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Fisher RP. Cdk7: a kinase at the core of transcription and in the crosshairs of cancer drug discovery. Transcription 2019; 10:47-56. [PMID: 30488763 PMCID: PMC6602562 DOI: 10.1080/21541264.2018.1553483] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/20/2018] [Accepted: 11/20/2018] [Indexed: 12/22/2022] Open
Abstract
The transcription cycle of RNA polymerase II (Pol II) is regulated by a set of cyclin-dependent kinases (CDKs). Cdk7, associated with the transcription initiation factor TFIIH, is both an effector CDK that phosphorylates Pol II and other targets within the transcriptional machinery, and a CDK-activating kinase (CAK) for at least one other essential CDK involved in transcription. Recent studies have illuminated Cdk7 functions that are executed throughout the Pol II transcription cycle, from promoter clearance and promoter-proximal pausing, to co-transcriptional chromatin modification in gene bodies, to mRNA 3´-end formation and termination. Cdk7 has also emerged as a target of small-molecule inhibitors that show promise in the treatment of cancer and inflammation. The challenges now are to identify the relevant targets of Cdk7 at each step of the transcription cycle, and to understand how heightened dependence on an essential CDK emerges in cancer, and might be exploited therapeutically.
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Affiliation(s)
- Robert P. Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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52
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Hur JY, Kim HR, Lee JY, Park S, Hwang JA, Kim WS, Yoon S, Choi CM, Rho JK, Lee JC. CDK7 inhibition as a promising therapeutic strategy for lung squamous cell carcinomas with a SOX2 amplification. Cell Oncol (Dordr) 2019; 42:449-458. [PMID: 30838525 DOI: 10.1007/s13402-019-00434-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/15/2019] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Despite the development of molecular targeted therapies, few advances have been made in the treatment of lung squamous cell carcinoma (SCC). SOX2 amplification is one of the most common genetic alterations in SCC. Here, we investigated the effects of THZ1, a potent cyclin-dependent kinase 7 (CDK7) inhibitor that plays a key role in gene transcription, in SCC. METHODS Lung SCC-derived cell viabilities were assessed using a CCK-8 assay. SOX2 expression and RNAPII-CTD phosphorylation levels after THZ1 treatment were determined by Western blotting. The effect of SOX2 suppression using shRNA was assessed by flow cytometry. Gene expression patterns after THZ1 treatment of lung SCC-derived cells were identified using microarray-based mRNA profiling. RESULTS We found that THZ1 treatment led to suppression of cell growth and apoptotic cell death in SOX2-amplified SCC-derived cells only, whereas the modest growth-inhibitory effect of cisplatin did not differ according to SOX2 amplification status. We also found that THZ1 decreased the phosphorylation of the carboxyl-terminal domain of RNA polymerase II and the expression of several genes. Specifically, we found that the expression of transcription-associated genes, including SOX2, was down-regulated by THZ1 in SOX2-amplified SCC cells. This inhibition of SOX2 expression resulted in suppression of the growth of these cells. CONCLUSIONS From our data, we conclude that THZ1 may effectively control the proliferation and survival of SOX2-amplified SCC cells through a decrease in global transcriptional activity, suggesting that CDK7 inhibition leading to transcription suppression may be a promising therapeutic option for lung SCC with a SOX2 amplification.
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Affiliation(s)
- Jae Young Hur
- Asan Institute for Life Sciences, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
- Lung Cancer Center & Department of Pathology, Konkuk University Medical Center, Seoul, South Korea
| | - Hyeong Ryul Kim
- Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - Jung Yeon Lee
- Department of Internal Medicine, Graduate School, Chungbuk National University, Cheongju, South Korea
| | - Sojung Park
- Department of Pulmonology and Critical Care Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - Ji An Hwang
- Department of Pulmonology and Critical Care Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - Woo Sung Kim
- Department of Pulmonology and Critical Care Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
| | - Shinkyo Yoon
- Department of Oncology, Asan Medical Center, College of Medicine, University of Ulsan, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Chang-Min Choi
- Department of Pulmonology and Critical Care Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, South Korea
- Department of Oncology, Asan Medical Center, College of Medicine, University of Ulsan, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea
| | - Jin Kyung Rho
- Department of Convergence Medicine, Asan Medical Center, College of Medicine, University of Ulsan, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea.
| | - Jae Cheol Lee
- Department of Oncology, Asan Medical Center, College of Medicine, University of Ulsan, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea.
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Kolesnikova O, Radu L, Poterszman A. TFIIH: A multi-subunit complex at the cross-roads of transcription and DNA repair. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 115:21-67. [PMID: 30798933 DOI: 10.1016/bs.apcsb.2019.01.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Transcription factor IIH (TFIIH) is a multiprotein complex involved in both eukaryotic transcription and DNA repair, revealing a tight connection between these two processes. Composed of 10 subunits, it can be resolved into a 7-subunits core complex with the XPB translocase and the XPD helicase, and the 3-subunits kinase complex CAK, which also exists as a free complex with a distinct function. Initially identified as basal transcription factor, TFIIH also participates in transcription regulation and plays a key role in nucleotide excision repair (NER) for opening DNA at damaged sites, lesion verification and recruitment of additional repair factors. Our understanding of TFIIH function in eukaryotic cells has greatly benefited from studies of the genetic rare diseases xeroderma pigmentosum (XP), Cockayne syndrome (CS) and trichothiodystrophy (TTD), that are not only characterized by cancer and aging predispositions but also by neurological and developmental defects. Although much remains unknown about TFIIH function, significant progresses have been done regarding the structure of the complex, the functions of its catalytic subunits and the multiple roles of the regulatory core-TFIIH subunits. This review provides a non-exhaustive survey of key discoveries on the structure and function of this pivotal factor, which can be considered as a promising target for therapeutic strategies.
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Affiliation(s)
- Olga Kolesnikova
- Institut de Génétique et de Biologie Moléculaire et Cellulaire Illkirch Cedex, C.U. Strasbourg, France; Centre National de la Recherche Scientifique, UMR7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Laura Radu
- Institut de Génétique et de Biologie Moléculaire et Cellulaire Illkirch Cedex, C.U. Strasbourg, France; Centre National de la Recherche Scientifique, UMR7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Arnaud Poterszman
- Institut de Génétique et de Biologie Moléculaire et Cellulaire Illkirch Cedex, C.U. Strasbourg, France; Centre National de la Recherche Scientifique, UMR7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U1258, Illkirch, France; Université de Strasbourg, Illkirch, France.
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54
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Seoane M, Buhs S, Iglesias P, Strauss J, Puller AC, Müller J, Gerull H, Feldhaus S, Alawi M, Brandner JM, Eggert D, Du J, Thomale J, Wild PJ, Zimmermann M, Sternsdorf T, Schumacher U, Nollau P, Fisher DE, Horstmann MA. Lineage-specific control of TFIIH by MITF determines transcriptional homeostasis and DNA repair. Oncogene 2019; 38:3616-3635. [PMID: 30651597 PMCID: PMC6756118 DOI: 10.1038/s41388-018-0661-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 12/05/2018] [Indexed: 11/15/2022]
Abstract
The melanocytic lineage, which is prominently exposed to ultraviolet radiation (UVR) and radiation-independent oxidative damage, requires specific DNA-damage response mechanisms to maintain genomic and transcriptional homeostasis. The coordinate lineage-specific regulation of intricately intertwined DNA repair and transcription is incompletely understood. Here we demonstrate that the Microphthalmia-associated transcription factor (MITF) directly controls general transcription and UVR-induced nucleotide excision repair by transactivation of GTF2H1 as a core element of TFIIH. Thus, MITF ensures the rapid resumption of transcription after completion of strand repair and maintains transcriptional output, which is indispensable for survival of the melanocytic lineage including melanoma in vitro and in vivo. Moreover, MITF controls c-MYC implicated in general transcription by transactivation of far upstream binding protein 2 (FUBP2/KSHRP), which induces c-MYC pulse regulation through TFIIH, and experimental depletion of MITF results in consecutive loss of CDK7 in the TFIIH-CAK subcomplex. Targeted for proteasomal degradation, CDK7 is dependent on transactivation by MITF or c-MYC to maintain a steady state. The dependence of TFIIH-CAK on sequence-specific MITF and c-MYC constitutes a previously unrecognized mechanism feeding into super-enhancer-driven or other oncogenic transcriptional circuitries, which supports the concept of a transcription-directed therapeutic intervention in melanoma.
