Apoptosis induced by Berberine on thyroid cancer cells as investigated by Delayed Luminescence spectroscopy

Now a day the possibility of using non-invasive diagnostic tool in clinical survey has a growing interest. In this respect detection of Delayed Luminescence (DL), that is the prolonged (usually in a microsecond to second time range) ultra-weak emission of optical photons from a biological sample after the illumination source is switched off, makes it possible to acquire immediate information on biological activities non–invasively. As a matter of fact the possibility of discriminating between tumor and normal cells, or to assess the pro-apoptotic capacity of combined cancer treatments was previously pointed out. In this work correlation between apoptosis and UVA induced DL from tumor thyroid cell lines was investigated. More precisely the effects of Berberine, an alkaloid that has been reported to have anticancer activities, on two thyroid human cancer cell lines was studied. The human follicular (FTC-133) and the anaplastic (8305C) cell lines were considered, as representatives of two aggressive types of thyroid cancer, poorly differentiated and dedifferentiated, respectively. The results show that Berberine is able to arrest cell cycle and activate apoptotic pathway as shown in both cell lines by DNA fragmentation, caspase-3 cleavage, p53 and p27 protein over-expression. In parallel, changes in DL spectral components after Berberine treatment support the hypothesis that DL from human cells originates mainly from mitochondria, since Berberine acts especially at the mitochondrial level. In addition the strong decrease of DL blue component for both cell lines may be a hallmark of induced apoptosis, while different response in the red spectral range may be ascribed to a different iron homeostasis in the two cell lines.