCA1/2 are tumor suppressor genes controlling genomic stability also at telomeric and subtelomeric loci. Their mutation confers a predisposition to different human cancers but also sensitivity to antitumor drugs including poly(ADP-ribose) polymerase (PARP) inhibitors and G-quadruplex stabilizers. Here we demonstrate that BRCA2 deletion triggers TERRA hyperexpression and alternative lengthening mechanisms (ALT) in colon cancer cells in presence of telomerase activity. This finding opens the question if cancer patients bearing BRCA2 germline or sporadic mutation are suitable for anti-telomerase therapies, or how ALT activation could influence the short or long-term response to anti-PARP inhibitors or anti-G-quadruplex therapies.
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Affiliation(s)
- Luca Pompili
- Oncogenomic and Epigenetic Unit, IRCSS Regina Elena National Cancer Institute, Via Elio Chianesi, 53-00144 Rome, Italy.
| | - Carmen Maresca
- Oncogenomic and Epigenetic Unit, IRCSS Regina Elena National Cancer Institute, Via Elio Chianesi, 53-00144 Rome, Italy.
| | - Angela Dello Stritto
- Biology and Biotechnology Department "Charles Darwin", Sapienza University of Rome, Piazzale Aldo Moro, 5-00185 Rome, Italy.
| | - Annamaria Biroccio
- Oncogenomic and Epigenetic Unit, IRCSS Regina Elena National Cancer Institute, Via Elio Chianesi, 53-00144 Rome, Italy.
| | - Erica Salvati
- Oncogenomic and Epigenetic Unit, IRCSS Regina Elena National Cancer Institute, Via Elio Chianesi, 53-00144 Rome, Italy.
- Institute of Molecular Biology and Pathology, CNR, Via degli Apuli, 4-00185 Rome, Italy.
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15
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Overgaard NH, Principe DR, Schachtschneider KM, Jakobsen JT, Rund LA, Grippo PJ, Schook LB, Jungersen G. Genetically Induced Tumors in the Oncopig Model Invoke an Antitumor Immune Response Dominated by Cytotoxic CD8β + T Cells and Differentiated γδ T Cells Alongside a Regulatory Response Mediated by FOXP3 + T Cells and Immunoregulatory Molecules. Front Immunol 2018; 9:1301. [PMID: 29930558 PMCID: PMC5999797 DOI: 10.3389/fimmu.2018.01301] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 05/25/2018] [Indexed: 12/31/2022] Open
Abstract
In recent years, immunotherapy has shown considerable promise in the management of several malignancies. However, the majority of preclinical studies have been conducted in rodents, the results of which often translate poorly to patients given the substantial differences between murine and human immunology. As the porcine immune system is far more analogous to that of humans, pigs may serve as a supplementary preclinical model for future testing of such therapies. We have generated the genetically modified Oncopig with inducible tumor formation resulting from concomitant KRASG12D and TP53R167H mutations under control of an adenoviral vector Cre-recombinase (AdCre). The objective of this study was to characterize the tumor microenvironment in this novel animal model with respect to T-cell responses in particular and to elucidate the potential use of Oncopigs for future preclinical testing of cancer immunotherapies. In this study, we observed pronounced intratumoral T-cell infiltration with a strong CD8β+ predominance alongside a representation of highly differentiated γδ T cells. The infiltrating CD8β+ T cells displayed increased expression of the cytotoxic marker perforin when compared with the peripheral T-cell pool. Similarly, there was robust granzyme B staining localizing to the tumors; affirming the presence of cytotoxic immune cells within the tumor. In parallel with this antitumor immune response, the tumors displayed enrichment in FOXP3-expressing T cells and increased gene expression of indoleamine 2,3-dioxygenase 1 (IDO1), cytotoxic T-lymphocyte-associated protein 4 (CTLA4), and programmed death-ligand 1 (PDL1). Finally, we investigated the Oncopig immune system in mediating antitumor immunity. We observed pronounced killing of autologous tumor cells, which demonstrates the propensity of the Oncopig immune system to recognize and mount a cytotoxic response against tumor cells. Together, these findings suggest innate and adaptive recognition of the induced tumors with a concomitant in vivo suppression of T-cell effector functions. Combined, the data support that the Oncopig may serve as a valuable model for future preclinical testing of immunotherapies aimed at reactivating tumor-directed cytotoxicity in vivo.
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Affiliation(s)
- Nana H Overgaard
- Department of Micro- and Nanotechnology, Technical University of Denmark, Kongens Lyngby, Denmark.,Department of Animal Sciences, University of Illinois at Urbana-Champaign, Champaign, IL, United States
| | - Daniel R Principe
- Medical Scientist Training Program, University of Illinois College of Medicine, Chicago, IL, United States
| | | | - Jeanne Toft Jakobsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Laurie A Rund
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Champaign, IL, United States
| | - Paul J Grippo
- Department of Medicine, University of Illinois at Urbana-Champaign, Chicago, IL, United States
| | - Lawrence B Schook
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Champaign, IL, United States.,Department of Radiology, University of Illinois, Chicago, IL, United States
| | - Gregers Jungersen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
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16
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Inhibitor of the human telomerase reverse trancriptase (hTERT) gene promoter induces cell apoptosis via a mitochondrial-dependent pathway. Eur J Med Chem 2018; 145:370-378. [DOI: 10.1016/j.ejmech.2017.12.077] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 12/20/2017] [Accepted: 12/22/2017] [Indexed: 12/14/2022]
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17
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Khoury HJ, Collins RH, Blum W, Stiff PS, Elias L, Lebkowski JS, Reddy A, Nishimoto KP, Sen D, Wirth ED, Case CC, DiPersio JF. Immune responses and long-term disease recurrence status after telomerase-based dendritic cell immunotherapy in patients with acute myeloid leukemia. Cancer 2017; 123:3061-3072. [PMID: 28411378 DOI: 10.1002/cncr.30696] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 02/21/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Telomerase activity in leukemic blasts frequently is increased among patients with high-risk acute myeloid leukemia (AML). In the current study, the authors evaluated the feasibility, safety, immunogenicity, and therapeutic potential of human telomerase reverse transcriptase (hTERT)-expressing autologous dendritic cells (hTERT-DCs) in adult patients with AML. METHODS hTERT-DCs were produced from patient-specific leukapheresis, electroporated with an mRNA-encoding hTERT and a lysosomal-targeting sequence, and cryopreserved. A total of 22 patients with a median age of 58 years (range, 30-75 years) with intermediate-risk or high-risk AML in first or second complete remission (CR) were enrolled. hTERT-DCs were generated for 24 patients (73%). A median of 17 intradermal vaccinations (range, 6-32 intradermal vaccinations) containing 1×107 cells were administered as 6 weekly injections followed by 6 biweekly injections. A total of 21 patients (16 in first CR, 3 in second CR, and 2 with early disease recurrence) received hTERT-DCs. RESULTS hTERT-DCs were well tolerated with no severe toxicities reported, with the exception of 1 patient who developed idiopathic thrombocytopenic purpura. Of the 19 patients receiving hTERT-DCs in CR, 11 patients (58%) developed hTERT-specific T-cell responses that primarily were targeted toward hTERT peptides with predicted low human leukocyte antigen (HLA)-binding affinities. With a median follow-up of 52 months, 58% of patients in CR (11 of 19 patients) were free of disease recurrence at the time of their last follow-up visit; 57% of the patients who were aged ≥60 years (4 of 7 patients) also were found to be free of disease recurrence at a median follow-up of 54 months. CONCLUSIONS The generation of hTERT-DCs is feasible and vaccination with hTERT-DCs appears to be safe and may be associated with favorable recurrence-free survival. Cancer 2017;123:3061-72. © 2017 American Cancer Society.
