Fig. 1.

MTX treatment increases the expression and activity of CD73 and the production of adenosine in C6 glioblastoma cells in vitro. C6 glioblastoma cells were seeded into plates and treated with 1.0 μM MTX for 24 h. After treatment, CD73 expression (n = 3) was analyzed (a) and AMP hydrolysis was measured by the malachite green method (n = 3) (b) or by HPLC after a 30- (c) or 60-min (n = 2) (d) incubation as described in the “Materials and Methods” section. The values represent the mean ± SEM. Asterisk indicates a significant difference from the DMSO vehicle group (p < 0.05) as determined by Student’s t test