DOCSLIB.ORG

Cell Cycle Transcription Control by Ubiquitin Signaling

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Cell Cycle Transcription Control by Ubiquitin Signaling CELL CYCLE TRANSCRIPTION CONTROL BY UBIQUITIN SIGNALING Anthony P. Arceci A dissertation submitted to the faculty at the University of North Carolina at Chapel Hill in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Curriculum in Genetics and Molecular Biology in the School of Medicine Chapel Hill 2019 Approved by: Ian J. Davis Channing J. Der Robert J. Duronio Brian Kuhlman Michael J. Emanuele © 2019 Anthony P. Arceci ALL RIGHTS RESERVED ii ABSTRACT Anthony P. Arceci: Cell Cycle Transcription Control by Ubiquitin Signaling (Under the direction of Michael J. Emanuele) The cell cycle is a tightly regulated series of molecular events which dictates proliferation. Both the timely activation of genes through transcription and destruction of proteins through the ubiquitin-proteasome system are integral to normal cell cycles. Dysregulation of these networks often underlie a variety of malignant diseases such as cancer. Forkhead box protein M1 (FOXM1) is an essential cell cycle transcription factor. FOXM1 regulates a transcriptional network that controls the G2/M transition and G1/S transition. Additionally, aberrant upregulation of the FOXM1 transcriptional network is linked to a variety of cancers. The kinases which activate FOXM1 are well explored, but the influence of the ubiquitin-proteasome system on FOXM1 remains unclear. Here, I described the role that two such enzymes, the E3 ubiquitin ligase CUL4-VPRBP and the deubiquitinating enzyme (DUB) USP21, have on the stability and activity of FOXM1 in both normal and dysregulated cell cycles. First, I demonstrate that FOXM1 degradation is enhanced by association with CUL4- VPRBP. Depletion of VPRBP enhances FOXM1 stability and causes mitotic entry defects. Interestingly, overexpression of VPRBP enhances both FOXM1 ubiquitination and transcriptional activity by a process that occurs independent of CUL4. Finally, VPRBP and FOXM1 levels are assessed in high-grade serous ovarian cancer (HGSOC) patient tumors, demonstrating a plausible mechanism for FOXM1 activation. iii Second, I demonstrate that FOXM1 is protected from degradation through association with the DUB USP21. Knockdown or overexpression of USP21 is able to destabilize or stabilize FOXM1, respectively, through deubiquitination of FOXM1. USP21 is able to influence mitotic entry and proliferation through regulating the FOXM1 transcriptional network. Furthermore, USP21 and FOXM1 are both significantly amplified in basal-like breast cancer with the knockdown of both sensitizing cells to the chemotherapy paclitaxel thus describing a novel combination treatment for this disease. Taken together, these results contribute to our understanding of how the ubiquitin- proteasome system positively and negatively regulates the abundance and activity of FOXM1. The research presented here further extends our understanding of the network of interactions regulating normal cell cycle dynamics and provide mechanistic and novel therapeutic insights into the promotion and treatment of cancer. iv To what great things await. v ACKNOWLEDGEMENTS Looking back on my journey to this point, it is clear to me that I did not arrive here without help and support along the way. Starting from the beginning of my academic journey, I would like to acknowledge my mother, Darlene, and friend, Ron, for believing in me from the start and helping me establish myself as I relocated from Winchendon, Massachusetts to Tucson, Arizona to take my first step in what would become a 12 year journey of discovery and learning. I would like to acknowledge my network of friends, Anthony, Armando, Brandon, Craig, Greg, Patrick and Wayne who became my band of brothers, helping me navigate through the journey. I would also like to acknowledge Dr. Kathleen Dixon, who fostered my passion for scientific inquiry and set me on the path to becoming a PhD. Dr. Angela Wandinger-Ness, Dr. Richard Cripps and Antonio Banuelos deserve recognition for providing me with the launching pad and experience to transition from the undergraduate level to the post-graduate level during my year at the University of New Mexico. I would like to acknowledge my colleagues in the lab Allie, Jen, Raj, Taylor, Thomas and Xianxi who were not only important participants in the research to follow, but also a great group of people to work with over the years. My partner, Amanda, deserves an incredible amount of recognition and has been with me through my entire graduate career. Without your love and support over the years I’m not sure if I would have made it. vi Finally, I would be remiss without recognizing my advisor, Dr. Michael Emanuele and the role that he played in guiding me to this point. Without your insight and knowledge to help me guide my research and humor and grace to make working in the lab fun, I surely would not have succeeded. I thank you all for the roles that you have played in my life. vii PREFACE In each of the following chapters portions of the work described were completed by other talented scientists and exceptional colleagues. Additionally, most chapters describe work that has been published and that I have permission to use as part of this dissertation. Chapter 2 describes work from a project which I made significant contributions to during my rotation and first year in the Emanuele lab and was ultimately completed by my colleague in the lab, Xianxi Wang. I contributed all experiments utilizing cell cycle analysis, RT-qPCR, and chromatin immunoprecipitation (ChIP). Additionally, I cloned some of the plasmids used in many of the cell biology assays described and provided critical revisions and suggestions to the