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Patel JR, Gallegos KM, Walker RR, Davidson AM, Davenport I, Tilghman SL. Mammospheres of letrozole-resistant breast cancer cells enhance breast cancer aggressiveness. Oncol Lett 2021; 22:620. [PMID: 34267813 PMCID: PMC8258623 DOI: 10.3892/ol.2021.12881] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 05/11/2021] [Indexed: 12/30/2022] Open
Abstract
Aromatase inhibitors (AIs), such as letrozole, are considered as first-line treatment for estrogen receptor-positive breast cancer in postmenopausal women. Despite the successful use of letrozole, resistance to therapy, tumor relapse and metastasis remain principal causes of patient mortality. Although there is no therapy currently available for AI-resistant breast cancer, previous reports have demonstrated that AI resistance is associated with hormone independence, increased growth factor signaling, enhanced cellular motility and epithelial to mesenchymal transition (EMT). This suggests a convergence of EMT and cancer stem cells (CSCs) in endocrine resistance. The present study evaluated the contribution of mammospheres in letrozole-resistant breast cancer by characterizing mammospheres and their potential impact on cellular motility. Ovariectomized immunocompromised female mice were inoculated in the mammary fat pad with either letrozole-resistant MCF-7 cells (LTLT-Ca) or letrozole-sensitive MCF-7 cells (AC-1). Subsequently, intratumoral CSC marker expression was assessed by immunohistochemistry. The results indicated that LTLT-Ca tumors were CD44+/CD24+, while AC-1 tumors presented low CD44/CD24 expression. Since mammosphere formation depends on CSCs, both cell lines were cultured either adherently (2D) or as mammospheres (3D) to assess the CD44/CD24 protein expression profile. When 3D culturing both cell lines, higher expression levels of CD44 and CD24 were observed when compared with their adherent counterparts, with the most robust change observed in the LTLT-Ca cell line. To quantitate the breast cancer stem cell activity, mammosphere formation assays were performed, and the LTLT-Ca cells formed mammospheres at a 3.4-fold higher index compared with AC-1 cells. Additionally, targeted gene expression arrays were conducted to compare the LTLT-Ca 3D and 2D cells, revealing that LTLT-Ca 3D cells displayed decreased expression levels of genes involved in cell adhesion and tumor suppression (e. g., E-cadherin, caveolin 1 and β-catenin). To validate this finding, wound healing assays were performed, and LTLT-Ca mammospheres exhibited a 70% wound closure, whereas AC-1 mammospheres exhibited a 39% wound closure. Collectively, the present findings demonstrated a strong association between AI-resistant mammospheres and an increased propensity for migration, which may be indicative of a poor prognosis.
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Affiliation(s)
- Jankiben R. Patel
- Division of Basic Sciences, College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA
| | - Karen M. Gallegos
- Division of Basic Sciences, College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA
| | - Rashidra R. Walker
- Division of Basic Sciences, College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA
| | - A. Michael Davidson
- Division of Basic Sciences, College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA
| | - Ian Davenport
- Division of Biological and Public Health Sciences, Department of Biology, College of Arts and Sciences, Xavier University of Louisiana, New Orleans, LA 70125, USA
| | - Syreeta L. Tilghman
- Division of Basic Sciences, College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, FL 32307, USA
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Frequent genetic defects in the p16/INK4A tumor suppressor in canine cell models of breast cancer and melanoma. In Vitro Cell Dev Biol Anim 2021; 57:519-530. [PMID: 34014456 DOI: 10.1007/s11626-021-00571-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 03/29/2021] [Indexed: 10/21/2022]
Abstract
The cyclin-dependent kinase inhibitors (CKIs) belong to a group of key cell cycle proteins that regulate important cancer drug targets such as the cyclin/CDK complexes. Gene defects in the INK4A/B CKI tumor suppressor locus are frequently associated with human cancers and we have previously identified similar defects in canine models. Many of the cancer-associated genetic alterations, known to play roles in mammary tumor development and progression, appear similar in humans and dogs. The objectives of this study were to characterize expression defects in the INK4 genes, and the encoded p16 family proteins, in spontaneous canine primary mammary tumors (CMT) as well as in canine malignant melanoma (CML) cell lines to further develop these models of spontaneous cancers. Gene expression profiles and characterization of p16 protein were performed by rtPCR assay and immunoblotting followed by an analysis of relevant sequences with bioinformatics. The INK4 gene family were expressed differentially and the genes encoding the tumor suppressor p16, p14, and p15 proteins were often identified as defective in CMT and CML cell lines. The altered expression profiles for INK4 locus encoded tumor suppressor genes was also confirmed by the identification of similar gene defects in primary canine mammary tumor biopsy specimens which were also comparable to defects found in human breast cancer. These data strongly suggest that defects identified in the INK4 locus in canine cell lines are lesions originating in spontaneous canine cancers and are not the product of selection in culture. These findings further validate canine tumor models for use in developing a clear understanding of the gene defects present and may help identify new therapeutic cancer treatments that restore these tumor suppressor pathways based on precision medicine in canine cancers.
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Zhang HW, Wang F, Zhou YQ, Xu SP, Yu SY, Zhang ZG. Morphine Suppresses Liver Cancer Cell Tumor Properties In Vitro and In Vivo. Front Oncol 2021; 11:666446. [PMID: 33968773 PMCID: PMC8100596 DOI: 10.3389/fonc.2021.666446] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 04/06/2021] [Indexed: 11/13/2022] Open
Abstract
Morphine is an analgesic widely adopted to relieve cancer pain. A number of discrepancies, however, are presented by the published literature, with reports suggesting that opioids may either promote or inhibit the spread of cancer. It is of great significance to determine whether morphine may increase the risk of metastasis while utilized in liver cancer surgical treatment. In this study, we explore the effects of morphine on liver cancer cells in vitro and in vivo. Our results showed that morphine does not promote proliferative ability to cultured liver cancer cells. While morphine could increase the apoptosis rate of Hep3B/HepG2 cells. Furthermore, morphine could significantly inhibit the migratory and invasion ability of Hep3B/HepG2 cells. Subsequent investigations disclosed that morphine could inhibit sphere formation ability of Hep3B/HepG2 cells by using sphere formation assay. Based on nude mouse models, we demonstrated that morphine significantly reduced pulmonary tumorigenicity of Hep3B/HepG2 cells. In conclusion, our results found that morphine at clinical concentrations could suppress liver cancer cell tumor properties in vitro and in vivo, indicating the safety of morphine utilization in HCC patients' pain management.
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Affiliation(s)
- Hao-Wen Zhang
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fei Wang
- School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ya-Qun Zhou
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - San-Ping Xu
- Health Management Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shi-Ying Yu
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhan-Guo Zhang
- Hepatic Surgery Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Dominant role of CDKN2B/p15INK4B of 9p21.3 tumor suppressor hub in inhibition of cell-cycle and glycolysis. Nat Commun 2021; 12:2047. [PMID: 33824349 PMCID: PMC8024281 DOI: 10.1038/s41467-021-22327-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 03/11/2021] [Indexed: 01/07/2023] Open
Abstract
Human chromosome 9p21.3 is susceptible to inactivation in cell immortalization and diseases, such as cancer, coronary artery disease and type-2 diabetes. Although this locus encodes three cyclin-dependent kinase (CDK) inhibitors (p15INK4B, p14ARF and p16INK4A), our understanding of their functions and modes of action is limited to the latter two. Here, we show that in vitro p15INK4B is markedly stronger than p16INK4A in inhibiting pRb1 phosphorylation, E2F activity and cell-cycle progression. In mice, urothelial cells expressing oncogenic HRas and lacking p15INK4B, but not those expressing HRas and lacking p16INK4A, develop early-onset bladder tumors. The potency of CDKN2B/p15INK4B in tumor suppression relies on its strong binding via key N-terminal residues to and inhibition of CDK4/CDK6. p15INK4B also binds and inhibits enolase-1, a glycolytic enzyme upregulated in most cancer types. Our results highlight the dual inhibition of p15INK4B on cell proliferation, and unveil mechanisms whereby p15INK4B aberrations may underpin cancer and non-cancer conditions. The human chromosome locus 9p21.3 is a tumour suppressor hub which encodes three CDK inhibitors, p15INK4B, p14ARF and p16INK4A. Here, the authors show that p15INK4B inhibits the cell cycle and glycolysis in a murine model of HRas + ‐mediated urothelial carcinoma and has a more relevant role as a tumour suppressor than its neighbouring p16INK4A.
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Senescence under appraisal: hopes and challenges revisited. Cell Mol Life Sci 2021; 78:3333-3354. [PMID: 33439271 PMCID: PMC8038995 DOI: 10.1007/s00018-020-03746-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 11/20/2020] [Accepted: 12/17/2020] [Indexed: 02/06/2023]
Abstract
In recent years, cellular senescence has become the focus of attention in multiple areas of biomedical research. Typically defined as an irreversible cell cycle arrest accompanied by increased cellular growth, metabolic activity and by a characteristic messaging secretome, cellular senescence can impact on multiple physiological and pathological processes such as wound healing, fibrosis, cancer and ageing. These unjustly called 'zombie cells' are indeed a rich source of opportunities for innovative therapeutic development. In this review, we collate the current understanding of the process of cellular senescence and its two-faced nature, i.e. beneficial/detrimental, and reason this duality is linked to contextual aspects. We propose the senescence programme as an endogenous pro-resolving mechanism that may lead to sustained inflammation and damage when dysregulated or when senescent cells are not cleared efficiently. This pro-resolving model reconciles the paradoxical two faces of senescence by emphasising that it is the unsuccessful completion of the programme, and not senescence itself, what leads to pathology. Thus, pro-senescence therapies under the right context, may favour inflammation resolution. We also review the evidence for the multiple therapeutic approaches under development based on senescence, including its induction, prevention, clearance and the use of senolytic and senomorphic drugs. In particular, we highlight the importance of the immune system in the favourable outcome of senescence and the implications of an inefficient immune surveillance in completion of the senescent cycle. Finally, we identify and discuss a number of challenges and existing gaps to encourage and stimulate further research in this exciting and unravelled field, with the hope of promoting and accelerating the clinical success of senescence-based therapies.
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Neja SA. Site-Specific DNA Demethylation as a Potential Target for Cancer Epigenetic Therapy. Epigenet Insights 2020; 13:2516865720964808. [PMID: 35036833 PMCID: PMC8756105 DOI: 10.1177/2516865720964808] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 09/13/2020] [Indexed: 12/13/2022] Open
Abstract
Aberrant promoter DNA hypermethylation is a typical characteristic of cancer and it is often seen in malignancies. Recent studies showed that regulatory cis-elements found up-stream of many tumor suppressor gene promoter CpG island (CGI) attract DNA methyltransferases (DNMT) that hypermethylates and silence the genes. As epigenetic alterations are potentially reversible, they make attractive targets for therapeutic intervention. The currently used decitabine (DAC) and azacitidine (AZA) are DNMT inhibitors that follow the passive demethylation pathway. However, they lead to genome-wide demethylation of CpGs in cells, which makes difficult to use it for causal effect analysis and treatment of specific epimutations. Demethylation through specific demethylase enzymes is thus critical for epigenetic resetting of silenced genes and modified chromatins. Yet DNA-binding factors likely play a major role to guide the candidate demethylase enzymes upon its fusion. Before the advent of clustered regulatory interspaced short palindromic repeats (CRISPR), both zinc finger proteins (ZNFs) and transcription activator-like effector protein (TALEs) were used as binding platforms for ten-eleven translocation (TET) enzymes and both systems were able to induce transcription at targeted loci in an in vitro as well as in vivo model. Consequently, the development of site-specific and active demethylation molecular trackers becomes more than hypothetical to makes a big difference in the treatment of cancer in the future. This review is thus to recap the novel albeit distinct studies on the potential use of site-specific demethylation for the development of epigenetic based cancer therapy.
