Figure 2

δ-Catenin expression mediated anchorage-independent prostate cancer cell colony formation and tumor xenograft growth replies on the NH ₂ - and COOH-terminal sequences outside armadillo domains. A. Soft agar assays showing that full length δ-catenin, but not its NH₂- or COOH-terminal truncation mutants, promotes CWR22Rv-1 cell colony formation in vitro. Stable cells expressing vector control, full-length δ-catenin, ΔN280 and ΔC207 were plated in soft agar. Colonies were counted under the phase contrast light microscope in 1, 2, 3, and 4 weeks after they were plated. Results were derived from five independent experiments, each in duplicate. * P < 0.05. B. δ-Catenin overexpression promotes CWR22Rv-1 cells to grow tumors in nude mice. Shown here is a representative pair of tumor bearing mice expressing control vector and δ-catenin, respectively (n = 19). C. Full-length δ-catenin, but not its NH₂- or COOH-terminal truncation mutants, promotes tumor xenograft growth in nude mice. Male athymic nude mice were inoculated subcutaneously with either the vector, full-length δ-catenin, ΔC207 or ΔN280 and were then allowed to grow for 5 weeks. Each week, the tumor volumes were measured and compared to each other. * P < 0.05. D. Fluorescent light microscopy showing the tumor cell morphology (a and c) and GFP positive CWR22Rv-1 cells expressing vector alone (b) and overexpressing δ-catenin (d). Bar, 50 μm.