Figure 6.

Inhibition of Cot1 expression by siCot1 oligonucleotides enhances the SIL/1,25D-induced increase in P-p27^Kip1(Ser10) and p27^Kip1 expression in a cell type-dependent manner. (A) HL60 cells and (B) U937 cells were transfected with siCot1 or siControl RNA. Following 48 h, cells were exposed to the indicated agents for an additional 48 h. The whole cell lysates were then prepared and subjected to western blot analysis and relative P-p27 (Ser10) and p27^Kip1 protein levels were determined by densitometry. The bar graph below each representative blot shows mean OD values ± SD of three experiments. Since there was some minor variability between the blots, the individual signals shown on the blots are not always representative of the mean. Asterisk * indicates, p < 0.05 for the comparison of cells transfected with siCot1 RNA and exposed to 1,25D and SIL/1,25D vs. corresponding samples transfected with siControl RNA (n = 3). Note that the difference between lanes 7 and 8 was only apparent in HL60 cells.