Arp2/3 complex inhibition rescues the proliferative and nuclear defects caused by CA-WASp. (A-B) Percentage of (A) U937 and (B) HT1080 cells expressing GFP-CA-WASp 3, 6, 8, 10, 13, and 15 days after transduction cultured with DMSO, 20μM or 40μM CK666; n = 3, mean ± SD. (C) Apoptosis measured by flow cytometry of annexin V–stained U937 cells after culture for 3-8 days in the conditions shown, with (■) and without (▩) CA-WASp expression, n = 8. Percentage of binucleated (D) U937 and (E) HT1080 cells after culture for 3-10 days in the conditions shown, n = 8. Control (▩); CA-WASp (■). (F-G) Percentage of micronucleated (F) U937 and (G) HT1080 cells after culture for 3-10 days in the conditions shown, n = 6. ■ indicates cells with micronuclei alone; and ▩, binucleated cells with micronuclei. (H) Lagging chromosomes at anaphase in HT1080 cells. Bar = 10 μm. (I) Percentage of HT1080 cells with lagging anaphase chromosomes; n = 3 with at least 300 cells analyzed per condition. Confocal microscopy was performed as in Figure 2.