FIGURE 1.
Effects of wild-type and chimeric C/EBP proteins on proliferation of K562 cells. A, shown is a schematic diagram of C/EBP-ER chimeric proteins. B, a Western blot shows levels of C/EBP-ER proteins in K562 cells detected by anti-estrogen receptor α monoclonal antibody (Stressgen); expression of GRB2, as loading control, was detected by anti-GRB2 monoclonal antibody (610112, BD Transduction Laboratories). Cell counts (C) and cell cycle distribution (D) at 72 h of 4-HT-treated MigRI- or C/EBP-ER-transduced K562 cells are shown; values represent the mean ± S.D. of three independent experiments. * p < 0.05 relative to MigRI transduced K562 cells. E, methylcellulose colony formation of 4-HT-treated MigRI- or C/EBP-ER-transduced K562 cells is shown. Colonies were scored 6 days after seeding 5 × 102 cells/plate; values (mean ± S.D. of two independent experiments performed in duplicate) are expressed as the percentage of colonies from 4-HT-treated cells compared with those derived from the corresponding untreated cells taken as 100%. p values indicate statistical significance of the difference in colony number of untreated MigRI- or C/EBP-ER-transduced K562 cells versus 4-HT treated calculated using unpaired, two-tailed Student's t test.