title: LMP1-induced cell death may contribute to the emergency of its oncogenic property.
abstract: OBJECTIVE
  Epstein-Barr Virus (EBV) Latent Membrane Protein 1 (LMP1) is linked to a variety of malignancies including Hodgkin's disease, lymphomas, nasopharyngeal and gastric carcinoma. LMP1 exerts its transforming or oncogenic activity mainly through the recruitment of intracellular adapters via LMP1 C-terminal Transformation Effector Sites (TES) 1 and 2. However, LMP1 is also reported to elicit significant cytotoxic effects in some other cell types. This cytotoxic effect is quite intriguing for an oncogenic protein, and it is unclear whether both functional aspects of the protein are related or mutually exclusive.
  
  
  RESULTS
  Using different ectopic expression systems in both Madin-Darby canine kidney (MDCK) epithelial cells and human embryonic kidney HEK-293 cells, we observe that LMP1 ectopic expression massively induces cell death. Furthermore, we show that LMP1-induced cytotoxicity mainly implies LMP1 C-terminal transformation effector sites and TRADD recruitment. However, stable expression of LMP1 in the same cells, is found to be associated with an increase of cell survival and an acquisition of epithelial mesenchymal transition phenotype as evidenced by morphological modifications, increased cell mobility, increased expression of MMP9 and decreased expression of E-cadherin. Our results demonstrate for the first time that the cytotoxic and oncogenic effects of LMP1 are not mutually exclusive but may operate sequentially. We suggest that in a total cell population, cells resistant to LMP1-induced cytotoxicity are those that could take advantage of LMP1 oncogenic activity by integrating LMP1 signaling into the pre-existent signaling network. Our findings thus reconcile the apparent opposite apoptotic and oncogenic effects described for LMP1 and might reflect what actually happens on LMP1-induced cell transformation after EBV infection in patients.
authors: CNRS UMR8161, Institut de Biologie de Lille, Institut Pasteur de Lille, IFR 142, Université Lille-Nord de France, Lille, France.
authors: Guillaume
authors: G
authors: Brocqueville
authors: Papa Alioune
authors: PA
authors: Ndour
authors: Tan-Sothéa
authors: TS
authors: Ouk
authors: Arnaud
authors: A
authors: Le Goff
authors: Caroline
authors: C
authors: De Witte
authors: Alexandra
authors: A
authors: Mougel
authors: Jean
authors: J
authors: Coll
authors: Véronique
authors: V
authors: Fafeur
authors: Xuefen
authors: X
authors: Le Bourhis
authors: Eric
authors: E
authors: Adriaenssens
mesh_terms: D000818:Animals; D016923:Cell Death; D002470:Cell Survival; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D004285:Dogs; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D058750:Epithelial-Mesenchymal Transition; D057809:HEK293 Cells; D004854:Herpesvirus 4, Human / Q000502:physiology; D006801:Humans; D061985:Madin Darby Canine Kidney Cells; D015513:Oncogene Proteins / Q000737:chemistry / Q000378:metabolism*; D021381:Protein Transport; D053199:TNF Receptor-Associated Death Domain Protein / Q000378:metabolism; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: C037662:EBV-associated membrane antigen, Epstein-Barr virus; D015513:Oncogene Proteins; D053199:TNF Receptor-Associated Death Domain Protein; D014763:Viral Matrix Proteins
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