Gao, Yang
(2014)
REGULATING PRE-MRNA SPLICING AND TRANSCRIPTION USING SMALL MOLECULES FOR CANCER THERAPY.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Eukaryotic gene expression is an integral network encompassing chromatin packaging, transcription, capping, polyadenylation, splicing, mRNA nuclear export, and translation. Pre-mRNA splicing removes non-coding RNA sequences, generates proteomic diversity, and even affects other gene expression processes. Hence, dysregulated splicing has emerged as the origin of various diseases including cancer, representing an attractive therapeutic target. FR901464 is a natural bacterial metabolite that arrests tumor growth by interfering with the spliceosomal SF3b subcomplex. Meayamycin B, an FR901464 analogue synthesized by the Koide group, exhibited picomolar anti-proliferative activity in a broad spectrum of tumor cell lines.
The first goal of this thesis project was to further characterize the biological activity of meayamycin B and identify downstream effectors, thereby discovering novel combination therapeutics for cancer. To that end, we first optimized a cell-based reporter system for splicing inhibition, which was subsequently used for a comprehensive comparison of meayamycin B with recently reported splicing modulators, including spliceostatin A, herboxidiene, and meayamycin. This study provides a handy guide in terms of the splicing inhibitory activity of these widely utilized compounds in both basic and translational research.
To identify downstream effectors and their therapeutic applications, we focused on examining the B-cell lymphoma 2 (Bcl-2) family members that control the mitochondria-mediated cell death pathway –– apoptosis. This effort led us to myeloid cell leukemia sequence-1 (Mcl-1), a Bcl-2 family member that is recurrently correlated with drug resistance and tumor refractory. Meayamycin B reversed the dominant splicing isoform from Mcl-1L to Mcl-1S, resulting in a proapoptotic cellular environment. Taking advantage of this effect, we combined meayamycin B with Bcl-xL inhibitor ABT-737 to trigger apoptosis in cancer cell lines that were otherwise resistant to either single agent. This potent combination was characterized in vitro in non-small-cell lung carcinoma (NSCLC) and head and neck squamous cell carcinoma (HNSCC) models.
The second part of this thesis project was devoted to the biological characterization of a fungal metabolite TMC-205 and its stable analogs. These indole derivatives are both activators of Simian virus 40 (SV40) promoter and inhibitors of firefly luciferase, representing a new generation of anticancer agents with a multifactorial mode of action.
Share
| Citation/Export: |
|
| Social Networking: |
|
Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
|
| Date: |
28 May 2014 |
| Date Type: |
Publication |
| Defense Date: |
11 March 2014 |
| Approval Date: |
28 May 2014 |
| Submission Date: |
12 March 2014 |
| Access Restriction: |
1 year -- Restrict access to University of Pittsburgh for a period of 1 year. |
| Number of Pages: |
140 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Chemistry |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
SF3B1, splicing, meayamycin B, cancer, combination therapy |
| Date Deposited: |
28 May 2014 20:51 |
| Last Modified: |
15 Nov 2016 14:17 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/20719 |
Metrics
Monthly Views for the past 3 years
Plum Analytics
Actions (login required)
 |
View Item |
![[feed]](/images/feed-icon-32x32.png){kind=icon}