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Ascanelli C, Dahir R, Wilson CH. Manipulating Myc for reparative regeneration. Front Cell Dev Biol 2024; 12:1357589. [PMID: 38577503 PMCID: PMC10991803 DOI: 10.3389/fcell.2024.1357589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/15/2024] [Indexed: 04/06/2024] Open
Abstract
The Myc family of proto-oncogenes is a key node for the signal transduction of external pro-proliferative signals to the cellular processes required for development, tissue homoeostasis maintenance, and regeneration across evolution. The tight regulation of Myc synthesis and activity is essential for restricting its oncogenic potential. In this review, we highlight the central role that Myc plays in regeneration across the animal kingdom (from Cnidaria to echinoderms to Chordata) and how Myc could be employed to unlock the regenerative potential of non-regenerative tissues in humans for therapeutic purposes. Mastering the fine balance of harnessing the ability of Myc to promote transcription without triggering oncogenesis may open the door to many exciting opportunities for therapeutic development across a wide array of diseases.
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Affiliation(s)
| | | | - Catherine H. Wilson
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
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2
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Jana S, Brahma S, Arora S, Wladyka CL, Hoang P, Blinka S, Hough R, Horn JL, Liu Y, Wang LJ, Depeille P, Smith E, Montgomery RB, Lee JK, Haffner MC, Vakar-Lopez F, Grivas P, Wright JL, Lam HM, Black PC, Roose JP, Ryazanov AG, Subramaniam AR, Henikoff S, Hsieh AC. Transcriptional-translational conflict is a barrier to cellular transformation and cancer progression. Cancer Cell 2023; 41:853-870.e13. [PMID: 37084735 PMCID: PMC10208629 DOI: 10.1016/j.ccell.2023.03.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 01/31/2023] [Accepted: 03/24/2023] [Indexed: 04/23/2023]
Abstract
We uncover a tumor-suppressive process in urothelium called transcriptional-translational conflict caused by deregulation of the central chromatin remodeling component ARID1A. Loss of Arid1a triggers an increase in a nexus of pro-proliferation transcripts, but a simultaneous inhibition of the eukaryotic elongation factor 2 (eEF2), which results in tumor suppression. Resolution of this conflict through enhancing translation elongation speed enables the efficient and precise synthesis of a network of poised mRNAs resulting in uncontrolled proliferation, clonogenic growth, and bladder cancer progression. We observe a similar phenomenon in patients with ARID1A-low tumors, which also exhibit increased translation elongation activity through eEF2. These findings have important clinical implications because ARID1A-deficient, but not ARID1A-proficient, tumors are sensitive to pharmacologic inhibition of protein synthesis. These discoveries reveal an oncogenic stress created by transcriptional-translational conflict and provide a unified gene expression model that unveils the importance of the crosstalk between transcription and translation in promoting cancer.
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Affiliation(s)
- Sujata Jana
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Sandipan Brahma
- Basic Science Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Sonali Arora
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Cynthia L Wladyka
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Patrick Hoang
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Steven Blinka
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Rowan Hough
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Jessie L Horn
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Yuzhen Liu
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Li-Jie Wang
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Philippe Depeille
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Eric Smith
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | | | - John K Lee
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Michael C Haffner
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Funda Vakar-Lopez
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Petros Grivas
- Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Jonathan L Wright
- Department of Urology, University of Washington, Seattle, WA 98915, USA
| | - Hung-Ming Lam
- Department of Urology, University of Washington, Seattle, WA 98915, USA
| | - Peter C Black
- Vancouver Prostate Centre, Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Jeroen P Roose
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Alexey G Ryazanov
- Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | | | - Steven Henikoff
- Basic Science Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Howard Hughes Medical Institute, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Andrew C Hsieh
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA; Genome Sciences, University of Washington, Seattle, WA 98915, USA.
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3
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Sei Y, Feng J, Zhao X, Dagur P, McCoy JP, Merchant JL, Wank SA. Tissue- and cell-specific properties of enterochromaffin cells affect the fate of tumorigenesis toward nonendocrine adenocarcinoma of the small intestine. Am J Physiol Gastrointest Liver Physiol 2023; 324:G177-G189. [PMID: 36537709 PMCID: PMC9925174 DOI: 10.1152/ajpgi.00205.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 11/16/2022] [Accepted: 12/14/2022] [Indexed: 01/31/2023]
Abstract
Small intestinal neuroendocrine tumors (SI-NETs) are serotonin-secreting well-differentiated neuroendocrine tumors of putative enterochromaffin (EC) cell origin. However, EC cell-derived tumorigenesis remains poorly understood. Here, we examined whether the gain of Myc and the loss of RB1 and Trp53 function in EC cells result in SI-NET using tryptophan hydroxylase 1 (TPH1) Cre-ERT2-driven RB1fl Trp53fl MycLSL (RPM) mice. TPH1-Cre-induced gain of Myc and loss of RB1 and Trp53 function resulted in endocrine or neuronal tumors in pancreas, lung, enteric neurons, and brain. Lineage tracing indicated that the cellular origin for these tumors was TPH1-expressing neuroendocrine, neuronal, or their precursor cells in these organs. However, despite that TPH1 is most highly expressed in EC cells of the small intestine, we observed no incidence of EC cell tumors. Instead, the tumor of epithelial cell origin in the intestine was exclusively nonendocrine adenocarcinoma, suggesting dedifferentiation of EC cells into intestinal stem cells (ISCs) as a cellular mechanism. Furthermore, ex vivo organoid studies indicated that loss of functions of Rb1 and Trp53 accelerated dedifferentiation of EC cells that were susceptible to apoptosis with expression of activated MycT58A, suggesting that the rare dedifferentiating cells escaping cell death went on to develop adenocarcinomas. Lineage tracing demonstrated that EC cells in the small intestine were short-lived compared with neuroendocrine or neuronal cells in other organs. In contrast, EC cell-derived ISCs were long-lasting and actively cycling and thus susceptible to transformation. These results suggest that tissue- and cell-specific properties of EC cells such as rapid cell turnover and homeostatic dedifferentiation, affect the fate and rate of tumorigenesis induced by genetic alterations and provide important insights into EC cell-derived tumorigenesis.NEW & NOTEWORTHY Small intestinal neuroendocrine tumors are of putative enterochromaffin (EC) cell origin and are the most common malignancy in the small intestine, followed by adenocarcinoma. However, the tumorigenesis of these tumor types remains poorly understood. The present lineage tracing studies showed that tissue- and cell-specific properties of EC cells such as rapid cell turnover and homeostatic dedifferentiation affect the fate and rate of tumorigenesis induced by genetic alterations toward a rare occurrence of adenocarcinoma.
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Affiliation(s)
- Yoshitatsu Sei
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Jianying Feng
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Xilin Zhao
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Pradeep Dagur
- Flow Cytometry Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - J Philip McCoy
- Flow Cytometry Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Juanita L Merchant
- Department of Internal Medicine-Gastroenterology, University of Arizona, Tuscan, Arizona
| | - Stephen A Wank
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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Pei H, Guo W, Peng Y, Xiong H, Chen Y. Targeting key proteins involved in transcriptional regulation for cancer therapy: Current strategies and future prospective. Med Res Rev 2022; 42:1607-1660. [PMID: 35312190 DOI: 10.1002/med.21886] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/10/2022] [Accepted: 02/22/2022] [Indexed: 12/14/2022]
Abstract
The key proteins involved in transcriptional regulation play convergent roles in cellular homeostasis, and their dysfunction mediates aberrant gene expressions that underline the hallmarks of tumorigenesis. As tumor progression is dependent on such abnormal regulation of transcription, it is important to discover novel chemical entities as antitumor drugs that target key tumor-associated proteins involved in transcriptional regulation. Despite most key proteins (especially transcription factors) involved in transcriptional regulation are historically recognized as undruggable targets, multiple targeting approaches at diverse levels of transcriptional regulation, such as epigenetic intervention, inhibition of DNA-binding of transcriptional factors, and inhibition of the protein-protein interactions (PPIs), have been established in preclinically or clinically studies. In addition, several new approaches have recently been described, such as targeting proteasomal degradation and eliciting synthetic lethality. This review will emphasize on accentuating these developing therapeutic approaches and provide a thorough conspectus of the drug development to target key proteins involved in transcriptional regulation and their impact on future oncotherapy.
