Molecular analysis of the apoptotic effects of BPA in acute myeloid leukemia cells.

BACKGROUND: BPA (bisphenol A or 2,2-bis(4-hydroxy-phenol)propane) is present in the manufacture of polycarbonate plastic and epoxy resins, which can be used in impact-resistant safety equipment and baby bottles, as protective coatings inside metal food containers, and as composites and sealants in dentistry. Recently, attention has focused on the estrogen-like and carcinogenic adverse effects of BPA. Thus, it is necessary to investigate the cytotoxicity and apoptosis-inducing activity of this compound. METHODS: Cell cycle, apoptosis and differentiation analyses; western blots. RESULTS: BPA is able to induce cell cycle arrest and apoptosis in three different acute myeloid leukemias. Although some granulocytic differentiation concomitantly occurred in NB4 cells upon BPA treatment, the major action was the induction of apoptosis. BPA mediated apoptosis was caspase dependent and occurred by activation of extrinsic and intrinsic cell death pathways modulating both FAS and TRAIL and by inducing BAD phosphorylation in NB4 cells. Finally, also non genomic actions such as the early decrease of both ERK and AKT phosphorylation were induced by BPA thus indicating that a complex intersection of regulations occur for the apoptotic action of BPA. CONCLUSION: BPA is able to induce apoptosis in leukemia cells via caspase activation and involvement of both intrinsic and extrinsic pathways of apoptosis.

Feijoa sellowiana derived natural Flavone exerts anti-cancer action displaying HDAC inhibitory activities.

Curative properties of some medicinal plants such as the Feijoa sellowiana Bert. (Myrtaceae), have been often claimed, although the corresponding molecular mechanism(s) remain elusive. We report here that the Feijoa acetonic extract exerts anti-cancer activities on solid and hematological cancer cells. Feijoa extract did not show toxic effects on normal myeloid progenitors thus displaying a tumor-selective activity. In the Feijoa acetonic extract, fractionation and subsequent purification and analyses identified Flavone as the active component. Flavone induces apoptosis which is accompanied by caspase activation and p16, p21 and TRAIL over-expression in human myeloid leukemia cells. Use of ex vivo myeloid leukemia patients blasts confirms that both the full acetonic Feijoa extract and its derived Flavone are able to induce apoptosis. In both cell lines and myeloid leukemia patients blasts the apoptotic activity of Feijoa extract and Flavone is accompanied by increase of histone and non-histone acetylation levels and by HDAC inhibition. Our findings show for the first time that the Feijoa apoptotic active principle is the Flavone and that this activity correlates with the induction of HDAC inhibition, supporting the hypothesis of its epigenetic pro-apoptotic regulation in cancer systems.