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Della-Fazia MA, Castelli M, Piobbico D, Pieroni S, Servillo G. The Ins and Outs of HOPS/TMUB1 in biology and pathology. FEBS J 2020; 288:2773-2783. [PMID: 32860479 DOI: 10.1111/febs.15539] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/28/2020] [Accepted: 08/24/2020] [Indexed: 12/12/2022]
Abstract
Liver regeneration represents an outstanding tool to study not only proliferation, but also other important processes such as inflammation, regenerative response or stem cell biology. Several novel genes have been identified as being involved in the proliferation of residual hepatocytes. One of them, HOPS/TMUB1, is proving to be a significant player in the control of proliferation, both contributing to genomic stability and as a partner of essential molecules. HOPS is an ubiquitin-like protein, shuttling from nucleus to cytoplasm, and it is engaged in a number of biological and physiopathological functions. HOPS overexpression in tumour cell lines strongly reduces proliferation, arresting cell cycle in G0 /G1 . HOPS is involved in centrosome assembly and maintenance, and its knockdown causes genomic instability. Moreover, a direct interaction of HOPS with nucleophosmin (NPM) and p19Arf has been established, resulting in proper control of p19Arf stability and localization. These data indicate that HOPS acts as a functional bridge in the interaction between NPM and p19Arf , providing new mechanistic insight into how NPM and p19Arf will oppose cell proliferation. HOPS exerts a control in p53 stability, directing p53 mitochondrial apoptosis and cytoplasmic localization. HOPS plays a direct role as novel post-translational modifier of p53, much like SUMO or NEDD. HOPS is overexpressed in a high number of human tumours in patients affected by large intestinal, CNS, liver and oesophageal tumours. This review highlights HOPS involvement in distinct cellular functions, establishing its role as a key player in cell biology and pathology in a broader context.
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Affiliation(s)
| | | | - Danilo Piobbico
- Department of Experimental Medicine, University of Perugia, Italy
| | - Stefania Pieroni
- Department of Experimental Medicine, University of Perugia, Italy
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Chaney KE, Perrino MR, Kershner LJ, Patel AV, Wu J, Choi K, Rizvi TA, Dombi E, Szabo S, Largaespada DA, Ratner N. Cdkn2a Loss in a Model of Neurofibroma Demonstrates Stepwise Tumor Progression to Atypical Neurofibroma and MPNST. Cancer Res 2020; 80:4720-4730. [PMID: 32816910 DOI: 10.1158/0008-5472.can-19-1429] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 05/06/2020] [Accepted: 08/13/2020] [Indexed: 02/06/2023]
Abstract
Plexiform neurofibromas are benign nerve sheath Schwann cell tumors characterized by biallelic mutations in the neurofibromatosis type 1 (NF1) tumor suppressor gene. Atypical neurofibromas show additional frequent loss of CDKN2A/Ink4a/Arf and may be precursor lesions of aggressive malignant peripheral nerve sheath tumors (MPNST). Here we combined loss of Nf1 in developing Schwann cells with global Ink4a/Arf loss and identified paraspinal plexiform neurofibromas and atypical neurofibromas. Upon transplantation, atypical neurofibromas generated genetically engineered mice (GEM)-PNST similar to human MPNST, and tumors showed reduced p16INK4a protein and reduced senescence markers, confirming susceptibility to transformation. Superficial GEM-PNST contained regions of nerve-associated plexiform neurofibromas or atypical neurofibromas and grew rapidly on transplantation. Transcriptome analyses showed similarities to corresponding human tumors. Thus, we recapitulated nerve tumor progression in NF1 and provided preclinical platforms for testing therapies at each tumor grade. These results support a tumor progression model in which loss of NF1 in Schwann cells drives plexiform neurofibromas formation, additional loss of Ink4a/Arf contributes to atypical neurofibromas formation, and further changes underlie transformation to MPNST. SIGNIFICANCE: New mouse models recapitulate the stepwise progression of NF1 tumors and will be useful to define effective treatments that halt tumor growth and tumor progression in NF1.
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Affiliation(s)
- Katherine E Chaney
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio
| | - Melissa R Perrino
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio
| | - Leah J Kershner
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio
| | - Ami V Patel
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio
| | - Jianqiang Wu
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio
| | - Kwangmin Choi
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio
| | - Tilat A Rizvi
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio
| | - Eva Dombi
- Center for Cancer Research, National Cancer Institute, Bethesda, Maryland
| | - Sara Szabo
- Department of Pediatrics and Department of Pediatric Pathology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio
| | - David A Largaespada
- Departments of Pediatrics and Genetics, Cell Biology and Development, Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Nancy Ratner
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio.
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Saito M, Okumura K, Isogai E, Araki K, Tanikawa C, Matsuda K, Kamijo T, Kominami R, Wakabayashi Y. A Polymorphic Variant in p19 Arf Confers Resistance to Chemically Induced Skin Tumors by Activating the p53 Pathway. J Invest Dermatol 2019; 139:1459-1469. [PMID: 30684556 DOI: 10.1016/j.jid.2018.12.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/27/2018] [Accepted: 12/28/2018] [Indexed: 12/14/2022]
Abstract
Identification of the specific genetic variants responsible for the increased susceptibility to familial or sporadic cancers is important. Using a forward genetics approach to map such loci in a mouse skin cancer model, we previously identified a strong genetic locus, Stmm3, conferring resistance to chemically induced skin papillomas on chromosome 4. Here, we report the cyclin-dependent kinase inhibitor gene Cdkn2a/p19Arf as a major responsible gene for the Stmm3 locus. We provide evidence that the function of Stmm3 is dependent on p53 and that p19ArfMSM confers stronger resistance to papillomas than p16Ink4aMSMin vivo. In addition, we found that genetic polymorphism in p19Arf between a resistant strain, MSM/Ms (Val), and a susceptible strain, FVB/N (Leu), alters the susceptibility to papilloma development, malignant conversion, and the epithelial-mesenchymal transition. Moreover, we demonstrated that the p19ArfMSM allele more efficiently activates the p53 pathway than the p19ArfFVB allele in vitro and in vivo. Furthermore, we found polymorphisms in CDKN2A in the vicinity of a polymorphism in mouse Cdkn2a associated with the risk of human cancers in the Japanese population. Genetic polymorphisms in Cdkn2a and CDKN2A may affect the cancer risk in both mice and humans.
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Affiliation(s)
- Megumi Saito
- Department of Carcinogenesis Research, Division of Experimental Animal Research, Chiba Cancer Center Research Institute, Chiba, Japan
| | - Kazuhiro Okumura
- Department of Carcinogenesis Research, Division of Experimental Animal Research, Chiba Cancer Center Research Institute, Chiba, Japan
| | - Eriko Isogai
- Department of Carcinogenesis Research, Division of Experimental Animal Research, Chiba Cancer Center Research Institute, Chiba, Japan
| | - Kimi Araki
- Division of Developmental Genetics, Institute of Resource Development and Analysis, Kumamoto, Japan
| | - Chizu Tanikawa
- Laboratory of Genome Technology, Human Genome Center, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Koichi Matsuda
- Laboratory of Genome Technology, Human Genome Center, Institute of Medical Science, University of Tokyo, Tokyo, Japan; Laboratory of Clinical Genome Sequencing, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Tokyo, Japan
| | - Takehiko Kamijo
- Research Institute for Clinical Oncology, Saitama Cancer Center, Saitama, Japan
| | - Ryo Kominami
- Department of Molecular Physiology, Niigata University School of Medicine, Niigata, Japan
| | - Yuichi Wakabayashi
- Department of Carcinogenesis Research, Division of Experimental Animal Research, Chiba Cancer Center Research Institute, Chiba, Japan.
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Wu CH, Chuang HY, Wang CL, Hsu CY, Long CY, Hsieh TH, Tsai EM. Estradiol induces cell proliferation in MCF‑7 mammospheres through HER2/COX‑2. Mol Med Rep 2019; 19:2341-2349. [PMID: 30664162 DOI: 10.3892/mmr.2019.9879] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 10/02/2018] [Indexed: 11/06/2022] Open
Abstract
Cluster of differentiation (CD)44+/CD24- breast cancer cells have stem cell‑like characteristics and are potent initiators of tumorigenesis. Mammosphere cells can partially initiate breast tumorigenesis by inducing estradiol (E2)‑dependent breast cancer cells. However, the mechanisms by which E2 mediates cancer formation in MCF‑7 mammosphere (MS) cells have remained elusive. In the present study, MS cells were isolated by sphere culture. It was possible to maintain these MS cells in culture for long periods of time, while retaining the CD44+/CD24- stem cell marker status. The CD44+/CD24- status was confirmed by flow cytometry. Furthermore, the stem‑cell markers Musashi‑1, cytokeratin (CK)7 and CK19 were identified by immunofluorescence microscopy. It was revealed that treatment of MS cells with E2 increased the expression of CD44, whereas decreased the expression of CD24 on MS cells. In addition, treatment with E2 increased colony formation by MS cells. E2 also induced cyclooxygenase‑2 (COX‑2) expression in MS cells, which promoted their proliferation through the estrogen receptor/human epidermal growth factor receptor 2 (HER2)/mitogen‑activated protein kinase/phosphoinositide‑3 kinase signaling pathway. The results suggested a tumorigenic mechanism by which E2 promotes tumor cell proliferation via HER2/COX‑2 signaling. The present study provided evidence for the molecular impact of E2 on breast tumorigenesis, and suggested possible strategies for preventing and treating human breast cancer.
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Affiliation(s)
- Chin-Hu Wu
- Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Sanmin, Kaohsiung 807, Taiwan R.O.C
| | - Hui-Yu Chuang
- Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Sanmin, Kaohsiung 807, Taiwan R.O.C
| | - Chiu-Lin Wang
- Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Sanmin, Kaohsiung 807, Taiwan R.O.C
| | - Chia-Yi Hsu
- Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Sanmin, Kaohsiung 807, Taiwan R.O.C
| | - Cheng-Yu Long
- Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Sanmin, Kaohsiung 807, Taiwan R.O.C
| | - Tsung-Hua Hsieh
- Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Sanmin, Kaohsiung 807, Taiwan R.O.C
| | - Eing-Mei Tsai
- Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Sanmin, Kaohsiung 807, Taiwan R.O.C
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Bertz S, Eckstein M, Stoehr R, Weyerer V, Hartmann A. Urothelial Bladder Cancer: An Update on Molecular Pathology with Clinical Implications. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.eursup.2017.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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12
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De Jaime-Soguero A, Aulicino F, Ertaylan G, Griego A, Cerrato A, Tallam A, del Sol A, Cosma MP, Lluis F. Wnt/Tcf1 pathway restricts embryonic stem cell cycle through activation of the Ink4/Arf locus. PLoS Genet 2017; 13:e1006682. [PMID: 28346462 PMCID: PMC5386305 DOI: 10.1371/journal.pgen.1006682] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 04/10/2017] [Accepted: 03/10/2017] [Indexed: 12/22/2022] Open
Abstract
Understanding the mechanisms regulating cell cycle, proliferation and potency of pluripotent stem cells guarantees their safe use in the clinic. Embryonic stem cells (ESCs) present a fast cell cycle with a short G1 phase. This is due to the lack of expression of cell cycle inhibitors, which ultimately determines naïve pluripotency by holding back differentiation. The canonical Wnt/β-catenin pathway controls mESC pluripotency via the Wnt-effector Tcf3. However, if the activity of the Wnt/β-catenin controls the cell cycle of mESCs remains unknown. Here we show that the Wnt-effector Tcf1 is recruited to and triggers transcription of the Ink4/Arf tumor suppressor locus. Thereby, the activation of the Wnt pathway, a known mitogenic pathway in somatic tissues, restores G1 phase and drastically reduces proliferation of mESCs without perturbing pluripotency. Tcf1, but not Tcf3, is recruited to a palindromic motif enriched in the promoter of cell cycle repressor genes, such as p15Ink4b, p16Ink4a and p19Arf, which mediate the Wnt-dependent anti-proliferative effect in mESCs. Consistently, ablation of β-catenin or Tcf1 expression impairs Wnt-dependent cell cycle regulation. All together, here we showed that Wnt signaling controls mESC pluripotency and proliferation through non-overlapping functions of distinct Tcf factors. Studying how to safely expand stem cells in culture is essential for regenerative medicine applications. Hence there is a clear need to decode how the cell cycle of mouse embryonic stem cells (mESCs) is regulated. Tcf3 and Tcf1 belong to the Tcf family of proteins. Tcf/Lef are effectors of the Wnt/β-catenin pathway and Tcf3 controls mESC pluripotency. Here we identified a recruitment site for Tcf1 embedded into a number of cell cycle repressor genes such as p15Ink4b, p16Ink4a and p19Arf. Tcf1-mediated activation of these genes drastically slows down proliferation of mESCs. In conclusion, here we showed that the Wnt pathway, besides controlling mESC pluripotency via Tcf3, also regulates mESC cell cycle through the recruitment of Tcf1 to the regulatory sites of key cell cycle genes.