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Affiliation(s)
- Haixiang Pei
- Institute for Advanced Study, Shenzhen University and Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen, China.,Shanghai Key Laboratory of Regulatory Biology, The Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai, China
| | - Weikai Guo
- Shanghai Key Laboratory of Regulatory Biology, The Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai, China.,Joint National Laboratory for Antibody Drug Engineering, School of Basic Medical Science, Henan University, Kaifeng, China
| | - Yangrui Peng
- Shanghai Key Laboratory of Regulatory Biology, The Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai, China
| | - Hai Xiong
- Institute for Advanced Study, Shenzhen University and Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen, China
| | - Yihua Chen
- Shanghai Key Laboratory of Regulatory Biology, The Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai, China
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Fairlie WD, Lee EF. Co-Operativity between MYC and BCL-2 Pro-Survival Proteins in Cancer. Int J Mol Sci 2021; 22:2841. [PMID: 33799592 PMCID: PMC8000576 DOI: 10.3390/ijms22062841] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 12/30/2022] Open
Abstract
B-Cell Lymphoma 2 (BCL-2), c-MYC and related proteins are arguably amongst the most widely studied in all of biology. Every year there are thousands of papers reporting on different aspects of their biochemistry, cellular and physiological mechanisms and functions. This plethora of literature can be attributed to both proteins playing essential roles in the normal functioning of a cell, and by extension a whole organism, but also due to their central role in disease, most notably, cancer. Many cancers arise due to genetic lesions resulting in deregulation of both proteins, and indeed the development and survival of tumours is often dependent on co-operativity between these protein families. In this review we will discuss the individual roles of both proteins in cancer, describe cancers where co-operativity between them has been well-characterised and finally, some strategies to target these proteins therapeutically.
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Affiliation(s)
- Walter Douglas Fairlie
- Olivia Newton-John Cancer Research Institute, Heidelberg, VIC 3084, Australia;
- School of Cancer Medicine, La Trobe University, Melbourne, VIC 3084, Australia
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC 3084, Australia
| | - Erinna F. Lee
- Olivia Newton-John Cancer Research Institute, Heidelberg, VIC 3084, Australia;
- School of Cancer Medicine, La Trobe University, Melbourne, VIC 3084, Australia
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC 3084, Australia
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6
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Mammas IN. Clinical Virology research and medical education in Greece: An interview with Demetrios A. Spandidos, Professor of Clinical Virology at the University of Crete in Greece. Exp Ther Med 2019; 18:3221-3225. [PMID: 31588212 PMCID: PMC6766560 DOI: 10.3892/etm.2019.7946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 08/26/2019] [Indexed: 12/15/2022] Open
Abstract
Professor Demetrios A. Spandidos, Professor Emeritus of Clinical Virology at the University of Crete School of Medicine in Crete, Greece, is a pioneer in world research in Virology, Oncology and medical education. He has been the first Professor of Clinical Virology at the University of Crete School of Medicine, the only School of Medicine with a separate Department of Clinical Virology in Greece. According to Professor Spandidos, the understanding of the interactions of viruses with human host cells is what enables the development of new vaccines and new therapies against a wide range of diseases in humans, including cancer. Over the past two decades, the expansion of new knowledge, treatments, prevention and management options and the emerging needs on neonatal and paediatric viral infections have made the role of future paediatric virologists more than necessary. For this reason, he strongly believes that Paediatric Virology should be recognized as a new paediatric subspecialty. Professor Spandidos declares that medical education is a continuous sequence from undergraduate to postgraduate/specialty/subspecialty medical training and continuing learning. He also supports the concept that the future of medical education represents the future of Medicine.
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Affiliation(s)
- Ioannis N Mammas
- Laboratory of Clinical Virology, School of Medicine, University of Crete, 71003 Heraklion, Greece.,First Department of Paediatrics, University of Athens School of Medicine, 11527 Athens, Greece.,Paediatric Clinic, Aliveri, 34500 Island of Euboea, Greece
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7
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Soto DR, Barton C, Munger K, McLaughlin-Drubin ME. KDM6A addiction of cervical carcinoma cell lines is triggered by E7 and mediated by p21CIP1 suppression of replication stress. PLoS Pathog 2017; 13:e1006661. [PMID: 28968467 PMCID: PMC5638616 DOI: 10.1371/journal.ppat.1006661] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 10/12/2017] [Accepted: 09/21/2017] [Indexed: 12/13/2022] Open
Abstract
Expression of E7 proteins encoded by carcinogenic, high-risk human papillomaviruses (HPVs) triggers increased expression of the histone H3 lysine 27 demethylase KDM6A. KDM6A expression is necessary for survival of high-risk HPV E7 expressing cells, including several cervical cancer lines. Here we show that increased KDM6A in response to high-risk HPV E7 expression causes epigenetic de-repression of the cell cycle and DNA replication inhibitor p21CIP1, and p21CIP1 expression is necessary for survival of high-risk HPV E7 expressing cells. The requirement for KDM6A and p21CIP1 expression for survival of high-risk HPV E7 expressing cells is based on p21CIP1’s ability to inhibit DNA replication through PCNA binding. We show that ectopic expression of cellular replication factors can rescue the loss of cell viability in response to p21CIP1 and KDM6A depletion. Moreover, we discovered that nucleoside supplementation will override the loss of cell viability in response to p21CIP1 depletion, suggesting that p21CIP1 depletion causes lethal replication stress. This model is further supported by increased double strand DNA breaks upon KDM6A or p21CIP1 depletion and DNA combing experiments that show aberrant re-replication upon KDM6A or p21CIP1 depletion in high-risk HPV E7 expressing cells. Therefore, KDM6A and p21CIP1 expression are essential to curb E7 induced replication stress to levels that do not markedly interfere with cell viability. High-risk human papillomaviruses (HPVs) are associated with approximately five percent of all human cancers, including virtually all cervical cancers as well as a large percentage of anal, vaginal, vulvar, penile, and oropharyngeal cancers. The HPV E6 and E7 proteins are the major oncogenic drivers in these tumors, and persistent expression of E6 and E7 is required for the maintenance of the transformed state. While E6 and E7 lack intrinsic enzymatic activities, and thus are difficult to directly target therapeutically, they biochemically interact with, functionally modify, or alter expression of key host cellular signaling proteins. HPV16 E7 triggers increased expression of the KDM6A histone demethylase, and KDM6A expression becomes necessary for the survival of HPV16 E7 expressing cells. Here we show that the requirement for persistent KDM6A expression is mediated by the cell cycle and DNA replication inhibitor p21CIP1 in that p21CIP1 expression is necessary for survival of E7 expressing cells. Remarkably, this is based on the ability of p21CIP1 to inhibit cellular DNA replication by binding PCNA. Our results suggest that increased KDM6A and p21CIP1 expression serves to curb HPV16 E7-induced replication stress to levels that are conducive to DNA replication but do not cause death of HPV infected cells.
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Affiliation(s)
- David R. Soto
- Infectious Diseases Division, Department of Medicine, The Channing Laboratory, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Christopher Barton
- Infectious Diseases Division, Department of Medicine, The Channing Laboratory, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Karl Munger
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Margaret E. McLaughlin-Drubin
- Infectious Diseases Division, Department of Medicine, The Channing Laboratory, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Zou Z, Chen J, Liu A, Zhou X, Song Q, Jia C, Chen Z, Lin J, Yang C, Li M, Jiang Y, Bai X. mTORC2 promotes cell survival through c-Myc-dependent up-regulation of E2F1. J Cell Biol 2016; 211:105-22. [PMID: 26459601 PMCID: PMC4602034 DOI: 10.1083/jcb.201411128] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Inactivation of mTORC2 reduces PP2A activity toward c-Myc serine 62 (S62), leading to enhancement of c-Myc phosphorylation and expression and increased transcription of pri-miR-9-2/miR-9-3p, which in turn suppresses E2F1 and enhances apoptosis. Previous studies have reported that mTORC2 promotes cell survival through phosphorylating AKT and enhancing its activity. We reveal another mechanism by which mTORC2 controls apoptosis. Inactivation of mTORC2 promotes binding of CIP2A to PP2A, leading to reduced PP2A activity toward c-Myc serine 62 and, consequently, enhancement of c-Myc phosphorylation and expression. Increased c-Myc activity induces transcription of pri-miR-9-2/miR-9-3p, in turn inhibiting expression of E2F1, a transcriptional factor critical for cancer cell survival and tumor progression, resulting in enhanced apoptosis. In vivo experiments using B cell–specific mTORC2 (rapamycin-insensitive companion of mTOR) deletion mice and a xenograft tumor model confirmed that inactivation of mTORC2 causes up-regulation of c-Myc and miR-9-3p, down-regulation of E2F1, and consequent reduction in cell survival. Conversely, Antagomir-9-3p reversed mTORC1/2 inhibitor–potentiated E2F1 suppression and resultant apoptosis in xenograft tumors. Our in vitro and in vivo findings collectively demonstrate that mTORC2 promotes cell survival by stimulating E2F1 expression through a c-Myc– and miR-9-3p–dependent mechanism.
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Affiliation(s)
- Zhipeng Zou
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Juan Chen
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Anling Liu
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Xuan Zhou
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Qiancheng Song
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Chunhong Jia
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Zhenguo Chen
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Jun Lin
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Cuilan Yang
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Ming Li
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Yu Jiang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
| | - Xiaochun Bai
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China
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Abstract
MYC expression is tightly correlated with cell-cycle progression in normal tissues, whereas unchecked MYC expression is among the most prominent hallmarks of the hyperproliferation associated with most forms of cancer. At first glance it might seem counterintuitive that MYC is also among the most robust agents of programmed cell death (apoptosis) in mammalian cells. However it is clearly beneficial for a multicellular organism to have a mechanism for triggering death in cells that express potentially oncogenic levels of MYC. Decades of intense study have begun to provide an understanding of the mechanisms that regulate MYC's seemingly split personality. Key features of MYC-induced apoptosis will be discussed here along with examples of how our understanding of this pathway might be exploited for the therapeutic benefit of cancer patients.
