Figure 6. Tumor suppressive role of CDO1. A.

. The MTT assay was performed in HCT116 clones stably expressing CDO1 or control clones. Cell growth was expressed as absorbance (Abs) at 570 nm wavelength. Two independent experiments were done in triplicate, and values are expressed as means ± SD. *, P<0.05 in T-test. B, Colony focus assays were performed in the HCT116 clones after incubation in the presence of G418 for 10 days. Colonies were stained with 0.4% crystal violet solution (MeOH/10% Acetic acid, 3∶1). After air-drying, colonies were photographed under a microscope (right). Values are expressed as means ± SD and are derived from experiments done in triplicate. C, Inhibitory ability of CDO1 in anchorage-independent cell growth was determined by the soft agar assay. Colonies at size >0.5 mm were counted (left). Colonies were photographed under phase-contrast microscope (middle) or under UV after staining with ethidium bromide in 1 × PBS/0.1% Triton X-100 solution overnight (right). Scale bar, 500 µm. D, The MTT, colony focus (E) and soft agar assays (F) were performed in DLD-1 clones stably expressing CDO1 or control clones. F, Colonies were photographed under a phase-contrast microscope (right top) or under UV after staining with ethidium bromide in 1 X PBS/0.1% Triton X-100 solution overnight (right bottom). G, DLD-1-pCDO1-#2 and DLD-1-p3.1 cells were injected on the right flank of 6-week-old nude mice (n = 5 each), and the time course of tumor growth was measured once a week for 4 weeks with caliper (left). Each point represents the mean ± S.D. of tumor volumes of mice in each group. At day 28 after injection, pictures were taken before mice were sacrificed (right). *, P<0.05 in T-test.