Figure 4. Orthotopic tumors derived from Cav1-silenced PC3(−) cells showed a significantly increased tumor growth and epithelial Cav1 (re-) expressions.
(A) PC3 (+/−Cav1) cells were injected into the right and left dorsolateral lobe (0.5 × 105 cells per lobe) of the prostate of NMRI nude mice. Tumor weight and volume was determined 14 days after tumor cell implantation. Data are presented as mean ± SEM from 3 independent experiments (16 mice in total: PC3(+) n = 7; PC3(−) n = 9); *P ≤ 0.05, **P ≤ 0.01 by two-tailed t-tests with Welch’s correction. (B) Expression levels of the indicated proteins were analyzed in whole protein lysates using Western blot analysis. Representative blots are shown. (C) Tumors derived from shCav1 PC3 cells as well as from shCtrl control cells with normal Cav1 expression were subjected to immunohistochemistry with Cav1 antibody. Representative images are shown. Sections were counterstained using hematoxylin. Arrows point towards Cav1-positive epithelial cells within tumors derived from implanted PC3(−) cells. Magnification 20x. (D) Orthotopic grown tumors were further analysed by immunofluorescence and confocal microscopy. Tumor stroma was stained for Tagln (red) and Cav1 (green). Representative images from at least three independent experiments are shown. Magnification 63x (scale bar 50 μm).