title: NHERF1/EBP50 controls morphogenesis of 3D colonic glands by stabilizing PTEN and ezrin-radixin-moesin proteins at the apical membrane.
abstract: Na(+)/H(+) exchanger 3 regulating factor 1/ezrin-radixin-moesin (ERM)-binding phosphoprotein 50 (NHERF1/EBP50), an adaptor molecule that interacts with the ERM-neurofibromatosis type 2 family of cytoskeletal proteins through its ERM-binding region and with phosphatase and tensin homolog (PTEN) and β-catenin through its PDZ domains, has been recently implicated in the progression of various human malignancies, including colorectal cancer (CRC). We report here that NHERF1 controls gland morphogenesis, as demonstrated in three-dimensional (3D) human intestinal glands developing from a single nonpolarized cell. Starting from the early two-cell developmental stage, NHERF1 concentrates at the cellular interface in a central membrane disc that marks the apical pole delimiting the forming lumen. NHERF1 depletion leads to severe disruption of the apical-basal polarity, with formation of enlarged and distorted cell spheroids devoid of a central lumen. This characteristic and the increased number of mitoses in NHERF1-depleted spheroids, including multipolar ones, mimic high-grade dysplasia lesions observed in CRC progression. NHERF1 ERM-binding or PDZ-domain mutants fail to localize apically and impair gland formation most likely by outcompeting endogenous ligands, with the latter mutant completely aborting gland development. Examination of NHERF1 ligands showed that even if both ezrin and moesin colocalized with NHERF1 at the apical membrane, moesin but not ezrin depletion disrupted morphogenesis similarly to NHERF1. NHERF1 depletion resulted also in membrane displacement of PTEN and nuclear translocation of β-catenin, events contributing to polarity loss and increased proliferation. These findings reveal an essential role of NHERF1 in epithelial morphogenesis and polarity and validate this 3D system for modeling the molecular changes observed in CRC.
authors.affiliation: Department of Pathology, The University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA. Electronic address: maria-magdalena.georgescu@phhs.org.
authors.forename: Maria-Magdalena
authors.initials: MM
authors.lastname: Georgescu
authors.affiliation: Department of Endocrine Neoplasia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Gilbert
authors.initials: G
authors.lastname: Cote
authors.affiliation: Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Nitin Kumar
authors.initials: NK
authors.lastname: Agarwal
authors.affiliation: Department of Pathology, The University of Texas Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Charles L
authors.initials: CL
authors.lastname: White
mesh_terms: D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D003106:Colon / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000473:pathology; D008840:Microfilament Proteins / Q000378:metabolism; D009024:Morphogenesis / Q000235:genetics*; D054731:PDZ Domains / Q000502:physiology; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D021381:Protein Transport; D017923:Sodium-Hydrogen Exchangers / Q000737:chemistry / Q000235:genetics*; D051176:beta Catenin / Q000378:metabolism; D000099149:Ezrin
chemical_list: D003598:Cytoskeletal Proteins; D008840:Microfilament Proteins; D051059:PTEN Phosphohydrolase; D010750:Phosphoproteins; D017923:Sodium-Hydrogen Exchangers; D051176:beta Catenin; D000099149:Ezrin; C093376:sodium-hydrogen exchanger regulatory factor; C071058:moesin