title: Amphiregulin antisense oligonucleotide inhibits the growth of T3M4 human pancreatic cancer cells and sensitizes the cells to EGF receptor-targeted therapy.
abstract: Human pancreatic cancers overexpress the epidermal growth factor (EGF) receptor (EGFR) and all 5 ligands that bind to this receptor, including amphiregulin. It is not known, however, whether amphiregulin contributes in an autocrine manner to enhance pancreatic cancer cell growth. Therefore, we used an amphiregulin antisense oligonucleotide (AR-AS) to suppress amphiregulin expression in T3M4 human pancreatic cancer cells. These cells express high levels of EGFR and amphiregulin. AR-AS abolished amphiregulin immunoreactivity in T3M4 cells, decreased amphiregulin release into the medium and inhibited cell growth in a dose-dependent manner. Exogenous amphiregulin reversed AR-AS-mediated growth inhibition. A random oligonucleotide (AR-R) did not alter either cell growth or cellular amphiregulin immunoreactivity. AR-AS also increased cellular EGFR protein levels and enhanced the growth-inhibitory actions of TP40, a chimeric protein consisting of transforming growth factor-alpha coupled to Pseudomonas exotoxin that internalizes into cells via EGFR. These findings indicate that there is an important EGFR/ amphiregulin autocrine loop in T3M4 cells and raise the possibility that modalities aimed at abrogating amphiregulin action may prove useful in pancreatic cancer, especially when used in conjunction with EGFR-targeted therapy.
authors.affiliation: Department of Medicine, University of California, Irvine 92697, USA.
authors.forename: H
authors.initials: H
authors.lastname: Funatomi
authors.forename: J
authors.initials: J
authors.lastname: Itakura
authors.forename: T
authors.initials: T
authors.lastname: Ishiwata
authors.forename: I
authors.initials: I
authors.lastname: Pastan
authors.forename: S A
authors.initials: SA
authors.lastname: Thompson
authors.forename: G R
authors.initials: GR
authors.lastname: Johnson
authors.forename: M
authors.initials: M
authors.lastname: Korc
mesh_terms: D000595:Amino Acid Sequence; D066258:Amphiregulin; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D066255:EGF Family of Proteins; D066246:ErbB Receptors / Q000187:drug effects*; D005098:Exotoxins / Q000378:metabolism / Q000494:pharmacology; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006133:Growth Substances / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000473:pathology*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016211:Transforming Growth Factor alpha / Q000378:metabolism / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: C587848:AREG protein, human; D066258:Amphiregulin; D000970:Antineoplastic Agents; D066255:EGF Family of Proteins; D005098:Exotoxins; D006023:Glycoproteins; D006133:Growth Substances; D036341:Intercellular Signaling Peptides and Proteins; D016376:Oligonucleotides, Antisense; D011993:Recombinant Fusion Proteins; D016211:Transforming Growth Factor alpha; C083452:transforming growth factor alpha-Pseudomonas exotoxin A (40); D066246:ErbB Receptors