PCP is a phenol derivative that has been extensively used as a wood preservative, insecticide and fungicide [7] and [8]. PCP undergoes oxidative dechlorination to form tetrachlorohydroquinone (TCHQ), a more toxic metabolite of PCP [9] and [10]. PCP toxicity seems to be related mainly to TCHQ-mediated uncoupling of oxidative phosphorylation and the generation of reactive oxygen species (ROS) in mitochondria [11] and [12]. Although it has been shown to promote tumour growth [13], studies suggesting that this compound and its derivative can induce cell death are sparse [14] and [15]. This work was initiated by our preliminary

observations that PCP induces inhibition of CK2 in an ATP-competitive manner. The aim of this study was find more to contribute to the knowledge of the effects of PCP in human pancreatic cancer cells and to shed light on the intracellular signalling pathways involved in PCP-induced cytotoxicity. To our knowledge, this is the first contribution on the characterization of PCP at the molecular level in this type of cells. Protein kinase activity measurements of recombinant CK2α and CK2α2β2 were performed in 40 μl of a reaction mixture containing varying concentrations of C11, PCP or dimethylallylamine (DMA), as indicated in the figure legends, 25 mM Tris/HCl pH 7.5,

5 mM NaCl for CK2α and 150 mM for CK2α2β2, 18.75 mM MgCl2, 0.5 mM DTT, 190 μM synthetic peptide RRRDDDSDDD (KinaseDetect, Odense, Denmark), 125 μM ATP and 10 μCi [γ-32P-ATP] (3000 Ci/mmol, selleck products Hartmann Analytic, Braunschweig, Germany). After incubation at 30 °C for 10 min, the reactions were stopped on ice and samples were spotted onto a grade P81 cellulose paper (WhatmanTM, GE Healthcare, Brøndby, Denmark). Radioactivity incorporated into the substrate target was determined by scintillation counting in a 1450 MicroBeta2 Plate counter (PerkinElmer, Waltham, MA, USA). The pancreatic ductal adenocarcinoma cell lines Panc-1 and MIA PaCa-2 (ATCC,

Rockville, MD, USA) were cultured according to the manufacturer’s guidelines and maintained at 37 °C in G protein-coupled receptor kinase a humidified atmosphere supplemented with 5% CO2. Cells were treated with C11 (NCI, Bethesda, MD, USA), pentachlorophenol (PCP, AccuStandard, New Haven, CT, USA), dimethylallylamine (DMA, Chemical point, Deisenhofen, Germany) and TNFα (R&D Systems, Abingdon, United Kingdom) as indicated in the figure legends. DMSO (Sigma-Aldrich, Schnelldorf, Germany) was used in all control experiments at a final concentration not exceeding 0.2% (v/v). Cell viability was determined by the WST-1 assay (Roche, Mannheim, Germany) in a 96-well plate. 24 h after seeding, cells were treated with various concentrations of C11, PCP and DMA, respectively, for 48 h. WST-1 reagent was added to the cells according to the manufacturer’s instructions and cell viability was determined 2 h later in a VersaMax ELISA microplate reader (Molecular Devices, CA, USA).