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Affiliation(s)
- Marcos Seoane
- Research Institute Children's Cancer Center Hamburg, Hamburg, 20246, Germany.,Department of Pediatric Hematology and Oncology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - Sophia Buhs
- Research Institute Children's Cancer Center Hamburg, Hamburg, 20246, Germany.,Department of Pediatric Hematology and Oncology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - Pablo Iglesias
- Research Institute Children's Cancer Center Hamburg, Hamburg, 20246, Germany.,Department of Pediatric Hematology and Oncology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - Julia Strauss
- Research Institute Children's Cancer Center Hamburg, Hamburg, 20246, Germany.,Department of Pediatric Hematology and Oncology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - Ann-Christin Puller
- Research Institute Children's Cancer Center Hamburg, Hamburg, 20246, Germany.,Department of Pediatric Hematology and Oncology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - Jürgen Müller
- Research Institute Children's Cancer Center Hamburg, Hamburg, 20246, Germany.,Department of Pediatric Hematology and Oncology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - Helwe Gerull
- Research Institute Children's Cancer Center Hamburg, Hamburg, 20246, Germany.,Department of Pediatric Hematology and Oncology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - Susanne Feldhaus
- Institute of Anatomy and Experimental Morphology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - Malik Alawi
- Bioinformatics Service Facility, University Medical Center Hamburg, Hamburg, 20246, Germany.,Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, 20251, Germany
| | - Johanna M Brandner
- Department of Dermatology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - Dennis Eggert
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, 20251, Germany.,Max-Planck-Institute for the Structure and Dynamics of Matter, Hamburg, 22761, Germany
| | - Jinyan Du
- Department of Pediatric Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, MA, 02115, USA.,Merrimack Pharmaceuticals, Cambridge, MA, 02139, USA
| | - Jürgen Thomale
- Institute of Cell Biology, University Duisburg-Essen, Essen, 45122, Germany
| | - Peter J Wild
- Institute of Surgical Pathology, University Hospital Zürich, Zürich, 8091, Switzerland
| | - Martin Zimmermann
- Department of Pediatric Hematology and Oncology, Medical School Hannover, Hannover, 30625, Germany
| | - Thomas Sternsdorf
- Research Institute Children's Cancer Center Hamburg, Hamburg, 20246, Germany.,Department of Pediatric Hematology and Oncology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - Udo Schumacher
- Institute of Anatomy and Experimental Morphology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - Peter Nollau
- Research Institute Children's Cancer Center Hamburg, Hamburg, 20246, Germany.,Department of Pediatric Hematology and Oncology, University Medical Center Hamburg, Hamburg, 20246, Germany
| | - David E Fisher
- Department of Dermatology, Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Martin A Horstmann
- Research Institute Children's Cancer Center Hamburg, Hamburg, 20246, Germany. .,Department of Pediatric Hematology and Oncology, University Medical Center Hamburg, Hamburg, 20246, Germany.
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55
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Abstract
The fact that many cancer types display transcriptional addiction driven by dysregulation of oncogenic enhancers and transcription factors has led to increased interest in a group of protein kinases, known as transcriptional cyclin dependent kinases (tCDKs), as potential therapeutic targets. Despite early reservations about targeting a process that is essential to healthy cell types, there is now evidence that targeting tCDKs could provide enough therapeutic window to be effective in the clinic. Here, we discuss recent developments in this field, with an emphasis on highly-selective inhibitors and the challenges to be addressed before these inhibitors could be used for therapeutic purposes. Abbreviations: CAK: CDK-activating kinase;CDK: cyclin-dependent kinase;CMGC group: CDK-, MAPK-, GSK3-, and CLK-like;CTD: C-terminal repeat domain of the RPB1 subunit of RNA polymerase II;DRB: 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole;mCRPC: metastatic castration-resistant prostate cancer;NSCLC: non-small cell lung cancer;P-TEFb: positive elongation factor b;RNAPII: RNA polymerase II;S2: serine-2 of CTD repeats;S5: serine-5 of CTD repeats;S7: serine-7 of CTD repeats;SEC: super elongation complex;tCDK: transcriptional cyclin-dependent kinase;TNBC: triple-negative breast cancer
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Affiliation(s)
- Matthew D Galbraith
- a Linda Crnic Institute for Down Syndrome, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA.,b Department of Pharmacology, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA
| | - Heather Bender
- a Linda Crnic Institute for Down Syndrome, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA.,b Department of Pharmacology, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA
| | - Joaquín M Espinosa
- a Linda Crnic Institute for Down Syndrome, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA.,b Department of Pharmacology, School of Medicine , University of Colorado Anschutz Medical Campus , Aurora , CO , USA.,c Department of Molecular, Cellular and Developmental Biology , University of Colorado Boulder , Boulder , CO , USA
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56
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Patel H, Periyasamy M, Sava GP, Bondke A, Slafer BW, Kroll SHB, Barbazanges M, Starkey R, Ottaviani S, Harrod A, Aboagye EO, Buluwela L, Fuchter MJ, Barrett AGM, Coombes RC, Ali S. ICEC0942, an Orally Bioavailable Selective Inhibitor of CDK7 for Cancer Treatment. Mol Cancer Ther 2018; 17:1156-1166. [PMID: 29545334 PMCID: PMC5985928 DOI: 10.1158/1535-7163.mct-16-0847] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 12/22/2017] [Accepted: 03/06/2018] [Indexed: 12/31/2022]
Abstract
Recent reports indicate that some cancer types are especially sensitive to transcription inhibition, suggesting that targeting the transcriptional machinery provides new approaches to cancer treatment. Cyclin-dependent kinase (CDK)7 is necessary for transcription, and acts by phosphorylating the C-terminal domain (CTD) of RNA polymerase II (PolII) to enable transcription initiation. CDK7 additionally regulates the activities of a number of transcription factors, including estrogen receptor (ER)-α. Here we describe a new, orally bioavailable CDK7 inhibitor, ICEC0942. It selectively inhibits CDK7, with an IC50 of 40 nmol/L; IC50 values for CDK1, CDK2, CDK5, and CDK9 were 45-, 15-, 230-, and 30-fold higher. In vitro studies show that a wide range of cancer types are sensitive to CDK7 inhibition with GI50 values ranging between 0.2 and 0.3 μmol/L. In xenografts of both breast and colorectal cancers, the drug has substantial antitumor effects. In addition, combination therapy with tamoxifen showed complete growth arrest of ER-positive tumor xenografts. Our findings reveal that CDK7 inhibition provides a new approach, especially for ER-positive breast cancer and identify ICEC0942 as a prototype drug with potential utility as a single agent or in combination with hormone therapies for breast cancer. ICEC0942 may also be effective in other cancers that display characteristics of transcription factor addiction, such as acute leukaemia and small-cell lung cancer. Mol Cancer Ther; 17(6); 1156-66. ©2018 AACR.
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Affiliation(s)
- Hetal Patel
- Division of Cancer, Department of Surgery & Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Manikandan Periyasamy
- Division of Cancer, Department of Surgery & Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Georgina P Sava
- Division of Cancer, Department of Surgery & Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Alexander Bondke
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Brian W Slafer
- Department of Chemistry, Imperial College London, London, United Kingdom
| | | | - Marion Barbazanges
- Department of Chemistry, Imperial College London, London, United Kingdom
| | - Richard Starkey
- Division of Cancer, Department of Surgery & Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Silvia Ottaviani
- Division of Cancer, Department of Surgery & Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Alison Harrod
- Division of Cancer, Department of Surgery & Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Eric O Aboagye
- Comprehensive Cancer Imaging Centre, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Laki Buluwela
- Division of Cancer, Department of Surgery & Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Matthew J Fuchter
- Department of Chemistry, Imperial College London, London, United Kingdom
| | | | - R Charles Coombes
- Division of Cancer, Department of Surgery & Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom.
| | - Simak Ali
- Division of Cancer, Department of Surgery & Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom.
