title: Proteomic analysis reveals that 14-3-3sigma is down-regulated in human breast cancer cells.
abstract: The class of molecular chaperones known as 14-3-3 is involved in the control of cellular growth by virtue of its apparent regulation of various signaling pathways, including the Raf/mitogen-activated protein kinase pathway. In breast cancer cells, the sigma form of 14-3-3 has been shown to interact with cyclin-dependent kinases and to control the rate of entry into mitosis. To test for a direct role for 14-3-3 in breast epithelial cell neoplasia, we have quantitated 14-3-3 protein levels using a proteomic approach based on two-dimensional electrophoresis and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF). We show here that 14-3-3sigma protein is strongly down-regulated in the prototypic breast cancer cell lines MCF-7 and MDA-MB-231 and in primary breast carcinomas as compared with normal breast epithelial cells. In contrast, levels of the alpha, beta, delta, or zeta isoforms of 14-3-3 were the same in both normal and transformed cells. The data support the idea that 14-3-3sigma is involved in the neoplastic transition of breast epithelial cells by virtue of its role as a tumor suppressor; as such, it may constitute a robust marker with clinical efficacy for this pathology.
authors.affiliation: Equipe Facteurs de Croissance, Laboratoire de Biologie du Développement, UPRES-EA 1033, Villeneuve d'Ascq, France.
authors.forename: A S
authors.initials: AS
authors.lastname: Vercoutter-Edouart
authors.forename: J
authors.initials: J
authors.lastname: Lemoine
authors.forename: X
authors.initials: X
authors.lastname: Le Bourhis
authors.forename: H
authors.initials: H
authors.lastname: Louis
authors.forename: B
authors.initials: B
authors.lastname: Boilly
authors.forename: V
authors.initials: V
authors.lastname: Nurcombe
authors.forename: F
authors.initials: F
authors.lastname: Révillion
authors.forename: J P
authors.initials: JP
authors.lastname: Peyrat
authors.forename: H
authors.initials: H
authors.lastname: Hondermarck
mesh_terms: D048948:14-3-3 Proteins; D001345:Autoradiography; D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000235:genetics; D001940:Breast / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D015180:Electrophoresis, Gel, Two-Dimensional; D004847:Epithelial Cells / Q000378:metabolism; D005092:Exonucleases; D005095:Exoribonucleases; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009363:Neoplasm Proteins; D014176:Protein Biosynthesis; D020033:Protein Isoforms; D011506:Proteins / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014407:Tumor Cells, Cultured
chemical_list: D048948:14-3-3 Proteins; D014408:Biomarkers, Tumor; D009363:Neoplasm Proteins; D020033:Protein Isoforms; D011506:Proteins; D005092:Exonucleases; D005095:Exoribonucleases; C413442:SFN protein, human