Fig. 1
PAMs reduced MAO A activity and cell growth in glioma cells in vitro. a PAMs inhibited MAO A catalytic activity. The effect of PAMs on MAO A catalytic activity was determined in mouse glioma GL-26 and human prostate LNCaP cells. PAMs at appropriate concentrations were pre-incubated at 37 °C for 20 min, then the substrate serotonin (5HT) was added for MAO A catalytic activity assay, see text for detail. 100% of MAO A catalytic activity was 36.65 or 29.86 nmol/20 min/mg in prostate cancer or glioma respectively. b Effect of PAMs. on cell growth in human glioma TMZ-sensitive (U251S), TMZ-resistant (U251R) and mouse GL- 26 cells as determined by MTS assay. 5 × 103 cells were seeded in each well, incubated with PAMs at (0-150 μg/ml) for 48 h, MTS assay was then performed. c PAMs in combination with low dose TMZ reduced cell growth in U251S, U251R, and GL-26 cells. Cells were treated with PAMs (50 μg/ml), TMZ (15 μM), PAMs (50 μg/ml) + TMZ (15 μM) for 48 h, MTS assay was then performance. Data represent the mean ± SEM. The p value was calculated by t-test. *p < 0.05, **p < 0.01, ***p < 0.001 compared to control (0 μg). #p < 0.05, PAMs (50 μg/ml) + TMZ (15 μM) compared to TMZ alone. d Effect of MAO A inhibitor clorgyline on cell growth. Cells (U251S, U251R, and GL-26) were seeded and incubated with clorgyline (0-200 μM). The IC50 of clorgyline is 56.5, 46.4, and 46.4 μg/ml for U251S, U251R, and GL-26 cells. Experiments were performed in triplicate and repeated three times with similar results (n = 3)