title: The expression of ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (E-NPP1) is correlated with astrocytic tumor grade.
abstract: OBJECTIVE
  Astrocytic brain tumors are subdivided in four grades. The most aggressive and invasive one is grade IV or glioblastoma multiforme (GBM). Ecto-nucleotide pyrophosphatase/phosphodiesterase-1 (E-NPP1), a membrane-bound enzyme, is involved in many cellular processes such as modulation of purinergic signalling, nucleotide recycling, regulation of extracellular pyrophosphate levels and stimulation of cell motility. In this study, the use of anti-NPP1 antibody in the determination of astrocytic tumor grade is evaluated.
  
  
  METHODS
  Paraffin-embedded surgical specimens from 41 primary human astrocytic brain tumors (grade I=2; grade II=10; grade III=9; grade IV=20) and 5 control samples are immunostained against NPP1 and glial fibrillary acid protein an astrocytic marker.
  
  
  RESULTS
  In this communication, we report the expression of NPP1 in human astrocytic brain tumors. No expression could be detected in control tissue. We observed a remarkable up regulated expression of NPP1 in GBM. Taking the latter as 100%, grade I has a relative NPP1 staining of 7%, whereas grade II and III have a similar NPP1 expression level of 53% and 47% respectively.
  
  
  CONCLUSIONS
  A correlation is found between the up-regulated expression of NPP1 and the grade of the astrocytic tumor. Further investigation of NPP1 expression, especially in GBM, is necessary to determine the role of NPP1 in astrocytic brain tumor progression.
authors.affiliation: Department of Biomedical Science, Cellular Biochemistry, Campus Drie Eiken, University of Antwerp, Belgium.
authors.forename: Indra
authors.initials: I
authors.lastname: Aerts
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Martin
authors.forename: Peter Paul
authors.initials: PP
authors.lastname: De Deyn
authors.forename: Chris
authors.initials: C
authors.lastname: Van Ginniken
authors.forename: Xaveer
authors.initials: X
authors.lastname: Van Ostade
authors.forename: Mark
authors.initials: M
authors.lastname: Kockx
authors.forename: Guido
authors.initials: G
authors.lastname: Dua
authors.forename: Herman
authors.initials: H
authors.lastname: Slegers
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001254:Astrocytoma / Q000235:genetics* / Q000473:pathology*; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology*; D002452:Cell Count; D045744:Cell Line, Tumor; D004396:Coloring Agents; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005909:Glioblastoma / Q000235:genetics* / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D016612:Paraffin Embedding; D010727:Phosphoric Diester Hydrolases / Q000096:biosynthesis / Q000235:genetics*; D011755:Pyrophosphatases / Q000096:biosynthesis / Q000235:genetics*; D051381:Rats; D016707:Tissue Fixation
chemical_list: D004396:Coloring Agents; D005904:Glial Fibrillary Acidic Protein; D010727:Phosphoric Diester Hydrolases; C065962:ectonucleotide pyrophosphatase phosphodiesterase 1; D011755:Pyrophosphatases