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Omeprazole inhibits proliferation and modulates autophagy in pancreatic cancer cells.

Udelnow A, Kreyes A, Ellinger S, Landfester K, Walther P, Klapperstueck T, Wohlrab J, Henne-Bruns D, Knippschild U, Würl P - PLoS ONE (2011)

Bottom Line: Gene expression of the autophagy-related LC3 gene as well as of Bad, Mdr-1, Atg12 and the vATPase was analysed after treatment of cells with 5-fluorouracil and omeprazole and confirmed the above mentioned results.We hypothesise that omeprazole interacts with the regulatory functions of the vATPase without inhibiting its pump function.Since omeprazole use has already been established in clinical practice these results could lead to new clinical applications.

View Article: PubMed Central - PubMed

Affiliation: Department of General, Visceral and Transplantation Surgery, University Hospital of Ulm, Ulm, Germany.

ABSTRACT

Background: Omeprazole has recently been described as a modulator of tumour chemoresistance, although its underlying molecular mechanisms remain controversial. Since pancreatic tumours are highly chemoresistant, a logical step would be to investigate the pharmacodynamic, morphological and biochemical effects of omeprazole on pancreatic cancer cell lines.

Methodology/principal findings: Dose-effect curves of omeprazole, pantoprazole, gemcitabine, 5-fluorouracil and the combinations of omeprazole and 5-fluorouracil or gemcitabine were generated for the pancreatic cancer cell lines MiaPaCa-2, ASPC-1, Colo357, PancTu-1, Panc1 and Panc89. They revealed that omeprazole inhibited proliferation at probably non-toxic concentrations and reversed the hormesis phenomena of 5-fluorouracil. Electron microscopy showed that omeprazole led to accumulation of phagophores and early autophagosomes in ASPC-1 and MiaPaCa-2 cells. Signal changes indicating inhibited proliferation and programmed cell death were found by proton NMR spectroscopy of both cell lines when treated with omeprazole which was identified intracellularly. Omeprazole modulates the lysosomal transport pathway as shown by Western blot analysis of the expression of LAMP-1, Cathepsin-D and β-COP in lysosome- and Golgi complex containing cell fractions. Acridine orange staining revealed that the pump function of the vATPase was not specifically inhibited by omeprazole. Gene expression of the autophagy-related LC3 gene as well as of Bad, Mdr-1, Atg12 and the vATPase was analysed after treatment of cells with 5-fluorouracil and omeprazole and confirmed the above mentioned results.

Conclusions: We hypothesise that omeprazole interacts with the regulatory functions of the vATPase without inhibiting its pump function. A modulation of the lysosomal transport pathway and autophagy is caused in pancreatic cancer cells leading to programmed cell death. This may circumvent common resistance mechanisms of pancreatic cancer. Since omeprazole use has already been established in clinical practice these results could lead to new clinical applications.

