Overexpression of the human major vault protein in gangliogliomas.
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.
Aronica
Eleonora
E
Department of (Neuro)Pathology, University of Amsterdam, Amsterdam, The Netherlands. e.aronica@amc.uva.nl
Gorter
Jan A
JA
van Vliet
Erwin A
EA
Spliet
Wim G M
WG
van Veelen
Cees W M
CW
van Rijen
Peter C
PC
Leenstra
Sieger
S
Ramkema
Marja D
MD
Scheffer
George L
GL
Scheper
Rik J
RJ
Sisodiya
Sanjay M
SM
Troost
Dirk
D
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
D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein