Box-Whisker plots of lysosomal acidity quantified by AO fluorescence microscopy and image analysis.

<p>Acridine Orange was added to living untreated ASPC-1 and MiaPaCa-2 cells and cells treated with 5-FU, OMP or the combination of both for 30 minutes or 24 hours. Microscopical life images were taken at 525 nm (green) and 650 nm (red) to detect changes in the lysosomal pH value (three images per plate, three plates per group). The red to green fluorescence ratio of the lysosomes of treated cells were compared to the control groups by the Mann-Whitney-U-test. Significant differences compared to control are marked by *. In ASPC-1 cells, after 30 min of treatment, intralysosomal acidity increased upon treatment with OMP (p:0.0051) and 5-FU+OMP (p<0.0001). After 24 hours, the acidity is increased upon all treatment regimens (5-FU - p:0.0002; OMP - p<0.00001; OMP+5-FU - p:0.037). In MiaPaCa-2 cells the acidity is elevated after 30 min upon 5-FU (p:0.005) and decreased after treatment with OMP (p:0.037), 5-FU (p:0.00026) and 5-FU+OMP (p:0.011) after 24 hours.</p

Identification of substances from a proton NMR spectrum of viable untreated MiaPaCa-2 cells.

<p>The cells were harvested from monolayer culture, kept and measured at 20°C. Measurement were performed by a 600 MHz Bruker spectrometer. For better visibility the part of the spectrum showing the protons of aliphatic groups is splitted into 2 parts - A and B. (A). aliphatic part I. The methyl and β- and γ- methylene groups of various fatty acids and amino acids are visible. In addition, isopropanol and tetrachlorethan (the external concentration standard) occured as pollutions. (B) Aliphatic part II. Phospholipid metabolites and the α-methylene groups of amino acids and lactate are visible. (C) Formula of OMP with numbering of the respective protons. The methyl groups (1–3, 9) and the methyl group (4) are covered by other metabolites in the aliphatic parts of the spectrum. In contrast, the aromatic protons are visible (H5, H8, H10). (D) Overlay of the aromatic parts of different spectra for intracellular identification of OMP. The singulet of the H5 proton and the dublets of the H8 and H10 protons can be identified when the medium and the cell spectra are compared to those without OMP treatment. Abbreviations: His - histidine, Tyr - tyrosine, Phe – phenylalanine, Leu, Ile, Val - Leucine, Isoleucine, Valine. Ala - Alanine. Glu - Glutamate, Gln – Glutamine, PC - phosphatidylcholine, Cho - Choline, GPC – glycerophosphocholine, Tau – taurine, Scyllo - scylloinositole.</p

Detection of growth-stimulatory effects of 5-FU and GEM in lower doses.

<p>Significant elevations of cell counts compared to the control groups could be observed upon 5-FU in ASPC-1 (at 0.5 µg/ml 5-FU), Panc-1 (at 0.5 and 1 µg/ml 5-FU) and PancTu-1 (at 0.125 and 0.25 µg/ml) cells. In contrast, no hormesis could be observed upon GEM.</p><p>Abbreviations: c-concentration, fu-unaffected fraction (cell count related to control).</p

Gene expression analysis of membranal transport and apoptosis relevant genes in ASPC-1 cells.

<p>Quantification of mRNAs in ASPC-1 cells untreated or treated with OMP 80 µg/ml, 5-FU 5 µg/ml or the combination of both was performed at different time points throughout 24 hours, and the means of three replicates are shown for every time point. The stars indicate significant differences after 24 hours compared to control. The pro-apoptotic bad-mRNA was upregulated after 5-FU- and 5-FU+OMP-treatment. The antiapoptotic bcl-2 mRNA was downregulated by 5-FU and bcl-XL by 5-FU+OMP. OMP led to downregulation of bad and survivin and to upregulation of the mdr-1 mRNA.</p

Analysis of MiaPaCa-2 cell organelles after ultracentrifugation.

<p>(A) Overlay of the proton NMR spectrum fragments of the following suspensions (from top to down): untreated first (lysosomal) cell fraction after ultracentrifgation and one washing (F1*), iodixanole (Optiprep) suspension, lower (F3), middle (F2) and upper fraction (F1) of the ultracentrifugates after two washings. The chemical shifts of the spectra were calibrated to the Choline/Phosphatidylcholine (Cho/PC) signal. Apart from iodixanol, we could identify the PUFA groups (methylene groups situated between two CH = CH groups), Cho/PC and glycerophosphocholine (GPC) in F1* and F1–3. Furthermore we observed lactate and the methylene groups of fatty acids (at 1.3 ppm), citrate (at 2.55 and 2.7 ppm) and phosphoethanolamine (at 3.1 ppm) in the F1* but not in the F1–F3 groups.. (B) Western blot analysis of LAMP-1, a late endosome marker, which was nearly identically distributed over the first two fractions compared to Cathepsin-D, in the controle group, but ocurred only in the first fraction in the OMP treated group. β-COP as an indicator of the Golgi-complex, is found strongly in the lower fraction in the control group, but very weakly in the OMP treated group. Cathepsin - D, an early endosome marker, which can be found in the upper and middle fraction of the control group, but regarding the OMP group, it was only found in the first one. (E) Overlay of NMR spectra of all fractions of control and OMP. The most relevant difference is the weaning of the GPC signal after OMP treatment in the 1st fraction after only 6 hours.</p

Gene expression analysis of membranal transport and apoptosis relevant genes in MiaPaCa-2 cells.

