Epidermal Growth Factor Receptor Overexpression as a Target for Auger Electron Radiotherapy of Breast Cancer
Abstract
Overexpression of the epidermal growth factor receptor (EGFR) occurs in a high proportion of estrogen receptor-negative and hormone-resistant breast cancers. Our objective is to construct a human epidermal growth factor (hEOF)-immunoglobulin (CH1) fusion protein to deliver the Auger electron emitting radionuclide, 111 into the cytoplasm and nucleus of breast cancer cells for targeted radiotherapy. The gene for hEGF was amplified from plasmid pADH59 by the polymerase chain reaction (PCR) and inserted into pASK84 which contains the genes for CR1 and CK of IgG1%. The hEGF-CH1 gene was amplified from pASK84 by PCR and inserted into expression plasm id pGEX2T for expression in E. coli. Conditions for expression were optimized. The fusion protein was isolated using native or denaturing conditions. SDS- PAGE and Western blot analysis showed a pure protein with the expected molecular size (Mr 18 kDa). Flow cytometry against MDA-MB-468 cells and ELISA against purified EGFR demonstrated that the hEGF-CH1 protein exhibits preserved receptor-binding properties. Biodistribution studies in athymic mice with MDA- MB-468 breast cancer xenografts are in progress. In conclusion, we successfully generated a recombinant hEGF-CHl fusion protein of high purity which exhibits preserved receptor-binding properties.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1999
- Accession Number
- ADB250216
Entities
People
- Raymond M. Reilly
Organizations
- Toronto General Hospital