114 research outputs found
International Journal of Molecular Sciences / MicroRNAs associated with the efficacy of photodynamic therapy in biliary tract cancer cell lines
No full textPhotodynamic therapy (PDT) is a palliative treatment option for unresectable hilar biliary tract cancer (BTC) showing a considerable benefit for survival and quality of life with few side effects. Currently, factors determining the cellular response of BTC cells towards PDT are unknown. Due to their multifaceted nature, microRNAs (miRs) are a promising analyte to investigate the cellular mechanisms following PDT. For two photosensitizers, Photofrin® and Foscan®, the phototoxicity was investigated in eight BTC cell lines. Each cell line (untreated) was profiled for expression of n = 754 miRs using TaqMan® Array Human MicroRNA Cards. Statistical analysis and bioinformatic tools were used to identify miRs associated with PDT efficiency and their putative targets, respectively. Twenty miRs correlated significantly with either high or low PDT efficiency. PDT was particularly effective in cells with high levels of clustered miRs 25-93*-106b and (in case of miR-106b) a phenotype characterized by high expression of the mesenchymal marker vimentin and high proliferation (cyclinD1 and Ki67 expression). Insensitivity towards PDT was associated with high miR-200 family expression and (for miR-cluster 200a/b-429) expression of differentiation markers Ck19 and Ck8/18. Predicted and validated downstream targets indicate plausible involvement of miRs 20a*, 25, 93*, 130a, 141, 200a, 200c and 203 in response mechanisms to PDT, suggesting that targeting these miRs could improve susceptibility to PDT in insensitive cell lines. Taken together, the miRNome pattern may provide a novel tool for predicting the efficiency of PDT and—following appropriate functional verification—may subsequently allow for optimization of the PDT protocol.Andrej Wagner, Christian Mayr, Doris Bach, Romana Illig, Kristjan Plaetzer, Frieder Berr, Martin Pichler, Daniel Neureiter and Tobias Kiesslic
Dietary N-3 polyunsaturated fatty acids decrease biliary cholesterol saturation in gallstone disease
No full textBecause fatty acid composition of biliary phospholipids influences cholesterol secretion into bile, we investigated whether replacement of n-1 monounsaturated or n-6 polyunsaturated fatty acids with n-3 polyunsaturated fatty acids in biliary phosphatidylcholines reduces supersaturation with cholesterol and prevents precipitation of cholesterol crystals in bile of gallstone patients. Seven patients with radiolucent gallstones in functioning gallbladders were studied before (control) and after 5 wk of dietary supplementation with marine fish oil (11.3 gm/day = 3.75 gm n-3 polyunsaturated fatty acids/day). Duodenal bile was collected for analysis during intravenous infusion of cholecystokinin. Gallbladder emptying in response to cholecystokinin was comparable before and during intake of n-3 polyunsaturated fatty acids. Intake of n-3 polyunsaturated fatty acids increased (p < 0.001) the fractions of eicosapentaenoic and docosahexaenoic acids and decreased the fractions of linoleic (p < 0.001) and arachidonic acids (p < 0.02) in biliary phospholipids. Concomitantly, the molar ratio of cholesterol to phospholipids decreased (-19%; p < 0.05). As a consequence, the cholesterol saturation index was reduced by -25% (p = 0.01), from 1.60 ± 0.44 to 1.24 ± 0.38. However, in vitro nucleation time of duodenal bile was not prolonged. The decrease in cholesterol saturation was not sufficient to prevent nucleation of cholesterol crystals in bile of gallstone patients. In conclusion, our data suggest that cholesterol saturation can be influenced by the fatty acid composition of the phosphatidylcholines secreted in bile
Endoscopic Detection and Analysis of Mucosal Neoplastic Lesions: Enhanced Imaging and Tumor Morphology
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