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Affiliation(s)
- Steven B McMahon
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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10
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Glehr M, Fritsch-Breisach M, Lohberger B, Walzer SM, Moazedi-Fuerst F, Rinner B, Gruber G, Graninger W, Leithner A, Windhager R. Influence of resveratrol on rheumatoid fibroblast-like synoviocytes analysed with gene chip transcription. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2013; 20:310-318. [PMID: 23137833 DOI: 10.1016/j.phymed.2012.09.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 08/16/2012] [Accepted: 09/21/2012] [Indexed: 06/01/2023]
Abstract
Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease that primarily attacks joints and is therefore a common cause of chronic disability and articular destruction. The hyperplastic growth of RA-fibroblast-like synoviocytes (FLSs) and their resistance against apoptosis are considered pathological hallmarks of RA. The natural antioxidant resveratrol is known for its antiproliferative and pro-apoptotic properties. This study investigated the effect of resveratrol on RA-FLS. RA-FLS were isolated from the synovium of 10 RA patients undergoing synovectomy or joint replacement surgery. RA-FLS were first stressed by pre-incubation with interleukin 1beta (IL-1β) and then treated with 100 μM resveratrol for 24h. In order to evaluate the influence of resveratrol on the transcription of genes, a Gene Chip Human Gene 1.0 ST Array was applied. In addition, the effect of dexamethasone on proliferation and apoptosis of RA-FLS was compared with that of resveratrol. Gene array analysis showed highly significant effects of resveratrol on the expression of genes involved in mitosis, cell cycle, chromosome segregation and apoptosis. qRT-PCR, caspase-3/7 and proliferation assays confirmed the results of gene array analysis. In comparison, dexamethasone showed little to no effect on reducing cell proliferation and apoptosis. Our in vitro findings point towards resveratrol as a promising new therapeutic approach for local intra-articular application against RA, and further clinical studies will be necessary.
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Affiliation(s)
- Mathias Glehr
- Department of Orthopaedic Surgery, Medical University of Graz, Graz, Austria
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11
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McEwan MV, Eccles MR, Horsfield JA. Cohesin is required for activation of MYC by estradiol. PLoS One 2012; 7:e49160. [PMID: 23145106 PMCID: PMC3493498 DOI: 10.1371/journal.pone.0049160] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 10/09/2012] [Indexed: 12/13/2022] Open
Abstract
Cohesin is best known as a multi-subunit protein complex that holds together replicated sister chromatids from S phase until G2. Cohesin also has an important role in the regulation of gene expression. We previously demonstrated that the cohesin complex positively regulates expression of the oncogene MYC. Cell proliferation driven by MYC contributes to many cancers, including breast cancer. The MYC oncogene is estrogen-responsive and a transcriptional target of estrogen receptor alpha (ERα). Estrogen-induced cohesin binding sites coincide with ERα binding at the MYC locus, raising the possibility that cohesin and ERα combine actions to regulate MYC transcription. The objective of this study was to investigate a putative role for cohesin in estrogen induction of MYC expression. We found that siRNA-targeted depletion of a cohesin subunit, RAD21, decreased MYC expression in ER-positive (MCF7 and T47D) and ER-negative (MDA-MB-231) breast cancer cell lines. In addition, RAD21 depletion blocked estradiol-mediated activation of MYC in ER-positive cell lines, and decreased ERα binding to estrogen response elements (EREs) upstream of MYC, without affecting total ERα levels. Treatment of MCF7 cells with estradiol caused enrichment of RAD21 binding at upstream enhancers and at the P2 promoter of MYC. Enriched binding at all sites, except the P2 promoter, was dependent on ERα. Since RAD21 depletion did not affect transcription driven by an exogenous reporter construct containing a naked ERE, chromatin-based mechanisms are likely to be involved in cohesin-dependent MYC transcription. This study demonstrates that ERα activation of MYC can be modulated by cohesin. Together, these results demonstrate a novel role for cohesin in estrogen-mediated regulation of MYC and the first evidence that cohesin plays a role in ERα binding.
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Affiliation(s)
- Miranda V. McEwan
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Michael R. Eccles
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Julia A. Horsfield
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
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Manosroi J, Sainakham M, Manosroi W, Manosroi A. Anti-proliferative and apoptosis induction activities of extracts from Thai medicinal plant recipes selected from MANOSROI II database. JOURNAL OF ETHNOPHARMACOLOGY 2012; 141:451-459. [PMID: 22440260 DOI: 10.1016/j.jep.2012.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 02/20/2012] [Accepted: 03/05/2012] [Indexed: 05/31/2023]
Abstract
UNLABELLED ETHONOPHARMACOLOGICAL RELEVANCES: Traditional medicines have long been used by the Thai people. Several medicinal recipes prepared from a mixture of plants are often used by traditional medicinal practitioners for the treatment of many diseases including cancer. The recipes collected from the Thai medicinal text books were recorded in MANOSROI II database. Anticancer recipes were searched and selected by a computer program using the recipe indication keywords including Ma-reng and San which means cancer in Thai, from the database for anticancer activity investigation. AIM OF STUDY To investigate anti-cancer activities of the Thai medicinal plant recipes selected from the "MANOSROI II" database. MATERIALS AND METHODS Anti-proliferative and apoptotic activities of extracts from 121 recipes selected from 56,137 recipes in the Thai medicinal plant recipe "MANOSROI II" database were investigated in two cancer cell lines including human mouth epidermal carcinoma (KB) and human colon adenocarcinoma (HT-29) cell lines using sulforhodamine B (SRB) assay and acridine orange (AO) and ethidium bromide (EB) staining technique, respectively. RESULTS AND CONCLUSIONS In the SRB assay, recipes NE028 and, S003 gave the highest anti-proliferation activity on KB and HT29 with the IC(50) values of 2.48±0.24 and 6.92±0.49μg/ml, respectively. In the AO/EB staining assay, recipes S016 and NE028 exhibited the highest apoptotic induction in KB and HT-29 cell lines, respectively. This study has demonstrated that the three Thai medicinal plant recipes selected from "MANOSROI II" database (NE028, S003 and S016) gave active anti-cancer activities according to the NCI classification which can be further developed for anti-cancer treatment.
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Affiliation(s)
- Jiradej Manosroi
- Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand.
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13
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Scott N, Martin I, Jack AS, Dixon MF, Quirke P. Genes mediating programmed cell death: an immunohistochemical study of bcl-2, c-myc and p53 expression in colorectal neoplasia. Mol Pathol 2010; 49:M151-8. [PMID: 16696064 PMCID: PMC408042 DOI: 10.1136/mp.49.3.m151] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Aims-To describe the expression of three genes involved in the regulation of cell proliferation and programmed cell death (apoptosis) in normal, dysplastic and malignant large bowel epithelium, and to relate any alterations to important biological and clinical variables.Methods-Immunohistochemistry was used to assess bcl-2, c-myc and p53 gene expression in 70 colorectal carcinomas, 36 adenomas and three samples of normal mucosa.Results-Bcl-2 and c-myc protein were detected in all samples of normal mucosa and most adenomas. P53 was never found in normal mucosa and was expressed in only 5% of adenomas. Sixty nine of 70 carcinomas expressed c-myc protein; p53 was found in 46% and bcl-2 was present in 35%. Bcl-2 expression correlated with a higher degree of tumour differentiation whereas the opposite was true for c-myc. Strong staining for c-myc protein predicted survival in univariate analysis. No correlation was found between p53 and bcl-2 expression.Conclusions-While c-myc and bcl-2 proteins are overexpressed at an early stage of the large bowel adenoma-carcinoma sequence, alterations to the p53 protein level only occur as a late event in large, highly dysplastic adenomas and carcinomas. Bcl-2 may therefore protect the growing adenoma against excessive programmed cell death and mutated p53 may play a similar role in carcinomas. In vitro there is a reciprocal relation between p53 and bcl-2 expression. This could not be confirmed in vivo. Similarly, there was no relation between bcl-2 and c-myc status, despite evidence that these proteins cooperate to cause neoplastic transformation. C-myc may be a prognostic indicator in large bowel cancer. There is no evidence in the present series that bcl-2 status will affect survival.
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Affiliation(s)
- N Scott
- Department of Histopathology, Centre for Digestive Diseases
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14
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Haeno H, Michor F. The evolution of tumor metastases during clonal expansion. J Theor Biol 2009; 263:30-44. [PMID: 19917298 DOI: 10.1016/j.jtbi.2009.11.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2009] [Revised: 10/02/2009] [Accepted: 11/05/2009] [Indexed: 01/28/2023]
Abstract
Cancer is a leading cause of morbidity and mortality in many countries. Solid tumors generally initiate at one particular site called the primary tumor, but eventually disseminate and form new colonies in other organs. The development of such metastases greatly diminishes the potential for a cure of patients and is thought to represent the final stage of the multi-stage progression of human cancer. The concept of early metastatic dissemination, however, postulates that cancer cell spread might arise early during the development of a tumor. It is important to know whether metastases are present at diagnosis since this determines treatment strategies and outcome. In this paper, we design a stochastic mathematical model of the evolution of tumor metastases in an expanding cancer cell population. We calculate the probability of metastasis at a given time during tumor evolution, the expected number of metastatic sites, and the total number of cancer cells as well as metastasized cells. Furthermore, we investigate the effect of drug administration and tumor resection on these quantities and predict the survival time of cancer patients. The model presented in this paper allows us to determine the probability and number of metastases at diagnosis and to identify the optimum treatment strategy to maximally prolong survival of cancer patients.