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57
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Rimel JK, Taatjes DJ. The essential and multifunctional TFIIH complex. Protein Sci 2018; 27:1018-1037. [PMID: 29664212 PMCID: PMC5980561 DOI: 10.1002/pro.3424] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 12/19/2022]
Abstract
TFIIH is a 10‐subunit complex that regulates RNA polymerase II (pol II) transcription but also serves other important biological roles. Although much remains unknown about TFIIH function in eukaryotic cells, much progress has been made even in just the past few years, due in part to technological advances (e.g. cryoEM and single molecule methods) and the development of chemical inhibitors of TFIIH enzymes. This review focuses on the major cellular roles for TFIIH, with an emphasis on TFIIH function as a regulator of pol II transcription. We describe the structure of TFIIH and its roles in pol II initiation, promoter‐proximal pausing, elongation, and termination. We also discuss cellular roles for TFIIH beyond transcription (e.g. DNA repair, cell cycle regulation) and summarize small molecule inhibitors of TFIIH and diseases associated with defects in TFIIH structure and function.
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Affiliation(s)
- Jenna K Rimel
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado, 80303
| | - Dylan J Taatjes
- Department of Chemistry & Biochemistry, University of Colorado, Boulder, Colorado, 80303
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58
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Krasinska L, Fisher D. Non-Cell Cycle Functions of the CDK Network in Ciliogenesis: Recycling the Cell Cycle Oscillator. Bioessays 2018; 40:e1800016. [DOI: 10.1002/bies.201800016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/22/2018] [Indexed: 01/05/2023]
Affiliation(s)
- Liliana Krasinska
- Institut de Génétique Moléculaire de Montpellier (IGMM); University of Montpellier, CNRS 1919 Route de Mende; Montpellier 34293 France
- Equipe Labellisée LIGUE 2018; Ligue Nationale contre le Cancer; 75013 Paris France
| | - Daniel Fisher
- Institut de Génétique Moléculaire de Montpellier (IGMM); University of Montpellier, CNRS 1919 Route de Mende; Montpellier 34293 France
- Equipe Labellisée LIGUE 2018; Ligue Nationale contre le Cancer; 75013 Paris France
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59
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Costa C, Santos M, Martínez-Fernández M, Lorz C, Lázaro S, Paramio JM. Deregulation of the pRb-E2F4 axis alters epidermal homeostasis and favors tumor development. Oncotarget 2018; 7:75712-75728. [PMID: 27708231 PMCID: PMC5342772 DOI: 10.18632/oncotarget.12362] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 09/19/2016] [Indexed: 11/25/2022] Open
Abstract
E2F/RB activity is altered in most human tumors. The retinoblastoma family of proteins plays a key role in regulating the progression of the cell cycle from the G1 to S phases. This is achieved through negative regulation of E2F transcription factors, important positive regulators of cell cycle entry. E2F family members are divided into two groups: activators (E2F1-E2F3a) and repressors (E2F3b-E2F8). E2F4 accounts for a large part of the E2F activity and is a main E2F repressor member in vivo. Perturbations in the balance from quiescence towards proliferation contribute to increased mitotic gene expression levels frequently observed in cancer. We have previously reported that combined Rb1-Rbl1 or Rb1-E2f1 ablation in epidermis produces important alterations in epidermal proliferation and differentiation, leading to tumor development. However, the possible roles of E2F4 in this context are still to be determined. Here, we show the absence of any discernible phenotype in the skin of mice lacking of E2f4. In contrast, the inducible loss of Rb1 in the epidermis of E2F4-null mice produced multiple skin abnormalities including altered differentiation and proliferation, spontaneous wounds, carcinoma in situ development and stem cell perturbations. All these phenotypic alterations are associated with extensive gene expression changes, the induction of c-myc and the Akt activation. Moreover the whole transcriptome analyses in comparison with previous models generated also revealed extensive changes in multiple repressive complexes and in transcription factor activity. These results point to E2F4 as a master regulator in multiple steps of epidermal homeostasis in Rb1 absence.
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Affiliation(s)
- Clotilde Costa
- Unidad de Oncología Molecular, CIEMAT (ed70A), 28040 Madrid, Spain.,Present address: Unidad Mixta Roche-Chus, Hospital Universitario, 15706 Santiago de Compostela, Spain
| | - Mirentxu Santos
- Unidad de Oncología Molecular, CIEMAT (ed70A), 28040 Madrid, Spain.,Unidad de Oncología Molecular y Celular, Instituto de Investigaciones Biomed, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
| | - Mónica Martínez-Fernández
- Unidad de Oncología Molecular, CIEMAT (ed70A), 28040 Madrid, Spain.,Unidad de Oncología Molecular y Celular, Instituto de Investigaciones Biomed, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
| | - Corina Lorz
- Unidad de Oncología Molecular, CIEMAT (ed70A), 28040 Madrid, Spain.,Unidad de Oncología Molecular y Celular, Instituto de Investigaciones Biomed, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
| | - Sara Lázaro
- Unidad de Oncología Molecular, CIEMAT (ed70A), 28040 Madrid, Spain
| | - Jesús M Paramio
- Unidad de Oncología Molecular, CIEMAT (ed70A), 28040 Madrid, Spain.,Unidad de Oncología Molecular y Celular, Instituto de Investigaciones Biomed, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain
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60
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Abdullah AI, Zhang H, Nie Y, Tang W, Sun T. CDK7 and miR-210 Co-regulate Cell-Cycle Progression of Neural Progenitors in the Developing Neocortex. Stem Cell Reports 2017; 7:69-79. [PMID: 27411104 PMCID: PMC4944761 DOI: 10.1016/j.stemcr.2016.06.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 06/08/2016] [Accepted: 06/09/2016] [Indexed: 11/17/2022] Open
Abstract
The molecular mechanisms regulating neural progenitor (NP) proliferation are fundamental in establishing the cytoarchitecture of the mammalian neocortex. The rate of cell-cycle progression and a fine-tuned balance between cell-cycle re-entry and exit determine the numbers of both NPs and neurons as well as postmitotic neuronal laminar distribution in the cortical wall. Here, we demonstrate that the microRNA (miRNA) miR-210 is required for normal mouse NP cell-cycle progression. Overexpression of miR-210 promotes premature cell-cycle exit and terminal differentiation in NPs, resulting in an increase in early-born postmitotic neurons. Conversely, miR-210 knockdown promotes an increase in the radial glial cell population and delayed differentiation, resulting in an increase in late-born postmitotic neurons. Moreover, the cyclin-dependent kinase CDK7 is regulated by miR-210 and is necessary for normal NP cell-cycle progression. Our findings demonstrate that miRNAs are essential for normal NP proliferation and cell-cycle progress during neocortical development. miR-210 level is essential for cell-cycle progression in cortical neural progenitors Cdk7 and miR-210 control neural progenitor proliferation miR-210 promotes premature cell-cycle exit and differentiation in neural progenitors miR-210 expression induces a deep-layer neuronal fate in the neocortex
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Affiliation(s)
- Aisha I Abdullah
- Department of Cell and Developmental Biology, Cornell University Weill Medical College, 1300 York Avenue, Box 60, New York, NY 10065, USA
| | - Haijun Zhang
- Department of Cell and Developmental Biology, Cornell University Weill Medical College, 1300 York Avenue, Box 60, New York, NY 10065, USA; Department of Genetic Medicine, Cornell University Weill Medical College, 1300 York Avenue, New York, NY 10065, USA
| | - Yanzhen Nie
- Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Wei Tang
- Shanghai Jiao Tong University School of Medicine, Ruijin Hospital, 197 2nd Ruijin Road, Shanghai 200025, China.
| | - Tao Sun
- Department of Cell and Developmental Biology, Cornell University Weill Medical College, 1300 York Avenue, Box 60, New York, NY 10065, USA.
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61
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Abstract
Over the past two decades there has been a great deal of interest in the development of inhibitors of the cyclin-dependent kinases (CDKs). This attention initially stemmed from observations that different CDK isoforms have key roles in cancer cell proliferation through loss of regulation of the cell cycle, a hallmark feature of cancer. CDKs have now been shown to regulate other processes, particularly various aspects of transcription. The early non-selective CDK inhibitors exhibited considerable toxicity and proved to be insufficiently active in most cancers. The lack of patient selection biomarkers and an absence of understanding of the inhibitory profile required for efficacy hampered the development of these inhibitors. However, the advent of potent isoform-selective inhibitors with accompanying biomarkers has re-ignited interest. Palbociclib, a selective CDK4/6 inhibitor, is now approved for the treatment of ER+/HER2- advanced breast cancer. Current developments in the field include the identification of potent and selective inhibitors of the transcriptional CDKs; these include tool compounds that have allowed exploration of individual CDKs as cancer targets and the determination of their potential therapeutic windows. Biomarkers that allow the selection of patients likely to respond are now being discovered. Drug resistance has emerged as a major hurdle in the clinic for most protein kinase inhibitors and resistance mechanism are beginning to be identified for CDK inhibitors. This suggests that the selective inhibitors may be best used combined with standard of care or other molecularly targeted agents now in development rather than in isolation as monotherapies.
