Cultured breast cystosarcoma phylloides cells and applications to patient therapy.

Malignant cystosarcoma phylloides (CP) is a relatively rare cancer of the breast. A CP tumor was processed as part of a tumor acquisition, propagation, and preservation program in patient biotherapy. Two tissue culture cell lines were developed from this tumor, one directly from the biopsy, another from a xenograft tumor grown in athymic mice. The two cell lines were similar in character. There was strong immunochemical reactivity with antibodies to vimentin, type I collagen, and type III collagen. There was no reactivity with antibodies to cytokeratin and epithelial membrane antigen. Both cell lines were aneuploid, clonogenic in soft agar, and tumorigenic in nude mice. 5 alpha-dihydrotestosterone and thyroxine added to the culture medium stimulated growth, while testosterone, 17 beta-estradiol, and 4-hydroxytamoxifen were without effect. Dexamethasone and cortisol were inhibitory at high doses (10(-6) M). Dibutyryl cyclic AMP, theophylline, and vitamin C were all inhibitory. The biopsy contained tumor-infiltrating lymphocytes which proliferated in cultures containing interleukin 2. The expanded lymphocytes were activated T cells which had the capacity to lyse tumor cells. These results suggest possibilities in the therapy of cystosarcoma phylloides involving vitamin C, certain hormones, and tumor-infiltrating lymphocytes.