Suppressing DDX11 expression in melanoma cells leads to inhibition of melanoma cell proliferation and massive melanoma cell apoptosis. ( A) Proliferation of WM1158 MGP melanoma cells that received only Lipofectamine 2000 (black-colored line) or were transfected with 25 nM of control siRNAs (grey-colored line) or 25 nM of DDX11 siRNA (red-colored line). Depicted at each time point following siRNA transfection is the mean of duplicate samples analyzed. (B) Immunoblot analysis of WM1158 MGP melanoma cells, transfected with 25 nM of DDX11 siRNA for 24 hr (d), 48 hr (e), 72 hr (f) or 96 hr (g), were probed with an antibody to c-PARP. Protein lysates prepared at 96 hr from WM1158 cells that were not transfected (a), had received only Lipofectamine 2000 (b), or were transfected with 25 nM of control siRNAs (c) served as controls. For loading control, the immunoblot was probed with an antibody to α-tubulin. (C) WM1158 MGP melanoma cells, transfected for 48 hr with 75 nM of control siRNAs (a) or 75 nM of DDX11 siRNA (b) were analyzed by immunofluorescence-based TUNEL. Melanoma cells that had undergone apoptosis are pseudocolored red (TUNEL staining) and fluorescent DAPI-counterstained nuclei are pseudocolored blue.