Figure 1.

p21^CIP1 up-regulation is temporally related to c-Myc down-regulation after TGFβ treatment of HaCaT cells. (A) HaCaT cells were treated with 1 ng/ml TGFβ for the time periods indicated. Samples were analyzed by Western blot with anti-Mycfl for c-Myc protein expression and by Northern blot for p21^CIP1 mRNA expression. The Northern blot was subsequently probed for cyclophilin as a control for equal loading. (B) Densitometric analysis of Western and Northern blots. The highest value for each c-Myc protein and normalized p21^CIP1 mRNA was set to 1.0 for graphical representation. c-Myc protein levels are indicated by diamonds, and p21^CIP1 mRNA levels normalized to cyclophilin expression are represented by squares.