1
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Motofei IG. Biology of cancer; from cellular and molecular mechanisms to developmental processes and adaptation. Semin Cancer Biol 2022; 86:600-615. [PMID: 34695580 DOI: 10.1016/j.semcancer.2021.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/21/2021] [Accepted: 10/10/2021] [Indexed: 02/07/2023]
Abstract
Cancer research has been largely focused on the cellular and molecular levels of investigation. Recent data show that not only the cell but also the extracellular matrix plays a major role in the progression of malignancy. In this way, the cells and the extracellular matrix create a specific local microenvironment that supports malignant development. At the same time, cancer implies a systemic evolution which is closely related to developmental processes and adaptation. Consequently, there is currently a real gap between the local investigation of cancer at the microenvironmental level, and the pathophysiological approach to cancer as a systemic disease. In fact, the cells and the matrix are not only complementary structures but also interdependent components that act synergistically. Such relationships lead to cell-matrix integration, a supracellular form of biological organization that supports tissue development. The emergence of this supracellular level of organization, as a structure, leads to the emergence of the supracellular control of proliferation, as a supracellular function. In humans, proliferation is generally involved in developmental processes and adaptation. These processes suppose a specific configuration at the systemic level, which generates high-order guidance for local supracellular control of proliferation. In conclusion, the supracellular control of proliferation act as an interface between the downstream level of cell division and differentiation, and upstream level of developmental processes and adaptation. Understanding these processes and their disorders is useful not only to complete the big picture of malignancy as a systemic disease, but also to open new treatment perspectives in the form of etiopathogenic (supracellular or informational) therapies.
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Affiliation(s)
- Ion G Motofei
- Department of Oncology/ Surgery, Carol Davila University, St. Pantelimon Hospital, Dionisie Lupu Street, No. 37, Bucharest, 020021, Romania.
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2
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Sha J, Arbesman J, Harter ML. Premature senescence in human melanocytes after exposure to solar UVR: An exosome and UV-miRNA connection. Pigment Cell Melanoma Res 2020; 33:671-684. [PMID: 32386350 DOI: 10.1111/pcmr.12888] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 04/27/2020] [Accepted: 05/02/2020] [Indexed: 01/10/2023]
Abstract
Ultraviolet radiation (UVR) can play two roles: induce cellular senescence and convert skin melanocytes into melanoma. To assess whether this conversion might rely on melanocytes having to first acquire a senescent phenotype, we studied the effects of physiological doses of UVR (UVA + UVB) on quiescent melanocytes in vitro. Repeated doses of UVR induced these melanocytes into a senescent-like state. Additionally, these cells secrete exosomes with specific miRNAs that differ in quantity from those of the un-irradiated melanocytes. Many of the exosomal miRNAs that were differentially enriched regulated genes comprising a "senescence core signature" and encoding factors of the senescence-messaging secretome (SASP), while a subset of the differentially reduced miRNAs targeted DNA repair genes that have been experimentally shown to be repressed in senescent melanocytes. Thus, the selection of specific miRNAs by exosomes and their release from melanocytes after exposure to UVR have activities in inducing these cells into premature senescence.
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Affiliation(s)
- Jingfeng Sha
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Joshua Arbesman
- Dermatology and Plastic Surgery Institute and Cancer Biology, Cleveland Clinic, Cleveland, OH, USA
| | - Marian L Harter
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
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3
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Zeng H, Judson-Torres RL, Shain AH. The Evolution of Melanoma - Moving beyond Binary Models of Genetic Progression. J Invest Dermatol 2019; 140:291-297. [PMID: 31623932 DOI: 10.1016/j.jid.2019.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/25/2019] [Accepted: 08/04/2019] [Indexed: 12/30/2022]
Abstract
To date, over 1000 melanocytic neoplasms, spanning all stages of tumorigenesis, have been sequenced, offering detailed views into their -omic landscapes. This has coincided with advances in genetic engineering technologies that allow molecular biologists to edit the human genome with extreme precision and new mouse models to simulate disease progression. In this review, we describe how these technologies are being harnessed to provide insights into the evolution of melanoma at an unprecedented resolution, revealing that prior models of melanoma evolution, in which pathways are turned 'on' or 'off' in a binary fashion during the run-up to melanoma, are oversimplified.
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Affiliation(s)
- Hanlin Zeng
- University of Utah, Department of Dermatology, Huntsman Cancer Institute, Salt Lake City, Utah
| | - Robert L Judson-Torres
- University of Utah, Department of Dermatology, Huntsman Cancer Institute, Salt Lake City, Utah
| | - A Hunter Shain
- University of California San Francisco, Department of Dermatology, Helen Diller Family Comprehensive Cancer Center, San Francisco, California.
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4
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Zeng H, Jorapur A, Shain AH, Lang UE, Torres R, Zhang Y, McNeal AS, Botton T, Lin J, Donne M, Bastian IN, Yu R, North JP, Pincus L, Ruben BS, Joseph NM, Yeh I, Bastian BC, Judson RL. Bi-allelic Loss of CDKN2A Initiates Melanoma Invasion via BRN2 Activation. Cancer Cell 2018; 34:56-68.e9. [PMID: 29990501 PMCID: PMC6084788 DOI: 10.1016/j.ccell.2018.05.014] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 02/12/2018] [Accepted: 05/30/2018] [Indexed: 02/03/2023]
Abstract
Loss of the CDKN2A tumor suppressor is associated with melanoma metastasis, but the mechanisms connecting the phenomena are unknown. Using CRISPR-Cas9 to engineer a cellular model of melanoma initiation from primary human melanocytes, we discovered that a lineage-restricted transcription factor, BRN2, is downstream of CDKN2A and directly regulated by E2F1. In a cohort of melanocytic tumors that capture distinct progression stages, we observed that CDKN2A loss coincides with both the onset of invasive behavior and increased BRN2 expression. Loss of the CDKN2A protein product p16INK4A permitted metastatic dissemination of human melanoma lines in mice, a phenotype rescued by inhibition of BRN2. These results demonstrate a mechanism by which CDKN2A suppresses the initiation of melanoma invasion through inhibition of BRN2.
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Affiliation(s)
- Hanlin Zeng
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Aparna Jorapur
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA
| | - A Hunter Shain
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Ursula E Lang
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Rodrigo Torres
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Yuntian Zhang
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Andrew S McNeal
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Thomas Botton
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Jue Lin
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94143, USA
| | - Matthew Donne
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA
| | - Ingmar N Bastian
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Richard Yu
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94115, USA; Faculty of Medicine, University of British Columbia, Vancouver, BC V6T1Z3, Canada
| | - Jeffrey P North
- Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Laura Pincus
- Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Beth S Ruben
- Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94115, USA; Palo Alto Medical Foundation, Palo Alto, CA 94301, USA
| | - Nancy M Joseph
- Department of Pathology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Iwei Yeh
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Boris C Bastian
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA; Department of Pathology, University of California San Francisco, San Francisco, CA 94115, USA
| | - Robert L Judson
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA; Department of Dermatology, University of California San Francisco, San Francisco, CA 94115, USA.
