Data/hora: 12/06/2024 15:08:13

Provedor de dados: | 56
País: | Brazil
Título: | Evaluation of an anti-carcinoembryonic monoclonal antibody suitable for immunoscintigraphy
Autores: | Moraes,D.W.; Lima,E.N.P.; Prado,I.B.; Carneiro,C.R.W.
Data: | 1999-08-01
Ano: | 1999
Palavras-chave: | Monoclonal antibody; Carcinoembryonic antigen; Colorectal carcinoma; Immunoscintigraphy; Technetium-99m.
Resumo: | An anti-carcinoembryonic antigen (CEA) monoclonal antibody (mAb 6D1.1) was evaluated in vitro and in vivo to determine its suitability as a tracer for immunoscintigraphy of colorectal carcinomas. Determination of mAb affinity for CEA showed a constant of association of 0.63 ± 0.11 x 109 M-1. Binding of technetium-99m (99mTc)-6D1.1, labeled by a direct method, to human cultured lineages was highly specific. Binding to only CEA-positive LS-174T cells resulted in a saturable curve inhibited by pre-incubation with unlabeled mAb. No binding at all was observed for the human lineages MeWo (melanoma) or ZR75-30 (breast carcinoma), neither of them expressing CEA cells. Intravenous injection of 99mTc-6D1.1 into nude mice xenografted with human LS-174T tumors resulted in planar images of excellent quality. Localization of an irrelevant mAb labeled with either 99mTc or iodine-125 was never observed in tumor masses. Biodistribution studies on excised tumoral tissue showed retention of 28.48% of the injected dose per gram of LS-174T tumor. The tumor-to-blood ratio was 3.46. The same analysis performed on the other three human xenografted tumors studied demonstrated that only the CEA-producing HT-29 (colorectal adenocarcinoma) retained 99mTc-6D1.1 while the other two (ZR75-30 and MeWo) did not. These data demonstrate that this mAb is an adequate tool for targeting CEA-expressing tumors in experimental models.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000800006
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X1999000800006
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.32 n.8 1999
Fonte: | info:eu-repo/semantics/openAccess