Ecd as a regulator of cell cycle and breast oncogenesis

Summary

Principal Investigator: Vimla Band
Abstract: DESCRIPTION (provided by applicant): Precisely regulated cell proliferation is essential for embryonic development as well as homeostasis in adult organs and tissues, whereas uncontrolled cell proliferation is a hallmark of cancer. Thus, elucidating how the cell cycle machinery is controlled is an important area of research in cancer cell biology. A large body of evidence has established a basic paradigm of the control of cell cycle progression involving the Retinoblastoma (Rb) protein family in conjunction with the E2F family of transcription factors. During G0/G1, interaction of hypo-phosphorylated Rb proteins with E2Fs prevents the transcription of E2F target genes. Cyclin-CDK complexes generated during cell cycle progression hyper-phosphorylate Rb, leading to release of Rb from E2Fs;this allows E2F target gene transcription and cell cycle progression. We have identified the mammalian ortholog of Drosophila ecdysoneless (Ecd) protein as a novel and essential regulator of Rb-E2F-dependent cell cycle progression. Loss of Ecd retards the separation of Rb from E2F, arrests cells at G1/S boundary and prevents cell cycle progression. These findings have led to a new model that represents a fundamental shift in the Rb-E2F-dependent cell cycle control paradigm. Notably, Ecd is overexpressed in breast cancer cell lines as well as in ductal carcinoma in situ and infiltrating ductal carcinomas of the breast. Notably, Ecd overexpression produced two opposite phenotypes: p53-dependent senescence in fibroblasts, compared to rapid transit through cell cycle in immortal human mammary epithelial cells (hMECs) that lack p16;and co-overexpression of Ecd with activated Ras induced a dramatic hyper-proliferation and aberrant branching of hMECs in three-dimensional culture. These features are reminiscent of senescence induced by oncogenes, such as Ras. These findings lead us to hypothesize that Ecd is a novel and essential component of Rb-E2F-dependent control of cell cycle progression, and alterations in the levels and/or function of Ecd contribute to oncogenic transformation. Here, we will address these hypotheses using unique and innovative cellular and animal models established by our team. We will examine the structural basis of the role of Ecd in cell cycle progression and its regulation. We will characterize Ecd-induced cellular senescence. We will analyze the consequences of Ecd overexpression in promoting mammary oncogenesis in vitro and in vivo using inducible transgenic mice. Finally, we will determine if Ecd is essential for mammary tumor initiation, progression and maintenance driven by a human breast cancer-relevant oncogene ErbB2 using mammary-specific deletion of Ecd in Ecd-floxed mice. A successful outcome of our studies will elucidate the role of a novel cell cycle control regulator in breast cancer with broad implications for oncogenesis in human cancer, and could help establish Ecd as a potential therapeutic target in cancer. PUBLIC HEALTH RELEVANCE: This proposal will investigate a new and paradigm-shifting mechanism of how cell cycle is regulated. Ecd, the novel cell cycle regulatory protein under study is overexpressed in human breast cancers and initial studies indicate that forced expression of Ecd in normal breast cells pushes them along tumorigenesis. Our studies are therefore focused on investigating the role of Ecd in breast cancer using unique cellular and animal models specifically created for this project. A successful outcome of our studies will likely have broad implications for understanding mechanisms of human cancer and could help establish Ecd as a potential therapeutic target. While our studies are focused on breast cancer, these studies are likely to be of broad significance for human cancer biology and other diseases given the frequent alterations in cell cycle regulatory mechanisms in human cancers and other pathological conditions.
Funding Period: 2011-03-01 - 2016-02-29
more information: NIH RePORT

Top Publications

  1. pmc Breast cancer subtypes: two decades of journey from cell culture to patients
    Xiangshan Zhao
    Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA
    Adv Exp Med Biol 720:135-44. 2011
  2. pmc Derivation of myoepithelial progenitor cells from bipotent mammary stem/progenitor cells
    Xiangshan Zhao
    Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
    PLoS ONE 7:e35338. 2012
  3. pmc Mammalian alteration/deficiency in activation 3 (Ada3) is essential for embryonic development and cell cycle progression
    Shakur Mohibi
    Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198 5805, USA
    J Biol Chem 287:29442-56. 2012
  4. pmc Overexpression of ecdysoneless in pancreatic cancer and its role in oncogenesis by regulating glycolysis
    Parama Dey
    Department of Biochemistry and Molecular Biology, Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
    Clin Cancer Res 18:6188-98. 2012
  5. pmc Protein tyrosine kinase regulation by ubiquitination: critical roles of Cbl-family ubiquitin ligases
    Bhopal Mohapatra
    Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
    Biochim Biophys Acta 1833:122-39. 2013
  6. pmc Alteration/deficiency in activation-3 (Ada3) plays a critical role in maintaining genomic stability
    Sameer Mirza
    Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA
    Cell Cycle 11:4266-74. 2012
  7. pmc A comprehensive, multi-scale dynamical model of ErbB receptor signal transduction in human mammary epithelial cells
    Tomás Helikar
    Department of Mathematics, University of Nebraska at Omaha, Omaha, Nebraska, USA
    PLoS ONE 8:e61757. 2013
  8. pmc Distinct effects of EGFR ligands on human mammary epithelial cell differentiation
    Chandrani Mukhopadhyay
    Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
    PLoS ONE 8:e75907. 2013

Research Grants

  1. INTEGRIN SIGNALING DURING BREAST TUMORIGENESIS
    Filippo G Giancotti; Fiscal Year: 2013
  2. Regulation of Tumor Metabolism by Retinoblastoma Protein
    Brian F Clem; Fiscal Year: 2013
  3. Automatic Three Dimensional (3D) Registration for Enhanced Cancer Management
    CHARLES RAYMOND MEYER; Fiscal Year: 2013
  4. Nek2 and NPM in centrosome amplification
    Harold I Saavedra; Fiscal Year: 2013
  5. Impact of Cyclin D1 Isoforms in Breast Cancer
    Richard G Pestell; Fiscal Year: 2013
  6. MECHANISMS OF BREAST DEVELOPMENT AND CARCINOGENESIS
    Robert A Weinberg; Fiscal Year: 2013

Detail Information

Publications9

  1. pmc Breast cancer subtypes: two decades of journey from cell culture to patients
    Xiangshan Zhao
    Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA
    Adv Exp Med Biol 720:135-44. 2011
    ....
  2. pmc Derivation of myoepithelial progenitor cells from bipotent mammary stem/progenitor cells
    Xiangshan Zhao
    Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
    PLoS ONE 7:e35338. 2012
    ..Availability of immortal MPCs should allow a more definitive analysis of their potential to give rise to claudin-low breast cancer subtype and facilitate biological and molecular/biochemical studies of this disease...
  3. pmc Mammalian alteration/deficiency in activation 3 (Ada3) is essential for embryonic development and cell cycle progression
    Shakur Mohibi
    Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198 5805, USA
    J Biol Chem 287:29442-56. 2012
    ..Taken together, we provide evidence for a critical role of Ada3 in embryogenesis and cell cycle progression as an essential component of HAT complex...
  4. pmc Overexpression of ecdysoneless in pancreatic cancer and its role in oncogenesis by regulating glycolysis
    Parama Dey
    Department of Biochemistry and Molecular Biology, Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
    Clin Cancer Res 18:6188-98. 2012
    ..To study the expression and function of a novel cell-cycle regulatory protein, human ecdysoneless (Ecd), during pancreatic cancer pathogenesis...
  5. pmc Protein tyrosine kinase regulation by ubiquitination: critical roles of Cbl-family ubiquitin ligases
    Bhopal Mohapatra
    Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
    Biochim Biophys Acta 1833:122-39. 2013
    ....
  6. pmc Alteration/deficiency in activation-3 (Ada3) plays a critical role in maintaining genomic stability
    Sameer Mirza
    Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE, USA
    Cell Cycle 11:4266-74. 2012
    ..Taken together, these findings provide evidence for a novel role for Ada3 in maintenance of the DNA repair process and genomic stability...
  7. pmc A comprehensive, multi-scale dynamical model of ErbB receptor signal transduction in human mammary epithelial cells
    Tomás Helikar
    Department of Mathematics, University of Nebraska at Omaha, Omaha, Nebraska, USA
    PLoS ONE 8:e61757. 2013
    ..Our subsequent laboratory experiments also suggest increased internalization of EGFR upon Src overexpression under EGF-deprived conditions, further supporting this model-generated hypothesis...
  8. pmc Distinct effects of EGFR ligands on human mammary epithelial cell differentiation
    Chandrani Mukhopadhyay
    Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
    PLoS ONE 8:e75907. 2013
    ..The present data validate the utility of the K5(+)K19(-) hMEC cells for modeling key features of human MEC differentiation. This system should be useful in studying molecular/biochemical mechanisms of human MEC differentiation. ..

Research Grants30

  1. INTEGRIN SIGNALING DURING BREAST TUMORIGENESIS
    Filippo G Giancotti; Fiscal Year: 2013
    ..Mouse genetics will be used to determine if [unreadable]4 and FAK cooperate in vivo to promote ErbB2-initiated mammary tumorigenesis. ..
  2. Regulation of Tumor Metabolism by Retinoblastoma Protein
    Brian F Clem; Fiscal Year: 2013
    ..2. To determine the effects of Rb1 deletion on glucose/glutamine metabolism and growth of lung adenocarcinomas in vivo. 3. To correlate the loss of Rb function with changes in the 13C-glucose utilization by human lung tumors in vivo. ..
  3. Automatic Three Dimensional (3D) Registration for Enhanced Cancer Management
    CHARLES RAYMOND MEYER; Fiscal Year: 2013
    ..Generalized techniques that support controlling and optimizing these tradeoffs during dynamic imaging in MRI are very important. ..
  4. Nek2 and NPM in centrosome amplification
    Harold I Saavedra; Fiscal Year: 2013
    ..Specific aim 3 will address how interfering with the classical pathway in vivo prevents centrosome amplification in pre-malignancy and suppresses mammary tumorigenesis. ..
  5. Impact of Cyclin D1 Isoforms in Breast Cancer
    Richard G Pestell; Fiscal Year: 2013
    ..Given this information, it is essential to decipher the impact of cyclin D1b on breast cancer development, progression and response to therapy. ..
  6. MECHANISMS OF BREAST DEVELOPMENT AND CARCINOGENESIS
    Robert A Weinberg; Fiscal Year: 2013
    ..abstract_text> ..