The histone deacetylase inhibitor FK228 given prior to adenovirus infection can boost infection in melanoma xenograft model systems.

A major limitation of adenovirus type 5-mediated cancer gene therapy is the inefficient infection of many cancer cells. Previously, we showed that treatment with low doses of the histone deacetylase inhibitor FK228 (FR901228, depsipeptide) increased coxsackie adenovirus receptor (CAR) levels, histone H3 acetylation, and adenovirus infection efficiencies as measured by viral transgene expression in cancer cell lines but not in cultured normal cells. To evaluate FK228 in vivo, the effects of FK228 therapy in athymic mice bearing LOX IMVI or UACC-62 human melanoma xenografts were examined.

The histone deacetylase inhibitor FK228 preferentially enhances adenovirus transgene expression in malignant cells.

Purpose: Efficient adenovirus infection requires coxsackie-adenovirus receptor (CAR) and alpha(v) integrin. Whereas many malignant cells express these proteins poorly, normal tissues, especially liver, express high levels and are susceptible to adenovirus infection. Our previous studies showed that treatment of cancer cell lines with low concentrations of the histone deacetylase inhibitor FK228 (FR901228, depsipeptide), a drug in Phase II clinical trials, before infection was associated with an increase in adenovirus transgene expression.

Histone deacetylase inhibitor FR901228 enhances adenovirus infection of hematopoietic cells.

Adenovirus infection of hematopoietic cells frequently requires high virus concentrations and long incubation times to obtain moderate infection levels because these cells have low levels of Coxsackie and adenovirus receptor (CAR) and alpha(v) integrin. The effect of treatment with FR901228 (depsipeptide), a histone deacetylase inhibitor in phase 2 clinical trials, was studied in K562 cells, granulocyte-colony-stimulating factor-mobilized peripheral blood mononuclear cells (PBMCs), and CD34+ peripheral blood stem cells (PBSCs). FR901228 increased CAR and alpha(v) integrin RNA levels and histone H3 acetylation.