Modulation of Cellular Behavior by Inhibition of Intracellular Enzymes to Enhance in Vitro Transient Non-Viral Polymer-Mediated Transgene Expression


Transgene delivery is a ubiquitously applied approach in which nucleic acids (DNA or RNA) are delivered from an external source to a target cell. This approach can be used a biological study tool or as a therapy to correct a mutated, over-expressed, under-expressed, or non-expressing gene. Many cationic vehicles (eg. polymers, liposomes, metal-phosphates, and magnetic nanoparticles) have been applied for delivering negatively charged nucleic acids to the nucleus of target cells, where the cell's machinery can transcribe the delivered gene, ultimately leading to protein expression. However, most applications of gene delivery, including those in clinical trials for therapeutic applications, utilize viral vehicles due to their relatively high efficacy in delivering transgene to the target nucleus. While viral vehicles have evolved to become incredibly efficient gene delivery vehicles, they pose issues including induction of host immune response, toxicity, and they can be expensive to synthesize. Additionally, their cargo load is generally limited when compared to chemically synthesized non-viral delivery vehicles. Given these drawbacks with viral carriers, it is imperative that a focus on the improvement of non-viral gene delivery efficacy ensues. Fortunately, much work on this research topic is underway.

One approach to improving non-viral gene delivery is to introduce functional groups to the delivery vehicles that assist the transgene/delivery complex in overcoming intracellular barriers. These include introducing "proton sponge" groups that help the transgene escape the endosomes, and conjugation of nuclear localization sequences, assisting the transgene in entering the host cell nucleus. A second approach to improve non-viral gene delivery is to modulate target cellular behavior by inhibiting enzymes within the cell, and this approach has been employed thoroughly in our laboratory. We have identified a multitude of enzymatic targets in cancer cells, whose inhibition leads to significant enhancement in expression of an exogenously delivered transgene. These targets include enzymes involved in cell cycle, transcription, as well as epigenetic modifiers. This project focuses mainly on enhancing transgene expression using the second method, modulating intracellular behavior in a way that makes cells more vulnerable to transgene expression. One key advantage to this method is the potential for synergistic therapeutic treatments. Enzyme inhibition can have therapeutic effects (eg. inhibition of cell cycle proteins is used in cancer treatments). If inhibition of this enzyme simultaneously enhances transgene delivery, then a gene with a therapeutic effect can be delivered with improved efficacy when treated with this inhibitor already possessing therapeutic value. This method of non-viral gene delivery is promising direction for future gene therapy applications.

Meeting Name

2014 AIChE Annual Meeting -- Food, Pharmaceutical and Bioengineering Division 2014 - Core Programming Area (2014: Nov. 16-21, Atlanta, GA)


Chemical and Biochemical Engineering

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Article - Conference proceedings

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© 2014 American Institute of Chemical Engineers (AIChE), All rights reserved.

Publication Date

01 Nov 2014

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