Enhancement of the dormancy of the cancer cells in the lung by the inhibition of CXCR4.

<p>(A) Quantification of the expression levels of the <i>Cxcl12</i> mRNA in the orthotopic tumor and the lung tissues by real-time quantitative reverse transcription PCR. The expression levels of the mRNA were normalized to those of <i>Gapdh</i> as an internal standard (orthotopic tumor: n = 5; lung: n = 4). No significant difference was observed between these two tissues. (B) Immunofluorescent images for CXCL12 in the orthotopic tumor and the metastatic lesions in the lung. The anti-CXCL12 mAb recognized both mouse and human molecules. The immunofluorescence signal for human leukocyte antigen (HLA)-A,-B,-C was not detected under the fixation conditions used here, but it was observed under the different fixation conditions used in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0130032#pone.0130032.g001" target="_blank">Fig 1B</a>. Red: CXCL12; blue: nucleus. Scale bars: 50 μm. Representative images are shown. (C) Immunofluorescent images for Ki-67 in the metastatic lesions in the lung of the mice administered with or without AMD3100. Green: HLA-A, B, C; red: Ki-67; blue: nucleus. Scale bars: 100 μm. Representative images are shown. The area in the white boxes are magnified 2.5-fold in size and shown in the insets. The arrowheads indicate the Ki-67-positive metastatic cancer cells in the lung. (D) The rates of the Ki-67-positive MDA-MB-231 cells in the metastatic lesions in the lung. The number of the Ki-67-positive or negative cancer cells was manually counted in twelve high power fields, and the rate of the Ki-67-positive MDA-MB-231 cells were calculated. (** p<0.005).