(A) ALK gene silencing by Apt-NS/siRNA. Cultured Karpas 299 cells were treated with Apt-NS/siRNA for 48 h, followed by staining with anti-ALK antibody. Reduction of ALK expression was analyzed by flow cytometry. (B) Apt-NS/siRNA induced significant silencing of ALK gene, leading to cell apoptosis and death. (C) Fluorescence microscopy imaging of induced-apoptotic and dead cells, detected by AO/EB staining at 24 h post treatment with Apt-NS/DOX. Viable and dead cells were stained green and red, respectively. (D) Rates (%) of apoptotic and dead cells detected by AO/EB staining, at 48 h post treatment. Data shown are Mean ± SEM, n=3; ** p < 0.01, ***p < 0.001, NS, no statistically significant difference.