title: Inhibition of histone deacetylation and DNA methylation improves gene expression mediated by the adeno-associated virus/phage in cancer cells.
abstract: Bacteriophage (phage), viruses that infect bacteria only, have become promising vectors for targeted systemic delivery of genes to cancer, although, with poor efficiency. We previously designed an improved phage vector by incorporating cis genetic elements of adeno-associated virus (AAV). This novel AAV/phage hybrid (AAVP) specifically targeted systemic delivery of therapeutic genes into tumors. To advance the AAVP vector, we recently introduced the stress-inducible Grp78 tumor specific promoter and found that this dual tumor-targeted AAVP provides persistent gene expression, over time, in cancer cells compared to silenced gene expression from the CMV promoter in the parental AAVP. Herein, we investigated the effect of histone deacetylation and DNA methylation on AAVP-mediated gene expression in cancer cells and explored the effect of cell confluence state on AAVP gene expression efficacy. Using a combination of AAVP expressing the GFP reporter gene, flow cytometry, inhibitors of histone deacetylation, and DNA methylation, we have demonstrated that histone deacetylation and DNA methylation are associated with silencing of gene expression from the CMV promoter in the parental AAVP. Importantly, inhibitors of histone deacetylases boost gene expression in cancer cells from the Grp78 promoter in the dual tumor-targeted AAVP. However, cell confluence had no effect on AAVP-guided gene expression. Our findings prove that combination of histone deacetylase inhibitor drugs with the Grp78 promoter is an effective approach to improve AAVP-mediated gene expression in cancer cells and should be considered for AAVP-based clinical cancer gene therapy.
authors.affiliation: Phage Therapy Group, Department of Medicine, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, UK. a.hajitou@imperial.ac.uk.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Kia
authors.forename: Teerapong
authors.initials: T
authors.lastname: Yata
authors.forename: Nabil
authors.initials: N
authors.lastname: Hajji
authors.forename: Amin
authors.initials: A
authors.lastname: Hajitou
mesh_terms: D000107:Acetylation; D000818:Animals; D001435:Bacteriophages / Q000235:genetics*; D045744:Cell Line, Tumor; D019175:DNA Methylation; D004279:DNA, Viral / Q000378:metabolism*; D000229:Dependovirus / Q000235:genetics*; D000091342:Endoplasmic Reticulum Chaperone BiP; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D015967:Gene Expression Regulation, Viral; D020868:Gene Silencing; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006657:Histones / Q000378:metabolism*; D006801:Humans; D011401:Promoter Regions, Genetic; D011499:Protein Processing, Post-Translational; D051381:Rats; D011995:Recombination, Genetic
chemical_list: D004279:DNA, Viral; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006657:Histones; D049452:Green Fluorescent Proteins