title: TfR2 expression in human colon carcinomas.
abstract: Different proteins regulate iron metabolism at the level of various tissues. Among these is a second transferrin receptor (TfR2) that seems to play a key role in the regulation of iron homeostasis. Although TfR2 expression in normal tissues is restricted at the level of the liver, we observed that TfR2 is frequently expressed in cancer cell lines. Taking advantage of this observation we investigated TfR2 expression in primary colon cancers, and showed that this receptor is expressed in about 26% of cases. TfR2 expression in colon cancer is not related to histological grade, but is preferentially associated with mucinous tumors. In colon cancer cell lines, TfR2 is localized in membrane lipid rafts, induces ERK1/ERK2 phosphorylation, when activated by its ligand transferring, and is preferentially expressed during S-M phases of the cell cycle. The presence of TfR2 on the membrane of colon cancer cells may contribute the growth advantage to these cells.
authors.affiliation: Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Calzolari
authors.forename: Silvia
authors.initials: S
authors.lastname: Deaglio
authors.forename: Elena
authors.initials: E
authors.lastname: Maldi
authors.forename: Paola
authors.initials: P
authors.lastname: Cassoni
authors.forename: Fabio
authors.initials: F
authors.lastname: Malavasi
authors.forename: Ugo
authors.initials: U
authors.lastname: Testa
mesh_terms: D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D002453:Cell Cycle / Q000502:physiology; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D006801:Humans; D007501:Iron / Q000378:metabolism; D021962:Membrane Microdomains / Q000378:metabolism*; D011990:Receptors, Transferrin / Q000378:metabolism*
chemical_list: D011990:Receptors, Transferrin; C503640:TFR2 protein, human; D007501:Iron; D048049:Extracellular Signal-Regulated MAP Kinases