Fig. 2.

SPRY2 suppression inhibits cell proliferation of GBM but not of normal human astrocytes. (A and B) U87, GSC1, or GSC2 cells expressing doxycycline-inducible SPRY2-shRNA were treated with or without 1 µg/mL doxycycline for 72 hours, and SPRY2 protein levels were determined by immunoblot. For reconstitution of SPRY2 expression in U87 tet-SPRY2sh cells, RNAi-resistant Flag-tagged SPRY2 was used. (C and D) Doublings per day of U87, GSC1, or GSC2 transduced with luciferase-shRNA (tet-Ctrlsh) or tet-SPRY2sh as assessed by cell counting. (E) Human astrocytes transduced with tet-Ctrlsh or tet-SPRY2sh were treated with or without 1 µg/mL doxycycline for 72 hours, and SPRY2 protein levels were assessed by immunoblot. (F) Measurement of human astrocyte proliferation as doublings per day. Mean ± SEM of at least 3 independent experiments. *P < 0.05, **P < 0.01.