Fig. 4
Treatment of HUVECs with tumor conditioned medium increases Akt, but not NHE1, protein expression. a VEGF content in MCF-7 conditioned medium (MCF-7 CM) based on quantification of ELISA results. MCF-7 cells were grown under TME conditions (1% O2, 1% FBS, 2.5 mM glucose, 7.5 mM lactate and pH 6.5) for 24 h, and medium collected for ELISA. Data are presented as mean with SEM error bar (n = 4). ** indicates p < 0.01, one-sample Student’s t-test against baseline. b, c HUVECs were exposed to standard TME conditions or to TME conditions with freshly prepared MCF-7 CM for 24 h followed by lysis and western blotting. Representative western blots and quantification of total protein levels relative to that for cells grown under standard TME conditions are shown for Akt1 (b) and NHE1 (c). GAPDH is shown as loading control. Data are presented as means ± SEM, with n = 4 per condition. * indicates p < 0.05, two-tailed paired Student’s t-test