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Simplified metabolic networks of ASPC-1 cells as determined by proton NMR spectroscopy.The ASPC-1 cell line is shown without and upon various treatment regimens (OMP, 5-FU or 5-FU+OMP combination). The nodes of this network symbolize metabolite signals, their colours correspond to relative signal intensity (when compared to an external standard) as indicated in the heatmap scale below. The signal intensity is linearly related to the intracellular concentration. The background of the nodes are left blank when the signal intensity is out of the range indicated by the heatmap scale. The lines between the boxes symbolize strongly simplified metabolic pathways. The colours of these lines indicate significant differences of the signal intensity ratios of the connected metabolites compared to the control group when orange (p<0.05), red lines indicate p<0.01. The most obvious changes is that the PC/Cho ratio is significantly lower in the OMP group compared to the control group. Upon 5-FU, the Cho/Acetate ratio decrease is the only significant change. In the 5-FU+OMP group, there are several significant changes, i.e.the FACH2/CH = CH ratio is significantly higher. Moreover, the Cho/Acetate ratio changed upon 5-FU+OMP as in the 5-FU group, but also the citrate/GSH ratio. The cellular biochemical effects involve mainly the fatty acid and phospholipid metabolism pointing to membrane anabolism. Abbreviations: Gln - glutamine, Ala - alanine, PC - phosphatidylcholine, Cho – Choline, Lac1+FACH2 - methyl group signal of lactate and methylene groups of the fatty acids, Lac2 - methylene group of lactate, CH = CH - protons of methin groups of unsaturated fatty acids.
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pone-0020143-g006: Simplified metabolic networks of ASPC-1 cells as determined by proton NMR spectroscopy.The ASPC-1 cell line is shown without and upon various treatment regimens (OMP, 5-FU or 5-FU+OMP combination). The nodes of this network symbolize metabolite signals, their colours correspond to relative signal intensity (when compared to an external standard) as indicated in the heatmap scale below. The signal intensity is linearly related to the intracellular concentration. The background of the nodes are left blank when the signal intensity is out of the range indicated by the heatmap scale. The lines between the boxes symbolize strongly simplified metabolic pathways. The colours of these lines indicate significant differences of the signal intensity ratios of the connected metabolites compared to the control group when orange (p<0.05), red lines indicate p<0.01. The most obvious changes is that the PC/Cho ratio is significantly lower in the OMP group compared to the control group. Upon 5-FU, the Cho/Acetate ratio decrease is the only significant change. In the 5-FU+OMP group, there are several significant changes, i.e.the FACH2/CH = CH ratio is significantly higher. Moreover, the Cho/Acetate ratio changed upon 5-FU+OMP as in the 5-FU group, but also the citrate/GSH ratio. The cellular biochemical effects involve mainly the fatty acid and phospholipid metabolism pointing to membrane anabolism. Abbreviations: Gln - glutamine, Ala - alanine, PC - phosphatidylcholine, Cho – Choline, Lac1+FACH2 - methyl group signal of lactate and methylene groups of the fatty acids, Lac2 - methylene group of lactate, CH = CH - protons of methin groups of unsaturated fatty acids.

Mentions: Although the determination of absolute intracellular concentrations by NMR spectroscopy is generally prone to systematic errors, the calculation of integral ratios of various signals may contain useful quantitative information on the metabolic pathways. These metabolic pathways are shown as a strongly simplified network for ASPC-1 cells in Figure 6 and MiaPaCa-2 cells in Figure 7. A line between two signals symbolises a metabolic pathway. The line is orange when the signal intensity ratio of the connected substances differs from the control with p<0.05 and red when p is below 0.01.


Omeprazole inhibits proliferation and modulates autophagy in pancreatic cancer cells.

Udelnow A, Kreyes A, Ellinger S, Landfester K, Walther P, Klapperstueck T, Wohlrab J, Henne-Bruns D, Knippschild U, Würl P - PLoS ONE (2011)

Simplified metabolic networks of ASPC-1 cells as determined by proton NMR spectroscopy.The ASPC-1 cell line is shown without and upon various treatment regimens (OMP, 5-FU or 5-FU+OMP combination). The nodes of this network symbolize metabolite signals, their colours correspond to relative signal intensity (when compared to an external standard) as indicated in the heatmap scale below. The signal intensity is linearly related to the intracellular concentration. The background of the nodes are left blank when the signal intensity is out of the range indicated by the heatmap scale. The lines between the boxes symbolize strongly simplified metabolic pathways. The colours of these lines indicate significant differences of the signal intensity ratios of the connected metabolites compared to the control group when orange (p<0.05), red lines indicate p<0.01. The most obvious changes is that the PC/Cho ratio is significantly lower in the OMP group compared to the control group. Upon 5-FU, the Cho/Acetate ratio decrease is the only significant change. In the 5-FU+OMP group, there are several significant changes, i.e.the FACH2/CH = CH ratio is significantly higher. Moreover, the Cho/Acetate ratio changed upon 5-FU+OMP as in the 5-FU group, but also the citrate/GSH ratio. The cellular biochemical effects involve mainly the fatty acid and phospholipid metabolism pointing to membrane anabolism. Abbreviations: Gln - glutamine, Ala - alanine, PC - phosphatidylcholine, Cho – Choline, Lac1+FACH2 - methyl group signal of lactate and methylene groups of the fatty acids, Lac2 - methylene group of lactate, CH = CH - protons of methin groups of unsaturated fatty acids.
© Copyright Policy
Related In: Results  -  Collection

