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Wu N, Zheng W, Zhou Y, Tian Y, Tang M, Feng X, Ashrafizadeh M, Wang Y, Niu X, Tambuwala M, Wang L, Tergaonkar V, Sethi G, Klionsky D, Huang L, Gu M. Autophagy in aging-related diseases and cancer: Principles, regulatory mechanisms and therapeutic potential. Ageing Res Rev 2024; 100:102428. [PMID: 39038742 DOI: 10.1016/j.arr.2024.102428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Revised: 07/05/2024] [Accepted: 07/15/2024] [Indexed: 07/24/2024]
Abstract
Macroautophagy/autophagy is primarily accountable for the degradation of damaged organelles and toxic macromolecules in the cells. Regarding the essential function of autophagy for preserving cellular homeostasis, changes in, or dysfunction of, autophagy flux can lead to disease development. In the current paper, the complicated function of autophagy in aging-associated pathologies and cancer is evaluated, highlighting the underlying molecular mechanisms that can affect longevity and disease pathogenesis. As a natural biological process, a reduction in autophagy is observed with aging, resulting in an accumulation of cell damage and the development of different diseases, including neurological disorders, cardiovascular diseases, and cancer. The MTOR, AMPK, and ATG proteins demonstrate changes during aging, and they are promising therapeutic targets. Insulin/IGF1, TOR, PKA, AKT/PKB, caloric restriction and mitochondrial respiration are vital for lifespan regulation and can modulate or have an interaction with autophagy. The specific types of autophagy, such as mitophagy that degrades mitochondria, can regulate aging by affecting these organelles and eliminating those mitochondria with genomic mutations. Autophagy and its specific types contribute to the regulation of carcinogenesis and they are able to dually enhance or decrease cancer progression. Cancer hallmarks, including proliferation, metastasis, therapy resistance and immune reactions, are tightly regulated by autophagy, supporting the conclusion that autophagy is a promising target in cancer therapy.
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Affiliation(s)
- Na Wu
- Department of Infectious Diseases, The First Hospital of China Medical University, Shenyang, Liaoning 110001, China
| | - Wenhui Zheng
- Department of Anesthesiology, The Shengjing Hospital of China Medical University, Shenyang, Liaoning 110001, China
| | - Yundong Zhou
- Department of Thoracic Surgery, Ningbo Medical Center Lihuili Hospital, Ningbo University, Ningbo, Zhejiang 315040, China
| | - Yu Tian
- School of Public Health, Benedictine University, No.5700 College Road, Lisle, IL 60532, USA; Research Center, the Huizhou Central People's Hospital, Guangdong Medical University, Huizhou, Guangdong, China
| | - Min Tang
- Department of Oncology, Chongqing General Hospital, Chongqing University, Chongqing 401120, China
| | - Xiaoqiang Feng
- Center of Stem Cell and Regenerative Medicine, Gaozhou People's Hospital, Gaozhou, Guangdong 525200, China
| | - Milad Ashrafizadeh
- Department of Radiation Oncology, Shandong Provincial Key Laboratory of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University, Shandong Academy of Medical Sciences, Jinan, Shandong 250000, China; Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Yuzhuo Wang
- Department of Urologic Sciences and Vancouver Prostate Centre, University of British Columbia, Vancouver, BC V6H3Z6, Canada
| | - Xiaojia Niu
- Department of Urologic Sciences and Vancouver Prostate Centre, University of British Columbia, Vancouver, BC V6H3Z6, Canada
| | - Murtaza Tambuwala
- Lincoln Medical School, University of Lincoln, Brayford Pool Campus, Lincoln LN6 7TS, UK
| | - Lingzhi Wang
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 16 Medical Drive, Singapore 117600, Singapore
| | - Vinay Tergaonkar
- Laboratory of NF-κB Signalling, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A⁎STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 16 Medical Drive, Singapore 117600, Singapore; NUS Centre for Cancer Research (N2CR), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore.
| | - Daniel Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
| | - Li Huang
- Center of Stem Cell and Regenerative Medicine, Gaozhou People's Hospital, Gaozhou, Guangdong 525200, China.
| | - Ming Gu
- Department of Breast Surgery, The First Hospital of China Medical University, Shenyang, Liaoning 110001, China.
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2
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Ciclopirox drives growth arrest and autophagic cell death through STAT3 in gastric cancer cells. Cell Death Dis 2022; 13:1007. [PMID: 36443287 PMCID: PMC9705325 DOI: 10.1038/s41419-022-05456-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 11/29/2022]
Abstract
Ciclopirox (CPX), an antifungal drug, has recently been identified as a promising agent for cancer treatment. However, the effects and underlying mechanism of CPX as an antitumor agent of gastric cancer (GC) remain largely unknown. Here, we found that CPX dramatically suppresses GC xenograft growth in vitro via inhibiting proliferation and stimulating autophagic cell death rather than apoptosis. Moreover, CPX (20 mg/kg, intraperitoneally) substantially inhibits GC xenograft tumor growth in vivo. Mechanistically, CPX promotes growth arrest and autophagic cell death through suppressing the phosphorylation of signal transducers and activators of transcription 3 (STAT3) at tyrosine 705 (Tyr705) and serine 727 (Ser727) sites, respectively. Additionally, CPX induces STAT3 ubiquitination, which subsequently leads to a decrease in the p-STAT3 (Ser727) level. On the other hand, CPX represses the p-STAT3 (Tyr705) level via p-Src (Tyr416) inhibition. Collectively, our findings unmask a novel mechanism by which CPX regulates growth and autophagic cell death in GC cells via regulating the phosphorylation of STAT3 both at Tyr705 and Ser727 residues, and suggest that CPX may be a potential treatment for GC.
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3
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Tran M, Reddy PH. Defective Autophagy and Mitophagy in Aging and Alzheimer's Disease. Front Neurosci 2021; 14:612757. [PMID: 33488352 PMCID: PMC7820371 DOI: 10.3389/fnins.2020.612757] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022] Open
Abstract
Aging is the time-dependent process that all living organisms go through characterized by declining physiological function due to alterations in metabolic and molecular pathways. Many decades of research have been devoted to uncovering the cellular changes and progression of aging and have revealed that not all organisms with the same chronological age exhibit the same age-related declines in physiological function. In assessing biological age, factors such as epigenetic changes, telomere length, oxidative damage, and mitochondrial dysfunction in rescue mechanisms such as autophagy all play major roles. Recent studies have focused on autophagy dysfunction in aging, particularly on mitophagy due to its major role in energy generation and reactive oxidative species generation of mitochondria. Mitophagy has been implicated in playing a role in the pathogenesis of many age-related diseases, including Alzheimer's disease (AD), Parkinson's, Huntington's, and amyotrophic lateral sclerosis. The purpose of our article is to highlight the mechanisms of autophagy and mitophagy and how defects in these pathways contribute to the physiological markers of aging and AD. This article also discusses how mitochondrial dysfunction, abnormal mitochondrial dynamics, impaired biogenesis, and defective mitophagy are related to aging and AD progression. This article highlights recent studies of amyloid beta and phosphorylated tau in relation to autophagy and mitophagy in AD.
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Affiliation(s)
- Michael Tran
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - P. Hemachandra Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, United States
- Neuroscience and Pharmacology, Texas Tech University Health Sciences Center, Lubbock, TX, United States
- Neurology, Departments of School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, United States
- Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, United States
- Department of Speech, Language and Hearing Sciences, School Health Professions, Texas Tech University Health Sciences Center, Lubbock, TX, United States
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4
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Fundamental insights into the interaction between telomerase/TERT and intracellular signaling pathways. Biochimie 2020; 181:12-24. [PMID: 33232793 DOI: 10.1016/j.biochi.2020.11.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 11/07/2020] [Accepted: 11/16/2020] [Indexed: 12/12/2022]
Abstract
Telomerase activity is critical for cancer cells to provide unrestricted proliferation and cellular immortality through maintaining telomeres. Telomerase enzymatic activity is regulatable at the level of DNA, mRNA, post translational modifications, cellular transport and enzyme assembly. More recent studies confirm the interaction of the telomerase with various intracellular signaling pathways including PI3K/AKT/mTOR, NF-κB and Wnt/β-catenin which mainly participating in inflammation, epithelial to mesenchymal transition (EMT) and tumor cell invasion and metastasis. Furthermore, hTERT protein has been detected in non-nuclear sites such as the mitochondria and cytoplasm in cells. Mitochondrial TERT indicates various non-telomere-related functions such as decreasing reactive oxygen species (ROS) generation, boosting the respiration rate, protecting mtDNA by direct binding, interacting with mitochondrial tRNAs and increasing mitochondrial membrane potential which can lead to higher chemoresistance rate in cancer cells during therapies. Understanding the molecular mechanisms of the TERT function and depended interactions in tumor cells can suggest novel therapeutic approaches. Hence, in this review we will explain the telomerase activity regulation in translational and post translational levels besides the established correlations with various cell signaling pathways with possible pathways for therapeutic targeting.
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Structural Features of Nucleoprotein CST/Shelterin Complex Involved in the Telomere Maintenance and Its Association with Disease Mutations. Cells 2020; 9:cells9020359. [PMID: 32033110 PMCID: PMC7072152 DOI: 10.3390/cells9020359] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/23/2020] [Accepted: 01/24/2020] [Indexed: 12/29/2022] Open
Abstract
Telomere comprises the ends of eukaryotic linear chromosomes and is composed of G-rich (TTAGGG) tandem repeats which play an important role in maintaining genome stability, premature aging and onsets of many diseases. Majority of the telomere are replicated by conventional DNA replication, and only the last bit of the lagging strand is synthesized by telomerase (a reverse transcriptase). In addition to replication, telomere maintenance is principally carried out by two key complexes known as shelterin (TRF1, TRF2, TIN2, RAP1, POT1, and TPP1) and CST (CDC13/CTC1, STN1, and TEN1). Shelterin protects the telomere from DNA damage response (DDR) and regulates telomere length by telomerase; while, CST govern the extension of telomere by telomerase and C strand fill-in synthesis. We have investigated both structural and biochemical features of shelterin and CST complexes to get a clear understanding of their importance in the telomere maintenance. Further, we have analyzed ~115 clinically important mutations in both of the complexes. Association of such mutations with specific cellular fault unveils the importance of shelterin and CST complexes in the maintenance of genome stability. A possibility of targeting shelterin and CST by small molecule inhibitors is further investigated towards the therapeutic management of associated diseases. Overall, this review provides a possible direction to understand the mechanisms of telomere borne diseases, and their therapeutic intervention.
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6
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Cheon SY, Kim H, Rubinsztein DC, Lee JE. Autophagy, Cellular Aging and Age-related Human Diseases. Exp Neurobiol 2019; 28:643-657. [PMID: 31902153 PMCID: PMC6946111 DOI: 10.5607/en.2019.28.6.643] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/04/2019] [Accepted: 11/04/2019] [Indexed: 12/22/2022] Open
Abstract
Macroautophagy/autophagy is a conserved degradation system that engulfs intracytoplasmic contents, including aggregated proteins and organelles, which is crucial for cellular homeostasis. During aging, cellular factors suggested as the cause of aging have been reported to be associated with progressively compromised autophagy. Dysfunctional autophagy may contribute to age-related diseases, such as neurodegenerative disease, cancer, and metabolic syndrome, in the elderly. Therefore, restoration of impaired autophagy to normal may help to prevent age-related disease and extend lifespan and longevity. Therefore, this review aims to provide an overview of the mechanisms of autophagy underlying cellular aging and the consequent disease. Understanding the mechanisms of autophagy may provide potential information to aid therapeutic interventions in age-related diseases.