manuscript throughout the peer-review process. Permission to include this article in its entirety is granted by the journal Molecular and Cellular Biology as described in their editorial policy (https://mcb.asm.org/content/editorial-policy). Chapter 3 describes work from a project in which I designed, conducted and analyzed the vast majority of experiments, wrote the manuscript and made most critical revisions throughout the peer-review process. The work described in Chapter 3 was published as an open-access article in Cell Reports. As such, I retain the copyright to this article as an author to include it in this dissertation in its entirety per editorial guidelines (https://www.elsevier.com/about/policies/copyright#Author-rights). viii TABLE OF CONTENTS LIST OF TABLES ...................................................................................................................... xii LIST OF FIGURES ................................................................................................................... xiii LIST OF ABBREVIATIONS ................................................................................................... xiv CHAPTER 1: INTRODUCTION ................................................................................................ 1 The Ubiquitin-Proteasome System .......................................................................................... 1 Background ............................................................................................................................. 1 Enzymes of the Ubiquitin-Proteasome System ........................................................................ 2 E3 Ubiquitin Ligases ............................................................................................................... 3 CRL4A and CRL4B ................................................................................................................. 5 DUBs ....................................................................................................................................... 6 USP21 ..................................................................................................................................... 8 The Cell Cycle ........................................................................................................................... 9 Historical Background ............................................................................................................ 9 Mechanisms of Control ......................................................................................................... 10 Cell Cycle Transcription by FOXM1 .................................................................................... 14 Background ........................................................................................................................... 14 Overview of FOXM1 Biology ................................................................................................ 15 Post-Translational Regulation of FOXM1 Through the Cell Cycle ..................................... 16 Ubiquitin-dependent Regulation of FOXM1 ......................................................................... 18 FOXM1 in Cancer ................................................................................................................. 19 ix CHAPTER 2: VPRBP/DCAF1 REGULATES THE DEGRADATION AND NONPROTEOLYTIC ACTIVATION OF THE CELL CYCLE TRANSCRIPTION FACTOR FOXM1 ...................................................................................................................... 25 Introduction ............................................................................................................................. 25 FOXM1 Stability is Regulated by CRL4VPRBP ....................................................................... 28 FOXM1 Interaction and Ubiquitylation
Load more

Recommended publications
  • Predicting FOXM1-Mediated Gene Regulation Through the Analysis of Genome-Wide FOXM1 Binding Sites in MCF-7, K562, SK-N-SH, GM12878 and ECC-1 Cell Lines
    International Journal of Molecular Sciences Article Predicting FOXM1-Mediated Gene Regulation through the Analysis of Genome-Wide FOXM1 Binding Sites in MCF-7, K562, SK-N-SH, GM12878 and ECC-1 Cell Lines 1, , 2, 1 3,4 Keunsoo Kang * y, Yoonjung Choi y, Hoo Hyun Kim , Kyung Hyun Yoo and Sungryul Yu 5,* 1 Department of Microbiology, College of Science & Technology, Dankook University, Cheonan 31116, Korea; [email protected] 2 Deargen Inc., Daejeon 34051, Korea; [email protected] 3 Laboratory of Biomedical Genomics, Department of Biological Sciences, Sookmyung Women’s University, Seoul 04310, Korea; [email protected] 4 Research Institute of Women’s Health, Sookmyung Women’s University, Seoul 04310, Korea 5 Department of Clinical Laboratory Science, Semyung University, Jecheon 27136, Korea * Correspondence: [email protected] (K.K.); [email protected] (S.Y.); Tel.: +82-41-550-3456 (K.K.); +82-43-649-1418 (S.Y.) These authors contributed equally to the work. y Received: 22 June 2020; Accepted: 24 August 2020; Published: 26 August 2020 Abstract: Forkhead box protein M1 (FOXM1) is a key transcription factor (TF) that regulates a common set of genes related to the cell cycle in various cell types. However, the mechanism by which FOXM1 controls the common gene set in different cellular contexts is unclear. In this study, a comprehensive meta-analysis of genome-wide FOXM1 binding sites in ECC-1, GM12878, K562, MCF-7, and SK-N-SH cell lines was conducted to predict FOXM1-driven gene regulation. Consistent with previous studies, different TF binding motifs were identified at FOXM1 binding sites, while the NFY binding motif was found at 81% of common FOXM1 binding sites in promoters of cell cycle-related genes.
