title: Malignant effusions contain lysophosphatidic acid (LPA)-like activity.
abstract: BACKGROUND
  Lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) are bioactive phospholipids with mitogenic and growth factor-like activities that act via specific cell-surface receptors present in many normal and transformed cell types. LPA has recently been implicated as a growth factor present in ascites of ovarian cancer patients. The presence of LPA-like activity and the hypothesis that levels of this bioactivity in effusions of ovarian cancer patients are higher than those in effusions of other cancer patients was studied.
  
  
  METHODS
  A neurite retraction bioassay in a neuroblastoma cell line previously developed for in vitro detection of LPA activity on cell lines was employed and bioactivity was expressed in virtual LPA-equivalent levels. LPA-equivalent levels were tested in effusions of 62 patients with a range of malignancies, including 13 ovarian cancer patients. Biochemical and clinical parameters were evaluated for correlations with LPA-equivalent levels.
  
  
  RESULTS
  Average LPA-equivalent levels were 50.2 microns (range 5.4-200) for all patients, and 94.5 microns (range 15-200) for ovarian cancer patients (P = 0.004). There were no additional independent significant correlations between LPA-equivalent levels in effusions and a range of other biochemical and clinical characteristics.
  
  
  CONCLUSIONS
  These data suggest a role for LPA-like lipids in the peritoneal spread of ovarian cancer and possibly that of other predominantly intraperitoneal malignancies.
authors.affiliation: Department of Medical Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands. annie@nki.nl
authors.forename: A M
authors.initials: AM
authors.lastname: Westermann
authors.forename: E
authors.initials: E
authors.lastname: Havik
authors.forename: F R
authors.initials: FR
authors.lastname: Postma
authors.forename: J H
authors.initials: JH
authors.lastname: Beijnen
authors.forename: O
authors.initials: O
authors.lastname: Dalesio
authors.forename: W H
authors.initials: WH
authors.lastname: Moolenaar
authors.forename: S
authors.initials: S
authors.lastname: Rodenhuis
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000556:secondary; D001202:Ascitic Fluid / Q000737:chemistry* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism; D005260:Female; D006258:Head and Neck Neoplasms / Q000378:metabolism; D006801:Humans; D007680:Kidney Neoplasms / Q000378:metabolism; D008113:Liver Neoplasms / Q000556:secondary; D008175:Lung Neoplasms / Q000378:metabolism; D008228:Lymphoma, Non-Hodgkin / Q000378:metabolism; D008246:Lysophospholipids / Q000032:analysis*; D009382:Neoplasms, Unknown Primary / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000378:metabolism* / Q000473:pathology; D016066:Pleural Effusion, Malignant / Q000737:chemistry*; D011379:Prognosis; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
chemical_list: D014408:Biomarkers, Tumor; D008246:Lysophospholipids