# A Yeast-Based High-Throughput Screening Platform for the Discovery of Novel pre-mRNA Splicing Modulators

## TL;DR

This paper introduces a new yeast-based screening method to find molecules that affect RNA splicing, which could lead to new treatments for diseases linked to splicing errors.

## Contribution

A novel two-tiered yeast-based high-throughput screening platform for discovering splicing modulators is developed and validated.

## Key findings

- Four small molecules were identified that cause accumulation of unspliced pre-mRNA in yeast.
- One compound preferentially affects cancer cells with a specific splicing factor mutation (SRSF2P95H).
- Transcriptome analysis revealed widespread gene expression changes in SRSF2P95H-expressing cells treated with the compound.

## Abstract

Pre-mRNA splicing is a core process in eukaryotic gene
expression,
and splicing dysregulation has been linked to various diseases. However,
very few small molecules have been discovered that can modulate spliced
mRNA formation or inhibit the splicing machinery itself. This study
presents a novel high-throughput screening (HTS) platform for identifying
compounds that modulate splicing. Our platform comprises a two-tiered
screening approach: A primary screen measuring growth inhibition in
sensitized Saccharomyces cerevisiae (yeast) strains and a secondary screen that relies on production
of a fluorescent protein as a readout for splicing inhibition. Using
this approach, we identified 4 small molecules that cause accumulation
of unspliced pre-mRNA in vivo in yeast. In addition,
cancer cells expressing a myelodysplastic syndrome-associated splicing
factor mutation (SRSF2P95H) are more sensitive to one of
these compounds than those expressing the wild-type version of the
protein. Transcriptome analyses showed that this compound causes widespread
changes in gene expression in sensitive SRSF2P95H-expressing
cells. Our results demonstrate the utility of using a yeast-based
HTS to identify compounds capable of changing pre-mRNA splicing outcomes.