    [Show full text]
  • Role of Fzr1 in Embryogenesis
    ROLE OF FZR1 IN EMBRYOGENESIS SEAH KAY YI MICHELLE BSC. (HONS I) PH.D THESIS Statement of Originality This thesis contains no material which has been accepted for the award for any other Degree or Diploma in any University or other tertiary institution and, to the best of my knowledge and belief, contains no material previously published or written by another person, except where due reference has been made in the text. I give consent to this copy of my thesis, when deposited in the University library, being made available for loan and photocopying subject to the provisions of the Copyright Act 1968. Seah Kay Yi Michelle 17th December 2012 Page | ii Acknowledgements I would like to sincerely express my appreciation and gratitude to my supervisors, Keith and Janet for giving me this opportunity and to share their wisdom and guidance throughout my PhD. I would also like to extend my thanks to all the lab members including Evan, Jess, Julie, Kyra, Nicole, Phoebe, Simon, Sophia, Suzanne and Yan. Thank you for your company and help throughout my PhD, it has made this an enjoyable experience in the lab. To my family especially Popo, Mummy and Daddy, thank you for the endless love, support and understanding that you have showered upon me. For that, I will be eternally grateful. Thank you for moulding me into the person that I am today, for without all of you, I will not be where I am today. I love you and will always be your little girl. To Clara, my BFF, thank you for your encouragements and to always be there for me.
    [Show full text]
  • Loss of the Mammalian APC/C Activator FZR1 Shortens G1 and Lengthens S Phase but Has Little Effect on Exit from Mitosis
    4208 Research Article Loss of the mammalian APC/C activator FZR1 shortens G1 and lengthens S phase but has little effect on exit from mitosis Reinhard Sigl1, Cornelia Wandke1, Veronika Rauch1, Jane Kirk2, Tim Hunt2 and Stephan Geley1,* 1Division of Molecular Pathophysiology, Biocenter, Innsbruck Medical University, Innsbruck, Austria 2Clare Hall Laboratories, Cancer Research UK, South Mimms, England, UK *Author for correspondence ([email protected]) Accepted 10 September 2009 Journal of Cell Science 122, 4208-4217 Published by The Company of Biologists 2009 doi:10.1242/jcs.054197 Summary The anaphase-promoting complex/cyclosome (APC/C) is knockdown of p53 in U2OS cells with inducible FZR1 siRNA essential for progression through mitosis. At anaphase onset, also failed to restore their proliferative capacity. Thus, the the APC/C requires the activator protein CDC20 to target proliferation defects are a direct consequence of the genetic securin and cyclin B1 for proteasome-dependent degradation, damage inflicted by loss of FZR1 function and are largely but then depends on the CDC20-related protein FZR1 (also independent of p53. In summary, mammalian FZR1 is not known as CDH1) to remain active until the onset of the next S required for the completion of mitosis, but is an important phase. To investigate the role of FZR1 in mammalian cells, we regulator of G1 phase and is required for efficient DNA used RNAi in human cell lines and conditional gene targeting replication in human and mouse somatic cells. in mouse embryonic fibroblasts. In neither case was FZR1 required for exit from mitosis, but in cells lacking FZR1, the Supplementary material available online at G1 phase was shortened and the S phase was prolonged.