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Affiliation(s)
- Anchel De Jaime-Soguero
- KU Leuven Stem Cell Institute, Department of Development and Regeneration, Stem Cell Signalling laboratory, Herestraat 49, Onderwijs en Navorsing 4, Leuven, Belgium
| | - Francesco Aulicino
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, Spain
| | - Gokhan Ertaylan
- Maastricht Centre for Systems Biology (MaCSBio), Maastricht University. Universiteitssingel 60, 6229 ER Maastricht, The Netherlands
| | - Anna Griego
- KU Leuven Stem Cell Institute, Department of Development and Regeneration, Stem Cell Signalling laboratory, Herestraat 49, Onderwijs en Navorsing 4, Leuven, Belgium
| | - Aniello Cerrato
- Istituto per l'Endocrinologia e l'Oncologia Sperimentale "Gaetano Salvatore", CNR, Napoli, Italy
| | - Aravind Tallam
- TWINCORE, Zentrum für Experimentelle und Klinische Infektionsforschung, Hannover, Germany
| | - Antonio del Sol
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, 7, Avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette, Luxembourg
| | - Maria Pia Cosma
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Dr Aiguader 88, Barcelona, Spain
- ICREA, Pg. Lluís Companys 23, Barcelona, Spain
- * E-mail: ;
| | - Frederic Lluis
- KU Leuven Stem Cell Institute, Department of Development and Regeneration, Stem Cell Signalling laboratory, Herestraat 49, Onderwijs en Navorsing 4, Leuven, Belgium
- * E-mail: ;
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13
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Morphine promotes cancer stem cell properties, contributing to chemoresistance in breast cancer. Oncotarget 2016; 6:3963-76. [PMID: 25686831 PMCID: PMC4414166 DOI: 10.18632/oncotarget.2894] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Accepted: 12/11/2014] [Indexed: 01/24/2023] Open
Abstract
Morphine is an opioid analgesic drug commonly used for pain relief in cancer patients. Here, we report that morphine enhances the mammosphere forming capacity and increases the expression of stemness-related transcription factors Oct4, Sox2 and Nanog. Treatment with morphine leads to enrichment of a side population fraction in MCF-7 cells and the CD44+/CD24−/low population in BT549 cells. Consistently, morphine activates Wnt/β-catenin signaling to induce epithelial to mesenchymal transition and promotes metastasis. Moreover, morphine decreases the sensitivity of traditional anti-cancer drugs in breast cancer cells. Nalmefene, an antagonist of morphine, reverses morphine-induced cancer stem cell properties and chemoresistance in breast cancer. In addition, nalmefene abolishes morphine enhancing tumorigenesis in a NOD/SCID mouse model. In conclusion, our findings demonstrate that morphine contributes to chemoresistance via expanding the population of cancer stem cells and promotes tumor growth, thereby revealing a novel role of morphine and providing some new guides in clinical use of morphine.
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Lutful Kabir FM, Alvarez CE, Bird RC. Canine Mammary Carcinomas: A Comparative Analysis of Altered Gene Expression. Vet Sci 2015; 3:vetsci3010001. [PMID: 29056711 PMCID: PMC5644615 DOI: 10.3390/vetsci3010001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 11/19/2015] [Accepted: 12/21/2015] [Indexed: 12/19/2022] Open
Abstract
Breast cancer represents the second most frequent neoplasm in humans and sexually intact female dogs after lung and skin cancers, respectively. Many similar features in human and dog cancers including, spontaneous development, clinical presentation, tumor heterogeneity, disease progression and response to conventional therapies have supported development of this comparative model as an alternative to mice. The highly conserved similarities between canine and human genomes are also key to this comparative analysis, especially when compared to the murine genome. Studies with canine mammary tumor (CMT) models have shown a strong genetic correlation with their human counterparts, particularly in terms of altered expression profiles of cell cycle regulatory genes, tumor suppressor and oncogenes and also a large group of non-coding RNAs or microRNAs (miRNAs). Because CMTs are considered predictive intermediate models for human breast cancer, similarities in genetic alterations and cancer predisposition between humans and dogs have raised further interest. Many cancer-associated genetic defects critical to mammary tumor development and oncogenic determinants of metastasis have been reported and appear to be similar in both species. Comparative analysis of deregulated gene sets or cancer signaling pathways has shown that a significant proportion of orthologous genes are comparably up- or down-regulated in both human and dog breast tumors. Particularly, a group of cell cycle regulators called cyclin-dependent kinase inhibitors (CKIs) acting as potent tumor suppressors are frequently defective in CMTs. Interestingly, comparative analysis of coding sequences has also shown that these genes are highly conserved in mammals in terms of their evolutionary divergence from a common ancestor. Moreover, co-deletion and/or homozygous loss of the INK4A/ARF/INK4B (CDKN2A/B) locus, encoding three members of the CKI tumor suppressor gene families (p16/INK4A, p14ARF and p15/INK4B), in many human and dog cancers including mammary carcinomas, suggested their important conserved genetic order and localization in orthologous chromosomal regions. miRNAs, as powerful post-transcriptional regulators of most of the cancer-associated genes, have not been well evaluated to date in animal cancer models. Comprehensive expression profiles of miRNAs in CMTs have revealed their altered regulation showing a strong correlation with those found in human breast cancers. These genetic correlations between human and dog mammary cancers will greatly advance our understanding of regulatory mechanisms involving many critical cancer-associated genes that promote neoplasia and contribute to the promising development of future therapeutics.
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Affiliation(s)
- Farruk M Lutful Kabir
- Auburn University Research Initiative in Cancer (AURIC), Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849, USA.
- Current address: Department of Pediatrics, Division of Pulmonology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Carlos E Alvarez
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children's Hospital Departments of Pediatrics and Veterinary Clinical Sciences, The Ohio State University Colleges of Medicine and Veterinary Medicine, Columbus, OH 43205, USA.
| | - R Curtis Bird
- Auburn University Research Initiative in Cancer (AURIC), Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849, USA.
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15
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Wang Z, Chen CC, Chen W. CD150(-) Side Population Defines Leukemia Stem Cells in a BALB/c Mouse Model of CML and Is Depleted by Genetic Loss of SIRT1. Stem Cells 2015; 33:3437-51. [PMID: 26466808 DOI: 10.1002/stem.2218] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 08/12/2015] [Accepted: 09/02/2015] [Indexed: 11/11/2022]
Abstract
Leukemia stem cells (LSCs) of chronic myeloid leukemia (CML) are refractory to tyrosine kinase inhibitor treatment, persist in the residual disease, and are important source for disease recurrence. Better understanding CML LSCs will help devise new strategies to eradicate these cells. The BALB/c mouse model of CML using retroviral bone marrow transduction and transplantation is a widely used mouse model system for CML, but LSCs in this model are poorly characterized. Here, we show that lineage negative CD150(-) side population (CD150(-)SP), but not CD150(+)SP, are CML LSCs in this model, although both CD150(-)SP and CD150(+)SP cells are enriched for long-term hematopoietic stem cells in normal BALB/c mice. We previously showed that BCR-ABL transformation activates protein lysine deacetylase SIRT1 and inhibition of SIRT1 sensitizes CML stem/progenitor cells to tyrosine kinase inhibitors by acetylating and activating p53. In this study, we demonstrate that SIRT1 homozygous knockout substantially reduces CD150(-)SP CML LSCs, and compromises the maintenance of CML LSCs in the BALB/c model. We identified several molecular alterations in CD150(-)SP LSCs that included the elevated expression of cyclin-dependent kinase Cdk6 facilitating LSC activation and significantly reduced p53 expression. SIRT1 knockout suppressed Cdk6 expression and likely increases p53 protein functions through deacetylation without increasing its expression. Our results shed novel insight into CML LSCs and support a crucial role of SIRT1 in CML LSCs. Our study also provides a novel means for assessing new agents to eradicate CML LSCs.
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Affiliation(s)
- Zhiqiang Wang
- Department of Cancer Biology, Beckman Research Institute, City of Hope, Duarte, California, USA
| | - Ching-Cheng Chen
- Division of Hematopoietic Stem Cell and Leukemia Research, Beckman Research Institute, City of Hope, Duarte, California, USA
| | - WenYong Chen
- Department of Cancer Biology, Beckman Research Institute, City of Hope, Duarte, California, USA
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16
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Knowles MA, Hurst CD. Molecular biology of bladder cancer: new insights into pathogenesis and clinical diversity. Nat Rev Cancer 2015; 15:25-41. [PMID: 25533674 DOI: 10.1038/nrc3817] [Citation(s) in RCA: 804] [Impact Index Per Article: 89.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Urothelial carcinoma of the bladder comprises two long-recognized disease entities with distinct molecular features and clinical outcome. Low-grade non-muscle-invasive tumours recur frequently but rarely progress to muscle invasion, whereas muscle-invasive tumours are usually diagnosed de novo and frequently metastasize. Recent genome-wide expression and sequencing studies identify genes and pathways that are key drivers of urothelial cancer and reveal a more complex picture with multiple molecular subclasses that traverse conventional grade and stage groupings. This improved understanding of molecular features, disease pathogenesis and heterogeneity provides new opportunities for prognostic application, disease monitoring and personalized therapy.
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Affiliation(s)
- Margaret A Knowles
- Section of Experimental Oncology, Leeds Institute of Cancer and Pathology, St James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK
| | - Carolyn D Hurst
- Section of Experimental Oncology, Leeds Institute of Cancer and Pathology, St James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK
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17
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Scelfo A, Piunti A, Pasini D. The controversial role of the Polycomb group proteins in transcription and cancer: how much do we not understand Polycomb proteins? FEBS J 2014; 282:1703-22. [PMID: 25315766 DOI: 10.1111/febs.13112] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/03/2014] [Accepted: 10/14/2014] [Indexed: 12/21/2022]
Abstract
Polycomb group proteins (PcGs) are a large protein family that includes diverse biochemical features assembled together in two large multiprotein complexes. These complexes maintain gene transcriptional repression in a cell type specific manner by modifying the surrounding chromatin to control development, differentiation and cell proliferation. PcGs are also involved in several diseases. PcGs are often directly or indirectly implicated in cancer development for which they have been proposed as potential targets for cancer therapeutic strategies. However, in the last few years a series of discoveries about the basic properties of PcGs and the identification of specific genetic alterations affecting specific Polycomb proteins in different tumours have converged to challenge old dogmas about PcG biological and molecular functions. In this review, we analyse these new data in the context of the old knowledge, highlighting the controversies and providing new models of interpretation and ideas that will perhaps bring some order among apparently contradicting observations.
