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Statins are widely used for the treatment of hypercholesterolemia. However, their inhibitory action on HMG-CoA reductase also results in the depletion of intermediate biosynthetic products, which importantly contribute to cell proliferation. The aim of the present study was to compare the effects of the individual commercially available statins on experimental pancreatic cancer. The in vitro effects of individual statins (pravastatin, atorvastatin, simvastatin, lovastatin, cerivastatin, rosuvastatin and fluvastatin) on the viability of human pancreatic cancer were evaluated in CAPAN-2, BxPc-3 and MiaPaCa-2 cell lines. The in vivo experiments were performed on nude mice xenotransplanted with CAPAN-2 cells. The mice received oral treatments either with a placebo, or with the statins mentioned earlier in a daily dose corresponding to a hypocholesterolemic dose in humans. The effect of these statins on the intracellular Ras protein, trafficking in MiaPaCa-2 transfected cells, was also investigated. Substantial differences in the tumor-suppressive effects of all statins were detected in both in vitro and in vivo experiments. While simvastatin exerted the highest tumor-suppressive effects in vitro, rosuvastatin (p 5 0.002), cerivastatin (p 5 0.002) and fluvastatin (p 5 0.009) were the most potent compounds in an animal model. All statins (except pravastatin) inhibited intracellular Ras protein translocation. In summary, substantial tumor-suppressive effects of various statins on the progression of experimental pancreatic adenocarcinoma were demonstrated, with marked differences among individual statins. These results support greatly the potential of statins for the chemoadjuvant treatment of pancreatic cancer. ' 2007 Wiley-Liss, Inc.

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Annexin A1 (ANXA1) is the first characterized member of the annexins superfamily. It binds the cellular membrane phospholipids in Ca(2+) regulated manner. Annexin A1 has been found in several tissues and many physiological roles as hormones secretion, vesiculation, inflammatory response, apoptosis and differentiation have been shown. Its subcellular localization and binding with many partner proteins are altered accordingly with its physiological role. The Annexin A1 membrane localization is crucial for binding to receptors, suggesting a paracrine and juxtacrine extracellular action. Annexin A1 is subjected to several post-translational modifications. In particular the protein is phosphorylated on several residues both on the N-terminal functional domain and on the C-terminus core. Different kinases have been identified as responsible for the phosphorylation status of selective residues. The specific change in the phosphorylation status on the different sites alters ANXA1 localization, binding properties and functions. This review shows the physiological relevance of the ANXA1 phosphorylation leading to the conclusion that numerous and different roles of Annexin A1 could be associated with different phosphorylations to alter not only intracellular localization and bindings to its partners but also the extracellular receptor interactions.

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Statins, besides being powerful cholesterol-lowering drugs, also exert potent anti-proliferative activities. However, their anti-cancer efficacy differs among the individual statins. Thus, the aim of this study was to identify the biological pathways affected by individual statins in an in vitro model of human pancreatic cancer. The study was performed on a human pancreatic cancer cell line MiaPaCa-2, exposed to all commercially available statins (12 μM, 24 h exposure). DNA microarray analysis was used to determine changes in the gene expression of treated cells. Intracellular concentrations of individual statins were measured by UPLC (ultra performance liquid chromatography)-HRMS (high resolution mass spectrometer). Large differences in the gene transcription profiles of pancreatic cancer cells exposed to various statins were observed; cerivastatin, pitavastatin, and simvastatin being the most efficient modulators of expression of genes involved namely in the mevalonate pathway, cell cycle regulation, DNA replication, apoptosis and cytoskeleton signaling. Marked differences in the intracellular concentrations of individual statins in pancreatic cancer cells were found (>11 times lower concentration of rosuvastatin compared to lovastatin), which may contribute to inter-individual variability in their anti-cancer effects. In conclusion, individual statins exert different gene expression modulating effects in treated pancreatic cancer cells. These effects may be partially caused by large differences in their bioavailability. We report large differences in gene transcription profiles of pancreatic cancer cells exposed to various statins. These data correlate to some extent with the intracellular concentrations of statins, and may explain the inter-individual variability in the anti-cancer effects of statins.

BackgroundStatins (HMG-CoA reductase inhibitors) represent a major class of compounds for the treatment of hypercholesterolemia due to their ability to inhibit de novo cholesterol synthesis. In addition to their hypolipidemic effects, chemoprotective properties have been attributed to statins as well. These effects involve multiple mechanisms, which, however, are not known in detail. The aim of our study was to assess in non-malignant as well as cancer cells the impact of simvastatin on the amount of cytosolic lipid droplets (LDs) implicated in many biological processes including proliferation, inflammation, carcinogenesis, apoptosis, necrosis or growth arrest.MethodsHuman embryonic kidney cells HEK-293T and human pancreatic cancer cells MiaPaCa-2 were treated with simvastatin (6 and 12 μM) for 24 and 48 hours respectively. Neutral lipid probe Nile Red was used for detection of LDs by fluorescence microscopy. Cellular cholesterol content was determined by HPLC. Changes in expression of genes related to lipid metabolism in simvastatin-treated MiaPaCa-2 cells were examined by DNA microarray analysis. Validation of gene expression changes was performed using quantitative RT-PCR.ResultsThe treatment of the cells with simvastatin increased their intracellular content of LDs in both non-malignant as well as cancer cells, partially due to the uptake of cholesterol and triacylglyceroles from medium; but in particular, due to enhanced synthesis of triacylglyceroles as proved by significant overexpression of genes related to de novo synthesis of triacylglyceroles and phospholipids. In addition, simvastatin also markedly influenced expression of genes directly affecting cell proliferation and signaling.ConclusionsSimvastatin treatment led to accumulation of cytosolic LDs within the examined cells, a phenomenon which might contribute to the antiproliferative effects of statins.