Estudo da expressão de citocinas e componentes de apoptose no tumor de Walker 256, comparação entre a linhagem A e variant Ar / Study of cytokine gene expression and components of apoptosis in Walker 256, a comparison of variants A (Aggressive) and AR (Regressive)

AUTOR(ES)

Ana Paula de Almeida Salles Perroud

DATA DE PUBLICAÇÃO

2005

RESUMO

Two variants of this Walker 256 tumor have been previously reported as Walker 256 A and variant Ar. The variant A is more aggressive and can induce systemic effects as anorexia, sodium and water retention, followed by weight loss and death. The mechanisms involved in enhancing tumor regression and progression in this model is still incompletely understood. In the present study, spleen cells and tumor cells from animals inoculated with variants A and AR, were isolated to investigate the TGF-?, IL-12, IFN-?, TNF-? gene expression, components of apoptosis and relationship with anemia, weight of animals, weight of spleen, height of tumor and osmotic fragility compared with controls inoculated with Ringer Lactate. Results demonstrate that the group inoculated with variant A compared with variant Ar, shows high levels of TGF-? gene expression in both tumor tissue and spleen cells, no expression of IFN-? and a progressive and higher levels of IL-12 in tumor tissue without inflammatory infiltrate. These results suggest that the aggressively of variant A is relate to cytokine modulation, facilitating the growth and escape of tumor cells. Furthermore, IL-12 seems to be constitutively expressed in both tumor lineage A and AR. The mRNA expression of Bcl-2 was progressive and there is no expression of Fas on tumoral cells of group A. These results demonstrate that on the lineage A the immunogenicity occurs by others mechanisms. The expression of cytokines and components of apoptosis can explain the differences of lineages A and AR.

ASSUNTO(S)

citocinas interferon alfa interferon alpha transforming growth factor-beta tumor necrosis factor-alpha apoptosis fator de necrose de tumoral alfa tumor walker 256 interleukin-12 interleucina-12 cytokines fator transformador de crescimento beta tumor walker 256 apoptose

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