Figure 7
From: Methylnaltrexone Potentiates the Anti-Angiogenic Effects of mTOR Inhibitors
3,4-Dephostatin inhibition of tyrosine phosphatase activity blocks MNTX synergistic effects with temsirolimus on inhibition of VEGF-induced angiogenic events. Panel A: Bar graph representation of human EC plasma membrane-associated tyrosine phosphatase activity (see Methods) with VEGF (100 nM), morphine (100 nM), MNTX (100 nM) or combination treatment. The asterisks indicate a statistically significant difference (p < 0.05) between control and drug challenge. In addition, there is a statistically significant difference (p, 0.05) between without MNTX and with MNTX treatment. Panel B: Bar graph representation of the ration of phospho-protein to total protein using immunoblot analyses of pSer473Akt, pThr308Akt and pTyr418Src of human EC treated with 100 nM VEGF with or without 10 nM or 100 nM MNTX in the presence or absence of the tyrosine phosphatase inhibitor, 3,4-dephostatin (50 μM). Experiments were performed in triplicate. Error bars = standard deviation. Panel C: Graphical representation of the 50% inhibition concentration (IC50, (nM)) of human EC assayed for VEGF (100 nM)-induced proliferation (24 hours) of temsirolimus with or without 10 nM MNTX in the presence or absence of the tyrosine phosphatase inhibitor, 3,4-dephostatin (50 μM). Experiments were performed in triplicate. Error bars = standard deviation. Panel D: Graphical representation of the 50% inhibition concentration (IC50, (nM)) of human EC assayed for VEGF (100 nM)-induced migration (24 hours) of temsirolimus with or without 10 nM MNTX in the presence or absence of the tyrosine phosphatase inhibitor, 3,4-dephostatin (50 μM). Experiments were performed in triplicate. Error bars = standard deviation.