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Affiliation(s)
- Hiroshi Haeno
- Computational Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
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15
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Allan DJ. Radiation-induced Apoptosis: Its Role in a MADCaT (Mitosis-opoptosis-differentiation-calcium Toxicity) Scheme of Cytotoxicity Mechanisms. Int J Radiat Biol 2009; 62:145-52. [PMID: 1355507 DOI: 10.1080/09553009214551951] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- D J Allan
- Centre for Molecular Biotechnology, Queensland University of Technology, Brisbane, Australia
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16
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Lymbouridou R, Soufla G, Chatzinikola AM, Vakis A, Spandidos DA. Down-regulation of K-ras and H-ras in human brain gliomas. Eur J Cancer 2009; 45:1294-1303. [PMID: 19179066 DOI: 10.1016/j.ejca.2008.12.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 12/17/2008] [Accepted: 12/19/2008] [Indexed: 10/21/2022]
Abstract
Ras genes, a class of nucleotide-binding proteins that regulate normal and transformed cell growth, have been scarcely investigated in human brain tumours. We evaluated the mutational, mRNA and protein expression profile of the ras genes in 21 glioblastomas multiforme (grade IV), four fibrillary astrocytoma (grade II), four anaplastic astrocytoma (grade III) and 15 normal specimens. K-, H- and N-ras transcript levels were determined by real-time RT-PCR and mutational status by PCR-restriction fragment length polymorphism (RFLP) and direct sequencing. p21 protein was evaluated by Western blot analysis. Two K-ras mutations were found in codons 16 and 26 in one pathological and one normal sample, respectively. Glioblastoma multiforme cases exhibited significantly lower K- and H-ras mRNA levels compared to controls (P < 10(-4)). K- and H-ras mRNA down-regulation was not associated with patient outcome or survival. K-ras was positively correlated with H-ras in glioblastomas (P = 0.005), but not in normal specimens. p21 protein was absent in all samples. Our findings provide evidence of K- and H-ras involvement in brain malignant transformation through transcriptional down-regulation, while N-ras seems to contribute less to brain carcinogenesis.
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Affiliation(s)
- Rena Lymbouridou
- Department of Virology, Faculty of Medicine, Medical School, University of Crete, P.O. Box 1527, Heraklion 710 03, Crete, Greece
| | - Giannoula Soufla
- Department of Virology, Faculty of Medicine, Medical School, University of Crete, P.O. Box 1527, Heraklion 710 03, Crete, Greece
| | - Anthoula M Chatzinikola
- Department of Virology, Faculty of Medicine, Medical School, University of Crete, P.O. Box 1527, Heraklion 710 03, Crete, Greece
| | - Antonios Vakis
- Department of Neurosurgery, University Hospital of Heraklion, Crete, Greece
| | - Demetrios A Spandidos
- Department of Virology, Faculty of Medicine, Medical School, University of Crete, P.O. Box 1527, Heraklion 710 03, Crete, Greece.
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17
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Slee EA, Martin SJ. Regulation of caspase activation in apoptosis: implications for transformation and drug resistance. Cytotechnology 2008; 27:309-20. [PMID: 19002801 DOI: 10.1023/a:1008014215581] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recent developments in the apoptosis field have uncovered a family of cysteine proteases, the Caspases, that act as signalling components as well as effectors of the cell death machinery. Caspases are constitutively present as inactive precursors within most cells and undergo proteolytic processing in response to diverse death-inducing stimuli to initiate the death programme. Active caspases can process other caspases of the same type as well as process caspases further downstream in the pathway that ultimately leads to collapse of the cell. This cellular collapse is thought to occur as a consequence of caspase-mediated cleavage of a diverse array of cellular substrates. Regulation of entry into the death programme is controlled at a number of levels by members of the Bcl-2 family, as well as by other cell death regulatory proteins. Recent data has shed light upon the mechanism of action of these regulatory molecules and suggests that the point of caspase activation is a major checkpoint in the cell death programme. Because many transformed cell populations possess derangements in cell death-regulatory genes, such as bcl-2, such cells frequently exhibit elevated resistance to cytotoxic chemotherapy. Thus, a deeper understanding of how apoptosis is normally regulated has therapeutic implications for disease states where the normal controls on the cell death machinery have been subverted.
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Affiliation(s)
- E A Slee
- Department of Biology, National University of Ireland, Maynooth, Co, Kildare, Ireland
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18
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19
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Haeno H, Iwasa Y, Michor F. The evolution of two mutations during clonal expansion. Genetics 2007; 177:2209-21. [PMID: 18073428 PMCID: PMC2219486 DOI: 10.1534/genetics.107.078915] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Accepted: 10/08/2007] [Indexed: 12/15/2022] Open
Abstract
Knudson's two-hit hypothesis proposes that two genetic changes in the RB1 gene are the rate-limiting steps of retinoblastoma. In the inherited form of this childhood eye cancer, only one mutation emerges during somatic cell divisions while in sporadic cases, both alleles of RB1 are inactivated in the growing retina. Sporadic retinoblastoma serves as an example of a situation in which two mutations are accumulated during clonal expansion of a cell population. Other examples include evolution of resistance against anticancer combination therapy and inactivation of both alleles of a metastasis-suppressor gene during tumor growth. In this article, we consider an exponentially growing population of cells that must evolve two mutations to (i) evade treatment, (ii) make a step toward (invasive) cancer, or (iii) display a disease phenotype. We calculate the probability that the population has evolved both mutations before it reaches a certain size. This probability depends on the rates at which the two mutations arise; the growth and death rates of cells carrying none, one, or both mutations; and the size the cell population reaches. Further, we develop a formula for the expected number of cells carrying both mutations when the final population size is reached. Our theory establishes an understanding of the dynamics of two mutations during clonal expansion.
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Affiliation(s)
- Hiroshi Haeno
- Department of Biology, Kyushu University, Fukuoka, Japan
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20
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Abstract
The protein product of nm23-H1 gene has activity of nucleoside diphosphate (NDP) kinase, which catalyzes the phosphorylation of nucleoside diphosphates to the corresponding nucleoside triphosphates. Reductions in nm23 expression have been significantly associated with aggressive behavior in melanoma, breast, colon, and gastric carcinomas. On the contrary, high levels of nm23 gene expression are noted in the advanced stage of thyroid carcinomas and associated with significant reductions in survival for neuroblastoma and osteosarcoma patients. Although expression of nm23/NDP kinase is divergent in various malignant tumors, its reduced expression seems to be related to increased metastatic potential in most carcinoma types. However, it is hypothesized that nm23 may play a tissue-specific role, and that different regulatory mechanisms may act in different tumors. In ovarian carcinoma, nm23-H1/NDP kinase may be correlated with some clinicopathologic characteristics. In cervical cancer, nm23-H1 is probably involved in cervical carcinogenesis and correlated with some aggressive parameters. Overexpression of nm23-H1 protein may indicate poor survival for cervical cancer patients. Other than histidine 118 residue (amino acid sequence 118: histidine) concerned with NDP kinase activity of nm23-H1, serine 120 (amino acid sequence 120: serine) related activity of histidine-dependent protein phosphotransfer was recently reported to be responsible for its biological suppressive effects. To inhibit metastatic potential, nm23-H1 is also demonstrated to co-immunoprecipitate the kinase suppressor of Ras and phosphorylate it, and therefore reduce activation of the extracellular signal-regulated kinase mitogen-activated protein kinase pathway in response to signaling.
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Affiliation(s)
- Yi-Torng Tee
- Department of Obstetrics and Gynecology, Chung Shan Medical University Hospital, Taichung, Taiwan
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21
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Michor F, Iwasa Y. Dynamics of metastasis suppressor gene inactivation. J Theor Biol 2006; 241:676-89. [PMID: 16497335 DOI: 10.1016/j.jtbi.2006.01.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2005] [Accepted: 01/03/2006] [Indexed: 01/18/2023]
Abstract
For most cancer cell types, the acquisition of metastatic ability leads to clinically incurable disease. Twelve metastasis suppressor genes (MSGs) have been identified that reduce the metastatic propensity of cancer cells. If these genes are inactivated in both alleles, metastatic ability is promoted. Here, we develop a mathematical model of the dynamics of MSG inactivation and calculate the expected number of metastases formed by a tumor. We analyse the effects of increased mutation rates and different fitness values of cells with one or two inactivated alleles on the ability of a tumor to form metastases. We find that mutations that are negatively selected in the main tumor are unlikely to be responsible for the majority of metastases produced by a tumor. Most metastases-causing mutations will be present in all (or most) cells in the main tumor.
