We show that treatment with non-toxic doses of zinc in association to the ionophore compound pyrrolidine dithiocarbamate (PDTC) inhibits p53-/- pancreatic cancer cell growth much more efficiently than gemcitabine, the gold standard chemotherapeutic agent for pancreatic cancer. Both the metal chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine and the radical scavenger N-acetyl-l-cysteine are able to recover cell growth inhibition by Zn/PDTC, demonstrating that this effect depends on the increased levels of intracellular zinc and of reactive oxygen species (ROS). Zn/PDTC treatment induces a strong apoptotic cell death that is associated to ROS-dependent nuclear translocation of the mitochondrial factor AIF, but not to the regulation of apoptotic genes and caspase activation. Primary fibroblasts are more resistant than pancreatic cancer cells to Zn/PDTC treatment and exhibit a lower basal and Zn/PDTC-induced enhancement of intracellular zinc. We show that Zn/PDTC induces p53 proteasomal degradation and that the proteasome inhibitor MG132 further increases fibroblast growth inhibition by Zn/PDTC, suggesting that p53 degradation plays an important role in fibroblast resistance to Zn/PDTC. © 2008 Elsevier B.V. All rights reserved.
Donadelli, M., Dalla Pozza, E., Scupoli, M. T., Costanzo, C., Scarpa, A., & Palmieri, M. (2009). Intracellular zinc increase inhibits p53-/- pancreatic adenocarcinoma cell growth by ROS/AIF-mediated apoptosis. Biochimica et Biophysica Acta - Molecular Cell Research, 1793(2), 273–280. https://doi.org/10.1016/j.bbamcr.2008.09.010