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Affiliation(s)
- Hanna J Khoury
- Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, Georgia
| | - Robert H Collins
- Department of Internal Medicine, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
| | - William Blum
- Department of Hematology, The Ohio State University, Columbus, Ohio
| | - Patrick S Stiff
- Department of Medicine, Loyola University, Maywood, Illinois
| | | | | | | | | | - Debasish Sen
- Asterias Biotherapeutics Inc, Menlo Park, California
| | | | - Casey C Case
- Asterias Biotherapeutics Inc, Menlo Park, California
| | - John F DiPersio
- Department of Oncology, Washington University School of Medicine, St. Louis, Missouri
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18
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El Beshlawy A, Said F, El Ansary M, Hamdy M, Abdel-Azim K, Abdel-Razek ARA, Abulata N, Abdel-Salam A. Telomerase enzyme activity in Egyptian children with bone marrow failure and response to immunosuppressive therapy. Blood Cells Mol Dis 2017; 63:58-61. [PMID: 28160733 DOI: 10.1016/j.bcmd.2017.01.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 11/26/2022]
Affiliation(s)
| | - Fadwa Said
- Clinical and Chemical Pathology Department, Cairo University, Egypt.
| | - Mervat El Ansary
- Clinical and Chemical Pathology Department, Cairo University, Egypt.
| | - Mona Hamdy
- Pediatric Hematology Department, Cairo University, Egypt.
| | | | | | - Nelly Abulata
- Clinical and Chemical Pathology Department, Cairo University, Egypt.
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19
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Bailon-Moscoso N, Cevallos-Solorzano G, Romero-Benavides JC, Orellana MIR. Natural Compounds as Modulators of Cell Cycle Arrest: Application for Anticancer Chemotherapies. Curr Genomics 2017; 18:106-131. [PMID: 28367072 PMCID: PMC5345333 DOI: 10.2174/1389202917666160808125645] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 11/13/2015] [Accepted: 11/20/2015] [Indexed: 12/22/2022] Open
Abstract
Natural compounds from various plants, microorganisms and marine species play an important role in the discovery novel components that can be successfully used in numerous biomedical applications, including anticancer therapeutics. Since uncontrolled and rapid cell division is a hallmark of cancer, unraveling the molecular mechanisms underlying mitosis is key to understanding how various natural compounds might function as inhibitors of cell cycle progression. A number of natural compounds that inhibit the cell cycle arrest have proven effective for killing cancer cells in vitro, in vivo and in clinical settings. Significant advances that have been recently made in the understanding of molecular mechanisms underlying the cell cycle regulation using the chemotherapeutic agents is of great importance for improving the efficacy of targeted therapeutics and overcoming resistance to anticancer drugs, especially of natural origin, which inhibit the activities of cyclins and cyclin-dependent kinases, as well as other proteins and enzymes involved in proper regulation of cell cycle leading to controlled cell proliferation.
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20
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Dhanasekaran R, Bandoh S, Roberts LR. Molecular pathogenesis of hepatocellular carcinoma and impact of therapeutic advances. F1000Res 2016; 5. [PMID: 27239288 PMCID: PMC4870992 DOI: 10.12688/f1000research.6946.1] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/21/2016] [Indexed: 12/14/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality and has an increasing incidence worldwide. HCC can be induced by multiple etiologies, is influenced by many risk factors, and has a complex pathogenesis. Furthermore, HCCs exhibit substantial heterogeneity, which compounds the difficulties in developing effective therapies against this highly lethal cancer. With advances in cancer biology and molecular and genetic profiling, a number of different mechanisms involved in the development and progression of HCC have been identified. Despite the advances in this area, the molecular pathogenesis of hepatocellular carcinoma is still not completely understood. This review aims to elaborate our current understanding of the most relevant genetic alterations and molecular pathways involved in the development and progression of HCC, and anticipate the potential impact of future advances on therapeutic drug development.
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Affiliation(s)
| | - Salome Bandoh
- Department of Medicine, Korle-Bu Teaching Hospital, Accra, Ghana
| | - Lewis R Roberts
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN, USA
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21
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Fragkiadaki P, Tsoukalas D, Fragkiadoulaki I, Psycharakis C, Nikitovic D, Spandidos DA, Tsatsakis AM. Telomerase activity in pregnancy complications (Review). Mol Med Rep 2016; 14:16-21. [PMID: 27175856 PMCID: PMC4918539 DOI: 10.3892/mmr.2016.5231] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 05/02/2016] [Indexed: 12/14/2022] Open
Abstract
Telomeres are specific DNA regions positioned at the ends of chromosomes and composed of functional non-coding repeats. Upon cell division, the telomeres decrease in length by a preordained amount. When the telomeres become critically short, cells lose the ability to divide and enter a specific functioning mode designated as 'cellular senescence'. However, human tissues express an enzyme that deters the shrinking of the telomeres, the telomerase. Due to its ability to maintain telomere length, the telomerase slows down and possibly suspends the aging of the cells. In regard to this, solid evidence demonstrates that female human fertility decreases with increased maternal age and that various adverse factors, including alterations in telomerase activity, can contribute to age-associated infertility in women. The fact that telomerase activity is regulated in a time- and location-dependent manner in both embryo and placental tissues, highlights it potential importance to the successful completion of pregnancy. Since maternal age is a crucial determining factor for the success of in vitro and in vivo fertilization, numerous studies have focused on telomerase activity and its correlation with mammalian fertilization, as well as the following cleavage and pre-implantation developmental processes. Associations between telomerase activity and pregnancy complications have been previously observed. Our aim in this review was to summarize and critically discuss evidence correlating telomerase activity with pregnancy complications.
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Affiliation(s)
- Persefoni Fragkiadaki
- Center of Toxicology Science and Research, University of Crete, Heraklion 71003, Greece
| | - Dimitrios Tsoukalas
- Center of Toxicology Science and Research, University of Crete, Heraklion 71003, Greece
| | - Irini Fragkiadoulaki
- Center of Toxicology Science and Research, University of Crete, Heraklion 71003, Greece
| | - Christos Psycharakis
- Center of Toxicology Science and Research, University of Crete, Heraklion 71003, Greece
| | - Dragana Nikitovic
- Laboratory of Anatomy‑Histology‑Embryology, School of Medicine, University of Crete, Heraklion 71003, Greece
| | - Demetrios A Spandidos
- Laboratory of Clinical Virology, School of Medicine, University of Crete, Heraklion 71003, Greece
| | - Aristides M Tsatsakis
- Center of Toxicology Science and Research, University of Crete, Heraklion 71003, Greece
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22
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Lee S, Barnhill RL, Dummer R, Dalton J, Wu J, Pappo A, Bahrami A. TERT Promoter Mutations Are Predictive of Aggressive Clinical Behavior in Patients with Spitzoid Melanocytic Neoplasms. Sci Rep 2015; 5:11200. [PMID: 26061100 PMCID: PMC4462090 DOI: 10.1038/srep11200] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/30/2015] [Indexed: 12/15/2022] Open
Abstract
Spitzoid neoplasms constitute a morphologically distinct category of melanocytic tumors, encompassing Spitz nevus (benign), atypical Spitz tumor (intermediate malignant potential), and spitzoid melanoma (fully malignant). Currently, no reliable histopathological criteria or molecular marker is known to distinguish borderline from overtly malignant neoplasms. Because TERT promoter (TERT-p) mutations are common in inherently aggressive cutaneous conventional melanoma, we sought to evaluate their prognostic significance in spitzoid neoplasms. We analyzed tumors labeled as atypical Spitz tumor or spitzoid melanoma from 56 patients with available follow-up data for the association of TERT-p mutations, biallelic CDKN2A deletion, biallelic PTEN deletion, kinase fusions, BRAF/NRAS mutations, nodal status, and histopathological parameters with risk of hematogenous metastasis. Four patients died of disseminated disease and 52 patients were alive and disease free without extranodal metastasis (median follow-up, 32.5 months). We found TERT-p mutations in samples from the 4 patients who developed hematogenous metastasis but in none of tumors from patients who had favorable outcomes. Presence of TERT-p mutations was the most significant predictor of haematogenous dissemination (P < 0.0001) among variables analyzed. We conclude that TERT-p mutations identify a clinically high-risk subset of patients with spitzoid tumors. Application of TERT-p mutational assays for risk stratification in the clinic requires large-scale validation.