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Affiliation(s)
- Franziska Michor
- Harvard Society of Fellows, Harvard Program for Evolutionary Dynamics, Cambridge, MA 02138, USA.
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22
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Michor F, Nowak MA, Iwasa Y. Stochastic dynamics of metastasis formation. J Theor Biol 2005; 240:521-30. [PMID: 16343545 DOI: 10.1016/j.jtbi.2005.10.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Revised: 10/17/2005] [Accepted: 10/18/2005] [Indexed: 11/28/2022]
Abstract
Tumor metastasis accounts for the majority of deaths in cancer patients. The metastatic behavior of cancer cells is promoted by mutations in many genes, including activation of oncogenes such as RAS and MYC. Here, we develop a mathematical framework to analyse the dynamics of mutations enabling cells to metastasize. We consider situations in which one mutation is necessary to confer metastatic ability to the cell. We study different population sizes of the main tumor and different somatic fitness values of metastatic cells. We compare mutations that are positively selected in the main tumor with those that are neutral or negatively selected, but faster at forming metastases. We study whether metastatic potential is the property of all (or the majority of) cells in the main tumor or only the property of a small subset. Our theory shows how to calculate the expected number of metastases that are formed by a tumor.
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Affiliation(s)
- Franziska Michor
- Program for Evolutionary Dynamics, Department of Organismic and Evolutionary Biology, Department of Mathematics, Harvard University, Cambridge, MA 02138, USA.
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23
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Cho-Chung YS. Antisense and therapeutic oligonucleotides: toward a gene-targeting cancer clinic. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.10.11.1711] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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24
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Tan ML, Muhammad TST, Najimudin N, Sulaiman SF. Growth arrest and non-apoptotic programmed cell death associated with the up-regulation of c-myc mRNA expression in T-47D breast tumor cells following exposure to Epipremnum pinnatum (L.) Engl. hexane extract. JOURNAL OF ETHNOPHARMACOLOGY 2005; 96:375-383. [PMID: 15619555 DOI: 10.1016/j.jep.2004.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2003] [Revised: 06/16/2004] [Accepted: 07/06/2004] [Indexed: 05/24/2023]
Abstract
Epipremnum pinnatum (L.) Engl. hexane extract produced a significant growth inhibition against T-47D breast carcinoma cells and analysis of cell death mechanisms indicated that the extract elicited a non-apoptotic programmed cell death. T-47D cells exposed to the extract at EC(50) concentration (72 h) for 24 h failed to demonstrate typical DNA fragmentation associated with apoptosis, as carried out using a modified TUNEL assay. In addition, acute exposure to the extract produced an insignificant regulation of caspase-3 and p53 mRNA expression but increased in the c-myc mRNA expression. Ultrastructural analysis using transmission electron microscope demonstrated distinct vacuolated cells, which strongly indicated a Type II non-apoptotic cell death although the changes in chromatin were also detected. The presence of non-apoptotic programmed cell death was then reconfirmed with annexin-V and propidium iodide staining. These findings suggested that up-regulation of c-myc mRNA expression may have contributed to the growth arrest and Type II non-apoptotic programmed cell death in the Epipremnum pinnatum (L.) Engl. hexane extract-treated T-47D cells.
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Affiliation(s)
- M L Tan
- School of Biological Sciences, Universiti Sains Malaysia, 11800 Minden, Pulau Pinang, Malaysia
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25
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Tan ML, Sulaiman SF, Najimuddin N, Samian MR, Muhammad TST. Methanolic extract of Pereskia bleo (Kunth) DC. (Cactaceae) induces apoptosis in breast carcinoma, T47-D cell line. JOURNAL OF ETHNOPHARMACOLOGY 2005; 96:287-94. [PMID: 15588681 DOI: 10.1016/j.jep.2004.09.025] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2003] [Revised: 08/09/2004] [Accepted: 09/13/2004] [Indexed: 05/05/2023]
Abstract
Currently, breast cancer is the leading cause of cancer-related death in women. Therefore, there is an urgent need to develop alternative therapeutic measures against this deadly disease. Here, we report the cytotoxicity activity and the mechanism of cell death exhibited by the methanol extract prepared from Pereskia bleo (Kunth) DC. (Cactaceae) plant against human breast carcinoma cell line, T-47D. In vitro cytotoxicity screening of methanol extract of Pereskia bleo plant indicated the presence of cytotoxicity activity of the extract against T-47D cells with EC50 of 2.0 microg/ml. T-47D cell death elicited by the extract was found to be apoptotic in nature based a clear indication of DNA fragmentation which is a hallmark of apoptosis. In addition, ultrastructural analysis also revealed apoptotic characteristics (the presence of chromatin margination and apoptotic bodies) in the extract-treated cells. RT-PCR analysis showed the mRNA expression levels of c-myc, and caspase 3 were markedly increased in the cells treated with the plant extract. However, p53 expression was only slightly increased as compared to caspase 3 and c-myc. Thus, the results from this study strongly suggest that the methanol extract of Pereskia bleo may contain bioactive compound(s) that caused breast carcinoma, T-47D cell death by apoptosis mechanism via the activation of caspase-3 and c-myc pathways.
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Affiliation(s)
- M L Tan
- School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
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26
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Abstract
Tumour metastasis is a significant contributor to death in cancer patients. Eight metastasis-suppressor genes that reduce the metastatic propensity of a cancer cell line in vivo without affecting its tumorigenicity have been identified. These affect important signal-transduction pathways, including mitogen-activated protein kinases, RHO, RAC and G-protein-coupled and tyrosine-kinase receptors. So how might we use this knowledge to improve the treatment of patients with cancer?
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Affiliation(s)
- Patricia S Steeg
- Women's Cancers Section, Laboratory of Pathology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA.
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27
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Selim AGA, El-Ayat G, Naase M, Wells CA. C-myc oncoprotein expression and gene amplification in apocrine metaplasia and apocrine change within sclerosing adenosis of the breast. Breast 2002; 11:466-72. [PMID: 14965711 DOI: 10.1054/brst.2002.0474] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2002] [Revised: 08/13/2002] [Accepted: 08/21/2002] [Indexed: 11/18/2022] Open
Abstract
Overexpression and/or amplification of c-myc oncogene are known to occur in human breast carcinomas, particularly those of high grade. Apocrine metaplasia (APM) is a common finding within fibrocystic change, and in some cases appears to be associated with an elevated risk of subsequent breast cancer. It has been suggested that apocrine metaplasia within sclerosing adenosis of the breast, also called apocrine adenosis (AA), has a premalignant potential. Little, however, is known about cellular level genetic alterations in either APM or AA of the breast. Because of this, c-myc expression and amplification in APM and AA were studied. Fluorescence in situ hybridisation (FISH) is a methodological approach to detecting these genetic alterations. In this study, APM and AA were studied immunohistochemically to detect c-myc oncoprotein expression, and FISH was employed using a DNA probe for the c-myc gene in archival tissue sections of cases of APM and AA of the breast. Nuclear immunostaining for c-myc was seen in all APM and AA cases studied, but amplification of the c-myc gene was not seen in any cases with APM or AA. The results of this study indicate that c-myc overexpression appears to occur early in breast oncogenesis. Amplification of the c-myc gene does not occur in APM or AA of the breast, however, suggesting that this particular genetic alteration constitutes a late event in the pathogenesis of breast carcinomas.
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Affiliation(s)
- Abdel-Ghani A Selim
- Department of Histopathology, St. Bartholomew's Hospital, St. Bartholomew's and the Royal London School of Medicine and Dentistry, Queen Mary and Westfield College, University of London, West Smithfield, London EC1A 7BE, UK.
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28
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Pereira M, Millot JM, Sebille S, Manfait M. Inhibitory effects of extracellular Mg2+ on intracellular Ca2+ dynamic changes and thapsigargin-induced apoptosis in human cancer MCF7 cells. Mol Cell Biochem 2002; 229:163-71. [PMID: 11936842 DOI: 10.1023/a:1017972622312] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The effects of extracellular Mg2+ on both dynamic changes of [Ca2+]i and apoptosis rate were analysed. The consequences of spatial and temporal dynamic changes of intracellular Ca2+ on apoptosis, in thapsigargin- and the calcium-ionophore 4BrA23187-treated MCF7 cells were first determined. Both 4BrA23187 and thapsigargin induced an instant increase of intracellular Ca2+ concentrations ([Ca2+]i) which remained quite elevated (> 150 nM) and lasted for several hours. [Ca2+]i increases were equivalent in the cytosol and the nucleus. The treatments that induced apoptosis in MCF7 cells were systematically associated with high and sustained [Ca2+]i (150 nM) for several hours. The initial [Ca2+]i increase was not determinant in the events triggering apoptosis. Thapsigargin-mediated apoptosis and [Ca2+]i rise were abrogated when cells were pretreated with the calcium chelator BAPTA. The role of the extracellular Mg2+ concentration has been studied in thapsigargin treated cells. High (10 mM) extracellular Mg2+, caused an increase in basal [Mg2+]i from 0.8+/-0.3 to 1.6+/-0.5 mM. As compared to 1.4 mM extracellular Mg2+, 1 microM thapsigargin induces, in 10 mM Mg2+, a reduced percentage from 22 to 11% of fragmented nuclei, a lower sustained [Ca2+]i and a lower Ca2+ influx through the plasma membrane. In conclusion, the cell death induced by thapsigargin was dependent on high and sustained [Ca2+]i which was inhibited by high extracellular and intracellular Mg2+.
