Skip to main content
. Author manuscript; available in PMC: 2017 Apr 17.
Published in final edited form as: Leukemia. 2016 Oct 17;31(3):688–696. doi: 10.1038/leu.2016.284

Figure 4. Knockdown of DOCK2 results in increased sensitivity to ARA-C in cell lines that express FLT3.

Figure 4

(A) Stable knockdown of DOCK2 expression increases the fraction of cells in late apoptosis upon treatment with ARA-C (48 hr) in cell lines with elevated FLT3 activity (SEM K2: P ≤ 0.001, ***; HB11;19: P ≤ 0.01, **; MV4;11: P ≤ 0.01, **). The ARA-C concentration used for each cell line was the IC50 as determined by MTT assay. (B) Induction of anti-DOCK2 shRNA by doxycycline treatment increases the fraction of cells in late apoptosis upon treatment with ARA-C (48 hr) in MV4;11 cells (P ≤ 0.01, **) but not TF-1 cells. (C) Proliferation assays demonstrate that stable knockdown of DOCK2 results in increased cell death upon treatment with ARA-C in MV4;11 cells (P<0.0001, ***) but not REH cells. Cells were seeded at a relatively high density (0.5 million cells/ml) to visualize differences in the proliferation of ARA-C treated cells. (D) Combination treatment of DOCK2-deficient MV4;11 cells with ARA-C (2500 nM) and FLT3 inhibitors increases the percentage of apoptotic cells over that seen with ARA-C or FLT-3 inhibitor treatment alone. Cells were treated for 48 hr. FLT3 inhibitors include sorafenib (SB; 25 nM), CEP-701 (5 nM), and AC220 (4 nM). Statistically significant differences were seen between ARA-C alone and ARA-C+SB (P ≤ 0.01, **), ARA-C+CEP-701(P ≤ 0.01, **) and ARA-C+AC220 (P ≤ 0.001, ***), as well as SB alone and ARA-C+SB (P ≤ 0.01, **), CEP-701 and ARa-C+CEP-701(P ≤ 0.001, ***), and AC220 and ARA-C+AC220(P ≤ 0.001, ***). All assays were performed in triplicate.