    [Show full text]
  • Comparison of Gene Expression Response to Neutron and X-Ray Irradiation Using Mouse Blood Constantinos G
    Broustas et al. BMC Genomics (2017) 18:2 DOI 10.1186/s12864-016-3436-1 RESEARCHARTICLE Open Access Comparison of gene expression response to neutron and x-ray irradiation using mouse blood Constantinos G. Broustas1, Yanping Xu2, Andrew D. Harken2, Guy Garty2 and Sally A. Amundson1* Abstract Background: In the event of an improvised nuclear device detonation, the prompt radiation exposure would consist of photons plus a neutron component that would contribute to the total dose. As neutrons cause more complex and difficult to repair damage to cells that would result in a more severe health burden to affected individuals, it is paramount to be able to estimate the contribution of neutrons to an estimated dose, to provide information for those making treatment decisions. Results: Mice exposed to either 0.25 or 1 Gy of neutron or 1 or 4 Gy x-ray radiation were sacrificed at 1 or 7 days after exposure. Whole genome microarray analysis identified 7285 and 5045 differentially expressed genes in the blood of mice exposed to neutron or x-ray radiation, respectively. Neutron exposure resulted in mostly downregulated genes, whereas x-rays showed both down- and up-regulated genes. A total of 34 differentially expressed genes were regulated in response to all ≥1 Gy exposures at both times. Of these, 25 genes were consistently downregulated at days 1 and 7, whereas 9 genes, including the transcription factor E2f2, showed bi-directional regulation; being downregulated at day 1, while upregulated at day 7. Gene ontology analysis revealed that genes involved in nucleic acid metabolism processes were persistently downregulated in neutron irradiated mice, whereas genes involved in lipid metabolism were upregulated in x-ray irradiated animals.
    [Show full text]
  • Phosphorylation of the Anaphase Promoting Complex
    www.nature.com/scientificreports OPEN Phosphorylation of the Anaphase Promoting Complex activator FZR1/CDH1 is required for Meiosis II entry in mouse male germ cell Nobuhiro Tanno1,2, Shinji Kuninaka2, Sayoko Fujimura3, Kazumasa Takemoto1, Kaho Okamura1, Naoki Takeda4, Kimi Araki4,5, Masatake Araki4, Hideyuki Saya2 & Kei-ichiro Ishiguro1 ✉ FZR1/CDH1 is an activator of Anaphase promoting complex/Cyclosome (APC/C), best known for its role as E3 ubiquitin ligase that drives the cell cycle. APC/C activity is regulated by CDK-mediated phosphorylation of FZR1 during mitotic cell cycle. Although the critical role of FZR1 phosphorylation has been shown mainly in yeast and in vitro cell culture studies, its biological signifcance in mammalian tissues in vivo remained elusive. Here, we examined the in vivo role of FZR1 phosphorylation using a mouse model, in which non-phosphorylatable substitutions were introduced in the putative CDK- phosphorylation sites of FZR1. Although ablation of FZR1 phosphorylation did not show substantial consequences in mouse somatic tissues, it led to severe testicular defects resulting in male infertility. In the absence of FZR1 phosphorylation, male juvenile germ cells entered meiosis normally but failed to enter meiosis II or form diferentiated spermatids. In aged testis, male mutant germ cells were overall abolished, showing Sertoli cell-only phenotype. In contrast, female mutants showed apparently normal progression of meiosis. The present study demonstrated that phosphorylation of FZR1 is required for temporal regulation of APC/C activity at meiosis II entry, and for maintenance of spermatogonia, which raised an insight into the sexual dimorphism of FZR1-regulation in germ cells. Anaphase promoting complex/Cyclosome (APC/C) controls timely transitions of mitotic cell cycle phases by pro- moting ubiquitylation and degradation of many key cell cycle regulators1.