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Affiliation(s)
- Manuella Pereira
- Unité MeDIAN, CNRS FRE 2141, Faculté de Pharmacie, Reims, France
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Samali A, Zhivotovsky B, Orrenius S. Current concepts in cell toxicity. CURRENT PROTOCOLS IN TOXICOLOGY 2001; Chapter 2:Unit 2.1. [PMID: 23045041 DOI: 10.1002/0471140856.tx0201s00] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This overview provides a basic definition of cellular death and the mechanisms that are associated with cell death: apoptosis and necrosis. It includes a description of structural changes and macromolecular degradation and the roles of signaling, mitochondria, and genetic changes in the two forms of cell death.
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Affiliation(s)
- A Samali
- Karolinska Institutet, Stockholm, Sweden
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31
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Crul M, de Klerk GJ, Beijnen JH, Schellens JH. Ras biochemistry and farnesyl transferase inhibitors: a literature survey. Anticancer Drugs 2001; 12:163-84. [PMID: 11290863 DOI: 10.1097/00001813-200103000-00001] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Over the last decades, knowledge on the genetic defects involved in tumor formation and growth has increased rapidly. This has launched the development of novel anticancer agents, interfering with the proteins encoded by the identified mutated genes. One gene of particular interest is ras, which is found mutated at high frequency in a number of malignancies. The Ras protein is involved in signal transduction: it passes on stimuli from extracellular factors to the cell nucleus, thereby changing the expression of a number of growth regulating genes. Mutated Ras proteins remain longer in their active form than normal Ras proteins, resulting in an overstimulation of the proliferative pathway. In order to function, Ras proteins must undergo a series of post-translational modifications, the most important of which is farnesylation. Inhibition of Ras can be accomplished through inhibition of farnesyl transferase, the enzyme responsible for this modification. With this aim, a number of agents, designated farnesyl transferase inhibitors (FTIs), have been developed that possess antineoplastic activity. Several of them have recently entered clinical trials. Even though clinical testing is still at an early stage, antitumor activity has been observed. At the same time, knowledge on the biochemical mechanisms through which these drugs exert their activity is expanding. Apart from Ras, they also target other cellular proteins that require farnesylation to become activated, e.g. RhoB. Inhibition of the farnesylation of RhoB results in growth blockade of the exposed tumor cells as well as an increase in the rate of apoptosis. In conclusion, FTIs present a promising class of anticancer agents, acting through biochemical modulation of the tumor cells.
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Affiliation(s)
- M Crul
- The Netherlands Cancer Institute, Amsterdam, The Netherlands.
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32
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Abstract
The balance between cell survival and death is under tight genetic control. A multiplicity of extracellular signals and intracellular mediators is involved in maintaining this balance. When the cell is exposed to physical, biochemical or biological injury, or deprived of necessary substances, it activates a series of stress-response genes. With minimal insults, the cell may recover. With greater insults, single cell death, or apoptosis, results; the cell dies and is recycled to its neighbours. If the insult overwhelms a large number of cells then necrosis ensues, with an accompanying inflammatory response. Dysregulation of the controlling mechanisms of this system results in disease. Deficient apoptosis is associated with cancer, auto-immunity and viral infections. Excessive apoptosis is associated with ischaemic heart disease, stroke, neurodegenerative disease, sepsis and multiple organ dysfunction syndrome. There are myriad therapeutic options unfolding as understanding is gained of apoptosis and its control.
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Affiliation(s)
- P C Kam
- Department of Anaesthesia and Pain Management, University of Sydney, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
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Abstract
Apoptosis has been well established as a vital biological phenomenon that is important in the maintenance of cellular homeostasis. Three major protooncogene families and their encoded proteins function as mediators of apoptosis in various cell types and are the subject of this chapter. Protooncogenic proteins such as c-Myc/Max, c-Fos/c-Jun, and Bcl-2/Bax utilize a synergetic effect to enhance their roles in the pro- or antiapoptotic action. These family members activate and repress the expression of their target genes, control cell cycle progression, and execute programmed cell death. Repression or overproduction of these protooncogenic proteins induces apoptosis, which may vary as a result of either cell type specificity or the nature of the apoptotic stimuli. The proapoptotic and antiapoptotic proteins exert their effects in the membrane of cellular organelles. Here they generate cell-type-specific signals that activate the caspase family of proteases and their regulators for the execution of apoptosis.
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Affiliation(s)
- C S Teng
- Department of Anatomy, Physiological Sciences, and Radiology, North Carolina State University, Raleigh 27606, USA
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Moon IJ, Lee Y, Kwak CS, Lee JH, Choi K, Schreiber AD, Park JG. Target site search and effective inhibition of leukaemic cell growth by a covalently closed multiple anti-sense oligonucleotide to c-myb. Biochem J 2000; 346 Pt 2:295-303. [PMID: 10677346 PMCID: PMC1220853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Systematic secondary structure simulation of a target mRNA sequence is shown to be effective for locating a good anti-sense target site. Multiple selected anti-sense sequences were placed in a single molecule. The anti-sense oligonucleotide (oligo) was covalently closed to avoid exonuclease activities and was designated CMAS (covalently closed multiple anti-sense)-oligo. CMAS-oligo was found to be stable, largely preserving its structural integrity after 24 h of incubation in the presence of either exonuclease III or serum. When human c-myb mRNA was targeted by the c-myb CMAS-oligo, expression of the gene was completely abolished. Further, tumour cell growth was inhibited by 82+/-3% as determined by an MTT [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay and by 90+/-1% by [(3)H]thymidine incorporation. When a leukaemic cell line K562 was treated with CMAS-oligo, colony formation on soft agarose was also decreased by 93%. In contrast, treatment with a scrambled control oligo did not significantly inhibit leukaemic cell growth. These results suggest that a rational target site search is possible for an anti-sense oligo and that CMAS-oligo can be employed as an effective anti-sense agent with enhanced stability.
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Affiliation(s)
- I J Moon
- Institute for Medical Science, Dongsan Medical Center, Keimyung University, Dongsandong 194, Chunggu, Taegu 700-310, Korea
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Fadeel B, Orrenius S, Zhivotovsky B. Apoptosis in human disease: a new skin for the old ceremony? Biochem Biophys Res Commun 1999; 266:699-717. [PMID: 10603308 DOI: 10.1006/bbrc.1999.1888] [Citation(s) in RCA: 181] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Naturally occurring cell death or apoptosis is essential for the maintenance of tissue homeostasis and serves to remove extraneous or dangerous cells in a swift and unobtrusive manner. Recent studies have indicated a role for apoptosis in a plethora of human diseases. Hence, dysregulation of apoptosis has been implicated in autoimmune disease, acquired immune deficiency syndrome, and other viral (and bacterial) infections, as well as in neurodegenerative disorders and cancer. Furthermore, dysregulated apoptosis signaling may impinge on other age-related disorders such as osteoporosis and atherosclerosis and perhaps on the process of aging itself. The present review provides an overview of human diseases, which are associated with defective or inadvertent apoptosis, with examples of pathological conditions in which putative apoptosis defects have been elucidated at the molecular level. Novel apoptosis-modulating therapeutic strategies are also discussed.
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Affiliation(s)
- B Fadeel
- Institute of Environmental Medicine, Division of Toxicology, Karolinska Institutet, Stockholm, S-171 77, Sweden
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36
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Abstract
Much recent research on c-Myc has focused on how it drives apoptosis. c-Myc is widely known as a crucial regulator of cell proliferation in normal and neoplastic cells, but until relatively recently its apoptotic properties, which appear to be intrinsic, were not fully appreciated. Its death-dealing aspects have gained wide attention in part because of their potential therapeutic utility in advanced malignancy, where c-Myc is frequently deregulated and where novel modalities are badly needed. Although its exact function remains obscure, c-Myc is a transcription factor and advances have been made in characterizing target genes which may mediate its apoptotic properties. Candidate regulators and effectors are also emerging. Among recent findings are connections to the CD95/Fas and TNF pathways and roles for the tumor suppressor p19ARF and the c-Myc-interacting adaptor protein Binl in mediating cell death. In this review I summarize the data establishing a role for c-Myc in apoptosis in diverse settings and present a modified dual signal model for c-Myc function. It is proposed that c-Myc induces apoptosis through separate 'death priming' and 'death triggering' mechanisms in which 'death priming' and mitogenic signals are coordinated. Investigation of the mechanisms that underlie the triggering steps may offer new therapeutic opportunities.
