Date of Award

Spring 5-20-2019

Degree Type

Dissertation

Degree Name

PhD. Chemistry

Department

Chemistry and Biochemistry

Advisor

David Sabatino, Ph.D.

Committee Member

Jenny Zilberberg, Ph.D.

Committee Member

Cecilia Marzabadi, Ph.D.

Committee Member

Stephen Kelty, Ph.D.

Keywords

siRNA, Glucose Regulated Proteins (GRPs), Prostate Cancer, N-cadherin, siRNA nanostructures, siRNA bioconjugates

Abstract

Gene therapy is a potent and versatile nano-medicine strategy in the treatment of cancer. Of the many tools currently used in this application, short-interfering RNA (siRNA) are among the most commonly employed due to their ability to silence oncogenic mRNA with high precision through the RNA interference (RNAi) pathway potentially leading to cancer cell death. Our work revolves around silencing the Glucose-Regulated Proteins (GRPs) whose expressions are upregulated in cancerous tissues and are implicated in the proliferative, pro-survival, and anti-apoptotic pathways that govern tumor biology. Here we present a variety of applications to improve the potency and functionality of GRP-targeting siRNAs while investigating the role of these oncoproteins in cancer cell cytotoxicity and adhesion. We’ve generated branched RNA templates that have the ability to self-assemble into higher order siRNA nanostructures and are capable of delivering multiple siRNAs that can synergistically silence the GRPs in endometrial, breast, and cervical cancer. From the branched RNA templates, second generation bioconjugates were developed to include fluorescently labeled and fatty acid conjugated siRNAs in an effort to expand their functionality into theranostic and self-delivery applications. Using our silencing strategy, we’ve also revealed a novel role of the master GRP regulator, GRP78, in modulating the expression of N-cadherin, a mesenchymal marker pivotal in the progression of metastatic tumor cell adhesion to the bone microenvironment. Silencing of GRP78 ultimately led to a decrease in prostate cancer adhesion in a model bone co-culture system. Moreover, our latest work highlights a method for developing cancer-targeting and cell penetrating peptides for the targeted delivery of siRNA to prostate cancer cells. Together, these studies have introduced new technologies that can further enhance the potency and applicability of siRNAs in cancer gene therapy.

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