Figure 1. Overexpression of CDK8 abrogates tumorigenesis in KLE cells. KLE cells were stably transduced with retroviral expression vector encoding CDK8 and the empty vector control. (A) The levels of CDK8 and CycC in five endometrial cancer cell lines analyzed by western blots. (B) qRT-PCR analysis of relative mRNA level of CDK8 and (C) western blot analysis of CDK8 protein levels were shown compared with empty vector control after puromycin selection. (D) Growth curve of CDK8 overexpressing KLE cells. Cells (2.0 × 105 per well) were seeded in 6-well plate, and the number of cells per well was shown for 5 d (n = 3). (E) The effects of CDK8 overexpression on cell cycle progression of the KLE cells analyzed by flow cytometry analysis. (F) Tumor growth of CDK8 overexpression or control KLE cells in 6–8-week-old female nude mice (n > 14 separate mice in each group). Cells (2.0 × 105) were implanted in two flanks of each mouse, and the volume of tumors was assessed in indicated days. (G) Tumor weight was measured at the completion of the experiment. The data shown as mean ± SEM from triplicates calculated using two-factor repeated measure analysis of variance followed by Fisher’s last significant different test for multiple comparisons.