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Affiliation(s)
- Steven R Whittaker
- Division of Cancer Therapeutics, The Institute of Cancer Research, London SW7 3RP, United Kingdom
| | - Aurélie Mallinger
- Division of Cancer Therapeutics, The Institute of Cancer Research, London SW7 3RP, United Kingdom; Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London SW7 3RP, United Kingdom
| | - Paul Workman
- Division of Cancer Therapeutics, The Institute of Cancer Research, London SW7 3RP, United Kingdom; Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London SW7 3RP, United Kingdom
| | - Paul A Clarke
- Division of Cancer Therapeutics, The Institute of Cancer Research, London SW7 3RP, United Kingdom; Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London SW7 3RP, United Kingdom.
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JNKs function as CDK4-activating kinases by phosphorylating CDK4 and p21. Oncogene 2017; 36:4349-4361. [PMID: 28368408 PMCID: PMC5537611 DOI: 10.1038/onc.2017.7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 12/16/2016] [Accepted: 01/11/2017] [Indexed: 12/12/2022]
Abstract
Cyclin D-CDK4/6 are the first cyclin-dependent kinase (CDK) complexes to be activated by mitogenic/oncogenic pathways. They have a central role in the cell multiplication decision and in its deregulation in cancer cells. We identified T172 phosphorylation of CDK4 rather than cyclin D accumulation as the distinctly regulated step determining CDK4 activation. This finding challenges the view that the only identified metazoan CDK-activating kinase, cyclin H-CDK7-Mat1 (CAK), which is constitutively active, is responsible for the activating phosphorylation of all cell cycle CDKs. We previously showed that T172 phosphorylation of CDK4 is conditioned by an adjacent proline (P173), which is not present in CDK6 and CDK1/2. Although CDK7 activity was recently shown to be required for CDK4 activation, we proposed that proline-directed kinases might specifically initiate the activation of CDK4. Here, we report that JNKs, but not ERK1/2 or CAK, can be direct CDK4-activating kinases for cyclin D-CDK4 complexes that are inactivated by p21-mediated stabilization. JNKs and ERK1/2 also phosphorylated p21 at S130 and T57, which might facilitate CDK7-dependent activation of p21-bound CDK4, however, mutation of these sites did not impair the phosphorylation of CDK4 by JNKs. In two selected tumor cells, two different JNK inhibitors inhibited the phosphorylation and activation of cyclin D1-CDK4-p21 but not the activation of cyclin D3-CDK4 that is mainly associated to p27. Specific inhibition by chemical genetics in MEFs confirmed the involvement of JNK2 in cyclin D1-CDK4 activation. Therefore, JNKs could be activating kinases for cyclin D1-CDK4 bound to p21, by independently phosphorylating both CDK4 and p21.
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63
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Hazel P, Kroll SHB, Bondke A, Barbazanges M, Patel H, Fuchter MJ, Coombes RC, Ali S, Barrett AGM, Freemont PS. Inhibitor Selectivity for Cyclin-Dependent Kinase 7: A Structural, Thermodynamic, and Modelling Study. ChemMedChem 2017; 12:372-380. [PMID: 28125165 DOI: 10.1002/cmdc.201600535] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/25/2017] [Indexed: 01/24/2023]
Abstract
Deregulation of the cell cycle by mechanisms that lead to elevated activities of cyclin-dependent kinases (CDK) is a feature of many human diseases, cancer in particular. We identified small-molecule inhibitors that selectively inhibit CDK7, the kinase that phosphorylates cell-cycle CDKs to promote their activities. To investigate the selectivity of these inhibitors we used a combination of structural, biophysical, and modelling approaches. We determined the crystal structures of the CDK7-selective compounds ICEC0942 and ICEC0943 bound to CDK2, and used these to build models of inhibitor binding to CDK7. Molecular dynamics (MD) simulations of inhibitors bound to CDK2 and CDK7 generated possible models of inhibitor binding. To experimentally validate these models, we gathered isothermal titration calorimetry (ITC) binding data for recombinant wild-type and binding site mutants of CDK7 and CDK2. We identified specific residues of CDK7, notably Asp155, that are involved in determining inhibitor selectivity. Our MD simulations also show that the flexibility of the G-rich and activation loops of CDK7 is likely an important determinant of inhibitor specificity similar to CDK2.
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Affiliation(s)
- Pascale Hazel
- Section of Structural Biology, Department of Medicine, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Sebastian H B Kroll
- Department of Chemistry, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Alexander Bondke
- Department of Chemistry, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Marion Barbazanges
- Department of Chemistry, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Hetal Patel
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK
| | - Matthew J Fuchter
- Department of Chemistry, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - R Charles Coombes
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK
| | - Simak Ali
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK
| | - Anthony G M Barrett
- Department of Chemistry, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Paul S Freemont
- Section of Structural Biology, Department of Medicine, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
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Brier ASB, Loft A, Madsen J, Rosengren T, Nielsen R, Schmidt SF, Liu Z, Yan Q, Gronemeyer H, Mandrup S. The KDM5 family is required for activation of pro-proliferative cell cycle genes during adipocyte differentiation. Nucleic Acids Res 2017; 45:1743-1759. [PMID: 27899593 PMCID: PMC5389521 DOI: 10.1093/nar/gkw1156] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 11/01/2016] [Accepted: 11/05/2016] [Indexed: 12/23/2022] Open
Abstract
The KDM5 family of histone demethylases removes the H3K4 tri-methylation (H3K4me3) mark frequently found at promoter regions of actively transcribed genes and is therefore generally considered to contribute to corepression. In this study, we show that knockdown (KD) of all expressed members of the KDM5 family in white and brown preadipocytes leads to deregulated gene expression and blocks differentiation to mature adipocytes. KDM5 KD leads to a considerable increase in H3K4me3 at promoter regions; however, these changes in H3K4me3 have a limited effect on gene expression per se. By contrast, genome-wide analyses demonstrate that KDM5A is strongly enriched at KDM5-activated promoters, which generally have high levels of H3K4me3 and are associated with highly expressed genes. We show that KDM5-activated genes include a large set of cell cycle regulators and that the KDM5s are necessary for mitotic clonal expansion in 3T3-L1 cells, indicating that KDM5 KD may interfere with differentiation in part by impairing proliferation. Notably, the demethylase activity of KDM5A is required for activation of at least a subset of pro-proliferative cell cycle genes. In conclusion, the KDM5 family acts as dual modulators of gene expression in preadipocytes and is required for early stage differentiation and activation of pro-proliferative cell cycle genes.
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Affiliation(s)
- Ann-Sofie B. Brier
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Anne Loft
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Jesper G. S. Madsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
- The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Thomas Rosengren
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Ronni Nielsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Søren F. Schmidt
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
| | - Zongzhi Liu
- Department of Pathology, Yale School of Medicine, New Haven, CT, USA
| | - Qin Yan
- Department of Pathology, Yale School of Medicine, New Haven, CT, USA
| | - Hinrich Gronemeyer
- Equipe Labellisée Ligue Contre le Cancer, Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, UMR7104, Institut National de la Santé et de la Recherche Médicale, U964, Université de Strasbourg, Illkirch, France
| | - Susanne Mandrup
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, 5230 Odense M, Denmark
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Clarke PA, Ortiz-Ruiz MJ, TePoele R, Adeniji-Popoola O, Box G, Court W, Czasch S, El Bawab S, Esdar C, Ewan K, Gowan S, De Haven Brandon A, Hewitt P, Hobbs SM, Kaufmann W, Mallinger A, Raynaud F, Roe T, Rohdich F, Schiemann K, Simon S, Schneider R, Valenti M, Weigt S, Blagg J, Blaukat A, Dale TC, Eccles SA, Hecht S, Urbahns K, Workman P, Wienke D. Assessing the mechanism and therapeutic potential of modulators of the human Mediator complex-associated protein kinases. eLife 2016; 5:e20722. [PMID: 27935476 PMCID: PMC5224920 DOI: 10.7554/elife.20722] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 11/29/2016] [Indexed: 12/11/2022] Open
Abstract
Mediator-associated kinases CDK8/19 are context-dependent drivers or suppressors of tumorigenesis. Their inhibition is predicted to have pleiotropic effects, but it is unclear whether this will impact on the clinical utility of CDK8/19 inhibitors. We discovered two series of potent chemical probes with high selectivity for CDK8/19. Despite pharmacodynamic evidence for robust on-target activity, the compounds exhibited modest, though significant, efficacy against human tumor lines and patient-derived xenografts. Altered gene expression was consistent with CDK8/19 inhibition, including profiles associated with super-enhancers, immune and inflammatory responses and stem cell function. In a mouse model expressing oncogenic beta-catenin, treatment shifted cells within hyperplastic intestinal crypts from a stem cell to a transit amplifying phenotype. In two species, neither probe was tolerated at therapeutically-relevant exposures. The complex nature of the toxicity observed with two structurally-differentiated chemical series is consistent with on-target effects posing significant challenges to the clinical development of CDK8/19 inhibitors.
