The overall objective of this application is to improve electric field-forced gene transfer in solid tumors. Gene therapy has a great potential to improve treatment of different diseases, including solid tumors, but it has been impeded by the difficulties of gene delivery to specific cells. Recent reports by other investigators and ourselves have demonstrated that plasmid DNA delivery can be enhanced through the use of pulsed electric fields. However, present methods for optimizing electric field-forced gene transfer, in terms of electric pulse characteristics (e.g., field strength and pulse duration), are still empirical and incomplete. The fundamental hypothesis in this proposal is that electric field-forced DNA transport in the vicinity of cells determines the amount of gene transfer through the transient pores in the plasma membrane of cells created during in vivo electroporation. To test this hypothesis, we will systematically quantify the mechanisms of interstitial transport of DNA in response to different electric pulses both ex vivo (Aim 1) and in vivo (Aim 2). The quantification will be based on unique experimental methods developed in our labs, and it may result in an identification of effective pulse sequences for improving interstitial transport of DNA. The improved transport in the identified electric fields will be further increased through modifications in tumor tissue structures, using matrix enzymes, hypertonic solutions, or apoptotic agents (Aim 3). These chemical treatments transiently increase the interstitial space and thus decrease the resistance to DNA transport. Quantitative results from the transport studies in Specific Aims 1 through 3 will finally be used to improve transfection efficiency and therapeutic efficacy of interleukin- 12 gene in solid tumors transplanted in mice (Aim 4). The goal of the proposed study is to establish effective experimental protocols for improving interstitial transport of plasmid DNA which in turn may result in an increase in transfection efficiency in solid tumors without increasing toxicity.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA094019-01A1
Application #
6475237
Study Section
Surgery and Bioengineering Study Section (SB)
Program Officer
Wolpert, Mary K
Project Start
2002-09-11
Project End
2007-08-31
Budget Start
2002-09-11
Budget End
2003-08-31
Support Year
1
Fiscal Year
2002
Total Cost
$325,829
Indirect Cost
Name
Duke University
Department
Biomedical Engineering
Type
Schools of Engineering
DUNS #
071723621
City
Durham
State
NC
Country
United States
Zip Code
27705
Wu, Mina; Yuan, Fan (2011) Membrane binding of plasmid DNA and endocytic pathways are involved in electrotransfection of mammalian cells. PLoS One 6:e20923
Henshaw, J; Mossop, B; Yuan, F (2011) Enhancement of electric field-mediated gene delivery through pretreatment of tumors with a hyperosmotic mannitol solution. Cancer Gene Ther 18:26-33
Henshaw, Joshua; Mossop, Brian; Yuan, Fan (2008) Relaxin treatment of solid tumors: effects on electric field-mediated gene delivery. Mol Cancer Ther 7:2566-73
Henshaw, Joshua W; Yuan, Fan (2008) Field distribution and DNA transport in solid tumors during electric field-mediated gene delivery. J Pharm Sci 97:691-711
Zaharoff, David A; Henshaw, Joshua W; Mossop, Brian et al. (2008) Mechanistic analysis of electroporation-induced cellular uptake of macromolecules. Exp Biol Med (Maywood) 233:94-105
Henshaw, Joshua W; Zaharoff, David A; Mossop, Brian J et al. (2007) Electric field-mediated transport of plasmid DNA in tumor interstitium in vivo. Bioelectrochemistry 71:233-42
Mossop, Brian J; Barr, Roger C; Henshaw, Joshua W et al. (2007) Electric fields around and within single cells during electroporation-a model study. Ann Biomed Eng 35:1264-75
Henshaw, Joshua W; Zaharoff, David A; Mossop, Brian J et al. (2006) A single molecule detection method for understanding mechanisms of electric field-mediated interstitial transport of genes. Bioelectrochemistry 69:248-53
Mossop, Brian J; Barr, Roger C; Henshaw, Joshua W et al. (2006) Electric fields in tumors exposed to external voltage sources: implication for electric field-mediated drug and gene delivery. Ann Biomed Eng 34:1564-72
Wang, Yong; Chen, Qing; Yuan, Fan (2005) Alginate encapsulation is a highly reproducible method for tumor cell implantation in dorsal skinfold chambers. Biotechniques 39:834, 836, 838-9

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