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37
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Hashiramoto A, Sano H, Maekawa T, Kawahito Y, Kimura S, Kusaka Y, Wilder RL, Kato H, Kondo M, Nakajima H. C-myc antisense oligodeoxynucleotides can induce apoptosis and down-regulate Fas expression in rheumatoid synoviocytes. ARTHRITIS AND RHEUMATISM 1999; 42:954-62. [PMID: 10323451 DOI: 10.1002/1529-0131(199905)42:5<954::aid-anr14>3.0.co;2-j] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE To investigate the role of c-myc in the pathogenesis of rheumatoid arthritis (RA) and the mechanism of synovial apoptosis. METHODS Using cultured human synoviocytes from patients with RA and c-myc antisense oligodeoxynucleotides (AS ODN), we examined the inhibition of cell proliferation by the MTT assay and the induction of apoptosis with TUNEL staining and fluorescence microscopy. In addition, the effect of c-myc on down-regulation of Fas expression was analyzed by flow cytometry, cytotoxicity assay, and reverse transcriptase-polymerase chain reaction. RESULTS Treatment with c-myc AS ODN induced inhibition of cell proliferation, along with down-regulation of c-Myc protein and c-myc messenger RNA (mRNA) expression. The morphologic changes of synovial cell death were typical of apoptosis. In addition, c-myc AS ODN treatment down-regulated expression of Fas mRNA but not Fas antigen. Analysis of the involvement of the caspase cascade revealed that the cytotoxic activity of c-myc AS ODN was completely blocked by inhibitors of both caspase 1 (YVAD-FMK) and caspase 3 (DEVD-FMK). CONCLUSION Our results strongly suggest that c-myc AS ODN might be a useful therapeutic tool in RA and clarify that cell death by c-myc AS ODN is induced through the caspase cascade, similar to Fas-induced apoptosis. In addition, combination therapy with anti-Fas antibody and c-myc AS ODN reduced Fas-dependent cytotoxicity.
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39
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Pospelova TV, Medvedev AV, Kukushkin AN, Svetlikova SB, van der Eb AJ, Dorsman JC, Pospelov VA. E1A + cHa-ras transformed rat embryo fibroblast cells are characterized by high and constitutive DNA binding activities of AP-1 dimers with significantly altered composition. Gene Expr 1999; 8:19-32. [PMID: 10543728 PMCID: PMC6157357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/1998] [Accepted: 10/21/1998] [Indexed: 02/14/2023]
Abstract
Transcription factors of the AP-1/ATF family, including c-Fos, c-Jun, and ATF-2, play an important role in the regulation of cell proliferation and differentiation, and changes in their levels and/or activities may contribute to oncogenesis. We analyzed the alterations of AP-1/ATF transcription factors upon immortalization and transformation in a panel of cell lines derived from rat embryo fibroblast (REF) cells. The tumorigenic E1A + cHa-ras cells are characterized by high and constitutive DNA binding activities of AP-1, in contrast to nontransformed cells and the E1A cells. The expression of c-fos and c-jun genes was affected differently by the oncogenic transformation. By using antibodies to c-Jun and c-Fos proteins in electrophoretic mobility shift assays (EMSA), we showed that E1A + cHa-ras transformants did not contain c-Fos under any condition of cell cultivation and growth factor stimulation, whereas c-Jun was constitutively upregulated. In the absence of c-fos gene expression, c-Fos protein appears to be replaced by proteins of Fos family (Fra-1) and ATF family (ATF-2 and ATFa). To determine the possible mechanisms of c-fos downregulation in E1A + cHa-ras transformants we have obtained populations of geneticin-resistant clones containing integrated reporter construct -711fos-CAT and its mutants in serum-responsive element (SRE) and cAMP-responsive element (CRE). Data obtained show that the mutations within the SRE lead to a manifold activation of fos-CAT expression. This allows to suggest that c-fos downregulation in E1A + cHa-ras transformants is provided by a negative control mediated through the SRE regulatory region. The profound differences in regulation and composition of transcription factors of the AP-1 family probably play a pivotal role in the transformation of REF cells by E1A and cHa-ras oncogenes.
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Affiliation(s)
- Tatiana V. Pospelova
- *Institute of Cytology, Russian Academy of Sciences, Tikhoretzky ave., 4, 194064 St-Petersburg, Russia
| | - Alexander V. Medvedev
- *Institute of Cytology, Russian Academy of Sciences, Tikhoretzky ave., 4, 194064 St-Petersburg, Russia
| | - Alexander N. Kukushkin
- *Institute of Cytology, Russian Academy of Sciences, Tikhoretzky ave., 4, 194064 St-Petersburg, Russia
| | - Svetlana B. Svetlikova
- *Institute of Cytology, Russian Academy of Sciences, Tikhoretzky ave., 4, 194064 St-Petersburg, Russia
| | - Alex J. van der Eb
- †Laboratory for Molecular Carcinogenesis, Sylvius Laboratory, Leiden University, Wassenaarseweg 72, 2333 AL, Leiden, The Netherlands
| | - Josephine C. Dorsman
- †Laboratory for Molecular Carcinogenesis, Sylvius Laboratory, Leiden University, Wassenaarseweg 72, 2333 AL, Leiden, The Netherlands
| | - Valery A. Pospelov
- *Institute of Cytology, Russian Academy of Sciences, Tikhoretzky ave., 4, 194064 St-Petersburg, Russia
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40
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Abstract
The MYC proto-oncogene has long been implicated in the control of normal cell growth and its deregulation is associated with the development of neoplasia. The MYC protein has a well-established role as a component of signal-transduction pathways promoting both proliferation and apoptosis. Because signalling pathways that drive cell death and cell proliferation are so tightly coupled, a synergy between genetic lesions leading to suppression of cell death and those promoting cell proliferation is observed during carcinogenesis. We discuss such synergy with respect to the cooperating oncogenes MYC, RAS and BCL2.
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Affiliation(s)
- A O Hueber
- Biochemistry of the Cell Nucleus Laboratory, Imperial Cancer Research Fund, London, UK.
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41
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Abstract
Polyphenolic-glutathione (GSH) conjugates and their metabolites retain the electrophilic and redox properties of the parent polyphenol. Indeed, the reactivity of the thioether metabolites frequently exceeds that of the parent polyphenol. Although the active transport of polyphenolic-GSH conjugates out of the cell in which they are formed will limit their potential toxicity to those cells, once within the circulation they can be transported to tissues that are capable of accumulating these metabolites. There are interesting physiological similarities between the organs that are known to be susceptible to polyphenolic-GSH conjugate-mediated toxicity. In addition, the frequent localization of gamma-glutamyl transpeptidase to cells separating the circulation from a second fluid-filled compartment coincides with tissues that are susceptible either to polyphenolic-GSH conjugate-induced toxicity or to quinone and reactive oxygen species-induced toxicity. Polyphenolic-GSH conjugates therefore contribute to the nephrotoxicity, nephrocarcinogenicity, and neurotoxicity of a variety of polyphenols.
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Affiliation(s)
- T J Monks
- Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas, Austin 78712-1074, USA
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42
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Abstract
Tissue homeostasis requires a balance between cell proliferation and death. Apoptosis and proliferation are linked by cell cycle regulators, and apoptotic stimuli affect both cell proliferation and death. Glucocorticoids induce G1 arrest and apoptosis in transformed lymphoid cells. Decreased expression of the cell cycle components c-myc and cyclin D3 is essential for glucocorticoid-induced growth arrest and death in dividing cells. Other G1 regulators, such as p53, pRb, and E2F, have also been implicated in apoptosis. Mice lacking either p53 or E2F display aberrant cell proliferation and tumor formation, suggesting that these proteins are involved in the elimination of abnormal cells through apoptosis. In contrast, pRb induces G1 arrest and suppresses apoptosis in cultured cells. Mice that lack pRb are nonviable and show ectopic mitosis and massive cell death, suggesting that pRb is an apoptotic suppressor. Further analysis of common components of apoptotic and cell cycle machinery may provide insight into the coordinated regulation of these antagonistic processes.
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Affiliation(s)
- K L King
- Department of Molecular and Cellular Physiology, University of Cincinnati Medical Center, Ohio 45267-0576, USA
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Trudel M, Barisoni L, Lanoix J, D'Agati V. Polycystic kidney disease in SBM transgenic mice: role of c-myc in disease induction and progression. THE AMERICAN JOURNAL OF PATHOLOGY 1998; 152:219-29. [PMID: 9422539 PMCID: PMC1858107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
SBM mouse is a unique transgenic model of polycystic kidney disease (PKD) produced by dysregulation of c-myc in the kidneys. Our previous demonstration that c-myc is overexpressed in human autosomal polycystic kidney disease (ADPKD) prompted us to investigate the pathogenetic role of c-myc in the induction and progression of the cystogenic phenotype in our mouse model. In young SBM kidneys, c-myc was two- to threefold increased with persistent expression levels into adulthood, an age when c-myc is normally undetectable. In situ hybridization analysis of the c-myc transgene demonstrated intense signal specifically overlying glomerular and tubular epithelium of developing cysts in fetal and young kidneys. Increased expression of c-myc correlated with the initiation and progression of the PKD phenotype as evidenced by early tubular and glomerular cysts at E16.5. Cyst number and size increased with age, with co-development of glomerular and tubular epithelial hyperplasia. Consistently, the mean renal proliferative index was increased approximately 5- to 20-fold in noncystic and cystic tubules of newborn SBM animals compared with littermate controls. Similarly, in fetal and newborn kidneys the tubular apoptotic indices were increased approximately three- to ninefold over controls. Both proliferation and apoptotic rates in cystic tubules approached levels in developing tubules from the normal nephrogenic zone. We conclude that the pathogenesis of PKD hinges on a critical imbalance in c-myc regulation of the opposing processes of cell proliferation and apoptosis, recapitulating the cellular phenomena in developing fetal kidney.