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5
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Abstract
Molecular insights from genome and systems biology are influencing how cancer is diagnosed and treated. We critically evaluate big data challenges in precision medicine. The melanoma research community has identified distinct subtypes involving chronic sun-induced damage and the mitogen-activated protein kinase driver pathway. In addition, despite low mutation burden, non-genomic mitogen-activated protein kinase melanoma drivers are found in membrane receptors, metabolism, or epigenetic signaling with the ability to bypass central mitogen-activated protein kinase molecules and activating a similar program of mitogenic effectors. Mutation hotspots, structural modeling, UV signature, and genomic as well as non-genomic mechanisms of disease initiation and progression are taken into consideration to identify resistance mutations and novel drug targets. A comprehensive precision medicine profile of a malignant melanoma patient illustrates future rational drug targeting strategies. Network analysis emphasizes an important role of epigenetic and metabolic master regulators in oncogenesis. Co-occurrence of driver mutations in signaling, metabolic, and epigenetic factors highlights how cumulative alterations of our genomes and epigenomes progressively lead to uncontrolled cell proliferation. Precision insights have the ability to identify independent molecular pathways suitable for drug targeting. Synergistic treatment combinations of orthogonal modalities including immunotherapy, mitogen-activated protein kinase inhibitors, epigenetic inhibitors, and metabolic inhibitors have the potential to overcome immune evasion, side effects, and drug resistance.
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Affiliation(s)
- Fabian V Filipp
- Systems Biology and Cancer Metabolism, Program for Quantitative Systems Biology, University of California Merced, 2500 North Lake Road, Merced, CA, 95343, USA.
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6
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Brown JS. Cancer Immune Equilibrium and Schizophrenia Have Similar Interferon-γ, Tumor Necrosis Factor-α, and Interleukin Expression: A Tumor Model of Schizophrenia. Schizophr Bull 2016; 42:1407-1417. [PMID: 27169466 PMCID: PMC5049534 DOI: 10.1093/schbul/sbw064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
For at least a century, a debate has continued as to whether cancer risk is reduced in schizophrenia. Genetic studies have also suggested the 2 conditions may share protein transcriptional pathways. The author predicted that if the pathophysiology of schizophrenia confers protection from cancer, then the immunology of schizophrenia should reflect a state of tumor suppression, ie, the opposite of tumor escape. To examine this possibility, the author performed a literature search for measurements of cytokines in drug-naïve first episode subjects with schizophrenia for comparison with cytokine expression in tumor escape vs tumor suppression. The comparison showed that instead of either tumor suppression or escape, schizophrenia appears to be in a state of tumor equilibrium. Based on this finding, the author hypothesized that the clinical presentation of schizophrenia may involve cell transformation similar to an early stage of cancer initiation or an attenuated tumorigenesis. While this condition could reflect the presence of an actual tumor such as an ovarian teratoma causing anti-NMDA receptor encephalitis, it would only explain a small percentage of cases. To find a more likely tumor model, the author then compared the cytokine profile of schizophrenia to individual cancers and found the best match was melanoma. To demonstrate the viability of the theory, the author compared the hallmarks, emerging hallmarks, and enabling characteristics of melanoma to schizophrenia and found that many findings in schizophrenia are understood if schizophrenia is a condition of attenuated tumorigenesis.
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Affiliation(s)
- James S Brown
- Department of Psychiatry, VCU School of Medicine, Richmond, VA
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7
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Cheng Y, Yang B, Xi Y, Chen X. RAD51B as a potential biomarker for early detection and poor prognostic evaluation contributes to tumorigenesis of gastric cancer. Tumour Biol 2016; 37:14969-14978. [PMID: 27651161 DOI: 10.1007/s13277-016-5340-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/06/2016] [Indexed: 01/30/2023] Open
Abstract
Gastric cancer (GC) is a common and deadly disease worldwide. Outcomes of patients are poor largely due to chemoresistance or recurrence. Thus, identifying novel biomarkers to predict response to therapy and/or prognosis are urgently needed. RAD51B, a key player in DNA repair/recombination, has the potential to be a candidate oncogene and biomarker for cancer diagnosis and prognosis. However, its relationship with GC remains unclear. To evaluate clinicopathological and prognostic significance of RAD51B in GC, we examined messenger RNA (mRNA) and protein expression via quantitative real-time polymerase chain reaction (qRT-PCR) from 69 and tissue microarray from 144 GC patients, respectively. Our results showed that RAD51B mRNA expression was significantly up-regulated in tumors compared to that of matched noncancerous tissues (P < 0.001). In parallel, RAD51B protein showed a mainly nucleus-staining pattern, and the positive rate in tumors and stomach atypical hyperplasia was significantly higher than that in matched noncancerous tissues (P = 0.015). Moreover, high level of RAD51B protein was correlated with advanced stage (P = 0.009), aggressive differentiation (P = 0.022), and lymph node metastasis (P = 0.001). Further, Kaplan-Meier analysis indicated that patients with high level of RAD51B expression exhibited worse overall survival compared to patients with low level (P = 0.040). A multivariate Cox regression analysis suggested that RAD51B may be an independent prognostic factor for GC patients in Chinese population (P = 0.004). Additionally, functional studies indicated that over-expression of RAD51B promoted cell proliferation, aneuploidy, and drug resistance, while RAD51B knockdown led to G1 arrest and sensitized cells to 5-fluorouracil (5-FU). In conclusion, RAD51B may act as an oncogene during GC progression, and its hyper-expression may be a potential biomarker for early detection and poor prognosis of GC.
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Affiliation(s)
- Yikun Cheng
- Beijing New Oriental Foreign Language School at Yangzhou, Yangzhou, Jiangsu, 225006, China
| | - Bin Yang
- Department of Tumor Surgery, Shanxi Cancer Hospital, Taiyuan, Shanxi, 030001, People's Republic of China
| | - Yanfeng Xi
- Department of Pathology, Shanxi Cancer Hospital, Taiyuan, Shanxi, 030001, People's Republic of China.
| | - Xing Chen
- Department of Endoscopy, Shanxi Cancer Hospital, Taiyuan, Shanxi, 030001, China.
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8
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Zhang J, Xu K, Liu P, Geng Y, Wang B, Gan W, Guo J, Wu F, Chin YR, Berrios C, Lien EC, Toker A, DeCaprio JA, Sicinski P, Wei W. Inhibition of Rb Phosphorylation Leads to mTORC2-Mediated Activation of Akt. Mol Cell 2016; 62:929-942. [PMID: 27237051 DOI: 10.1016/j.molcel.2016.04.023] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/07/2015] [Accepted: 04/21/2016] [Indexed: 12/23/2022]
Abstract
The retinoblastoma (Rb) protein exerts its tumor suppressor function primarily by inhibiting the E2F family of transcription factors that govern cell-cycle progression. However, it remains largely elusive whether the hyper-phosphorylated, non-E2F1-interacting form of Rb has any physiological role. Here we report that hyper-phosphorylated Rb directly binds to and suppresses the function of mTORC2 but not mTORC1. Mechanistically, Rb, but not p107 or p130, interacts with Sin1 and blocks the access of Akt to mTORC2, leading to attenuated Akt activation and increased sensitivity to chemotherapeutic drugs. As such, inhibition of Rb phosphorylation by depleting cyclin D or using CDK4/6 inhibitors releases Rb-mediated mTORC2 suppression. This, in turn, leads to elevated Akt activation to confer resistance to chemotherapeutic drugs in Rb-proficient cells, which can be attenuated with Akt inhibitors. Therefore, our work provides a molecular basis for the synergistic usage of CDK4/6 and Akt inhibitors in treating Rb-proficient cancer.