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Affiliation(s)
- Paul A Clarke
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | - Maria-Jesus Ortiz-Ruiz
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | - Robert TePoele
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | - Olajumoke Adeniji-Popoola
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | - Gary Box
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | - Will Court
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | | | | | | | - Ken Ewan
- School of Bioscience, Cardiff University, Cardiff, United Kingdom
| | - Sharon Gowan
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | - Alexis De Haven Brandon
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | | | - Stephen M Hobbs
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | | | - Aurélie Mallinger
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | - Florence Raynaud
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | - Toby Roe
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | | | | | | | | | - Melanie Valenti
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | | | - Julian Blagg
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | | | - Trevor C Dale
- School of Bioscience, Cardiff University, Cardiff, United Kingdom
| | - Suzanne A Eccles
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
| | | | | | - Paul Workman
- Cancer Research UK Cancer Therapeutics Unit, The Institute of Cancer Research, London, United Kingdom
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Wang H, Jo YJ, Sun TY, Namgoong S, Cui XS, Oh JS, Kim NH. Inhibition of CDK7 bypasses spindle assembly checkpoint via premature cyclin B degradation during oocyte meiosis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2993-3000. [DOI: 10.1016/j.bbamcr.2016.09.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 09/21/2016] [Accepted: 09/25/2016] [Indexed: 01/10/2023]
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Patel H, Abduljabbar R, Lai CF, Periyasamy M, Harrod A, Gemma C, Steel JH, Patel N, Busonero C, Jerjees D, Remenyi J, Smith S, Gomm JJ, Magnani L, Győrffy B, Jones LJ, Fuller-Pace F, Shousha S, Buluwela L, Rakha EA, Ellis IO, Coombes RC, Ali S. Expression of CDK7, Cyclin H, and MAT1 Is Elevated in Breast Cancer and Is Prognostic in Estrogen Receptor-Positive Breast Cancer. Clin Cancer Res 2016; 22:5929-5938. [PMID: 27301701 PMCID: PMC5293170 DOI: 10.1158/1078-0432.ccr-15-1104] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 04/22/2016] [Accepted: 05/23/2016] [Indexed: 01/16/2023]
Abstract
PURPOSE CDK-activating kinase (CAK) is required for the regulation of the cell cycle and is a trimeric complex consisting of cyclin-dependent kinase 7 (CDK7), Cyclin H, and the accessory protein, MAT1. CDK7 also plays a critical role in regulating transcription, primarily by phosphorylating RNA polymerase II, as well as transcription factors such as estrogen receptor-α (ER). Deregulation of cell cycle and transcriptional control are general features of tumor cells, highlighting the potential for the use of CDK7 inhibitors as novel cancer therapeutics. EXPERIMENTAL DESIGN mRNA and protein expression of CDK7 and its essential cofactors cyclin H and MAT1 were evaluated in breast cancer samples to determine if their levels are altered in cancer. Immunohistochemical staining of >900 breast cancers was used to determine the association with clinicopathologic features and patient outcome. RESULTS We show that expressions of CDK7, cyclin H, and MAT1 are all closely linked at the mRNA and protein level, and their expression is elevated in breast cancer compared with the normal breast tissue. Intriguingly, CDK7 expression was inversely proportional to tumor grade and size, and outcome analysis showed an association between CAK levels and better outcome. Moreover, CDK7 expression was positively associated with ER expression and in particular with phosphorylation of ER at serine 118, a site important for ER transcriptional activity. CONCLUSIONS Expressions of components of the CAK complex, CDK7, MAT1, and Cyclin H are elevated in breast cancer and correlate with ER. Like ER, CDK7 expression is inversely proportional to poor prognostic factors and survival. Clin Cancer Res; 22(23); 5929-38. ©2016 AACR.
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Affiliation(s)
- Hetal Patel
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Rezvan Abduljabbar
- Department of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Chun-Fui Lai
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Manikandan Periyasamy
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Alison Harrod
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Carolina Gemma
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Jennifer H Steel
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Naina Patel
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Claudia Busonero
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Dena Jerjees
- Department of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Judit Remenyi
- Division of Cancer Research, University of Dundee, Ninewells Hospital and Medical School, Dundee, United Kingdom
| | - Sally Smith
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London, United Kingdom
| | - Jennifer J Gomm
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London, United Kingdom
| | - Luca Magnani
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Balázs Győrffy
- MTA TTK Lendület Cancer Biomarker Research Group, Budapest, Hungary
- 2nd Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - Louise J Jones
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, John Vane Science Centre, Charterhouse Square, London, United Kingdom
| | - Frances Fuller-Pace
- Division of Cancer Research, University of Dundee, Ninewells Hospital and Medical School, Dundee, United Kingdom
| | - Sami Shousha
- Department of Histopathology, Charing Cross Hospital, Imperial College London, United Kingdom
| | - Laki Buluwela
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Emad A Rakha
- Department of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Ian O Ellis
- Department of Cancer and Stem Cells, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - R Charles Coombes
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Simak Ali
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom.
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Jiang Y, Lee J, Lee JH, Lee JW, Kim JH, Choi WH, Yoo YD, Cha-Molstad H, Kim BY, Kwon YT, Noh SA, Kim KP, Lee MJ. The arginylation branch of the N-end rule pathway positively regulates cellular autophagic flux and clearance of proteotoxic proteins. Autophagy 2016; 12:2197-2212. [PMID: 27560450 DOI: 10.1080/15548627.2016.1222991] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The N-terminal amino acid of a protein is an essential determinant of ubiquitination and subsequent proteasomal degradation in the N-end rule pathway. Using para-chloroamphetamine (PCA), a specific inhibitor of the arginylation branch of the pathway (Arg/N-end rule pathway), we identified that blocking the Arg/N-end rule pathway significantly impaired the fusion of autophagosomes with lysosomes. Under ER stress, ATE1-encoded Arg-tRNA-protein transferases carry out the N-terminal arginylation of the ER heat shock protein HSPA5 that initially targets cargo proteins, along with SQSTM1, to the autophagosome. At the late stage of autophagy, however, proteasomal degradation of arginylated HSPA5 might function as a critical checkpoint for the proper progression of autophagic flux in the cells. Consistently, the inhibition of the Arg/N-end rule pathway with PCA significantly elevated levels of MAPT and huntingtin aggregates, accompanied by increased numbers of LC3 and SQSTM1 puncta. Cells treated with the Arg/N-end rule inhibitor became more sensitized to proteotoxic stress-induced cytotoxicity. SILAC-based quantitative proteomics also revealed that PCA significantly alters various biological pathways, including cellular responses to stress, nutrient, and DNA damage, which are also closely involved in modulation of autophagic responses. Thus, our results indicate that the Arg/N-end rule pathway may function to actively protect cells from detrimental effects of cellular stresses, including proteotoxic protein accumulation, by positively regulating autophagic flux.
