Ellagic Acid: Cytodifferentiating and Antiproliferative Effects In Human Prostatic Cancer Cell Lines

Background: Recently, increasing attention has been given to neuroendocrine differentiation (NED) of Prostate Cancer and its diagnostic, prognostic and therapeutic potential. During multistep carcinogenesis, cytodifferentiation of malignant/premalignant cells into more mature or normal-like cells, has become an attractive modality of treatment and promises to be a less toxic and a more specific targeting strategy than conventional chemotherapy. In this study we investigated the capacity of a polyphenol, ellagic acid (EA), to induce differentiation of two prostate cancer cell lines: LnCap and DU145.Methods: NED markers, Chromogranin A (CgA) and p75NGFR levels were evaluated by immunocytochemistry. DNA methyltransferase- 1 (DNMT-1) and phospho-Rb (p-Rb) expression were evaluated by western blotting. Akt activation was evaluated by ELISA. Finally the ability of EA to induce DNA damage in cancer cells was examined using the COMET assay.Results: Treatment with EA significantly reduced CgA levels and increased p75NGFR expression. Moreover p-Rb, DNMT-1 levels and Akt activation/phosphorylation were decreased. EA treatment induced, in a dose-dependent manner, a marked increase in DNA damage, both in LnCap and DU145 cell lines.Conclusions: The results of this study demonstrate that EA treatment represents a new approach and highly effective strategy in reducing carcinogenesis. Therefore, EA may be considered in a promising new class of cancer therapeutic agent, with both antiproliferative and pro-differentiation properties.