Binding of Recombinant Mistletoe Lectin (Aviscumine) to Resected Human Adenocarcinoma of the Lung

Background: Lectins, carbohydrate proteins, bind to glycoconjugates of all mammalian cells, including cancer cells. Aberrant glycosylation, detected by lectin histochemistry, can predict outcome in some tumour entities. One such lectin is aviscumine (recombinant mistletoe lectin). Aviscumine has cytotoxic effects and can therefore be used as anti-tumour therapy. Materials and Methods: Lectin histochemistry with aviscumine was performed on primary tumour sections from resected adenocarcinoma of the lung. Staining results were then correlated with the clinical course of the patients. Results: Most of the adenocarcinomas (92.5%) bound aviscumine. Kaplan-Meier analysis revealed no correlation between aviscumine binding and progression-free survival or overall survival. Conclusion: These results suggest that for the selected group of patients with adenocarcinoma of the lung aviscumine binding activity can not serve as a prognostic factor. More strikingly, however, aviscumine binds to malignant cells in 92.5% of the patients. This is an indicator for the use of aviscumine as a possible target for tumour therapy. Lectins are carbohydrate-binding proteins of non- immunological origin, which often multivalently bind to carbohydrate residues of glycoconjugates. This study focuses on the mistletoe lectins (MLs) derived from the European mistletoe (Viscum album). Three different MLs (ML-I, ML-