NK activities and HNK-1+ cells in familial polyposis coli

Although natural killer cells are thought to play a major role in surveillance against tumor development, no systemic studies on natural killer cells and their activities have been reported in familial polyposis coli in which cancer always develops at an early age. Natural killer activities and natural killer cells were studied in 14 patients with familial polyposis coli. Peripheral blood lymphocytes from familial polyposis coli showed normal cytotoxicities against K562 cells, P4788 cells derived from colon cancer and Chang cells. The number of natural killer cells in peripheral blood lymphocytes identified by an immunofluorescence antibody method and that in gut tissue by immunoperoxidase staining using anti-HNK-1 monoclonal antibody were comparable to those seen in normal controls. These results led to the following conclusion: it seems unlikely that a deficiency or impairment of natural killer activity is one of backgrounds for the development and subsequent malignant change of adenomas in familial polyposis coli.