    [Show full text]
  • Biocreative 2012 Proceedings
    Proceedings of 2012 BioCreative Workshop April 4 -5, 2012 Washington, DC USA Editors: Cecilia Arighi Kevin Cohen Lynette Hirschman Martin Krallinger Zhiyong Lu Carolyn Mattingly Alfonso Valencia Thomas Wiegers John Wilbur Cathy Wu 2012 BioCreative Workshop Proceedings Table of Contents Preface…………………………………………………………………………………….......... iv Committees……………………………………………………………………………………... v Workshop Agenda…………………………………………………………………………….. vi Track 1 Collaborative Biocuration-Text Mining Development Task for Document Prioritization for Curation……………………………………..……………………………………………….. 2 T Wiegers, AP Davis, and CJ Mattingly System Description for the BioCreative 2012 Triage Task ………………………………... 20 S Kim, W Kim, CH Wei, Z Lu and WJ Wilbur Ranking of CTD articles and interactions using the OntoGene pipeline ……………..….. 25 F Rinaldi, S Clematide and S Hafner Selection of relevant articles for curation for the Comparative Toxicogenomic Database…………………………………………………………………………………………. 31 D Vishnyakova, E Pasche and P Ruch CoIN: a network exploration for document triage………………………………................... 39 YY Hsu and HY Kao DrTW: A Biomedical Term Weighting Method for Document Recommendation ………... 45 JH Ju, YD Chen and JH Chiang C2HI: a Complete CHemical Information decision system……………………………..….. 52 CH Ke, TLM Lee and JH Chiang Track 2 Overview of BioCreative Curation Workshop Track II: Curation Workflows….…………... 59 Z Lu and L Hirschman WormBase Literature Curation Workflow ……………………………………………………. 66 KV Auken, T Bieri, A Cabunoc, J Chan, Wj Chen, P Davis, A Duong, R Fang, C Grove, Tw Harris, K Howe, R Kishore, R Lee, Y Li, Hm Muller, C Nakamura, B Nash, P Ozersky, M Paulini, D Raciti, A Rangarajan, G Schindelman, Ma Tuli, D Wang, X Wang, G Williams, K Yook, J Hodgkin, M Berriman, R Durbin, P Kersey, J Spieth, L Stein and Pw Sternberg Literature curation workflow at The Arabidopsis Information Resource (TAIR)…..……… 72 D Li, R Muller, TZ Berardini and E Huala Summary of Curation Process for one component of the Mouse Genome Informatics Database Resource …………………………………………………………………………....
    [Show full text]
  • TOPDRIVER: the Novel Identifier of Cancer Driver Genes in Gastric
    Razavi et al. Applied Network Science (2019) 4:83 Applied Network Science https://doi.org/10.1007/s41109-019-0200-x RESEARCH Open Access TOPDRIVER: the novel identifier of cancer driver genes in Gastric cancer and Melanoma Seyed Mohammad Razavi1,2, Farzaneh Rami2, Seyede Houri Razavi1,2 and Changiz Eslahchi1,2* *Correspondence: [email protected] Abstract 1Computer Science Department, Nowadays, research has found a strong relationship between genomic status and Mathematical sciences faculty, Shahid Beheshti University, Tehran, occurrence of disease. Cancer is one of the most common diseases that leads to a high Iran annual mortality rate worldwide, and the disease’s genetic content remains 2School of Biological Sciences, challenging. Detecting driver genes of different cancers could help in early diagnosis Institute for Research in Fundamental Sciences (IPM), and treatment. In this paper, we proposed TOPDRIVER, a network-based algorithm, to Tehran, Iran detect cancer driver genes in cancers. An initial network was constructed by integrating four different omic datasets: HPRD, NCBI, KEGG, and GTEx. This integration created a gene similarity profile that provided a comprehensive perspective of gene interaction in each subtype of cancer and allocated weights to the edges of the network. The vertex scores were calculated using a gene-disease association dataset (DisGeNet) and a molecular functional disease similarity. In this step, the genes network was jagged and faced with a zero-one gap problem. A diffusion kernel was implemented to smooth the vertex scores to overcome this problem. Finally, potential driver genes were extracted according to the topology of the network, genes overall biological functions, and their involvement in cancer pathways.
    [Show full text]
  • Concordance of Copy Number Loss and Down-Regulation of Tumor Suppressor Genes: a Pan-Cancer Study Min Zhao1 and Zhongming Zhao2,3,4,5*
    The Author(s) BMC Genomics 2016, 17(Suppl 7):532 DOI 10.1186/s12864-016-2904-y RESEARCH Open Access Concordance of copy number loss and down-regulation of tumor suppressor genes: a pan-cancer study Min Zhao1 and Zhongming Zhao2,3,4,5* From The International Conference on Intelligent Biology and Medicine (ICIBM) 2015 Indianapolis, IN, USA. 13-15 November 2015 Abstract Background: Tumor suppressor genes (TSGs) encode the guardian molecules to control cell growth. The genomic alteration of TSGs may cause tumorigenesis and promote cancer progression. So far, investigators have mainly studied the functional effects of somatic single nucleotide variants in TSGs. Copy number variation (CNV) is another important form of genetic variation, and is often involved in cancer biology and drug treatment, but studies of CNV in TSGs are less represented in literature. In addition, there is a lack of a combinatory analysis of gene expression and CNV in this important gene set. Such a study may provide more insights into the relationship between gene dosage and tumorigenesis. To meet this demand, we performed a systematic analysis of CNVs and gene expression in TSGs to provide a systematic view of CNV and gene expression change in TSGs in pan-cancer. Results: We identified 1170 TSGs with copy number gain or loss in 5846 tumor samples. Among them, 207 TSGs tended to have copy number loss (CNL), from which fifteen CNL hotspot regions were identified. The functional enrichment analysis revealed that the 207 TSGs were enriched in cancer-related pathways such as P53 signaling pathway and the P53 interactome.
