New Enzyme Prodrug and Methionine-Depletion Combination Therapy of Breast Cancer Designed for Effective Delivery to the Tumor
Abstract
The L-methioninase-annexin V fusion protein (FP) was produced from recombinant E. coli in good purity and relatively good yield. As indicated by measuring the dissociation constant (Kd), purified FP binds strongly to human endothelial cells, MCF-7 breast cancer cells, and MDA-MB-231 breast cancer cells grown in vitro. Hydrogen peroxide was found not to be needed to induce exposure of PS on the endothelial cells. The following Kd values were determined: 1.7 nM for endothelial cells, 1.9 nM for MCF-7 cells, and 2.2 nM for MDA-MB-231 cells. The amount of FP bound on the three cell lines in vitro was found to decline steadily over 3 days, but there was still some FP bound at day 3. The rate of change of FP bound, normalized by the number of viable cells present, was the lowest for the endothelial cells. In tests of this enzyme/prodrug system in vitro, significant killing of endothelial and MDA-MB-231 cells was found at a SeMet concentration of 10 micron M; for MCF-7 cells there was significant killing of cells at 100 micron M SeMet. These results provide strong support for the idea that this enzyme/prodrug system will lead to damage of the tumor vasculature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2009
- Accession Number
- ADA541307
Entities
People
- Roger G. Harrison
Organizations
- University of Oklahoma