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Date of Graduation
MicroRNAs (miRNAs) are a group of post-transcriptional, negative regulators of gene expression, consisting of ~19-24 nucleotides. Since their discovery in 1993, miRNAs have been found to be involved in a diverse amount of cellular and disease pathways, including certain types of cancer. Overexpression of certain oncogenic miRNAs, including miRNA-31, have been shown to play a role in cancer cell development. Recent findings have suggested that miRNAs play a significant role in every stage of colorectal cancer (CRC) initiation, progression, and development, as well as induce resistance to chemotherapy drugs like 5-FU. In particular, research has shown that increased levels of miRNA-31 cause 5-FU resistance in CRC and that suppression of miRNA-31 expression will increase the sensitivity of CRC cells to 5-FU increasing the likelihood of survival of patients, especially in the case of relapse in the cancer. Numerous FDA drugs that have been designed to target protein to promote a biological effect are typically evaluated for off-target effects and selectivity against similar proteins. However, it has become increasingly evident that these protein-targeting drugs also affect miRNA expression. The goal of this research was to identify a small molecule inhibitor of miRNA-31 expression by repurposing an FDA approved drug. The compounds were identified using the Psmir database which predicts associations between small molecule compounds and miRNA expression. FDA-approved drugs were selected based on their ability to inhibit miRNA-31 and methods for their evaluation were proposed. The small molecule compounds identified in the Psmir database were requested from the Developmental Therapeutics Program though the National Institutes of Health National Cancer Institute (NIH NCI) and 14 small molecule compounds were obtained. A luciferase assay for the primary evaluation of miRNA-31 expression still requires optimization, but the expression and purification of the miRNA-31 pmirGLO and empty vector were completed. An optimized qRT-PCR assay for secondary evaluation of miRNA-31 expression was completed, finding miRNA-16 and miRNA-93 as suitable housekeeping genes for qRT-PCR normalization.
Sienkiewicz, Nicholas, "Biological Evaluation of FDA-Approved Drugs as miRNA-31 Inhibitors using Real Time QRT-PCR and a Luciferase Assay" (2020). Honors Theses. 3305.
Honors Thesis-Open Access