MiR-377 effect on soft agar colony formation of melanoma cells. Soft agar colony formation assays were performed using mel-14PA (A) or mel33B1 (B) melanoma cells over-expressing either miR-377 or HTR control vector. Colonies were stained after 3 weeks in culture. Representative photomicrographs are shown in the left panel. Quantification of the area covered by the colonies was performed using the ImageJ software  following three independent experiments (right panel). p value was calculated by t-test; **p < 0.01, ***p < 0.001.