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Affiliation(s)
- Yanxialei Jiang
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea
| | - Jeeyoung Lee
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea.,b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Jung Hoon Lee
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea.,b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Joon Won Lee
- d Department of Applied Chemistry , College of Applied Sciences, Kyung Hee University , Yongin , Korea
| | - Ji Hyeon Kim
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea.,b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Won Hoon Choi
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea.,b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Young Dong Yoo
- b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Hyunjoo Cha-Molstad
- c World Class Institute, Korea Research Institute of Bioscience and Biotechnology , Ochang, Cheongwon , Korea
| | - Bo Yeon Kim
- c World Class Institute, Korea Research Institute of Bioscience and Biotechnology , Ochang, Cheongwon , Korea
| | - Yong Tae Kwon
- b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
| | - Sue Ah Noh
- d Department of Applied Chemistry , College of Applied Sciences, Kyung Hee University , Yongin , Korea
| | - Kwang Pyo Kim
- d Department of Applied Chemistry , College of Applied Sciences, Kyung Hee University , Yongin , Korea
| | - Min Jae Lee
- a Department of Biochemistry and Molecular Biology , Seoul National University College of Medicine , Seoul , Korea.,b Department of Biomedical Sciences , Seoul National University Graduate School , Seoul , Korea
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Abstract
The preimplantation development stage of mammalian embryogenesis consists of a series of highly conserved, regulated, and predictable cell divisions. This process is essential to allow the rapid expansion and differentiation of a single-cell zygote into a multicellular blastocyst containing cells of multiple developmental lineages. This period of development, also known as the germinal stage, encompasses several important developmental transitions, which are accompanied by dramatic changes in cell cycle profiles and dynamics. These changes are driven primarily by differences in the establishment and enforcement of cell cycle checkpoints, which must be bypassed to facilitate the completion of essential cell cycle events. Much of the current knowledge in this area has been amassed through the study of knockout models in mice. These mouse models are powerful experimental tools, which have allowed us to dissect the relative dependence of the early embryonic cell cycles on various aspects of the cell cycle machinery and highlight the extent of functional redundancy between members of the same gene family. This chapter will explore the ways in which the cell cycle machinery, their accessory proteins, and their stimuli operate during mammalian preimplantation using mouse models as a reference and how this allows for the usually well-defined stages of the cell cycle to be shaped and transformed during this unique and critical stage of development.
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Compe E, Egly JM. Nucleotide Excision Repair and Transcriptional Regulation: TFIIH and Beyond. Annu Rev Biochem 2016; 85:265-90. [DOI: 10.1146/annurev-biochem-060815-014857] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Emmanuel Compe
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale/Université de Strasbourg, 67404 Illkirch Cedex, Commune Urbaine Strasbourg, France; ,
| | - Jean-Marc Egly
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale/Université de Strasbourg, 67404 Illkirch Cedex, Commune Urbaine Strasbourg, France; ,
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71
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Chlamydas S, Holz H, Samata M, Chelmicki T, Georgiev P, Pelechano V, Dündar F, Dasmeh P, Mittler G, Cadete FT, Ramírez F, Conrad T, Wei W, Raja S, Manke T, Luscombe NM, Steinmetz LM, Akhtar A. Functional interplay between MSL1 and CDK7 controls RNA polymerase II Ser5 phosphorylation. Nat Struct Mol Biol 2016; 23:580-9. [PMID: 27183194 DOI: 10.1038/nsmb.3233] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 04/21/2016] [Indexed: 01/09/2023]
Abstract
Proper gene expression requires coordinated interplay among transcriptional coactivators, transcription factors and the general transcription machinery. We report here that MSL1, a central component of the dosage compensation complex in Drosophila melanogaster and Drosophila virilis, displays evolutionarily conserved sex-independent binding to promoters. Genetic and biochemical analyses reveal a functional interaction of MSL1 with CDK7, a subunit of the Cdk-activating kinase (CAK) complex of the general transcription factor TFIIH. Importantly, MSL1 depletion leads to decreased phosphorylation of Ser5 of RNA polymerase II. In addition, we demonstrate that MSL1 is a phosphoprotein, and transgenic flies expressing MSL1 phosphomutants show mislocalization of the histone acetyltransferase MOF and histone H4 K16 acetylation, thus ultimately causing male lethality due to a failure of dosage compensation. We propose that, by virtue of its interaction with components of the general transcription machinery, MSL1 exists in different phosphorylation states, thereby modulating transcription in flies.
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Affiliation(s)
- Sarantis Chlamydas
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Herbert Holz
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Maria Samata
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
- University of Freiburg, Faculty of Biology, Freiburg im Breisgau, Germany
| | - Tomasz Chelmicki
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Plamen Georgiev
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Vicent Pelechano
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Friederike Dündar
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
- University of Freiburg, Faculty of Biology, Freiburg im Breisgau, Germany
| | - Pouria Dasmeh
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Gerhard Mittler
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | | | - Fidel Ramírez
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Thomas Conrad
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Wu Wei
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
| | - Sunil Raja
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Thomas Manke
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
| | - Nicholas M Luscombe
- The Francis Crick Institute, London, UK
- UCL Genetics Institute, Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Lars M Steinmetz
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
| | - Asifa Akhtar
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg im Breisgau, Germany
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Bendris N, Lemmers B, Blanchard JM. Cell cycle, cytoskeleton dynamics and beyond: the many functions of cyclins and CDK inhibitors. Cell Cycle 2016; 14:1786-98. [PMID: 25789852 DOI: 10.1080/15384101.2014.998085] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
While targeting experiments carried out on the genes encoding many cell cycle regulators have challenged our views of cell cycle control, they also suggest that redundancy might not be the only explanation for the observed perplexing phenotypes. Indeed, several observations hint at functions of cyclins and CDK inhibitors that cannot be accounted for by their sole role as kinase regulators. They are found involved in many cellular transactions, depending or not on CDKs that are not directly linked to cell cycle control, but participating to general mechanisms such as transcription, DNA repair or cytoskeleton dynamics. In this review we discuss the roles that these alternative functions might have in cancer cell proliferation and migration that sometime even challenge their definition as proliferation markers.
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Affiliation(s)
- Nawal Bendris
- a Institut de Génétique Moléculaire de Montpellier; CNRS; Montpellier; France; Université Montpellier 2 ; Place Eugène Bataillon; Montpellier , France
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73
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Abstract
Ageing is the main risk factor for major non-communicable chronic lung diseases, including chronic obstructive pulmonary disease, most forms of lung cancer and idiopathic pulmonary fibrosis. While the prevalence of these diseases continually increases with age, their respective incidence peaks at different times during the lifespan, suggesting specific effects of ageing on the onset and/or pathogenesis of chronic obstructive pulmonary disease, lung cancer and idiopathic pulmonary fibrosis. Recently, the nine hallmarks of ageing have been defined as cell-autonomous and non-autonomous pathways involved in ageing. Here, we review the available evidence for the involvement of each of these hallmarks in the pathogenesis of chronic obstructive pulmonary disease, lung cancer, or idiopathic pulmonary fibrosis. Importantly, we propose an additional hallmark, “dysregulation of the extracellular matrix”, which we argue acts as a crucial modifier of cell-autonomous changes and functions, and as a key feature of the above-mentioned lung diseases.
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74
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A novel CDK7 inhibitor of the Pyrazolotriazine class exerts broad-spectrum antiviral activity at nanomolar concentrations. Antimicrob Agents Chemother 2015; 59:2062-71. [PMID: 25624324 DOI: 10.1128/aac.04534-14] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Protein kinases represent central and multifunctional regulators of a balanced virus-host interaction. Cyclin-dependent protein kinase 7 (CDK7) plays crucial regulatory roles in cell cycle and transcription, both connected with the replication of many viruses. Previously, we developed a CDK7 inhibitor, LDC4297, that inhibits CDK7 in vitro in the nano-picomolar range. Novel data from a kinome-wide evaluation (>330 kinases profiled in vitro) demonstrate a kinase selectivity. Importantly, we provide first evidence for the antiviral potential of the CDK7 inhibitor LDC4297, i.e., in exerting a block of the replication of human cytomegalovirus (HCMV) in primary human fibroblasts at nanomolar concentrations (50% effective concentration, 24.5 ± 1.3 nM). As a unique feature compared to approved antiherpesviral drugs, inhibition occurred already at the immediate-early level of HCMV gene expression. The mode of antiviral action was considered multifaceted since CDK7-regulated cellular factors that are supportive of HCMV replication were substantially affected by the inhibitors. An effect of LDC4297 was identified in the interference with HCMV-driven inactivation of retinoblastoma protein (Rb), a regulatory step generally considered a hallmark of herpesviral replication. In line with this finding, a broad inhibitory activity of the drug could be demonstrated against a selection of human and animal herpesviruses and adenoviruses, whereas other viruses only showed intermediate drug sensitivity. Summarized, the CDK7 inhibitor LDC4297 is a promising candidate for further antiviral drug development, possibly offering new options for a comprehensive approach to antiviral therapy.