<p>mRNA quantification in MiaPaCa-2 cells untreated or treated with OMP 80 µg/ml, 5-FU 5 µg/ml or the combination of both was performed at different time points throughout 24 hours, and the means of three replicates are shown for every time point. While the mdr-1 mRNA is not signicantly changed, the vATPase mRNA is upregulated in the 5-FU+OMP group after 24 hours compared to control.</p

Western Blot analysis with LC3B-antibody in ASPC-1 and MiaPaCa-2 cells.

<p>The experiment was repeated three times with nearly identical results. The LC3-I fractions can be clearly distinguished above the LC3-II signals. Bafilomycin A1 elevated slightly the LC3-II signal intensity compared to control in both cell lines. There was a marked and dose-dependent increase of the signal strength of both fractions when OMP was used. 5-FU alone did not relevantly influence the LC3-level. The corresponding β-Actin level is shown below the LC3-WB to confirm the correctness of this semiquantitative evaluation.</p

Simplified metabolic network of the MiaPaCa-2 cell line as determined by proton NMR spectroscopy.

<p>The 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 colors 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. Upon OMP, the PC/Cho ratios are significantly lower compared to control. Furthermore the acetate/FACH2 ratio is significantly decreased in the OMP group. The latter also showed a higher CH = CH level, the ratio to FACH2 is, however, decreased. Upon 5-FU and 5-FU+OMP, similar changes could be observed. Furthermore, in contrast to ASPC-1 cells, the Ala/Gln/AMP pathway is also involved. 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.</p

Hormesis of low-dose 5-FU in pancreatic cancer cells and interaction with OMP.

<p>The cell lines ASPC-1, MiaPaCa-2, Colo357, Panc-1, Panc89 and PancTu1 were untreated or treated with 5-FU alone or in combination with the indicated concentrations of OMP for 4 days. At lower doses of 5-FU alone (black lines, 0 µg/ml OMP) a growth-stimulatory effect (hormesis) was observed in the cell lines ASPC-1, Panc-1 and PancTu-1. The data points show the means of 8 measurements. The curves are fitted in these cell lines using the Brain-Cousens model (see sub-section 4.11). In MiaPaCa-2 and Panc-89 cells no hormesis occured, these curves were fitted using a three parameter logistic model. In Colo357 cells the curves could not be fitted by any pharmacodynamic model due to large standard errors at these lower concentrations (data points shown). The red, green and blue lines indicate the dose-effect curves of 5-FU when various concentrations of OMP were added (10, 20 and 40 µg/ml, respectively). In ASPC-1 and Panc-1 cells the hormesis of 5-FU was reversed and in PancTu-1 cell it was mitigated by OMP depending on the concentration of 5-FU. In MiaPaCa-2 cells we found an additive interaction of 5-FU with OMP. In Panc-89 cells the interaction was antagonistic.</p

Electron microscopy of the ASPC-1 and MiaPaCa-2 cell lines treated or untreated with OMP.

<p>(A) ASPC-1 cell without treatment (800 fold). (B) ASPC-1 cell undergoing apoptosis upon 160 µg/ml OMP after 24 hours (800 fold). Vacuolisation of the cytoplasma and condensation of the nucleus are visible. (C) Phagophores and autophagosomes in a segment of an ASPC-1 cell treated with omeprazole 80 µg/ml for 24 hours (2800fold enlargement). The phagophores are characterised by a cup-like shape (white arrows). Autophagosomes are closed particles, the number of which is increased in treated cells (black arrows). (D) Early phagophores and autophagosomes are also found in MiaPaCa-2 cells treated with OMP 80 µg/ml after 24 hours in a perinuclear region containing lysosomes and the Golgi complex. In contrast to ASPC-1 cells, early signs of apoptosis such as vacuolization, are also present. (E) Barchart of the numbers of autophagosomes and lysosomes per cell in MiaPaCa-2 and ASPC-1 cells untreated or treated with 5-FU, OMP or the combination of both for 24 hours with standard errors. Significant differences compared to control are marked by *. In ASPC-1 cells there were significant differences compared to the control in the OMP group (p: 0.03) and the 5-FU+OMP group (p: 0.03). In MiaPaCa-2 cells the 5-FU+OMP group differed significantly from control (p<0.001).</p