Immunoprevention of chemical carcinogenesis through early recognition of oncogene mutations.
J Immunol
; 194(6): 2683-95, 2015 Mar 15.
Article
em En
| MEDLINE
| ID: mdl-25694611
ABSTRACT
Prevention of tumors induced by environmental carcinogens has not been achieved. Skin tumors produced by polyaromatic hydrocarbons, such as 7,12-dimethylbenz(a)anthracene (DMBA), often harbor an H-ras point mutation, suggesting that it is a poor target for early immunosurveillance. The application of pyrosequencing and allele-specific PCR techniques established that mutations in the genome and expression of the Mut H-ras gene could be detected as early as 1 d after DMBA application. Further, DMBA sensitization raised Mut H-ras epitope-specific CTLs capable of eliminating Mut H-ras(+) preneoplastic skin cells, demonstrating that immunosurveillance is normally induced but may be ineffective owing to insufficient effector pool size and/or immunosuppression. To test whether selective pre-expansion of CD8 T cells with specificity for the single Mut H-ras epitope was sufficient for tumor prevention, MHC class I epitope-focused lentivector-infected dendritic cell- and DNA-based vaccines were designed to bias toward CTL rather than regulatory T cell induction. Mut H-ras, but not wild-type H-ras, epitope-focused vaccination generated specific CTLs and inhibited DMBA-induced tumor initiation, growth, and progression in preventative and therapeutic settings. Transferred Mut H-ras-specific effectors induced rapid tumor regression, overcoming established tumor suppression in tumor-bearing mice. These studies support further evaluation of oncogenic mutations for their potential to act as early tumor-specific, immunogenic epitopes in expanding relevant immunosurveillance effectors to block tumor formation, rather than treating established tumors.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Cutâneas
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Genes ras
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Mutação Puntual
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Vacinas Anticâncer
Limite:
Animals
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Female
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Humans
Idioma:
En
Revista:
J Immunol
Ano de publicação:
2015
Tipo de documento:
Article