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Affiliation(s)
- Jinfang Zhang
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Kai Xu
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, P.R. China.,Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Pengda Liu
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Yan Geng
- Department of Cancer Biology, Dana-Farber Cancer Institute and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Bin Wang
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.,Department of Gastroenterology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, 400042, P. R. China
| | - Wenjian Gan
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Jianping Guo
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Fei Wu
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.,Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, P.R. China
| | - Y Rebecca Chin
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Christian Berrios
- Department of Medical Oncology, Dana-Farber Cancer Institute and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA
| | - Evan C Lien
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Alex Toker
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - James A DeCaprio
- Department of Medical Oncology, Dana-Farber Cancer Institute and Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA
| | - Piotr Sicinski
- Department of Cancer Biology, Dana-Farber Cancer Institute and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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9
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Expression Analysis of Genes Involved in the RB/E2F Pathway in Astrocytic Tumors. PLoS One 2015; 10:e0137259. [PMID: 26317630 PMCID: PMC4552853 DOI: 10.1371/journal.pone.0137259] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 08/13/2015] [Indexed: 02/08/2023] Open
Abstract
Astrocytic gliomas, which are derived from glial cells, are considered the most common primary neoplasias of the central nervous system (CNS) and are histologically classified as low grade (I and II) or high grade (III and IV). Recent studies have shown that astrocytoma formation is the result of the deregulation of several pathways, including the RB/E2F pathway, which is commonly deregulated in various human cancers via genetic or epigenetic mechanisms. On the basis of the assumption that the study of the mechanisms controlling the INK4/ARF locus can help elucidate the molecular pathogenesis of astrocytic tumors, identify diagnostic and prognostic markers, and help select appropriate clinical treatments, the present study aimed to evaluate and compare methylation patterns using bisulfite sequencing PCR and evaluate the gene expression profile using real-time PCR in the genes CDKN2A, CDKN2B, CDC6, Bmi-1, CCND1, and RB1 in astrocytic tumors. Our results indicate that all the evaluated genes are not methylated independent of the tumor grade. However, the real-time PCR results indicate that these genes undergo progressive deregulation as a function of the tumor grade. In addition, the genes CDKN2A, CDKN2B, and RB1 were underexpressed, whereas CDC6, Bmi-1, and CCND1 were overexpressed; the increase in gene expression was significantly associated with decreased patient survival. Therefore, we propose that the evaluation of the expression levels of the genes involved in the RB/E2F pathway can be used in the monitoring of patients with astrocytomas in clinical practice and for the prognostic indication of disease progression.
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10
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Araki K, Kawauchi K, Hirata H, Yamamoto M, Taya Y. Cytoplasmic translocation of the retinoblastoma protein disrupts sarcomeric organization. eLife 2013; 2:e01228. [PMID: 24302570 PMCID: PMC3843810 DOI: 10.7554/elife.01228] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Skeletal muscle degeneration is a complication arising from a variety of chronic diseases including advanced cancer. Pro-inflammatory cytokine TNF-α plays a pivotal role in mediating cancer-related skeletal muscle degeneration. Here, we show a novel function for retinoblastoma protein (Rb), where Rb causes sarcomeric disorganization. In human skeletal muscle myotubes (HSMMs), up-regulation of cyclin-dependent kinase 4 (CDK4) and concomitant phosphorylation of Rb was induced by TNF-α treatment, resulting in the translocation of phosphorylated Rb to the cytoplasm. Moreover, induced expression of the nuclear exporting signal (NES)-fused form of Rb caused disruption of sarcomeric organization. We identified mammalian diaphanous-related formin 1 (mDia1), a potent actin nucleation factor, as a binding partner of cytoplasmic Rb and found that mDia1 helps maintain the structural integrity of the sarcomere. These results reveal a novel non-nuclear function for Rb and suggest a potential mechanism of TNF-α-induced disruption of sarcomeric organization. DOI:http://dx.doi.org/10.7554/eLife.01228.001 Skeletal muscles, such as the biceps and calves, are one of three main muscle groups in the body, and a range of chronic diseases—including cancer, heart disease and AIDS—can cause wasting and a loss of strength in these muscles. Many different cellular processes are known to be involved in the degeneration of skeletal muscle during illness. For example, in people suffering from cancer, the immune response produces large numbers of molecules called inflammatory cytokines to combat the cancer cells, and these molecules are thought to have a role in the breakdown of skeletal muscle. A cytokine called tumour necrosis factor alpha, or TNF-α for short, is thought to cause muscle damage, but the details of this process are not fully understood. One possibility is that TNF-α interacts with a protein called Rb—short for retinoblastoma protein—that suppresses the proliferation of cells that leads to cancer. However, if this protein is modified by a chemical process called phosphorylation, the Rb molecules will not be able to suppress the genes that lead to excessive cell growth. The hyperphosphorylation of Rb has been observed in many cancer cells, and it has been shown that high levels of TNF-α in cells results in Rb not working properly, but it has not been clear if faulty Rb also leads to the breakdown of skeletal muscle. Now Araki et al. provide evidence that the phosphorylation of Rb by TNF-α leads to skeletal muscle degeneration. Araki et al. found that in muscle cells that contain high concentrations of TNF-α, the Rb molecules move from the nuclei of the cells, where they interact with genes, to the cytoplasm, where they disrupt the formation of structural fibres. This means that Rb inhibits the ability of muscle cells to slide over one during contractions and relaxation, as happens in normal muscle tissue. If confirmed by further experiments, these results could lead to the development of new approaches for the treatment of skeletal muscle degeneration. DOI:http://dx.doi.org/10.7554/eLife.01228.002
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Affiliation(s)
- Keigo Araki
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
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11
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Cronin JC, Watkins-Chow DE, Incao A, Hasskamp JH, Schönewolf N, Aoude LG, Hayward NK, Bastian BC, Dummer R, Loftus SK, Pavan WJ. SOX10 ablation arrests cell cycle, induces senescence, and suppresses melanomagenesis. Cancer Res 2013; 73:5709-18. [PMID: 23913827 PMCID: PMC3803156 DOI: 10.1158/0008-5472.can-12-4620] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The transcription factor SOX10 is essential for survival and proper differentiation of neural crest cell lineages, where it plays an important role in the generation and maintenance of melanocytes. SOX10 is also highly expressed in melanoma tumors, but a role in disease progression has not been established. Here, we report that melanoma tumor cell lines require wild-type SOX10 expression for proliferation and SOX10 haploinsufficiency reduces melanoma initiation in the metabotropic glutamate receptor 1 (Grm1(Tg)) transgenic mouse model. Stable SOX10 knockdown in human melanoma cells arrested cell growth, altered cellular morphology, and induced senescence. Melanoma cells with stable loss of SOX10 were arrested in the G1 phase of the cell cycle, with reduced expression of the melanocyte determining factor microphthalmia-associated transcription factor, elevated expression of p21WAF1 and p27KIP2, hypophosphorylated RB, and reduced levels of its binding partner E2F1. As cell-cycle dysregulation is a core event in neoplastic transformation, the role for SOX10 in maintaining cell-cycle control in melanocytes suggests a rational new direction for targeted treatment or prevention of melanoma.