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Affiliation(s)
- So Yeong Cheon
- Department of Medical Genetics, Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge CB2 0XY, United Kingdom.,Department of Anatomy, Yonsei University College of Medicine, Seoul 03722, Korea
| | - Hyunjeong Kim
- Department of Medical Genetics, Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge CB2 0XY, United Kingdom.,Department of Anatomy, Yonsei University College of Medicine, Seoul 03722, Korea
| | - David C Rubinsztein
- Department of Medical Genetics, Cambridge Institute for Medical Research (CIMR), University of Cambridge, Cambridge CB2 0XY, United Kingdom.,UK Dementia Research Institute, University of Cambridge, Cambridge CB2 0AH, United Kingdom
| | - Jong Eun Lee
- Department of Anatomy, Yonsei University College of Medicine, Seoul 03722, Korea.,BK21 PLUS Project for Medical Science, and Brain Research Institute, Yonsei University College of Medicine, Seoul 03722, Korea
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7
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Schrank Z, Khan N, Osude C, Singh S, Miller RJ, Merrick C, Mabel A, Kuckovic A, Puri N. Oligonucleotides Targeting Telomeres and Telomerase in Cancer. Molecules 2018; 23:molecules23092267. [PMID: 30189661 PMCID: PMC6225148 DOI: 10.3390/molecules23092267] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 08/27/2018] [Accepted: 09/04/2018] [Indexed: 02/07/2023] Open
Abstract
Telomeres and telomerase have become attractive targets for the development of anticancer therapeutics due to their involvement in cancer cell immortality. Currently, several therapeutics have been developed that directly target telomerase and telomeres, such as telomerase inhibitors and G-quadruplex stabilizing ligands. Telomere-specific oligonucleotides that reduce telomerase activity and disrupt telomere architecture are also in development as novel anticancer therapeutics. Specifically, GRN163L and T-oligos have demonstrated promising anticancer activity in multiple cancers types via induction of potent DNA damage responses. Currently, several miRNAs have been implicated in the regulation of telomerase activity and may prove to be valuable targets in the development of novel therapies by reducing expression of telomerase subunits. Targeting miRNAs that are known to increase expression of telomerase subunits may be another strategy to reduce carcinogenesis. This review aims to provide a comprehensive understanding of current oligonucleotide-based anticancer therapies that target telomeres and telomerase. These studies may help design novel therapeutic approaches to overcome the challenges of oligonucleotide therapy in a clinical setting.
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Affiliation(s)
- Zachary Schrank
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA.
| | - Nabiha Khan
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA.
| | - Chike Osude
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA.
| | - Sanjana Singh
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA.
| | - Rachel J Miller
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA.
| | - Collin Merrick
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA.
| | - Alexander Mabel
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA.
| | - Adijan Kuckovic
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA.
| | - Neelu Puri
- Department of Biomedical Sciences, University of Illinois College of Medicine at Rockford, Rockford, IL 61107, USA.
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8
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Berardinelli F, Coluzzi E, Sgura A, Antoccia A. Targeting telomerase and telomeres to enhance ionizing radiation effects in in vitro and in vivo cancer models. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2017; 773:204-219. [PMID: 28927529 DOI: 10.1016/j.mrrev.2017.02.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 02/13/2017] [Accepted: 02/14/2017] [Indexed: 01/05/2023]
Abstract
One of the hallmarks of cancer consists in the ability of tumor cells to divide indefinitely, and to maintain stable telomere lengths throughout the activation of specific telomere maintenance mechanisms (TMM). Therefore in the last fifteen years, researchers proposed to target telomerase or telomeric structure in order to block limitless replicative potential of cancer cells providing a fascinating strategy for a broad-spectrum cancer therapy. In the present review, we report in vitro and in vivo evidence regarding the use of chemical agents targeting both telomerase or telomere structure and showing promising antitumor effects when used in combination with ionizing radiation (IR). RNA interference, antisense oligonucleotides (e.g., GRN163L), non-nucleoside inhibitors (e.g., BIBR1532) and nucleoside analogs (e.g., AZT) represent some of the most potent strategies to inhibit telomerase activity used in combination with IR. Furthermore, radiosensitizing effects were demonstrated also for agents acting directly on the telomeric structure such as G4-ligands (e.g., RHPS4 and Telomestatin) or telomeric-oligos (T-oligos). To date, some of these compounds are under clinical evaluation (e.g., GRN163L and KML001). Advantages of Telomere/Telomerase Targeting Compounds (T/TTCs) coupled with radiotherapy may be relevant in the treatment of radioresistant tumors and in the development of new optimized treatment plans with reduced dose adsorbed by patients and consequent attenuation of short- end long-term side effects. Pros and cons of possible future applications in cancer therapy based on the combination of T/TCCs and radiation treatment are discussed.
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Affiliation(s)
- F Berardinelli
- Dipartimento di Scienze, Università Roma Tre, Rome Italy; Istituto Nazionale di Fisica Nucleare, INFN, Sezione di Roma Tre, Rome, Italy.
| | - E Coluzzi
- Dipartimento di Scienze, Università Roma Tre, Rome Italy
| | - A Sgura
- Dipartimento di Scienze, Università Roma Tre, Rome Italy; Istituto Nazionale di Fisica Nucleare, INFN, Sezione di Roma Tre, Rome, Italy
| | - A Antoccia
- Dipartimento di Scienze, Università Roma Tre, Rome Italy; Istituto Nazionale di Fisica Nucleare, INFN, Sezione di Roma Tre, Rome, Italy
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Ouédraogo ZG, Biau J, Kemeny JL, Morel L, Verrelle P, Chautard E. Role of STAT3 in Genesis and Progression of Human Malignant Gliomas. Mol Neurobiol 2016; 54:5780-5797. [PMID: 27660268 DOI: 10.1007/s12035-016-0103-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 09/06/2016] [Indexed: 12/23/2022]
Abstract
Signal transducer and activator of transcription 3 (STAT3) is aberrantly activated in glioblastoma and has been identified as a relevant therapeutic target in this disease and many other human cancers. After two decades of intensive research, there is not yet any approved STAT3-based glioma therapy. In addition to the canonical activation by tyrosine 705 phosphorylation, concordant reports described a potential therapeutic relevance of other post-translational modifications including mainly serine 727 phosphorylation. Such reports reinforce the need to refine the strategy of targeting STAT3 in each concerned disease. This review focuses on the role of serine 727 and tyrosine 705 phosphorylation of STAT3 in glioma. It explores their contribution to glial cell transformation and to the mechanisms that make glioma escape to both immune control and standard treatment.
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Affiliation(s)
- Zangbéwendé Guy Ouédraogo
- Clermont Université, Université d'Auvergne, EA 7283, CREaT, BP 10448, F-63000, Clermont-Ferrand, France.,Département de Radiothérapie, Laboratoire de Radio-Oncologie Expérimentale, Centre Jean Perrin, EA7283 CREaT - Université d'Auvergne, 58 rue Montalembert, F-63000-63011, Clermont Ferrand, France.,Laboratoire de Pharmacologie, de Toxicologie et de Chimie Thérapeutique, Université de Ouagadougou, 03, Ouagadougou, BP 7021, Burkina Faso
| | - Julian Biau
- Clermont Université, Université d'Auvergne, EA 7283, CREaT, BP 10448, F-63000, Clermont-Ferrand, France.,Département de Radiothérapie, Laboratoire de Radio-Oncologie Expérimentale, Centre Jean Perrin, EA7283 CREaT - Université d'Auvergne, 58 rue Montalembert, F-63000-63011, Clermont Ferrand, France.,Département de Radiothérapie, Institut Curie, 91405, Orsay, France
| | - Jean-Louis Kemeny
- Clermont Université, Université d'Auvergne, EA 7283, CREaT, BP 10448, F-63000, Clermont-Ferrand, France.,CHU Clermont-Ferrand, Service d'Anatomopathologie, F-63003, Clermont-Ferrand, France
| | - Laurent Morel
- Clermont Université, Université Blaise-Pascal, GReD, UMR CNRS 6293, INSERM U1103, 24 Avenue des Landais BP80026, 63171, Aubière, France
| | - Pierre Verrelle
- Clermont Université, Université d'Auvergne, EA 7283, CREaT, BP 10448, F-63000, Clermont-Ferrand, France.,Département de Radiothérapie, Laboratoire de Radio-Oncologie Expérimentale, Centre Jean Perrin, EA7283 CREaT - Université d'Auvergne, 58 rue Montalembert, F-63000-63011, Clermont Ferrand, France.,Département de Radiothérapie, Institut Curie, 91405, Orsay, France
| | - Emmanuel Chautard
- Clermont Université, Université d'Auvergne, EA 7283, CREaT, BP 10448, F-63000, Clermont-Ferrand, France. .,Département de Radiothérapie, Laboratoire de Radio-Oncologie Expérimentale, Centre Jean Perrin, EA7283 CREaT - Université d'Auvergne, 58 rue Montalembert, F-63000-63011, Clermont Ferrand, France.
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10
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Xu Y, Goldkorn A. Telomere and Telomerase Therapeutics in Cancer. Genes (Basel) 2016; 7:genes7060022. [PMID: 27240403 PMCID: PMC4929421 DOI: 10.3390/genes7060022] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 05/18/2016] [Accepted: 05/20/2016] [Indexed: 12/13/2022] Open
Abstract
Telomerase is a reverse transcriptase capable of utilizing an integrated RNA component as a template to add protective tandem telomeric single strand DNA repeats, TTAGGG, to the ends of chromosomes. Telomere dysfunction and telomerase reactivation are observed in approximately 90% of human cancers; hence, telomerase activation plays a unique role as a nearly universal step on the path to malignancy. In the past two decades, multiple telomerase targeting therapeutic strategies have been pursued, including direct telomerase inhibition, telomerase interference, hTERT or hTERC promoter driven therapy, telomere-based approaches, and telomerase vaccines. Many of these strategies have entered clinical development, and some have now advanced to phase III clinical trials. In the coming years, one or more of these new telomerase-targeting drugs may be expected to enter the pharmacopeia of standard care. Here, we briefly review the molecular functions of telomerase in cancer and provide an update about the preclinical and clinical development of telomerase targeting therapeutics.
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Affiliation(s)
- Yucheng Xu
- Division of Medical Oncology, Department of Medicine, Keck School of Medicine and Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90033, USA.
| | - Amir Goldkorn
- Division of Medical Oncology, Department of Medicine, Keck School of Medicine and Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90033, USA.