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Affiliation(s)
- Andrea Scelfo
- Department of Experimental Oncology, European Institute of Oncology, Milan, Italy
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18
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Min EY, Kim IH, Lee J, Kim EY, Choi YH, Nam TJ. The effects of fucodian on senescence are controlled by the p16INK4a-pRb and p14Arf-p53 pathways in hepatocellular carcinoma and hepatic cell lines. Int J Oncol 2014; 45:47-56. [PMID: 24807532 PMCID: PMC4079163 DOI: 10.3892/ijo.2014.2426] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 04/11/2014] [Indexed: 11/06/2022] Open
Abstract
Fucoidan is known to have various pharmacological effects, including antitumor activity. Although it has potential as a therapeutic agent for cancer cells, the anti-senescence effects and detailed mechanism of action remain poorly understood in normal hepatic cells. We investigated the anticancer functions of fucoidan using HepG2 cells as well as the mechanisms mediating the anti-senescent actions in Chang liver cells. Fucoidan effectively inhibited HepG2 cell viability and induced apoptosis. Also, fucoidan-induced G₁ phase arrest was caused by the activity of the p16(INK4a)-Rb and p14(Arf)-p53 pathways. Furthermore, upregulation of p16(INK4a) was critical to the antitumor activity of HepG2 cells treated with fucoidan and was correlated with inhibition of Cdk4 and pRb and upregulation of p21 expression. Our results suggest that fucoidan upregulates INK4a locus genes to induce apoptosis through p38 MAPK in HepG2 cells. Moreover, it prevents cellular senescence of Chang-L cells, by decreasing p14(Arf) expression as cells enter quiescence, with the reduction of p16(INK4a). Fucoidan treatment also downregulated the expression of α₂M. In conclusion, fucoidan can be considered a potential therapeutic agent against liver cancer that does not cause senescence in normal hepatic cells. Thus, it may be possible to use fucoidan therapeutically in both tumor suppression and aging.
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Affiliation(s)
- Eun-Young Min
- Institute of Fisheries Sciences, Pukyong National University, Ilgwang-ro, Ilgwang-myeon, Gijang-gun, Busan 619-911, Republic of Korea
| | - In-Hye Kim
- Institute of Fisheries Sciences, Pukyong National University, Ilgwang-ro, Ilgwang-myeon, Gijang-gun, Busan 619-911, Republic of Korea
| | - Jungim Lee
- Institute of Fisheries Sciences, Pukyong National University, Ilgwang-ro, Ilgwang-myeon, Gijang-gun, Busan 619-911, Republic of Korea
| | - Eun-Young Kim
- Institute of Fisheries Sciences, Pukyong National University, Ilgwang-ro, Ilgwang-myeon, Gijang-gun, Busan 619-911, Republic of Korea
| | - Youn-Hee Choi
- Institute of Fisheries Sciences, Pukyong National University, Ilgwang-ro, Ilgwang-myeon, Gijang-gun, Busan 619-911, Republic of Korea
| | - Taek-Jeong Nam
- Institute of Fisheries Sciences, Pukyong National University, Ilgwang-ro, Ilgwang-myeon, Gijang-gun, Busan 619-911, Republic of Korea
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19
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Piunti A, Rossi A, Cerutti A, Albert M, Jammula S, Scelfo A, Cedrone L, Fragola G, Olsson L, Koseki H, Testa G, Casola S, Helin K, d'Adda di Fagagna F, Pasini D. Polycomb proteins control proliferation and transformation independently of cell cycle checkpoints by regulating DNA replication. Nat Commun 2014; 5:3649. [PMID: 24728135 PMCID: PMC3996544 DOI: 10.1038/ncomms4649] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 03/13/2014] [Indexed: 12/21/2022] Open
Abstract
The ability of PRC1 and PRC2 to promote proliferation is a main feature that links polycomb (PcG) activity to cancer. PcGs silence the expression of the tumour suppressor locus Ink4a/Arf, whose products positively regulate pRb and p53 functions. Enhanced PcG activity is a frequent feature of human tumours, and PcG inhibition has been proposed as a strategy for cancer treatment. However, the recurrent inactivation of pRb/p53 responses in human cancers raises a question regarding the ability of PcG proteins to affect cellular proliferation independently from this checkpoint. Here we demonstrate that PRCs regulate cellular proliferation and transformation independently of the Ink4a/Arf-pRb-p53 pathway. We provide evidence that PRCs localize at replication forks, and that loss of their function directly affects the progression and symmetry of DNA replication forks. Thus, we have identified a novel activity by which PcGs can regulate cell proliferation independently of major cell cycle restriction checkpoints. Polycomb (PcG) proteins are known to promote cell proliferation by silencing expression of the tumour suppressor Ink4A-Arf. Piunti et al. show that PcG proteins also regulate tumour progression independently of this role, revealing a requirement for PRC1 and PRC2 in replication fork progression.
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Affiliation(s)
- Andrea Piunti
- European Institute of Oncology, Department of Experimental Oncology, Milan 20139, Italy
| | - Alessandra Rossi
- European Institute of Oncology, Department of Experimental Oncology, Milan 20139, Italy
| | - Aurora Cerutti
- IFOM Foundation-FIRC Institute of Molecular Oncology Foundation, Milan 20139, Italy
| | - Mareike Albert
- 1] Biotech Research and Innovation, University of Copenhagen, Copenhagen DK-2200, Denmark [2] Centre for Epigenetics, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Sriganesh Jammula
- European Institute of Oncology, Department of Experimental Oncology, Milan 20139, Italy
| | - Andrea Scelfo
- European Institute of Oncology, Department of Experimental Oncology, Milan 20139, Italy
| | - Laura Cedrone
- 1] European Institute of Oncology, Department of Experimental Oncology, Milan 20139, Italy [2] Center for Genomic Science of IIT@SEMM, Istituto Italiano di Tecnologia (IIT), Milan 20139, Italy
| | - Giulia Fragola
- 1] European Institute of Oncology, Department of Experimental Oncology, Milan 20139, Italy [2] IFOM Foundation-FIRC Institute of Molecular Oncology Foundation, Milan 20139, Italy
| | - Linda Olsson
- 1] Biotech Research and Innovation, University of Copenhagen, Copenhagen DK-2200, Denmark [2] Centre for Epigenetics, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Haruhiko Koseki
- Developmental Genetics Group, RIKEN Research Center for Allergy & Immunology (RCAI), 1-7-22 Suehiuro-cho, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - Giuseppe Testa
- European Institute of Oncology, Department of Experimental Oncology, Milan 20139, Italy
| | - Stefano Casola
- IFOM Foundation-FIRC Institute of Molecular Oncology Foundation, Milan 20139, Italy
| | - Kristian Helin
- 1] Biotech Research and Innovation, University of Copenhagen, Copenhagen DK-2200, Denmark [2] Centre for Epigenetics, University of Copenhagen, Copenhagen DK-2200, Denmark [3] The Danish Stem Cell Centre, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Fabrizio d'Adda di Fagagna
- 1] IFOM Foundation-FIRC Institute of Molecular Oncology Foundation, Milan 20139, Italy [2] Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche, Pavia 27100, Italy
| | - Diego Pasini
- European Institute of Oncology, Department of Experimental Oncology, Milan 20139, Italy
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20
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Manuel Iglesias J, Beloqui I, Garcia-Garcia F, Leis O, Vazquez-Martin A, Eguiara A, Cufi S, Pavon A, Menendez JA, Dopazo J, Martin AG. Mammosphere formation in breast carcinoma cell lines depends upon expression of E-cadherin. PLoS One 2013; 8:e77281. [PMID: 24124614 PMCID: PMC3790762 DOI: 10.1371/journal.pone.0077281] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 08/30/2013] [Indexed: 01/06/2023] Open
Abstract
Tumors are heterogeneous at the cellular level where the ability to maintain tumor growth resides in discrete cell populations. Floating sphere-forming assays are broadly used to test stem cell activity in tissues, tumors and cell lines. Spheroids are originated from a small population of cells with stem cell features able to grow in suspension culture and behaving as tumorigenic in mice. We tested the ability of eleven common breast cancer cell lines representing the major breast cancer subtypes to grow as mammospheres, measuring the ability to maintain cell viability upon serial non-adherent passage. Only MCF7, T47D, BT474, MDA-MB-436 and JIMT1 were successfully propagated as long-term mammosphere cultures, measured as the increase in the number of viable cells upon serial non-adherent passages. Other cell lines tested (SKBR3, MDA-MB-231, MDA-MB-468 and MDA-MB-435) formed cell clumps that can be disaggregated mechanically, but cell viability drops dramatically on their second passage. HCC1937 and HCC1569 cells formed typical mammospheres, although they could not be propagated as long-term mammosphere cultures. All the sphere forming lines but MDA-MB-436 express E-cadherin on their surface. Knock down of E-cadherin expression in MCF-7 cells abrogated its ability to grow as mammospheres, while re-expression of E-cadherin in SKBR3 cells allow them to form mammospheres. Therefore, the mammosphere assay is suitable to reveal stem like features in breast cancer cell lines that express E-cadherin.
