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Analysis of factors associated with the tumorigenic potential of 12 tumor clones derived from a single rat colon adenocarcinoma

✍ Scribed by R. Zennadi; L. Garrigue; S. Ringeard; A. Ménoret; P. Blanchardie; J. le Pendu


Publisher
John Wiley and Sons
Year
1992
Tongue
French
Weight
776 KB
Volume
52
Category
Article
ISSN
0020-7136

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✦ Synopsis


We analyzed several factors which could influence the immunogenicity of colon tumor cells, using a series of clones derived from a single chemically induced rat adenocarcinoma cell line. These clones display variable tumorigenic potential in syngeneic immunocompetent animals, and it has been established that in this model the tumorigenicity of the cells depends on their ability to escape immune surveillance. The results show an absence of relationship between tumorigenicity and expression of MHC-class-l antigens, cell adhesion to rat fibroblasts or fibroblast extracellular matrix. The secretion of latent and active TGFp I appeared to be quite variable from one clone to the other, but was unrelated to tumorigenicity. Unexpectedly, some regressive clones produced elevated levels of this cytokine, suggesting that in this model, spontaneous secretion of TGFp I is not sufficient to impair the immune system of the host. In contrast, the more tumorigenic clones were more resistant than less tumorigenic ones to cytotoxicity mediated by NK or LAK cells. They also showed arrest of cell proliferation after reaching confluence, something not observed in the less tumorigenic clones. Finally, the strongest relationship with tumorigenicity was found for expression of blood-group carbohydrate antigens. Increased expression of blood-group-H antigen and, conversely, decreased expression of p-galactoside precursors of this antigen correlated with increased tumorigenicity.