Determination human brain tumor marker gene carbonic anhydrase 9 (CA9) gene expression in different type of brain tumor cells

The hypoxia-inducible enzyme carbonic anhydrase IX (CA-IX) is considered as a surrogate marker of tumor hypoxia, prognosis indicator and a potential the expression pattern of the human tumor hypoxia marker gene CA-IX protein, CA9-mRNA and hypoxia-inducible factor-In (HIF-1α) protein levels in GaMG cells exposed to in vitro hypoxia (1, 6 or 24 h at 5%, 1 % or 0.1 % 02). All cell lines displayed a strong hypoxic induction of CA9-mRNA in response to prolonged severe hypoxia with cell-line specific patterns at moderate to mild hypoxia and shorter treatment times. In GaMG cell lines, a marked induction of CA-IX protein in response to severe hypoxia was seen. CA-IX over expression was paralleled by the results for HIF-1α protein. CA-IX expression pattern in human malignant glioblastoma cells (GBM) resulted from low oxygen concentrations or constitutive, oncogene-related, over expression is considered prognostically relevant.