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11
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Hormesis: Decoding Two Sides of the Same Coin. Pharmaceuticals (Basel) 2015; 8:865-83. [PMID: 26694419 PMCID: PMC4695814 DOI: 10.3390/ph8040865] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 12/09/2015] [Accepted: 12/11/2015] [Indexed: 12/13/2022] Open
Abstract
In the paradigm of drug administration, determining the correct dosage of a therapeutic is often a challenge. Several drugs have been noted to demonstrate contradictory effects per se at high and low doses. This duality in function of a drug at different concentrations is known as hormesis. Therefore, it becomes necessary to study these biphasic functions in order to understand the mechanistic basis of their effects. In this article, we focus on different molecules and pathways associated with diseases that possess a duality in their function and thus prove to be the seat of hormesis. In particular, we have highlighted the pathways and factors involved in the progression of cancer and how the biphasic behavior of the molecules involved can alter the manifestations of cancer. Because of the pragmatic role that it exhibits, the imminent need is to draw attention to the concept of hormesis. Herein, we also discuss different stressors that trigger hormesis and how stress-mediated responses increase the overall adaptive response of an individual to stress stimulus. We talk about common pathways through which cancer progresses (such as nuclear factor erythroid 2-related factor 2-Kelch-like ECH-associated protein 1 (Nrf2-Keap1), sirtuin-forkhead box O (SIRT-FOXO) and others), analyzing how diverse molecules associated with these pathways conform to hormesis.
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12
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Mohammad RM, Muqbil I, Lowe L, Yedjou C, Hsu HY, Lin LT, Siegelin MD, Fimognari C, Kumar NB, Dou QP, Yang H, Samadi AK, Russo GL, Spagnuolo C, Ray SK, Chakrabarti M, Morre JD, Coley HM, Honoki K, Fujii H, Georgakilas AG, Amedei A, Niccolai E, Amin A, Ashraf SS, Helferich WG, Yang X, Boosani CS, Guha G, Bhakta D, Ciriolo MR, Aquilano K, Chen S, Mohammed SI, Keith WN, Bilsland A, Halicka D, Nowsheen S, Azmi AS. Broad targeting of resistance to apoptosis in cancer. Semin Cancer Biol 2015; 35 Suppl:S78-S103. [PMID: 25936818 PMCID: PMC4720504 DOI: 10.1016/j.semcancer.2015.03.001] [Citation(s) in RCA: 527] [Impact Index Per Article: 58.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 03/04/2015] [Accepted: 03/04/2015] [Indexed: 12/15/2022]
Abstract
Apoptosis or programmed cell death is natural way of removing aged cells from the body. Most of the anti-cancer therapies trigger apoptosis induction and related cell death networks to eliminate malignant cells. However, in cancer, de-regulated apoptotic signaling, particularly the activation of an anti-apoptotic systems, allows cancer cells to escape this program leading to uncontrolled proliferation resulting in tumor survival, therapeutic resistance and recurrence of cancer. This resistance is a complicated phenomenon that emanates from the interactions of various molecules and signaling pathways. In this comprehensive review we discuss the various factors contributing to apoptosis resistance in cancers. The key resistance targets that are discussed include (1) Bcl-2 and Mcl-1 proteins; (2) autophagy processes; (3) necrosis and necroptosis; (4) heat shock protein signaling; (5) the proteasome pathway; (6) epigenetic mechanisms; and (7) aberrant nuclear export signaling. The shortcomings of current therapeutic modalities are highlighted and a broad spectrum strategy using approaches including (a) gossypol; (b) epigallocatechin-3-gallate; (c) UMI-77 (d) triptolide and (e) selinexor that can be used to overcome cell death resistance is presented. This review provides a roadmap for the design of successful anti-cancer strategies that overcome resistance to apoptosis for better therapeutic outcome in patients with cancer.
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Affiliation(s)
- Ramzi M Mohammad
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, United States; Interim translational Research Institute, Hamad Medical Corporation, Doha, Qatar.
| | - Irfana Muqbil
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, United States
| | - Leroy Lowe
- Getting to Know Cancer, Truro, Nova Scotia, Canada
| | - Clement Yedjou
- C-SET, [Jackson, #229] State University, Jackson, MS, United States
| | - Hsue-Yin Hsu
- Department of Life Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Liang-Tzung Lin
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Markus David Siegelin
- Department of Pathology and Cell Biology, Columbia University, New York City, NY, United States
| | - Carmela Fimognari
- Dipartimento di Scienze per la Qualità della Vita Alma Mater Studiorum-Università di Bologna, Italy
| | - Nagi B Kumar
- Moffit Cancer Center, University of South Florida College of Medicine, Tampa, FL, United States
| | - Q Ping Dou
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, United States; Departments of Pharmacology and Pathology, Karmanos Cancer Institute, Detroit MI, United States
| | - Huanjie Yang
- The School of Life Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | | | - Gian Luigi Russo
- Institute of Food Sciences National Research Council, Avellino, Italy
| | - Carmela Spagnuolo
- Institute of Food Sciences National Research Council, Avellino, Italy
| | - Swapan K Ray
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, SC, United States
| | - Mrinmay Chakrabarti
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, SC, United States
| | - James D Morre
- Mor-NuCo, Inc, Purdue Research Park, West Lafayette, IN, United States
| | - Helen M Coley
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, United Kingdom
| | - Kanya Honoki
- Department of Orthopedic Surgery, Nara Medical University, Kashihara, Japan
| | - Hiromasa Fujii
- Department of Orthopedic Surgery, Nara Medical University, Kashihara, Japan
| | - Alexandros G Georgakilas
- Department of Physics, School of Applied Mathematical and Physical Sciences, National Technical University of Athens, Zografou 15780, Athens, Greece
| | - Amedeo Amedei
- Department of Experimental and Clinical Medicine, university of florence, Italy
| | - Elena Niccolai
- Department of Experimental and Clinical Medicine, university of florence, Italy
| | - Amr Amin
- Department of Biology, College of Science, UAE University, United Arab Emirates; Faculty of Science, Cairo University, Egypt
| | - S Salman Ashraf
- Department of Chemistry, College of Science, UAE University, United Arab Emirates
| | - William G Helferich
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Xujuan Yang
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Chandra S Boosani
- Department of BioMedical Sciences, School of Medicine Creighton University, Omaha NE, United States
| | - Gunjan Guha
- School of Chemical and Bio Technology, SASTRA University, Thanjavur, India
| | - Dipita Bhakta
- School of Chemical and Bio Technology, SASTRA University, Thanjavur, India
| | | | - Katia Aquilano
- Department of Biology, University of Rome "Tor Vergata", Italy
| | - Sophie Chen
- Ovarian and Prostate Cancer Research Trust Laboratory, Guildford, Surrey, United Kingdom
| | - Sulma I Mohammed
- Department of Comparative Pathobiology and Purdue University Center for Cancer Research, Purdue, West Lafayette, IN, United States
| | - W Nicol Keith
- Institute of Cancer Sciences, University of Glasgow, Glasgow, Ireland
| | - Alan Bilsland
- Institute of Cancer Sciences, University of Glasgow, Glasgow, Ireland
| | - Dorota Halicka
- Department of Pathology, New York Medical College, Valhalla, NY, United States
| | - Somaira Nowsheen
- Mayo Graduate School, Mayo Medical School, Mayo Clinic Medical Scientist Training Program, Rochester, MN, United States
| | - Asfar S Azmi
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, United States
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13
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Exaggerated arsenic nephrotoxicity in female mice through estrogen-dependent impairments in the autophagic flux. Toxicology 2015; 339:9-18. [PMID: 26631322 DOI: 10.1016/j.tox.2015.11.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/23/2015] [Accepted: 11/23/2015] [Indexed: 11/22/2022]
Abstract
Gender is one of the essential factors in the development of various diseases and poisoning. Therefore, we herein examined gender differences in sodium arsenite (NaAsO2)-induced acute renal dysfunction. When male and female BALB/c mice were subcutaneously injected with NaAsO2 (12.5mg/kg), serum and urinary markers for proximal tubular injury were significantly higher in female mice than in male ones. NaAsO2-induced histopathological alterations were consistently more evident in females than in males. Ovariectomy, but not orchiectomy significantly attenuated NaAsO2-induced renal injury. These results imply that the hypersusceptibility of female mice is attributed to estrogen signals. NaAsO2 suppressed the autophagic flux in tubular cells through the activation of ERK. Enhancements in the activation of ERK were significantly greater in females than in males, with the eventual accumulation of LC3-II and P62 in the kidneys, implying that the autophagic flux is impaired in females. The IL-6/STAT3 signaling pathway had protective roles in NaAsO2-induced nephrotoxicity through the suppression of ERK activation. Despite the absence of differences in intrarenal IL-6 expression between male and female mice, STAT3 was less activated with enhanced SOCS3 expression in females than in males. An in vitro study using mProx24 cells revealed that the estrogen treatment induced SOCS3 expression, and eventually suppressed the autophagic flux, as evidenced by greater increases in the accumulation of LC3-II and p62 with ERK activation, which was canceled by the knockdown of Socs3. Collectively, these results indicate that estrogen has a negative impact on the development of NaAsO2 nephrotoxicity through its suppression of the autophagic flux.
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Zhang N, Bing T, Liu X, Qi C, Shen L, Wang L, Shangguan D. Cytotoxicity of guanine-based degradation products contributes to the antiproliferative activity of guanine-rich oligonucleotides. Chem Sci 2015; 6:3831-3838. [PMID: 29218153 PMCID: PMC5707456 DOI: 10.1039/c4sc03949a] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 04/04/2015] [Indexed: 01/03/2023] Open
Abstract
Guanine-rich oligonucleotides with lower nuclease resistance exhibited higher antiproliferative activity; guanine-based compounds showed highly concentration-dependent cytotoxicity.
Guanine-rich oligonucleotides (GROs) have attracted considerable attention as anticancer agents, because they exhibit cancer-selective antiproliferative activity and can form G-quadruplex structures with higher nuclease resistance and cellular uptake. Recently, a GRO, AS1411 has reached phase II clinical trials for acute myeloid leukemia and renal cell carcinoma. The antiproliferative activity of GROs has been associated with various protein targets; however the real mechanisms of action remain unclear. In this study, we showed evidence that antiproliferative activity of GROs (including AS1411) is mainly contributed by the cytotoxicity of their guanine-based degradation products, such as monophosphate deoxyguanosine (dGMP), deoxyguanosine (dG) and guanine. The GROs with lower nuclease resistance exhibited higher antiproliferative activity. Among nucleotides, nucleosides and nucleobases, only guanine-based compounds showed highly concentration-dependent cytotoxicity. Our results suggest that it is necessary to reconsider the cancer-selective antiproliferative activity of GROs. Since guanine-based compounds are endogenous substances in living organisms, systematic studies of the cytotoxicity of these compounds will provide new information for the understanding of certain diseases and offer useful information for drug design.