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Affiliation(s)
- Juan Manuel Iglesias
- Regulation of Cell Growth Laboratory, Fundacion Inbiomed, San Sebastián, Gipuzkoa, Spain
| | - Izaskun Beloqui
- Regulation of Cell Growth Laboratory, Fundacion Inbiomed, San Sebastián, Gipuzkoa, Spain
| | - Francisco Garcia-Garcia
- Computational Genomics Institute, Centro de Investigación Principe Felipe (CIPF), Valencia, Spain
- Functional Genomics Node, INB, CIPF, Valencia, Spain
| | - Olatz Leis
- Regulation of Cell Growth Laboratory, Fundacion Inbiomed, San Sebastián, Gipuzkoa, Spain
| | - Alejandro Vazquez-Martin
- Translational Research Laboratory, Catalan Institute of Oncology (ICO), Girona, Spain
- Girona Biomedical Research Institute (IDIBGi), Girona, Spain
| | - Arrate Eguiara
- Regulation of Cell Growth Laboratory, Fundacion Inbiomed, San Sebastián, Gipuzkoa, Spain
| | - Silvia Cufi
- Translational Research Laboratory, Catalan Institute of Oncology (ICO), Girona, Spain
- Girona Biomedical Research Institute (IDIBGi), Girona, Spain
| | - Andres Pavon
- Regulation of Cell Growth Laboratory, Fundacion Inbiomed, San Sebastián, Gipuzkoa, Spain
| | - Javier A. Menendez
- Translational Research Laboratory, Catalan Institute of Oncology (ICO), Girona, Spain
- Girona Biomedical Research Institute (IDIBGi), Girona, Spain
| | - Joaquin Dopazo
- Computational Genomics Institute, Centro de Investigación Principe Felipe (CIPF), Valencia, Spain
- Functional Genomics Node, INB, CIPF, Valencia, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Angel G. Martin
- Regulation of Cell Growth Laboratory, Fundacion Inbiomed, San Sebastián, Gipuzkoa, Spain
- * E-mail:
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21
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Hata K, Mizuguchi J. Arginine methylation regulates antibody responses through modulating cell division and isotype switching in B cells. Microbiol Immunol 2013; 57:185-92. [DOI: 10.1111/1348-0421.12019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 12/02/2012] [Accepted: 12/12/2012] [Indexed: 11/27/2022]
Affiliation(s)
- Kikumi Hata
- Department of Immunology; Tokyo Medical University; 6-1-1 Shinjuku, Shinjuku-ku; Tokyo; 160-8402; Japan
| | - Junichiro Mizuguchi
- Department of Immunology; Tokyo Medical University; 6-1-1 Shinjuku, Shinjuku-ku; Tokyo; 160-8402; Japan
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22
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Schmid JO, Dong M, Haubeiss S, Friedel G, Bode S, Grabner A, Ott G, Mürdter TE, Oren M, Aulitzky WE, van der Kuip H. Cancer Cells Cue the p53 Response of Cancer-Associated Fibroblasts to Cisplatin. Cancer Res 2012; 72:5824-32. [DOI: 10.1158/0008-5472.can-12-1201] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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23
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Moore LM, Holmes KM, Fuller GN, Zhang W. Oncogene interactions are required for glioma development and progression as revealed by a tissue specific transgenic mouse model. CHINESE JOURNAL OF CANCER 2012; 30:163-72. [PMID: 21352693 PMCID: PMC4013312 DOI: 10.5732/cjc.010.10572] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The aggressive and invasive nature of brain tumors has hampered progress in the design and implementation of efficacious therapies. The recent success of targeted therapies in other tumor types makes this an attractive area for research yet complicating matters is the ability of brain tumors to circumvent the targeted pathways to develop drug resistance. Effective therapies will likely need to target more than one signaling pathway or target multiple nodes within a given pathway. Key to identifying these targets is the elucidation of the driver and passenger molecules within these pathways. Animal models provide a useful tool with many advantages in the study of these pathways. These models provide a means to dissect the critical components of tumorigenesis, as well as serve as agents for preclinical testing. This review focuses on the use of the RCAS/tv-a mouse model of brain tumors and describes their unique ability to provide insight into the role of Oncogene cooperation in tumor development and progression.
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Affiliation(s)
- Lynette M Moore
- Department of Pathology, the University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
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24
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Hepatocyte odd protein shuttling (HOPS) is a bridging protein in the nucleophosmin-p19 Arf network. Oncogene 2012; 32:3350-8. [PMID: 22890319 DOI: 10.1038/onc.2012.353] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 06/26/2012] [Accepted: 06/30/2012] [Indexed: 01/03/2023]
Abstract
Nucleophosmin (NPM), a ubiquitously and abundantly expressed protein, occurs in the nucleolus, shuttling between the nucleoplasm and cytoplasm. The NPM gene is mutated in almost 30% of human acute myeloid leukemia cells. NPM interacts with p53 and p19(Arf), directs localization of p19(Arf) in the nucleolus and protects the latter from degradation. Hepatocyte odd protein shuttling (HOPS) is also a ubiquitously expressed protein that moves between the nucleus and cytoplasm. Within the nucleus of resting cells, HOPS overexpression causes cell cycle arrest in G0/G1. HOPS knockdown causes centrosome hyperamplification leading to multinucleated cells and the formation of micronuclei. We demonstrate a direct interaction of HOPS with NPM and p19(Arf), resulting in a functionally active trimeric complex. NPM appeared to regulate HOPS half-life, which, in turn, stabilized p19(Arf) and controlled its localization in the nucleolus. These findings suggest that HOPS acts as a functional bridge in the interaction between NPM and p19(Arf), providing new mechanistic insight into how NPM and p19(Arf) will oppose tumor cell proliferation.
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25
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Nucleolar protein GLTSCR2 stabilizes p53 in response to ribosomal stresses. Cell Death Differ 2012; 19:1613-22. [PMID: 22522597 DOI: 10.1038/cdd.2012.40] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
p53 is a key regulator of cell growth and death by controlling cell cycle progression and apoptosis under conditions of stress such as DNA damage or oncogenic stimulation. As these processes are critical for cell function and inhibition of tumor development, p53 regulatory pathways are strictly monitored in cells. Recently, it was recognized that nucleolar proteins, including nucleophosmin/B23, ribosomal protein L11, and alternate reading frame (ARF), form the nucleolus-ARF-murine double minute 2 (MDM2) axis in p53 regulatory pathways, which increases p53 stability by suppressing the activity of MDM2. In this work, we show that nucleolar protein glioma tumor-suppressor candidate region gene 2 (GLTSCR2) translocates to the nucleoplasm under ribosomal stress, where it interacts with and stabilizes p53 and inhibits cell cycle progression without the involvement of the major upstream p53 regulator, ARF. Furthermore, ectopic expression of GLTSCR2 significantly suppressed growth of cancer cells in a xenograft animal model via p53-dependent pathway. Our data identify GLTSCR2 as a new member of the nucleolus-nucleoplasmic axis for p53 regulation. ARF-independent direct regulation of p53 by GLTSCR2 may be a key mechanism and therapeutic target for cell death or growth inhibition when nucleolus-ARF-p53 pathways are inactivated by genetic or epigenetic modifications of ARF, which are the second most common types of genetic change observed in human cancers.
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26
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Zerrouqi A, Pyrzynska B, Febbraio M, Brat DJ, Van Meir EG. P14ARF inhibits human glioblastoma-induced angiogenesis by upregulating the expression of TIMP3. J Clin Invest 2012; 122:1283-95. [PMID: 22378045 DOI: 10.1172/jci38596] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 01/11/2012] [Indexed: 11/17/2022] Open
Abstract
Malignant gliomas are the most common and the most lethal primary brain tumors in adults. Among malignant gliomas, 60%-80% show loss of P14ARF tumor suppressor activity due to somatic alterations of the INK4A/ARF genetic locus. The tumor suppressor activity of P14ARF is in part a result of its ability to prevent the degradation of P53 by binding to and sequestering HDM2. However, the subsequent finding of P14ARF loss in conjunction with TP53 gene loss in some tumors suggests the protein may have other P53-independent tumor suppressor functions. Here, we report what we believe to be a novel tumor suppressor function for P14ARF as an inhibitor of tumor-induced angiogenesis. We found that P14ARF mediates antiangiogenic effects by upregulating expression of tissue inhibitor of metalloproteinase-3 (TIMP3) in a P53-independent fashion. Mechanistically, this regulation occurred at the gene transcription level and was controlled by HDM2-SP1 interplay, where P14ARF relieved a dominant negative interaction of HDM2 with SP1. P14ARF-induced expression of TIMP3 inhibited endothelial cell migration and vessel formation in response to angiogenic stimuli produced by cancer cells. The discovery of this angiogenesis regulatory pathway may provide new insights into P53-independent P14ARF tumor-suppressive mechanisms that have implications for the development of novel therapies directed at tumors and other diseases characterized by vascular pathology.
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Affiliation(s)
- Abdessamad Zerrouqi
- Laboratory of Molecular Neuro-Oncology, Department of Neurosurgery, School of Medicine, Emory University, Atlanta, Georgia 30322, USA
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Padilla-Nash HM, Hathcock K, McNeil NE, Mack D, Hoeppner D, Ravin R, Knutsen T, Yonescu R, Wangsa D, Dorritie K, Barenboim L, Hu Y, Ried T. Spontaneous transformation of murine epithelial cells requires the early acquisition of specific chromosomal aneuploidies and genomic imbalances. Genes Chromosomes Cancer 2011; 51:353-74. [PMID: 22161874 DOI: 10.1002/gcc.21921] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 11/09/2011] [Indexed: 01/10/2023] Open
Abstract
Human carcinomas are defined by recurrent chromosomal aneuploidies, which result in a tissue-specific distribution of genomic imbalances. In order to develop models for these genome mutations and to determine their role in tumorigenesis, we generated 45 spontaneously transformed murine cell lines from normal epithelial cells derived from bladder, cervix, colon, kidney, lung, and mammary gland. Phenotypic changes, chromosomal aberrations, centrosome number, and telomerase activity were assayed in control uncultured cells and in three subsequent stages of transformation. Supernumerary centrosomes, binucleate cells, and tetraploidy were observed as early as 48 hr after explantation. In addition, telomerase activity increased throughout progression. Live-cell imaging revealed that failure of cytokinesis, not cell fusion, promoted genome duplication. Spectral karyotyping demonstrated that aneuploidy preceded immortalization, consisting predominantly of whole chromosome losses (4, 9, 12, 13, 16, and Y) and gains (1, 10, 15, and 19). After transformation, focal amplifications of the oncogenes Myc and Mdm2 were frequently detected. Fifty percent of the transformed lines resulted in tumors on injection into immunocompromised mice. The phenotypic and genomic alterations observed in spontaneously transformed murine epithelial cells recapitulated the aberration pattern observed during human carcinogenesis. The dominant aberration of these cell lines was the presence of specific chromosomal aneuploidies. We propose that our newly derived cancer models will be useful tools to dissect the sequential steps of genome mutations during malignant transformation, and also to identify cancer-specific genes, signaling pathways, and the role of chromosomal instability in this process.
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Mori N. Two loci controlling susceptibility to radiation-induced lymphomagenesis on mouse chromosome 4: cdkn2a, a candidate for one locus, and a novel locus distinct from cdkn2a. Radiat Res 2010; 173:158-64. [PMID: 20095847 DOI: 10.1667/rr1855.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BALB/c mice are sensitive to radiation-induced lymphomagenesis, while STS mice are resistant. Using 219 [(BALB/c x STS)F(1) x BALB/c] (N2C) and 197 [(BALB/c x STS)F(1) x STS] (N2S) animals, we performed a genome-wide search for loci controlling susceptibility to lymphomagenesis induced by radiation. Association of markers with the survival of animals was analyzed by the log rank test. For N2C mice, a significant correlation was detected, with four markers on the proximal to mid portion of chromosome 4: D4Mit302 and D4Mit255, P = 0.0075; D4Mit17, P = 0.034; and D4Mit86, P = 0.048. On the other hand, no significant linkage was detected in N2S mice. We analyzed BALB/c mice congenic for the STS allele in different regions of chromosome 4 and identified a locus with a conspicuous effect on survival located within a 7-Mb region between D4Mit302 and D4Mit144, where BALB/c mice harbor hypomorphic variant alleles of the tumor suppressor gene Cdkn2a, which encodes the cyclin-dependent kinase inhibitor protein p16INK4a. Using pooled F(2) intercrosses between the BALB/c and congenic lines carrying the STS allele near D4Mit17, but not in the range from D4Mit302 to D4Mit144, we assigned the second locus to an 11.4-Mb region in the vicinity of D4Mit17. Although Cdkn2a is a likely candidate for the locus controlling susceptibility to lymphomagenesis on chromosome 4, a novel tumor susceptibility gene different from Cdkn2a exists near the primary locus.
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Affiliation(s)
- Nobuko Mori
- Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai-shi, Osaka 599-8570, Japan.
