title: Relative expression of mRNAS coding for glutaminase isoforms in CNS tissues and CNS tumors.
abstract: Glutaminase (GA) in mammalian tissues occurs in three isoforms: LGA (liver-type), KGA (kidney-type) and GAC (a KGA variant). Our previous study showed that human malignant gliomas (WHO grades III and IV) lack expression of LGA mRNA but are enriched in GAC mRNA relative to KGA mRNA. Here we analyzed the expression of mRNAs coding for the three isoforms in the biopsy material derived from other central nervous system tumors of WHO grades I-III. Non-neoplastic resective epileptic surgery samples served as control, as did cultured rat astrocytes and neurons. The GAC mRNA/KGA mRNA expression ratio was as a rule higher in the neoplastic than in control tissues, irrespective of the cell type dominating in the tumor or tumor malignancy. LGA mRNA expression was relatively very low in cultured astrocytes, and very low to absent in astrocytoma pilocyticum, ependymoma and subependymal giant cell astrocytoma (SEGA), tumors of astrocytic origin. LGA mRNA expression was almost as high as that of KGA and GAC mRNA in cultured neurons and epileptic surgery samples which were enriched in neurons. LGA mRNA was also relatively high in ganglioglioma which contains a discernable proportion of neuronal cells, and in oligodendroglioma. The results show that low expression of LGA mRNA is a feature common to normal astrocytes and astroglia-derived tumor cells or ependymomas and can be considered as a cell-type, rather than a malignancy marker.
authors.affiliation: Department of Neurotoxicology, M. Mossakowski Medical Research Center, Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Szeliga
authors.forename: Ewa
authors.initials: E
authors.lastname: Matyja
authors.forename: Marta
authors.initials: M
authors.lastname: Obara
authors.forename: Wiesława
authors.initials: W
authors.lastname: Grajkowska
authors.forename: Tomasz
authors.initials: T
authors.lastname: Czernicki
authors.forename: Jan
authors.initials: J
authors.lastname: Albrecht
mesh_terms: D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D002490:Central Nervous System / Q000201:enzymology*; D016543:Central Nervous System Neoplasms / Q000201:enzymology*; D002648:Child; D017931:DNA Primers; D005972:Glutaminase / Q000235:genetics*; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; D005972:Glutaminase