Vector design influences hepatic genotoxicity after adeno-associated virus gene therapy

J Clin Invest. 2015 Feb;125(2):870-80. doi: 10.1172/JCI79213. Epub 2015 Jan 20.


The use of adeno-associated virus (AAV) as a gene therapy vector has been approved recently for clinical use and has demonstrated efficacy in a growing number of clinical trials. However, the safety of AAV as a vector has been challenged by a single study that documented hepatocellular carcinoma (HCC) after AAV gene delivery in mice. Most studies have not noted genotoxicity following AAV-mediated gene delivery; therefore, the possibility that there is an association between AAV and HCC is controversial. Here, we performed a comprehensive study of HCC in a large number of mice following therapeutic AAV gene delivery. Using a sensitive high-throughput integration site-capture technique and global expressional analysis, we found that AAV integration into the RNA imprinted and accumulated in nucleus (Rian) locus, and the resulting overexpression of proximal microRNAs and retrotransposon-like 1 (Rtl1) were associated with HCC. In addition, we demonstrated that the AAV vector dose, enhancer/promoter selection, and the timing of gene delivery are all critical factors for determining HCC incidence after AAV gene delivery. Together, our results define aspects of AAV-mediated gene therapy that influence genotoxicity and suggest that these features should be considered for design of both safer AAV vectors and gene therapy studies.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Carcinoma, Hepatocellular* / genetics
  • Carcinoma, Hepatocellular* / metabolism
  • Carcinoma, Hepatocellular* / therapy
  • Dependovirus*
  • Genetic Therapy / methods*
  • Genetic Vectors*
  • Liver Neoplasms* / genetics
  • Liver Neoplasms* / metabolism
  • Liver Neoplasms* / therapy
  • Mice
  • Mice, Mutant Strains
  • Pregnancy Proteins / genetics
  • Pregnancy Proteins / metabolism
  • Transduction, Genetic*


  • Pregnancy Proteins
  • Rtl1 protein, mouse