Selective killing of laryngeal carcinoma cells by a monoclonal immunotoxin.

To overcome the lack of selectivity of present anticancer drugs, an alternative approach is described for laryngeal carcinoma cells. An immunotoxin is synthesized containing the toxic chain from ricin coupled to a monoclonal antibody against a laryngeal carcinoma cell line. The newly formed monoclonal immunotoxin selectively kills cells from laryngeal carcinoma cell lines, whereas various normal living cells are not affected. Control experiments rule out the possibility that toxicity can be attributed to contaminating traces of whole ricin toxin. The results indicate that minute amounts of the immunotoxin are selectively cytotoxic for living laryngeal carcinoma cells in vitro.