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Affiliation(s)
- Seungjae Lee
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee, 38105, USA
| | - Raymond L Barnhill
- Département de BioPathologie, Institut Curie, 26 rue d'Ulm, 75248, Paris cedex 05, France
| | - Reinhard Dummer
- Department of Dermatology, University Hospital Zurich, Gloriastrasse 31, CH-8091 Zurich, Switzerland
| | - James Dalton
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee, 38105, USA
| | - Jianrong Wu
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, Tennessee, 38105, USA
| | - Alberto Pappo
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | - Armita Bahrami
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee, 38105, USA
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23
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Robles-Espinoza CD, Velasco-Herrera MDC, Hayward NK, Adams DJ. Telomere-regulating genes and the telomere interactome in familial cancers. Mol Cancer Res 2015; 13:211-22. [PMID: 25244922 PMCID: PMC4278843 DOI: 10.1158/1541-7786.mcr-14-0305] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Telomeres are repetitive sequence structures at the ends of linear chromosomes that consist of double-stranded DNA repeats followed by a short single-stranded DNA protrusion. Telomeres need to be replicated in each cell cycle and protected from DNA-processing enzymes, tasks that cells execute using specialized protein complexes such as telomerase (that includes TERT), which aids in telomere maintenance and replication, and the shelterin complex, which protects chromosome ends. These complexes are also able to interact with a variety of other proteins, referred to as the telomere interactome, to fulfill their biological functions and control signaling cascades originating from telomeres. Given their essential role in genomic maintenance and cell-cycle control, germline mutations in telomere-regulating proteins and their interacting partners have been found to underlie a variety of diseases and cancer-predisposition syndromes. These syndromes can be characterized by progressively shortening telomeres, in which carriers can present with organ failure due to stem cell senescence among other characteristics, or can also present with long or unprotected telomeres, providing an alternative route for cancer formation. This review summarizes the critical roles that telomere-regulating proteins play in cell-cycle control and cell fate and explores the current knowledge on different cancer-predisposing conditions that have been linked to germline defects in these proteins and their interacting partners.
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Affiliation(s)
| | | | - Nicholas K Hayward
- Oncogenomics Laboratory, QIMR Berghofer Medical Research Institute, Herston, Brisbane, Queensland, Australia
| | - David J Adams
- Experimental Cancer Genetics, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
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24
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Bisson F, Paquet C, Bourget JM, Zaniolo K, Rochette PJ, Landreville S, Damour O, Boudreau F, Auger FA, Guérin SL, Germain L. Contribution of Sp1 to Telomerase Expression and Activity in Skin Keratinocytes Cultured With a Feeder Layer. J Cell Physiol 2015; 230:308-17. [PMID: 24962522 DOI: 10.1002/jcp.24706] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 06/20/2014] [Indexed: 12/31/2022]
Abstract
The growth of primary keratinocytes is improved by culturing them with a feeder layer. The aim of this study was to assess whether the feeder layer increases the lifespan of cultured epithelial cells by maintaining or improving telomerase activity and expression. The addition of an irradiated fibroblast feeder layer of either human or mouse origin (i3T3) helped maintain telomerase activity as well as expression of the transcription factor Sp1 in cultured keratinocytes. In contrast, senescence occurred earlier, together with a reduction of Sp1 expression and telomerase activity, in keratinocytes cultured without a feeder layer. Telomerase activity was consistently higher in keratinocytes grown on the three different feeder layers tested relative to cells grown without them. Suppression of Sp1 expression by RNA inhibition (RNAi) reduced both telomerase expression and activity in keratinocytes and also abolished their long-term growth capacity suggesting that Sp1 is a key regulator of both telomerase gene expression and cell cycle progression of primary cultured human skin keratinocytes. The results of the present study therefore suggest that the beneficial influence of the feeder layer relies on its ability to preserve telomerase activity in cultured human keratinocytes through the maintenance of stable levels of Sp1 expression.
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Affiliation(s)
- Francis Bisson
- Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Université Laval, Québec, Canada
- Centre de Recherche FRQS du CHU de Québec, Québec, Canada
| | - Claudie Paquet
- Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Université Laval, Québec, Canada
- Centre de Recherche FRQS du CHU de Québec, Québec, Canada
| | - Jean-Michel Bourget
- Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Université Laval, Québec, Canada
- Centre de Recherche FRQS du CHU de Québec, Québec, Canada
| | - Karine Zaniolo
- Centre de Recherche FRQS du CHU de Québec, Québec, Canada
- CUO-Recherche, Québec, Canada
| | - Patrick J Rochette
- Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Université Laval, Québec, Canada
- Centre de Recherche FRQS du CHU de Québec, Québec, Canada
- CUO-Recherche, Québec, Canada
- Département d'Ophtalmologie et ORL-Chirurgie Cervico-Faciale, Faculté de Médecine, Université Laval, Québec, Canada
| | - Solange Landreville
- Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Université Laval, Québec, Canada
- Centre de Recherche FRQS du CHU de Québec, Québec, Canada
- CUO-Recherche, Québec, Canada
- Département d'Ophtalmologie et ORL-Chirurgie Cervico-Faciale, Faculté de Médecine, Université Laval, Québec, Canada
| | - Odile Damour
- Banque de Tissus et Cellules HCL, Laboratoire des Substituts Cutanés (LSC) CNRS UPR-412, Hôpital Edouard Herriot, Lyon, France
| | - François Boudreau
- Département d'Anatomie et de Biologie Cellulaire, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, Canada
| | - François A Auger
- Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Université Laval, Québec, Canada
- Centre de Recherche FRQS du CHU de Québec, Québec, Canada
- CUO-Recherche, Québec, Canada
- Département d'Ophtalmologie et ORL-Chirurgie Cervico-Faciale, Faculté de Médecine, Université Laval, Québec, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, Canada
| | - Sylvain L Guérin
- Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Université Laval, Québec, Canada
- Centre de Recherche FRQS du CHU de Québec, Québec, Canada
- CUO-Recherche, Québec, Canada
- Département d'Ophtalmologie et ORL-Chirurgie Cervico-Faciale, Faculté de Médecine, Université Laval, Québec, Canada
| | - Lucie Germain
- Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Université Laval, Québec, Canada
- Centre de Recherche FRQS du CHU de Québec, Québec, Canada
- CUO-Recherche, Québec, Canada
- Département d'Ophtalmologie et ORL-Chirurgie Cervico-Faciale, Faculté de Médecine, Université Laval, Québec, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec, Canada
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Gao J, Roy S, Tong L, Argos M, Jasmine F, Rahaman R, Rakibuz-Zaman M, Parvez F, Ahmed A, Hore SK, Sarwar G, Slavkovich V, Yunus M, Rahman M, Baron JA, Graziano JH, Ahsan H, Pierce BL. Arsenic exposure, telomere length, and expression of telomere-related genes among Bangladeshi individuals. ENVIRONMENTAL RESEARCH 2015; 136:462-9. [PMID: 25460668 PMCID: PMC4264833 DOI: 10.1016/j.envres.2014.09.040] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 08/11/2014] [Accepted: 09/22/2014] [Indexed: 05/19/2023]
Abstract
BACKGROUND Inorganic arsenic is a carcinogen whose mode of action may involve telomere dysfunction. Recent epidemiological studies suggest that chronic arsenic exposure is associated with longer telomeres and altered expression of telomere-related genes in peripheral blood. In this study, we evaluated the association of urinary arsenic concentration with expression of telomere-related genes and telomere length in Bangladeshi individuals with a wide range of arsenic exposure through naturally contaminated drinking water. METHODS We used linear regression models to estimate associations between urinary arsenic and array-based expression measures for 69 telomere related genes using mononuclear cell RNA samples from 1799 individuals. Association between arsenic exposure and a qPCR-based telomere length measure was assessed among 167 individuals. RESULTS Urinary arsenic was positively associated with expression of WRN, and negatively associated with TERF2, DKC1, TERF2IP and OBFC1 (all P<0.00035, Bonferroni-corrected threshold). We detected interaction between urinary arsenic and arsenic metabolism efficiency in relation to expression of WRN (P for interaction =0.00008). In addition, we observed that very high arsenic exposure was associated with longer telomeres compared to very low exposure (P=0.02). DISCUSSION Our findings suggest that arsenic's carcinogenic mode of action may involve alteration of telomere maintenance and/or telomere damage. This study extends our knowledge regarding the effect of arsenic on telomere length and expression of telomere-related genes.
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Affiliation(s)
- Jianjun Gao
- Department of Public Health Sciences, The University of Chicago, Chicago, IL 60637, USA
| | - Shantanu Roy
- Department of Public Health Sciences, The University of Chicago, Chicago, IL 60637, USA
| | - Lin Tong
- Department of Public Health Sciences, The University of Chicago, Chicago, IL 60637, USA
| | - Maria Argos
- Department of Public Health Sciences, The University of Chicago, Chicago, IL 60637, USA
| | - Farzana Jasmine
- Department of Public Health Sciences, The University of Chicago, Chicago, IL 60637, USA
| | - Ronald Rahaman
- Department of Public Health Sciences, The University of Chicago, Chicago, IL 60637, USA
| | | | - Faruque Parvez
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | | | - Samar K Hore
- International Center for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | | | - Vesna Slavkovich
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Mohammad Yunus
- International Center for Diarrheal Disease Research, Bangladesh, Dhaka, Bangladesh
| | | | - John A Baron
- University of North Carolina, Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27514, USA
| | - Joseph H Graziano
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Habibul Ahsan
- Department of Public Health Sciences, The University of Chicago, Chicago, IL 60637, USA; Comprehensive Cancer Center, The University of Chicago, Chicago, IL 60637, USA; Departments of Medicine and Human Genetics, The University of Chicago, Chicago, IL 60637, USA
| | - Brandon L Pierce
- Department of Public Health Sciences, The University of Chicago, Chicago, IL 60637, USA; Comprehensive Cancer Center, The University of Chicago, Chicago, IL 60637, USA.
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Queisser A, Heeg S, Thaler M, von Werder A, Opitz OG. Inhibition of telomerase induces alternative lengthening of telomeres during human esophageal carcinogenesis. Cancer Genet 2013; 206:374-86. [DOI: 10.1016/j.cancergen.2013.10.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 09/25/2013] [Accepted: 10/02/2013] [Indexed: 12/28/2022]
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Bollmann FM. Physiological and pathological significance of human telomerase reverse transcriptase splice variants. Biochimie 2013; 95:1965-70. [DOI: 10.1016/j.biochi.2013.07.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 07/29/2013] [Indexed: 12/22/2022]
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Alhazzazi TY, Kamarajan P, Verdin E, Kapila YL. Sirtuin-3 (SIRT3) and the Hallmarks of Cancer. Genes Cancer 2013; 4:164-71. [PMID: 24020007 DOI: 10.1177/1947601913486351] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Sirtuins (SIRT1-SIRT7), the mammalian homologs of the silent information regulator 2 (Sir2) in Saccharomyces cerevisiae, have been a major focus of study in the scientific community this past decade because of their emerging role in cancer biology and other age-related diseases. Emerging functions for this unique family of enzymes include roles in genomic stability, angiogenesis, metabolism, and anoikis. Here, we review recent developments on the role of sirtuins in cancer with a particular focus on SIRT3 and its role in the hallmarks of cancer and as a potential drug target for cancer treatment.
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Affiliation(s)
- Turki Y Alhazzazi
- Division of Oral Biology, Oral Basic and Clinical Sciences Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia ; Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
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Exclusion of exon 2 is a common mRNA splice variant of primate telomerase reverse transcriptases. PLoS One 2012; 7:e48016. [PMID: 23110161 PMCID: PMC3480478 DOI: 10.1371/journal.pone.0048016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 09/25/2012] [Indexed: 11/19/2022] Open
Abstract
Telomeric sequences are added by an enzyme called telomerase that is made of two components: a catalytic protein called telomerase reverse transcriptase (TERT) and an integral RNA template (TR). Telomerase expression is tightly regulated at each step of gene expression, including alternative splicing of TERT mRNA. While over a dozen different alternative splicing events have been reported for human TERT mRNA, these were all in the 3' half of the coding region. We were interested in examining splicing of the 5' half of hTERT mRNA, especially since exon 2 is unusually large (1.3 kb). Internal mammalian exons are usually short, typically only 50 to 300 nucleotides, and most long internal exons are alternatively processed. We used quantitative RT-PCR and high-throughput sequencing data to examine the variety and quantity of mRNA species generated from the hTERT locus. We determined that there are approximately 20-40 molecules of hTERT mRNA per cell in the A431 human cell line. In addition, we describe an abundant, alternatively-spliced mRNA variant that excludes TERT exon 2 and was seen in other primates. This variant causes a frameshift and results in translation termination in exon 3, generating a 12 kDa polypeptide.
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Li J, Zhang G, Liu T, Gu H, Yan L, Chen B. Construction of a novel vector expressing the fusion suicide gene yCDglyTK and hTERT-shRNA and its antitumor effects. Exp Ther Med 2012. [PMID: 23181115 PMCID: PMC3503886 DOI: 10.3892/etm.2012.613] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This study aimed to construct a novel recombinant expression vector, pcDNA3.1(-)hTERT-shRNA/yCDglyTK. Its bioactivity and antitumor effects were investigated in the SGC7901 human gastric cancer cell line. Interfering RNA (RNAi) targeting human telomerase reverse transcriptase (hTERT) was applied to construct the pYr1.1-hTERT-shRNA vector. The shRNA expression cassette (including U6 promoter) was subcloned into the pcDNA3.1(-) CV-yCDglyTK vector to build a new vector, pcDNA3.1(-) hTERT-shRNA/yCDglyTK, which was identified by restriction enzyme digestion and gene sequencing. All the plasmids were delivered into SGC7901 cells using calcium phosphate nanoparticles (CPNPs). Expression of yCDglyTK and hTERT was detected by immunofluorescence, real-time PCR and western blot analysis. MTT assays were applied to measure the cytotoxic effect of the plasmids with 5-fluorocytosine (5-FC). Cell apoptosis was detected by flow cytometry. Restriction enzyme digestion and gene sequencing confirmed that the recombinant vector pcDNA3.1(-)hTERT-shRNA/yCDglyTK had been successfully constructed. Immunofluorescence, real-time PCR and western blot analysis showed that yCDglyTK was expressed, and that hTERT expression was inhibited in cells transfected with the recombinant vector. The cells transfected with the recombinant vector were the most sensitive to 5-FC and the apoptosis rates of the cells were also increased. The pcDNA3.1(-)hTERTshRNA/yCDglyTK vector was constructed successfully; it was confirmed that targeting hTERT through RNAi could synergize with suicide gene therapy.
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Affiliation(s)
- Jia Li
- Department of Gastroenterology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
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Nikan M, Patrick BO, Sherman JC. Crystal Structure of a Template-Assembled Synthetic G-Quadruplex. Chembiochem 2012; 13:1413-5. [DOI: 10.1002/cbic.201200262] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Indexed: 01/24/2023]
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Hsu CC, Lee YC, Yeh SH, Chen CH, Wu CC, Wang TY, Chen YN, Hung LY, Liu YW, Chen HK, Hsiao YT, Wang WS, Tsou JH, Tsou YH, Wu MH, Chang WC, Lin DY. 58-kDa microspherule protein (MSP58) is novel Brahma-related gene 1 (BRG1)-associated protein that modulates p53/p21 senescence pathway. J Biol Chem 2012; 287:22533-48. [PMID: 22563078 PMCID: PMC3391125 DOI: 10.1074/jbc.m111.335331] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The nucleolar 58-kDa microspherule protein (MSP58) protein is a candidate oncogene implicated in modulating cellular proliferation and malignant transformation. In this study, we show that knocking down MSP58 expression caused aneuploidy and led to apoptosis, whereas ectopic expression of MSP58 regulated cell proliferation in a context-dependent manner. Specifically, ectopic expression of MSP58 in normal human IMR90 and Hs68 diploid fibroblasts, the H184B5F5/M10 mammary epithelial cell line, HT1080 fibrosarcoma cells, primary mouse embryonic fibroblasts, and immortalized NIH3T3 fibroblasts resulted in induction of premature senescence, an enlarged and flattened cellular morphology, and increased senescence-associated β-galactosidase activity. MSP58-driven senescence was strictly dependent on the presence of functional p53 as revealed by the fact that normal cells with p53 knockdown by specific shRNA or cells with a mutated or functionally impaired p53 pathway were effective in bypassing MSP58-induced senescence. At least two senescence mechanisms are induced by MSP58. First, MSP58 activates the DNA damage response and p53/p21 signaling pathways. Second, MSP58, p53, and the SWI/SNF chromatin-remodeling subunit Brahma-related gene 1 (BRG1) form a ternary complex on the p21 promoter and collaborate to activate p21. Additionally, MSP58 protein levels increased in cells undergoing replicative senescence and stress-induced senescence. Notably, the results of analyzing expression levels of MSP58 between tumors and matched normal tissues showed significant changes (both up- and down-regulation) in its expression in various types of tumors. Our findings highlight new aspects of MSP58 in modulating cellular senescence and suggest that MSP58 has both oncogenic and tumor-suppressive properties.
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Affiliation(s)
- Che-Chia Hsu
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan
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Hanna RK, Zhou C, Malloy KM, Sun L, Zhong Y, Gehrig PA, Bae-Jump VL. Metformin potentiates the effects of paclitaxel in endometrial cancer cells through inhibition of cell proliferation and modulation of the mTOR pathway. Gynecol Oncol 2012; 125:458-69. [PMID: 22252099 DOI: 10.1016/j.ygyno.2012.01.009] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 12/29/2011] [Accepted: 01/08/2012] [Indexed: 01/22/2023]
Abstract
OBJECTIVES To examine the effects of combination therapy with metformin and paclitaxel in endometrial cancer cell lines. METHODS ECC-1 and Ishikawa endometrial cancer cell lines were used. Cell proliferation was assessed after exposure to paclitaxel and metformin. Cell cycle progression was assessed by flow cytometry. hTERT expression was determined by real-time RT-PCR. Western immunoblotting was performed to determine the effect of metformin/paclitaxel on the mTOR pathway. RESULTS Paclitaxel inhibited proliferation in a dose-dependent manner in both cell lines with IC(50) values of 1-5nM and 5-10nM for Ishikawa and ECC-1 cells, respectively. Simultaneous exposure of cells to various doses of paclitaxel in combination with metformin (0.5mM) resulted in a significant synergistic anti-proliferative effect in both cell lines (Combination Index<1). Metformin induced G1 arrest in both cell lines. Paclitaxel alone or in combination with metformin resulted in predominantly G2 arrest. Metformin decreased hTERT mRNA expression while paclitaxel alone had no effect on telomerase activity. Metformin stimulated AMPK phosphorylation and decreased phosphorylation of the S6 protein. In contrast, paclitaxel inhibited AMPK phosphorylation in the ECC-1 cell line and induced phosphorylation of S6 in both cell lines. Treatment with metformin and paclitaxel resulted in decreased phosphorylation of S6 in both cell lines but only had an additive effect on AMPK phosphorylation in the ECC-1 cell line. CONCLUSIONS Metformin potentiates the effects of paclitaxel in endometrial cancer cells through inhibition of cell proliferation and modulation of the mTOR pathway. This combination may be a promising targeted therapy for endometrial cancer.
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Affiliation(s)
- Rabbie K Hanna
- University of North Carolina, Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, Chapel Hill, NC, USA
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Rampazzo E, Bonaldi L, Trentin L, Visco C, Keppel S, Giunco S, Frezzato F, Facco M, Novella E, Giaretta I, Del Bianco P, Semenzato G, De Rossi A. Telomere length and telomerase levels delineate subgroups of B-cell chronic lymphocytic leukemia with different biological characteristics and clinical outcomes. Haematologica 2011; 97:56-63. [PMID: 21933855 DOI: 10.3324/haematol.2011.049874] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND B-cell chronic lymphocytic leukemia is a clinically heterogeneous disease; some patients rapidly progress and die within a few years of diagnosis, whereas others have a long life expectancy with minimal or no treatment. Telomere length and telomerase levels have been proposed as prognostic factors; however, very few cases have been characterized for both parameters and no study has analyzed the prognostic value of the telomere/telomerase profile. DESIGN AND METHODS One hundred and seventy-three cases of chronic lymphocytic leukemia were characterized for telomere lengths and telomerase levels by real-time polymerase chain reaction. Data were correlated with established prognostic markers, IGVH mutational status and chromosomal aberrations, and clinical outcome. RESULTS Telomere lengths were inversely correlated with telomerase levels (r(s) = -0.213; P = 0.012), and most of the cases of chronic lymphocytic leukemia with high levels (above median) of telomerase had short (below median) telomeres (P = 0.0001). Telomerase levels were higher and telomeres were shorter in unmutated IGVH cases than in mutated IGVH ones (P<0.0001). Chronic lymphocytic leukemias with 11q, 17p deletion or 12 trisomy had significantly higher levels of telomerase and shorter telomeres than those with no chromosomal aberration or the sole 13q deletion (P < 0.001). Telomere length/telomerase level profiles identified subgroups of patients with different clinical outcomes (P < 0.0001), even within the subsets of chronic lymphocytic leukemia defined by IGVH mutational status or chromosomal aberrations. Short telomere/high telomerase profile was independently associated with more rapid disease progression. CONCLUSIONS Comprehensive analyses of telomeres, telomerase, chromosomal aberrations, and IGVH mutational status delineate groups of chronic lymphocytic leukemias with distinct biological characteristics and clinical outcomes. The telomere/telomerase profile may be particularly useful in refining the prognosis of chronic lymphocytic leukemia patients with mutated IGVH and no high-risk chromosomal aberrations.
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Affiliation(s)
- Enrica Rampazzo
- Department of Oncology and Surgical Sciences, Oncology Section, University of Padova,Padova, Italy
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Dalle Carbonare L, Gasparetto A, Donatelli L, Dellantonio A, Valenti MT. Telomerase mRNA detection in serum of patients with prostate cancer. Urol Oncol 2011; 31:205-10. [PMID: 21353795 DOI: 10.1016/j.urolonc.2010.12.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 12/07/2010] [Accepted: 12/28/2010] [Indexed: 02/03/2023]
Abstract
Telomerase functions as a reverse transcriptase enzyme in the process of telomere synthesis and telomerase activity have been detected in a large part of neoplastic tissues, whereas in normal somatic cells they were low or undetectable. The aim of this study was to investigate the telomerase mRNA detection in the serum of patients with a prostate tumor by using real-time reverse transcription PCR. The results were compared with biological samples obtained by age-matched normal donors and by patients with cardiovascular or metabolic diseases. Our data demonstrated that telomerase mRNA is detectable in the serum of patients with prostate cancer whereas it is not amplifiable in normal donors. This marker, assayed with the molecular method of quantitative PCR in serum, may be useful for diagnosing and monitoring prostate cancer patients.
