Figure 1.
Effects of imetelstat on CFU-MK colony formation. (a) CFU-MK colonies formed by untreated CD34+ cells or by CD34+ cells treated with 7.5 and 15 μM of either mismatched control oligonucleotide (MM1) or imetelstat (GRN163L) were enumerated after 14–16 days of incubation in a collagen-based semisolid media in the presence of thrombopoietin, IL-6 and IL-3. Each column represents the average number of small (3–10 MKs), medium (10–50 MKs) and large (450 MKs) colonies ± s.d. enumerated in three independent experiments. (b) CFU-MK formation by PB-MNCs from HCs (n = 8) and from patients with MPN (n = 15) treated with 15 μM of either mismatched control oligonucleotide (MM1) or imetelstat (GRN163L). The vertical axis indicates CFU-MK clonogenic efficiency after normalization to that of untreated cultures. (c) Representative microphotographs of collagen slabs containing CFU-MK colonies (upper panels) and of individual CFU-MK (lower panels) formed by untreated, MM1- and GRN163L-treated PB-MNCs from one representative MPN patient.