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ARF-induced downregulation of Mip130/LIN-9 protein levels mediates a positive feedback that leads to increased expression of p16Ink4a and p19Arf. Oncogene 2010; 29:1976-86. [PMID: 20101237 DOI: 10.1038/onc.2009.485] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The ARF-MDM2-p53 pathway constitutes one of the most important mechanisms of surveillance against oncogenic transformation, and its inactivation occurs in a large proportion of cancers. Here, we show that ARF regulates Mip130/LIN-9 by inducing its translocation to the nucleolus and decreasing the expression of the Mip130/LIN-9 protein through a post-transcriptional mechanism. The knockdown of Mip130/LIN-9 in p53(-/-) and Arf(-/-) mouse embryonic fibroblasts (MEFs) mimics some effects of ARF, such as the downregulation of B-Myb, impaired induction of G2/M genes, and a decrease in cell proliferation. Importantly, although the knockdown of Mip130/LIN-9 reduced the proliferation of p53 or Arf-null MEFs, only p53(-/-) MEFs showed a senescence-like state and an increase in the expression of Arf and p16. Interestingly, the increase in p16 and ARF is indirect because the Mip130/LIN-9 knockdown decreased the transcription of negative regulators of the Ink4a/Arf locus, such as BUBR1 and CDC6. Chromatin immunoprecipitation assays also reveal that Mip130/LIN-9 occupies the promoters of the BubR1 and cdc6 genes, suggesting that Mip130/LIN-9 is necessary for the expression of these genes. Altogether, these results indicate that there is a feedback mechanism between ARF and Mip130/LIN-9 in which either the increase of ARF or the decrease in Mip130/LIN-9 causes a further increase in the expression of Arf and p16.
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Abstract
Loss of p53 function occurs during the development of most, if not all, tumour types. This paves the way for genomic instability, tumour-associated changes in metabolism, insensitivity to apoptotic signals, invasiveness and motility. However, the nature of the causal link between early tumorigenic events and the induction of the p53-mediated checkpoints that constitute a barrier to tumour progression remains uncertain. This Review considers the role of the DNA damage response, which is activated during the early stages of tumour development, in mobilizing the tumour suppression function of p53. The relationship between these events and oncogene-induced p53 activation through the ARF pathway is also discussed.
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Affiliation(s)
- David W Meek
- Biomedical Research Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK.
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IGFBP2 is a candidate biomarker for Ink4a-Arf status and a therapeutic target for high-grade gliomas. Proc Natl Acad Sci U S A 2009; 106:16675-9. [PMID: 19805356 DOI: 10.1073/pnas.0900807106] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The levels of insulin-like growth factor-binding protein 2 (IGFBP2) are elevated during progression of many human cancers. By using a glial-specific transgenic mouse system (RCAS/Ntv-a), we reported previously that IGFBP2 is an oncogenic factor for glioma progression in combination with platelet-derived growth factor-beta (PDGFB). Because the INK4a-ARF locus is often deleted in high-grade gliomas (anaplastic oligodendroglioma and glioblastoma), we investigated the effect of the Ink4a-Arf-null background on IGFBP2-mediated progression of PDGFB-initiated oligodendroglioma. We demonstrate here that homozygous deletion of Ink4a-Arf bypasses the requirement of exogenously introduced IGFBP2 for glioma progression. Instead, absence of Ink4a-Arf resulted in elevated endogenous tumor cell IGFBP2. An inverse relationship between p16(INK4a) and IGFBP2 expression was also observed in human glioma tissue samples and in 90 different cancer cell lines by using Western blotting and reverse-phase protein lysate arrays. When endogenous IGFBP2 expression was attenuated by an RCAS vector expressing antisense IGFBP2 in our mouse model, a decreased incidence of anaplastic oligodendroglioma as well as prolonged survival was observed. Thus, p16(INK4a) is a negative regulator of the IGFBP2 oncogene. Loss of Ink4a-Arf results in increased IGFBP2, which contributes to glioma progression, thereby implicating IGFBP2 as a marker and potential therapeutic target for Ink4a-Arf-deleted gliomas.
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Besplug J, Burke P, Ponton A, Filkowski J, Titov V, Kovalchuk I, Kovalchuk O. Sex and tissue-specific differences in low-dose radiation-induced oncogenic signaling. Int J Radiat Biol 2009; 81:157-68. [PMID: 16019925 DOI: 10.1080/09553000500103512] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE The possible adverse health effects of low-dose radiation (LDR) exposure constitute a growing concern. Clinically and environmentally relevant exposures occur predominantly under chronic conditions, notwithstanding that most studies of LDR effects have been performed using a single acute exposure. Sex- and tissue-specificity of the LDR-induced changes have not been considered before. We investigated LDR-related expression patterns in muscle, liver and spleen of male and female mice subjected to acute and chronic LDR exposure. Genes involved in oncogenic signaling were of specific interest, as radiation is a well-known carcinogen. MATERIALS AND METHODS We analyzed the expression pattern of genes coding for growth factors and growth-factor receptors, cytoplasmic serine/threonine protein kinases, G-proteins and nuclear DNA-binding proteins, and other important components of oncogenic signaling. RESULTS We found sex- and tissue-specific changes in the expression of Ras superfamily members (Nras, Rab2, Rab34, Vav2), protein kinase C (PKC) isoforms (PKCbeta, PKCmu), AP-1 factor components (Jun, JunB and FosB), Wnt signaling pathway members as well as in a variety of other cellular proto-oncogenes and oncogenes. Importantly, Western blot analysis of JunB, PKCmu and Rab2 proteins supported the transcriptomic data. CONCLUSIONS Substantially different protein levels were observed in all three tissues (muscle, spleen and liver) of acutely and chronically irradiated female and male animals. Based on the obtained data and available literature, we discuss several possible mechanisms that may contribute to radiation-induced carcinogenesis in various tissues of males and females. From our results we could identify the genes that may serve as sex- and tissue-specific biomarkers of the LDR exposure.
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Affiliation(s)
- Jill Besplug
- Department of Biological Sciences, University of Lethbridge, Alberta, Canada
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Aging of the inceptive cellular population: the relationship between stem cells and aging. Aging (Albany NY) 2009; 1:372-81. [PMID: 20157525 PMCID: PMC2806020 DOI: 10.18632/aging.100036] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Accepted: 04/01/2009] [Indexed: 12/12/2022]
Abstract
The average life expectancy worldwide has about doubled and the global population has increased six fold over the past century. With improving health care in the developed world there is a proportional augmentation in the treatment necessary for elderly patients occasioning the call for increased research in the area of aging and age-related diseases. The manifestation of this research has been focalized on the causative cellular processes and molecular mechanisms involved. Here we will discuss the efforts of this research in the area of stem cells, delving into the regulatory mechanisms and how their de-regulation could be attributed to aging and age-related diseases.
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Morrison JP, Satoh H, Foley J, Horton JL, Dunnick JK, Kissling GE, Malarkey DE. N-ethyl-N-nitrosourea (ENU)-induced meningiomatosis and meningioma in p16(INK4a)/p19(ARF) tumor suppressor gene-deficient mice. Toxicol Pathol 2008; 35:780-7. [PMID: 17943659 DOI: 10.1080/01926230701584130] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The cyclin-dependent kinase (CDK) inhibitor p16(INK4a) and the MDM2 ubiquitin ligase inhibitor p19(ARF) are critical to the regulation of cell cycle progression. Their loss by deletion, mutation or epigenetic silencing is a common molecular alteration in many human cancers. To investigate the role of p16(INK4a)/p19(ARF) deficiency in CNS tumor pathogenesis, pregnant mice bearing p16(-/-)/p19(-/-), p16(+/-)/p19(+/-), and p16(+/+)/p19(+/+) embryos were exposed transplacentally on gestation day 14 to a single dose of the potent carcinogen, ethylnitrosourea (ENU). p16(+/-)/p19(+/-) male mice treated with ENU developed meningial proliferative lesions with a high incidence (5/10). The incidence was lower in other ENU-treated animals of both sexes and none occurred in saline-treated control animals. The lesions ranged from widespread meningeal proliferation and plaque-like thickening by neoplastic spindle cells consistent with meningiomatosis to a larger discrete mass consistent with a meningioma. Ultrastructural analysis revealed the presence of intercellular junctions between cells, supporting a meningothelial histogenesis. Spontaneous meningiomas occur rarely in wild-type mice but are a common neoplasm afflicting humans, accounting for between 13 and 26% of primary intracranial neoplasms. This ENU inducible meningeal lesion in p16(+/-)/p19(+/-) mice may provide additional insight into the pathogenesis of meningeal neoplasia and aid the development of therapeutics.
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Affiliation(s)
- James P Morrison
- Charles River Laboratories, Pathology Associates, Durham, North Carolina 27703, USA
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Gambichler T, Bischoff S, Bechara FG, Altmeyer P, Kreuter A. Expression of proliferation markers and cell cycle regulators in T cell lymphoproliferative skin disorders. J Dermatol Sci 2007; 49:125-32. [PMID: 17826963 DOI: 10.1016/j.jdermsci.2007.07.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Revised: 06/03/2007] [Accepted: 07/27/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND Abnormal cell proliferation, which results from deregulation of the cell cycle, is fundamental in tumorigenesis. OBJECTIVES To investigate the expression of proliferation markers and cell cycle regulators in a range of T cell lymphoproliferative skin diseases. METHODS We studied skin specimens of 51 patients with parapsoriasis (PP), mycosis fungiodes (MF), or lymphomatoid papulosis (LyP). Immunohistochemistry was performed for Ki-67, proliferating cell nuclear antigen (PCNA), minichromosome maintenance protein 7 (MCM7), and p21. RESULTS MF with stage IIB-IV and LyP showed a significantly greater number of Ki-67-positive cells than PP (P=0.02 and 0.001) and MF I-IIA (P=0.019 and 0.003), respectively. MCM7 staining revealed significantly higher labeling indices for MF IIB-IV and LyP when compared to PP (P=0.002 and 0.04) and MF I-IIA (P=0.0005 and 0.01), respectively. Compared to PP and MF I-IIA, MF IIB-IV was associated with significantly higher labeling indices for PCNA (P=0.006 and 0.0004). p21 staining was significantly increased in MF IIB-IV and LyP when compared to PP (P=0.006 and 0.003) and MF I-IIA (P=0.003). However, p21 staining was all in all very weak. CONCLUSIONS Ki-67 and PCNA seem to be useful immunohistological parameters for the correlation with the clinical stage of MF. In the differentiation and prognostication of T cell lymphoproliferative skin disorders, MCM7 may serve as a novel biomarker which is, in contrast to Ki-67 and PCNA, stable throughout the cell cycle.
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Affiliation(s)
- Thilo Gambichler
- Department of Dermatology, Ruhr-University Bochum, Gudrunstrasse 56, 44791, Bochum, Germany.
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Chang DLF, Qiu W, Ying H, Zhang Y, Chen CY, Xiao ZXJ. ARF promotes accumulation of retinoblastoma protein through inhibition of MDM2. Oncogene 2007; 26:4627-34. [PMID: 17297463 DOI: 10.1038/sj.onc.1210254] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The INK4a/ARF locus, encoding two tumor suppressor proteins, p16(INK4a) and p14(ARF) (ARF), plays key roles in many cellular processes including cell proliferation, apoptosis, cellular senescence and differentiation. Inactivation of INK4a/ARF is one of the most frequent events during human cancer development. Although p16(INK4a) is a critical component in retinoblastoma protein (Rb)-mediated growth regulatory pathway, p14(ARF) plays a pivotal role in the activation of p53 upon oncogenic stress signals. A body of evidence indicates that ARF also possesses growth suppression functions independent of p53, the mechanism of which is not well understood. We have recently shown that MDM2 interacts with Rb and promotes proteasome-dependent Rb degradation. In this study, we show that ARF disrupts MDM2-Rb interaction resulting in Rb accumulation. Wild-type ARF, but not ARF mutant defective in MDM2 interaction, stabilizes Rb and inhibits colony foci formation independent of p53. In addition, ablation of Rb impairs ARF function in growth suppression. Thus, this study demonstrates that ARF plays a direct role in regulation of Rb and suggests that inactivation of ARF may lead to defects in both p53 and Rb pathways in human cancer development.