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pone-0020143-g006: Simplified metabolic networks of ASPC-1 cells as determined by proton NMR spectroscopy.The ASPC-1 cell line is shown without and upon various treatment regimens (OMP, 5-FU or 5-FU+OMP combination). The nodes of this network symbolize metabolite signals, their colours correspond to relative signal intensity (when compared to an external standard) as indicated in the heatmap scale below. The signal intensity is linearly related to the intracellular concentration. The background of the nodes are left blank when the signal intensity is out of the range indicated by the heatmap scale. The lines between the boxes symbolize strongly simplified metabolic pathways. The colours of these lines indicate significant differences of the signal intensity ratios of the connected metabolites compared to the control group when orange (p<0.05), red lines indicate p<0.01. The most obvious changes is that the PC/Cho ratio is significantly lower in the OMP group compared to the control group. Upon 5-FU, the Cho/Acetate ratio decrease is the only significant change. In the 5-FU+OMP group, there are several significant changes, i.e.the FACH2/CH = CH ratio is significantly higher. Moreover, the Cho/Acetate ratio changed upon 5-FU+OMP as in the 5-FU group, but also the citrate/GSH ratio. The cellular biochemical effects involve mainly the fatty acid and phospholipid metabolism pointing to membrane anabolism. Abbreviations: Gln - glutamine, Ala - alanine, PC - phosphatidylcholine, Cho – Choline, Lac1+FACH2 - methyl group signal of lactate and methylene groups of the fatty acids, Lac2 - methylene group of lactate, CH = CH - protons of methin groups of unsaturated fatty acids.
Mentions: Although the determination of absolute intracellular concentrations by NMR spectroscopy is generally prone to systematic errors, the calculation of integral ratios of various signals may contain useful quantitative information on the metabolic pathways. These metabolic pathways are shown as a strongly simplified network for ASPC-1 cells in Figure 6 and MiaPaCa-2 cells in Figure 7. A line between two signals symbolises a metabolic pathway. The line is orange when the signal intensity ratio of the connected substances differs from the control with p<0.05 and red when p is below 0.01.

Bottom Line: Gene expression of the autophagy-related LC3 gene as well as of Bad, Mdr-1, Atg12 and the vATPase was analysed after treatment of cells with 5-fluorouracil and omeprazole and confirmed the above mentioned results.We hypothesise that omeprazole interacts with the regulatory functions of the vATPase without inhibiting its pump function.Since omeprazole use has already been established in clinical practice these results could lead to new clinical applications.

View Article: PubMed Central - PubMed

Affiliation: Department of General, Visceral and Transplantation Surgery, University Hospital of Ulm, Ulm, Germany.

ABSTRACT

Background: Omeprazole has recently been described as a modulator of tumour chemoresistance, although its underlying molecular mechanisms remain controversial. Since pancreatic tumours are highly chemoresistant, a logical step would be to investigate the pharmacodynamic, morphological and biochemical effects of omeprazole on pancreatic cancer cell lines.

Methodology/principal findings: Dose-effect curves of omeprazole, pantoprazole, gemcitabine, 5-fluorouracil and the combinations of omeprazole and 5-fluorouracil or gemcitabine were generated for the pancreatic cancer cell lines MiaPaCa-2, ASPC-1, Colo357, PancTu-1, Panc1 and Panc89. They revealed that omeprazole inhibited proliferation at probably non-toxic concentrations and reversed the hormesis phenomena of 5-fluorouracil. Electron microscopy showed that omeprazole led to accumulation of phagophores and early autophagosomes in ASPC-1 and MiaPaCa-2 cells. Signal changes indicating inhibited proliferation and programmed cell death were found by proton NMR spectroscopy of both cell lines when treated with omeprazole which was identified intracellularly. Omeprazole modulates the lysosomal transport pathway as shown by Western blot analysis of the expression of LAMP-1, Cathepsin-D and β-COP in lysosome- and Golgi complex containing cell fractions. Acridine orange staining revealed that the pump function of the vATPase was not specifically inhibited by omeprazole. Gene expression of the autophagy-related LC3 gene as well as of Bad, Mdr-1, Atg12 and the vATPase was analysed after treatment of cells with 5-fluorouracil and omeprazole and confirmed the above mentioned results.

Conclusions: We hypothesise that omeprazole interacts with the regulatory functions of the vATPase without inhibiting its pump function. A modulation of the lysosomal transport pathway and autophagy is caused in pancreatic cancer cells leading to programmed cell death. This may circumvent common resistance mechanisms of pancreatic cancer. Since omeprazole use has already been established in clinical practice these results could lead to new clinical applications.

Show MeSH
Related in: MedlinePlus