Effect of Nck2 on actin organization and focal adhesions in human primary melanoma cells. (A) WM278 human primary melanoma cells overexpressing GFP (C2) or increasing levels of GFP-Nck2 (N15 < N7 < N14) were submitted to actin staining using phalloidin-coupled to AlexaFluor®555. Pictures were taken at 40X and white bar represent 20 μm. (B) Fluorescence pictures of WM278 human primary melanoma cells stably overexpressing GFP (C2) or GFP-Nck2 (N14) subjected to vinculin staining using anti-vinculin specific antibody and GAM-TRICT (63X, white bar: 20 μm). (C) Manual quantification of focal adhesions as positive vinculin structures in 50 representative cell types. Results normalized for cell size are expressed as the mean of focal adhesion per mm2 or cell ± SD. * p < 0.001 vs C2 using Student's t-test.