title: Decreased expression of heparanase in glioblastoma multiforme.
abstract: OBJECTIVE
  The authors investigated the presence of endoglycosidase heparanase in human glioblastoma multiforme (GBM) and metastatic brain tumors as well as in healthy brain tissue to explore the relationship between the biological characteristics of GBM and the role of heparanase.
  
  
  METHODS
  Heparanase messenger (m)RNA was almost undetectable in GBMs in vivo, whereas it was frequently seen in metastatic brain tumors according to results of reverse transcription-polymerase chain reaction (RT-PCR). Immunohistochemical analysis of paraffin-embedded tissue sections showed that neoplastic cells in metastatic brain tumors, especially in cells that invaded blood vessels, exhibit intense heparanase immunoreactivity. Heparanase was present in two highly invasive glioma cell lines, U87MG and U251MG, in vitro. These cell lines did not have metastatic capability, which was tested in an experimental pulmonary metastases model in mice. The activity of heparanase in these cell lines was almost the same as that in the highly metastatic melanoma cell line B16-F1. After nude mice were inoculated with U87MG cells, however, heparanase was no longer detected in subcutaneous or intracerebral experimental glioma in vivo based on results of immunohistochemical analysis. According to results of real-time quantitative PCR, there was a 10-fold increase in heparanase mRNA in U87MG glioma cells in vitro compared with that in experimental U87MG glioma tissue in vivo in nude mice.
  
  
  CONCLUSIONS
  These results indicate that the expression of heparanase was downregulated in GBM in vivo, which rarely metastasizes to distant organs outside the central nervous system. Heparanase is not implicated in the invasiveness of GBM to surrounding healthy brain tissue in vivo.
authors.affiliation: Department of Neurosurgery, Fukuoka University School of Medicine, Fukuoka, Japan.
authors.forename: Yushi
authors.initials: Y
authors.lastname: Ueno
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Israel
authors.initials: I
authors.lastname: Vlodavsky
authors.forename: Iris
authors.initials: I
authors.lastname: Pecker
authors.forename: Kohichi
authors.initials: K
authors.lastname: Ohshima
authors.forename: Takeo
authors.initials: T
authors.lastname: Fukushima
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000201:enzymology*; D015536:Down-Regulation; D005260:Female; D005909:Glioblastoma / Q000201:enzymology*; D005966:Glucuronidase / Q000032:analysis* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000099175:Heparanase
chemical_list: D005966:Glucuronidase; D012333:RNA, Messenger; D000099175:Heparanase