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75
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Tagirov M, Rutkowska J. Sexual Dimorphism in the Early Embryogenesis in Zebra Finches. PLoS One 2014; 9:e114625. [PMID: 25493645 PMCID: PMC4262425 DOI: 10.1371/journal.pone.0114625] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 11/12/2014] [Indexed: 01/06/2023] Open
Abstract
Sex-specific gene expression before the onset of gonadogensis has been documented in embryos of mammals and chickens. In several mammalian species, differences in gene expression are accompanied by faster growth of pre-implantation male embryos. Here we asked whether avian embryos before gonadal differentiation are also sex-dimorphic in size and what genes regulate their growth. We used captive zebra finches (Taeniopygia guttata) whose freshly laid eggs were artificially incubated for 36–40 hours. Analyses controlling for the exact time of incubation of 81 embryos revealed that males were larger than females in terms of Hamburger and Hamilton stage and number of somites. Expression of 15 genes involved in cell cycle regulation, growth, metabolic activity, steroidogenic pathway and stress modulation were measured using RT-PCR in 5 male and 5 female embryos incubated for exactly 36 h. We found that in the presence of equal levels of the growth hormone itself, the faster growth of male embryos is most likely achieved by the overexpression of the growth hormone receptor gene and three other genes responsible for cell cycle regulation and metabolism, all of them located on the Z chromosome. Autosomal genes did not show sex-specific expression, except for the steroidogenic factor 1 which was expressed only in female embryos. To our knowledge this is the first report of sexual size dimorphism before gonadogenesis in birds. The finding suggests that faster growth of early male embryos is conserved through the mammalian and bird phyla, irrespective of their differential sex chromosome systems.
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Affiliation(s)
- Makhsud Tagirov
- Poultry Research Institute, Ukrainian Academy of Agrarian Sciences, Borky, Ukraine
| | - Joanna Rutkowska
- Institute of Environmental Sciences, Jagiellonian University, Kraków, Poland
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76
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Abstract
Cyclin-dependent kinases (CDKs) are involved in temporal control of the cell cycle and transcription and play central roles in cancer development and metastasis. Recently, Kwiatkowski and colleagues identified a novel CDK7-specific inhibitor, THZ1, that hinders proliferation in cancer cell lines and dampens global transcription in T cell leukemia.
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Affiliation(s)
- Kaixiang Cao
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA
| | - Ali Shilatifard
- Stowers Institute for Medical Research, 1000 East 50(th) Street, Kansas City, MO 64110, USA.
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77
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Cyclin-dependent kinase 7 controls mRNA synthesis by affecting stability of preinitiation complexes, leading to altered gene expression, cell cycle progression, and survival of tumor cells. Mol Cell Biol 2014; 34:3675-88. [PMID: 25047832 DOI: 10.1128/mcb.00595-14] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cyclin-dependent kinase 7 (CDK7) activates cell cycle CDKs and is a member of the general transcription factor TFIIH. Although there is substantial evidence for an active role of CDK7 in mRNA synthesis and associated processes, the degree of its influence on global and gene-specific transcription in mammalian species is unclear. In the current study, we utilize two novel inhibitors with high specificity for CDK7 to demonstrate a restricted but robust impact of CDK7 on gene transcription in vivo and in in vitro-reconstituted reactions. We distinguish between relative low- and high-dose responses and relate them to distinct molecular mechanisms and altered physiological responses. Low inhibitor doses cause rapid clearance of paused RNA polymerase II (RNAPII) molecules and sufficed to cause genome-wide alterations in gene expression, delays in cell cycle progression at both the G1/S and G2/M checkpoints, and diminished survival of human tumor cells. Higher doses and prolonged inhibition led to strong reductions in RNAPII carboxyl-terminal domain (CTD) phosphorylation, eventual activation of the p53 program, and increased cell death. Together, our data reason for a quantitative contribution of CDK7 to mRNA synthesis, which is critical for cellular homeostasis.
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78
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Corden JL. RNA polymerase II C-terminal domain: Tethering transcription to transcript and template. Chem Rev 2013; 113:8423-55. [PMID: 24040939 PMCID: PMC3988834 DOI: 10.1021/cr400158h] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jeffry L Corden
- Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine , 725 North Wolfe Street, Baltimore Maryland 21205, United States
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79
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Abstract
Cyclin-dependent kinases (Cdks) are serine/threonine kinases and their catalytic activities are modulated by interactions with cyclins and Cdk inhibitors (CKIs). Close cooperation between this trio is necessary for ensuring orderly progression through the cell cycle. In addition to their well-established function in cell cycle control, it is becoming increasingly apparent that mammalian Cdks, cyclins and CKIs play indispensable roles in processes such as transcription, epigenetic regulation, metabolism, stem cell self-renewal, neuronal functions and spermatogenesis. Even more remarkably, they can accomplish some of these tasks individually, without the need for Cdk/cyclin complex formation or kinase activity. In this Review, we discuss the latest revelations about Cdks, cyclins and CKIs with the goal of showcasing their functional diversity beyond cell cycle regulation and their impact on development and disease in mammals.
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Affiliation(s)
- Shuhui Lim
- Institute of Molecular and Cell Biology IMCB, A*STAR Agency for Science, Technology and Research, Singapore 138673, Republic of Singapore
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80
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Schachter MM, Fisher RP. The CDK-activating kinase Cdk7: taking yes for an answer. Cell Cycle 2013; 12:3239-40. [PMID: 24036541 PMCID: PMC3885630 DOI: 10.4161/cc.26355] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- Miriam Merzel Schachter
- Department of Structural and Chemical Biology; Graduate School of Biomedical Sciences; Icahn School of Medicine at Mount Sinai; New York, NY USA
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81
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Wu D, Gu QH, Li ZW. Cyclin-dependent kinases, control of cell cycle and hepatic fibrosis. Shijie Huaren Xiaohua Zazhi 2013; 21:2158-2163. [DOI: 10.11569/wcjd.v21.i22.2158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Multiple etiologies of liver disease lead to liver fibrosis by driving the activation of hepatic stellate cells (HSCs) into a myofibroblast-like phenotype that is contractile, proliferative and fibrogenic. Liver fibrosis is associated with the proliferation of HSCs, and the cell cycle of activated HSCs is abnormal. Cyclin-dependent kinases (CDKs) play essential roles in cell proliferation. However, the molecular mechanisms responsible for the abnormal proliferation of activated HSCs during hepatic fibrogenesis remain to be defined. Here we will review recent progress in understanding the associations among CDKs, the control of cell cycle and hepatic fibrosis, with an aim to reveal the potential mechanisms of hepatic fibrosis.
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82
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A Cdk7-Cdk4 T-loop phosphorylation cascade promotes G1 progression. Mol Cell 2013; 50:250-60. [PMID: 23622515 DOI: 10.1016/j.molcel.2013.04.003] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 02/20/2013] [Accepted: 04/01/2013] [Indexed: 01/13/2023]
Abstract
Eukaryotic cell division is controlled by cyclin-dependent kinases (CDKs), which require phosphorylation by a CDK-activating kinase (CAK) for full activity. Chemical genetics uncovered requirements for the metazoan CAK Cdk7 in determining cyclin specificity and activation order of Cdk2 and Cdk1 during S and G2 phases. It was unknown if Cdk7 also activates Cdk4 and Cdk6 to promote passage of the restriction (R) point, when continued cell-cycle progression becomes mitogen independent, or if CDK-activating phosphorylation regulates G1 progression. Here we show that Cdk7 is a Cdk4- and Cdk6-activating kinase in human cells, required to maintain activity, not just to establish the active state, as is the case for Cdk1 and Cdk2. Activating phosphorylation of Cdk7 rises concurrently with that of Cdk4 as cells exit quiescence and accelerates Cdk4 activation in vitro. Therefore, mitogen signaling drives a CDK-activation cascade during G1 progression, and CAK might be rate-limiting for R point passage.