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Affiliation(s)
- D L F Chang
- Graduate Program in Molecular Medicine, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
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Tian KH, Shen Y, Luo YR, Wang MZ, Liu HX, Zhao HR, Zhang L. Hypermethylation of p14ARF promoter region and expresion of p14ARF gene product in non-small cell lung cancer. Chin J Cancer Res 2006. [DOI: 10.1007/s11670-006-0276-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Aizu W, Belinsky GS, Flynn C, Noonan EJ, Boes CC, Godman CA, Doshi B, Nambiar PR, Rosenberg DW, Giardina C. Circumvention and reactivation of the p53 oncogene checkpoint in mouse colon tumors. Biochem Pharmacol 2006; 72:981-91. [PMID: 16949053 DOI: 10.1016/j.bcp.2006.07.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 06/29/2006] [Accepted: 07/17/2006] [Indexed: 01/25/2023]
Abstract
The p53 tumor suppressor protein is sequence-normal in azoxymethane (AOM)-induced mouse colon tumors, making them a good model for human colon cancers that retain a wild type p53 gene. Cellular localization and co-immunoprecipitation experiments using a cell line derived from an AOM-induced colon tumor (AJ02-NM(0) cells) pointed to constitutively expressed Mdm2 as being an important negative regulator of p53 in these cells. Although the Mdm2 inhibitory protein p19/ARF was expressed in AJ02-NM(0) cells, its level of expression was not sufficient for p53 activation. We tested the response of AJ02-NM(0) cells to the recently developed Mdm2 inhibitor, Nutlin-3. Nutlin-3 was found to activate p53 DNA binding in AJ02-NM(0) cells, to a level comparable to doxorubicin and 5-fluorouracil (5-FU). In addition, Nutlin-3 increased expression of the p53 target genes Bax and PERP to a greater extent than doxorubicin or 5-FU, and triggered a G2/M phase arrest in these cells, compared to a G1 arrest triggered by doxorubicin and 5-FU. The differences in the cellular response may be related to differences in the kinetics of p53 activation and/or its post-translational modification status. In an ex vivo experiment, Nutlin-3 was found to activate p53 target gene expression and apoptosis in AOM-induced tumor tissue, but not in normal adjacent mucosa. Our data indicate that Mdm2 inhibitors may be an effective means of selectively targeting colon cancers that retain a sequence-normal p53 gene while sparing normal tissue and that the AOM model is an appropriate model for the preclinical development of these drugs.
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Affiliation(s)
- Wataru Aizu
- Department of Molecular & Cell Biology, 91 North Eagleville Road, University of Connecticut, Storrs, CT 06269-3125, USA
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Yurakh AO, Ramos D, Calabuig-Fariñas S, López-Guerrero JA, Rubio J, Solsona E, Romanenko AM, Vozianov AF, Pellin A, Llombart-Bosch A. Molecular and immunohistochemical analysis of the prognostic value of cell-cycle regulators in urothelial neoplasms of the bladder. Eur Urol 2006; 50:506-15; discussion 515. [PMID: 16624482 DOI: 10.1016/j.eururo.2006.03.027] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Accepted: 03/13/2006] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To evaluate the prognostic and predictive value of molecular and immunohistochemical markers related to cell-cycle control in terms of recurrence, progression, and survival in urothelial neoplasms of the bladder (UNB). PATIENTS AND METHODS Clinical and pathological findings of 84 patients with UNB were assessed. Homozygous deletion (HD) and promoter methylation of p14ARF, p15INK4B, p16INK4A, loss of heterozygosity of the locus 9p21, p53 mutations, and immunohistochemical expression of p53, p16, p14, p21, p27, pRb, Ki67, MDM2, and cyclin D1 proteins were evaluated in relation to overall survival (OS), recurrence-free survival (RFS), and progression-free survival (PFS). RESULTS In the univariate analysis, RFS was shorter in cases with p14ARF (p=0.006), p15INK4B (p=0.003), p16INK4A (p=0.03) HD, low p14 immunoreactivity index (IRI) (p=0.01) and high Ki67 IRI (p=0.04); HD of the 9p21 locus genes and p14 IRI remained as independent prognostic factors for early UNB recurrence (p=0.006) whereas tumour stage (p=0.00001) and cyclin D1 IRI (p=0.049) were related to worse PFS in the multivariate analysis. In the univariate analysis, IRI for Ki67 (p=0.002), cyclin D1 (p=0.06), p53 (p=0.00008), p16 (p=0.02), p27 (p=0.0005) MDM2 (p=0.01) and p53 mutations (p=0.03) were related to poor OS, and only the Ki67 IRI retained their independent value in the multivariate analysis. CONCLUSION 9p21 HD and p14 IRI constitute independent predictive factors for UNB recurrence and cyclin D1 IRI and tumour stage for progression. In addition, Ki67 IRI and tumour stage are independent prognostic factors for overall survival in UNB.
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Affiliation(s)
- Andriy O Yurakh
- Institute of Urology, Academy of Medical Science of Ukraine, Kyiv, Ukraine.
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Zalcenstein A, Weisz L, Stambolsky P, Bar J, Rotter V, Oren M. Repression of the MSP/MST-1 gene contributes to the antiapoptotic gain of function of mutant p53. Oncogene 2006; 25:359-69. [PMID: 16170349 DOI: 10.1038/sj.onc.1209061] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Tumor-associated mutant forms of p53 can exert an antiapoptotic gain of function activity, which confers a selective advantage upon tumor cells harboring such mutations. We report that mutant p53 suppresses the expression of the MSP (MST-1/HGFL) gene, encoding the ligand of the receptor tyrosine kinase RON, implicated in a variety of cellular responses. Mutant p53 associates with the MSP gene promoter and represses its transcriptional activity, leading to a decrease in mRNA levels and a subsequent decrease in the levels of secreted MSP protein. Forced downregulation of MSP expression in H1299 cells, derived from a large-cell lung carcinoma, confers increased resistance against etoposide-induced cell death. These antiapoptotic consequences of MSP downregulation seemingly conflict with the well-documented ability of the RON receptor to promote cell survival and tumor progression when aberrantly hyperactive. Yet, they are consistent with the fact that reduced MSP expression was observed in many types of human cancer, including large-cell lung carcinoma. Thus, repression of MSP gene expression by mutant p53 may contribute to oncogenesis in a cell type-specific manner.
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Affiliation(s)
- A Zalcenstein
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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Chapman EJ, Harnden P, Chambers P, Johnston C, Knowles MA. Comprehensive analysis of CDKN2A status in microdissected urothelial cell carcinoma reveals potential haploinsufficiency, a high frequency of homozygous co-deletion and associations with clinical phenotype. Clin Cancer Res 2005; 11:5740-7. [PMID: 16115911 DOI: 10.1158/1078-0432.ccr-05-0411] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE There are significant differences in reported frequencies, modes of inactivation, and clinical significance of CDKN2A in urothelial cell carcinoma (UCC). We aimed to address these issues by investigating all possible modes of inactivation and clinicopathologic variables in a single tumor panel. EXPERIMENTAL DESIGN Fifty microdissected UCCs were examined. CDKN2A gene dosage (quantitative real-time PCR), allelic status (microsatellite analysis), hypermethylation (methylation-specific PCR), mutation status (denaturing high-performance liquid chromatography and sequencing), protein expression (immunohistochemistry), and clinicopathologic variables (stage, grade, and disease recurrence during follow-up) were assessed. RESULTS Exon 2 was underrepresented in 20 of 46 (43%) and exon 1beta in 21 of 46 (46%) of cases. Underrepresentation of exon 2 was accompanied by loss of heterozygosity (LOH) of 9p in 6 of 18 (30%) and of exon 1beta in 11 of 19 assessable cases (58%). Overall, LOH of 9p was identified in 15/41 (37%). Homozygous deletion of exons 2 and 1beta was detected in 16 of 46 (35%) and 10 of 46 tumors (22%), respectively. Co-deletion was most common, but exon 2-specific homozygous deletion was also detected. In tumors without homozygous deletion, p16 promoter hypermethylation was detected in 1 of 18 (6%). Hypermethylation of the p14ARF promoter or mutations in CDKN2A were not observed. Homozygous deletion of exon 2 or LOH on 9p were associated with invasion. Homozygous deletion of exon 2 or exon 1beta was associated with recurrent disease. CONCLUSIONS These results confirm CDKN2A as a clinically relevant target for inactivation in UCC and show that the true frequency of alteration is only revealed by comprehensive analysis. Our results suggest that CDKN2A may be haploinsufficient in human cancer.
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Affiliation(s)
- Emma J Chapman
- Cancer Research UK Clinical Centre, St. James's University Hospital, Leeds, United Kingdom
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Abstract
Cancer of the bladder shows divergent clinical behaviour following diagnosis and it has been proposed that two major groups of tumours exist that develop via different molecular pathways. Low-grade, non-invasive papillary tumours recur frequently, but patients with these tumours do not often suffer progression of disease to muscle invasion. In contrast, tumours that are invading muscle at diagnosis are aggressive and associated with significant mortality. Molecular studies have identified distinct genetic, epigenetic and expression changes in these groups. However, it is not yet clear whether there is direct progression of low-grade superficial tumours to become invasive (a Jeckell and Hyde scenario) or whether in those patients who apparently progress from one form of the disease to the other, different tumour clones are involved and that the two tumour groups are mutually exclusive ('chalk and cheese'). If the latter is true, then attempts to identify molecular markers to predict progression of low-grade superficial bladder tumours may be fruitless. Similarly, it is not clear whether other subgroups of tumours exist that arise via different molecular pathways. There is now a large amount of molecular information about bladder cancer that facilitates examination of these possibilities. Some recent studies provide evidence for the existence of at least one further group of tumours, high-grade superficial papillary tumours, which may develop via a distinct molecular pathway. Patients with such tumours do show increased risk of disease progression and for these there may exist a real progression continuum from non-invasive to invasive. If this is the case, definition of the molecular signature of this pathway and improved understanding of the biological consequences of the events involved will be pivotal in disease management.
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Affiliation(s)
- Margaret A Knowles
- Cancer Research UK Clinical Centre, St James's University Hospital, Beckett Street, Leeds LS9 7TF, UK.
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Pauklin S, Kristjuhan A, Maimets T, Jaks V. ARF and ATM/ATR cooperate in p53-mediated apoptosis upon oncogenic stress. Biochem Biophys Res Commun 2005; 334:386-94. [PMID: 16004968 DOI: 10.1016/j.bbrc.2005.06.097] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Accepted: 06/16/2005] [Indexed: 11/30/2022]
Abstract
Induction of apoptosis is pivotal for eliminating cells with damaged DNA or deregulated proliferation. We show that tumor suppressor ARF and ATM/ATR kinase pathways cooperate in the induction of apoptosis in response to elevated expression of c-myc, beta-catenin or human papilloma virus E7 oncogenes. Overexpression of oncogenes leads to the formation of phosphorylated H2AX foci, induction of Rad51 protein levels and ATM/ATR-dependent phosphorylation of p53. Inhibition of ATM/ATR kinases abolishes both induction of Rad51 and phosphorylation of p53, and remarkably reduces the level of apoptosis induced by co-expression of oncogenes and ARF. However, the induction of apoptosis is downregulated in p53-/- cells and does not depend on activities of ATM/ATR kinases, indicating that efficient induction of apoptosis by oncogene activation depends on coordinated action of ARF and ATM/ATR pathways in the regulation of p53.
