Vorinostat, a histone deacetylase inhibitor, as a potential novel treatment for psoriasis.

BACKGROUND Psoriasis is characterized by aberrant activation of several pro-inflammatory circuits as well as abnormal hyperproliferation and dysregulated apoptosis of keratinocytes (KCs). Most currently available therapeutic options primarily target psoriasis-associated immunological defects rather than epidermal abnormalities. OBJECTIVE To investigate the efficacy of the histone deacetylase (HDAC) inhibitor, Vorinostat, in targeting hyperproliferation and impaired apoptosis in psoriatic skin. METHODS Vorinostat effect was investigated in primary KCs cell cultures using cell cycle analysis by flow cytometry, apoptosis assays (Annexin V-FICH and caspase - 3/7) and antibody arrays, qRT-PCR and immunohistochemistry. Vorinostat impact on clinical manifestations of psoriasis was investigated in a chimeric mouse model. RESULTS Vorinostat was found to inhibit KCs proliferation and to induce their differentiation and apoptosis. Using a chimeric mouse model, vorinostat was found to result in marked attenuation of a psoriasiform phenotype with a significant decrease in epidermal thickness and inhibition of epidermal proliferation. CONCLUSIONS Our results support the notion that vorinostat, a prototypic HDAC inhibitor, may be of potential use in the treatment of psoriasis and other hyperproliferative skin disorders.