Figure 1
From: A slow-cycling subpopulation of melanoma cells with highly invasive properties
Melanoma cells identified as slow-cycling, LRC are predominantly in the G2/M cell cycle phase and are more invasive in vitro. (a) Six melanoma cell lines were labeled with CellTrace Dye and analyzed at different time points (days 0–4–8–12). Day 0 indicates how the cells appear directly after CellTrace loading. LRC are defined and gated as shown in the dot plots; numbers indicate % of LRC detected on day 12 in culture; standard error of the mean (s.e.m.) in parenthesis. (b) Relative dilution of the CellTrace Dye for LRC (red circles), non-LRC (yellow inverted triangles) and total cells (gray squares). Slopes indicate mean fluorescence intensity ratio between CellTrace-stained and unstained cells. Mean±s.e.m. are reported. (c) Cells were loaded with CellTrace Dye and stained with propidium iodide for cell cycle analyses after 7 days in culture. Percentage of cells in each cell cycle stage is shown in the Y-axes. Data represent mean±s.e.m. Three representative cell lines are shown. (d) LRC (red), non-LRC (orange) and total (gray) were sorted and analyzed by mRNA FISH for JARID1B expression in single cells, with representative images below (total magnification 100 ×). Data indicate that some but not all LRC are JARID1B-positive. Violin plots depict mRNA counts (Y-axes); ns=not significant. (e) Invasive capacity of LRC (red bars) and non-LRC (orange) in Boyden chamber assays after sorting, for three representative cell lines. Data represent mean±s.e.m. of three independent experiments of the fold change of LRC over non-LRC. All reported P-values were determined using a 2-sided t-student test.
