FIGURE 6.

Phospho-Thr-120 reduces the Mst1 diminution of sphere formation in Matrigel ex vivo and tumor formation in mice. A, three-dimensional cell growth (sphere formation) in Matrigel. Equal numbers of C4-2/vector, Mst1-WT, or Mst1-T120A cells were seeded. The cells were grown for 10 days in the presence of Dox (0.5 μg/ml). The graph is the quantification of spheres. Engineered C4-2 cells in all experiments were grown in serum-fed conditions. Data are representative of multiple experiments. B, tumor formation in xenografts. C4-2/vector (n = 10), C4-2/HA-Mst1-WT (n = 6), or C4-2/HA-Mst1-T120A (n = 3) cells were subcutaneously inoculated into intact nude male mice (10 animals per group). Animals were treated with Dox (0.5 mg/ml) in drinking water for 6 weeks. Tumor sizes were measured weekly. Tumor volumes were presented as a function of time for each group. C, IHC analysis of HA-Mst1 expression in tumor xenografts. Tissue sections were stained with HA tag antibody. Blue stained the nuclei. Magnification was ×200. Images are representative of multiple experiments.