Figure 5. GBM cell lines are sensitive to Hippo pathway modulation.

A) U87 cells were treated with increasing concentrations of Verteporfin (0, 2, 4, and 8 μM) after transfection with a YAP-TEAD luciferase reporter (8×GTIIC-luc) and assayed 24 hours later. B) U87 cells were incubated for four days with 0, 2, 4, or 8 μM Verteporfin, and relative cell number determined by counting quadruplicate cultures. C) A172 cells were analyzed as in A and B with 0 or 8 μM Verteporfin. D) U87 cells expressing Myt1 or Myt1l or with the control vector were transiently transfected with the 8×GTIIC-luc reporter with or without a YAP1 expression plasmid, and luciferase activity was determined after 48 hours. E) Cells transfected with the 8×GTIIC-luc reporter and were split at high and low density and assayed for luciferase activity 36 hours later. F) A172 cells expressing Myt1 or Myt1l or with the control vector were transfected with 8×GTIIC-luc with or without a YAP1 plasmid, and luciferase activity was determined after 48 hours. G) U87 cells expressing either Myt1 or Myt1l and control cells were incubated for four days with 0, 2, or 4 μM Verteporfin and relative cell number determined by counting quadruplicate cultures. All luciferase data is presented as mean + sd of triplicate transfections, normalized to a Renilla-luc transfection control. p-values were determined by Student’s T-test: * p < 0.05, ** p < 0.01, *** p < 0.001. Panels A-F show representative experiments, that were repeated twice with similar results. Data in panel G is from a single experiment. Averages shown are of triplicate samples for luciferase assays, and quadruplicates for proliferation assays, from a single representative experiment.