Colon cancer cells in peripheral blood of cancerous tamarins.

Diagnosing colon cancer in its early stages would lower the mortality rate. The cotton-top tamarin, Saguinus oedipus, serves as a model for the study of human colon cancer. This New World monkey has a high incidence of colitis and colon cancer. The mouse anti-human monoclonal antibody BR55.2, with specificity for human colon adenocarcinoma, was biotinylated. Peripheral blood mononuclear cells (PBMC) from animals with colon cancer were fluorescently stained with the biotinylated BR55.2. These results showed the cross-reactivity of mouse anti-human colon cancer monoclonal antibody to the PBMC of cancerous tamarins. Antibodies from either cancerous or chronic colitis tamarins were also biotinylated. Fluorescently labeled cells were detected when PBMC from cancerous tamarins were incubated with biotinylated antibodies from cancerous tamarins. Cytofluorographic analysis also showed a significant 4.5-fold difference in the percentage of fluorescently labeled PBMC between cancerous and chronic colitis tamarins when stained with biotinylated antibodies from cancerous tamarins. DNA flow cytometry analysis showed that PBMC from cancerous tamarins have a higher percentage of aneuploid cells than PBMC from chronic colitis tamarins.