Figure 4.

Tipifarnib reduces cell proliferation and small GTPases activity. Proliferation of (A) HPAECs or (B) HPASMCs cultured in media containing 1% FBS in normoxia or in hypoxia with or without tipifarnib for 72 h (0.1 µmol/L; BrdU assay). Cells in positive controls were stimulated with 10% FBS. Activities of (C) RhoA, (D) RhoB and (E) Ras were assessed in lungs of mice exposed to normoxia or chronic hypoxia and treated with either vehicle or tipifarnib, as indicated. β-actin was used as a normalization control. Data represent mean fold- change ±SEM of n = 5. *P < 0.05, **P < 0.01 vs. normoxic control; ^#P < 0.05, ^##P < 0.01 vs. hypoxic control. 1-way ANOVA with Tukey post-test.