Abstract
Responses to molecularly targeted therapies can be highly variable and depend on mutations, fluctuations in target protein levels in individual cells and drug delivery. The ability to rapidly quantitate drug response in cells harvested from patients in a point-of-care setting would have far reaching implications. Capitalizing on recent developments with miniaturized diagnostic NMR (DMR) technologies, we have developed a magnetic nanoparticle based approach to directly measure both target expression and drug binding in freshly harvested human cancer cells. The method involves covalent conjugation of a small molecule drug to a magnetic nanoparticle that is then used as a read-out for target expression and drug binding affinity. Using poly(ADP-ribose) polymerase (PARP) inhibition as a model system, we developed an approach to distinguish differential expression of PARP across various cell lines with excellent correlation of DMR measurements to gold standards such as flow cytometry (r2 = 0.97) and western blotting (r2 = 0.92). We also sought to mimic drug pharmacodynamics ex-vivo through competitive target-drug binding and could quantify the relative binding affinities of several PARP inhibitors (e.g. Olaparib, Velaparib, AG-014699, and 3-aminobenzamide) in whole cells. Finally, we demonstrate the potential to perform such measurements directly in clinical samples. Further applications of the assay could result in a drug development platform to probe drug binding in cells, the identification of resistant cancer cells, and the ability to determine whether a drug has reached its target.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1968. doi:1538-7445.AM2012-1968
- ©2012 American Association for Cancer Research
Volume 72, Issue 8 Supplement
