Long-term antiepileptic treatment with histone deacetylase inhibitors may reduce the risk of prostate cancer.

Various antiepileptic drugs such as valproic acid, carbamazepine, oxcarbazepine, lamotrigine and levetiracetam are known to exert histone deacetylase inhibitory (HDACi) properties, which can modify aberrantly silenced gene expression by an epigenetic mechanism. This study was initiated to examine a potential beneficial effect of these drugs on prostate cancer (PC) development. The prostate-specific antigen (PSA) levels of 106 patients under long-term treatment with antiepileptic drugs and known HDACi properties were examined. PSA represents a hallmark in the early detection of PC, and its levels may predict an invasive disease in subsequent years. For in-vitro experiments, the PC cell line LNCaP was treated with HDACi drugs; subsequently, PSA and further PC markers were assessed. When men over 50 years of age were treated with HDACi drugs they had lower age-corrected PSA levels compared with control groups, according to the following ranking: valproic acid>levetiracetam>carbamazepine/oxcarbazepine>lamotrigine. Furthermore, there was a correlation between PSA reduction and the number of HDACi drugs within the medication, lending credence to the idea that a synergistic effect might be possible. Moreover, in vitro, HDACi drugs decrease PSA on mRNA and protein levels and exhibit further oncoprotective properties.The fact that HDACi drugs exert antiproliferative effects on neoplastic cells in vitro and in vivo, which are paralleled by expression alterations of aberrantly regulated genes, underlines the potential therapeutic value of HDACi drugs. These data suggest that long-term HDACi treatment can positively influence the characteristically slow transformation of tumour precursor cells in the prostate and may thus reduce a patient's risk of developing PC.