    [Show full text]
  • FOXM1 Binds Directly to Non-Consensus Sequences in the Human Genome Deborah A
    Sanders et al. Genome Biology (2015) 16:130 DOI 10.1186/s13059-015-0696-z RESEARCH Open Access FOXM1 binds directly to non-consensus sequences in the human genome Deborah A. Sanders1,4, Michael V. Gormally1, Giovanni Marsico1, Dario Beraldi1, David Tannahill1 and Shankar Balasubramanian1,2,3* Abstract Background: The Forkhead (FKH) transcription factor FOXM1 is a key regulator of the cell cycle and is overexpressed in most types of cancer. FOXM1, similar to other FKH factors, binds to a canonical FKH motif in vitro. However, genome-wide mapping studies in different cell lines have shown a lack of enrichment of the FKH motif, suggesting an alternative mode of chromatin recruitment. We have investigated the role of direct versus indirect DNA binding in FOXM1 recruitment by performing ChIP-seq with wild-type and DNA binding deficient FOXM1. Results: An in vitro fluorescence polarization assay identified point mutations in the DNA binding domain of FOXM1 that inhibit binding to a FKH consensus sequence. Cell lines expressing either wild-type or DNA binding deficient GFP-tagged FOXM1 were used for genome-wide mapping studies comparing the distribution of the DNA binding deficient protein to the wild-type. This shows that interaction of the FOXM1 DNA binding domain with target DNA is essential for recruitment. Moreover, analysis of the protein interactome of wild-type versus DNA binding deficient FOXM1 shows that the reduced recruitment is not due to inhibition of protein-protein interactions. Conclusions: A functional DNA binding domain is essential for FOXM1 chromatin recruitment. Even in FOXM1 mutants with almost complete loss of binding, the protein-protein interactions and pattern of phosphorylation are largely unaffected.
    [Show full text]
  • FZR1 As a Novel Biomarker for Breast Cancer Neoadjuvant Chemotherapy
    Liu et al. Cell Death and Disease (2020) 11:804 https://doi.org/10.1038/s41419-020-03004-9 Cell Death & Disease ARTICLE Open Access FZR1 as a novel biomarker for breast cancer neoadjuvant chemotherapy prediction Shuo Liu1,HaobinWang2,JunLi1,JianhuiZhang3,JianWu2,YiLi4, Yongjun Piao1,LeitingPan5,RongXiang 1,6 and Shijing Yue 1 Abstract The concept of breast-conserving surgery is a remarkable achievement of breast cancer therapy. Neoadjuvant chemotherapy is being used increasingly to shrink the tumor prior to surgery. Neoadjuvant chemotherapy is reducing the tumor size to make the surgery with less damaging to surrounding tissue and downstage locally inoperable disease to operable. However, non-effective neoadjuvant chemotherapy could increase the risks of delaying surgery, develop unresectable disease and metastatic tumor spread. The biomarkers for predicting the neoadjuvant chemotherapy effect are scarce in breast cancer treatment. In this study, we identified that FZR1 can be a novel biomarker for breast cancer neoadjuvant chemotherapy according to clinical patient cohort evaluation and molecular mechanism investigation. Transcriptomic data analysis indicated that the expression of FZR1 is correlated with the effect of neoadjuvant chemotherapy. Mechanistically, we demonstrate that FZR1 is pivotal to the chemotherapy drugs induced apoptosis and cell cycle arrest. FZR1 is involved in the stability of p53 by impairing the phosphorylation at ser15 site. We demonstrate that the expression of FZR1 detected by quantification of IHC can be an effective predictor of neoadjuvant chemotherapy in animal experiment and clinical patient cohort. To obtain more benefit for breast cancer patient, we propose that the FZR1 IHC score using at the clinical to predict the effect of neoadjuvant chemotherapy.
