Synthesis and evaluation of small molecule inhibitors of pre-mRNA splicing to effectively modify gene expression

Abstract

The spliceosome is a highly complex molecular machine that still holds a lot of secrets for contemporary biology. It plays a crucial role as one of the various mechanisms involved in generating a plethora of different proteins, from a limited amount of genetic information, sealed in the form of DNA in the nucleus of living cells. Previous studies have tried to dissect this complex mechanism by inhibiting the spliceosome, in order to study its biological properties. Interestingly a significant number of inhibitors found, which target the specific U2 snRNP unit of the spliceosome, have been reported to have anti-cancer activity. Some of the most promising compounds, which resulted from this drug development approach, have almost made it to the drug market at the time of writing, for their antitumor activity. A vast amount of research has emerged concerning the biological processes that ultimately led to this activity. Previous work within the Whitehead group, which focused on developing inhibitors of the U5 snRNP unit of the spliceosome, has led to the discovery of a compound derived from the steroidal antibiotic fusidic acid that displayed significant splicing inhibitory activity. Lithocholic acid later emerged as another potential starting point for developing small molecule inhibitors of the U5 snRNP, as it was found to have similar levels of inhibition as the hit compound derived from fusidic acid. Lithocholic acid was a good starting point for further SAR studies, as it isn't heavily functionalised, making it a robust compound that can easily be diversified. A variety of compounds were generated from it, with new structural features and additional functional groups that unravelled new information about the target protein. Splicing assays also revealed that several of these compounds have superseded the level of inhibition achieved by the previously outlined hit compound.

Date of Award	31 Dec 2019
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Raymond O'Keefe (Supervisor) & Roger Whitehead (Supervisor)