Cellular effects of Sirt1 overexpression To test whether high Sirt1 expression also
ARN-509 has a cellular ef fect in vitro, we performed overexpression experiments in both cell lines, MiaPaCa 2 and PANC 1, respectively, using cells upon transfection with flag tagged Sirt1 as determined by MTT assay and Xcelligence proliferation assays, Nicotinamide and gefitinib treatment in cells with endogenous or overexpressed Sirt1 Inhibition of Sirt1 by increasing concentrations of nico tinamide led to a stepwise decrease of viable cells as depicted in Figure 5. Gefitinib treatment with concentra tions of 50 uM showed similar effects as observed for the application of 25 mM nicotinamide. Interestingly, combinatory treatment with 50 uM gefitinib and 25 mM or 40 mM nicotinamide showed a synergistic effect on cell viability, which was observed in both cell lines.
Next, we asked whether inhibition of Sirt 1 by nicotina mide may counterbalance the beneficial effect on cell sur vival triggered by Sirt1 overexpression. We found that
AT7519 価格 application of 10 mM and lower concentrations of nicotina mide, which in untransfected cells already showed a strong flag tagged Sirt1. Overexpression of GFP served as control. Figure 3A shows immunoblots for endogenous and overexpressed Sirt1 in both cell lines. Cells overexpressing Sirt1 showed a markedly stronger immunosignal compared to their untransfected counterparts, which can also be depicted quantitatively as displayed in Figure 3B.
Compared to GFP transfected cells, both cell lines showed statistically significantly increased amounts of viable, proliferating decrease of viable cell fractions compared to controls did not influence cell viability in cells overexpressing Sirt1, while
オーダー Alisertib higher concentrations of nicotinamide abrogated increased cell viability mediated by overexpressed Sirt1. Cellular effects of cambinol, gemcitabine and gefitinib treatment Proliferation assay Real time proliferation assays revealed an inhibition of cell growth of Mia PaCa 2 cells and PANC 1 cells over a time period of 72 hrs upon treatment with cambinol. While for Mia PaCa 2 comparably lower concentrations of cambinol were necessary to achieve this effect, for PANC 1 cells concentrations up to 100 uM had to be applied, Combination of cambinol and gefitinib led to a synergistic inhibitory effect on cell growth for both cell lines.
As in the previous experiment slightly higher concentrations for cambinol as well as for gefitinib were used to achieve comparable results in PANC 1 cells. As expected in Mia PaCa 2 comparably low concentra tions of gemcitabine alone led to strong growth inhibitory effects, while in PANC 1 comparably higher concentra tions were necessary, Although we tested a multitude of different treatment schemes, a syner gistic effect for treatment with gemcitabine and cambinol in combination was not observed, Cell cycle analysis To determine the nature of the cellular growth inhib ition, we performed FACS analyses. For PANC 1 cells treated with either cambinol or gefitinib alone or in combination, a sub G1 peak was observed indicating apop tosis, which was also evident by demonstrating cleaved PARP by immunoblot, Cell cycle ana lysis of Mia Paca 2 cells showed a cell cycle arrest for differ ent concentrations of cambinol and for a combinatory regimen of cambinol and gefitinib, but in our experimental setting no appar ent apoptosis induction.