Measurement of TPO and interleukin 3 (IL-3) mRNA expression in BM stromal cells with the addition of PDGF.

PDGF (50 ng/mL) was added to BM stromal cells in culture and incubated for 4 hours. TPO mRNA expression was specifically up-regulated, whereas IL-3 and GAPDH mRNA remained unchanged, as measured by the QISH assay. The results shown are the mean ± SD values from 3 separate experiments carried out in triplicate. *P < .05 compared with controls (time 0). □, 1% serum; ▪, 1% serum plus PDGF.