A Monoclonal Antibody Recognizing Human Cancers with Amplification/Overexpression of the Human Epidermal Growth Factor Receptor

• Published in: Proceedings of the National Academy of Sciences - PNAS 2003-01, Vol.100 (2), p.639-644
• Main Authors: Jungbluth, Achim A., Stockert, Elisabeth, H. J. Su Huang, Collins, Vincent P., Coplan, Keren, Iversen, Kristin, Kolb, Denise, Johns, Terrance J., Scott, Andrew M., Gullick, William J., Ritter, Gerd, Cohen, Leonard, Scanlan, Matthew J., Cavanee, Webster K., Old, Lloyd J.
• Format: Article
• Language: English
• Subjects: Animals; Antibodies; Antibodies, Monoclonal - therapeutic use; Biological Sciences; Cancer; Cell lines; Glioblastoma; Glioblastoma - chemistry; Glioblastoma - therapy; Heterologous transplantation; Humans; Laboratory staining techniques; Medical research; Mice; Mice, Inbred BALB C; Neoplasm Transplantation; Neoplasms - chemistry; Neoplasms - therapy; Non small cell lung carcinoma; Physical growth; Reactivity; Receptor, Epidermal Growth Factor - analysis; Receptor, Epidermal Growth Factor - genetics; Receptor, Epidermal Growth Factor - immunology; Squamous cell carcinoma; Transplantation, Heterologous; Tumor Cells, Cultured; Tumors
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.232686499

Epidermal growth factor receptor (EGFR) has attracted considerable attention as a target for cancer therapy. Wild-type (wt)EGFR is amplified/overexpressed in a number of tumor types, and several mutant forms of the coding gene have been found, with Δ EGFR, a deletion mutation lacking exons 2-7 of the external domain, being the most common and particularly associated with glioblastoma. We generated monoclonal antibodies (mAbs) against NR6Δ EGFR(mouse fibroblast line NR6 transfected with Δ EGFR). mAb 806 with selective reactivity for NR6Δ EGFRin mixed hemadsorption assays, fluorescence-activated cell sorting, Western blot, and immunohistochemistry was analyzed in detail and compared with mAbs 528 (anti-wtEGFR) and DH8.3 (anti-Δ EGFR). In xenograft tumors and molecularly pretyped glioblastomas, the reactivity pattern was as follows: 528 reactive with amplified and nonamplified wtEGFR; DH8.3 reactive with Δ EGFR; and 806 reactive with amplified/overexpressed wtEGFR (with or without Δ EGFR). In normal tissues, 528 but not DH8.3 or 806 was widely reactive with many organs, e.g., liver expressing high EGFR levels. In glioblastoma and non-CNS tumor panels, 806 was reactive with a high proportion of glioblastomas and a substantial number of epithelial cancers of lung and of head and neck. DH8.3 reactivity was restricted to Δ EGFR-positive glioblastoma. Thus, 806 represents a category of mAbs that recognizes tumors with EGFR amplification/overexpression but not normal tissues or tumors with normal EGFR levels. Our study also indicates that Δ EGFR is restricted to glioblastoma, in contrast to other reports that this mutation is found in tumors outside the brain.