Abstract 1513: Pan-cancer analysis of alternative splicing patterns and association to genomic aberrations

Alternative splicing of pre-messenger RNA is responsible for the diversity of transcriptome and proteome, with the majority of multi exon genes producing multiple transcripts. Aberrations in regulative factors of alternative splicing are known to produce transcript isoforms associated with cancer progression and prognosis. Both mutations in the proximity of spliced regions and mutations in and regulation of previously identified splicing factor genes are known to alter splicing patterns. In this study, we utilized publicly available TCGA data to study association patterns between alternative splicing and its regulatory elements across multiple cancer tissue types. We collected evidence of splicing patterns of annotated isoforms in addition to novel patterns identified using our previously developed tools using RNA-seq data. We mined for associations between somatic mutations and changes of splicing patterns as well as genome and transcriptome level changes in splicing factors. Selective transcriptome assembly was done in loci with differentially expressed patterns and novel patterns with sufficient evidence to identify transcript isoforms and quantify isoform specific expression. In our study we compiled a catalogue of splicing patterns and their changes across multiple cancer types. Integration of this comprehensive set of quantified splicing patterns with data on proximal mutations and aberrations in splicing factors resulted in statistically relevant associations with clinical phenotypes. Our analysis enables identification of mechanisms behind splicing aberrations common to all cancers and cancer specific splicing patterns. Citation Format: Sergei Häyrynen, Matti Nykter. Pan-cancer analysis of alternative splicing patterns and association to genomic aberrations. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1513.