A Chemical Biological Platform to Interrogate the Mechanisms of Anti-Cancer Activity of Splice-Switching Small Molecules

Alternative RNA splicing is an extraordinary process that generates proteomic diversity (estimated at up to 150,000 human proteins) from only 20,000 human genes. More than 90% of human genes use splicing to produce on average multiple protein isoforms, sometimes with antagonistic functions, to be expressed from a single gene. However, mutations affecting splicing can result in the onset of disease such as cancer. A prominent example is the aberrant splicing of the Bcl-X gene which is an apoptotic checkpoint. Bcl-x pre-mRNA encodes two isoforms with antagonistic functions. The major protein isoform (Bcl-xL) displays anti-apoptotic functions and is overexpressed in most cancer cells. Overexpression of the alternative protein isoform (Bcl-xS) results in caspase-mediated apoptotic cell death.
In collaboration with colleagues in Leicester (Ian Eperon and Cyril Dominguez), we have identified a small molecule (GQC-05) which induces a switch in Bcl-X splicing towards the pro-apoptotic Bcl-xS pre-mRNA isoform. Whilst GQC-05 displays potent anti-cancer in live cells, the exact molecular mechanisms of splice-switching action are currently unknown.
The overall objective of this PhD studentship is to establish a chemical biological platform to interrogate the molecular mechanisms of splice-switching. This will involve the development of new synthetic methodology to establish structure-activity-relationship profiling of GQC-05. The synthesis of chemical biological probes will also be developed that will assist in the identification of protein and RNA-binding partners of these splice-switching small molecules by mass spectrometry-based proteomics analysis in collaboration with Dr Nik Rattray.
This project will involve the development of novel chemical probes involved in protein and RNA identification, new mass spectrometry and activity-based protein profiling techniques to aid identification of binding partners, and in collaboration with our colleagues in Leicester, assisting in the identification of new chemotypes for suitable for further development as next-generation anti-cancer agents.