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Affiliation(s)
- Julia C. Cronin
- Genetic Disease Research Branch, National Human Genome Research Institute, Bethesda, MD
| | - Dawn E. Watkins-Chow
- Genetic Disease Research Branch, National Human Genome Research Institute, Bethesda, MD
| | - Art Incao
- Genetic Disease Research Branch, National Human Genome Research Institute, Bethesda, MD
| | - Joanne H. Hasskamp
- Maryland Melanoma Center at Medstar Franklin Square Medical Center, Baltimore, MD
| | - Nicola Schönewolf
- Department of Dermatology, University Hospital of Zurich, Zurich, Switzerland
| | - Lauren G. Aoude
- Queensland Institute of Medical Research, Oncogenomics Laboratory, Brisbane, Australia
| | - Nicholas K. Hayward
- Queensland Institute of Medical Research, Oncogenomics Laboratory, Brisbane, Australia
| | - Boris C. Bastian
- Helen Diller Family Comprehensive Cancer Center, UCSF, San Francisco, CA
| | - Reinhard Dummer
- Department of Dermatology, University Hospital of Zurich, Zurich, Switzerland
| | - Stacie K. Loftus
- Genetic Disease Research Branch, National Human Genome Research Institute, Bethesda, MD
| | - William J. Pavan
- Genetic Disease Research Branch, National Human Genome Research Institute, Bethesda, MD
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12
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Wierstra I. FOXM1 (Forkhead box M1) in tumorigenesis: overexpression in human cancer, implication in tumorigenesis, oncogenic functions, tumor-suppressive properties, and target of anticancer therapy. Adv Cancer Res 2013; 119:191-419. [PMID: 23870513 DOI: 10.1016/b978-0-12-407190-2.00016-2] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
FOXM1 (Forkhead box M1) is a typical proliferation-associated transcription factor and is also intimately involved in tumorigenesis. FOXM1 stimulates cell proliferation and cell cycle progression by promoting the entry into S-phase and M-phase. Additionally, FOXM1 is required for proper execution of mitosis. In accordance with its role in stimulation of cell proliferation, FOXM1 exhibits a proliferation-specific expression pattern and its expression is regulated by proliferation and anti-proliferation signals as well as by proto-oncoproteins and tumor suppressors. Since these factors are often mutated, overexpressed, or lost in human cancer, the normal control of the foxm1 expression by them provides the basis for deregulated FOXM1 expression in tumors. Accordingly, FOXM1 is overexpressed in many types of human cancer. FOXM1 is intimately involved in tumorigenesis, because it contributes to oncogenic transformation and participates in tumor initiation, growth, and progression, including positive effects on angiogenesis, migration, invasion, epithelial-mesenchymal transition, metastasis, recruitment of tumor-associated macrophages, tumor-associated lung inflammation, self-renewal capacity of cancer cells, prevention of premature cellular senescence, and chemotherapeutic drug resistance. However, in the context of urethane-induced lung tumorigenesis, FOXM1 has an unexpected tumor suppressor role in endothelial cells because it limits pulmonary inflammation and canonical Wnt signaling in epithelial lung cells, thereby restricting carcinogenesis. Accordingly, FOXM1 plays a role in homologous recombination repair of DNA double-strand breaks and maintenance of genomic stability, that is, prevention of polyploidy and aneuploidy. The implication of FOXM1 in tumorigenesis makes it an attractive target for anticancer therapy, and several antitumor drugs have been reported to decrease FOXM1 expression.
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13
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Rb/E2F1 regulates the innate immune receptor Toll-like receptor 3 in epithelial cells. Mol Cell Biol 2012; 32:1581-90. [PMID: 22310660 DOI: 10.1128/mcb.06454-11] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Tumor suppressor genes regulate the antiviral host defense through molecular mechanisms that are not yet well explored. Here, we show that the tumor suppressor retinoblastoma (Rb) protein positively regulates Toll-like receptor 3 (TLR3) expression, the sensing receptor for viral double-stranded RNA and poly(I · C). TLR3 expression was lower in Rb knockout (Rb(-/-)) mouse embryonic fibroblasts (MEF) and in mammalian epithelial cells transfected with Rb small-interfering RNA (siRNA) than in control cells. Consequently, induction of cytokines interleukin-8 and beta interferon after poly(I · C) stimulation was impaired in Rb(-/-) MEF and Rb siRNA-transfected cells compared to controls. TLR3 promoter analysis showed that Rb modulates the transcription factor E2F1, which directly binds to the proximal promoter of TLR3. Exogenous addition of E2F1 decreased TLR3 promoter activity, while Rb dose dependently curbed the effect of E2F1. Interestingly, poly(I · C) increased the Rb expression, and the poly(I · C)-induced TLR3 expression was impaired in Rb-depleted cells, suggesting the importance of Rb in TLR3 induction by poly(I · C). Together, these data indicated that E2F1 suppresses TLR3 transcription, but during immune stimulation, Rb is upregulated to block the inhibitory effect of E2F1 on TLR3, highlighting a role of Rb-E2F1 axis in the innate immune response in epithelial cells.
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14
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Matsumoto A, Takeishi S, Kanie T, Susaki E, Onoyama I, Tateishi Y, Nakayama K, Nakayama KI. p57 is required for quiescence and maintenance of adult hematopoietic stem cells. Cell Stem Cell 2011; 9:262-71. [PMID: 21885021 DOI: 10.1016/j.stem.2011.06.014] [Citation(s) in RCA: 233] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Revised: 06/01/2011] [Accepted: 06/27/2011] [Indexed: 12/25/2022]
Abstract
Quiescence is required for the maintenance of hematopoietic stem cells (HSCs). Members of the Cip/Kip family of cyclin-dependent kinase (CDK) inhibitors (p21, p27, p57) have been implicated in HSC quiescence, but loss of p21 or p27 in mice affects HSC quiescence or functionality only under conditions of stress. Although p57 is the most abundant family member in quiescent HSCs, its role has remained uncharacterized. Here we show a severe defect in the self-renewal capacity of p57-deficient HSCs and a reduction of the proportion of the cells in G(0) phase. Additional ablation of p21 in a p57-null background resulted in a further decrease in the colony-forming activity of HSCs. Moreover, the HSC abnormalities of p57-deficient mice were corrected by knocking in the p27 gene at the p57 locus. Our results therefore suggest that, among Cip/Kip family CDK inhibitors, p57 plays a predominant role in the quiescence and maintenance of adult HSCs.
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Affiliation(s)
- Akinobu Matsumoto
- Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan
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15
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Nijwening JH, Geutjes EJ, Bernards R, Beijersbergen RL. The histone demethylase Jarid1b (Kdm5b) is a novel component of the Rb pathway and associates with E2f-target genes in MEFs during senescence. PLoS One 2011; 6:e25235. [PMID: 21980403 PMCID: PMC3181323 DOI: 10.1371/journal.pone.0025235] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 08/29/2011] [Indexed: 12/12/2022] Open
Abstract
Senescence is a robust cell cycle arrest controlled by the p53 and Rb pathways that acts as an important barrier to tumorigenesis. Senescence is associated with profound alterations in gene expression, including stable suppression of E2f-target genes by heterochromatin formation. Some of these changes in chromatin composition are orchestrated by Rb. In complex with E2f, Rb recruits chromatin modifying enzymes to E2f target genes, leading to their transcriptional repression. To identify novel chromatin remodeling enzymes that specifically function in the Rb pathway, we used a functional genetic screening model for bypass of senescence in murine cells. We identified the H3K4-demethylase Jarid1b as novel component of the Rb pathway in this screening model. We find that depletion of Jarid1b phenocopies knockdown of Rb1 and that Jarid1b associates with E2f-target genes during cellular senescence. These results suggest a role for Jarid1b in Rb-mediated repression of cell cycle genes during senescence.
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Affiliation(s)
- Jeroen H. Nijwening
- Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Ernst-Jan Geutjes
- Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Rene Bernards
- Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Roderick L. Beijersbergen
- Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, The Netherlands
- * E-mail:
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16
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Cohen-Solal KA, Merrigan KT, Chan JLK, Goydos JS, Chen W, Foran DJ, Liu F, Lasfar A, Reiss M. Constitutive Smad linker phosphorylation in melanoma: a mechanism of resistance to transforming growth factor-β-mediated growth inhibition. Pigment Cell Melanoma Res 2011; 24:512-24. [PMID: 21477078 DOI: 10.1111/j.1755-148x.2011.00858.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Melanoma cells are resistant to transforming growth factor-β (TGFβ)-induced cell-cycle arrest. In this study, we investigated a mechanism of resistance involving a regulatory domain, called linker region, in Smad2 and Smad3, main downstream effectors of TGFβ. Melanoma cells in culture and tumor samples exhibited constitutive Smad2 and Smad3 linker phosphorylation. Treatment of melanoma cells with the MEK1/2 inhibitor, U0126, or the two pan-CDK and GSK3 inhibitors, Flavopiridol and R547, resulted in decreased linker phosphorylation of Smad2 and Smad3. Overexpression of the linker phosphorylation-resistant Smad3 EPSM mutant in melanoma cells resulted in an increase in expression of p15(INK4B) and p21(WAF1) , as compared with cells transfected with wild-type (WT) Smad3. In addition, the cell numbers of EPSM Smad3-expressing melanoma cells were significantly reduced compared with WT Smad3-expressing cells. These results suggest that the linker phosphorylation of Smad3 contributes to the resistance of melanoma cells to TGFβ-mediated growth inhibition.
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Affiliation(s)
- Karine A Cohen-Solal
- Department of Medicine, Division of Medical Oncology, UMDNJ-Robert Wood Johnson Medical School, the Cancer Institute of New Jersey, New Brunswick, NJ, USA.
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17
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Singh S, Davis R, Alamanda V, Pireddu R, Pernazza D, Sebti S, Lawrence N, Chellappan S. Rb-Raf-1 interaction disruptor RRD-251 induces apoptosis in metastatic melanoma cells and synergizes with dacarbazine. Mol Cancer Ther 2010; 9:3330-41. [PMID: 21139044 DOI: 10.1158/1535-7163.mct-10-0442] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Metastatic melanoma is an aggressive cancer with very low response rate against conventional chemotherapeutic agents such as dacarbazine (DTIC). Inhibitor of Rb-Raf-1 interaction RRD-251 was tested against the melanoma cell lines SK-MEL-28, SK-MEL-5, and SK-MEL-2. RRD-251 was found to be a potent inhibitor of melanoma cell proliferation, irrespective of V600E B-Raf mutation status of the cell lines. In a SK-MEL-28 xenograft experiment, RRD-251 exerted a significant suppression of tumor growth compared with vehicle (P = 0.003). Similar to in vitro effects, tumors from RRD-251-treated animals showed decreased Rb-Raf-1 interaction in vivo. Growth suppressive effects of RRD-251 were associated with induction of apoptosis as well as a G(1) arrest, with an accompanying decrease in S-phase cells. RRD-251 inhibited Rb phosphorylation and downregulated E2F1 protein levels in these cells. Real-time PCR analysis showed that RRD-251 caused downregulation of cell-cycle regulatory genes thymidylate synthase (TS) and cdc6 as well as the antiapoptotic gene Mcl-1. Combinatorial treatment of RRD-251 and DTIC resulted in a significantly higher apoptosis in DTIC resistant cell lines SK-MEL-28 and SK-MEL-5, as revealed by increased caspase-3 activity and PARP cleavage. Because aberrant Rb/E2F pathway is associated with melanoma progression and resistance to apoptosis, these results suggest that the Rb-Raf-1 inhibitor could be an effective agent for melanoma treatment, either alone or in combination with DTIC.
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Affiliation(s)
- Sandeep Singh
- Drug Discovery Department, H Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612, USA
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18
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Lasfar A, Cohen-Solal KA. Resistance to transforming growth factor β-mediated tumor suppression in melanoma: are multiple mechanisms in place? Carcinogenesis 2010; 31:1710-7. [PMID: 20656791 DOI: 10.1093/carcin/bgq155] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Resistance to transforming growth factor (TGF) β-mediated tumor suppression in melanoma appears to be a crucial step in tumor aggressiveness since it is usually coupled with the ability of TGFβ to drive the oncogenic process via autocrine and paracrine effects. In this review, we will focus mainly on the mechanisms of escape from TGFβ-induced cell cycle arrest because the mechanisms of resistance to TGFβ-mediated apoptosis are still essentially speculative. As expected, some of these mechanisms can directly affect the function of the main downstream effectors of TGFβ, Smad2 and Smad3, resulting in compromised Smad-mediated antiproliferative activity. Other mechanisms can counteract or overcome TGFβ-mediated cell cycle arrest independently of the Smads. In melanoma, some models of resistance to TGFβ have been suggested and will be described. In addition, we propose additional models of resistance taking into consideration the information available on the dysregulation of fundamental cellular effectors and signaling pathways in melanoma.
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Affiliation(s)
- Ahmed Lasfar
- Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, University Hospital Cancer Center, 205 South Orange Avenue, Newark, NJ 07103, USA
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19
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Li J, Xu M, Yang Z, Li A, Dong J. Simultaneous Inhibition of MEK and CDK4 Leads to Potent Apoptosis in Human Melanoma Cells. Cancer Invest 2010. [DOI: 10.1080/07357900903286966] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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20
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Dos Reis Vasques L, Pujiz RS, Strauss BE, Krieger JE. Knockdown of E2f1 by RNA interference impairs proliferation of rat cells in vitro. Genet Mol Biol 2010; 33:17-22. [PMID: 21637599 PMCID: PMC3036082 DOI: 10.1590/s1415-47572009005000104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Accepted: 08/08/2009] [Indexed: 01/22/2023] Open
Abstract
E2F1 plays a key role in cell-cycle regulation in mammals, since its transcription factor activity controls genes required for DNA synthesis and apoptosis. E2F1 deregulation is a common feature among different tumor types and can be a major cause of cell proliferation. Thus, blocking E2F1 expression by RNA interference represents a promising therapeutic approach. In this study, the introduction of specific short hairpin RNAs (shRNAs) reduced E2f1 expression by up to 77%, and impaired rat glioma cell proliferation by approximately 70%, as compared to control cells. Furthermore, we investigated the expression of E2f1 target genes, Cyclin A and Cyclin E. Cyclin A was found to be down-regulated, whereas Cyclin E had similar expression to control cells, indicating that gene(s) other than E2f1 control its transcription. Other E2f family members, E2f2 and E2f3, which have been classified in the same subgroup of transcriptional activators, were also analyzed. Expression of both E2f2 and E2f3 was similar to control cells, showing no cross-inactivation or up-regulation to compensate for the absence of E2f1. Nevertheless, their expression was insufficient to maintain the initial proliferation potential. Taken together, our results suggest that shE2f1 is a promising therapy to control tumor cell proliferation.
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Wackernagel W, Schneider M, Mayer C, Langmann G, Singh AD. Genetik des Aderhautmelanoms. SPEKTRUM DER AUGENHEILKUNDE 2009. [DOI: 10.1007/s00717-009-0360-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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22
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Hersey P, Bastholt L, Chiarion-Sileni V, Cinat G, Dummer R, Eggermont AMM, Espinosa E, Hauschild A, Quirt I, Robert C, Schadendorf D. Small molecules and targeted therapies in distant metastatic disease. Ann Oncol 2009; 20 Suppl 6:vi35-40. [PMID: 19617296 PMCID: PMC2712592 DOI: 10.1093/annonc/mdp254] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Chemotherapy, biological agents or combinations of both have had little impact on survival of patients with metastatic melanoma. Advances in understanding the genetic changes associated with the development of melanoma resulted in availability of promising new agents that inhibit specific proteins up-regulated in signal cell pathways or inhibit anti-apoptotic proteins. Sorafenib, a multikinase inhibitor of the RAF/RAS/MEK pathway, elesclomol (STA-4783) and oblimersen (G3139), an antisense oligonucleotide targeting anti-apoptotic BCl-2, are in phase III clinical studies in combination with chemotherapy. Agents targeting mutant B-Raf (RAF265 and PLX4032), MEK (PD0325901, AZD6244), heat-shock protein 90 (tanespimycin), mTOR (everolimus, deforolimus, temsirolimus) and VEGFR (axitinib) showed some promise in earlier stages of clinical development. Receptor tyrosine-kinase inhibitors (imatinib, dasatinib, sunitinib) may have a role in treatment of patients with melanoma harbouring c-Kit mutations. Although often studied as single agents with disappointing results, new targeted drugs should be more thoroughly evaluated in combination therapies. The future of rational use of new targeted agents also depends on successful application of analytical techniques enabling molecular profiling of patients and leading to selection of likely therapy responders.
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Affiliation(s)
- P Hersey
- Immunology and Oncology Unit, Calvary Mater Newcastle Hospital, New South Wales, Australia.
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Haferkamp S, Tran SL, Becker TM, Scurr LL, Kefford RF, Rizos H. The relative contributions of the p53 and pRb pathways in oncogene-induced melanocyte senescence. Aging (Albany NY) 2009; 1:542-56. [PMID: 20157537 PMCID: PMC2806033 DOI: 10.18632/aging.100051] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Accepted: 05/15/2009] [Indexed: 02/06/2023]
Abstract
Oncogene-induced
senescence acts as a barrier against tumour formation and has been
implicated as the mechanism preventing the transformation of benign
melanocytic lesions that frequently harbour oncogenic B-RAF or N-RAS mutations.
In
the present study we systematically assessed the relative importance
of the tumour suppressor proteins p53, p21Waf1, pRb
and p16INK4a in mediating oncogene-induced senescence in human
melanocytes.
We now show
that oncogenic N-RAS induced senescence in melanocytes is
associated with DNA damage, a potent DNA damage response and the activation
of both the p16INK4a/pRb and p53/p21Waf1 tumour
suppressor pathways. Surprisingly neither the
pharmacological inhibition of the DNA damage response pathway nor silencing of
p53 expression had any detectable impact on oncogene-induced senescence in
human melanocytes. Our data indicate that the pRb pathway is
the dominant effector of senescence in these cells, as its specific
inactivation delays the onset of senescence and weakens oncogene-induced
proliferative arrest. Furthermore, we show that although both p16INK4a
and p21Waf1 are upregulated in response to N-RASQ61K,
the activities of these CDK inhibitors are clearly distinct and only the
loss of p16INK4a weakens senescence. We propose that the ability
of p16INK4a to inhibit the cyclin D-dependent kinases and DNA
replication, functions not shared by p21Waf1, contribute to its
role in senescence. Thus, in melanocytes with oncogenic signalling only p16INK4a
can fully engage the pRb pathway to alter chromatin structure and
silence the genes that are required for proliferation.
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Affiliation(s)
- Sebastian Haferkamp
- Westmead Institute for Cancer Research and Melanoma Institute of Australia, University of Sydney at Westmead, Westmead NSW 2145, Australia
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24
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Keeping things quiet: roles of NuRD and Sin3 co-repressor complexes during mammalian development. Int J Biochem Cell Biol 2008; 41:108-16. [PMID: 18775506 DOI: 10.1016/j.biocel.2008.07.022] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 07/23/2008] [Accepted: 07/24/2008] [Indexed: 01/05/2023]
Abstract
Gene inactivation studies of mammalian histone and DNA-modifying proteins have demonstrated a role for many such proteins in embryonic development. Post-implantation embryonic lethality implies a role for epigenetic factors in differentiation and in development of specific lineages or tissues. However a handful of chromatin-modifying enzymes have been found to be required in pre- or peri-implantation embryos. This is significant as implantation is the time when inner cell mass cells of the blastocyst exit pluripotency and begin to commit to form the various lineages that will eventually form the adult animal. These observations indicate a critical role for chromatin-modifying proteins in the earliest lineage decisions of mammalian development, and/or in the formation of the first embryonic cell types. Recent work has shown that the two major class I histone deacetylase-containing co-repressor complexes, the NuRD and Sin3 complexes, are both required at peri-implantation stages of mouse development, demonstrating the importance of histone deacetylation in cell fate decisions. Over the past 10 years both genetic and biochemical studies have revealed surprisingly divergent roles for these two co-repressors in mammalian cells. In this review we will summarise the evidence that the two major class I histone deacetylase complexes in mammalian cells, the NuRD and Sin3 complexes, play important roles in distinct aspects of embryonic development.
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25
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Ha L, Merlino G, Sviderskaya EV. Melanomagenesis: overcoming the barrier of melanocyte senescence. Cell Cycle 2008; 7:1944-8. [PMID: 18604170 PMCID: PMC2678050 DOI: 10.4161/cc.7.13.6230] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Although melanoma ultimately progresses to a highly aggressive and metastatic disease that is typically resistant to currently available therapy, it often begins as a benign nevus consisting of a clonal population of hyperplastic melanocytes that cannot progress because they are locked in a state of cellular senescence. Once senescence is overcome, the nevus can exhibit dysplastic features and readily progress to more lethal stages. Recent advances have convincingly demonstrated that senescence represents a true barrier to the progression of many types of cancer, including melanoma. Thus, understanding the mechanism(s) by which melanoma evades senescence has become a priority in the melanoma research community. Senescence in most cells is regulated through some combination of activities within the RB and p53 pathways. However, differences discovered among various tumor types, some subtle and others quite profound, have revealed that senescence frequently operates in a context-dependent manner. Here we review what is known about melanocyte senescence, and how such knowledge may provide a much-needed edge in our struggles to contain or perhaps vanquish this often-fatal malignancy.
