Figure 7: Evi/Wls is required for the survival of colon cancer cells in vitro and in vivo.
From: Wnt secretion is required to maintain high levels of Wnt activity in colon cancer cells

(a) Stable Evi/Wls knockdown reduces the clonogenic capacity of colon cancer cells. HCT116, DLD1 and SW480 cells stably transduced with a control (Ctrl) or an Evi shRNA were seeded in six-well plates at 1,000 cells per well, and were stained with crystal violet 14–20 days later. Wells are representative of three independent experiments for each cell line. (b,c) Evi/Wls is required for the formation of primary colon carcinomas in a xenograft mouse model. HCT116 or DLD1 cells were transduced as described in a, were injected subcutaneously (s.c.) into NOD/SCID mice (3 × 105 per mouse) and tumour appearance was monitored over time. Kaplan–Meier plots show the probability of tumour appearance over time. (b) Results from two blinded, independent experiments are shown. CTNNB1 silencing was performed just in one of these experiments. (c) Results from one blinded experiment are shown. n, number of mice per group. *P=0.000201, **P=0.0000354 and ***P=0.0015. P-values were determined by log-rank test. (d) Evi/Wls downregulation reduces tumour volume in vivo. HCT116 cells were transduced as described in a and were injected s.c. (2 × 106 per mouse) into opposite flanks of the same NOD/SCID mice. Eighteen days later, when tumour volumes had reached about 120 mm3, the mice were randomly separated into two groups: one was treated with dox (added to the drinking water) and the other was not. Tumour volume was measured on a weekly basis and the significance for each time point was calculated using the Student’s t-test. The experiment was terminated when tumours in the control group reached about 1,200 mm3. Results are presented as mean tumour volume±s.e.m.