Figure 4. Notch inhibition of CCRCC cells results in elevation of p21^Cip1 and/or p27^Kip1 proteins.

(A) Immunoblotting with a p21^Cip1 antibody of lysates from SKRC-52 cells treated with increasing concentrations of the γ-secretase inhibitor DAPT. Cells were grown in medium containing 1% FCS. DAPT- and vehicle control–treated cells were harvested after 24 hours of stimulation (C, volume of DMSO corresponding to 40 μM DAPT). (B) Immunoblotting of p21^Cip1 after γ-secretase (+) or control (–) treatment of SKRC-52 cells. Cells were harvested at indicated time points. (C) Immunoblotting of p21^Cip1 and p27^Kip1 after γ-secretase (+) or control (–) treatment of 786-O cells. Cells were harvested at indicated time points. (D) p21^Cip1 and p27^Kip1 Western blot analyses of lysates from SKRC-17 and SKRC-21 cells treated for 48 hours with γ-secretase (+) or vehicle control (–).