Organic Isothiocyanates: Dietary Modulators of Doxorubicin Resistance in Breast Cancer
Abstract
Drug resistance is the main cause for therapeutic failure and death in breast cancer. Our goal is to evaluate dietary organic isothiocyanates (ITCs) as inhibitors of MDR. Our studies have demonstrated that phenethyl ITC (PEITC), benzyl ITC (BITC) and naphthyl ITC (NITC) can inhibit P-glycoprotein-, Multidrug Resistance-associated protein (MRPl)- and Breast Cancer Resistance Protein (BCRP)-mediated efflux, in cell lines that overexpress these transport proteins. Studies evaluating the mechanism of this interaction have suggested that PEITC is an inhibitor, but not a substrate for P-gp. PEITC represents a substrate for BCRP, and alters MRPl-mediated transport through binding interactions, as well as depletion of the cofactor for transport, glutathione. HPLC assays have been developed to determine the concentrations of these ITOs in biological samples, and a novel LC/MS/MS assay developed for PEITC, in order to obtain the needed specificity and sensitivity for in vivo studies. The stability and pharmacokinetics of NITC and PEITC have been determined for the first time. These studies represent the first report of inhibition of the ABC efflux proteins, P-glycoprotein, MRPl and BCRP, which are important determinants of MDR. The ITCs may represent a new class of inhibitors of MDR in breast cancer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2004
- Accession Number
- ADA427922
Entities
People
- Marilyn E. Morris
Organizations
- University at Buffalo