Cytotoxic activity of a recombinant fusion protein between insulin-like growth factor I and Pseudomonas exotoxin

T I Prior, L J Helman, D J FitzGerald, I Pastan
1991 Cancer Research  
A chimeric toxin in which the cell binding domain of Pseudomonas exotoxin was replaced with mature human insulin-like growth factor I (IGF-I) was produced in Escherichia coli. This protein, IGF-I-PE40, was cytotoxic to human cell lines derived from a variety of tumor types, with a breast carcinoma line (MCF-7) and two hepatoma lines (HEP3B and HEPG2) showing the highest sensitivity to the toxin. The specificity of IGF-I-PE40 cytotoxicity was confirmed through competition with excess IGF-I and
more » ... excess IGF-I and through blockage of toxin binding using an antibody specific to the type I IGF receptor. A potential interaction between the toxin and soluble IGF-binding proteins was also demonstrated. IGF-I-PE40 may be useful in the selective elimination of cells bearing the type I IGF receptor.
pmid:1846308 fatcat:5g567edbdvbelc2qz77tec6vry