    [Show full text]
  • Cell Cycle Arrest Through Indirect Transcriptional Repression by P53: I Have a DREAM
    Cell Death and Differentiation (2018) 25, 114–132 Official journal of the Cell Death Differentiation Association OPEN www.nature.com/cdd Review Cell cycle arrest through indirect transcriptional repression by p53: I have a DREAM Kurt Engeland1 Activation of the p53 tumor suppressor can lead to cell cycle arrest. The key mechanism of p53-mediated arrest is transcriptional downregulation of many cell cycle genes. In recent years it has become evident that p53-dependent repression is controlled by the p53–p21–DREAM–E2F/CHR pathway (p53–DREAM pathway). DREAM is a transcriptional repressor that binds to E2F or CHR promoter sites. Gene regulation and deregulation by DREAM shares many mechanistic characteristics with the retinoblastoma pRB tumor suppressor that acts through E2F elements. However, because of its binding to E2F and CHR elements, DREAM regulates a larger set of target genes leading to regulatory functions distinct from pRB/E2F. The p53–DREAM pathway controls more than 250 mostly cell cycle-associated genes. The functional spectrum of these pathway targets spans from the G1 phase to the end of mitosis. Consequently, through downregulating the expression of gene products which are essential for progression through the cell cycle, the p53–DREAM pathway participates in the control of all checkpoints from DNA synthesis to cytokinesis including G1/S, G2/M and spindle assembly checkpoints. Therefore, defects in the p53–DREAM pathway contribute to a general loss of checkpoint control. Furthermore, deregulation of DREAM target genes promotes chromosomal instability and aneuploidy of cancer cells. Also, DREAM regulation is abrogated by the human papilloma virus HPV E7 protein linking the p53–DREAM pathway to carcinogenesis by HPV.Another feature of the pathway is that it downregulates many genes involved in DNA repair and telomere maintenance as well as Fanconi anemia.
    [Show full text]
  • The APC/C E3 Ligase Complex Activator FZR1 Restricts BRAF Oncogenic Function
    Published OnlineFirst February 7, 2017; DOI: 10.1158/2159-8290.CD-16-0647 RESEARCH ARTICLE The APC/C E3 Ligase Complex Activator FZR1 Restricts BRAF Oncogenic Function Lixin Wan1,2, Ming Chen3, Juxiang Cao4, Xiangpeng Dai1, Qing Yin2, Jinfang Zhang1, Su-Jung Song3, Ying Lu5, Jing Liu1,6, Hiroyuki Inuzuka1, Jesse M. Katon3, Kelsey Berry3, Jacqueline Fung3, Christopher Ng3, Pengda Liu1, Min Sup Song7, Lian Xue2, Roderick T. Bronson8, Marc W. Kirschner5, Rutao Cui4, Pier Paolo Pandolfi3, and Wenyi Wei1 Downloaded from cancerdiscovery.aacrjournals.org on September 28, 2021. © 2017 American Association for Cancer Research. Published OnlineFirst February 7, 2017; DOI: 10.1158/2159-8290.CD-16-0647 ABSTRACT BRAF drives tumorigenesis by coordinating the activation of the RAS/RAF/MEK/ERK oncogenic signaling cascade. However, upstream pathways governing BRAF kinase activity and protein stability remain undefined. Here, we report that in primary cells with active APCFZR1, APCFZR1 earmarks BRAF for ubiquitination-mediated proteolysis, whereas in cancer cells with APC-free FZR1, FZR1 suppresses BRAF through disrupting BRAF dimerization. Moreover, we identified FZR1 as a direct target of ERK and CYCLIN D1/CDK4 kinases. Phosphorylation of FZR1 inhibits APCFZR1, leading to elevation of a cohort of oncogenic APCFZR1 substrates to facilitate melanomagenesis. Importantly, CDK4 and/or BRAF/MEK inhibitors restore APCFZR1 E3 ligase activity, which might be critical for their clinical effects. Furthermore, FZR1 depletion cooperates with AKT hyperactivation to transform primary mel- anocytes, whereas genetic ablation of Fzr1 synergizes with Pten loss, leading to aberrant coactivation of BRAF/ERK and AKT signaling in mice. Our findings therefore reveal a reciprocal suppression mechanism between FZR1 and BRAF in controlling tumorigenesis.
    [Show full text]