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Bae-Jump VL, Zhou C, Boggess JF, Whang YE, Barroilhet L, Gehrig PA. Rapamycin inhibits cell proliferation in type I and type II endometrial carcinomas: a search for biomarkers of sensitivity to treatment. Gynecol Oncol 2010; 119:579-85. [PMID: 20863555 DOI: 10.1016/j.ygyno.2010.08.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 08/17/2010] [Accepted: 08/20/2010] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Our goal was to evaluate the effect of rapamycin, an mTOR inhibitor, in type I and II human endometrial cancer tumor explants. METHODS Short-term tissue culture with fresh endometrial cancer tumor explants was performed. Cell proliferation was assessed by MTS assay after treatment with rapamycin. Akt and PTEN status were documented by Western blotting. The effect of rapamycin on phosphorylated-S6 and 4E-BP-1 was also assessed by Western blotting. Real-time RT-PCR was used to quantify hTERT mRNA expression. Telomere length was determined by terminal restriction fragment Southern blotting. RESULTS Thirteen fresh endometrial cancer tumor explants (nine Type I, four Type II) were placed in short-term culture and treated with rapamycin. Nine of the endometrial cancer tumors responded to rapamycin, with a median IC₅₀ of 11.4 nM. Sensitivity to rapamycin was independent of PTEN and Akt status. Tumors (13/13) had a reduction in phosphorylated-S6 and 10/13 had a reduction in phosphorylated 4E-BP-1. Rapamycin decreased hTERT mRNA expression in all of the endometrial cancer tumors. Telomere length did not correspond with responsiveness to this drug. CONCLUSIONS Rapamycin demonstrated activity in fresh endometrial tumor explants independent of PTEN and Akt status. Some tumors demonstrated a reduction in phosphorylated-S6 and 4E-BP-1 without a significant change in cellular proliferation, suggesting that additional pathways may modulate cellular proliferation. Thus, mTOR inhibitors may be a useful targeted therapy for both type I and type II endometrial cancers, but the search remains for a predictive biomarker of sensitivity to this therapy.
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Affiliation(s)
- Victoria L Bae-Jump
- Department of Obstetrics and Gynecology, Division of Gynecologic Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Grimminger CM, Danenberg PV. Update of prognostic and predictive biomarkers in oropharyngeal squamous cell carcinoma: a review. Eur Arch Otorhinolaryngol 2010; 268:5-16. [PMID: 20827554 DOI: 10.1007/s00405-010-1369-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 08/12/2010] [Indexed: 01/10/2023]
Abstract
Oropharyngeal squamous cell carcinomas (OSCC) constitute about 5% of all cancers in the western world and the incidence and mortality rates of this tumor have shown little improvement over the last 30 years. Molecular targeted therapy, a promising strategy for the treatment of OSCC and other cancers, requires the understanding of specific molecular events of carcinogenesis and the different pathological, partly interrelated pathways. Extended knowledge of the prognostic or predictive value of molecular biomarkers in oropharyngeal cancer is necessary to allow a better characterization and classification of the tumor, improve the appraisal of clinical outcome and help to specify individual multimodal therapy with increased efficiency. This work affords an updated summary regarding recent data about tissue biomarkers in patients with OSCC, based on the six essential hallmarks of cancer described by Hanahan and Weinberg (Cell 100(1):57-70, 2000) providing the characterization of a malignant cell.
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Affiliation(s)
- Carolin M Grimminger
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, CA 90033, USA.
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Collie GW, Haider SM, Neidle S, Parkinson GN. A crystallographic and modelling study of a human telomeric RNA (TERRA) quadruplex. Nucleic Acids Res 2010; 38:5569-80. [PMID: 20413582 PMCID: PMC2938214 DOI: 10.1093/nar/gkq259] [Citation(s) in RCA: 186] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
DNA telomeric repeats in mammalian cells are transcribed to guanine-rich RNA sequences, which adopt parallel-stranded G-quadruplexes with a propeller-like fold. The successful crystallization and structure analysis of a bimolecular human telomeric RNA G-quadruplex, folded into the same crystalline environment as an equivalent DNA oligonucleotide sequence, is reported here. The structural basis of the increased stability of RNA telomeric quadruplexes over DNA ones and their preference for parallel topologies is described here. Our findings suggest that the 2′-OH hydroxyl groups in the RNA quadruplex play a significant role in redefining hydration structure in the grooves and the hydrogen bonding networks. The preference for specific nucleotides to populate the C3′-endo sugar pucker domain is accommodated by alterations in the phosphate backbone, which leads to greater stability through enhanced hydrogen bonding networks. Molecular dynamics simulations on the DNA and RNA quadruplexes are consistent with these findings. The computations, based on the native crystal structure, provide an explanation for RNA G-quadruplex ligand binding selectivity for a group of naphthalene diimide ligands as compared to the DNA G-quadruplex.
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Affiliation(s)
- Gavin W Collie
- Cancer Research UK Biomolecular Structure Group, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK
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Deraco M, Baratti D, Cabras AD, Zaffaroni N, Perrone F, Villa R, Jocollè J, Balestra MR, Kusamura S, Laterza B, Pilotti S. Experience with peritoneal mesothelioma at the Milan National Cancer Institute. World J Gastrointest Oncol 2010; 2:76-84. [PMID: 21160925 PMCID: PMC2999160 DOI: 10.4251/wjgo.v2.i2.76] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 11/06/2009] [Accepted: 11/13/2009] [Indexed: 02/05/2023] Open
Abstract
Diffuse malignant peritoneal mesothelioma (DMPM) is an uncommon and rapidly fatal tumor. Therapeutic options have traditionally been limited and ineffective. The biologic and molecular events correlated with poor responsiveness to therapy are still poorly understood. In recent years, an innovative treatment approach involving aggressive cytoreductive surgery (CRS) and perioperative intraperitoneal chemotherapy has reportedly resulted in improved outcome, as compared to historical controls. Since 1995, at the National Cancer Institute (NCI) of Milan (Italy), patients with DMPM have been treated with CRS and hyperthermic intra-peritoneal chemotherapy (HIPEC). In the present paper, clinical experiences and basic science investigations on DMPM at Milan NCI are reviewed. Peri-operative and long-term outcome results with CRS and HIPEC are presented. Clinico-pathological prognostic factors were investigated by multivariate analysis. The pathologic features and immunohistochemical markers related to DMPM biologic behavior were assessed in a large case-series uniformly treated at our institution. The prevalence and prognostic role of telomere maintenance mechanisms, which account for the limitless cell replicative potential of many malignancies, were studied. The dysregulation of the apoptotic pathways may play a role in the relative chemo-resistance of DMPM and a better understanding of apoptosis-related mechanisms could result in novel targeted therapeutic strategies. On this basis, the expression of survivin and other IAP family members (IAP-1, IAP-2, and X-IAP), the pro-apoptotic protein Smac/DIABLO, and antigens associated with cell proliferation (Ki-67) and apoptosis (caspase-cleaved cytokeratin-18) were analyzed. Finally, analyses of EGFR, PDGFRA and PDGFRB were performed to ascertain if deregulation of RTK could offer useful alternative therapeutic targets.
