Individualization of therapies for patients with advanced differentiated thyroid cancers

The Cross-Talk between Polyphenols and the Target Enzymes Related to Oxidative Stress-Induced Thyroid Cancer

The most serious hallmark step of carcinogenesis is oxidative stress, which induces cell DNA damage. Although in normal conditions ROS are important second messengers, in pathological conditions such as cancer, due to imbalanced redox enzyme expression, oxidative stress can occur. Recent studies with firmly established evidence suggest an interdependence between oxidative stress and thyroid cancer based on thyroid hormone synthesis. Indeed, a reduced antioxidant defense system might play a part in several steps of progression in thyroid cancer. Based on studies that have been conducted previously, future drug designs for targeting enzymatic ROS sources, as a single agent or in combination, have to be tested. Polyphenols represent the potential for modulating biological events in thyroid cancer, including antioxidative activity. Targeting enzymatic ROS sources, without affecting the physiological redox state, might be an important purpose. As regards the underlying chemopreventive mechanisms of natural compounds that have been discussed in other cancer models, the confirmation of the influence of polyphenols on thyroid cancer is inconclusive and rarely available. Therefore, there is a need for further scientific investigations into the features of the antioxidative effects of polyphenols on thyroid cancer. The current review illustrates the association between some polyphenols and the key enzymes that take place in oxidation reactions in developing thyroid cancer cells. This review gives the main points of the enzymatic ROS sources act and redox signaling in normal physiological or pathological contexts and supplies a survey of the currently available modulators of TPO, LOX, NOX, DUOX, Nrf2, and LPO derived from polyphenols.

Antioxidant and antigrowth action of peracetylated oleuropein in thyroid cancer cells

The olive tree phenolic component oleuropein (OLE) and its derivatives have shown many biological properties, thus representing promising novel therapeutics for the treatment of several diseases, including neoplasia. In this study, we evaluated the activities of OLE and its peracetylated derivative (peracetylated oleuropein, Ac-OLE) against two thyroid tumor cell lines that host genotypic alterations detected in human papillary thyroid cancer. TPC-1 and BCPAP cells were treated with OLE and Ac-OLE, and the effects on viability were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cell counting, and trypan blue exclusion assays. Antioxidant effects were analyzed by measuring the reactive oxygen species (ROS) in basal conditions and after treatment with hydrogen peroxide (H2O2). Activity of MAP kinase and PI3K-Akt signaling pathways was evaluated by examining the levels of phosphorylated ERK and Akt by western blot. We found that OLE significantly inhibited the proliferation of both cell lines. This effect was paralleled by a reduction of basal phospho-Akt and phospho-ERK levels and H2O2-induced ROS levels. A stronger effect was elicited by Ac-OLE either in inhibiting cell growth or as an antioxidant, in particular on BCPAP cells. Our results demonstrate that OLE and especially Ac-OLE inhibit in vitro thyroid cancer cell proliferation acting on growth-promoting signal pathways, as well as exerting antioxidant effects. Further studies will reveal the potential application as novel targeted therapeutics in thyroid cancer.