Figure 2
VEGF expression was positively correlated with CRT expression and neuronal differentiation in NB cells and NB xenografts. (A) Human stNB-V1 NB cells were stimulated with 1 μg/ml tetracycline to induce CRT expression. Expression of CRT, VEGF and GAP43 was visualized and quantitated by immunofluorescence microscopy and ImageJ. Data are shown as mean fluorescence intensity (±SD) from at least three independent experiments. (B,C) Inducible-CRT stNB-V1 cells were injected subcutaneously into nude mice. Tumor inoculated mice were treated with doxycycline in their daily drinking water (2 g/L) to induce CRT expression. Mice were sacrificed after 15-days treatment and the tumor was removed for experiments. The mRNA expression levels of CRT, VEGF, and GAP43 were confirmed by real-time PCR and were increased after doxycycline treatment. The mRNA expression level was normalized to the internal control HSP60. Each bar of the histogram represents quantified results and is shown as the mean ± SD. Statistical differences were compared with the control level. The expressions of CRT, VEGF and GAP43 were visualized and quantitated by immunofluorescence microscopy. *P < 0.05, **P < 0.01.
