Fig. 2

YKL-40 overexpression reduces the malignancy of melanoma cells. (A) Melanoma cell lines with stable overexpression of YKL-40 were established using a retroviral transfection method. The expression levels and secretion of YKL-40 were detected by western blotting. pBabe, empty backbone vector. YKL-40, over-expressing vector. Original blots are presented in Supplementary Figure S3. (B) A375 and B16F10 cells were seeded in a 60-mm culture dish at a density of 200 cells/plate and cultured for 2 weeks to form colonies. The cell colonies were stained with crystal violet. (C and D) Colony areas were quantified using Fiji-ImageJ (bars, SD; t-test; ^**P<0.01; n = 3). (E and G) Monolayers of A375 or B16F10 cells were scratched with a 200 µl pipette tip when 95% confluence was reached. Representative images of migrating cells were captured under an inverted microscope (magnification, x40). (F) The migration of A375 cells was quantified based on the wound closure area 24 h after scratching (migration area / wound gap area; bars, SD; t-test; ^***P<0.001; n = 7). (H) The migration of B16F10 cells was quantified based on the wound closure area 20 h after scratching (migration area / wound gap area; bars, SD; t-test; ^**P<0.01; n = 8). (I) B16F10 cells that migrated to the bottom side of the Transwell chamber were fixed and stained with DAPI. Representative images of migrating cells were captured under an inverted microscope (magnification, x100). (J) The number of migrated cells was quantified using Fiji-ImageJ (bars, SD; t-test; ^**P<0.01; n = 4). YKL-40, chitinase 3 like 1.