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Published on: November 1, 2024
A histone deacetylase inhibitor enhances recombinant adeno-associated virus-mediated gene expression in tumor cells
Takashi Okada1, Ryosuke Uchibori, Mayumi Iwata-Okada
1Division of Genetic Therapeutics, Center for Molecular Medicine, Jichi Medical School, 3311-1 Yakushiji, Minami-Kawachi, Tochigi 329-0498, Japan. tokada@jichi.ac.jp
Abstract:
The transduction of cancer cells using recombinant adeno-associated virus (rAAV) occurs with low efficiency, which limits its utility in cancer gene therapy. We have previously sought to enhance rAAV-mediated transduction of cancer cells by applying DNA-damaging stresses. In this study, we examined the effects of the histone deacetylase inhibitor FR901228 on tumor transduction mediated by rAAV types 2 and 5. FR901228 treatment significantly improved the expression of the transgene in four cancer cell lines. The cell surface levels of alpha v integrin, FGF-R1, and PDGF-R were modestly enhanced by the presence of FR901228. These results suggest that the superior transduction induced by the HDAC inhibitor was due to an enhancement of transgene expression rather than increased viral entry. Furthermore, we characterized the association of the acetylated histone H3 in the episomal AAV vector genome by using the chromatin immunoprecipitation assay. The results suggest that the superior transduction may be related to the proposed histone-associated chromatin form of the rAAV concatemer in transduced cells. In the analysis with subcutaneous tumor models, strong enhancement of the transgene expression as well as therapeutic effect was confirmed in vivo. The use of this HDAC inhibitor may enhance the utility of rAAV-mediated transduction strategies for cancer gene therapy.
Insights
This study shows that a histone deacetylase inhibitor, FR901228, significantly enhances recombinant adeno-associated virus (rAAV) gene delivery to cancer cells. This improved transduction boosts transgene expression and therapeutic effects in vivo, advancing cancer gene therapy.
Area of Science:
- Oncology
- Gene Therapy
- Molecular Biology
Background:
- Recombinant adeno-associated virus (rAAV) transduction of cancer cells is inefficient, limiting its use in gene therapy.
- Previous research explored DNA-damaging stresses to improve rAAV transduction efficiency.
Purpose of the Study:
- To investigate the effect of the histone deacetylase inhibitor FR901228 on rAAV-mediated tumor transduction.
- To determine if FR901228 enhances viral entry or transgene expression.
Main Methods:
- Treatment of four cancer cell lines with FR901228 and rAAV types 2 and 5.
- Analysis of transgene expression and cell surface receptor levels (alpha v integrin, FGF-R1, PDGF-R).
- Chromatin immunoprecipitation assay to assess histone H3 acetylation on the episomal AAV vector genome.
- In vivo studies using subcutaneous tumor models.
Main Results:
- FR901228 significantly improved transgene expression in cancer cell lines.
- Modest enhancement of cell surface receptors (alpha v integrin, FGF-R1, PDGF-R) was observed.
- Evidence suggests enhanced transgene expression, not increased viral entry, is responsible for superior transduction.
- Histone H3 acetylation on the AAV vector genome was characterized.
- Significant enhancement of transgene expression and therapeutic effects were confirmed in vivo.
Conclusions:
- The histone deacetylase inhibitor FR901228 effectively enhances rAAV-mediated gene expression in cancer cells.
- Enhanced transduction is likely due to improved transgene expression, potentially linked to histone acetylation of the viral genome.
- FR901228 shows promise for improving the utility of rAAV-based cancer gene therapy strategies.
