TITLE:
Carbonic anhydrase VII–a potential prognostic marker in gliomas
AUTHORS:
Fatemeh Bootorabi, Joonas Haapasalo, Elona Smith, Hannu Haapasalo, Seppo Parkkila
KEYWORDS:
Astrocytoma; Brain; Cancer;
Carbonic Anhydrase; Glioblastoma; Glioma;
Oligodendroglioma; pH
JOURNAL NAME:
Health,
Vol.3 No.1,
January
29,
2011
ABSTRACT: Carbonic anhydrase VII (CA VII) is a cytosolic enzyme expressed in several organs, including the human brain, but it has not been investigated earlier in any tumors. We designed the present study to evaluate CA VII expression in a cohort of human diffuse astrocytomas, mixed oligoastrocytomas and oligodendrogliomas. CA VII immunostaining was correlated to clinico-pathologic findings, survival data, and expres-sion of other molecular factors, including Ki-67, p53 protein and epidermal growth factor receptor. CA VII-positive staining was observed in 94% of astrocytomas and 85% of oligodendrogliomas. In the tumor specimens, strong positive areas were often located in close proximity to necrosis. The CA VII immunoreactivity showed positive correlation with tumor malignancy grades of astrocytomas (p = 0.02, chi-square test). In all tumor categories, CA VII-positive staining was often seen in the en-dothelial cells of neovessels in addition to the tumor cells. CA VII intensity showed no significant association with p53 nor did it correlate with the amplification of epidermal growth factor receptor (analyzed only in astrocytomas) or cell proliferation. Our present results show that CA VII may act as a useful biomarker in histopathologic diagnostics of gliomas. The high expression of CA VII in the tumor cells and endothelium suggests important roles for the enzyme in tumor metabolism. The results also led us to conclude that CA VII might serve as a marker of poor prognosis in diffuse astrocytomas.