Targeted Gene Therapy for Breast Cancer
Abstract
The amplification of the HER-2/neu oncogene is a frequent genetic alteration found in 25-30% of all breast cancer cases and has been correlated with shortened disease-free and overall survival. The alteration leads to increased copy number of the gene and subsequent overexpression of the protein on the surface of cancer cells. The extracellular domain (ECD) of the protein acts as a receptor for transmission of growth regulatory signals into the cell. High numbers of HER-2/neu proteins on these particular cancer cells could be used as targets for the refinement of a more specific cancer therapy. The delivery of therapeutic genes to cancer cells overexpressing breast cancer cells mediated by engineered forms of HER-2/neu monoclonal antibodies is the goal of this project. We have generated four novel monoclonal antibodies (mAbs) targeted to the HER-2/neu ECD. Two mAbs, 5A7 and 11F11, were produced by hybridomas derived from mice immunized by a recombinant HER-2/neu ECD tagged by a polyhistidine peptide. Two other mAbs, 8H11 and 10H8, were produced by hybridomas derived from mice immunized with live HER-2/neu overexpressing cell lines. All four mAbs have been extensively characterized by immunohistochemistry, immunoblotting, and antibody internalization assays. Only 8H11 and 10H8 can localize to the surface of live HER-2/neu cells and subsequently be internalized by endocytosis. In order to generate a novel delivery vehicle to target cancer cells specifically, we have isolated the genes encoding the variable regions of the two best candidate mAbs, 8H11 and 10H8. By reverse-transcriptase polymerase chain reaction, we have isolated and sequenced the coding regions of both the variable heavy and variable light chains of both mAbs.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1998
- Accession Number
- ADB240907
Entities
People
- Jinha M. Park
Organizations
- University of Southern California