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Affiliation(s)
- M Trudel
- Institut de Recherches Cliniques de Montreal, Faculte de Medecine de l'Universite de Montreal, Quebec, Canada.
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44
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Stapleton AM, Zbell P, Kattan MW, Yang G, Wheeler TM, Scardino PT, Thompson TC. Assessment of the biologic markers p53, Ki-67, and apoptotic index as predictive indicators of prostate carcinoma recurrence after surgery. Cancer 1998; 82:168-75. [PMID: 9428494 DOI: 10.1002/(sici)1097-0142(19980101)82:1<168::aid-cncr21>3.0.co;2-#] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND This study was designed to evaluate the potential of the molecular and cellular markers p53, Ki-67, and apoptotic index (AI) as adjuncts to the commonly available variables of tumor grade, clinical stage, and serum prostate specific antigen to predict prostate carcinoma recurrence after radical prostatectomy. METHODS Representative punch biopsy specimens of prostate carcinoma from whole mount paraffin blocks were evaluated from 47 men who underwent radical prostatectomy. Two groups were defined: those without evidence of prostate carcinoma recurrence after 5 years of follow-up (N = 30) and those with carcinoma recurrence (N = 17). Gleason grade, clustered p53 immunostaining, Ki-67 immunostaining, and AI were determined by standard techniques. RESULTS All variables tested were associated with disease recurrence by univariate analysis: AI (P = 0.005), clustered p53 immunostaining (P = 0.0070), and Ki-67 immunostaining (P = 0.0390). Using multivariate analyses that included each biomarker with routinely available features, only AI (P = 0.0234) and clustered p53 immunostaining (P = 0.0389) added independent prognostic information (Ki-67 immunostaining, P = 0.1285). In the final logistic regression model that included standard variables with AI and p53, only AI reached statistical significance (P = 0.0332). CONCLUSIONS The continued assessment of additional biomarkers for prostate carcinoma recurrence is important to identify better those patients who may be candidates for early adjuvant therapy and also to further our understanding of the neoplastic potential of a particular malignancy.
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Affiliation(s)
- A M Stapleton
- The Matsunaga-Conte Prostate Cancer Research Center and the Scott Department of Urology, Baylor College of Medicine, Houston, Texas 77030, USA
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45
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Affiliation(s)
- B V Harmon
- School of Life Science, Queensland University of Technology, Brisbane, Australia
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46
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Snow EC. The role of c-myc during normal B cell proliferation, and as B cells undergo malignant transformation. Curr Top Microbiol Immunol 1997; 224:211-20. [PMID: 9308244 DOI: 10.1007/978-3-642-60801-8_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- E C Snow
- Department of Microbiology and Immunology, University of Kentucky Medical Center, Lexington 40536-0084, USA
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47
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Brenner B, Koppenhoefer U, Weinstock C, Linderkamp O, Lang F, Gulbins E. Fas- or ceramide-induced apoptosis is mediated by a Rac1-regulated activation of Jun N-terminal kinase/p38 kinases and GADD153. J Biol Chem 1997; 272:22173-81. [PMID: 9268362 DOI: 10.1074/jbc.272.35.22173] [Citation(s) in RCA: 257] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In the present study, we show that Fas receptor ligation or cellular treatment with synthetic C6-ceramide results in activation or phosphorylation, respectively, of the small G-protein Rac1, Jun N-terminal kinase (JNK)/p38 kinases (p38-K), and the transcription factor GADD153. A signaling cascade from the Fas receptor via ceramide, Ras, Rac1, and JNK/p38-K to GADD153 is demonstrated employing transfection of transdominant inhibitory N17Ras, N17Rac1, c-Jun, or treatment with a specific p38-K inhibitor. The critical function of this signaling cascade is indicated by prevention of Fas- or C6-ceramide-induced apoptosis after inhibition of Ras, Rac1, or JNK/p38-K.
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Affiliation(s)
- B Brenner
- Department of Pediatrics, University of Heidelberg, INF 150, 69120 Heidelberg, Germany
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48
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Langlois NE, Lamb J, Eremin O, Heys SD. Apoptosis in colorectal carcinoma occurring in patients aged 45 years and under: relationship to prognosis, mitosis, and immunohistochemical demonstration of p53, c-myc and bcl-2 protein products. J Pathol 1997; 182:392-7. [PMID: 9306959 DOI: 10.1002/(sici)1096-9896(199708)182:4<392::aid-path874>3.0.co;2-g] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The aim of this study was to ascertain whether apoptotic counts have prognostic significance in colorectal cancer and if such counts are related to the expression of proteins implicated in cell cycle regulation. Material from a cohort of patients aged 45 years or less with colorectal carcinoma was re-examined to determine apoptotic and mitotic counts by light microscopy, in addition to assessing p53, c-myc, and bcl-2 protein status by immunohistochemistry. The apoptotic index in the 74 patients who were alive or who had died of colorectal carcinoma ranged from 1.2 per cent to 12.3 per cent and exhibited independent prognostic significance, with high counts predicting better survival (P = 0.02). Mitotic counts were not related to survival, despite a close correlation with apoptosis (r = 0.85). Tumours regarded as not staining with the CM1 antibody for p53 protein demonstrated higher apoptotic counts, compared with those that stained (medians 5.2 and 4.0 per cent, respectively; P = 0.03), but p53 expression was found not to be related to survival. The 68 tumours which stained for c-myc appeared to exhibit higher mitotic counts than those that did not. bcl-2 was detected in only four tumours. The latter two proteins exhibited no apparent relationship to the apoptotic index or survival. Although these results indicate a potential role for apoptotic counting in prognostic prediction in colorectal tumours, this is an uncommon group of patients who exhibited some atypical features. The likelihood of a proportion of cases arising within hereditary non-polyposis colorectal cancer syndrome may limit the application of the findings to a more general population with cancer of the colon and rectum. Further work is required, including critical measurement of reproducibility and assessment of the relative impact of this parameter compared with 'traditional' prognostic markers.
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Affiliation(s)
- N E Langlois
- Department of Pathology, University of Aberdeen, Medical School, Foresterhill, U.K
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49
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Wojnowski L, Zimmer AM, Beck TW, Hahn H, Bernal R, Rapp UR, Zimmer A. Endothelial apoptosis in Braf-deficient mice. Nat Genet 1997; 16:293-7. [PMID: 9207797 DOI: 10.1038/ng0797-293] [Citation(s) in RCA: 229] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Tyrosine kinase growth factor receptors and Ras/Raf/MEK/MAPK signalling have been implicated in the suppression as well as augmentation of programmed cell death. In addition, a Ras-independent role for Raf as a suppressor of programmed cell death has been suggested by the recent finding that Craf1 interacts with members of the Bcl-2 family at mitochondrial membranes. However, genetic studies of C. elegans and Drosophila, as well as the targeted mutagenesis of the murine Araf gene, have failed to support such a role. Here we show that mice with a targeted disruption in the Braf gene die of vascular defects during mid-gestation. Braf -/- embryos, unlike Araf -/- or Craf1 -/- embryos (L.W. et al., unpublished), show an increased number of endothelial precursor cells, dramatically enlarged blood vessels and apoptotic death of differentiated endothelial cells. These results establish Braf as a critical signalling factor in the formation of the vascular system and provide the first genetic evidence for an essential role of Raf gene in the regulation of programmed cell death.
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Affiliation(s)
- L Wojnowski
- Section on Genetics, National Institute of Mental Health/National Human Genome Research Institute, Bethesda, Maryland 20892, USA
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50
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Westermann FN, Langlois NE, Simpson JG. Apoptosis in atypical fibroxanthoma and pleomorphic malignant fibrous histiocytoma. Am J Dermatopathol 1997; 19:228-31. [PMID: 9185907 DOI: 10.1097/00000372-199706000-00005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Explanations for the disparate behavior of atypical fibroxanthoma (AFX) as compared with pleomorphic malignant fibrous histiocytoma (MFH) have included the proposition that the former is a pseudosarcoma. Nonetheless, these tumors are now widely regarded as the same process, but with AFX behaving benignly by virtue of its superficial location. However, a neoplasm's metastastatic potential has been proposed to be related to apoptosis. Therefore, the aim of the present study was to examine apoptotic counts, in conjunction with two important regulators of apoptosis: p53 and bcl-2, to determine if a distinction exists that may account for the different outcomes of these lesions. There was no significant statistical difference between eight AFX and nine pleomorphic MFH in terms of apoptotic behavior, proliferative indexes, p53 protein expression, or presence of bcl-2 product. Therefore, our results further support the contention that AFX should be regarded as a form of pleomorphic MFH, which demonstrates low malignant potential by virtue of its location in readily accessible sites.
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