title: Regulation of epidermal growth factor receptor signaling in human cancer cells by microRNA-7.
abstract: The epidermal growth factor receptor (EGFR) is frequently overexpressed in cancer and is an important therapeutic target. Aberrant expression and function of microRNAs have been associated with tumorigenesis. Bioinformatic predictions suggest that the human EGFR mRNA 3'-untranslated region contains three microRNA-7 (miR-7) target sites, which are not conserved across mammals. We found that miR-7 down-regulates EGFR mRNA and protein expression in cancer cell lines (lung, breast, and glioblastoma) via two of the three sites, inducing cell cycle arrest and cell death. Because miR-7 was shown to decrease EGFR mRNA expression, we used microarray analysis to identify additional mRNA targets of miR-7. These included Raf1 and multiple other genes involved in EGFR signaling and tumorigenesis. Furthermore, miR-7 attenuated activation of protein kinase B (Akt) and extracellular signal-regulated kinase 1/2, two critical effectors of EGFR signaling, in different cancer cell lines. These data establish an important role for miR-7 in controlling mRNA expression and indicate that miR-7 has the ability to coordinately regulate EGFR signaling in multiple human cancer cell types.
authors.affiliation: Laboratory for Cancer Medicine, University of Western Australia Center for Medical Research, Western Australian Institute for Medical Research, Perth, WA, Australia
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Webster
authors.forename: Keith M
authors.initials: KM
authors.lastname: Giles
authors.forename: Karina J
authors.initials: KJ
authors.lastname: Price
authors.forename: Priscilla M
authors.initials: PM
authors.lastname: Zhang
authors.forename: John S
authors.initials: JS
authors.lastname: Mattick
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Leedman
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D001483:Base Sequence; D015153:Blotting, Western; D002453:Cell Cycle; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D035683:MicroRNAs / Q000502:physiology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D020413:3' Untranslated Regions; D035683:MicroRNAs; D012333:RNA, Messenger; D008156:Luciferases; C512478:EGFR protein, human; D066246:ErbB Receptors; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3