title: Overexpression of the human major vault protein in gangliogliomas.
abstract: OBJECTIVE
  Recent evidence has been obtained that the major vault protein (MVP) may play a role in multidrug resistance (MDR). We investigated the expression and cellular localization of MVP in gangliogliomas (GGs), which are increasingly recognized causes of chronic pharmacoresistant epilepsy.
  
  
  METHODS
  Surgical tumor specimens (n = 30), as well as peritumoral and control brain tissues, were examined for the cellular distribution pattern of MVP with immunocytochemistry. Western blot analysis showed a consistent increase in MVP expression in GGs compared with that in control cortex.
  
  
  RESULTS
  In normal brain, MVP expression was below detection in glial and neuronal cells, and only low immunoreactivity (IR) levels were detected in blood vessels. MVP expression was observed in the neuronal component of 30 of 30 GGs and in a population of tumor glial cells. In the majority of the tumors, strong MVP IR was found in lesional vessels. Perilesional regions did not show increased staining in vessels or in neuronal and glial cells compared with normal cortex. However, expression of MVP was detected in the hippocampus in cases with dual pathology.
  
  
  CONCLUSIONS
  The increased expression of MVP in GGs is another example of an MDR-related protein that is upregulated in patients with refractory epilepsy. Further research is necessary to investigate whether it could play role in the mechanisms underlying drug resistance in chronic human epilepsy.
authors.affiliation: Department of (Neuro)Pathology, University of Amsterdam, Amsterdam, The Netherlands. e.aronica@amc.uva.nl
authors.forename: Eleonora
authors.initials: E
authors.lastname: Aronica
authors.forename: Jan A
authors.initials: JA
authors.lastname: Gorter
authors.forename: Erwin A
authors.initials: EA
authors.lastname: van Vliet
authors.forename: Wim G M
authors.initials: WG
authors.lastname: Spliet
authors.forename: Cees W M
authors.initials: CW
authors.lastname: van Veelen
authors.forename: Peter C
authors.initials: PC
authors.lastname: van Rijen
authors.forename: Sieger
authors.initials: S
authors.lastname: Leenstra
authors.forename: Marja D
authors.initials: MD
authors.lastname: Ramkema
authors.forename: George L
authors.initials: GL
authors.lastname: Scheffer
authors.forename: Rik J
authors.initials: RJ
authors.lastname: Scheper
authors.forename: Sanjay M
authors.initials: SM
authors.lastname: Sisodiya
authors.forename: Dirk
authors.initials: D
authors.lastname: Troost
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004827:Epilepsy / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D018303:Ganglioglioma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006624:Hippocampus / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D020394:Vault Ribonucleoprotein Particles / Q000096:biosynthesis* / Q000235:genetics; D000099187:Major Vault Protein
chemical_list: D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein