title: Expression of TAP73 and DeltaNP73 in malignant gliomas.
abstract: The p73 gene is able to encode transcriptionaly active TAp73, as well as a dominant-negatively acting DeltaNp73 transcript isoforms. We studied differential expression of these forms in normal brain as well as glial tumors, by semiquantitative RT-PCR. The expression of p73 was low or undetectable in normal brain tissues. Most of the tumors and non-tumor brain tissues also lacked significant expression of p73 in patients with low-grade astrocytomas. In contrast, most high-grade glial tumors displayed strong up-regulation of TAp73, whereas only a few displayed DeltaNp73 expression. These aberrations may reflect the inactivation of retinoblastoma pathway in these tumors which result in the activation of E2F transcription factors, since TAp73 is a known target of E2F1 gene. The study of TAp73 expression in brain tumors may serve as a means to evaluate the retinoblastoma pathway-dependent tumor progression.
authors.affiliation: Department of Molecular Biology and Genetics, Bilkent University, 06800 Ankara, Turkey.
authors.forename: Hasan
authors.initials: H
authors.lastname: Ugur
authors.forename: A E
authors.initials: AE
authors.lastname: Sayan
authors.forename: Sukru O
authors.initials: SO
authors.lastname: Ozdamar
authors.forename: Yucel
authors.initials: Y
authors.lastname: Kanpolat
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ozturk
mesh_terms: D001921:Brain / Q000378:metabolism / Q000473:pathology; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D005799:Genes, Dominant; D016147:Genes, Tumor Suppressor; D005910:Glioma / Q000235:genetics*; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017384:Sequence Deletion; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins; D015854:Up-Regulation
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012334:RNA, Neoplasm; C000606460:TP73 protein, human; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins; C000606369:delta Np73 protein, human