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Affiliation(s)
- Linan Ha
- Division of Monoclonal Antibody, Center of Drug Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, USA
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26
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Abbas S, Bhoumik A, Dahl R, Vasile S, Krajewski S, Cosford NDP, Ronai ZA. Preclinical studies of celastrol and acetyl isogambogic acid in melanoma. Clin Cancer Res 2008; 13:6769-78. [PMID: 18006779 DOI: 10.1158/1078-0432.ccr-07-1536] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Sensitize melanomas to apoptosis and inhibit their growth and metastatic potential by compounds that mimic the activities of activating transcription factor 2 (ATF2)-driven peptides. EXPERIMENTAL DESIGN Small-molecule chemical library consisting of 3,280 compounds was screened to identify compounds that elicit properties identified for ATF2 peptide, including (a) sensitization of melanoma cells to apoptosis, (b) inhibition of ATF2 transcriptional activity, (c) activation of c-Jun NH(2)-terminal kinase (JNK) and c-Jun transcriptional activity, and (d) inhibition of melanoma growth and metastasis in mouse models. RESULTS Two compounds, celastrol (CSL) and acetyl isogambogic acid, could, within a low micromolar range, efficiently elicit cell death in melanoma cells. Both compounds efficiently inhibit ATF2 transcriptional activities, activate JNK, and increase c-Jun transcriptional activities. Similar to the ATF2 peptide, both compounds require JNK activity for their ability to inhibit melanoma cell viability. Derivatives of CSL were identified as potent inducers of cell death in mouse and human melanomas. CSL and a derivative (CA19) could also efficiently inhibit growth of human and mouse melanoma tumors and reduce the number of lung metastases in syngeneic and xenograft mouse models. CONCLUSIONS These studies show for the first time the effect of CSL and acetyl isogambogic acid on melanoma. These compounds elicit activities that resemble the well-characterized ATF2 peptide and may therefore offer new approaches for the treatment of this tumor type.
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Affiliation(s)
- Sabiha Abbas
- Signal Transduction Program, Cancer Center, Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
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27
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Roesch A, Mueller AM, Stempfl T, Moehle C, Landthaler M, Vogt T. RBP2-H1/JARID1B is a transcriptional regulator with a tumor suppressive potential in melanoma cells. Int J Cancer 2008; 122:1047-57. [PMID: 17973255 DOI: 10.1002/ijc.23211] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The RBP2-H1/JARID1B nuclear protein belongs to the ARID family of DNA-binding proteins and is a potential tumor suppressor that is lost during melanoma development. As we have recently shown, one physiological function of RBP2-H1/JARID1B is to exert cell cycle control via maintenance of active retinoblastoma protein. We now add new evidence that RBP2-H1/JARID1B can also directly regulate gene transcription in a reporter assay system, either alone or as part of a multimolecular complex together with the developmental transcription factors FOXG1b and PAX9. In melanoma cells, chromatin immunoprecipitation combined with promoter chip analysis (ChIP-on-chip) suggests a direct binding of re-expressed RBP2-H1/JARID1B to a multitude of human regulatory chromosomal elements (promoters, enhancers and introns). Among those, a set of 23 genes, including the melanoma relevant genes CDK6 and JAG-1 could be confirmed by cDNA microarray analyses to be differentially expressed after RBP2-H1/JARID1B re-expression. In contrast, in nonmelanoma HEK 293 cells, RBP2-H1/JARID1B overexpression only evokes a minor transcriptional response in cDNA microarray analyses. Because the transcriptional regulation in melanoma cells is accompanied by an inhibition of proliferation, an increase in caspase activity and a partial cell cycle arrest in G1/0, our data support an anti-tumorigenic role of RBP2-H1/JARID1B in melanocytic cells.
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Affiliation(s)
- Alexander Roesch
- Department of Dermatology, Regensburg University Medical Center, D-93053 Regensburg, Germany.
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28
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Hersey P, Zhang XD, Mhaidat N. Overcoming Resistance to Apoptosis in Cancer Therapy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 615:105-26. [DOI: 10.1007/978-1-4020-6554-5_6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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29
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Raj D, Liu T, Samadashwily G, Li F, Grossman D. Survivin repression by p53, Rb and E2F2 in normal human melanocytes. Carcinogenesis 2007; 29:194-201. [PMID: 17916908 DOI: 10.1093/carcin/bgm219] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The inhibitor of apoptosis protein survivin is a dual mediator of apoptosis resistance and cell cycle progression and is highly expressed in cancer. We have shown previously that survivin is up-regulated in melanoma compared with normal melanocytes, is required for melanoma cell viability, and that melanocyte expression of survivin predisposes mice to ultraviolet-induced melanoma and metastasis. The mechanism of survivin up-regulation in the course of melanocyte transformation and its repression in normal melanocytes, however, has not been clearly defined. We show here that p53 and retinoblastoma (Rb), at basal levels and in the absence of any activating stimuli, are both required to repress survivin transcription in normal human melanocytes. Survivin repression in melanocytes does not involve alterations in protein stability or promoter methylation. p53 and Rb (via E2Fs) regulate survivin expression by direct binding to the survivin promoter; p53 also affects survivin expression by activating p21. We demonstrate a novel role for E2F2 in the negative regulation of survivin expression. In addition, we identify a novel E2F-binding site in the survivin promoter and show that mutation of either the p53- or E2F-binding sites is sufficient to increase promoter activity. These studies suggest that compromise of either p53 or Rb pathways during melanocyte transformation leads to up-regulation of survivin expression in melanoma.
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Affiliation(s)
- Deepak Raj
- Department of Dermatology, University of Utah, 30 North 1900 East, Salt Lake City, UT 84132, USA
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Ha L, Ichikawa T, Anver M, Dickins R, Lowe S, Sharpless NE, Krimpenfort P, DePinho RA, Bennett DC, Sviderskaya EV, Merlino G. ARF functions as a melanoma tumor suppressor by inducing p53-independent senescence. Proc Natl Acad Sci U S A 2007; 104:10968-73. [PMID: 17576930 PMCID: PMC1904138 DOI: 10.1073/pnas.0611638104] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Inactivation of the p53 pathway represents the most common molecular defect of human cancer. But in the setting of melanoma, a highly aggressive and invariably fatal malignancy in its advanced disseminated form, mutation/deletion of p53 is relatively rare, whereas its positive regulator ARF is often lost. Here, we show that genetic deficiency in Arf but not p53 facilitates rapid development of melanoma in a genetically engineered mouse model. This difference is accounted for, at least in part, by the unanticipated observation that, unlike fibroblasts, senescence control in melanocytes is strongly regulated by Arf and not p53. Moreover, oncogenic NRAS collaborates with deficiency in Arf, but not p53, to fully transform melanocytes. Our data demonstrate that ARF and p53, although linked in a common pathway, suppress tumorigenesis through distinct, lineage-dependent mechanisms and suggest that ARF helps restrict melanoma progression by executing the oncogene-induced senescence program in benign nevi. Thus, therapeutics designed to restore wild-type p53 function may be insufficient to counter melanoma and other malignancies in which ARF holds p53-independent tumor suppressor activity.
