Histone deacetylase activity in peripheral blood of patients with malignant pleural mesothelioma.

e21165 Background: Histone deacetylase (HDAC) modulates gene expression through the deacetylation of lysine residues on histone proteins and acts transcriptional repressors of genes. HDAC is currently the focus of new target for cancer therapy, because of its role in cell cycling, apoptosis and differentiation. There is an increasing amount of preclinical data on the effectiveness of HDAC inhibition in mesothelioma cell lines and mouse xenograft models, but no clinical data on HDAC activity in malignant pleural mesothelioma (MPM) has been published. Methods: We evaluated HDAC activity in the peripheral blood mononuclear cells (1x105) of patients with MPM (n=37) and healthy volunteers without asbestos exposure (n=25) using HDAC fluorometric assay. Results: The level of HDAC activity was significantly higher in patients with MPM than that in normal subjects (p=0.0008, MPM=134,778 ± 84,357 arbitrary fluorescence units, normal subject=64,314 ± 63,070 AFU) The median HDAC activity in epithelioid subtype (n=26)...