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Affiliation(s)
- Nan Zhang
- Beijing National Laboratory for Molecular Sciences , Key Laboratory of Analytical Chemistry for Living Biosystems , Institute of Chemistry , Chinese Academy of Sciences , Beijing , 100190 , China . ; ; Tel: +86-10-62528509.,University of the Chinese Academy of Sciences , Beijing 100049 , China
| | - Tao Bing
- Beijing National Laboratory for Molecular Sciences , Key Laboratory of Analytical Chemistry for Living Biosystems , Institute of Chemistry , Chinese Academy of Sciences , Beijing , 100190 , China . ; ; Tel: +86-10-62528509
| | - Xiangjun Liu
- Beijing National Laboratory for Molecular Sciences , Key Laboratory of Analytical Chemistry for Living Biosystems , Institute of Chemistry , Chinese Academy of Sciences , Beijing , 100190 , China . ; ; Tel: +86-10-62528509
| | - Cui Qi
- Beijing National Laboratory for Molecular Sciences , Key Laboratory of Analytical Chemistry for Living Biosystems , Institute of Chemistry , Chinese Academy of Sciences , Beijing , 100190 , China . ; ; Tel: +86-10-62528509
| | - Luyao Shen
- Beijing National Laboratory for Molecular Sciences , Key Laboratory of Analytical Chemistry for Living Biosystems , Institute of Chemistry , Chinese Academy of Sciences , Beijing , 100190 , China . ; ; Tel: +86-10-62528509.,University of the Chinese Academy of Sciences , Beijing 100049 , China
| | - Linlin Wang
- Beijing National Laboratory for Molecular Sciences , Key Laboratory of Analytical Chemistry for Living Biosystems , Institute of Chemistry , Chinese Academy of Sciences , Beijing , 100190 , China . ; ; Tel: +86-10-62528509
| | - Dihua Shangguan
- Beijing National Laboratory for Molecular Sciences , Key Laboratory of Analytical Chemistry for Living Biosystems , Institute of Chemistry , Chinese Academy of Sciences , Beijing , 100190 , China . ; ; Tel: +86-10-62528509
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15
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Mar FA, Debnath J, Stohr BA. Autophagy-independent senescence and genome instability driven by targeted telomere dysfunction. Autophagy 2015; 11:527-37. [PMID: 25751002 PMCID: PMC4502814 DOI: 10.1080/15548627.2015.1017189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 01/14/2015] [Accepted: 01/21/2015] [Indexed: 02/08/2023] Open
Abstract
Telomere dysfunction plays a complex role in tumorigenesis. While dysfunctional telomeres can block the proliferation of incipient cancer clones by inducing replicative senescence, fusion of dysfunctional telomeres can drive genome instability and oncogenic genomic rearrangements. Therefore, it is important to define the regulatory pathways that guide these opposing effects. Recent work has shown that the autophagy pathway regulates both senescence and genome instability in various contexts. Here, we apply models of acute telomere dysfunction to determine whether autophagy modulates the resulting genome instability and senescence responses. While telomere dysfunction rapidly induces autophagic flux in human fibroblast cell lines, inhibition of the autophagy pathway does not have a significant impact upon the transition to senescence, in contrast to what has previously been reported for oncogene-induced senescence. Our results suggest that this difference may be explained by disparities in the development of the senescence-associated secretory phenotype. We also show that chromosome fusions induced by telomere dysfunction are comparable in autophagy-proficient and autophagy-deficient cells. Altogether, our results highlight the complexity of the senescence-autophagy interface and indicate that autophagy induction is unlikely to play a significant role in telomere dysfunction-driven senescence and chromosome fusions.
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Key Words
- ACD/Tpp1, adrenocortical dysplasia homolog (mouse)
- ATG5, autophagy-related 5, ATG7, autophagy-related 7
- B2M, β-2-microglobulin
- HBSS, Hank's buffered salt solution
- HMECs, human mammary epithelial cells
- MEFs, mouse embryonic fibroblasts
- MT-HsTER, mutant template-Homo sapiens template-containing RNA
- MT-MmTER, mutant template-Mus musculus template-containing RNA
- OIS, oncogene-induced senescence
- RBBP8/CtIP, retinoblastoma binding protein 8
- SA-β-Gal, senescence-associated β-galactosidase
- SASP
- SASP, senescence associated secretory phenotype
- TDIS, telomere dysfunction-induced senescence
- TERT, telomerase reverse transcriptase
- TIFs, telomere dysfunction-induced foci
- autophagy
- chromosome fusions
- genome instability
- senescence
- telomerase
- telomeres
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Affiliation(s)
- Florie A Mar
- Biomedical Sciences Graduate Program; University of California San Francisco; San Francisco, CA USA
- Department of Pathology; University of California San Francisco; San Francisco, CA USA
| | - Jayanta Debnath
- Department of Pathology; University of California San Francisco; San Francisco, CA USA
- Helen Diller Family Comprehensive Cancer Center; University of California San Francisco; San Francisco, CA USA
| | - Bradley A Stohr
- Department of Pathology; University of California San Francisco; San Francisco, CA USA
- Helen Diller Family Comprehensive Cancer Center; University of California San Francisco; San Francisco, CA USA
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16
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Kaushik P, Molinelli EJ, Miller ML, Wang W, Korkut A, Liu W, Ju Z, Lu Y, Mills G, Sander C. Spatial normalization of reverse phase protein array data. PLoS One 2014; 9:e97213. [PMID: 25501559 PMCID: PMC4264691 DOI: 10.1371/journal.pone.0097213] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 02/11/2014] [Indexed: 11/17/2022] Open
Abstract
Reverse phase protein arrays (RPPA) are an efficient, high-throughput, cost-effective method for the quantification of specific proteins in complex biological samples. The quality of RPPA data may be affected by various sources of error. One of these, spatial variation, is caused by uneven exposure of different parts of an RPPA slide to the reagents used in protein detection. We present a method for the determination and correction of systematic spatial variation in RPPA slides using positive control spots printed on each slide. The method uses a simple bi-linear interpolation technique to obtain a surface representing the spatial variation occurring across the dimensions of a slide. This surface is used to calculate correction factors that can normalize the relative protein concentrations of the samples on each slide. The adoption of the method results in increased agreement between technical and biological replicates of various tumor and cell-line derived samples. Further, in data from a study of the melanoma cell-line SKMEL-133, several slides that had previously been rejected because they had a coefficient of variation (CV) greater than 15%, are rescued by reduction of CV below this threshold in each case. The method is implemented in the R statistical programing language. It is compatible with MicroVigene and SuperCurve, packages commonly used in RPPA data analysis. The method is made available, along with suggestions for implementation, at http://bitbucket.org/rppa_preprocess/rppa_preprocess/src.
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Affiliation(s)
- Poorvi Kaushik
- Computational Biology Center, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Evan J Molinelli
- Computational Biology Center, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Martin L Miller
- Computational Biology Center, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Weiqing Wang
- Computational Biology Center, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Anil Korkut
- Computational Biology Center, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Wenbin Liu
- Division of Quantitative Sciences, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Zhenlin Ju
- Division of Quantitative Sciences, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Yiling Lu
- Department of Systems Biology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Gordon Mills
- Department of Systems Biology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Chris Sander
- Computational Biology Center, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
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17
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Star-shaped tetraspermine enhances cellular uptake and cytotoxicity of T-oligo in prostate cancer cells. Pharm Res 2014; 32:196-210. [PMID: 25092067 DOI: 10.1007/s11095-014-1455-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 07/02/2014] [Indexed: 01/24/2023]
Abstract
PURPOSE An oligonucleotide termed 'T-oligo' having sequence homology with telomere overhang has shown cytotoxicity in multiple cancers. We have demonstrated that T-oligo can induce apoptosis in androgen independent prostate cancer cell line DU-145. In this report, we evaluate the use of star-shaped tetraspermine (SSTS) for delivery of T-oligo. METHODS SSTS was synthesized from spermine and its intrinsic cytotoxicity towards DU-145 cells was compared with spermine and branched polyethyleneimine (bPEI). Atomistic molecular dynamic (MD) simulations were conducted to understand binding and complexation of spermine and SSTS with T-oligo. Complexation was also determined using gel electrophoresis and SYBR gold assay. Complexes were characterized for size, cellular uptake and antiproliferative effect. RESULTS SSTS exhibited significantly lower toxicity than spermine and bPEI. Its affinity towards T-oligo was significantly higher than spermine as determined by experimental studies and confirmed by MD simulations and it formed stable complexes (TONPs) with T-oligo. TONPs facilitated cellular uptake and nuclear accumulation of T-oligo and their cytotoxic potential was observed at concentration several folds lower than that required for T-oligo alone. CONCLUSION SSTS significantly enhanced therapeutic benefits associated with the use of T-oligo and can be developed as a delivery vehicle for its in-vivo therapeutic applications.
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18
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Targeted inhibition of mTOR signaling improves sensitivity of esophageal squamous cell carcinoma cells to cisplatin. J Immunol Res 2014; 2014:845763. [PMID: 24818169 PMCID: PMC4003759 DOI: 10.1155/2014/845763] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 03/27/2014] [Indexed: 11/22/2022] Open
Abstract
mTOR is an evolutionarily conserved serine-threonine kinase with a central role in cell growth, invasion, and metastasis of tumors, and is activated in many cancers. The aims of this study were to investigate the expression of mTOR in ESCC tissues and its relationship with progression of ESCC and measure the changes of sensitivity of ESCC cells to cisplatin after cells were treated with mTOR siRNA by WST-8 assays, TUNEL, RT-PCR, and western blots in vitro and in vivo. The results showed that the expression of mTOR was higher in ESCC specimens than that in normal esophageal tissues and its expression was closely correlated with the TNM stage of ESCC. mTOR siRNA significantly increased the sensitivity of the EC9706 cells to cisplatin at proliferation in vitro and in vivo. The growth of ESCC xenografts was significantly inhibited by mTOR siRNA or cisplatin, and the cell number of apoptosis was obviously increased after xenografts were treated with mTOR siRNA or cisplatin alone, especially when mTOR siRNA combined with cisplatin. The present study demonstrates that the expression of mTOR has important clinical significance and inhibition of mTOR pathway by mTOR siRNA can improve the sensitivity of ESCC cells to cisplatin.
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19
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T-oligo as an anticancer agent in colorectal cancer. Biochem Biophys Res Commun 2014; 446:596-601. [PMID: 24632202 DOI: 10.1016/j.bbrc.2014.03.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 03/04/2014] [Indexed: 11/22/2022]
Abstract
In the United States, there will be an estimated 96,830 new cases of colorectal cancer (CRC) and 50,310 deaths in 2014. CRC is often detected at late stages of the disease, at which point there is no effective chemotherapy. Thus, there is an urgent need for effective novel therapies that have minimal effects on normal cells. T-oligo, an oligonucleotide homologous to the 3'-telomere overhang, induces potent DNA damage responses in multiple malignant cell types, however, its efficacy in CRC has not been studied. This is the first investigation demonstrating T-oligo-induced anticancer effects in two CRC cell lines, HT-29 and LoVo, which are highly resistant to conventional chemotherapies. In this investigation, we show that T-oligo may mediate its DNA damage responses through the p53/p73 pathway, thereby inhibiting cellular proliferation and inducing apoptosis or senescence. Additionally, upregulation of downstream DNA damage response proteins, including E2F1, p53 or p73, was observed. In LoVo cells, T-oligo induced senescence, decreased clonogenicity, and increased expression of senescence associated proteins p21, p27, and p53. In addition, downregulation of POT1 and TRF2, two components of the shelterin protein complex which protects telomeric ends, was observed. Moreover, we studied the antiproliferative effects of T-oligo in combination with an EGFR tyrosine kinase inhibitor, Gefitinib, which resulted in an additive inhibitory effect on cellular proliferation. Collectively, these data provide evidence that T-oligo alone, or in combination with other molecularly targeted therapies, has potential as an anti-cancer agent in CRC.
