Fig. 3

ARP facilitates, and AS1 suppresses proliferation of CD34⁺ progenitors. (A) Low concentrations of AS1 selectively suppress AChE-R in human CD34¹ progenitors. Human CD34¹ cells were incubated for 24 hr with the noted concentrations of AS1, an antisense oligodeoxynucleotide targeted to exon 2 in AChE mRNA. Shown are confocal images taken following in situ hybridization with cRNA probes for the noted transcripts. Graph shows an inverted, sequence-specific, dose-dependent suppression of AChE-R mRNA in CD34¹ cells by AS1. Shown are average fluorescent signals 6 SD measured in confocal projections (20 cells per group) of CD34¹ cells treated with AS1 and subjected to in situ hybridization with AChE-S and -R specific probes. Asterisks note statistically significant differences from control (p, 0.001, Student’s t-test). (B) ARP enhances cell proliferation. Cell proliferation was evaluated by measuring BrdU incorporation following 16 hr incubation in the presence of GM-CSF with or without 50 ng/ml ARP and 20 pM of AS1. Presented are average results of three to six reproducible experiments 6 SEM. Note that ARP enhances GM-CSF-supported increases in cell proliferation, that AS1 attenuates this enhancement and that ARP overrides antisense-suppressed proliferation.