Inhibition of leucocyte migration by potassium chloride extracts of human tumor cells in ascites and from tissues.

Human gastric cancer-associated antigens were solubilized from fresh ascites and surgical specimens by 3M KCl extraction. The antigenicity of these extracts was measured by leucocyte migration inhibition assay with an improved modification devised in this laboratory. Antigens extracted mutually reacted with autologous and allogeneic leucocytes taken from cancer patients. The out of 11 (27%) patients and 7 out of 28 (25%) patients with various cancers showed positive migration index values against 13 ascites tumor cell antigens in the autologous and allogeneic reaction systems, respectively. Reactions were positive in 4 out of 10 patients with gastric cancer against autologous antigens, and in 10 out of 26 (38%) of the patients against allogeneic tumor antigens. On the other hand, one patient with gastric cancer reacted well with various sources of antigens extracted from allogeneic cells of gastric cancer, while the other patient with gastric cancer did not react with any of five gastric cancer antigens tested so far. These findings suggested that the cell-mediated immune response of patients with gastric cancer against autologous and allogeneic tumor antigens extracted was detectable in the test system. It is considered at present that the eM KCl antigen may be relate to human leucocyte antigen, and some common antigenic reactants capable of reacting with several gastric cancer may be involved in this reaction.