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20
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Fadri-Moskwik M, Zhou Q, Chai W. Beyond Telomerase: Telomere Instability as a Novel Target for Cancer Therapy. J Mol Genet Med 2013; 7. [PMID: 27123041 PMCID: PMC4844356 DOI: 10.4172/1747-0862.1000091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Telomeres are areas of heterochromatin composed of TTAGGG repeats located at the ends of linear chromosomes. They play a critical role in keeping genome stable and preventing premature aging diseases and the development of cancer. Characterizing mechanisms of telomere maintenance and understanding how their deregulation contributes to human diseases are therefore important for developing novel therapies. A key mechanism driving telomere maintenance and replicative immortality in cancer cells is telomere elongation by telomerase, and many emerging potential telomere-based therapies have focused on targeting telomerase components. By contrast, recent studies on telomere maintenance mechanism suggest that disrupting telomere stability by interfering with alternative mechanisms of telomere synthesis or protection may also yield new strategies for the treatment of cancer. This review will focus on emerging regulators of telomere synthesis or maintenance, such as G4 telomeric DNA, the CST complex, the t-loop, and shelterins, and discuss their potential as targets for anti-cancer chemotherapeutic intervention in the future.
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Affiliation(s)
- Maria Fadri-Moskwik
- Section of Medical Sciences and School of Molecular Biosciences, Washington State University, USA
| | - Qing Zhou
- Section of Medical Sciences and School of Molecular Biosciences, Washington State University, USA
| | - Weihang Chai
- Section of Medical Sciences and School of Molecular Biosciences, Washington State University, USA
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21
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Puri N, Pitman RT, Mulnix RE, Erickson T, Iness AN, Vitali C, Zhao Y, Salgia R. Non-small cell lung cancer is susceptible to induction of DNA damage responses and inhibition of angiogenesis by telomere overhang oligonucleotides. Cancer Lett 2013; 343:14-23. [PMID: 24041868 DOI: 10.1016/j.canlet.2013.09.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 08/15/2013] [Accepted: 09/08/2013] [Indexed: 10/26/2022]
Abstract
Exposure of the telomere overhang acts as a DNA damage signal, and exogenous administration of an 11-base oligonucleotide homologous to the 3'-telomere overhang sequence (T-oligo) mimics the effects of overhang exposure by inducing senescence and cell death in non-small cell lung cancer (NSCLC) cells, but not in normal bronchial epithelial cells. T-oligo-induced decrease in cellular proliferation in NSCLC is likely directed through both p53 and its homolog, p73, with subsequent induction of senescence and expression of senescence-associated proteins, p21, p33(ING), and p27(Kip1) both in vivo and in vitro. Additionally, T-oligo decreases tumor size and inhibits angiogenesis through decreased VEGF signaling and increased TSP-1 expression.
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Affiliation(s)
- Neelu Puri
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, IL, United States.
| | - Ryan T Pitman
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, IL, United States
| | - Richard E Mulnix
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, IL, United States
| | - Terrianne Erickson
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, IL, United States
| | - Audra N Iness
- Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford, IL, United States
| | - Connie Vitali
- Department of Pathology, University of Illinois College of Medicine, Rockford, IL, United States
| | - Yutong Zhao
- Department of Medicine, Division of Pulmonary, Allergy, Critical Care, University of Pittsburgh, Pittsburgh, PA, United States
| | - Ravi Salgia
- Department of Medicine, Section of Hematology/Oncology, University of Chicago, Chicago, IL, United States
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22
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Rankin AM, Forman L, Sarkar S, Faller DV. Enhanced cytotoxicity from deoxyguanosine-enriched T-oligo in prostate cancer cells. Nucleic Acid Ther 2013; 23:311-21. [PMID: 23971906 DOI: 10.1089/nat.2013.0420] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Prostate cancer represents approximately 10 percent of all cancer cases in men and accounts for more than a quarter of all cancer types. Advances in understanding the molecular mechanisms of prostate cancer progression, however, have not translated well to the clinic. Patients with metastatic and hormone-refractory disease have only palliative options for treatment, as chemotherapy seldom produces durable or complete responses, highlighting the need for novel therapeutic approaches. T-oligo, a single-stranded deoxyribonucleic acid with partial sequence homology to human telomeric DNA, has elicited cytostatic and/or cytotoxic effects in multiple cancer cell types. In contrast, normal primary cells of varying tissue types are resistant to cytotoxic actions of T-oligo, underscoring its potential utility as a novel targeted cancer therapeutic. Mechanistically, T-oligo is hypothesized to interfere with normal telomeric structure and form G-quadruplex structures, thereby inducing genomic stress in addition to aberrant upregulation of DNA damageresponse pathways. Here, we present data demonstrating the enhanced effectiveness of a deoxyguanosine-enriched sequence of T-oligo, termed (GGTT)4, which elicits robust cytotoxic effects in prostate cancer cells at lower concentrations than the most recent T-oligo sequence (5'-pGGT TAG GTG TAG GTT T 3') described to date and used for comparison in this study, while exerting no cytotoxic actions on nontransformed human prostate epithelial cells. Additionally, we provide evidence supporting the T-oligo induced activation of cJun N-terminal kinase (JNK) signaling in prostate cancer cells consistent with G-quadruplex formation, thereby significantly advancing the understanding of the T-oligo mechanism of action.
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Affiliation(s)
- Andrew M Rankin
- Cancer Center and Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, USA
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23
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Das Gupta S, Halder B, Gomes A, Gomes A. Bengalin initiates autophagic cell death through ERK–MAPK pathway following suppression of apoptosis in human leukemic U937 cells. Life Sci 2013; 93:271-6. [DOI: 10.1016/j.lfs.2013.06.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 05/29/2013] [Accepted: 06/24/2013] [Indexed: 12/16/2022]
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Orlotti NI, Cimino-Reale G, Borghini E, Pennati M, Sissi C, Perrone F, Palumbo M, Daidone MG, Folini M, Zaffaroni N. Autophagy acts as a safeguard mechanism against G-quadruplex ligand-mediated DNA damage. Autophagy 2012; 8:1185-96. [PMID: 22627293 DOI: 10.4161/auto.20519] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
G-quadruplex ligands have attracted considerable interest as novel anticancer therapeutics due to their capability to interfere with guanosine-rich DNA/RNA sequences, such as telomeres. Elucidation of the structures of telomeric G-quadruplexes has led, in the past few years, to the rational development of effective G-quadruplex-stabilizing small molecules. In the present study, we showed that short-term exposure of melanoma cells to Ant1,5--an anthracene-based ligand able to stabilize telomeric G-quadruplexes--impaired cell growth without inducing cell senescence or apoptosis. Conversely, drug-treated cells were characterized by the occurrence of typical biochemical and morphological features associated with autophagy, such as an increase in the lipidated form of the autophagic marker LC3B and the accumulation of autophagosomes. Such drug-induced autophagy occurred as a consequence of DNA damage induction, at least in part dependent on drug-mediated telomere uncapping, through a pathway converging on the cyclin-dependent kinase inhibitor 1A (CDKN1A/p21). Indeed, melanoma cells depleted for CDKN1A did not show evidence of autophagic markers upon exposure to Ant1,5. The inhibition of autophagy by a pharmacologic inhibitor or through RNAi-mediated depletion of the ATG5 gene enhanced the cytotoxic activity of Ant1,5, as revealed by the marked increase in drug-induced apoptosis. Our data outline a molecular scenario in which G-quadruplex ligand-induced telomeric dysfunctions and DNA damage are translated into an autophagic response and provide the first evidence of autophagy as a safeguard mechanism activated by melanoma cells to counteract G-quadruplex ligand-mediated cellular stress.
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Affiliation(s)
- Nicola Ivan Orlotti
- Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
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25
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Rankin AM, Sarkar S, Faller DV. Mechanism of T-oligo-induced cell cycle arrest in Mia-PaCa pancreatic cancer cells. J Cell Physiol 2012; 227:2586-94. [PMID: 21898405 DOI: 10.1002/jcp.22997] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
DNA oligonucleotides with sequence homology to human telomeric DNA (T-oligo) induce cell cycle arrest, followed by apoptosis, senescence, or autophagy in a human cancer cell type-specific manner. T-oligo has potential as a new therapeutic strategy in oncology because of its ability to target certain types of tumor cells while sparing normal ones. In the present study, we demonstrate the T-oligo-induced S-phase cell cycle arrest in four pancreatic cancer cell lines. To further contribute to the mechanistic understanding of T-oligo, we also identify cyclin dependent kinase 2 (cdk2) as a functional mediator in the T-oligo-induced cell cycle arrest of pancreatic cancer cells. Ectopic expression of a constitutively active cdk2 mutant abrogates T-oligo-induced cell cycle arrest in these tumor cells while knockdown of cdk2 expression alone recapitulates the T-oligo effect. Finally, we demonstrate the dispensability of T-oligo-induced ATM/ATR-mediated DNA damage response-signaling pathways, which have long been considered functional in the T-oligo signaling mechanism.
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Affiliation(s)
- Andrew M Rankin
- Cancer Center, Boston University School of Medicine, Boston, Massachusetts 02118-2307, USA
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Ambroz K. Impact of blocking and detection chemistries on antibody performance for reverse phase protein arrays. Methods Mol Biol 2012; 785:13-21. [PMID: 21901590 DOI: 10.1007/978-1-61779-286-1_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Careful selection of well-qualified antibodies is critical for accurate data collection from reverse phase protein arrays (RPPA). The most common way to qualify antibodies for RPPA analysis is by Western blotting because the detection mechanism is based on the same immunodetection principles. Western blots of tissue or cell lysates that result in single bands and low cross-reactivity indicate appropriate antibodies for RPPA detection. Western blot conditions used to validate antibodies for RPPA experiments, including blocking and detection reagents, have significant effects on aspects of antibody performance such as cross-reactivity against other proteins in the sample. We have found that there can be a dramatic impact on antibody behavior with changes in blocking reagent and detection method, and offer an alternative method that allows detection reagents and conditions to be held constant in both antibody validation and RPPA experiments.
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Affiliation(s)
- Kristi Ambroz
- Biotechnology Reagent Operations and Technical Support, LI-COR, Lincoln, NE, USA.
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Single-cell proteomic chip for profiling intracellular signaling pathways in single tumor cells. Proc Natl Acad Sci U S A 2011; 109:419-24. [PMID: 22203961 DOI: 10.1073/pnas.1110865109] [Citation(s) in RCA: 252] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We describe a microchip designed to quantify the levels of a dozen cytoplasmic and membrane proteins from single cells. We use the platform to assess protein-protein interactions associated with the EGF-receptor-mediated PI3K signaling pathway. Single-cell sensitivity is achieved by isolating a defined number of cells (n = 0-5) in 2 nL volume chambers, each of which is patterned with two copies of a miniature antibody array. The cells are lysed on-chip, and the levels of released proteins are assayed using the antibody arrays. We investigate three isogenic cell lines representing the cancer glioblastoma multiforme, at the basal level, under EGF stimulation, and under erlotinib inhibition plus EGF stimulation. The measured protein abundances are consistent with previous work, and single-cell analysis uniquely reveals single-cell heterogeneity, and different types and strengths of protein-protein interactions. This platform helps provide a comprehensive picture of altered signal transduction networks in tumor cells and provides insight into the effect of targeted therapies on protein signaling networks.
