c-Myc and EBV-LMP1: two opposing regulators of the HLA class I antigen presentation machinery in epithelial cells.
Br J Cancer
; 106(12): 1980-8, 2012 Jun 05.
Article
em En
| MEDLINE
| ID: mdl-22588558
ABSTRACT
BACKGROUND:
Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) up-regulates the human leukocyte antigen (HLA) class I antigen presentation machinery (APM). This appears counterintuitive with immune evasion in EBV-associated tumours like nasopharyngeal carcinoma (NPC).METHODS:
Latent membrane protein 1-transfected epithelial cell lines were used as a model system to study the impact of LMP1 and c-Myc on HLA class I components. The expression of components of the HLA class I APM, c-Myc and Ki-67 was analysed in LMP1+ and LMP1- NPC by immunohistochemistry.RESULTS:
In epithelial cells, LMP1 up-regulated HLA class I APM. This effect could be counteracted by c-Myc, which itself was up-regulated by LMP1 apparently through IL6 induction and Jak3/STAT3 activation. Studies of NPC biopsies revealed down-regulation of HLA class I APM expression. No difference was observed between LMP1+ and LMP1- NPC. However, expression of Ki-67 and c-Myc were up-regulated in LMP1+ tumours.CONCLUSION:
These findings raise the possibility that c-Myc activation in NPC might antagonise the effect of LMP1 on HLA class I expression thus contributing to immune escape of tumour cells.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Antígenos de Histocompatibilidade Classe I
/
Proteínas da Matriz Viral
/
Neoplasias Nasofaríngeas
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Proteínas Proto-Oncogênicas c-myc
/
Apresentação de Antígeno
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article