A molecular portrait of microsatellite instability across multiple cancers

• Published in: Nature communications Vol. 8; no. 1; pp. 15180 - 12
• Main Authors: Cortes-Ciriano, Isidro, Lee, Sejoon, Park, Woong-Yang, Kim, Tae-Min, Park, Peter J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 06.06.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 45/23; 631/114/2413; 631/67/1857; 631/67/69; 692/53/2421; Deoxyribonucleic acid; DNA; DNA Repair - genetics; Genome, Mitochondrial - genetics; Genomes; Genotype & phenotype; Humanities and Social Sciences; Humans; Immunotherapy; Informatics; Melanoma; Microsatellite Instability; Mitochondrial DNA; multidisciplinary; Mutation; Neoplasms - classification; Neoplasms - genetics; Oncogenes; Ovarian cancer; Phenotype; Prediction models; Science; Science (multidisciplinary); Tumors; Whole Exome Sequencing; Whole Genome Sequencing; Yeast; United States > US; South Korea; Massachusetts
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms15180

Microsatellite instability (MSI) refers to the hypermutability of short repetitive sequences in the genome caused by impaired DNA mismatch repair. Although MSI has been studied for decades, large amounts of sequencing data now available allows us to examine the molecular fingerprints of MSI in greater detail. Here, we analyse ∼8,000 exomes and ∼1,000 whole genomes of cancer patients across 23 cancer types. Our analysis reveals that the frequency of MSI events is highly variable within and across tumour types. We also identify genes in DNA repair and oncogenic pathways recurrently subject to MSI and uncover non-coding loci that frequently display MSI. Finally, we propose a highly accurate exome-based predictive model for the MSI phenotype. These results advance our understanding of the genomic drivers and consequences of MSI, and our comprehensive catalogue of tumour-type-specific MSI loci will enable panel-based MSI testing to identify patients who are likely to benefit from immunotherapy. Some cancers with DNA mismatch repair deficiency display microsatellite instability. Here the authors analyse twenty three cancer types at the exome and whole-genome level, and identify loci with recurrent microsatellite instability that could be used to identify patients who would benefit from immunotherapy.