Osamu Tachibana

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Glioblastoma multiforme, the most malignant human brain tumor, may develop de novo (primary glioblastoma) or through progression from low-grade or anaplastic astrocytoma (secondary glioblastoma). We present further evidence that primary and secondary glioblastomas constitute distinct disease entities which develop through the acquisition of different(More)
Mutations of the p53 tumor suppressor gene are a genetic hallmark of human astrocytic neoplasms, but their predictive role in glioma progression is still poorly understood. We analyzed 144 biopsies from 67 patients with recurrent astrocytoma by single-strand conformation polymorphism and direct DNA sequencing. We found that 46 of 67 patients (69%) had a p53(More)
The human UDP-glucuronosyltransferase, UGT1A9, catalyses glucuronidations of various endobiotics and xenobiotics. In the present study, all exons, exon-intron junctions, and the 5'-flanking region (-273 bp) of the UGT1A9 gene in a Japanese subject were sequenced. One base insertion of thymidine in a promoter region of the UGT1A9 gene resulting in A(T)10AT(More)
Fas/APO-1 (CD95) is a cell surface receptor that mediates apoptosis when it reacts with Fas ligand (FasL) or Fas antibody. We previously reported that Fas expression is predominantly induced in perinecrotic glioma cells, suggesting that Fas induction is associated with apoptosis and necrosis formation, a histological hallmark of glioblastomas. In this(More)
Fas/APO-1 (CD95)-mediated apoptosis is one of the major mechanisms of programmed cell death. We have previously shown by reverse transcriptase-polymerase chain reaction that Fas is frequently expressed in malignant gliomas [Tachibana et al. (1995) Cancer Res 55: 5528–5530]. In this study, we assessed Fas expression in astrocytomas using a polyclonal(More)
The presence of gemistocytes in low-grade astrocytomas is regarded as a sign of poor prognosis because the majority of gemistocytic astrocytomas rapidly progress to anaplastic astrocytoma or glioblastoma. To elucidate the role of gemistocytes in astrocytoma progression, we assessed the fraction of neoplastic gemistocytes, bcl-2 expression, p53 mutations,(More)
Fas/APO-1 (CD95) is an apoptosis-signaling receptor molecule on the surface of cells. To investigate the possible role of Fas during malignant transformation of glial cells, we analyzed the expression of Fas mRNA by reverse transcription-PCR in human astrocytic brain tumors. Expression was found in 1 of 4 (25%) juvenile pilocytic astrocytomas (WHO grade I),(More)
Glioblastoma multiforme is a rare neoplasm in children and is often located infratentorially, particularly in the brainstem: Pediatric glioblastomas arise frequently (here 60%) outside the cerebral hemispheres. We investigated 20 pediatric glioblastomas for mutational inactivation of the p53 tumor suppressor gene, loss of p16 protein expression and(More)
Glioblastomas may develop rapidly without clinical and histopathological evidence of a less malignant precursor lesion (de novo or primary glioblastoma) or through progression from low-grade or anaplastic astrocytoma (secondary glioblastoma). Primary glioblastomas typically show overexpression of EGFR, but rarely p53 mutations, while secondary glioblastomas(More)
The Fas antigen (Fas/Apo-1/CD95) is a cell surface receptor protein that mediates apoptosis-inducing signals and plays an important role in the immune system. In the central nervous system, during the period of naturally occurring cell death many neurons appear to die by apoptosis. We investigated the involvement of Fas in these events. The expression of(More)