Abstract 2353: Analysis of noncoding mutations in cancer revealed novel potentially pathogenic recurrent mutations

Abstract

Abstract Introduction: 98% of mutations are non-coding mutations. Thus far, most non-coding mutations are ignored or merely classified as variant of unknown significance with a few exceptions, despite the fact that non-coding region plays significant role in regulations and other important biological processes. Although they would not be directly druggable, these non-coding mutations might be important for cancer etiology, response to treatments and prognosis assessments. Method: Mutations in non-coding genes, intron, upstream and downstream, and intergenic regions are collected from COSMIC and TCGA as defined in Ensemble GRCh37.75 gene definition and hg19 RefSeq. Over 15 million non-coding mutations are analyzed for recurrence over 10 samples. Mutations in neighborhood of IG genes and dbSNP150 polymorphisms are removed from further investigation. We analyzed remaining mutations for possible super enhancer and transcription factor binding. Result: 911 distinct recurrent mutations are identified. Promoter mutations in protein coding genes like MPRS31, NUDFB9, SZT2, WASF3 in addition to TERT are discovered. Intronic mutations of well-known cancer genes such as HIF1A, NF1, KMT2C, and ATR are discovered with their associated cancer type specificity. As for non-coding RNA's, lincRNA CROCCP2, LINC00969 and miRNA MIR4477 appear frequently. Only 182 mutations are reluctantly classified as intergenic; intergenic loci RP11-96F8.1-KSR1P1, MLLT10P1-DEFB115, and bP-21201H5.1-IGHV1OR21-1 contain unusually high recurrent mutations. Conclusion: Many non-coding mutations worth further investigation are found. Still, it is quite possible that many of these mutations might be artifacts resulting from paralogous alignments, gene definition compatibility and other technical issues. Importantly, we discovered novel intronic mutations in genes already associated with treatments. Mutations in intergenic regions might be involved in regulatory mechanisms and chromosomal structures. Understanding these non-coding mutations will further refine our understanding of biology as well as cancer. Citation Format: Takahiko Koyama, Laxmi Parida. Analysis of noncoding mutations in cancer revealed novel potentially pathogenic recurrent mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2353.