Integrated analysis of whole genome and transcriptome sequencing reveals diverse transcriptomic aberrations driven by somatic genomic changes in liver cancers

PLoS One. 2014 Dec 19;9(12):e114263. doi: 10.1371/journal.pone.0114263. eCollection 2014.

Abstract

Recent studies applying high-throughput sequencing technologies have identified several recurrently mutated genes and pathways in multiple cancer genomes. However, transcriptional consequences from these genomic alterations in cancer genome remain unclear. In this study, we performed integrated and comparative analyses of whole genomes and transcriptomes of 22 hepatitis B virus (HBV)-related hepatocellular carcinomas (HCCs) and their matched controls. Comparison of whole genome sequence (WGS) and RNA-Seq revealed much evidence that various types of genomic mutations triggered diverse transcriptional changes. Not only splice-site mutations, but also silent mutations in coding regions, deep intronic mutations and structural changes caused splicing aberrations. HBV integrations generated diverse patterns of virus-human fusion transcripts depending on affected gene, such as TERT, CDK15, FN1 and MLL4. Structural variations could drive over-expression of genes such as WNT ligands, with/without creating gene fusions. Furthermore, by taking account of genomic mutations causing transcriptional aberrations, we could improve the sensitivity of deleterious mutation detection in known cancer driver genes (TP53, AXIN1, ARID2, RPS6KA3), and identified recurrent disruptions in putative cancer driver genes such as HNF4A, CPS1, TSC1 and THRAP3 in HCCs. These findings indicate genomic alterations in cancer genome have diverse transcriptomic effects, and integrated analysis of WGS and RNA-Seq can facilitate the interpretation of a large number of genomic alterations detected in cancer genome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carcinoma, Hepatocellular / genetics*
  • Carcinoma, Hepatocellular / metabolism
  • Case-Control Studies
  • Clonal Evolution*
  • Gene Expression Regulation, Neoplastic
  • Genome, Human*
  • Humans
  • Liver Neoplasms / genetics*
  • Liver Neoplasms / metabolism
  • Mutation*
  • Oncogenes / genetics
  • Transcriptome*

Grants and funding

Funding for this work came from the RIKEN President's Fund 2011, the Princess Takamatsu Cancer Research Fund, Takeda Science Foundation, Grand-in Aid for Scientific Research on Innovative Areas (Integrative Systems Understanding of Cancer for Advanced Diagnosis, Therapy and Prevention), and Grant-in-Aid for Young Scientists (B) 24700272. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.