CD133+CXCR4+ colon cancer cells show higher migratory capacity than CD133+CXCR4- cancer cells in vitro. (A) For in vitro and in vivo experiments, HCT116 cells were double-stained for CD133 and CXCR4. Four distinct phenotypic subpopulations, specifically CD133-CXCR4-, CD133-CXCR4+, CD133+CXCR4- and CD133+CXCR4+, were isolated. (B) Clonogenic ability of the four phenotypic subpopulations was examined using clonogenic assay. A representative photograph is provided in the left panel, and quantified data of three independent experiments are shown in the right panel. (C) Transwell cell migration assays were performed to compare the migratory capacities of different phenotypic subpopulations. A representative photograph is shown in the left panel. Quantification of three independent experiments is shown in the right panel. (D) Boyden chamber invasion assays were performed to compare the invasive capacities of CD133+CXCR4+ cells with CD133+CXCR4- cells. A representative photograph is shown in the left panel. Quantification of three independent experiments is shown in the right panel. Bars represent the mean ± SD of invasive cells. (*P <0.01 compared with the CD133-CXCR4- group, †P <0.01 compared with the CD133+CXCR4- group; ×200 magnification).
Zhang et al. BMC Medicine 2012 10:85 doi:10.1186/1741-7015-10-85