Olive oil phenols as potential source of chemopreventive and therapeutic agents against bladder cancer

The consumption of extra virgin olive oil (EVOO), a common dietary habit of the mediterranean people, seems to be related to a lower incidence of certain types of cancer including bladder neoplasm. Metastases are the major cause of bladder cancer-related deaths and targeting cell motility has been proposed as a therapeutic strategy to prevent cancer spread. This study aim to investigate the potential anti-metastatic and antiproliferative effect of total phenols extracted from EVOO against human transitional bladder carcinoma cell lines. Our results show that EVOO extract can significantly inhibit the proliferation and motility of T24 bladder cells in a dose-dependent manner. Furthermore the enzymatic activity of MMP-2 was inhibited at non-toxic EVOO extract doses in T24 cells. The qRT-PCR revealed a decrease of the MMP-2 expression, and a simultaneous increase of the TIMPs gene expression. The cell cycle analysis of two bladder cancer cell lines (T24 and 5637) after EVOO-E treatment show a marked growth arrest prior to mitosis in the G2/M phase for both the cell lines with the subsequent induction of apoptosis only in T24 cells. Finally we evaluated the ability of EVOOE to chemosensitize T24 to the cytotoxic action of common used chemoterapics. Interestingly the simultaneous treatment of Paclitaxel and EVOOE strongly increase the apoptotic cell death at every of the tested concentration if compared to the drug alone. Our results may support the epidemiological evidences which link olive oil consumption to health benefits and may represent a starting point for the development of new anticancer strategies.