The AML cell line THP-1 displays an siRhoH phenotype. (A) THP-1 cells were either transfected with HA-RhoH or the empty vector, lysed and separated by SDS-PAGE. Detection of HA-RhoH was performed with an HA-specific antibody and enhanced chemiluminescence. As a loading control, the expression of β-actin was detected. (B) THP-1 cells transfected with HA-RhoH or the empty vector were analysed for CD123 expression by FACS using a CD123-APC antibody. Data are presented as percentage of the mean fluorescence signal for CD123 (mean ± SD, n = 3, *P ≤ 0.05). (C) IRF-1 mRNA expression is decreased in RhoH over-expressing THP-1 cells. Quantification of IRF-1 mRNA expression levels by quantitative SYBR-green PCR in control cells and RhoH-transfected THP-1 cells using human IRF-1 specific primers and GAPDH as a reference gene. Data were normalised to the expression in control cells and are presented as fold induction (mean ± SD, n = 3; ***P ≤ 0.005).