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Affiliation(s)
- Linan Ha
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, Bethesda, MD 20892-4264
| | - Takeshi Ichikawa
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, Bethesda, MD 20892-4264
| | - Miriam Anver
- Pathology/Histotechnology Laboratory, SAIC, National Cancer Institute–Frederick Cancer Research and Development Center, Frederick, MD 21702
| | - Ross Dickins
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Scott Lowe
- Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Norman E. Sharpless
- Departments of Medicine and Genetics, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Paul Krimpenfort
- Division of Molecular Genetics, The Netherlands Cancer Institute, 1066 CX, Amsterdam, The Netherlands
| | - Ronald A. DePinho
- Departments of Medical Oncology, Medicine, and Genetics, Center for Applied Cancer Science, and Belfer Foundation Institute for Innovative Cancer Science, Dana–Farber Cancer Institute, Harvard Medical School, Boston, MA 02115; and
| | - Dorothy C. Bennett
- Division of Basic Medical Sciences, St. George's, University of London, London SW17 0RE, United Kingdom
| | - Elena V. Sviderskaya
- Division of Basic Medical Sciences, St. George's, University of London, London SW17 0RE, United Kingdom
- To whom correspondence may be addressed. E-mail: or
| | - Glenn Merlino
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, Bethesda, MD 20892-4264
- To whom correspondence may be addressed. E-mail: or
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Abstract
The incidence of melanoma is increasing at one of the highest rates of any form of cancer in the United States, with the current lifetime risk being one in 68. At present, there are limited systemic therapies to treat advanced stages of melanoma, and the key to improved survival remains early detection. Recent discoveries have allowed for a clearer picture of the molecular events leading to melanoma development and progression. Since identifying prevalent activating mutations of the BRAF kinase in melanomas, there has been a flood of additional molecular studies to further clarify the role of this pathway and others in melanomagenesis. In particular, recent genetic studies have demonstrated specific genotype-phenotype correlations that provide the first major insights into the molecular subclassification of melanoma and the heterogeneous nature of this malignancy. In this article, we review the most up-to-date molecular discoveries in melanoma biology and provide a framework for understanding their significance in melanoma development and progression. We also provide details on the development of novel therapies based on these recent molecular discoveries and insight into current and planned clinical trials. It is expected that these latest studies in melanoma will help define the critical molecular events involved in disease onset and progression and allow us to move rapidly toward a true molecular classification. We eagerly anticipate rationally designed melanoma therapies based on such a classification scheme and the associated improvements in patient outcomes.
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Affiliation(s)
- Leslie A Fecher
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, USA
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Mathivanan J, Rohini K, Gope ML, Anandh B, Gope R. Altered structure and deregulated expression of the tumor suppressor gene retinoblastoma (RB1) in human brain tumors. Mol Cell Biochem 2007; 302:67-77. [PMID: 17318405 DOI: 10.1007/s11010-007-9428-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Accepted: 02/02/2007] [Indexed: 12/24/2022]
Abstract
A total of 40 human brain tumor samples were analyzed for tumor-specific alterations at the RB1 gene locus. Gliomas were more prevalent in younger males and meningiomas in older females. Southern blot analysis revealed loss of heterozygosity (LOH) at the intron 1 locus of RB1 gene in 19.4% of informative cases and this is the first report showing LOH at this locus in human brain tumors. Levels of RB1 mRNA and protein, pRb, and the percentage of hyperphosphorylated form of pRb were also analyzed in these tumors. Normal human fibroblast cell line WI38 was used as control in northern and western analysis. Normal sized RB1 mRNA and protein were present in all the tumor samples. Majority of the gliomas had 2.0-fold or higher levels of RB1 mRNA and most meningiomas had less than 2.0-fold of RB1 mRNA compared to control WI38 cells. The total pRb levels were 2.0-fold or higher in all the tumor samples compared to control. More than 50% of pRb existed in hyperphosphorylated form in all gliomas except two. However, six out of 13 meningiomas had less than 50% of total pRb in the hyperphosphorylated form. These results indicate that the increased percentage of hyperphosphorylated form of pRb in gliomas could provide growth advantage to these tumors. Presence of LOH at the RB1 gene locus and the increased levels of RB1 RNA and protein and increased percentage of hyperphosphorylated form of pRb are indicative of an overall deregulation of pRb pathway in human brain tumors.
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Affiliation(s)
- J Mathivanan
- Department of Human Genetics, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, 560 029, India
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Felsani A, Mileo AM, Maresca V, Picardo M, Paggi MG. New technologies used in the study of human melanoma. INTERNATIONAL REVIEW OF CYTOLOGY 2007; 261:247-86. [PMID: 17560284 DOI: 10.1016/s0074-7696(07)61006-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The amount of information on tumor biology has expanded enormously, essentially due to the completion of the human genome sequencing and to the application of new technologies that represent an exciting breakthrough in molecular analysis. Often these data spring from experimental procedures, such as a serial analysis of gene expression (SAGE) and DNA microarrays, which cannot be defined as hypothesis-driven: it may appear to be a "brute force" approach through which no information can be directly generated concerning the specific functions of selected genes in a definite context. However, interesting results are fruitfully generated, and thus it is important to consider the enormous potential these new technologies possess and to learn how to apply this novel form of knowledge in the emerging field of molecular medicine. This review, after a limited outline regarding several classic aspects of human cutaneous melanoma biology, genetics, and clinical approaches, will focus on the proficient use of up-to-date technologies in the study of the neoplastic disease and on their capability to provide effective support to conventional approaches in melanoma diagnosis, prognosis, and treatment.
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Affiliation(s)
- Armando Felsani
- CNR, Istituto di Neurobiologia e Medicina Molecolare, 00143 Rome, Italy
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35
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Li Y, Xie M, Yang J, Yang D, Deng R, Wan Y, Yan B. The expression of antiapoptotic protein survivin is transcriptionally upregulated by DEC1 primarily through multiple sp1 binding sites in the proximal promoter. Oncogene 2006; 25:3296-306. [PMID: 16462771 PMCID: PMC4114758 DOI: 10.1038/sj.onc.1209363] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Human differentially expressed in chondrocytes (DEC), mouse stimulated with retinoic acid and rat split and hairy related proteins constitute a structurally distinct class of the basic helix-loop-helix proteins. DEC1 is abundantly expressed in tumors and protects against apoptosis induced by serum starvation. In this study, we report that DEC1 antiapoptosis is achieved by inducing survivin, an antiapoptotic protein. In paired tumor-normal tissues, survivin and DEC1 exhibited a paralleled expression pattern. Tetracycline-induced expression of DEC1 in stable lines proportionally increased the expression of survivin. In reporter assays, DEC1 transactivated the survivin promoter but repressed the DEC2 promoter. In contrast to the repression, the activation was delayed and varied depending on serum concentrations and cycle blockers. Studies with reporter mutants located, in the survivin promoter, two Sp1 sites that supported DEC1 transactivation. Electrophoretic mobility shift assay and chromatin immunoprecipitation detected the presence of DEC1 in the survivin promoter. These findings establish that the survivin gene is a transcription target of DEC1, and induction of survivin is at least in part responsible for DEC1 antiapoptosis.
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Affiliation(s)
- Y Li
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - M Xie
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - J Yang
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - D Yang
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - R Deng
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Y Wan
- Department of Biology, Providence College, Providence, RI 02908, USA
| | - B Yan
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
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