Figure 5.

QKI-5 promotes cell cycle arrest at the G1/S-phase transition through P27 and Cyclin D1, involving MAPK signaling pathway. (A and B) 786-O or A-498 cells stably overexpressing QKI-5 or transfected with empty vector (Vec) were subjected to cell cycle analysis by flow cytometry. Images and qualification of the cell cycle distribution in 3 experiments are shown; *P < 0.05, **P < 0.01, Student t test. (C) Immunoblotting analysis of cyclin A, cyclin D1, cyclin E, and their inhibitors p21 and p27 in the indicated cell lines. α-tubulin was used as a loading control. (D) Immunoblotting analysis of phosphorylated ERK, total ERK, phosphorylated p38, and total p38 in the indicated cell lines. α-tubulin was used as the loading control.