Figure 4.

RT-PCR analysis of six representative K562 clones containing integrated rAAV/HS2αβ^AS3. K562 cell clones were treated with sodium butyrate (BU) or trichostatin A (TSA) for 24 h; untreated cells were included as controls (CTL). Total RNA was extracted with RNA STAT60. RT-PCR of endogenous α-globin mRNA served as an internal control. A dramatic induction of αβ^AS3 gene expression was observed in half of the clones. The level of butyrate induction was 8.1-fold for clone 237, 33-fold for clone 396, and 9-fold for clone 658. The level of trichostatin A induction was 10.2-fold for clone 237, 19-fold for clone 396, and 14-fold for clone 658. Overall, β^AS3 expression was inducible in 6 of the 13 clones, and the average level of induction was 10.6-fold and 9.0-fold for butyrate and trichostatin A, respectively. Expression of αβ^AS3 in the other half of the samples was constitutive as illustrated by clones 260, 354, and 394.