Ross images obtained at necropsy are shown. All mice implanted with 4T1 EPZ004777 chemical information shControl or sh413 cells developed mammary tumors with variation in size. Numbers represent average ?SEM. Scale bar = 5 mm.Mahauad-Fernandez et al. Breast Cancer Research (2014) 16:Page 8 ofAs expected, all mice implanted with BST-2-expressing shControl 4T1luc cells showed early onset and progressive increase in bioluminescence. The increase in bioluminescence signal intensity over time suggests progression and metastasis of cancer (Figure 3A, upper panel, Figure 3B, left, middle panel). Indeed, BST-2-expressing shControl cells formed primary tumors quickly and developed metastatic lesions that could be detected by bioluminescence imaging [32]. In striking contrast, BST-2-suppressed 4T1 cells (sh413) exhibited delayed onset of luciferase bioluminescence and disappearance of expression as measured over45 days (Figure 3A, lower panel; Figure 3B, left, bottom panel). Unlike shControl-implanted mice that developed severe abdominal hemorrhage and intestinal/mesenteric tumors (Figure 3B, center, middle and right panels), sh413implanted mice did not develop hemorrhage and had few intestinal/mesenteric tumors (compare Figure 3B, uninjected – upper panel with Figure 3B, sh413-injected lower panel). Metastasis to the intestine and mesentery were significantly reduced from about 21 tumors in shControl mice (Figure 3B, middle right panel and Figure 3C) to six tumors in sh413 mice (Figure 3B, bottom right panel andFigure 3 Down-modulation of BST-2 in cancer cells reduces mammary cancer metastases. (A) Representative images of PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/27597769 tumor cells tracked in vivo with IVIS imaging at different time points. Images show higher luciferase bioluminescence in 4T1 shControl-injected mice compared to sh413-injected mice. (B) Representative luciferase bioluminescence accompanied with abdominal and gastrointestinal tract (GI tract) gross images of uninjected (upper panel), shControl-implanted (middle panel), and sh413-implanted mice (lower panel). Arrow heads point to mammary tumors (middle column) and intestinal/mesenteric tumors (right column). Scale bar = 5 mm. (C) Number of secondary tumors in intestine/ mesentery plotted as average of all mice. (D) Representative intestine/mesentery histology images from 4T1 shControl and sh413-injected mice confirming increased mesenteric tumors (arrows) in shControl mice compared to sh413-injected mice. A mesenteric lymph node is demarcated by an asterisk (not to be confused with a tumor mass). (E) Representative gross liver images of 4T1 shControl and sh413-injected mice. Arrows are pointing to tumors. (F) Representative gross images of lungs showing visible pulmonary nodules (arrows) in shControl-implanted mice. (G) Percent incidence of liver and lung metastases. (H) Lung histology from shControl (upper left) and sh413 (upper right) injected mice. Lung from the 4T1 shControl mice had multiple large tumors (tumors demonstrated by asterisk) and marked infiltration of the alveolar septa and alveolar spaces by neutrophils (yellow arrows). Boxed regions are shown at higher magnification (40X) for shControl (lower left) and sh413 (lower right). Error bars represent standard deviations and significance was taken at P <0.01**.Mahauad-Fernandez et al. Breast Cancer Research (2014) 16:Page 9 ofFigure 3C). Histology confirmed increased intestinal/ mesentery tumors in shControl-implanted mice compared to sh413-implanted mice (Figure 3D, arrows). These findings were c.