BIOCHEMICAL, HISTOCHEMICAL AND CELL BIOLOGICAL INVESTIGATIONS ON THE ACTIONS OF MISTLETOE LECTIN-I, LECTIN-II AND LECTIN-III WITH HUMAN BREAST-CANCER CELL-LINES

Cytotoxicity of the mistletoe lectins I, II and III towards six human breast cancer cell lines was assessed using the Mossman assay. In addi tion, binding of the three mistletoe lectins to the separated membrane glycoproteins of these cell lines, the binding and uptake of these le ctins into the cells in tissue culture and the binding of the lectins to histological preparations of these cell lines were analysed. The re sults indicate that there are quantitative differences concerning the toxicity of these three lectins towards the different cell, lines. Fur thermore, the lectin binding pattern in the cell lines differed. In We stern blots, several membrane glycoproteins were labelled by the lecti ns. Our results indicate subtle differences between the three lectins with regard to the parameters mentioned above; however, the toxicity o f all three lectins from mistletoe is so similar that they all seem su itable for the construction of immunotoxins.