Carbonic anhydrase IX in oligodendroglial brain tumors.
BACKGROUND
Carbonic anhydrase IX is a hypoxia-induced enzyme that has many biologically important functions, including its role in cell adhesion and invasion.


METHODS
This study was set out to investigate the role of CA IX in a series of 86 oligodendroglial brain tumors (71 primary and 15 recurrent; 48 pure oligodendrogliomas and 40 mixed oligoastrocytomas).


RESULTS
80% of the tumors showed CA IX expression by immunohistochemistry. Tumors with moderate or strong CA IX expression had decreased level of cell proliferation compared to weak or no CA IX expression (median 2.9 vs. 5.8, p = 0.015). CA IX correlated with two antioxidative enzymes, manganese superoxide dismutase (MnSOD) and regulatory gammaglutamylcysteine synthetase (GLCL-R): CA IX expression was significantly higher in MnSOD-positive tumors (p = 0.008) and decreased in GLCL-R-positive tumors (p = 0.044). In Cox multivariate analysis CA IX expression, patient age and histological component (pure oligodendroglioma vs. mixed oligoastrocytoma) showed independent prognostic values (p = 0.009, p = 0.003 and p = 0.022, respectively), CA IX positivity predicting poorer outcome.


CONCLUSIONS
CA IX was proved to be an independent prognostic indicator in oligodendroglial brain tumors, and it also correlates reversely with cell proliferation. It may have a role in the biology of oligodendrogliomas, and most interestingly, as it is mainly expressed in tumor tissue, CA IX could serve as a target molecule for anticancer treatments.
Järvelä
Sally
S
Department of Pathology, Centre for Laboratory Medicine, Tampere University Hospital, Tampere, Finland. sally.jarvela@sci.fi
Parkkila
Seppo
S
Bragge
Helena
H
Kähkönen
Marketta
M
Parkkila
Anna-Kaisa
AK
Soini
Ylermi
Y
Pastorekova
Silvia
S
Pastorek
Jaromir
J
Haapasalo
Hannu
H
D000328:Adult; D000951:Antigens, Neoplasm / Q000378:metabolism*; D001932:Brain Neoplasms / Q000201:enzymology* / Q000473:pathology; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases / Q000378:metabolism*; D049109:Cell Proliferation; D005500:Follow-Up Studies; D006801:Humans; D009837:Oligodendroglioma / Q000201:enzymology* / Q000473:pathology; D015996:Survival Rate
D000951:Antigens, Neoplasm; C089226:CA9 protein, human; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases