title: LASP-1: a nuclear hub for the UHRF1-DNMT1-G9a-Snail1 complex.
abstract: Nuclear LASP-1 (LIM and SH3 protein-1) has a direct correlation with overall survival of breast cancer patients. In this study, immunohistochemical analysis of a human breast TMA showed that LASP-1 is absent in normal human breast epithelium but the expression increases with malignancy and is highly nuclear in aggressive breast cancer. We investigated whether the chemokines and growth factors present in the tumor microenvironment could trigger nuclear translocation of LASP-1.Treatment of human breast cancer cells with CXCL12, EGF and HRG, and HMEC-CXCR2 cells with CXCL8 facilitated nuclear shuttling of LASP-1. Data from the biochemical analysis of the nuclear and cytosolic fractions further confirmed the nuclear translocation of LASP-1 upon chemokine and growth factor treatment. CXCL12-dependent nuclear import of LASP-1 could be blocked by CXCR4 antagonist, AMD-3100. Knock down of LASP-1 resulted in alterations in gene expression leading to an increased level of cell-junction and extracellular matrix proteins and an altered cytokine secretory profile. Three-dimensional cultures of human breast cancer cells on Matrigel revealed an altered colony growth, morphology and arborization pattern in LASP-1 knockdown cells. Functional analysis of the LASP-1 knockdown cells revealed increased adhesion to collagen IV and decreased invasion through the Matrigel. Proteomic analysis of immunoprecipitates of LASP-1 and subsequent validation approaches revealed that LASP-1 associated with the epigenetic machinery especially UHRF1, DNMT1, G9a and the transcription factor Snail1. Interestingly, LASP-1 associated with UHRF1, G9a, Snail1 and di- and tri-methylated histoneH3 in a CXCL12-dependent manner based on immunoprecipitation and proximity ligation assays. LASP-1 also directly bound to Snail1 which may stabilize Snail1. Thus, nuclear LASP-1 appears to functionally serve as a hub for the epigenetic machinery.
authors.affiliation: Department of Cancer Biology, Vanderbilt University, School of Medicine, Nashville, TN, USA.
authors.forename: N
authors.initials: N
authors.lastname: Duvall-Noelle
authors.affiliation: Department of Cancer Biology, Vanderbilt University, School of Medicine, Nashville, TN, USA.
authors.forename: A
authors.initials: A
authors.lastname: Karwandyar
authors.affiliation: Department of Cancer Biology, Vanderbilt University, School of Medicine, Nashville, TN, USA.|Tennessee Valley Healthcare System, Department of Veterans Affairs, Nashville, TN, USA.
authors.forename: A
authors.initials: A
authors.lastname: Richmond
authors.affiliation: Department of Cancer Biology, Vanderbilt University, School of Medicine, Nashville, TN, USA.
authors.forename: D
authors.initials: D
authors.lastname: Raman
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000235:genetics; D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics* / Q000378:metabolism; D001596:Benzylamines; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D054377:Chemokine CXCL12 / Q000037:antagonists & inhibitors; D000080027:Cyclams; D003598:Cytoskeletal Proteins / Q000235:genetics* / Q000378:metabolism; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics* / Q000378:metabolism; D044127:Epigenesis, Genetic; D055785:Gene Knockdown Techniques; D006571:Heterocyclic Compounds / Q000008:administration & dosage; D006649:Histocompatibility Antigens / Q000235:genetics* / Q000378:metabolism; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics* / Q000378:metabolism; D006657:Histones / Q000235:genetics; D006801:Humans; D060588:LIM Domain Proteins / Q000235:genetics* / Q000378:metabolism; D011379:Prognosis; D040901:Proteomics; D015398:Signal Transduction / Q000235:genetics; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D059016:Tumor Microenvironment / Q000235:genetics; D044767:Ubiquitin-Protein Ligases
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D001596:Benzylamines; D022762:CCAAT-Enhancer-Binding Proteins; C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D000080027:Cyclams; D003598:Cytoskeletal Proteins; D006571:Heterocyclic Compounds; D006649:Histocompatibility Antigens; D006657:Histones; C096353:LASP1 protein, human; D060588:LIM Domain Proteins; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; C000619380:DNMT1 protein, human; C445405:EHMT2 protein, human; D011495:Histone-Lysine N-Methyltransferase; C406364:UHRF1 protein, human; D044767:Ubiquitin-Protein Ligases; C088327:plerixafor