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Cancer development is a complex process involving both genetic and epigenetic changes. The SWI/SNF (switch/sucrose non‐fermentable) chromatin remodelling complex, one of the most studied ATP‐dependent complexes, plays an important role in coordinating chromatin structural stability, gene expression and post‐translational modifications. The SWI/SNF complex can be classified into BAF, PBAF and GBAF according to their constituent subunits. Cancer genome sequencing studies have shown a high incidence of mutations in genes encoding subunits of the SWI/SNF chromatin remodelling complex, with abnormalities in one or more of these genes present in nearly 25% of all cancers, which indicating that stabilizing normal expression of genes encoding subunits in the SWI/SNF complex may prevent tumorigenesis. In this paper, we will review the relationship between the SWI/SNF complex and some clinical tumours and its mechanism of action. The aim is to provide a theoretical basis to guide the diagnosis and treatment of tumours caused by mutations or inactivation of one or more genes encoding subunits of the SWI/SNF complex in the clinical setting. [ABSTRACT FROM AUTHOR]

Although large exons cannot be readily recognized by the spliceosome, many are evolutionarily conserved and constitutively spliced for inclusion in the processed transcript. Furthermore, whether large exons may be enriched in a certain subset of proteins, or mediate specific functions, has remained unclear. Here, we identify a set of nearly 3,000 SRSF3‐dependent large constitutive exons (S3‐LCEs) in human and mouse cells. These exons are enriched for cytidine‐rich sequence motifs, which bind and recruit the splicing factors hnRNP K and SRSF3. We find that hnRNP K suppresses S3‐LCE splicing, an effect that is mitigated by SRSF3 to thus achieve constitutive splicing of S3‐LCEs. S3‐LCEs are enriched in genes for components of transcription machineries, including mediator and BAF complexes, and frequently contain intrinsically disordered regions (IDRs). In a subset of analyzed S3‐LCE‐containing transcription factors, SRSF3 depletion leads to deletion of the IDRs due to S3‐LCE exon skipping, thereby disrupting phase‐separated assemblies of these factors. Cytidine enrichment in large exons introduces proline/serine codon bias in intrinsically disordered regions and appears to have been evolutionarily acquired in vertebrates. We propose that layered splicing regulation by hnRNP K and SRSF3 ensures proper phase‐separation of these S3‐LCE‐containing transcription factors in vertebrates. Synopsis: Although their recognition poses a challenge to spliceosomes, large exons are often conserved and spliced. Here, this is linked to their nucleotide composition, which drives splicing factor recruitment and endows encoded proteins with specific properties. Analysis of ˜ 3,000 SRSF3‐dependent large exons reveals enrichment for cytidine nucleotidesCytidine enrichment favors recruitment of splicing factors SRSF3 and hnRNP KInclusion of cytidine‐rich large exons encoding serine/proline‐rich intrinsically disordered regions (IDRs) is found in vertebrate transcription factorsLoss of IDR inclusion upon SRSF3 depletion‐induced exon‐skipping disrupts transcription factor phase separation. [ABSTRACT FROM AUTHOR]