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Affiliation(s)
- Marcello Deraco
- Marcello Deraco, Dario Baratti, Maria Rosaria Balestra, Shigeki Kusamura, Barbara Laterza, Department of Surgery, National Cancer Institute, 20133 Milan, Italy
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Shafer A, Zhou C, Gehrig PA, Boggess JF, Bae-Jump VL. Rapamycin potentiates the effects of paclitaxel in endometrial cancer cells through inhibition of cell proliferation and induction of apoptosis. Int J Cancer 2010; 126:1144-54. [PMID: 19688827 DOI: 10.1002/ijc.24837] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Mammalian target of rapamycin (mTOR) inhibitors modulate signaling pathways involved in cell cycle progression, and recent phase II trials demonstrate activity in patients with endometrial cancer. Our objective was to examine the effects of combination therapy with rapamycin and paclitaxel in endometrial cancer cell lines. Paclitaxel inhibited proliferation in a dose-dependent manner in both cell lines with IC(50) values of 0.1-0.5 nM and 1-5 nM for Ishikawa and ECC-1 cells, respectively. To assess synergy of paclitaxel and rapamycin, the combination index (CI) was calculated by the method of Chou and Talalay. Simultaneous exposure of cells to various doses of paclitaxel in combination with rapamycin (1 nM) resulted in a significant synergistic anti-proliferative effect (CI <1, range 0.131-0.920). Rapamycin alone did not induce apoptosis, but combined treatment with paclitaxel increased apoptosis over that of paclitaxel alone. Treatment with rapamycin and paclitaxel resulted in decreased phosphorylation of S6 and 4E-BP1, two critical downstream targets of the mTOR pathway. Rapamycin decreased hTERT mRNA expression by real-time RT-PCR while paclitaxel alone had no effect on telomerase activity. Paclitaxel increased polymerization and acetylation of tubulin, and rapamycin appeared to enhance this effect. Thus, in conclusion, we demonstrate that rapamycin potentiates the effects of paclitaxel in endometrial cancer cells through inhibition of cell proliferation, induction of apoptosis and potentially increased polymerization and acetylation of tubulin. This suggests that the combination of rapamycin and paclitaxel may be a promising effective targeted therapy for endometrial cancer.
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Affiliation(s)
- Aaron Shafer
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, North Carolina 27599-7572, USA
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Kusamura S, Baratti D, Zaffaroni N, Villa R, Laterza B, Balestra MR, Deraco M. Pathophysiology and biology of peritoneal carcinomatosis. World J Gastrointest Oncol 2010; 2:12-8. [PMID: 21160812 PMCID: PMC2999153 DOI: 10.4251/wjgo.v2.i1.12] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 10/07/2009] [Accepted: 10/14/2009] [Indexed: 02/05/2023] Open
Abstract
Peritoneal carcinomatosis represents a devastating form of cancer progression with a very poor prognosis. Its complex pathogenesis is represented by a dynamic process comprising several steps. To the best of our knowledge pathogenesis can be partly explained by 3 major molecular pathways: (1) dissemination from the primary tumor; (2) primary tumor of peritoneum; and (3) independent origins of the primary tumor and peritoneal implants. These are not mutually exclusive and combinations of different mechanisms could occur inside a single case. There are still several aspects which need explanation by future studies. A comprehensive understanding of molecular events involved in peritoneal carcinomatosis is of paramount importance and should be systematically pursued not only to identify novel strategies for the prevention of the condition, but also to obtain therapeutic advances, through the identification of surrogate markers of prognosis and development of future molecular targeted therapies.
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Affiliation(s)
- Shigeki Kusamura
- Shigeki Kusamura, Dario Baratti, Barbara Laterza, Maria Rosaria Balestra, Marcello Deraco, Department of Surgery, National Cancer Institute of Milan, Via Venezian 1, 20133 Milano, Italy
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Roles for SUMO modification during senescence. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 694:160-71. [PMID: 20886763 DOI: 10.1007/978-1-4419-7002-2_12] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
SUMOylation is a reversible post-translational modification, where a small peptide (SUMO) is covalently attached to a target protein and changes its activity, subcellular localization and/or interaction with other macromolecules. SUMOylation substrates are numerous and diverse and modification by SUMO is involved in many biological functions, including the response to stress. The SUMO pathway has recently been implicated in the process of cellular senescence, the irreversible loss of cell replication potential that occurs during aging in vivo and in vitro. SUMO peptides, a SUMO E3 ligase and a SUMO-specific peptidase can induce or hinder the onset of senescence, thus supporting an association of SUMOylation with cell growth arrest and organismal aging. Preliminary results on comparative analysis ofproteomics and mRNA levels between young and old human and murine tissues show elevated levels of global protein SUMOylation and a decrease in components of the SUMOylation process with age. Further connections between the SUMO pathway and the aging process remain to be elucidated.
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Lee MS, Yaar M, Eller MS, Rünger TM, Gao Y, Gilchrest BA. Telomeric DNA induces p53-dependent reactive oxygen species and protects against oxidative damage. J Dermatol Sci 2009; 56:154-62. [PMID: 19906512 DOI: 10.1016/j.jdermsci.2009.08.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Revised: 07/20/2009] [Accepted: 08/24/2009] [Indexed: 01/12/2023]
Abstract
BACKGROUND Reactive oxygen species (ROS) are generated by cellular metabolism as well as by exogenous agents. While ROS can promote cellular senescence, they can also act as signaling molecules for processes that do not lead to senescence. Telomere homolog oligonucleotides (T-oligos) induce adaptive DNA damage responses including increased DNA repair capacity and these effects are mediated, at least in part, through p53. OBJECTIVE Studies were undertaken to determine whether such p53-mediated protective responses include enhanced antioxidant defenses. METHODS Normal human fibroblasts as well as R2F fibroblasts expressing wild type or dominant negative p53 were treated with an 11-base T-oligo, a complementary control oligo or diluents alone and then examined by western blot analysis, immunofluorescence microscopy and various biochemical assays. RESULTS We now report that T-oligo increases the level of the antioxidant enzymes superoxide dismutase 1 and 2 and protects cells from oxidative damage; and that telomere-based gammaH2AX (DNA damage) foci that form in response to T-oligos contain phosphorylated ATM and Chk2, proteins known to activate p53 and to mediate cell cycle arrest in response to oxidative stress. Further, T-oligo increases cellular ROS levels via a p53-dependent pathway, and these increases are abrogated by the NAD(P)H oxidase inhibitor diphenyliodonium chloride. CONCLUSION These results suggest the existence of innate telomere-based protective responses that act to reduce oxidative damage to cells. T-oligo treatment induces the same responses and offers a new model for studying intracellular ROS signaling and the relationships between DNA damage, ROS, oxidative stress, and cellular defense mechanisms.
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Affiliation(s)
- Margaret S Lee
- Department of Dermatology, Boston University School of Medicine, Boston, MA 02118, USA
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Cantrell LA, Zhou C, Mendivil A, Malloy KM, Gehrig PA, Bae-Jump VL. Metformin is a potent inhibitor of endometrial cancer cell proliferation--implications for a novel treatment strategy. Gynecol Oncol 2009; 116:92-8. [PMID: 19822355 DOI: 10.1016/j.ygyno.2009.09.024] [Citation(s) in RCA: 248] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Revised: 09/14/2009] [Accepted: 09/18/2009] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Obesity and diabetes are strong risk factors that drive the development of type I endometrial cancers. Recent epidemiological evidence suggests that metformin may lower cancer risk and reduce rates of cancer deaths among diabetic patients. In order to better understand metformin's anti-tumorigenic potential, our goal was to assess the effect of metformin on proliferation and expression of key targets of metformin cell signaling in endometrial cancer cell lines. METHODS The endometrial cancer cell lines, ECC-1 and Ishikawa, were used. Cell proliferation was assessed after exposure to metformin. Cell cycle progression was evaluated by flow cytometry. Apoptosis was assessed by ELISA for caspase-3 activity. hTERT expression was determined by real-time RT-PCR. Western immunoblotting was performed to determine the expression of the downstream targets of metformin. RESULTS Metformin potently inhibited growth in a dose-dependent manner in both cell lines (IC(50) of 1 mM). Treatment with metformin resulted in G1 arrest, induction of apoptosis and decreased hTERT expression. Western immunoblot analysis demonstrated that metformin induced phosphorylation of AMPK, its immediate downstream mediator, within 24 h of exposure. In parallel, treatment with metformin decreased phosphorylation of S6 protein, a key target of the mTOR pathway. CONCLUSIONS We find that metformin is a potent inhibitor of cell proliferation in endometrial cancer cell lines. This effect is partially mediated through AMPK activation and subsequent inhibition of the mTOR pathway. This work should provide the scientific foundation for future investigation of metformin as a strategy for endometrial cancer prevention and treatment.
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Affiliation(s)
- Leigh A Cantrell
- Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, CB #7572, Chapel Hill, NC 27599-7572, USA
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Kazemi Noureini S, Wink M. Transcriptional down regulation of hTERT and senescence induction in HepG2 cells by chelidonine. World J Gastroenterol 2009; 15:3603-10. [PMID: 19653337 PMCID: PMC2721233 DOI: 10.3748/wjg.15.3603] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [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 investigate the potential effects of chelidonine, the main alkaloid of Chelidonium majus, on telomerase activity and its regulation in HepG2 cells.
METHODS: Cytotoxicity of chelidonine for HepG2 cells was determined by neutral red assay. A modified polymerase chain reaction (PCR)-based telomerase repeat amplification protocol was used to estimate relative telomerase activity in chelidonine-treated cells in comparison with the untreated control cells. Relative expression level of the catalytic subunit of telomerase (hTERT) gene and P-glycoprotein (pgp) were estimated using semi-quantitative real-time reverse transcription-PCR (RT-PCR). Cell senescence in treated cells was demonstrated using a β-galactosidase test.
RESULTS: Cytotoxicity of chelidonine in HepG2 cells was not dose-dependent and tended to reach plateau immediately after the living cells were reduced in number to slightly higher than 50%. However, 12 &mgr;mol/L concentration of chelidonine was considered as LD50, where the maximal attainable effects were realized. Real-time RT-PCR data showed that the expression of pgp increased three-fold in chelidonine treated HepG2 cells in comparison with the untreated controls. Morphologically, treated HepG2 cells showed apoptotic features after 24 h and a small fraction of cells appeared with single blister cell death. The relative expression level of Bcl-2 dropped to less than 50% of control cells at a sub-apoptotic concentration of chelidonine and subsequently increased to higher than 120% at LD50. Telomerase activity was reduced considerably after administration of very low doses of chelidonine, whereas higher concentrations of chelidonine did not remarkably enhance the effect. Real-time RT-PCR experiments indicated a drastic decrease in expression level of hTERT subunit of telomerase under treatment with chelidonine. Repeated treatment of cells with very low doses of chelidonine caused a decline in growth rate by 4 wk and many of the cells appeared to be aged with large volume and dark staining in the β-galactosidase assay.
CONCLUSION: Chelidonine reduces telomerase activity through down-regulation of hTERT expression. Senescence induction might not be directly caused by reducing telomerase activity as it occurs after a few population doublings.
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Nikan M, Sherman JC. Cation-Complexation Behavior of Template-Assembled Synthetic G-Quartets. J Org Chem 2009; 74:5211-8. [DOI: 10.1021/jo9001245] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mehran Nikan
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, Canada V6T 1Z1
| | - John C. Sherman
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, Canada V6T 1Z1
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He Y, Wu Y, He X, Liu F, He X, Zhang Y. An immortalized goat mammary epithelial cell line induced with human telomerase reverse transcriptase (hTERT) gene transfer. Theriogenology 2009; 71:1417-24. [DOI: 10.1016/j.theriogenology.2009.01.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2008] [Revised: 12/14/2008] [Accepted: 01/13/2009] [Indexed: 11/26/2022]
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48
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Wu YH, Cheng ML, Ho HY, Chiu DTY, Wang TCV. Telomerase prevents accelerated senescence in glucose-6-phosphate dehydrogenase (G6PD)-deficient human fibroblasts. J Biomed Sci 2009; 16:18. [PMID: 19272180 PMCID: PMC2653519 DOI: 10.1186/1423-0127-16-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Accepted: 02/05/2009] [Indexed: 12/23/2022] Open
Abstract
Fibroblasts derived from glucose-6-phosphate dehydrogenase (G6PD)-deficient patients display retarded growth and accelerated cellular senescence that is attributable to increased accumulation of oxidative DNA damage and increased sensitivity to oxidant-induced senescence, but not to accelerated telomere attrition. Here, we show that ectopic expression of hTERT stimulates telomerase activity and prevents accelerated senescence in G6PD-deficient cells. Stable clones derived from hTERT-expressing normal and G6PD-deficient fibroblasts have normal karyotypes, and display no sign of senescence beyond 145 and 105 passages, respectively. Activation of telomerase, however, does not prevent telomere attrition in earlier-passage cells, but does stabilize telomere lengths at later passages. In addition, we provide evidence that ectopic expression of hTERT attenuates the increased sensitivity of G6PD-deficient fibroblasts to oxidant-induced senescence. These results suggest that ectopic expression of hTERT, in addition to acting in telomere length maintenance by activating telomerase, also functions in regulating senescence induction.
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Affiliation(s)
- Yi-Hsuan Wu
- Graduate Institute of Basic Medical Sciences, Chang Gung University, Kwei-San, Tao-Yuan 333, Taiwan.
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Distinct patterns of structural and numerical chromosomal instability characterize sporadic ovarian cancer. Neoplasia 2008; 10:1057-65. [PMID: 18813350 DOI: 10.1593/neo.08584] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Revised: 07/02/2008] [Accepted: 07/04/2008] [Indexed: 12/27/2022] Open
Abstract
Sporadic ovarian cancer is a particularly aggressive tumor characterized by highly abnormal karyotypes exhibiting many features of genomic instability. More complex genomic changes in tumors arise as a consequence of chromosomal instability (CIN), which can generate both numerical [(N)-CIN] and structural chromosomal instability [(S)-CIN]. In this study, molecular cytogenetic analysis was used to evaluate the relative levels of both (N)-CIN and (S)-CIN. Six tumors had a near-diploid chromosome number, two were near-tetraploid, and two were near-triploid. (N)-CIN levels increased as a function of overall tumor genomic content, with near-diploid tumors exhibiting numerical instability indices ranging from 7.0 to 21.0 and near-tetraploid and triploid tumors exhibiting instability indices ranging from 24.9 to 54.9. In contrast, the extent of (S)-CIN was generally more evident in the diploid tumors compared with the near-tetraploid tumors. To determine whether the associated chromosomal constitution and/or ploidy changes were influenced by mitotic segregation errors, centrosome analyses were performed on all 10 tumors. The near-diploid tumors, with the lowest numerical change, were observed to possess fewer cells with centrosome abnormalities (5.5% to 14.0%), whereas the near-tetraploid tumors possessed much higher levels of (N)-CIN and were characterized by a trend of elevating percentages of cells with abnormal centrosomes (16.0% to 20.5%). These observations suggest that two distinct processes governing genome stability may be disrupted in ovarian cancer: those that impact on numerical segregation and ploidy of chromosomes and those that affect the fidelity of DNA repair and lead to structural aberrations.
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Shao G, Balajee AS, Hei TK, Zhao Y. p16INK4a downregulation is involved in immortalization of primary human prostate epithelial cells induced by telomerase. Mol Carcinog 2008; 47:775-83. [PMID: 18383581 DOI: 10.1002/mc.20434] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Prostate cancer is a major cause of cancer death among male population. Therefore, development of appropriate model systems is critical for understanding the molecular basis of prostate cancer progression. In this study, introduction of human telomerase (hTERT) into normal human prostate epithelial cells (PrECs) renders them higher telomerase activity, elongated telomere length and an extended proliferative lifespan. The immortal mass culture of PrEC-hTERT cell line with stabilized telomere length has been established using hTERT transfection. However, activation of hTERT alone appears to be insufficient for immortalization of PrEC cells because methylation of p16(INK4a) promoter has been found to be involved in the immortalization process. p53 was functionally intact and no mutations of p53 gene were identified in the immortalized PrECs. In addition, the immortal PrECs show a near diploid complement of chromosomes albeit a few reciprocal and non-reciprocal translocations are identified. They are anchorage dependent and do not form tumors in immunosuppressed host animals. Therefore, premalignantly transformed human PrECs provide a valuable model for prostate cancer research.
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Affiliation(s)
- Genze Shao
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania, Pennsylvania, USA
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