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Cox LS, Mason PA. Prospects for rejuvenation of aged tissue by telomerase reactivation. Rejuvenation Res 2011; 13:749-54. [PMID: 21226558 DOI: 10.1089/rej.2010.1140] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Human aging is associated with loss of tissue homeostasis and a greatly elevated risk of debilitating disease, with associated costs in terms of diminished quality of life for the individual and financial burdens on health-care providers. Any advances that hold out the realistic prospect of tackling age-related morbidity are therefore to be welcomed. The recent report by Jeskelioff et al. published in 2010 that telomerase reactivation in adult male mice can not only halt but actually reverse significant tissue pathologies provides a long-awaited proof of principle that it is possible to rejuvenate aged tissues. This review assesses the impact of this new work and considers possible problems and potential benefits of telomerase activation as a therapy to tackle the morbidities associated with human aging.
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Affiliation(s)
- Lynne S Cox
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
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Sarkar S, Faller DV. T-oligos inhibit growth and induce apoptosis in human ovarian cancer cells. Oligonucleotides 2011; 21:47-53. [PMID: 21281128 DOI: 10.1089/oli.2010.0259] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Ovarian cancer remains a leading cause of death among women worldwide, and current treatment regimens for advanced disease are inadequate. Oligonucleotides with sequence homology to telomeres (called T-oligos) have been shown to mimic DNA damage responses in cells and induce cytotoxic effects in certain tumor cell lines. We studied the effects of 2 distinct 16 mer T-oligos in 4 human ovarian epithelial carcinoma cell lines. A T-oligo with perfect homology to the telomere overhang region demonstrated some cytotoxic activity in half of the cell lines. A G-rich T-oligo derivative showed more potency and broader cytotoxic activity in these lines than the parental T-oligo. Activation of apoptotic pathways in ovarian cancer cells by exposure to the T-oligo was demonstrated by multiple independent assays. T-oligo was shown to have additive, or more than additive, activity in combination with 2 different histone deacetylase drugs currently in clinical testing. T-oligos may therefore provide a new and tumor-targeted approach to ovarian cancers.
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Affiliation(s)
- Sibaji Sarkar
- Cancer Center, Boston University School of Medicine, Boston, Massachusetts, USA
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Mueller C, Liotta LA, Espina V. Reverse phase protein microarrays advance to use in clinical trials. Mol Oncol 2010; 4:461-81. [PMID: 20974554 PMCID: PMC2981612 DOI: 10.1016/j.molonc.2010.09.003] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Revised: 09/15/2010] [Accepted: 09/16/2010] [Indexed: 12/18/2022] Open
Abstract
Individualizing cancer therapy for molecular targeted inhibitors requires a new class of molecular profiling technology that can map the functional state of the cancer cell signal pathways containing the drug targets. Reverse phase protein microarrays (RPMA) are a technology platform designed for quantitative, multiplexed analysis of specific phosphorylated, cleaved, or total (phosphorylated and non-phosphorylated) forms of cellular proteins from a limited amount of sample. This class of microarray can be used to interrogate tissue samples, cells, serum, or body fluids. RPMA were previously a research tool; now this technology has graduated to use in research clinical trials with clinical grade sensitivity and precision. In this review we describe the application of RPMA for multiplexed signal pathway analysis in therapeutic monitoring, biomarker discovery, and evaluation of pharmaceutical targets, and conclude with a summary of the technical aspects of RPMA construction and analysis.
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Affiliation(s)
- Claudius Mueller
- George Mason University, Center for Applied Proteomics and Molecular Medicine, Manassas, VA 20110, USA
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Radiosensitization of mammary carcinoma cells by telomere homolog oligonucleotide pretreatment. Breast Cancer Res 2010; 12:R71. [PMID: 20846433 PMCID: PMC3096958 DOI: 10.1186/bcr2639] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2010] [Accepted: 09/16/2010] [Indexed: 12/31/2022] Open
Abstract
Introduction Ionizing radiation (IR) is a widely used approach to cancer therapy, ranking second only to surgery in rate of utilization. Responses of cancer patients to radiotherapy depend in part on the intrinsic radiosensitivity of the tumor cells. Thus, promoting tumor cell sensitivity to IR could significantly enhance the treatment outcome and quality of life for patients. Methods Mammary tumor cells were treated by a 16-base phosphodiester-linked oligonucleotide homologous to the telomere G-rich sequence TTAGGG (T-oligo: GGTTAGGTGTAGGTTT) or a control-oligo (the partial complement, TAACCCTAACCCTAAC) followed by IR. The inhibition of tumor cell growth in vitro was assessed by cell counting and clonogenic cell survival assay. The tumorigenesis of tumor cells after various treatments was measured by tumor growth in mice. The mechanism underlying the radiosensitization by T-oligo was explored by immunofluorescent determination of phosphorylated histone H2AX (γH2AX) foci, β-galactosidase staining, comet and Terminal deoxynucleotidyl transferase dUTP Nick End Labeling (TUNEL) assays. The efficacy of the combined treatment was assessed in a spontaneous murine mammary tumor model. Results Pretreatment of tumor cells with T-oligo for 24 hours in vitro enhanced both senescence and apoptosis of irradiated tumor cells and reduced clonogenic potential. Radiosensitization by T-oligo was associated with increased formation and/or delayed resolution of γH2AX DNA damage foci and fragmented DNA. T-oligo also caused radiosensitization in two in vivo mammary tumor models. Indeed, combined T-oligo and IR-treatment in vivo led to a substantial reduction in tumor growth. Of further significance, treatment with T-oligo and IR led to synergistic inhibition of the growth of spontaneous mammary carcinomas. Despite these profound antitumor properties, T-oligo and IR caused no detectable side effects under our experimental conditions. Conclusions Pretreatment with T-oligo sensitizes mammary tumor cells to radiation in both in vitro and in vivo settings with minimal or no normal tissue side effects.
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Van Grol J, Subauste C, Andrade RM, Fujinaga K, Nelson J, Subauste CS. HIV-1 inhibits autophagy in bystander macrophage/monocytic cells through Src-Akt and STAT3. PLoS One 2010; 5:e11733. [PMID: 20661303 PMCID: PMC2908694 DOI: 10.1371/journal.pone.0011733] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Accepted: 06/16/2010] [Indexed: 11/18/2022] Open
Abstract
Autophagy is a homeostatic mechanism of lysosomal degradation. Defective autophagy has been linked to various disorders such as impaired control of pathogens and neurodegeneration. Autophagy is regulated by a complex array of signaling pathways that act upstream of autophagy proteins. Little is known about the role of altered regulatory signaling in disorders associated with defective autophagy. In particular, it is not known if pathogens inhibit autophagy by modulation of upstream regulatory pathways. Cells infected with HIV-1 blocked rapamycin-induced autophagy and CD40-induced autophagic killing of Toxoplasma gondii in bystander (non-HIV-1 infected) macrophage/monocytic cells. Blockade of autophagy was dependent on Src-Akt and STAT3 triggered by HIV-1 Tat and IL-10. Neutralization of the upstream receptors VEGFR, beta-integrin or CXCR4, as well as of HIV-1 Tat or IL-10 restored autophagy in macrophage/monocytic cells exposed to HIV-1-infected cells. Defective autophagic killing of T. gondii was detected in monocyte-derived macrophages from a subset of HIV-1(+) patients. This defect was also reverted by neutralization of Tat or IL-10. These studies revealed that a pathogen can impair autophagy in non-infected cells by activating counter-regulatory pathways. The fact that pharmacologic manipulation of cell signaling restored autophagy in cells exposed to HIV-1-infected cells raises the possibility of therapeutic manipulation of cell signaling to restore autophagy in HIV-1 infection.
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Affiliation(s)
- Jennifer Van Grol
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Cecilia Subauste
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Rosa M. Andrade
- Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
| | - Koh Fujinaga
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Julie Nelson
- Center for AIDS Research, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Carlos S. Subauste
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- * E-mail:
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Inhibition of melanoma angiogenesis by telomere homolog oligonucleotides. JOURNAL OF ONCOLOGY 2010; 2010:928628. [PMID: 20652008 PMCID: PMC2906154 DOI: 10.1155/2010/928628] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 05/06/2010] [Accepted: 05/07/2010] [Indexed: 01/13/2023]
Abstract
Telomere homolog oligonucleotides (T-oligos) activate an innate telomere-based program that leads to multiple anticancer effects. T-oligos act at telomeres to initiate signaling through the Werner protein and ATM kinase. We wanted to determine if T-oligos have antiangiogenic effects. We found that T-oligo-treated human melanoma (MM-AN) cells had decreased expression of vascular endothelial growth factor (VEGF), VEGF receptor 2, angiopoeitin-1 and -2 and decreased VEGF secretion. T-oligos activated the transcription factor E2F1 and inhibited the activity of the angiogenic transcription factor, HIF-1α. T-oligos inhibited EC tubulogenesis and total tumor microvascular density matrix invasion by MM-AN cells and ECs in vitro. In melanoma SCID xenografts, two systemic T-oligo injections decreased by 60% (P < .004) total tumor microvascular density and the functional vessels density by 80% (P < .002). These findings suggest that restriction of tumor angiogenesis is among the host's innate telomere-based anticancer responses and provide further evidence that T-oligos may offer a powerful new approach for melanoma treatment.
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Brase JC, Mannsperger H, Fröhlich H, Gade S, Schmidt C, Wiemann S, Beissbarth T, Schlomm T, Sültmann H, Korf U. Increasing the sensitivity of reverse phase protein arrays by antibody-mediated signal amplification. Proteome Sci 2010; 8:36. [PMID: 20569466 PMCID: PMC2908584 DOI: 10.1186/1477-5956-8-36] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 06/22/2010] [Indexed: 11/24/2022] Open
Abstract
Background Reverse phase protein arrays (RPPA) emerged as a useful experimental platform to analyze biological samples in a high-throughput format. Different signal detection methods have been described to generate a quantitative readout on RPPA including the use of fluorescently labeled antibodies. Increasing the sensitivity of RPPA approaches is important since many signaling proteins or posttranslational modifications are present at a low level. Results A new antibody-mediated signal amplification (AMSA) strategy relying on sequential incubation steps with fluorescently-labeled secondary antibodies reactive against each other is introduced here. The signal quantification is performed in the near-infrared range. The RPPA-based analysis of 14 endogenous proteins in seven different cell lines demonstrated a strong correlation (r = 0.89) between AMSA and standard NIR detection. Probing serial dilutions of human cancer cell lines with different primary antibodies demonstrated that the new amplification approach improved the limit of detection especially for low abundant target proteins. Conclusions Antibody-mediated signal amplification is a convenient and cost-effective approach for the robust and specific quantification of low abundant proteins on RPPAs. Contrasting other amplification approaches it allows target protein detection over a large linear range.
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Affiliation(s)
- Jan C Brase
- Division of Molecular Genome Analysis, German Cancer Research Center, Heidelberg, Germany.
