Fig 4. Effects of BST2 on RUNX2 expression.

hAD-BMSCs transfected with siRNA were cultured for 5 days in the presence or absence of OS, and RT-PCR (A), qRT-PCR (B), and immunoblot analyses were performed. GAPDH was used as an internal standard, and the relative expression of RUNX2 was normalized to the expression levels in of cells treated with OS alone. qRT-PCR data showed that RUNX2 expression was reduced following BST2 knockdown with siBST2 #1 and #2. To determine protein expression, the cells were lysed and the proteins were analyzed by SDS-PAGE and immunoblotting (C). The band densities for RUNX2 were normalized to those for β-actin. RUNX2 mRNA and protein expression were significantly reduced following BST2 knockdown by siRNA. Data are expressed as means ± SEM (n = 4, **P<0.01vs. OS-treated control).