Interleukin 4 receptor-directed cytotoxin therapy for human head and neck squamous cell carcinoma in animal models.

Receptors for interleukin 4 (IL-4R) are overexpressed on the surface of various human solid tumors including renal cell carcinoma, glioblastoma, Kaposi's sarcoma, and head and neck squamous cell carcinoma (SCCHN). On the basis of this preferential receptor overexpression, a novel IL-4R-targeted cytotoxin, IL-4 (38-37)-PE38KDEL, was developed in which circularly permuted IL-4 [IL-4 (38-37)] was fused to mutated form of Pseudomonas exotoxin (PE38KDEL). Despite the recognized expression of the IL-4R on SSCHN, the utility of a receptor-specific fusion protein for the treatment of this disease remains unknown.