Figure 6.

MKK3 depletion affects xenograft tumor growth and increases chemotherapeutic response in vivo. (a) Dose-response effect of 5-FU on clonogenic survival in HT29-sh/scr and sh/MKK3 cell lines, DOXI-induced for 48 h, and then treated with 5-FU (1, 2, 5, and 10 μM) for 24 h. After treatment, the culture medium was replenished, and cells were maintained at 37 °C for 14 days. Grown colonies were stained with crystal violet. (b) Efficient MKK3 depletion was achieved in vivo, assessed by western blot analysis performed on a representative number of xenograft tumors generated with sh/scr and sh/MKK3 engineered HT29 cancer cells injected in nude mice (CD1/SWISS). Numbers identify single animal. (c) After tumor nodule formation, DOX (2.0 g/l, tap water) was delivered to all mice. To assess chemotherapeutic response in MKK3-depleted tumors, 5-FU (50 mg/kg, intraperitoneal) was delivered to a subgroup of sh/scr and sh/MKK3 tumor-bearing mice (8 mice/group). Tumor growth was followed by calliper measurements twice a week. Representative data of two independent experiments are reported. Student's t-test analyses were performed to assess significance between sh/scr and sh/MKK3 tumor-bearing mice (P<0.05) and along with 5-FU treatments (P=0.01)