gamma-Glutamyl transpeptidase expression in Ewing's sarcoma cells: up-regulation by interferons.
Biochem J
; 364(Pt 3): 719-24, 2002 Jun 15.
Article
em En
| MEDLINE
| ID: mdl-12049636
ABSTRACT
The genetic hallmark of Ewing's sarcoma family of tumours (ET) is the presence of the translocation t(11;22)(q24;q12), which creates the ET fusion gene, leading to cellular transformation. Five human gamma-glutamyl transpeptidase (gamma-GT) genes are located near the chromosomal translocation in ET. gamma-GT is a major enzyme involved in glutathione homoeostasis. Five human cell lines representative of primary or metastatic tumours were investigated to study whether gamma-GT alterations could occur at the chromosomal breaks and rearrangements in ET. As shown by enzymic assays and FACS analyses, all ET cell lines consistently expressed a functional gamma-GT which however did not discriminate steps of ET progression. As shown previously [Sancéau, Hiscott, Delattre and Wietzerbin (2000) Oncogene 19, 3372-3383], ET cells respond to the antiproliferative effects of interferons (IFNs) type I (alpha and beta) and to a much less degree to IFN type II (gamma). IFN-alpha and -beta arrested cells in the S-phase of the cell cycle. We found an enhancement of gamma-GT mRNA species with IFN-alpha and -beta by reverse transcriptase-PCR analyses. This is reflected by up-regulation of gamma-GT protein, which coincides with the increase in gamma-GT-specific enzymic activity. Similarly, IFNs up-regulate the levels of gamma-GT in another IFN-responsive B cell line. Whether this up-regulation of gamma-GT by IFNs is of physiological relevance to cell behaviour remains to be studied.
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Base de dados:
MEDLINE
Assunto principal:
Sarcoma de Ewing
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Neoplasias Ósseas
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Interferon Tipo I
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Regulação Enzimológica da Expressão Gênica
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Regulação Neoplásica da Expressão Gênica
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Interferon-alfa
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Gama-Glutamiltransferase
Limite:
Humans
Idioma:
En
Ano de publicação:
2002
Tipo de documento:
Article