title: The Ewing tumor family of peripheral primitive neuroectodermal tumors expresses human gastrin-releasing peptide.
abstract: The Ewing tumor family of peripheral primitive neuroectodermal tumors (pPNETs) are characterized by chromosomal translocations leading to EWS-ETS gene fusions. These hybrid genes express chimeric proteins that are thought to act as aberrant transcription factors. We therefore used differential display-PCR to compare gene expression patterns in pPNET cell lines with those of other small round cell tumors (SRCTs) of childhood. This technique detected differential expression of sequences corresponding to human gastrin-releasing peptide (GRP) in pPNET cell lines but not in other SRCT cell lines. Subsequent Northern and reverse transcription-PCR analysis of SRCT cell lines confirmed GRP positivity in all pPNET lines tested. Of primary tumors tested by reverse transcription-PCR, GRP expression was found in 7 (44%) of 16 pPNETs but in no other primary SRCTs examined. Expression of the GRP receptor gene was demonstrable in 55% of pPNET cell lines and 25% of primary pPNET tumors but also in several other SRCTs. Radioimmunoassays and immunohistochemistry confirmed expression of bioactive GRP peptide in pPNET cell lines and primary tumors, respectively. Moreover, in vitro growth of a pPNET cell line was slowed by treatment with a GRP receptor antagonist and accelerated by a GRP receptor agonist. GRP is a known autocrine growth factor in small cell lung cancer and other neuroendocrine tumors. Its expression in pPNETs provides further evidence for a neuroectodermal histogenesis of these tumors and suggests that autocrine growth of this family of tumors may be at least partially regulated by GRP.
authors.affiliation: Department of Pathology, British Columbia's Children's Hospital, Vancouver, Canada.
authors.forename: E R
authors.initials: ER
authors.lastname: Lawlor
authors.forename: J F
authors.initials: JF
authors.lastname: Lim
authors.forename: W
authors.initials: W
authors.lastname: Tao
authors.forename: C
authors.initials: C
authors.lastname: Poremba
authors.forename: C J
authors.initials: CJ
authors.lastname: Chow
authors.forename: I V
authors.initials: IV
authors.lastname: Kalousek
authors.forename: H
authors.initials: H
authors.lastname: Kovar
authors.forename: T J
authors.initials: TJ
authors.lastname: MacDonald
authors.forename: P H
authors.initials: PH
authors.lastname: Sorensen
mesh_terms: D019677:Artificial Gene Fusion; D001483:Base Sequence; D001859:Bone Neoplasms / Q000235:genetics; D018288:Carcinoma, Small Cell / Q000235:genetics; D003001:Cloning, Molecular; D019886:Gastrin-Releasing Peptide / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000235:genetics*; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D018004:Receptors, Bombesin / Q000096:biosynthesis / Q000235:genetics; D012512:Sarcoma, Ewing / Q000235:genetics; D018228:Sarcoma, Small Cell / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D010455:Peptides; D011498:Protein Precursors; D018004:Receptors, Bombesin; C047897:gastrin-releasing peptide precursor; D019886:Gastrin-Releasing Peptide