title: Secretion of gastrin-releasing peptide by retroperitoneal tumors.
abstract: OBJECTIVE
  Gastrin-releasing peptide (GRP) is a neuropeptide with growth factor activity in vitro for a variety of tumors including neuroblastoma. If GRP is secreted by neuroblastomas, its detection in serum might be an excellent way to both diagnose and monitor this tumor in patients.
  
  
  METHODS
  Small portions of resected tumor specimens were maintained in tissue culture as tumor explants for 24 hours. The tumors included: 3 ganglioneuromas, 1 neuroblastoma, 1 primitive neuroectodermal tumor, 1 Wilms' tumor, 1 rhabdoid tumor, and 1 benign brachial plexus tumor. Control flasks were maintained simultaneously under identical conditions. After 24 hours of incubation, the tumor-conditioned media and the control media were assayed in duplicate for [GRP] using a radioimmunoassay.
  
  
  RESULTS
  All the conditioned media from the benign tumors contained < 25 pg/mL net GRP, whereas all the malignant tumor-conditioned media contained > or = 45 pg/mL (P = 0.003).
  
  
  CONCLUSIONS
  These data suggest that GRP is secreted by pediatric retroperitoneal tumors and that the amount secreted varies directly with the degree of malignancy of the tumor. This study suggests that GRP may be a candidate tumor marker for pediatric retroperitoneal tumors.
authors.affiliation: Department of Surgery, Children's Hospital, Seattle, Washington 98105, USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Sawin
authors.forename: J
authors.initials: J
authors.lastname: Brockenbrough
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D002471:Cell Transformation, Neoplastic / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D002648:Child; D017077:Culture Media, Conditioned; D019886:Gastrin-Releasing Peptide; D005768:Gastrointestinal Hormones / Q000378:metabolism*; D006801:Humans; D010455:Peptides / Q000378:metabolism*; D012186:Retroperitoneal Neoplasms / Q000175:diagnosis / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D017077:Culture Media, Conditioned; D005768:Gastrointestinal Hormones; D010455:Peptides; D019886:Gastrin-Releasing Peptide