Control of apoptosis in Epstein Barr virus-positive nasopharyngeal carcinoma cells: opposite effects of CD95 and CD40 stimulation.
Cancer Res
; 59(4): 924-30, 1999 Feb 15.
Article
em En
| MEDLINE
| ID: mdl-10029086
ABSTRACT
The expression and function of CD95 and CD40 were investigated in malignant cells from EBV-positive undifferentiated nasopharyngeal carcinomas (NPCs). Large amounts of CD95 and CD40 expression were detected in 15 of 16 EBV-positive NPC specimens. In contrast, CD95 was not detected in two biopsies from patients with EBV-negative differentiated NPCs. We tested whether the CD95 apoptotic pathway was functional in NPC cells by treating two EBV-positive NPC tumor lines in vitro with a CD95 agonist. In both cases, NPC cells were extremely susceptible to CD95-mediated apoptosis, despite strong constitutive expression of Bcl-x. Combined CD40 and CD95 stimulation was used to investigate the possible anti-apoptotic activity mediated by CD40. The CD40 receptor was activated by incubating NPC cells with murine L cells producing CD154, the CD40 ligand. This treatment resulted in a strong inhibition of CD95-related cytotoxicity. Such an anti-apoptotic effect of CD40 is well known for B lymphocytes, but has not previously been reported for epithelial cells. These data suggest that NPC tumor-infiltrating lymphocytes, which often produce the CD40 ligand in situ, may increase the survival of malignant cells, thereby enhancing tumor growth in patients.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Nasofaríngeas
/
Apoptose
/
Herpesvirus Humano 4
/
Receptor fas
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Antígenos CD40
Limite:
Adolescent
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Female
/
Humans
Idioma:
En
Revista:
Cancer Res
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
França