The use of cytotoxic plant lectins in cancer therapy.

As part of their defense mechanism against herbivores or phytophagous insects, many plant tissues contain lectins. Some of these lectins are potent toxins which kill animal cells by arresting protein synthesis. An attractive strategy for developing specifically cytotoxic chemotherapeutic agents is to link cell type-specific monoclonal antibodies to potent toxins. The plant protein ricin has emerged as the toxin of choice for such constructs.