Chapter 2 Browse
2.1 In-Depth Understanding of the Landscapes of Mutational Signatures in Human Cancers
The COSMIC database has categorized 30 reference signatures based on an analysis of 10,952 exomes and 1,048 genomes across 40 distinct types of human cancer. However, only limited information about the signature distribution across cancer types is provided by current release of COSMIC database.
In order to provide an in-depth
and efficient
way for inspecting the signature landscapes in human cancers, mSignatureDB integrates publicly available R packages and in-house scripts to determine the contributions of 30 known COSMIC signatures in 15,780 tumors across 73 cancer projects (33 TCGA and 40 ICGC cancer projects). The landscape of each COSMIC signature in each cancer project or individual samples is displayed as Dot Matrix with bubble sizes
rendered according to signature contributions
.
Detailed information such as the full name of cancer project
, signature association
, signature contribution
, primary site
,and country
can be displayed as pop-up windows alongside the figures.
In breif, mSignatureDB can provide the most comprehensive roadmap describing the signatures of mutational processes operative in individual TCGA/ICGC tumors, which may be beneficial to explore different combinations of mutational signatures that are representative and distinct in specific cancer types or populations.
2.1.1 By Project
2.1.2 By Primary Site
2.1.3 By Country
2.1.4 By Sample
2.2 Link to COSMIC Reference Signautres
The profile of each signature is displayed as contribution of 96 trinucleotide contexts.
96 possible mutation types = 6 substitution types (C>A, C>G, C>T, T>A, T>C, and T>G) * 4 types of 5’base * 4 types of 3’base