EFFECTS OF LAK CELLS IN THE PRESENCE OF I L-2 ON MCF-7 HUMAN BREAST-CANCER CELLS MAINTAINED IN ORGANOTYPIC CULTURE

Lymphokine Activated Killer (LAK) cells, stimulated by interleukine 2 (IL-2) have a pronounced antitumor effect in the therapy of melanoma a nd renal cancers. LAK cells were cultivated in presence of the nodules of the human breast adenocarcinoma cell line MCF-7 maintained in orga notypic culture to study the interactions between lymphocytes and brea st tumor cells. After two days of co-culture, the proliferation of MCF -7 nodules and that of LAK cells was diminished about five folds. The cytotoxic effect of the latter, appreciated by Chrome 51 release was u nchanged after the coculture. In histological sections, the penetratio n of the LAK cells into the MCF-7 nodules was accompanied by an increa se of tumor necrosis but also by a glandular differentiation of cancer ous tissue. Polarized epithelial cell formations bording neoplasic lum ens with intracytoplasmic vacuoles filled with mucus, appeared in the nodules. rhe immunohistochemistry underlines the presence of T lymphoc ytes marqued by UCHL1 and CD3 antibodies and of Natural Killer (NK) ce lls marqued by IOT10, located between the MCF-7 cancer cells. In elect ron microscopy, the membrane contacts were tight and were accompanied by the appearence of secondary lysosomes and nuclear alterations. The relatively low infiltration level of the nodules may lead to the suppo sition that an indirect mecanism will intervene in this dual action of a LAK cells: increase of necrosis, although partially, and developmen t of glandular and functional differentiation.