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83
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Bisteau X, Paternot S, Colleoni B, Ecker K, Coulonval K, De Groote P, Declercq W, Hengst L, Roger PP. CDK4 T172 phosphorylation is central in a CDK7-dependent bidirectional CDK4/CDK2 interplay mediated by p21 phosphorylation at the restriction point. PLoS Genet 2013; 9:e1003546. [PMID: 23737759 PMCID: PMC3667761 DOI: 10.1371/journal.pgen.1003546] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 04/22/2013] [Indexed: 01/24/2023] Open
Abstract
Cell cycle progression, including genome duplication, is orchestrated by cyclin-dependent kinases (CDKs). CDK activation depends on phosphorylation of their T-loop by a CDK–activating kinase (CAK). In animals, the only known CAK for CDK2 and CDK1 is cyclin H-CDK7, which is constitutively active. Therefore, the critical activation step is dephosphorylation of inhibitory sites by Cdc25 phosphatases rather than unrestricted T-loop phosphorylation. Homologous CDK4 and CDK6 bound to cyclins D are master integrators of mitogenic/oncogenic signaling cascades by initiating the inactivation of the central oncosuppressor pRb and cell cycle commitment at the restriction point. Unlike the situation in CDK1 and CDK2 cyclin complexes, and in contrast to the weak but constitutive T177 phosphorylation of CDK6, we have identified the T-loop phosphorylation at T172 as the highly regulated step determining CDK4 activity. Whether both CDK4 and CDK6 phosphorylations are catalyzed by CDK7 remains unclear. To answer this question, we took a chemical-genetics approach by using analogue-sensitive CDK7(as/as) mutant HCT116 cells, in which CDK7 can be specifically inhibited by bulky adenine analogs. Intriguingly, CDK7 inhibition prevented activating phosphorylations of CDK4/6, but for CDK4 this was at least partly dependent on its binding to p21cip1. In response to CDK7 inhibition, p21-binding to CDK4 increased concomitantly with disappearance of the most abundant phosphorylation of p21, which we localized at S130 and found to be catalyzed by both CDK4 and CDK2. The S130A mutation of p21 prevented the activating CDK4 phosphorylation, and inhibition of CDK4/6 and CDK2 impaired phosphorylations of both p21 and p21-bound CDK4. Therefore, specific CDK7 inhibition revealed the following: a crucial but partly indirect CDK7 involvement in phosphorylation/activation of CDK4 and CDK6; existence of CDK4-activating kinase(s) other than CDK7; and novel CDK7-dependent positive feedbacks mediated by p21 phosphorylation by CDK4 and CDK2 to sustain CDK4 activation, pRb inactivation, and restriction point passage. In the cell cycle, duplication of all the cellular components and subsequent cell division are governed by a family of protein kinases associated with cyclins (CDKs). Related CDK4 and CDK6 bound to cyclins D are the first CDKs to be activated in response to cell proliferation signals. They thus play a central role in the cell multiplication decision, especially in most cancer cells in which CDK4 activity is highly deregulated. We have identified the activating T172 phosphorylation instead of cyclin D expression as the highly regulated step determining CDK4 activation. This finding contrasts with the prevalent view that the only identified metazoan CDK-activating kinase, CDK7, is constitutively active. By using human cells genetically engineered for specific chemical inhibition of CDK7, we found that CDK7 activity was indeed required for CDK4 activation. However, this dependence was conditioned by CDK4 binding to the CDK inhibitory protein p21, which increased in response to CDK7 inhibition. Further investigation revealed that CDK7 inhibition affects a major phosphorylation of p21, which we found to be required for CDK4 activation and performed by CDK4 itself and CDK2. Thus, depending on CDK7 activity, CDK4 and CDK2 facilitate CDK4 activation, generating novel positive feedbacks involved in the cell cycle decision.
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Affiliation(s)
- Xavier Bisteau
- WELBIO and Institute of Interdisciplinary Research (IRIBHM), Université Libre de Bruxelles, Brussels, Belgium
| | - Sabine Paternot
- WELBIO and Institute of Interdisciplinary Research (IRIBHM), Université Libre de Bruxelles, Brussels, Belgium
| | - Bianca Colleoni
- WELBIO and Institute of Interdisciplinary Research (IRIBHM), Université Libre de Bruxelles, Brussels, Belgium
| | - Karin Ecker
- Division of Medical Biochemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Katia Coulonval
- WELBIO and Institute of Interdisciplinary Research (IRIBHM), Université Libre de Bruxelles, Brussels, Belgium
| | - Philippe De Groote
- Department for Molecular Biomedical Research, VIB, and Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Wim Declercq
- Department for Molecular Biomedical Research, VIB, and Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Ludger Hengst
- Division of Medical Biochemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Pierre P. Roger
- WELBIO and Institute of Interdisciplinary Research (IRIBHM), Université Libre de Bruxelles, Brussels, Belgium
- * E-mail:
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84
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Abstract
Cyclin-dependent kinases (CDKs) play essential roles in cell proliferation and gene expression. Although distinct sets of CDKs work in cell division and transcription by RNA polymerase II (Pol II), they share a CDK-activating kinase (CAK), which is itself a CDK-Cdk7-in metazoans. Thus a unitary CDK network controls and may coordinate cycles of cell division and gene expression. Recent work reveals decisive roles for Cdk7 in both pathways. The CAK function of Cdk7 helps determine timing of activation and cyclin-binding preferences of different CDKs during the cell cycle. In the transcription cycle, Cdk7 is both an effector kinase, which phosphorylates Pol II and other proteins and helps establish promoter-proximal pausing; and a CAK for Cdk9 (P-TEFb), which releases Pol II from the pause. By governing the transition from initiation to elongation, Cdk7, Cdk9 and their substrates influence expression of genes important for developmental and cell-cycle decisions, and ensure co-transcriptional maturation of Pol II transcripts. Cdk7 engaged in transcription also appears to be regulated by phosphorylation within its own activation (T) loop. Here I review recent studies of CDK regulation in cell division and gene expression, and propose a model whereby mitogenic signals trigger a cascade of CDK T-loop phosphorylation that drives cells past the restriction (R) point, when continued cell-cycle progression becomes growth factor-independent. Because R-point control is frequently deregulated in cancer, the CAK-CDK pathway is an attractive target for chemical inhibition aimed at impeding the inappropriate commitment to cell division.
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85
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Abstract
The chicken coloboma mutation exhibits features similar to human congenital developmental malformations such as ocular coloboma, cleft-palate, dwarfism, and polydactyly. The coloboma-associated region and encoded genes were investigated using advanced genomic, genetic, and gene expression technologies. Initially, the mutation was linked to a 990 kb region encoding 11 genes; the application of the genetic and genomic tools led to a reduction of the linked region to 176 kb and the elimination of 7 genes. Furthermore, bioinformatics analyses of capture array-next generation sequence data identified genetic elements including SNPs, insertions, deletions, gaps, chromosomal rearrangements, and miRNA binding sites within the introgressed causative region relative to the reference genome sequence. Coloboma-specific variants within exons, UTRs, and splice sites were studied for their contribution to the mutant phenotype. Our compiled results suggest three genes for future studies. The three candidate genes, SLC30A5 (a zinc transporter), CENPH (a centromere protein), and CDK7 (a cyclin-dependent kinase), are differentially expressed (compared to normal embryos) at stages and in tissues affected by the coloboma mutation. Of these genes, two (SLC30A5 and CENPH) are considered high-priority candidate based upon studies in other vertebrate model systems.
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Affiliation(s)
- Elizabeth A. Robb
- Department of Animal Science, University of California Davis, Davis, California, United States of America
| | - Parker B. Antin
- Department of Molecular and Cellular Medicine, University of Arizona, Tucson, Arizona, United States of America
| | - Mary E. Delany
- Department of Animal Science, University of California Davis, Davis, California, United States of America
- * E-mail:
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86
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Gravells P, Tomita K, Booth A, Poznansky J, Porter AC. Chemical genetic analyses of quantitative changes in Cdk1 activity during the human cell cycle. Hum Mol Genet 2013; 22:2842-51. [DOI: 10.1093/hmg/ddt133] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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87
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Ganuza M, Santamaría D. Cdk7: open questions beyond the prevailing model. Cell Cycle 2012; 11:3519-20. [PMID: 22935708 PMCID: PMC3478293 DOI: 10.4161/cc.21888] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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