abstract: Cancer is the second leading cause of death in the United States and novel methods of treating advanced malignancies are of high importance. Of these deaths, prostate cancer and breast cancer are the second most fatal carcinomas in men and women respectively, while pancreatic cancer is the fourth most fatal in both men and women. Developing new drugs for the treatment of cancer is both a slow and expensive process. It is estimated that it takes an average of 15 years and an expense of $800 million to bring a single new drug to the market. However, it is also estimated that nearly 40% of that cost could be avoided by finding alternative uses for drugs that have already been approved by the Food and Drug Administration (FDA). The research presented in this document describes the testing, identification, and mechanistic evaluation of novel methods for treating many human carcinomas using drugs previously approved by the FDA. A tissue culture plate-based screening of FDA approved drugs will identify compounds that can be used in combination with the protein TRAIL to induce apoptosis selectively in cancer cells. Identified leads will next be optimized using high-throughput microfluidic devices to determine the most effective treatment conditions. Finally, a rigorous mechanistic analysis will be conducted to understand how the FDA-approved drug mitoxantrone, sensitizes cancer cells to TRAIL-mediated apoptosis. / Dissertation/Thesis / Ph.D. Chemical Engineering 2013

Retinitis Pigmentosa (RP) is an incurable inherited retinal degeneration affecting approximately 1 in 4,000 individuals globally. The aim of this dissertation was to identify drugs that can help patients suffering from the disease. To accomplish this goal, the zebrafish was utilized as a model for RP to perform <i>in vivo</i> drug screening. The zebrafish RP model expresses a human rhodopsin transgene which contains a premature stop codon at position 344 (<i>Tg</i>(<i>rho:Hsa.RH1_Q344X</i>)). This zebrafish model exhibits significant rod photoreceptor degeneration beginning at 7 days post fertilization (dpf). To assess the visual consequence of this rod degeneration the zebrafish behavior visual motor response (VMR) was assayed under scotopic conditions. The Q344X RP model larvae displayed a deficit in this VMR in response to a scotopic light offset. This deficit in behavior was utilized to perform a drug screen to identify compounds that could ameliorate the deficient Q344X VMR. The ENZO SCREEN-WELL® REDOX library was chosen to be screened since oxidative stress may increase RP progression in a non-specific manner. From this library, a β-blocker, carvedilol, was identified as a compound that improved the Q344X VMR behavior. This drug was also able to increase rod number in the Q344X retina. Carvedilol was shown to be capable of working directly on rods by demonstrating that the drug can signal through the adrenergic pathway in the rod-like human Y79 cell line. Since carvedilol is an FDA-approved drug, this screening paradigm was utilized to screen the Selleckchem FDA-approved library to identify more drugs that can potentially be repurposed to treat RP like carvedilol. Additionally, this scotopic VMR assay was used to demonstrate that it can identify behavioral deficits in the P23H RP model zebrafish<i> (Tg</i>(<i>rho:Hsa.RH1_P23H</i>)). This dissertation work provides a potential FDA-approved drug for RP treatment and sets the foundation for future drug screening to identify more drugs to treat different forms of RP.