Suppression of TrkB abrogates tumor peritoneal dissemination in vivo.

<p>A. Cells were injected i.p. into mice. Abdominal colonization was measured using fluorescence images at 3, 14, 21 and 28 days after injection. The color bar shows photon intensity. B. A bar graph of the average fluorescent signal intensities from 5 mice at day 3, 14, 21 and 28 after injection is shown (**<i>p</i><0.01; NS, not significant). C. Pathologic characteristics of dissemination in TrkB knockdown and TrkB over-expression xenografts. A significantly lower tumor burden was observed in mice from the HEC-1B^sh−TrkB group compared with those from the HEC-1B^NT group as indicated by black arrows. D. Left: Average volume of tumor dissemination in the HEC-1B^sh−TrkB group was lower than that in the HEC-1B^NT group (n = 5, **<i>p</i><0.01). Right: There is no significant difference in the average volume of tumor dissemination between the Ishikawa^TrkB group and the Ishikawa^EV group (n = 5, NS, not significant). E. H&E staining, IHC, and TUNEL analysis of tumors sections. Upper: Alterations in N-cadherin and E-cadherin were confirmed by IHC (200×). Apoptotic cells (green, 200×) were increased in the HEC-1B^sh−TrkB group. Lower: Alterations in E-cadherin and N-cadherin were confirmed by IHC, and apoptotic cells were decreased in Ishikawa^TrkB group mice. All experiments were repeated at least three times.