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Affiliation(s)
- Siim Pauklin
- Department of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Street, Tartu 51010, Estonia.
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44
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di Pietro A, Vries EGED, Gietema JA, Spierings DCJ, de Jong S. Testicular germ cell tumours: the paradigm of chemo-sensitive solid tumours. Int J Biochem Cell Biol 2005; 37:2437-56. [PMID: 16099193 DOI: 10.1016/j.biocel.2005.06.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2005] [Revised: 06/02/2005] [Accepted: 01/27/2005] [Indexed: 11/16/2022]
Abstract
Testicular germ cell tumours (TGCTs) are the most frequent solid malignant tumour in men 20-40 years of age and the most frequent cause of death from solid tumours in this age group. Up to 50% of the patients suffer from metastatic disease at diagnosis. The majority of metastatic testicular cancer patients, in contrast to most other metastatic solid tumours, can be cured with highly effective cisplatin-based chemotherapy. From a genetic point of view, almost all TGCTs in contrast to solid tumours are characterised by the presence of wild type p53. High p53 expression levels are associated with elevated Mdm2 levels and a loss of p21(Waf1/Cip1) expression suggesting a changed functionality of p53. Expression levels of other proteins involved in the regulation of cell cycle progression indicate a deregulated G1-S phase checkpoint in TGCTs. After cisplatin-induced DNA damage, the increasing levels of p53 lead to the trans-activation of a number of genes but not of p21(Waf1/Cip1), preferentially directing TGCT cells into apoptosis or programmed cell death, both via the mitochondrial and the death receptor apoptosis pathways. The sensitivity of TGCTs to chemotherapeutic drugs may lay in the susceptibility of germ cells to apoptosis. Taken together, this provides TGCT as a tumour type model to investigate and understand the molecular determinants of chemotherapy sensitivity of solid tumours. This review aims to summarise the current knowledge on the biological basis of cisplatin-induced apoptosis and response to chemotherapy in TGCTs.
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Affiliation(s)
- Alessandra di Pietro
- Department of Medical Oncology, Internal Medicine, University of Groningen and University Medical Center Groningen, 9713 GZ Hanzeplein 1, Groningen, The Netherlands
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Pons M, Cigudosa JC, Rodríguez-Perales S, Bella JL, González C, Gamallo C, Quintanilla M. Chromosomal instability and phenotypic plasticity during the squamous–spindle carcinoma transition: association of a specific T(14;15) with malignant progression. Oncogene 2005; 24:7608-18. [PMID: 16007119 DOI: 10.1038/sj.onc.1208903] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In mouse epidermal carcinogenesis, the latest stage of malignant progression involves the transition from squamous cell carcinoma to a highly aggressive type of tumor with spindle morphology. In this work, we have isolated a minor epithelial cell subpopulation (CarC-R) contained in the highly malignant spindle carcinoma cell line CarC. CarC-R exhibited a drastic reduction in tumorigenicity when compared with CarC, but CarC-R-induced tumors were mainly sarcomatoid, although they subsequently reverted to the epithelial phenotype when tumor explants were recultured in vitro. Several single-cell clones with either stable epithelial or fibroblastic phenotypes were isolated from an explanted CarC-R tumor (CarC-RT). All these cell lines contained the same specific point mutation in H-Ras codon 61, but while CarC spindle cells had lost the normal H-Ras allele, it was retained in CarC-R- and CarC-RT-derived cell lines. Furthermore, CarC cells have inactivated p16INK4a and p19INK4a/ARF transcription, while CarC-R and CarC-RT clones expressed p19 mRNA and protein but not p16. Altogether, these results suggest that CarC-R represents a precursor stage to CarC in malignant progression. Spectral karyotyping analysis revealed that CarC-R was highly aneuploid and contained many chromosomal abnormalities. In contrast, CarC had a diploid or tetraploid modal chromosome number and contained a specific T(14;15) translocation in all of the analysed metaphases. The T(14;15) translocation was present in only a minority (1.9%) of CarC-R cells, but it was widely spread in CarC-RT and its derived cell clones, regardless of their epithelial or fibroblastic phenotype, indicating that T(14;15) segregates with malignancy.
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Affiliation(s)
- Mar Pons
- Instituto de Investigaciones Biomédicas, Alberto Sols, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Arturo Duperier 4, Madrid 28029, Spain
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Tanaka H, Terada Y, Okado T, Inoshita S, Kuwahara M, Sasaki S. Role of the E2F1-p19-p53 pathway in ischemic acute renal failure. Nephron Clin Pract 2005; 101:p27-34. [PMID: 15990448 DOI: 10.1159/000086642] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2003] [Accepted: 03/22/2005] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Cell cycle progression and arrest of renal tubular cells after acute injury is a reactive process of renal regeneration. The p16(INK4a)/p19(ARF) (alternative reading frame) locus encodes two proteins involved in cell cycle regulation. We investigated the transcriptional regulation and tissue distribution of p19(ARF) in ischemic acute renal failure (ARF). METHODS We examined the time course and immunohistochemistry of p19(ARF) in rat kidneys following the induction of ischemic ARF. We also examined the effect of p19(ARF) overexpression on p53 levels and cell cycle progression in MDCK cells. RESULTS The protein expression of p19(ARF) strongly increased 72 h after the ischemia. Immunohistochemical studies showed that the renal tubular cells in the outer medulla expressed p19(ARF) protein 72 h after ischemic injury. The time course of E2F1 induction was observed at 6-24 h, and it was found to precede p19(ARF) expression. In MDCK cells, the overexpression of E2F1 increased promoter activity and the protein level of p19(ARF) and induced apoptosis. Transfection of the p19(ARF) expression vector caused an increase in p53 protein, cell cycle arrest and apoptosis. CONCLUSIONS These data support the hypothesis that the E2F1-p19(ARF)-p53 pathway forms a negative feedback loop to regulate the cell cycle of renal tubular cells in the ischemic ARF.
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Affiliation(s)
- Hiroyuki Tanaka
- Department of Nephrology, Tokyo Medical and Dental University, Tokyo, Japan
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Aveyard JS, Knowles MA. Measurement of relative copy number of CDKN2A/ARF and CDKN2B in bladder cancer by real-time quantitative PCR and multiplex ligation-dependent probe amplification. J Mol Diagn 2005; 6:356-65. [PMID: 15507675 PMCID: PMC1867481 DOI: 10.1016/s1525-1578(10)60532-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Many tumors have large homozygous deletions of the CDKN2A locus (encoding p14(ARF) and p16) and of CDKN2B (p15). Our aim was to determine which gene is the major target in bladder cancer. We used quantitative real-time PCR (RTQ-PCR) to determine copy number of p15, of p14(ARF) exon 1beta, and p16 exon 2 in 22 tumor cell lines and 83 bladder tumors, some of which had been assessed previously by duplex PCR. Titration experiments showed that homozygous deletion could be detected in the presence of up to 30% normal DNA. Results for cell lines were compatible with previous cytogenetic analyses. Ten cell lines and 32 tumors (38.5%) had homozygous deletion of at least one target. Thirteen tumors (15.7%) had deletion of all three targets. Two tumors had deletion of p14(ARF) exon 1beta alone and four of p16 exon 2 alone. RTQ-PCR detected more homozygous deletions than duplex PCR. Finally we used a multiplex ligation-dependent probe amplification kit to provide independent confirmation of results. We conclude that with appropriate controls RTQ-PCR is a sensitive and robust method to detect copy number changes in tumors even in the presence of contaminating normal cell DNA.
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Affiliation(s)
- Joanne S Aveyard
- Cancer Research UK Clinical Centre, St. James's University Hospital, Beckett Street, Leeds, LS9 7TF UK
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48
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Ameyar-Zazoua M, Wisniewska MB, Bakiri L, Wagner EF, Yaniv M, Weitzman JB. AP-1 dimers regulate transcription of the p14/p19ARF tumor suppressor gene. Oncogene 2005; 24:2298-306. [PMID: 15688012 DOI: 10.1038/sj.onc.1208424] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Evidence is accumulating about the role of individual AP-1 components in cell proliferation and transformation. Notably, Ras-mediated transformation is characterized by the upregulation of particular AP-1 members, such as c-Jun and Fra-1. The p14/p19ARF tumor suppressor gene is a key link between oncogenic Ras signaling and the p53 pathway. We explored the involvement of AP-1 dimers in the transcriptional regulation of the p14/p19ARF gene. We demonstrate that both the human and mouse ARF promoters are transcriptional targets of selective AP-1 dimers. The ARF promoter is regulated specifically by AP-1 heterodimers containing Fra-1. Overexpression of c-Jun approximately Fra-1 dimers in primary murine fibroblast cells led to the upregulation of the endogenous ARF protein and growth arrest. Conversely, inhibition of c-Jun or Fra-1 protein levels resulted in decreased ARF expression. In addition, we show that AP-1 dimers cooperate with oncogenic Ras in the transcriptional activation of the p14/p19ARF promoter. Thus, AP-1 heterodimers may contribute to the regulation of ARF expression upon oncogenic signaling.
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Affiliation(s)
- Maya Ameyar-Zazoua
- Unit of Gene Expression and Disease, Department of Developmental Biology, Pasteur Institute, 25, rue du Docteur Roux, 75724 Paris Cedex 15, France
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Abstract
In recent years several new mouse models for lung cancer have been described. These include models for both non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). Tumorigenesis in these conditional mouse tumor models can be initiated in adult mice through Cre-recombinase-induced activation of oncogenic mutations in a subset of the cells. They present a marked improvement over mouse models that depend on carcinogen induction of tumors. These models permit us to study the consecutive steps involved in initiation and progression and allow us to address questions like the cell of origin, and the role of cancer stem cells in the maintenance of these tumors. They now need to be validated as suitable preclinical models for intervention studies in which questions with respect to therapy response and resistance can be addressed.
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Affiliation(s)
- Ralph Meuwissen
- Division of Molecular Genetics and Center of Biomedical Genetics, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
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50
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Martín-Caballero J, Flores JM, García-Palencia P, Collado M, Serrano M. Different cooperating effect of p21 or p27 deficiency in combination with INK4a/ARF deletion in mice. Oncogene 2004; 23:8231-7. [PMID: 15378017 DOI: 10.1038/sj.onc.1207863] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The control exerted by the INK4a/ARF locus on cellular proliferation is crucial to restrict tumor development. In agreement with this, mice with defects in this locus are highly tumor prone. However, the potential contribution of other pathways in modulating tumorigenesis in the absence of INK4a/ARF is largely unexplored. In the present study, we investigated the consequences of the combined loss of either of two cyclin-dependent kinase inhibitors, p21 and p27, in cooperation with deletion of the INK4a/ARF locus. Our results show a clear differential effect in tumorigenesis depending on the CKI that is absent. The absence of p21 produced no overt alteration of the lifespan of the INK4a/ARF-null mice, although it modified their tumor spectrum, causing a significant increase in the incidence of fibrosarcomas and the appearance of a small number of rhabdomyosarcomas. In contrast, deficiency of p27 resulted in a significant increase in lethality due to accelerated tumor development, especially in the case of T-cell lymphomas. Finally, combined deficiency of INK4a/ARF and p27 resulted in a significant increase in the number of metastatic tumors. These results demonstrate genetically the oncogenic cooperation between defects on INK4a/ARF and p27, which are common alterations in human cancer.
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Affiliation(s)
- Juan Martín-Caballero
- Molecular Oncology Program, Spanish National Cancer Center (CNIO), Melchor Fernandez Almagro 3, Madrid E-28029, Spain
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