Figure 2: Reduced vessel density and tumour regression upon Tie2-Cre-mediated conditional Wt1 knockout.

(a) Quantification of tumour weights in the B16 (Tie2-CreERT2;Wt1^lox/lox+tamoxifen, n=20; Tie2-CreERT2;Wt1^lox/lox+vehicle, n=13; Tie2-CreERT2+tamoxifen, n=11) and LLC1 (Tie2-CreERT2;Wt1^lox/lox+tamoxifen, n=11; Tie2-CreERT2;Wt1^lox/lox+vehicle, n=9; Tie2-CreERT2+tamoxifen, n=8) tumour model. (b) B16 and LLC1 tumours in Tie2-CreERT2;Wt1^lox/lox+tamoxifen animals and control groups. Each picture shows one tumour. (c) B16 and LLC1 tumour growth curves in Tie2-CreERT2;Wt1^lox/lox+tamoxifen animals and respective controls. (d) Summary of the histological analysis of control animals and of Tie2-CreERT2;Wt1^lox/lox+tamoxifen mice. Results were grouped as tumour, partial or complete regression. (e) haematoxylin–eosin staining of B16 and LLC1 tumours and adjacent tissues at day 27 after tumour cell injection. Note the tumour masses in control animals (left) and the small cluster of remaining tumour cells (arrows) in close proximity to large immune cell infiltrations (arrowheads) in Tie2-CreERT2;Wt1^lox/lox+tamoxifen animals indicating nearly complete regression. The photomicrograph of the LLC1 tumour in the Tie2-CreERT2;Wt1^lox/lox+tamoxifen animal represents complete regression with a remaining central necrosis (CN) surrounded by lymphocyte infiltrations (arrowheads). (f) Pecam-1 immunostaining in B16 and LLC1 tumours. (g) Quantification of Pecam-1 signal area density. Scale bars, 50 μm. Data are the mean±s.e.m. *P<0.05, **P<0.01, ***P<0.001.