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Abstract
Mimetics of hormetic agents offer a novel approach to adjust dose to minimize the risk of toxic response, and maximize the benefit of induction of at least partial physiological conditioning. Nature selected and preserved those organisms and triggers that promote tolerance to stress. The induced tolerance can serve to resist that challenge and can repair previous age, disease, and trauma damage as well to provide a more youthful response to other stresses. The associated physiological conditioning may include youthful restoration of DNA repair, resistance to oxidizing pollutants, protein structure and function repair, improved immunity, tissue remodeling, adjustments in central and peripheral nervous systems, and altered metabolism. By elucidating common pathways activated by hormetic agent's mimetics, new strategies for intervention in aging, disease, and trauma emerge. Intervention potential in cancer, diabetes, age-related diseases, infectious diseases, cardiovascular diseases, and Alzheimer's disease are possible. Some hormetic mimetics exist in pathways in primitive organisms and are active or latent in humans. Peptides, oligonucleotides, and hormones are among the mimetics that activate latent resistance to radiation, physical endurance, strength, and immunity to physiological condition tolerance to stress. Co-activators may be required for expression of the desired physiological conditioning health and rejuvenation benefits.
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Affiliation(s)
- Joan Smith Sonneborn
- Department of Zoology and Physiology, University of Wyoming, 1000 E. University Avenue, Laramie, WY 82071, USA
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36
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Kimura A, Ishida Y, Wada T, Hisaoka T, Morikawa Y, Sugaya T, Mukaida N, Kondo T. The absence of interleukin-6 enhanced arsenite-induced renal injury by promoting autophagy of tubular epithelial cells with aberrant extracellular signal-regulated kinase activation. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 176:40-50. [PMID: 20008137 DOI: 10.2353/ajpath.2010.090146] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Sodium arsenite (NaAs)-induced autophagic cell death (ACD) of a mouse renal tubular epithelial cell line (mProx24), which expresses enhanced levels of interleukin-6 (IL-6), was reduced by the suppression of autophagy by 3-methyladenine or Atg7 knockdown. The inhibition of the IL-6/signal transducer and activator of transcription 3 (STAT3) signal pathway by anti-IL-6 antibody or a Jak2 inhibitor (AG490) exaggerated ACD of mProx24 cells after NaAs challenge, attenuating STAT3 activation and reciprocally enhancing extracellular signal-regulated kinase (ERK) phosphorylation. In contrast, an ERK inhibitor, PD98059, reduced NaAs-induced ACD in mProx24 cells. Subcutaneous injection of NaAs (12.5 mg/kg) into BALB/c (wild-type) mice enhanced intrarenal expression of IL-6, mainly produced by tubular cells, and caused severe renal injury characterized by hemorrhages, acute tubular necrosis, cast formation, and brush border disappearance, with increases in serum urea nitrogen (blood urea nitrogen) and creatinine levels. In addition, IL-6-deficient (IL-6(-/-)) mice exhibited exaggerated histopathological changes with higher blood urea nitrogen and creatinine levels. Moreover, in IL-6(-/-) mice treated with NaAs, ACD in renal tubular cells was significantly augmented, along with diminished STAT3 activation and reciprocal enhancement of ERK signaling, compared with wild-type mice. Finally, the administration of exogenous IL-6 into wild-type mice significantly reduced NaAs-induced ACD along with diminished ERK activation and eventually alleviated acute renal dysfunction. Thus, IL-6/STAT3 signal pathway could inhibit ERK activation, a crucial step for ACD, eventually attenuating NaAs-induced renal dysfunction.
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Affiliation(s)
- Akihiko Kimura
- Department of Forensic Medicine, Wakayama Medical University, Wakayama 641-8509, Japan
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Gnanasekar M, Thirugnanam S, Zheng G, Chen A, Ramaswamy K. T-oligo induces apoptosis in advanced prostate cancer cells. Oligonucleotides 2009; 19:287-92. [PMID: 19642913 DOI: 10.1089/oli.2009.0179] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Prostate cancer is the most frequently diagnosed malignancy in men. As cancer progresses from an androgen-sensitive stage to hormone-refractory stage, it turns resistant to androgen ablation therapy. At this stage, effective newer therapies that induce apoptosis are needed for treatment of prostate cancer. DNA oligonucleotides homologous to the telomere 3' overhang (T-oligo) induce apoptosis in several human cancer cells. In the present study, we studied the effect of T-oligo on prostate cancer cells. Our studies showed that androgen-independent DU-145 cells are sensitive to T-oligo in terms of inhibition of proliferation. Moreover, T-oligo induced DU-145 cells to undergo apoptosis. Therefore, our results are encouraging for further investigation in the potential application of T-oligo as a novel therapeutic approach for prostate cancer, especially the androgen-independent.
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Affiliation(s)
- Munirathinam Gnanasekar
- Department of Biomedical Sciences, University of Illinois, College of Medicine, 1601 Parkview Avenue, Rockford, IL 61107, USA.
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Abstract
UV-induced melanogenesis (tanning) and "premature aging" or photoaging result in large part from DNA damage. This article reviews data tying both phenomena to telomere-based DNA damage signaling and develops a conceptual framework in which both responses may be understood as cancer-avoidance protective mechanisms.Journal of Investigative Dermatology Symposium Proceedings (2009) 14, 25-31; doi:10.1038/jidsymp.2009.9.
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The telomerase template antagonist GRN163L alters MDA-MB-231 breast cancer cell morphology, inhibits growth, and augments the effects of paclitaxel. Mol Cancer Ther 2009; 8:2027-35. [DOI: 10.1158/1535-7163.mct-08-1188] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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40
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Bates PJ, Laber DA, Miller DM, Thomas SD, Trent JO. Discovery and development of the G-rich oligonucleotide AS1411 as a novel treatment for cancer. Exp Mol Pathol 2009; 86:151-64. [PMID: 19454272 PMCID: PMC2716701 DOI: 10.1016/j.yexmp.2009.01.004] [Citation(s) in RCA: 593] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Indexed: 02/07/2023]
Abstract
Certain guanine-rich (G-rich) DNA and RNA molecules can associate intermolecularly or intramolecularly to form four stranded or "quadruplex" structures, which have unusual biophysical and biological properties. Several synthetic G-rich quadruplex-forming oligodeoxynucleotides have recently been investigated as therapeutic agents for various human diseases. We refer to these biologically active G-rich oligonucleotides as aptamers because their activities arise from binding to protein targets via shape-specific recognition (analogous to antibody-antigen binding). As therapeutic agents, the G-rich aptamers may have some advantages over monoclonal antibodies and other oligonucleotide-based approaches. For example, quadruplex oligonucleotides are non-immunogenic, heat stable and they have increased resistance to serum nucleases and enhanced cellular uptake compared to unstructured sequences. In this review, we describe the characteristics and activities of G-rich oligonucleotides. We also give a personal perspective on the discovery and development of AS1411, an antiproliferative G-rich phosphodiester oligonucleotide that is currently being tested as an anticancer agent in Phase II clinical trials. This molecule functions as an aptamer to nucleolin, a multifunctional protein that is highly expressed by cancer cells, both intracellularly and on the cell surface. Thus, the serendipitous discovery of the G-rich oligonucleotides also led to the identification of nucleolin as a new molecular target for cancer therapy.
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Affiliation(s)
- Paula J Bates
- James Graham Brown Cancer Center, Department of Medicine, University of Louisville, Louisville, Kentucky 40202, USA.
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Zhang L, Wei Q, Mao L, Liu W, Mills GB, Coombes K. Serial dilution curve: a new method for analysis of reverse phase protein array data. Bioinformatics 2009; 25:650-4. [PMID: 19176552 PMCID: PMC2647837 DOI: 10.1093/bioinformatics/btn663] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
UNLABELLED Reverse phase protein arrays (RPPAs) are a powerful high-throughput tool for measuring protein concentrations in a large number of samples. In RPPA technology, the original samples are often diluted successively multiple times, forming dilution series to extend the dynamic range of the measurements and to increase confidence in quantitation. An RPPA experiment is equivalent to running multiple ELISA assays concurrently except that there is usually no known protein concentration from which one can construct a standard response curve. Here, we describe a new method called 'serial dilution curve for RPPA data analysis'. Compared with the existing methods, the new method has the advantage of using fewer parameters and offering a simple way of visualizing the raw data. We showed how the method can be used to examine data quality and to obtain robust quantification of protein concentrations. AVAILABILITY A computer program in R for using serial dilution curve for RPPA data analysis is freely available at http://odin.mdacc.tmc.edu/~zhangli/RPPA.
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Affiliation(s)
- Li Zhang
- Department of Bioinformatics and Computational Biology, Department of Epidemiology, Department of Thoracic and Head and Neck Medical Oncology and Department of Systems Biology, The University of Texas MD Anderson Cancer Center, 1400 Pressler street, Unit 1410, Houston, TX 77030, USA,*To whom correspondence should be addressed
| | - Qingyi Wei
- Department of Bioinformatics and Computational Biology, Department of Epidemiology, Department of Thoracic and Head and Neck Medical Oncology and Department of Systems Biology, The University of Texas MD Anderson Cancer Center, 1400 Pressler street, Unit 1410, Houston, TX 77030, USA
| | - Li Mao
- Department of Bioinformatics and Computational Biology, Department of Epidemiology, Department of Thoracic and Head and Neck Medical Oncology and Department of Systems Biology, The University of Texas MD Anderson Cancer Center, 1400 Pressler street, Unit 1410, Houston, TX 77030, USA
| | - Wenbin Liu
- Department of Bioinformatics and Computational Biology, Department of Epidemiology, Department of Thoracic and Head and Neck Medical Oncology and Department of Systems Biology, The University of Texas MD Anderson Cancer Center, 1400 Pressler street, Unit 1410, Houston, TX 77030, USA
| | - Gordon B. Mills
- Department of Bioinformatics and Computational Biology, Department of Epidemiology, Department of Thoracic and Head and Neck Medical Oncology and Department of Systems Biology, The University of Texas MD Anderson Cancer Center, 1400 Pressler street, Unit 1410, Houston, TX 77030, USA
| | - Kevin Coombes
- Department of Bioinformatics and Computational Biology, Department of Epidemiology, Department of Thoracic and Head and Neck Medical Oncology and Department of Systems Biology, The University of Texas MD Anderson Cancer Center, 1400 Pressler street, Unit 1410, Houston, TX 77030, USA
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Morselli E, Galluzzi L, Kepp O, Vicencio JM, Criollo A, Maiuri MC, Kroemer G. Anti- and pro-tumor functions of autophagy. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1524-32. [PMID: 19371598 DOI: 10.1016/j.bbamcr.2009.01.006] [Citation(s) in RCA: 298] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2008] [Revised: 01/09/2009] [Accepted: 01/12/2009] [Indexed: 12/13/2022]
Abstract
Autophagy constitutes one of the major responses to stress in eukaryotic cells, and is regulated by a complex network of signaling cascades. Not surprisingly, autophagy is implicated in multiple pathological processes, including infection by pathogens, inflammatory bowel disease, neurodegeneration and cancer. Both oncogenesis and tumor survival are influenced by perturbations of the molecular machinery that controls autophagy. Numerous oncoproteins, including phosphatidylinositol 3-kinase, Akt1 and anti-apoptotic members of the Bcl-2 family suppress autophagy. Conversely, several tumor suppressor proteins (e.g., Atg4c; beclin 1; Bif-1; BH3-only proteins; death-associated protein kinase 1; LKB1/STK11; PTEN; UVRAG) promote the autophagic pathway. This does not entirely apply to p53, one of the most important tumor suppressor proteins, which regulates autophagy in an ambiguous fashion, depending on its subcellular localization. Irrespective of the controversial role of p53, basal levels of autophagy appear to inhibit tumor development. On the contrary, chemotherapy- and metabolic stress-induced activation of the autophagic pathway reportedly contribute to the survival of formed tumors, thereby favoring resistance. In this context, autophagy inhibition would represent a major therapeutic target for chemosensitization. Here, we will review the current knowledge on the dual role of autophagy as an anti- and pro-tumor mechanism.
