Heme oxygenase (HO) isoforms in experimental C6 glioma: an immunocytochemical study.
Abstract Because of their potential to regulate tumoural blood flow and interactions with nitric oxide the expression of the type 1 and 2 isoforms of heme oxygenase (HO-1 and HO-2) were evaluated in implanted C6 striatal gliomas. Immunocytochemistry using antibodies specific for HO-1 and HO-2 were used in 20 C6 glioma tumours. The bulk of the tumour parenchyma and endothelium was negative for both HO isoforms. Isolated, but weak staining for HO-1 was seen in most tumours with focally increased expression in perinecrotic regions. Cells morphologically resembling macrophages stained with both HO-1 and HO-2, but were not numerous. These findings suggest that carbon monoxide, unlike nitric oxide, does not have a major role in regulating tumoural blood flow in this experimental glioma model. These findings once again demonstrate the differences between human malignant glioma and experimental implantation glioma models.
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Department of Clinical Neurosciences and Pathology, University of Edinburgh, Western General Hospital, UK.
Bell
H S
HS
Yamaguchi
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Wharton
S B
SB
Whittle
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IR
D000818:Animals; D005910:Glioma / Q000098:blood supply / Q000201:enzymology* / Q000648:ultrastructure; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism*; D051547:Heme Oxygenase-1; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008565:Membrane Proteins; D009363:Neoplasm Proteins / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D014407:Tumor Cells, Cultured
D008565:Membrane Proteins; D009363:Neoplasm Proteins; D009569:Nitric Oxide; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1