Inhibition of leukocyte migration in agar by soluble extract from a human ovarian carcinoma cell line.

A soluble membrane extract was prepared by a hypotonic extraction method from a cultured cell line, CKS, derived from serous cystadenocarcinoma of the ovary. The leukocyte migration inhibition assay in agar was used to determine the cell-mediated immune response with this extract in patients with ovarian carcinoma in comparison with patients with other benign or malignant tumors and normal healthy subjects. With 100 micrograms protein/ml of the extract, leukocytes from 15/25 patients with ovarian carcinoma showed positive response, whereas 5/30 patients with benign tumors, 2/23 patients with non-ovarian carcinomas, and 0/13 normal healthy controls did so. These findings suggested that the soluble membrane extract from the CKS cells specifically inhibited migration of leukocytes from patients with ovarian carcinoma. There was a tendency that the stage III or IV patients responded to the extract more frequently than the stage I patients irrespective of histological type of ovarian carcinoma. The migration inhibition assay with a basic encephalitogenic protein (100 micrograms protein/ml) from bovine brain was performed simultaneously with the ovarian cancer extract. One of 20 patients with ovarian carcinoma, 1/29 patients with benign tumors, 1/22 patients with non-ovarian carcinomas, and 0/13 normal healthy controls responded positively. Therefore, cross-reactivity between the basic protein and tumor-associated antigens could not be demonstrated in the present study.