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Longe HO, Romesser PB, Rankin AM, Faller DV, Eller MS, Gilchrest BA, Denis GV. Telomere homolog oligonucleotides induce apoptosis in malignant but not in normal lymphoid cells: mechanism and therapeutic potential. Int J Cancer 2009; 124:473-82. [PMID: 19003960 DOI: 10.1002/ijc.23946] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Human B- or T-cell lymphoma lines and primary murine lymphomas were treated with DNA oligonucleotides homologous to the telomere (TTAGGG repeat; "T-oligo"), either alone or in combination with standard, widely-used anticancer chemotherapeutic agents. T-oligo induces cell cycle arrest and apoptosis in cultured human or murine B or T-lymphoma cell lines and primary tumor cells, but exerts no detectable toxicity on normal human or murine primary lymphocytes. Exposure to T-oligo is hypothesized to mimic exposure of the 3' telomere repeat sequence, activating the ataxia telangiectasia mutated kinase, which phosphorylates downstream effectors such as p53, but effects are not dependent solely on functional p53. T-oligo causes early S-phase arrest and cooperates well with G(2)- or M-phase-specific anticancer agents; when combined at 1/10th of the conventional dose, vincristine and T-oligo produce greater-than-additive killing of human or murine lymphoma cells (78% of cells undergoing apoptosis after 6 hr vs. 5% of control cells). In mice, 1/10th of the conventional dose of a standard combination of cyclophosphamide, adriamycin, vincristine and prednisone is twice as effective when used in combination with low dose T-oligo. Thus, T-oligo sensitizes tumors to traditional anticancer agents and represents a potentially important new addition to the therapeutic arsenal for aggressive lymphomas.
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Affiliation(s)
- Harold O Longe
- Department of Medicine, Cancer Research Center, Boston University School of Medicine (BUSM), Boston, MA 02118, USA
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Jiang H, White EJ, Conrad C, Gomez-Manzano C, Fueyo J. Chapter 13 Autophagy Pathways in Glioblastoma. Methods Enzymol 2009; 453:273-86. [DOI: 10.1016/s0076-6879(08)04013-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Ramachandran N, Srivastava S, Labaer J. Applications of protein microarrays for biomarker discovery. Proteomics Clin Appl 2008; 2:1444-59. [PMID: 21136793 DOI: 10.1002/prca.200800032] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2008] [Indexed: 01/18/2023]
Abstract
The search for new biomarkers for diagnosis, prognosis, and therapeutic monitoring of diseases continues in earnest despite dwindling success at finding novel reliable markers. Some of the current markers in clinical use do not provide optimal sensitivity and specificity, with the prostate cancer antigen (PSA) being one of many such examples. The emergence of proteomic techniques and systems approaches to study disease pathophysiology has rekindled the quest for new biomarkers. In particular the use of protein microarrays has surged as a powerful tool for large-scale testing of biological samples. Approximately half the reports on protein microarrays have been published in the last two years especially in the area of biomarker discovery. In this review, we will discuss the application of protein microarray technologies that offer unique opportunities to find novel biomarkers.
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Affiliation(s)
- Niroshan Ramachandran
- Harvard Institute of Proteomics, Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Cambridge, MA, USA
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Telomerase inhibitors and 'T-oligo' as cancer therapeutics: contrasting molecular mechanisms of cytotoxicity. Anticancer Drugs 2008; 19:329-38. [PMID: 18454043 DOI: 10.1097/cad.0b013e3282f5d4c2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Telomeres, the specialized structures that comprise the ends of chromosomes, form a closed structure, or t-loop, that is important in preventing genomic instability. Forced modulation of this structure, via overexpression of a dominant-negative form of telomere repeat binding factor 2, a protein critical for maintaining t-loop structure, for example, can result in the activation of DNA-damage responses, and ultimately cellular senescence or apoptosis. This response is also seen in normal somatic cells, where telomeres steadily decrease in length as cellular proliferation occurs owing to inefficient replication of terminal telomeric DNA. When telomere length becomes critically short, t-loop structure is compromised, and the cell undergoes senescence. Telomerase, the enzyme responsible for telomere length maintenance, is overexpressed in a majority of cancers. Its lack of expression in most normal somatic cells makes it an attractive target in designing cancer therapeutics. Compounds currently under development that seek to inhibit hTERT, the reverse transcriptase component of telomerase, include nucleoside analogs and the small molecule BIBR1532. Compounds inhibiting the RNA component of telomerase, hTERC, include peptide nucleic acids, 2-5A antisense oligonucleotides, and N3'-P5' thio-phosphoramidates. Recently, an oligonucleotide sharing sequence homology with terminal telomeric DNA, termed 'T-oligo', has shown cytotoxic effects in multiple cancers in culture and animal models. Independent of telomerase function, T-oligo is thought to mimic the DNA-damage response a cell normally experiences when the telomere t-loop structure becomes dysfunctional. In this review, the molecular mechanisms attributed to telomerase inhibitors and T-oligo, as well as their potential as cancer therapeutics, are discussed.
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Ambroz KLH, Zhang Y, Schutz-Geschwender A, Olive DM. Blocking and detection chemistries affect antibody performance on reverse phase protein arrays. Proteomics 2008; 8:2379-83. [DOI: 10.1002/pmic.200700676] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Autophagy is an evolutionary conserved mechanism in eukaryotic cells that is known to process redundant or defective cellular proteins and organelles. The recent renewal of interest in autophagy research has led to a significant expansion in our understanding of the importance of autophagy in cellular health and disease. This invited review summarizes key elements of autophagy research, emphasizes those of particular interest to gastroenterologists, and offers insights into present and future research directions.
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Arad S, Zattra E, Hebert J, Epstein EH, Goukassian DA, Gilchrest BA. Topical thymidine dinucleotide treatment reduces development of ultraviolet-induced basal cell carcinoma in Ptch-1+/- mice. THE AMERICAN JOURNAL OF PATHOLOGY 2008; 172:1248-55. [PMID: 18403589 DOI: 10.2353/ajpath.2008.071117] [Citation(s) in RCA: 267] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Treatment with thymidine dinucleotide (pTT) has well documented DNA-protective effects and reduces development of squamous cell carcinoma in UV-irradiated mice. The preventive effect of pTT on basal cell carcinoma (BCC) was evaluated in UV-irradiated Ptch-1(+/-) mice, a model of the human disease Gorlin syndrome. Topical pTT treatment significantly reduced the number and size (P < 0.001) of BCCs in murine skin after 7 months of chronic irradiation. Skin biopsies collected 24 hours after the final UV exposure showed that pTT reduced the number of nuclei positive for cyclobutane pyrimidine dimers by 40% (P < 0.0002) and for 8-hydroxy-2'-deoxyguanosine by 61% (P < 0.01 compared with vehicle control). Immunostaining with an antibody specific for mutated p53 revealed 63% fewer positive patches in BCCs of pTT-treated mice compared with controls (P < 0.01), and the number of Ki-67-positive cells was decreased by 56% (P < 0.01) in pTT-treated tumor-free epidermis and by 76% (P < 0.001) in BCC tumor nests (P < 0.001). Terminal dUTP nick-end labeling staining revealed a 213% increase (P < 0.04) in the number of apoptotic cells in BCCs of pTT-treated mice. Cox-2 immunostaining was decreased by 80% in tumor-free epidermis of pTT-treated mice compared with controls (P < 0.01). We conclude that topical pTT treatment during a prolonged period of intermittent UV exposure decreases the number and size of UV-induced BCCs through several anti-cancer mechanisms.
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Affiliation(s)
- Simin Arad
- Department of Dermatology, Boston University School of Medicine, 609 Albany St., Boston, MA 02118, USA
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Yaar M, Eller MS, Panova I, Kubera J, Wee LH, Cowan KH, Gilchrest BA. Telomeric DNA induces apoptosis and senescence of human breast carcinoma cells. Breast Cancer Res 2007; 9:R13. [PMID: 17257427 PMCID: PMC1851376 DOI: 10.1186/bcr1646] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Revised: 11/22/2006] [Accepted: 01/26/2007] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION Cancer is a leading cause of death in Americans. We have identified an inducible cancer avoidance mechanism in cells that reduces mutation rate, reduces and delays carcinogenesis after carcinogen exposure, and induces apoptosis and/or senescence of already transformed cells by simultaneously activating multiple overlapping and redundant DNA damage response pathways. METHODS The human breast carcinoma cell line MCF-7, the adriamycin-resistant MCF-7 (Adr/MCF-7) cell line, as well as normal human mammary epithelial (NME) cells were treated with DNA oligonucleotides homologous to the telomere 3' overhang (T-oligos). SCID mice received intravenous injections of MCF-7 cells followed by intravenous administration of T-oligos. RESULTS Acting through ataxia telangiectasia mutated (ATM) and its downstream effectors, T-oligos induced apoptosis and senescence of MCF-7 cells but not NME cells, in which these signaling pathways were induced to a far lesser extent. In MCF-7 cells, experimental telomere loop disruption caused identical responses, consistent with the hypothesis that T-oligos act by mimicking telomere overhang exposure. In vivo, T-oligos greatly prolonged survival of SCID mice following intravenous injection of human breast carcinoma cells. CONCLUSION By inducing DNA damage-like responses in MCF-7 cells, T-oligos provide insight into innate cancer avoidance mechanisms and may offer a novel approach to treatment of breast cancer and other malignancies.
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Affiliation(s)
- Mina Yaar
- Department of Dermatology, Boston University School of Medicine, Albany Street Boston, MA 02118-2394, USA
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Albany Street, Boston, MA 02118-2394, USA
| | - Mark S Eller
- Department of Dermatology, Boston University School of Medicine, Albany Street Boston, MA 02118-2394, USA
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Albany Street, Boston, MA 02118-2394, USA
| | - Izabela Panova
- Department of Dermatology, Boston University School of Medicine, Albany Street Boston, MA 02118-2394, USA
| | - John Kubera
- Department of Dermatology, Boston University School of Medicine, Albany Street Boston, MA 02118-2394, USA
| | - Lee Hng Wee
- Department of Dermatology, Boston University School of Medicine, Albany Street Boston, MA 02118-2394, USA
| | - Kenneth H Cowan
- Cancer Center, Boston University School of Medicine, Albany Street, Boston, MA 02118-2394, USA
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, 68198-6805, USA
| | - Barbara A Gilchrest
- Department of Dermatology, Boston University School of Medicine, Albany Street Boston, MA 02118-2394, USA
- Cancer Center, Boston University School of Medicine, Albany Street, Boston, MA 02118-2394, USA
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